Hepatitis C virus subtype 3a (HCV-3a) originates from Asia and has spread widely among injecting ... more Hepatitis C virus subtype 3a (HCV-3a) originates from Asia and has spread widely among injecting drug users as well as other patient groups in industrialized countries. HCV subtype 3a infection remains highly prevalent and frequently transmitted in the population of intravenous drug users. The objective of this study was to understand better the mechanisms of the worldwide HCV-3a epidemics in drug users. Ninetythree sera from HCV-3a-infected IDUs from France, the United States, Brazil, Argentina, and Australia were studied. Phylogenetic analyses of the non-structural 5B region showed no specific clustering according to the continent of the patient's origin. Non-exclusive clusters of viral sequences from South America, Australia, and California were observed, but topologies were not supported by strong bootstrap values. The results suggest that HCV-3a has been transmitted from a common origin through a unique worldwide epidemic that rapidly spread among drug users. Regional transmission occurred in the recent past, leading to an embryonic genetic diversification of HCV-3a among local injecting drug user population.
A number of reports have indicated an increased risk of cirrhosis and hepatocellular carcinoma in... more A number of reports have indicated an increased risk of cirrhosis and hepatocellular carcinoma in hepatitis B virus (HBV)-infected individuals carrying HBV e antigen (HBeAg)-negative variants. Although distinct core promoter and precore mutations distributed according to geographical locality and viral genotype have been reported, epidemiological data from South America are still scarce. The prevalences of HBV genotypes and core promoter and precore polymorphisms in 75 HBeAg-negative Argentinean blood donors were surveyed. The observed frequencies of HBV genotypes were 64.0% for genotype F, 17.3% each for genotypes A and D, and 1.3% for genotype C. Genotype F strains were widely distributed and significantly more prevalent in the northern region of the country ( P < 0.001). An overall high proportion of a stop codon mutation (UAG) at precore codon 28 (66.7%) was observed. Wild-type codon 28 (UGG) was present in 29.3% of the samples, and the remaining 4.0% of samples had mixed var...
By using molecular surveillance of hepatitis A virus, we characterized for the first time a subge... more By using molecular surveillance of hepatitis A virus, we characterized for the first time a subgenotype IB imported case in Argentina, a country with universal vaccination since 2005. The case was a crew member of a cruise ship. We consider this a case alert because of its multiple implications.
In this article we discuss the medical diagnoses underlying the most common lawsuits involving pe... more In this article we discuss the medical diagnoses underlying the most common lawsuits involving pediatricians in the United States. Where applicable, specific and general risk-management techniques are noted as a means of increasing patient safety and reducing the risk of medical malpractice exposure.
Exercise stress electrocardiography (ECG) alone is underutilized in part due to poor diagnostic a... more Exercise stress electrocardiography (ECG) alone is underutilized in part due to poor diagnostic accuracy. High-frequency QRS analysis (HF-QRS) is a novel tool to supplement ST evaluation during stress ECG. We compared the diagnostic accuracy and net reclassification of HF-QRS analysis compared with ST evaluation for substantial myocardial ischemia by exercise SPECT myocardial perfusion imaging (MPI). Exercise SPECT MPI was performed in 257 consecutive eligible patients (mean age 59 ± 12, 67% male). An ischemic HF-QRS pattern was defined as a ≥ 1 µV absolute reduction and a ≥ 50% relative reduction of the root-mean-square of the 150-250 Hz band signal in ≥ 3 leads. Left ventricular ischemia of ≥ 10% on SPECT MPI was the diagnostic standard for substantial myocardial ischemia. HF-QRS analysis demonstrated incremental diagnostic value to ST evaluation plus clinical risk factors (AUC 0.804 vs 0.749, P &lt; .0001). A HF-QRS + ST -analysis strategy identified 92.3% of subjects with substantial ischemia and no abnormality in 59.9% of the cohort. No cardiac events occurred in patients without substantial ischemia identified by HF-QRS analysis. In this prospective analysis, exercise stress ECG with HF-QRS analysis identified any and substantial ischemia with high diagnostic accuracy and may allow more than half of referred patients to safely avoid imaging.
