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Biomedical subjects

M Cohen

Publications and source records attributed to M Cohen.

At least 343 records · Page 19Linked to original sources
PubMed1997

The additional value of free prostate specific antigen to the battery of age-dependent prostate-specific antigen, prostate-specific antigen density and velocity.

This study describes the value of using the fraction of free prostate-specific antigen as a further marker in the early detection of prostate cancer. This newly introduced marker is compared to the usual battery of age-dependent total prostate-specific antigen, prostate-specific antigen density (microg/l x g tissue) and prostate-specific antigen velocity (microg/l x year). Determination of total prostate-specific antigen and free prostate-specific antigen was performed on fresh serum samples obtained from 3470 symptomatic patients aged 45-80 attending the Urology Clinics, or their General Practitioners. Among them, 310 patients had total prostate-specific antigen above the age-dependent cut-off, and/or free/total prostate-specific antigen under 11%, with different prostate-specific antigen densities and velocities. Only 147 patients complied to undergo biopsy: in 72 of those patients, benign prostatic disease was histologically confirmed, while in 75 patients primary prostate cancer was histologically confirmed. Total and free prostate-specific antigen levels were determined using the third generation DPCs prostate-specific antigen assay performed on the Immulite automated immunoassay instrument. Total prostate-specific antigen age reference values were adopted from Oesterling et al. (J Am Med Ass 1993; 270:860-4); the prostate-specific antigen density was considered suspicious of prostate cancer if it was greater than 0.15 microg/l prostate-specific antigen per gram tissue (Seaman et al. Urol Clin N Am 1993; 20:653); prostate-specific antigen velocity greater than 0.75 microg/l x year (Carter et al., J Am Med Ass 1992; 267:215) was considered suspicious for prostate cancer. Of the 147 patients, 75 had prostate cancer and 72 had benign prostatic hypertrophy. The difference between prostate cancer and benign prostatic hypertrophy was significantly reflected only by free/total prostate-specific antigen and prostate-specific antigen velocity. These parameters also provided the best sensitivity and specificity. Only these parameters proved to be significant when using a backwards logistic regression model (prostate-specific antigen velocity, p = 0.007 odds ratio 2.782; free/total prostate-specific antigen %, p = 0.016 odds ratio 2.678). Combinations of various parameters became significant when including free/total prostate-specific antigen, increasing prostate cancer detection to 88%. We conclude that free/total prostate-specific antigen is the most significant among prostate-specific antigen quantities (total age-dependent prostate-specific antigen, prostate-specific antigen density and prostate-specific antigen velocity). Adding this parameter to other prostate-specific antigen parameters improves the discrimination between prostate cancer and benign prostatic hypertrophy for the population at risk.

Aged↗
PubMed1997

Detection of a 22q11.2 deletion in cardiac patients suggests a risk for velopharyngeal incompetence.

