Biomedical subjects

Lawrence Cohen

Publications and source records attributed to Lawrence Cohen.

11 recordsLinked to original sources

PubMed2006

Clinical recommendations for the use of recombinant human erythropoietin in patients with hepatitis C virus being treated with ribavirin.

Today, combination antiviral therapy with pegylated interferon-alpha and ribavirin (RBV) allows many patients infected with hepatitis C virus (HCV) to achieve a sustained virological response, which is equivalent to cure. Data also support the clinical benefit of combination antiviral therapy in patients coinfected with HCV and HIV, and in patients who have received a liver transplant. Antiviral therapy with pegylated interferon-alpha and RBV is, however, associated with a high incidence and significant magnitude of anemia. This anemia may have several mechanisms, including bone marrow suppression and hemolysis. In addition, patients coinfected with HIV may have both pre-existing and RBV-associated anemia. Management of anemia in patients with HCV through RBV dose reduction or treatment discontinuation may compromise the effectiveness of treatment, because studies have demonstrated that treatment adherence or maintenance of antiviral therapy dose is an important predictor of sustained virological response. Anemia associated with combination antiviral therapy in patients with HCV is frequently associated with an inadequate or blunted endogenous erythropoietin response. Accumulating evidence now supports the use of recombinant human erythropoietin (rHuEpo) to manage anemia in these patients, with the objective of maintaining the RBV dose, but clinical standards are lacking. The present article reviews the data relevant to the use of rHuEpo in this patient population and proposes a set of clinical practice standards to assist clinicians in selecting patients for rHuEpo and in implementing rHuEpo therapy effectively.

Algorithms↗

PubMed2003

Absence of symptomatic benefit of lansoprazole, clarithromycin, and amoxicillin triple therapy in eradication of Helicobacter pylori positive, functional (nonulcer) dyspepsia.

OBJECTIVES: The aim of this study was to compare the effect of a combination of lansoprazole, clarithromycin, and amoxicillin (LCA) versus placebo on the severity of symptoms in functional dyspepsia patients who were positive for Helicobacter pylori (H. pylori). METHODS: This was a double-blind, randomized, controlled clinical trial in adult patients with functional dyspepsia who were H. pylori positive. Patients were randomized to 7-day treatment with LCA or identical looking placebo. H. pylori status was confirmed by the urea breath test performed at baseline, at 6 wk, and at 6 and 12 months. The severity of eight upper GI symptoms was measured on a five-point Likert scale. The main outcomes were the change in average severity of the dyspepsia summary score of the eight symptoms and the proportion of patients who improved >/=4 points on the dyspepsia summary score. RESULTS: A total of 157 patients were included in the intention-to-treat analysis. LCA achieved cure of H. pylori infection in 82% of patients compared to 6% in the placebo group. The severity of dyspepsia symptoms improved over the 12-month study period, but for none of the outcome measures was there a significant difference between LCA and placebo. CONCLUSIONS: There was no difference in sustained improvement of dyspepsia symptoms when LCA was compared with placebo. An 82% cure rate of H. pylori infection was observed with LAC.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMed2002

Familial aggregation of diabetes and hypertension in a case-control study of colorectal neoplasia.

Familial aggregation of diseases potentially associated with metabolic syndrome (diabetes mellitus, hypertension, and cardiovascular diseases) was assessed in a colonoscopy-based case-control study of colorectal neoplasia in Toronto and Ottawa, Canada, in 1993-1996. Each familial disease was analyzed by logistic regression using generalized estimating equations. Case probands had incident adenomatous polyps (n = 172) or incident (n = 25) or prevalent (n = 132) colorectal cancer (CRC), while control probands (n = 282) had a negative colonoscopy and no history of CRC or polyps. Significant effect modification was evident in the data, with the strongest positive associations between familial diabetes and colorectal neoplasia among older probands with symptoms (parents: odds ratio (OR) = 2.4, 95% confidence interval (CI): 1.2, 4.8; siblings: OR = 5.8, 95% CI: 2.6, 13.3). Familial hypertension was also associated with colorectal neoplasia among probands with symptoms (OR = 1.7, 95% CI: 1.1, 2.6). In stratified analyses, familial diabetes, hypertension, and stroke were positively associated with adenomatous polyps in subgroups of probands who were older and/or had symptoms, while only familial diabetes was possibly associated with CRC. Associations in other proband groups may have been obscured by high cumulative incidence of parental CRC. Family studies are needed to understand the contribution of specific environmental and genetic factors in accounting for the disease aggregations.