This study sought to perform a systematic review and meta-analysis to understand the prognostic v... more This study sought to perform a systematic review and meta-analysis to understand the prognostic value of myocardial scarring as evidenced by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging in patients with known or suspected cardiac sarcoidosis. Although CMR is increasingly used for the diagnosis of cardiac sarcoidosis, the prognostic value of CMR has been less well described in this population. PubMed, Cochrane CENTRAL, and metaRegister of Controlled Trials were searched for CMR studies with ≥1 year of prognostic data. Primary endpoints were all-cause mortality and a composite outcome of arrhythmogenic events (ventricular arrhythmia, implantable cardioverter-defibrillator shock, sudden cardiac death) plus all-cause mortality during follow-up. Summary effect estimates were generated with random-effects modeling. Ten studies were included, involving a total of 760 patients with a mean follow-up of 3.0 ± 1.1 years. Patients had a mean age of 53 years, 41%...
Late versus early acute antibody-mediated rejection (AAMR) or acute cellular rejection (ACR) epis... more Late versus early acute antibody-mediated rejection (AAMR) or acute cellular rejection (ACR) episodes are associated with poorer kidney function and graft survival. We explored whether cell senescence upon detection of AAMR ± ACR contributes to these results. We reviewed the renal transplant database of 2 Institutions. Biopsies performed for acute graft dysfunction from January 2000 to March 2007 were analyzed for morphological criteria of AAMR with or without ACR (n = 17 from 17 patients). Immunoperoxidase staining for p16(INK4B) was performed on the remaining paraffin-embedded tissue in 9 of 17 cases. The average number of positive cells/high power field (HPF) was calculated in every case. Cases with rejection were grouped according to the time of presentation: early (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;3 months n = 8) versus late (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;3 months; n = 9). Graft function was obtained using the Modification of Diet in Renal Disease (mDRD) glomerular filtration rate estimate (eGFR) before, during rejection, and at the last visit, to calculate ΔeGFR. Nuclear expression of p16(INK4B) was 12.2 ± 11.3 cells/HPF in 4 of 8 biopsies performed at a median of 23 (range = 4-80) days (early AAMR ± ACR), and 59.8 ± 51.3 cells/HPF in 5 of 9 biopsies performed at a median of 1171 (range = 279-3210) days (late AAMR ± ACR). eGFR before rejection was 48.5 ± 7.6 mL/min, and 43.7 ± 4.3 mL/min for early and late rejection episodes, respectively (P = not significant [NS]). ΔeGFR of 12.5 ± 25.9 mL/min (early rejection), and -13.7 ± -12.3 mL/min (late rejection), versus last follow-up visit (P = .02) occurred at a median of 143.9 ± 94.1 and 69.6 ± 35.1 weeks after the rejection episodes, respectively. Even though the number of biopsies analyzed for p16(INK4a) was small, it was evident that the number of cells expressing this marker of senescence was higher among biopsy specimens obtained with late rejection episodes. This finding suggests the presence of injuries prior to the rejection episode. The significantly lower eGFR at last follow-up in the late rejection group may translate to a reduced capacity of the repair process to sustain nephron function.
We have examined the structural response of a zinc 2,6-naphthalene dicarboxylate framework solid,... more We have examined the structural response of a zinc 2,6-naphthalene dicarboxylate framework solid, isostructural with MOF-105, to the inclusion during crystallization of dimethylformamide, benzene, toluene, and p-xylene. These compounds, which are made up of a stacked arrangement of four-connected layers, crystallize in the space group P2 1 /c with [Zn 2 (ndc) 2 (DMF) 2 ]‚1.6DMF (1), a) 8.075(1) Å, b) 16.891(2) Å, c) 12.673(2) Å,) 92.90(1)°, [Zn 2 (ndc) 2 (DMF) 2 ]‚C 6 H 6 (2) a) 8.340(2) Å, b) 15.660(4) Å, c) 13.008(4) Å,) 91.340-(5)°, [Zn 2 (ndc) 2 (DMF) 2 ]‚C 7 H 8 (3), a) 8.183(2) Å, b) 16.245(3) Å, c) 12.920(3) Å,) 91.976(4)°, and [Zn 2 (ndc) 2 (DMF) 2 ]‚C 8 H 10 (4), a) 7.973(2) Å, b) 16.946(3) Å, c) 12.922(3) Å,) 92.798(4)°. The structure is found to include p-xylene with high selectivity from mixtures of xylene isomers. In the presence of only o-or m-xylene as an additive, the structure does not crystallize. The mobility of fully deuterated benzene and toluene within compounds 2 and 3 over the temperature ranges 123-294 and 173-294 K, respectively, has been measured by 2 H NMR using the quadrupole echo technique. Benzene is found to execute rapid hopping around its C 6 axis over the entire temperature range studied with an activation energy of 6(1) kJ mol-1. The only motion of the toluene is rapid rotation of the-CD 3 group. Computational modeling of the structures successfully reproduces the crystal structures and the changes in unit cell parameters and indicates that the binding energies of m-xylene within the structure are less favorable than those for p-xylene, predominantly as a result of the distortion of the framework required to accommodate the m-xylene. These lower binding energies explain the high selectivity for the uptake of p-xylene during crystallization.