OBJECTIVE: Conotruncal cardiac anomalies frequently occur in patients with DiGeorge or velocardiofacial syndrome. Additionally, these patients may have overt or submucousal cleft palate, as well as velopharyngeal incompetence (VPI). Previous studies have demonstrated that the majority of these patients have a submicroscopic deletion of chromosome 22q11.2. We hypothesized that a subpopulation of newborns and children with congenital heart defects caused by a 22q11.2 deletion are at a high risk for having unrecognized palatal abnormalities. Therefore, we proposed to evaluate a cohort of patients with conotruncal cardiac malformations associated with a 22q11.2 deletion to determine the frequency of palatal abnormalities. METHODS: We identified 14 deletion-positive patients with congenital cardiac defects who had no overt cleft palate. Of the 14 patients evaluated for the 22q11.2 deletion, 8 patients were recruited from a previous study looking for deletions among patients with isolated conotruncal cardiac anomalies. Informed consent was obtained in these cases. The remaining patients had the deletion study on a clinical basis, ie, conotruncal cardiac defect and an absent thymus, immunodeficiency, or minor dysmorphia appreciated by the clinical geneticist. These patients were evaluated by a plastic surgeon and speech pathologist looking for more subtle palatal anomalies such as a submucousal cleft palate, absence of the musculous uvuli, and VPI. Some patients underwent videofluoroscopy or nasendoscopy depending on their degree of symptoms and age. VPI was not ruled out until objective evaluation by a speech pathologist and plastic surgeon was obtained. In addition, the child had to be old enough to provide an adequate speech sample. RESULTS: Of the 14 patients evaluated, 6 patients older than 1 year were found to have VPI. It is noteworthy that 3 of these patients were older than 5 years and had remained unrecognized until this study. The remaining 6 patients had inconclusive studies based on their age (younger than 26 months) and their inability to participate in adequate speech evaluations. Two of these patients, however, had histories of nasal regurgitation suggesting VPI and, in addition, had incomplete closure of the velopharyngeal mechanism during crying and swallowing observed during nasendoscopic examination-consistent with the diagnosis of VPI. Thus, 8 of 14 patients evaluated had evidence of VPI by history and examination. The remaining 6 patients will require further study when they are older before a definitive palatal diagnosis can be made. CONCLUSIONS: A significant number of patients with a 22q11.2 deletion in a cardiac clinic may have unrecognized palatal problems. Recognition of such abnormalities will afford patients the opportunity for intervention as needed, ie, speech therapy and/or surgical intervention. Notably, two of our patients with findings suggesting VPI were infants and will, therefore, be afforded the opportunity for close follow-up and early intervention. Furthermore, three school-aged children had palatal abnormalities that were unrecognized until this study. Thus, we recommend 22q11.2 deletion studies in patients with conotruncal cardiac malformations, followed by extensive palatal and speech evaluations when a deletion is present.

Abnormalities, Multiple↗
PubMed1997

Macrovascular disease is associated with increased plasma apolipoprotein A-IV levels in NIDDM.

Apolipoprotein A-IV (apoA-IV) might play an important role in lipoprotein metabolism, including modulation of triglyceride-rich lipoprotein catabolism, reverse cholesterol transport and cholesteryl ester transfer protein (CETP) activity. Increased apoA-IV levels have been reported in plasma from NIDDM patients. The aim of the present study was to look for a possible association between plasma apoA-IV level and prevalence of macrovascular disease in NIDDM. One hundred and thirty-six NIDDM patients were studied (71 men, 65 women). Macrovascular disease was assessed in each patient by a standardized questionnaire, physical examination, resting electrocardiogram (ECG), and laboratory evaluation (ankle/arm blood pressure ratio, continuous wave Doppler velocimetry). Moreover, patients without any history of coronary heart disease and showing a normal resting ECG underwent a bicycle exercise test or a dipyridamole thallium scintigraphy to detect possible silent myocardial ischemia. Among the 136 NIDDM patients, 56 had macrovascular disease. ApoA-IV levels were significantly higher in NIDDM patients with macrovascular disease than in NIDDM patients without macrovascular disease (20.9 +/- 8.6 vs. 13.3 +/- 5.3 mg/dl; P < 0.001). The influence of different factors, such as age, BMI, cigarette smoking, hypertension, total cholesterol, triglycerides, HDL cholesterol, apoA-IV level, apoA-IV phenotype, fasting glycemia, fasting C-peptide, and microalbuminuria, on the prevalence of macrovascular disease was analyzed using a logistic regression model. In the univariate analysis, apoA-IV level (P < 0.00001), age (P = 0.0087), hypertension (P = 0.012), microalbuminuria (P = 0.018), triglycerides (P = 0.02), and fasting C-peptide (P = 0.03) were positively associated with macrovascular disease. In the multivariate analysis, macrovascular disease was positively associated only with apoA-IV (P < 0.0001) and age (P = 0.003) and negatively associated with HDL cholesterol (P = 0.013). These results indicate that increased plasma apoA-IV level is associated with an increased prevalence of macrovascular disease in NIDDM. Moreover, apoA-IV, in NIDDM patients, appears to be a better marker for macrovascular disease than triglycerides.