Adult↗

PubMed2002

Threshold, comfortable level and impedance changes as a function of electrode-modiolar distance.

OBJECTIVE: The study investigated the hypothesis that threshold and comfortable levels recorded from cochlear implant patients would reduce, and dynamic range increase, as distance of the electrode from the modiolar wall (radial distance) decreases. Two groups of cochlear implant patients participated; one group using the Nucleus' 24 Contour electrode array, and one group using the Nucleus standard straight (banded) array. The Nucleus 24 Contour array has been shown in temporal bone studies to lie closer to the modiolus than the banded array. The relationship of electrode impedance and radial distance is also investigated. DESIGN: The study, conducted at three centers, evaluated 21 patients using the Contour array, and 36 patients using the banded array. For each patient, threshold, comfortable levels and dynamic range were measured at four time points. Common ground electrode impedance was recorded clinically from each patient, at time intervals up to 12 wk. An estimate of the radial distance of the electrode from the modiolus was made by analysis of Cochlear view x-rays. RESULTS: Threshold and comfortable levels were significantly lower for the Nucleus 24 Contour array than for the banded array. However, dynamic range measurements did not show the predicted increase. In a majority of subjects, a significant correlation was found between the estimated radial distance of the electrode from the modiolus and the measured threshold and comfortable levels. This trend was not observed for dynamic range. The analysis indicates that other factors than radial distance are involved in the resultant psychophysical levels. Clinical impedance measures (common ground) were found to be significantly higher for the Contour array. However, the electrodes on the Contour array are half-rings, which are approximately only half the geometric size of the full rings as electrodes of the standard array. When the geometric electrode area in the two array designs are normalized, the trends in the electrode impedance behavior are similar. CONCLUSIONS: The results support the hypothesis that the relationship between the radial distance of the electrode and the psychophysical measures are influenced by patterns of fibrous tissue growth and individual patient differences, such as etiology and neural survival. Impedance measures for the Nucleus 24 Contour electrode array were higher than the banded electrode array, but this is primarily due to the reduction in electrode surface area. The different outcomes in impedance over time suggest differences in the relative contributions of the components of impedance with the two arrays.

Acoustic Impedance Tests↗

PubMed1999

Where it hurts: Indian material for an ethics of organ transplantation.

Explore the source record for details and available documents.

Anthropology↗

PubMedDate not supplied

Effects of insertion depth of cochlear implant electrodes upon speech perception.

OBJECTIVE: To investigate whether the insertion depth of a cochlear implant array affects postoperative speech perception. DESIGN: The subjects were 48 postlingually deaf adults who received either the Nucleus 22 or the Nucleus 24 cochlear implant with a straight array. A postoperative radiograph of the cochlear electrode was used to estimate insertion depth, as either the angle of the electrode tip (angle) or the intracochlear length of the electrode (length). Other estimates of insertion depth included the numbers of active electrodes and channels used by the speech processor. Electrode depth, together with the duration of deafness, hearing aid usage, pre-operative speech perception score and pre-operative pure-tone averages were independent variables in a forward stepwise multiple regression analysis, where the dependent variables were postoperative CNC words and CNC phonemes. RESULTS: Duration of deafness and insertion depth (angle, insertion length or active electrodes) were the predictive variables for CNC words or CNC phonemes. Angle was the best 'depth-related' predictor of postoperative speech perception. An even clearer relationship was found between CUNY sentences in noise and angle, in a subset of 26 patients. CONCLUSION: Depth of electrode insertion affects postoperative speech perception.

Adult↗

PubMedDate not supplied