D-002 is a new natural drug from beeswax with anti-inflammatory and anti-ulcer effects proved in ... more D-002 is a new natural drug from beeswax with anti-inflammatory and anti-ulcer effects proved in different experimental animal models. Pre-clinical toxicology of D-002 showed no drug-related toxicity. The present study was performed to evaluate the effects of D-002 on drug-metabolizing enzymes (Fase I) in male Sprague Dawley rats. The content of P-450 and b5 cytochromes and the activities of the NADPH cytochrome c reductase, aminopyrine N-demethylase, N-dimethylnitrosamine dealkylase, were determined. The biotransformation of benzo(a)pyrene was evaluated by using the Ames test. The results demonstrate that D-002 administered orally at dosis of 50 to 1000 mg/kg/day for one month does not affect the activities of the hepatic drug-metabolizing enzymes investigated. Positive controls treated with phenobarbital and β-naphthoflavone showed significant differences.
In Argentina, a country considered non-endemic for hepatitis E virus (HEV) infection, serologic e... more In Argentina, a country considered non-endemic for hepatitis E virus (HEV) infection, serologic evidence of HEV infection has been observed in different human population groups. In other countries, a high degree of genetic relatedness has been observed between human and swine HEV genotype 3 sequences, suggesting zoonosis as one probable route of infection. This is the first identification of swine HEV in South America. HEV RNA was detected and sequenced in the ORF 1 and ORF 2 regions from swine fecal samples from a herd located in Pergamino, in the province of Buenos Aires. These strains all group into genotype 3 and exhibit a close relationship to two novel HEV variants previously identified in Argentina from sporadic acute cases of non-A to -C hepatitis in humans. In addition, using a modified commercial ELISA, the presence of anti-HEV antibodies was surveyed in five provinces across the country and all five showed a prevalence of HEV antibodies, ranging from 4% to 58%. The results suggest that swine could be an important reservoir for virus transmission in Argentina as has been suggested for other non-endemic areas. The Argentine human strains and swine strain described in this article seem to be closely related to a human Austrian strain, suggesting a potential European origin of HEV infection in these cases.
Current scientific and technological progress has led to the proliferation of e-learning systems ... more Current scientific and technological progress has led to the proliferation of e-learning systems known as Learning Management Systems. These systems consist of a central application for managing the sequencing of students&amp;amp;amp;amp;amp;amp;#x27; tasks, and also on several other educational ...
Here we provide evidence for a critical role of PP2As (protein phosphatase 2As) in the transforma... more Here we provide evidence for a critical role of PP2As (protein phosphatase 2As) in the transformation of Trypanosoma cruzi. In axenic medium at pH 5.0, trypomastigotes rapidly transform into amastigotes, a process blocked by okadaic acid, a potent PP2A inhibitor, at concentrations as low as 0.1 μM. 1-Norokadaone, an inactive okadaic acid analogue, did not affect the transformation. Electron microscopy studies indicated that okadaic acid-treated trypomastigotes had not undergone ultrastructural modifications, reinforcing the idea that PP2A inhibits transformation. Using a microcystin–Sepharose affinity column we purified the native T. cruzi PP2A. The enzyme displayed activity against 32P-labelled phosphorylase a that was inhibited in a dose-dependent manner by okadaic acid. The protein was also submitted to MS and, from the peptides obtained, degenerate primers were used to clone a novel T. cruzi PP2A enzyme by PCR. The isolated gene encodes a protein of 303 amino acids, termed TcPP2...