Apolipoproteins A↗
PubMed1997

Abnormal audiograms and elevated acoustic reflex thresholds in obligate carriers of autosomal recessive non-syndromic hearing loss.

Pure-tone audiograms and acoustic reflex thresholds were obtained in 24 presumed obligate carriers of autosomal recessive non-syndromic hearing loss and 30 sex and age appropriate control subjects, with a view to evaluating the prevalence of abnormalities on these tests in the two groups, and a possible link between the findings on the two tests, which may help to localize threshold deficits and/or abnormal configurations to different sections of the reflex arc. Six (25%) of the carriers and one control subject had abnormal audiograms, inferred to be of genetic aetiology through careful exclusion of environmental risk factors. Four additional carriers had acoustic reflex threshold abnormalities. None of the carriers had an abnormality on both tests. The audiometric configurations and acoustic reflex patterns of abnormality were diverse, and may be a reflection of the genetic heterogeneity in ARNSHL.

Adult↗
PubMed1997

Acupuncture needles and the Seebeck effect: do temperature gradients produce electrostimulation?

Acupuncture may act through modifying bioelectric events and this may occur through different mechanisms including the application of external currents. According to the Seebeck effect which produces a potential difference when a temperature gradient is placed across a conductor, the physical properties of acupuncture needles may produce internal currents due to the temperature gradient across the needle when placed insitu. Such currents were detected when needles were differentially heated and these currents were found to be in the range capable of producing biological effects. The traditional design of acupuncture needles and traditional needle manipulations seem to maintain a temperature gradient across the needle and thus enhance the Seebeck effect.

Acupuncture Therapy↗
PubMed1997

Materials used in urological devices.

The most commonly used materials in the manufacture of urological devices are discussed with respect to their application to urinary catheters, penile implants, testicular implants, artificial urinary sphincters, and urological stents. The manufacturing, physical properties, and general chemical and biological behavior of there materials are reviewed. Attention is paid to future research trends and the general condition of the field of urological device materials.

Biocompatible Materials↗
PubMed1997

Cost implications of selective preoperative risk screening in the care of candidates for peripheral vascular operations.

The preoperative identification that patients are at high risk for adverse postoperative outcomes is the first step toward preventing costly in-hospital complications. The economic implications of noninvasive screening strategies in the care of patients undergoing peripheral vascular operations must be clarified. A decision model was developed from the peer-reviewed literature on patients undergoing preoperative screening by means of dipyridamole myocardial perfusion imaging, dobutamine echocardiography, or cardiac catheterization before vascular operations (n = 23 studies). Routine versus selective screening strategies were compared for patients with an intermediate likelihood of having coronary artery disease on the basis of clinical history of coronary disease or typical symptoms. Median costs (1994 US dollars) of preoperative screening strategies were derived with two microcosting approaches: adjusted Medicare charges (top-down approach) and a bottom-up approach with Duke University Center direct cost estimate data. In-hospital cost was 11% higher for preoperative screening by means of routine cardiac catheterization ($27,760) than for routine pharmacologic stress imaging ($24,826, P = 0.001). The total cost of a do-nothing strategy, that is, no preoperative testing, was 5.9% less than that of routine preoperative pharmacologic stress imaging and 15.9% lower than that of cardiac catheterization (P = 0.001). Selective screening among patients with a history of coronary disease or typical angina resulted in further reduction of the cost of care to a level comparable with that of a do-nothing strategy (52.5% reduction in cost with pharmacologic stress imaging, P > 0.20). Use of noninvasive testing for preoperative risk stratification was cost effective for patients 60 to 80 years of age. Cost per life saved ranged from $33,338 to $21,790. However, coronary revascularization after an abnormal noninvasive test was cost effective only for patients older than 70 years. In this economic decision model, substantial cost savings were predicted when selective noninvasive stress imaging was added to preoperative screening for patients about to undergo vascular operations. With a selective screening approach, the economic impact of initial diagnostic testing may be minimized without compromising patient outcomes.

