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Biomedical subjects

M Cohen

Publications and source records attributed to M Cohen.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Tendons: traumatic lesions].

In the recent years there has been an increase in the number of tendon tears (TT) seen in routine daily outpatient practice secondary to the increasing popularity of sport activities. Tears require early diagnosis to ensure proper treatment and reduce functional impairment. Since local pain, edema and reflex muscle contraction can significantly limit the usefulness of clinical examination, imaging is usually required to confirm the clinical diagnosis, differentiate between partial and complete tear, and localize the retracted tendon stump. Several imaging modalities can be used in the evaluation of TT. Ultrasound is an efficient, dynamic, low cost and non invasive modality that is being increasingly utilized in the evaluation of the musculoskeletal system. It is well accepted by the acutely injured patient. The aim of this review article is to describe the ultrasound findings of the most common tendon tears.

Ankle Joint↗
PubMed2005

[Technical R & D and future applications].

Medical imaging is closely related to technological progress. During the last twenty years considerable progress enabled sonography to assess musculoskeletal structures more and more accurately. Development of new high frequency transducers, harmonic imaging, Doppler sonography and contrast agents resulted in better image quality and increased diagnostic accuracy. Nevertheless, future technologies may provide new additional functional and qualitative possibilities. The limitations of musculoskeletal sonography are rather well established. Some are probably due to physical "obstacles" that future technology could resolve. Elastography and heterogeneous tissues focalisation are examples of experimental applications which could push back the limits of our current practice. But the future of sonography cannot be reduced to a purely technological dimension. It also depends on clinical and paraclinical evaluation as well as on widely available education programs directed to promote a wider diffusion and improved clinical use of sonography.

Biomedical Research↗
PubMed2005

The lack of a simple relation between physician's percutaneous coronary intervention volume and outcomes in the era of coronary stenting: a two-centre experience.

The 2001 ACC/AHA guidelines recommend that percutaneous coronary intervention (PCI) operators perform at least 75 procedures per year to maintain their competency. We performed a post hoc analysis of prospectively gathered PCI data, in the current era of ubiquitous stent use, at two tertiary cardiac care centres. Operators were assigned to a low (<50 cases per year), intermediate (50-74 cases per year) or high volume (>or=75 cases per year) group. Complications evaluated were death, myocardial infarction, coronary perforation, emergent coronary artery bypass surgery and pericardial tamponade. Between 2000 and 2002, 51 operators performed 6,510 PCIs. Stents were used in 79% of cases. Major complications occurred in 0.45% (7/1,572 cases) for the low-volume group, 1.1% in the intermediate-volume group (16/1,438 cases) and 0.86% (30/3,500 cases) for the high-volume group. After adjusting for baseline factors, low- and intermediate-volume operators were not significantly associated with major complications. This study questions the relationship between operator volume and PCI complications in the current era.

Aged↗
PubMed2005

Acute toxicity of intravenously administered microfabricated silicon dioxide drug delivery particles in mice: preliminary findings.

BACKGROUND AND OBJECTIVE: Microfabricated particles with nanosized features may serve an important role in the next generation of drug delivery vehicles. Microfabrication (micro-electromechanical systems) technologies offer the promise of both structural elements (e.g., pores, reservoirs) and electromechanical features (e.g., timers, valves, actuators) built into a single particle. In order to serve as carriers to deliver drugs to systemic sites of action, such as tumors, the particles must be safe to administer intravenously. An acute safety study was performed in a mouse model, using intravenous injection of solid silicon dioxide particles created to simulate the size and shape of potential targeted drug delivery vehicles. DESIGN: Two-micron thick, square and circular, parallelepiped-shaped particles were produced with varying sizes of 2 microm, 5 microm and 10 microm using microfabrication techniques and injected into groups of mice (six mice per group) over a range of doses. End-points included acute lethality, clinical signs of toxicity and weight loss. Sections of major organs were sampled for histological examination. RESULTS: At dose levels of 1 x 10(8) particles per mouse, circular particles of 2 microm and 5 microm showed no signs of acute toxicity. Similar results were obtained with the 2 microm and 5 microm square silicon dioxide particles; however, 14-day necropsy indicates fewer 5 microm circular particles in the lung than 5 microm square particles, indicating that the shape of the particles may impact on safety. Acute lethality was observed for 10 microm particles; none of the mice injected with the 10 microm particles survived except at very low dose levels of 6 x 10(5) particles per mouse. CONCLUSIONS: Solid silicon particles greater than 5 microm in their largest dimension are cleared in the lungs and are not safe for intravenous delivery. Particles of 2-5 microm in size do not lodge predominantly in the lung and do not cause acute toxicity, but accumulate in organs such as the liver and spleen. Possible chronic toxicities associated with organ uptake of such non-biodegradable particles have yet to be addressed.