Pseudolipomatosis is an artifactual microscopic change in tissues that resembles fatty infiltrati... more Pseudolipomatosis is an artifactual microscopic change in tissues that resembles fatty infiltration, most often described in the gastrointestinal tract. The fatlike spaces represent air or gas bubbles that enter the mucosa through microscopic ruptures secondary to gaseous insufflation. We report a series of cases of pseudolipomatosis encountered in gynecologic tissues removed during hysteroscopic procedures, a finding not previously described. We identified 300 consecutive hysteroscopic procedures performed at our institution from 2006 to 2008. Patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; medical records were reviewed to collect pertinent clinical data. Slides from all cases were systematically reviewed. The diagnosis of pseudolipomatosis was established by consensus. Twenty-eight cases of pseudolipomatosis, representing 9.3% of patients who under went hysteroscopy, were identified. Pseudolipomatosis was found in 9 endometrial curettings or biopsy tissues, 8 endometrial or endocervical polyps, 8 uterine fibroids, 2 fallopian tubes, and 1 endocervical biopsy. The type of distention medium used and length of hysteroscopic procedure did not differ significantly between cases with and without pseudolipomatosis. Pseudolipomatosis vacuoles varied in distribution from crowded clusters to sparsely scattered and solitary. Occasionally, vacuoles were found in vascular channels. Vacuoles were round or ovoid, unilocular, and variable in size. Immunohistochemical staining for adipocyte and endothelial markers were negative. We hypothesize that pseudolipomatosis derives from air that is almost invariably introduced into the uterus during media insufflation for hysteroscopy, creating a bubble under pressure. The air enters tissues either through lining microruptures or during the biopsy procedure. Pseudolipomatosis is a relatively common, easily overlooked finding in hysteroscopically derived specimens that may be misdiagnosed when prominent.
This paper presents a model of cross-cultural negotiations which describes how the affect negotia... more This paper presents a model of cross-cultural negotiations which describes how the affect negotiators experience during negotiations influences the character of the negotiation process and its outcomes. Three categories of determinants of negotiator affect are proposed: Individual differences, cross-cultural differences, and contextual factors. The ways in which negotiator affect influences information processing during negotiations are then described. It is suggested
Study objective: To evaluate the e~l~ectiveness of two teaching interventions to increase residen... more Study objective: To evaluate the e~l~ectiveness of two teaching interventions to increase residents' performance of smoking cessation counseling. Design: Randomized controlled factorial trial Setting: Eleven residency programs, in internal medicine (six), family medicine (three), and pediatrics (two). Pro. grams were located in three university medical centers and four university-affdiated community hospitals. Participants: 261 residents who saw ambulatory care patlents at least one half-day per week, and 937 returning patients aged 17 to 75years who reported having smoked five or more cigarettes in the preceding seven days. Of the 937, 843 were eligible for follow-up, and 659 (78%) were interviewed by phone at six months. Interventions: Two interventions (tutorial and prompt) and four groups. The tutorial was a two-hour educational program in minimal-contact smoking cessation counselingfor residents. The prompt was a chart-based reminder to assist physician counseling. One group of residents received the tutorial,, one, the prompt; and one, both. A fourth group received no intervention.
To determine mammography use among women with a broad range of ages, the authors surveyed women a... more To determine mammography use among women with a broad range of ages, the authors surveyed women aged 30 to 74 years and physicians practicing primary care in two eastern North Carolina counties. Twenty-five percent of women in their 30s had ever had a mammogram, and 34% intended to have one in the coming year. From 45% to 52% of women in their 40s, 50s, and 60s had ever had a mammogram, and 55% to 57% intended to have one in the next year. Thirty-seven percent of women aged 70 to 74 years had ever had a mammogram, and 40% intended to have one in the following year. Nineteen percent of physicians reported screening nearly all women aged 30 to 39 years, and 14% screened few women aged 50 to 74 years. Younger women were more worried about breast cancer than older women and assessed their risk as higher, attitudes that were generally associated with higher mammography utilization. These community surveys suggest that mammography use may be excessive among younger women; older women continue to be underscreened.
A method is described for genotyping of hepatitis B virus (HBV), based on the restriction fragmen... more A method is described for genotyping of hepatitis B virus (HBV), based on the restriction fragment length polymorphism (RFLP) created by Ava2 and Dpn2 action on an amplified segment of the pre-S region. Analysing 51 database sequences by phylogenetic tree construction and RFLP prediction, the method was shown to be capable of detecting all known genotypes (A-F). The method was applied to 99 serum samples from hepatitis B e antigen (HBeAg)-positive chronic carriers, comparing observed agarose gel patterns with the RFLP predicted from the database sequences. In 95 typable samples the following genotypes were observed; 23 A, 20 B, 20 C, 22 D, 5 E and 5 F. Phylogenetic grouping of the 51 database sequences and RFLP genotyping of the 99 patient samples were compared with typing based on S gene analysis, showing disagreement in only one case, a database sequence of ayw subtype which was classified as genotype D by pre-S region and genotype A by S region analysis. This method should be useful for epidemiological investigations and for studying the potential influence of genotype on the course of infection.