Decision Trees↗
PubMed1997

Imaging of acute injuries to the wrist and hand.

This article reviews the basic characteristics of common fractures and dislocations in the hand and wrist. There is increasing recognition that fractures and dislocations of the hand and wrist can result in long-term pain and dysfunction. This article includes descriptions and, when helpful, classifications for these fractures with attention to those features that are of prognostic and therapeutic significance. With prompt recognition and proper characterization of these injuries, patients can be triaged to the orthopedic surgeon for early and more aggressive treatment.

Acute Disease↗
PubMed1997

Tissue and differentiation specific expression on the endogenous retrovirus ERV3 (HERV-R) in normal human tissues and during induced monocytic differentiation in the U-937 cell line.

ERV3 (HERV-R) is a complete, single copy human endogenous retrovirus located on the long arm of chromosome 7. The open reading frame in its envelope gene has been conserved during evolution but the gag and pol genes contain in-frame termination codons. To find a suitable experimental model system for analysis of the functions of the ERV3 genome, an extensive screening study of different normal and neoplastic human tissues was performed. Most tissues express low levels of the ERV3 env mRNA although high expression levels are observed in placenta, sebaceous glands, adrenals, testis, bronchial, epithelium and the monocytic cell line U-937. In U-937 cells the ERV3 env expression varied in a manner related to the differentiation status of the cells; being highest in the terminally differentiated non proliferating cells. U-937 cells can be induced to differentiate from the monoblastic to the mature monocyte/macrophage stage upon stimulation by several substances such as phorbolesters (TPA), Vitamin D3, Retinoic Acid (RA) and combinations of some cytokines. We conclude that the ERV3 locus is expressed in a tissue and differentiation specific way and that the U-937 cell line is a suitable model system to further analyze the proposed functions of ERVs such as immunomodulation, cell fusion and protection against exogenous retroviral infections.

Cell Differentiation↗
PubMed1997

[Stroke therapy in children].

OBJECTIVE: To evaluate the treatment modalities used in children (ages 1-18 years) with cerebral infarction. BACKGROUND: [corrected] Cerebrovascular disease in children is more common than once suspected but its treatment has not been rigorously studied. MATERIAL AND METHODS: We reviewed all cases of cerebral infarction at the James Whitcomb Riley Hospital for Children at the Indiana University Medical Center from 01.01.80 to 31.12.95. RESULTS: Ninety-three children who experienced ischemic strokes were followed over the past fifteen years. Fifty-seven males and thirty-six females comprised the sample. Mean age was 6.9 years at the time of stroke. No medication or surgical intervention was the therapeutic recommendation in 44% of patients. For cardioembolic strokes, warfarin was used later in the course for a few patients who went on to have atrial fibrillation or valve replacement. Aspirin was used in all patients with carotid artery dissections. Aspirin was used in most children with Moya-Moya, with calcium channel blockers and surgical intervention used in later cases. Exchange transfusion followed by monthly transfusion and chelation therapy has been the treatment of choice for children with cerebral infarction complicating sickle cell disease. CONCLUSIONS: In most instances, treatment was widely disparate, probably reflecting the lack of firm therapeutic guidelines for this age group, with a better understanding of the etiology and pathophysiology of strokes in children, multicenter, international, randomized therapeutic trials based strictly on an etiological basis should be organized in the future.

Adolescent↗
PubMed1997

[Study of myocardial viability after myocardial infarction. Value and limits of magnetic resonance imaging compared with myocardial scintigraphy].