Animals↗
PubMed2004

Expression of cytokeratins 7 and 20 in Helicobacter pylori-associated chronic gastritis in children.

Helicobacter pylori gastric infection induces structural changes in the gastric epithelium. Among them, variations in the expression of cytokeratins have been reported in adult patients. In the present study, we describe the expression of CK7 and CK20 in gastric samples taken from the antrum in three groups of pediatric patients: (A) Helicobacter pylori-associated chronic gastritis (mean age: 11.4 years); (B) previous H. pylori chronic gastritis patients (mean age: 9.4 years); and (C) controls (mean age: 8.8 years). In all, the presence of sulfomucins was assessed with Alcian blue-periodic acid-Schiff pH 1.0. Immunoreactivity was graded as absent (0), weak (1+), moderate (2+), or intense (3+), in accordance with the intensity of the staining, and its distribution as focal or diffuse. CK7 reactivity was 2+ either focal or diffuse in all group A biopsies. The reactivity was more evident in the cells at the neck of the glands, in the areas with more inflammatory infiltrates, decorating long vertical segments of epithelium. In groups B and C, CK7 reactivity was also focal and 1+ at the cells of the necks of the glands. However, group B presented longer vertical segments of positive cells as compared to group C, and shorter than those of group A. The deeper glandular structures were focally 1+ in both groups. CK20 expression was comparable in all three groups, depicting a 2+ diffuse reactivity at the surface epithelium and interposed pits with absence or focal reactivity at the neck and coiled gland areas. Ki-67 immunostaining paralleled that of the CK7. Staining for sulfated mucosubstances was positive in two of five cases of groups A and B, and in none of the cases of group C. We conclude that: (1) the long segments of CK7-positive glandular necks in H. pylori cases most probably indicate intense regenerative activity during active inflammation; (2) eradication of H. pylori does not warrant ad integrum restitution since long segments of Ki-67+, CK7+ cells at the germinative compartment of the glands (as well as cells with sulfomucins) were still recognizable in ex- H. pylori patients; (3) finally, differing from what happens in adults, children somehow manage to maintain fully differentiated CK20+ superficial epithelium while the H. pylori is in action.

Adult↗
PubMed2004

Medication non-adherence in women with fibromyalgia.

OBJECTIVE: To identify the determinants of medication non-adherence in women with fibromyalgia (FM). METHODS: Participants included 10 rheumatologists and 127 women recruited from tertiary care hospitals and the community. Demographic, clinical and psychosocial characteristics and patient-physician discordance were assessed at the baseline visit. Non-adherence was assessed 2 weeks later. Multivariable generalized estimating equations were used to identify determinants of non-adherence to medication. RESULTS: The average age of the women was 50.4 (s.d. 10.5) yr and the mean disability score was 60.3 (16.0) yr. Sixty (47.2%) women were non-adherent to medication; 20 (33.3%) of these were intentionally non-adherent, 24 (40.0%) were unintentionally non-adherent, and the remaining subjects were both. Overall non-adherence was predicted by higher patient-physician discordance. Unintentional non-adherence was predicted by community subjects, not being under a rheumatologist's care, less disease activity, less use of instrumental coping, and higher patient-physician discordance. Intentional non-adherence was predicted by shorter duration under a rheumatologist's care and higher patient-physician discordance. CONCLUSION: The therapeutic relationship, in addition to clinical and psychosocial characteristics, influenced non-adherence to medication.

Adaptation, Psychological↗
PubMed2004

Interventions for tears of the rotator cuff in adults.