Hepatitis C virus subtype 3a (HCV-3a) originates from Asia and has spread widely among injecting ... more Hepatitis C virus subtype 3a (HCV-3a) originates from Asia and has spread widely among injecting drug users as well as other patient groups in industrialized countries. HCV subtype 3a infection remains highly prevalent and frequently transmitted in the population of intravenous drug users. The objective of this study was to understand better the mechanisms of the worldwide HCV-3a epidemics in drug users. Ninetythree sera from HCV-3a-infected IDUs from France, the United States, Brazil, Argentina, and Australia were studied. Phylogenetic analyses of the non-structural 5B region showed no specific clustering according to the continent of the patient's origin. Non-exclusive clusters of viral sequences from South America, Australia, and California were observed, but topologies were not supported by strong bootstrap values. The results suggest that HCV-3a has been transmitted from a common origin through a unique worldwide epidemic that rapidly spread among drug users. Regional transmission occurred in the recent past, leading to an embryonic genetic diversification of HCV-3a among local injecting drug user population.
A number of reports have indicated an increased risk of cirrhosis and hepatocellular carcinoma in... more A number of reports have indicated an increased risk of cirrhosis and hepatocellular carcinoma in hepatitis B virus (HBV)-infected individuals carrying HBV e antigen (HBeAg)-negative variants. Although distinct core promoter and precore mutations distributed according to geographical locality and viral genotype have been reported, epidemiological data from South America are still scarce. The prevalences of HBV genotypes and core promoter and precore polymorphisms in 75 HBeAg-negative Argentinean blood donors were surveyed. The observed frequencies of HBV genotypes were 64.0% for genotype F, 17.3% each for genotypes A and D, and 1.3% for genotype C. Genotype F strains were widely distributed and significantly more prevalent in the northern region of the country ( P < 0.001). An overall high proportion of a stop codon mutation (UAG) at precore codon 28 (66.7%) was observed. Wild-type codon 28 (UGG) was present in 29.3% of the samples, and the remaining 4.0% of samples had mixed var...
By using molecular surveillance of hepatitis A virus, we characterized for the first time a subge... more By using molecular surveillance of hepatitis A virus, we characterized for the first time a subgenotype IB imported case in Argentina, a country with universal vaccination since 2005. The case was a crew member of a cruise ship. We consider this a case alert because of its multiple implications.
In this article we discuss the medical diagnoses underlying the most common lawsuits involving pe... more In this article we discuss the medical diagnoses underlying the most common lawsuits involving pediatricians in the United States. Where applicable, specific and general risk-management techniques are noted as a means of increasing patient safety and reducing the risk of medical malpractice exposure.
Exercise stress electrocardiography (ECG) alone is underutilized in part due to poor diagnostic a... more Exercise stress electrocardiography (ECG) alone is underutilized in part due to poor diagnostic accuracy. High-frequency QRS analysis (HF-QRS) is a novel tool to supplement ST evaluation during stress ECG. We compared the diagnostic accuracy and net reclassification of HF-QRS analysis compared with ST evaluation for substantial myocardial ischemia by exercise SPECT myocardial perfusion imaging (MPI). Exercise SPECT MPI was performed in 257 consecutive eligible patients (mean age 59 ± 12, 67% male). An ischemic HF-QRS pattern was defined as a ≥ 1 µV absolute reduction and a ≥ 50% relative reduction of the root-mean-square of the 150-250 Hz band signal in ≥ 3 leads. Left ventricular ischemia of ≥ 10% on SPECT MPI was the diagnostic standard for substantial myocardial ischemia. HF-QRS analysis demonstrated incremental diagnostic value to ST evaluation plus clinical risk factors (AUC 0.804 vs 0.749, P &lt; .0001). A HF-QRS + ST -analysis strategy identified 92.3% of subjects with substantial ischemia and no abnormality in 59.9% of the cohort. No cardiac events occurred in patients without substantial ischemia identified by HF-QRS analysis. In this prospective analysis, exercise stress ECG with HF-QRS analysis identified any and substantial ischemia with high diagnostic accuracy and may allow more than half of referred patients to safely avoid imaging.