The aim of this study was to compare myocardial thickness measured by magnetic resonance imaging and quantified fixation of thallium. Twenty-one patients 61.2 +/- 11 years were investigated after myocardial infarction of the anterior wall in 8 cases, inferior in 10 cases, lateral in 2 cases and apical in one case. The mean angiographic ejection fraction was 46.5 +/- 19%. Myocardial scintigraphy was performed after an exercise or pharmacological stress test and followed by a study of redistribution. The data was analysed by a quantitative method. Magnetic resonance imaging was performed with vertical and horizontal long axis views in systole and diastole with division of the left ventricle into the same 12 regions. Three groups were defined according to fixation during redistribution. Group I: regions with fixation > 80% (n = 155); group II: 60 to 80% (n = 78); group III: fixation < 60% (n = 19). All measurement of myocardial thickness were correlated (p < 0.01) with the fixation of thallium during redistribution. Systolic thickening, was significantly greater in group I (3.80 +/- 3.1 mm) than in groups II (2.20 +/- 3.8 mm) and III (1.56 +/- 2.4 mm) in which it was comparable. Regions in group III had systolic (8.61 +/- 3.53) and diastolic (6.89 +/- 3.3 mm) thicknesses significantly inferior to those in groups I (13.79 +/- 4.4 mm: 9.95 +/- 2.8 mm) and II (11.59 +/- 5.5 mm: 9.38 +/- 2.9 mm). Ninety per cent of regions with a systolic thickness of over 10 mm had fixation during redistribution of more than 60%. This study shows that myocardial thickness is correlated to scintigraphic data. The systolic thickness over 10 mm would confirm the viability of a given region.

Adult↗
PubMed1997

Closed and restricted practices.

OBJECTIVE: To determine the proportion of recently certificated Ontario family physicians who have closed their practices to new patients or restricted their services. DESIGN: Cross-sectional survey mailed between September 1993 and January 1994. SETTING: Ontario family practices. PARTICIPANTS: All family medicine residency-trained certificants of the College of Family Physicians of Canada from 1989 to 1991 currently practising in Ontario. Response rate was 70% (395 of 564 eligible physicians). Otherwise eligible physicians practising as locums, emergency room physicians, or military physicians were excluded. MAIN OUTCOME MEASURES: Self-report of practices being closed to new patients and of various restrictions placed on practices. RESULTS: Nearly one third of respondents had closed their practices to new patients. Although the decision to close a practice correlated with length of time in practice, physicians in metropolitan Toronto were significantly less likely to report closed practices than physicians practising in other regions of Ontario. Restrictions reported related to patients and problems, geographic area, and type of setting(s) serviced. About 45% of respondents did not provide one or more of a defined set of five services. CONCLUSIONS: Results of this study suggest that family physicians restrict their practices in various ways within the first 5 years after certification.

Certification↗
PubMed1997

[Clinico-endoscopic spectrum of gastritis associated with Helicobacter pylori in pediatrics].

In order to gain further knowledge about the clinical and endoscopic features of chronic gastritis (CG) associated with Helicobacter pylori (H py) we retrospectively analyzed 81 pediatric cases. All were biopsy-proven. The cases were divided in two groups: Group (1988-1992) included 21 cases. These represented the early stage of clinical recognition of the disease. Group 2(1993-1995) comprised 60 cases and represents the stage in which the disease was mandatory. Mean number of cases/year was 4.2 and 20 for group 1 and 2, respectively. Recurrent abdominal pain (RAP) was the most frequent clinical symptom (74/81; 91%), followed by upper digestive tract hemorrhage (UDTG) (34/81; 41.9%). The combination gastroesophageal reflux (GER) and esophagitis (E) was found in 52/81 (64.2%) of the children. Endoscopically, granularity of the mucosa was more frequently found in cases with RAP (47/74), GER (28/36) and E, while a smooth mucosa predominated in patients with UDTH (23/34). Our findings strongly suggest that symptomatic CG with H py in children expresses peculiar clinical and endoscopic features. Since RAP was present in 91% of the cases it appears adequate to include this disease in the differential diagnosis of it. These clinical manifestations have not been previously linked to CG with H py. Better understanding of the clinical and endoscopic spectrum of CG with H py results in adequate treatments and possibly prevention of gastric (and esophageal) diseases found in adults.

Abdominal Pain↗
PubMed1997

[Mass screening programs for breast cancer in France. Comparative evaluation].