This study sought to perform a systematic review and meta-analysis to understand the prognostic v... more This study sought to perform a systematic review and meta-analysis to understand the prognostic value of myocardial scarring as evidenced by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging in patients with known or suspected cardiac sarcoidosis. Although CMR is increasingly used for the diagnosis of cardiac sarcoidosis, the prognostic value of CMR has been less well described in this population. PubMed, Cochrane CENTRAL, and metaRegister of Controlled Trials were searched for CMR studies with ≥1 year of prognostic data. Primary endpoints were all-cause mortality and a composite outcome of arrhythmogenic events (ventricular arrhythmia, implantable cardioverter-defibrillator shock, sudden cardiac death) plus all-cause mortality during follow-up. Summary effect estimates were generated with random-effects modeling. Ten studies were included, involving a total of 760 patients with a mean follow-up of 3.0 ± 1.1 years. Patients had a mean age of 53 years, 41%...
Late versus early acute antibody-mediated rejection (AAMR) or acute cellular rejection (ACR) epis... more Late versus early acute antibody-mediated rejection (AAMR) or acute cellular rejection (ACR) episodes are associated with poorer kidney function and graft survival. We explored whether cell senescence upon detection of AAMR ± ACR contributes to these results. We reviewed the renal transplant database of 2 Institutions. Biopsies performed for acute graft dysfunction from January 2000 to March 2007 were analyzed for morphological criteria of AAMR with or without ACR (n = 17 from 17 patients). Immunoperoxidase staining for p16(INK4B) was performed on the remaining paraffin-embedded tissue in 9 of 17 cases. The average number of positive cells/high power field (HPF) was calculated in every case. Cases with rejection were grouped according to the time of presentation: early (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;3 months n = 8) versus late (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;3 months; n = 9). Graft function was obtained using the Modification of Diet in Renal Disease (mDRD) glomerular filtration rate estimate (eGFR) before, during rejection, and at the last visit, to calculate ΔeGFR. Nuclear expression of p16(INK4B) was 12.2 ± 11.3 cells/HPF in 4 of 8 biopsies performed at a median of 23 (range = 4-80) days (early AAMR ± ACR), and 59.8 ± 51.3 cells/HPF in 5 of 9 biopsies performed at a median of 1171 (range = 279-3210) days (late AAMR ± ACR). eGFR before rejection was 48.5 ± 7.6 mL/min, and 43.7 ± 4.3 mL/min for early and late rejection episodes, respectively (P = not significant [NS]). ΔeGFR of 12.5 ± 25.9 mL/min (early rejection), and -13.7 ± -12.3 mL/min (late rejection), versus last follow-up visit (P = .02) occurred at a median of 143.9 ± 94.1 and 69.6 ± 35.1 weeks after the rejection episodes, respectively. Even though the number of biopsies analyzed for p16(INK4a) was small, it was evident that the number of cells expressing this marker of senescence was higher among biopsy specimens obtained with late rejection episodes. This finding suggests the presence of injuries prior to the rejection episode. The significantly lower eGFR at last follow-up in the late rejection group may translate to a reduced capacity of the repair process to sustain nephron function.
We have examined the structural response of a zinc 2,6-naphthalene dicarboxylate framework solid,... more We have examined the structural response of a zinc 2,6-naphthalene dicarboxylate framework solid, isostructural with MOF-105, to the inclusion during crystallization of dimethylformamide, benzene, toluene, and p-xylene. These compounds, which are made up of a stacked arrangement of four-connected layers, crystallize in the space group P2 1 /c with [Zn 2 (ndc) 2 (DMF) 2 ]‚1.6DMF (1), a) 8.075(1) Å, b) 16.891(2) Å, c) 12.673(2) Å,) 92.90(1)°, [Zn 2 (ndc) 2 (DMF) 2 ]‚C 6 H 6 (2) a) 8.340(2) Å, b) 15.660(4) Å, c) 13.008(4) Å,) 91.340-(5)°, [Zn 2 (ndc) 2 (DMF) 2 ]‚C 7 H 8 (3), a) 8.183(2) Å, b) 16.245(3) Å, c) 12.920(3) Å,) 91.976(4)°, and [Zn 2 (ndc) 2 (DMF) 2 ]‚C 8 H 10 (4), a) 7.973(2) Å, b) 16.946(3) Å, c) 12.922(3) Å,) 92.798(4)°. The structure is found to include p-xylene with high selectivity from mixtures of xylene isomers. In the presence of only o-or m-xylene as an additive, the structure does not crystallize. The mobility of fully deuterated benzene and toluene within compounds 2 and 3 over the temperature ranges 123-294 and 173-294 K, respectively, has been measured by 2 H NMR using the quadrupole echo technique. Benzene is found to execute rapid hopping around its C 6 axis over the entire temperature range studied with an activation energy of 6(1) kJ mol-1. The only motion of the toluene is rapid rotation of the-CD 3 group. Computational modeling of the structures successfully reproduces the crystal structures and the changes in unit cell parameters and indicates that the binding energies of m-xylene within the structure are less favorable than those for p-xylene, predominantly as a result of the distortion of the framework required to accommodate the m-xylene. These lower binding energies explain the high selectivity for the uptake of p-xylene during crystallization.
D-002 is a new natural drug from beeswax with anti-inflammatory and anti-ulcer effects proved in ... more D-002 is a new natural drug from beeswax with anti-inflammatory and anti-ulcer effects proved in different experimental animal models. Pre-clinical toxicology of D-002 showed no drug-related toxicity. The present study was performed to evaluate the effects of D-002 on drug-metabolizing enzymes (Fase I) in male Sprague Dawley rats. The content of P-450 and b5 cytochromes and the activities of the NADPH cytochrome c reductase, aminopyrine N-demethylase, N-dimethylnitrosamine dealkylase, were determined. The biotransformation of benzo(a)pyrene was evaluated by using the Ames test. The results demonstrate that D-002 administered orally at dosis of 50 to 1000 mg/kg/day for one month does not affect the activities of the hepatic drug-metabolizing enzymes investigated. Positive controls treated with phenobarbital and β-naphthoflavone showed significant differences.
In Argentina, a country considered non-endemic for hepatitis E virus (HEV) infection, serologic e... more In Argentina, a country considered non-endemic for hepatitis E virus (HEV) infection, serologic evidence of HEV infection has been observed in different human population groups. In other countries, a high degree of genetic relatedness has been observed between human and swine HEV genotype 3 sequences, suggesting zoonosis as one probable route of infection. This is the first identification of swine HEV in South America. HEV RNA was detected and sequenced in the ORF 1 and ORF 2 regions from swine fecal samples from a herd located in Pergamino, in the province of Buenos Aires. These strains all group into genotype 3 and exhibit a close relationship to two novel HEV variants previously identified in Argentina from sporadic acute cases of non-A to -C hepatitis in humans. In addition, using a modified commercial ELISA, the presence of anti-HEV antibodies was surveyed in five provinces across the country and all five showed a prevalence of HEV antibodies, ranging from 4% to 58%. The results suggest that swine could be an important reservoir for virus transmission in Argentina as has been suggested for other non-endemic areas. The Argentine human strains and swine strain described in this article seem to be closely related to a human Austrian strain, suggesting a potential European origin of HEV infection in these cases.
Current scientific and technological progress has led to the proliferation of e-learning systems ... more Current scientific and technological progress has led to the proliferation of e-learning systems known as Learning Management Systems. These systems consist of a central application for managing the sequencing of students&amp;amp;amp;amp;amp;amp;#x27; tasks, and also on several other educational ...
Here we provide evidence for a critical role of PP2As (protein phosphatase 2As) in the transforma... more Here we provide evidence for a critical role of PP2As (protein phosphatase 2As) in the transformation of Trypanosoma cruzi. In axenic medium at pH 5.0, trypomastigotes rapidly transform into amastigotes, a process blocked by okadaic acid, a potent PP2A inhibitor, at concentrations as low as 0.1 μM. 1-Norokadaone, an inactive okadaic acid analogue, did not affect the transformation. Electron microscopy studies indicated that okadaic acid-treated trypomastigotes had not undergone ultrastructural modifications, reinforcing the idea that PP2A inhibits transformation. Using a microcystin–Sepharose affinity column we purified the native T. cruzi PP2A. The enzyme displayed activity against 32P-labelled phosphorylase a that was inhibited in a dose-dependent manner by okadaic acid. The protein was also submitted to MS and, from the peptides obtained, degenerate primers were used to clone a novel T. cruzi PP2A enzyme by PCR. The isolated gene encodes a protein of 303 amino acids, termed TcPP2...