OBJECTIVE: The purpose of this work was to comparatively assess the results of mass screening programs for breast cancer implemented in six French departments in 1986, within the scope of the National Fund for Health Prevention, Education and Information of the National Health Insurance Office of Salaried Workers. MATERIAL AND METHODS: The data collected by the screening centres were analyzed by ten assessment teams that were independent from the program promotion staff, all using the same evaluation form. A complementary population study performed in eight French districts then, allowed assessing the frequency of self-referred screening (mammography performed out of program). RESULTS: The rate of participation in screening programs, in relation to the invited population, ranged from 21 to 48%, according to the district (36% in average). This low participation was probably related to the extent of self-referred screening. In fact, 19 to 40% of women, according to the district, had previously had a screening mammographic coverage: rate was around 68% in women aged 50 to 69 years. Positive findings with mammography ranged from 4.5 to 15.8% (10.1% in average), while intervention rates ranged from 0.7 to 1.6% and detection rates from 3.8 to 6.2%. The ratio between benign tumors and cancers ranged from 0.7 to 2.1 according to the district. In order to enlighten the judgement on French results, we propose a comparison with the international standards in force. CONCLUSION: The various experiences with breast cancer screening in France show that this screening is technically feasible on the basis of existing medical structures. However, some criteria are still below the expected values, especially if compared with international standards. This result is probably accounted for by the high rate self-referred screening before age 40 in France. In these conditions, the question is whether extending breast cancer screening programs in France is an appropriate course of action.

Breast Neoplasms↗
PubMed1997

Heart transplantation with bicaval and pulmonary venous anastomoses. A hemodynamic analysis of the first 117 patients.

BACKGROUND: A new surgical technique for orthotopic heart transplantation has been introduced into clinical practice. It accomplishes total atrioventricular transplantation as the recipient's atria are completely excised and the allograft is implanted using bicaval and pulmonary venous anastomoses. MATERIALS AND METHODS: We retrospectively analyzed post-transplant hemodynamic and patient survival in our first 117 patients transplanted with this new operative approach and compared them with 64 patients transplanted with the standard biatrial technique. RESULTS: Patients transplanted with the bicaval technique had a significantly lower right atrial mean, pulmonary arterial systolic, pulmonary arterial mean, and pulmonary capillary wedge pressures. In addition, a significant reduction in post-transplant tricuspid regurgitation and a trend towards less severe mitral regurgitation was observed. The need for permanent pacemaker implantation due to sinus node dysfunction after transplantation was completely eliminated with this new technique. Thirty-day operative survival and actuarial survival at 1, 2, 3, and 4 years was significantly greater in patients transplanted with the bicaval technique. CONCLUSIONS: Orthotopic heart transplantation performed with bicaval and pulmonary venous anastomoses offers improved post-transplant hemodynamics, eliminates the need for permanent pacemaker, and has improved patient survival when compared with the standard biatrial technique. These differences can be related in part to improved hemodynamic function of the cardiac allograft due to preservation of the anatomic configuration and physiologic function of the atria.

Adult↗
PubMed1997

[Creutzfeldt-Jakob disease and pregnancy].

Recent public health concern about the Jacob-Creutzfeld disease related to administration of growth hormone in children or the "mad cow" disease in cattle fed contaminated products requires a review of the association between Jacob-Creutzfeldt disease and pregnancy. Four cases of this transmissible spongiform encephalopathy have been described in pregnant women and none of the offspring, currently 22, 10, 7 and 3 years of age, have developed the disease. Vertical transmission of Jacob-Creutzfeldt disease cannot however be excluded as it occurs in animals and since injections of cord blood and placenta extracts of women with this disease into mice brains has proven the presence of the infectious agent. The rarity of Jacob-Creutzfeldt disease in women of reproductive age and the particularly long incubation period of this type of encephalopathy would incite prudence and long-term follow-up to determine outcome in children born from disease women or who developed signs of the disease during the years following delivery.

Animals↗