Pseudolipomatosis is an artifactual microscopic change in tissues that resembles fatty infiltrati... more Pseudolipomatosis is an artifactual microscopic change in tissues that resembles fatty infiltration, most often described in the gastrointestinal tract. The fatlike spaces represent air or gas bubbles that enter the mucosa through microscopic ruptures secondary to gaseous insufflation. We report a series of cases of pseudolipomatosis encountered in gynecologic tissues removed during hysteroscopic procedures, a finding not previously described. We identified 300 consecutive hysteroscopic procedures performed at our institution from 2006 to 2008. Patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; medical records were reviewed to collect pertinent clinical data. Slides from all cases were systematically reviewed. The diagnosis of pseudolipomatosis was established by consensus. Twenty-eight cases of pseudolipomatosis, representing 9.3% of patients who under went hysteroscopy, were identified. Pseudolipomatosis was found in 9 endometrial curettings or biopsy tissues, 8 endometrial or endocervical polyps, 8 uterine fibroids, 2 fallopian tubes, and 1 endocervical biopsy. The type of distention medium used and length of hysteroscopic procedure did not differ significantly between cases with and without pseudolipomatosis. Pseudolipomatosis vacuoles varied in distribution from crowded clusters to sparsely scattered and solitary. Occasionally, vacuoles were found in vascular channels. Vacuoles were round or ovoid, unilocular, and variable in size. Immunohistochemical staining for adipocyte and endothelial markers were negative. We hypothesize that pseudolipomatosis derives from air that is almost invariably introduced into the uterus during media insufflation for hysteroscopy, creating a bubble under pressure. The air enters tissues either through lining microruptures or during the biopsy procedure. Pseudolipomatosis is a relatively common, easily overlooked finding in hysteroscopically derived specimens that may be misdiagnosed when prominent.
This paper presents a model of cross-cultural negotiations which describes how the affect negotia... more This paper presents a model of cross-cultural negotiations which describes how the affect negotiators experience during negotiations influences the character of the negotiation process and its outcomes. Three categories of determinants of negotiator affect are proposed: Individual differences, cross-cultural differences, and contextual factors. The ways in which negotiator affect influences information processing during negotiations are then described. It is suggested
Study objective: To evaluate the e~l~ectiveness of two teaching interventions to increase residen... more Study objective: To evaluate the e~l~ectiveness of two teaching interventions to increase residents' performance of smoking cessation counseling. Design: Randomized controlled factorial trial Setting: Eleven residency programs, in internal medicine (six), family medicine (three), and pediatrics (two). Pro. grams were located in three university medical centers and four university-affdiated community hospitals. Participants: 261 residents who saw ambulatory care patlents at least one half-day per week, and 937 returning patients aged 17 to 75years who reported having smoked five or more cigarettes in the preceding seven days. Of the 937, 843 were eligible for follow-up, and 659 (78%) were interviewed by phone at six months. Interventions: Two interventions (tutorial and prompt) and four groups. The tutorial was a two-hour educational program in minimal-contact smoking cessation counselingfor residents. The prompt was a chart-based reminder to assist physician counseling. One group of residents received the tutorial,, one, the prompt; and one, both. A fourth group received no intervention.
To determine mammography use among women with a broad range of ages, the authors surveyed women a... more To determine mammography use among women with a broad range of ages, the authors surveyed women aged 30 to 74 years and physicians practicing primary care in two eastern North Carolina counties. Twenty-five percent of women in their 30s had ever had a mammogram, and 34% intended to have one in the coming year. From 45% to 52% of women in their 40s, 50s, and 60s had ever had a mammogram, and 55% to 57% intended to have one in the next year. Thirty-seven percent of women aged 70 to 74 years had ever had a mammogram, and 40% intended to have one in the following year. Nineteen percent of physicians reported screening nearly all women aged 30 to 39 years, and 14% screened few women aged 50 to 74 years. Younger women were more worried about breast cancer than older women and assessed their risk as higher, attitudes that were generally associated with higher mammography utilization. These community surveys suggest that mammography use may be excessive among younger women; older women continue to be underscreened.
A method is described for genotyping of hepatitis B virus (HBV), based on the restriction fragmen... more A method is described for genotyping of hepatitis B virus (HBV), based on the restriction fragment length polymorphism (RFLP) created by Ava2 and Dpn2 action on an amplified segment of the pre-S region. Analysing 51 database sequences by phylogenetic tree construction and RFLP prediction, the method was shown to be capable of detecting all known genotypes (A-F). The method was applied to 99 serum samples from hepatitis B e antigen (HBeAg)-positive chronic carriers, comparing observed agarose gel patterns with the RFLP predicted from the database sequences. In 95 typable samples the following genotypes were observed; 23 A, 20 B, 20 C, 22 D, 5 E and 5 F. Phylogenetic grouping of the 51 database sequences and RFLP genotyping of the 99 patient samples were compared with typing based on S gene analysis, showing disagreement in only one case, a database sequence of ayw subtype which was classified as genotype D by pre-S region and genotype A by S region analysis. This method should be useful for epidemiological investigations and for studying the potential influence of genotype on the course of infection.
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Papers by Jorge Gonzalez