BACKGROUND: Tears of the rotator cuff tendons, which surround the joints of the shoulder, are one of the most common causes of pain and disability in the upper extremity. OBJECTIVES: To review the efficacy and safety of common interventions for tears of the rotator cuff in adults. SEARCH STRATEGY: We searched the Cochrane Musculoskeletal Injuries Group specialised trail register (July 2002), the Cochrane Controlled Trials Register (The Cochrane Library issue 2, 2002), MEDLINE (1966 to December 2001), EMBASE (1974 to December 2001), Biological Abstracts (1980 to December 2001), LILACS (1982 to December 2001), CINAHL (November 1982 to December 2001), Science Citation Index and reference lists of articles. We also contacted authors and handsearched conference proceedings focusing on shoulder conditions. SELECTION CRITERIA: Randomised or quasi-randomised clinical trials involving tears of the rotator cuff were the focus of this review. All trials involving conservative interventions or surgery were included (non-steroidal anti-inflammatory drugs, intra-articular or subacromial glucocorticosteroid injection, oral glucocorticosteroid treatment, physiotherapy, and open or arthroscopic surgery). DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed suitability for inclusion, methodological quality and extracted data. Dichotomous data were presented as relative risks (RR) and 95% confidence intervals (CI), using the fixed effects model. MAIN RESULTS: Eight trials involving 455 people were included and 393 patients analysed. Trials were grouped in eight categories of conservative or surgical treatment. The median quality score of all trials combined was 16 out of a possible 24 points, with a range of 12-18. In general, included trials differed on diagnostic criteria for rotator cuff tear, there was no uniformity in reported outcome measures, and data which could be summarised were rarely reported. Only results from two studies comparing open repair to arthroscopic debridement could be pooled. There is weak evidence for the superiority of open repair of rotator cuff tears compared with arthroscopic debridement. REVIEWER'S CONCLUSIONS: There is little evidence to support or refute the efficacy of common interventions for tears of rotator cuff in adults. As well as the need for further well designed clinical trials, uniform methods of defining interventions for rotator cuff tears and validated outcome measures are also essential.

Adult↗
PubMed2004

Hemorphins: substrates and/or inhibitors of dipeptidyl peptidase IV. Hemorphins N-terminus sequence influence on the interaction between hemorphins and DPPIV.

Hemorphins are endogenous peptides belonging to the family of "atypical" opioid peptides released from sequentially hydrolyzed hemoglobin. In this paper, we report an inhibitory effect of these peptides on dipeptidyl peptidase IV (DPPIV) activity, known to be involved in regulatory functions such as the activation or inactivation of peptides. The structure activity research revealed that hemorphins N-terminus sequence influences nature of the interaction between hemorphins and DPPIV. Kinetic studies conducted with purified DPPIV demonstrated that hemorphin-7 (H7) constitutes a good substrate (K(cat)/K(m) of 137 mM(-1) s(-1)) for this enzyme but could also act as a selective competitive inhibitor by substrate binding site competition. These blood-derived peptides could represent endogenous regulators of this enzyme activity.

Animals↗
PubMed2004

[Focused lithotripsy in the treatment of tendinosis calcarea of the shoulder: results at 2 months and one year].

OBJECTIVE: The authors report their experience with extracorporeal lithotripsy in 30 patients with calcific tendinosis of the rotator cuff. MATERIALS AND METHOD: This technique is based upon the utilization of high-energy shockwaves (6000 shocks in 3 sessions Day 1, D8, D30) under continuous ultrasound localization of the lesion (EPOS Ultra1). Calcification were evaluated at plain film, US and CT to characterize their length and features. RESULTS: Complete or partial resorption of calcifying deposits within 2 months and one year was observed in 27.5% and 25% of cases respectively. Clinical improvement results are encouraging at two months (50%), but reduced at one year (28.5%), consistent with the rate of resorption of calcifications. CONCLUSION: This painful, long, and expensive technique seems to be disappointing in the treatment of the calcific tendinosis.

Adult↗
PubMed2004

[Chromosome 22q11 deletion syndrome and its relevance for child and adolescent psychiatry. An overview of etiology, physical symptoms, aspects of child development and psychiatric disorders].

22q11.2 deletion syndrome is the most common interstitial deletion syndrome in humans. Patients with this syndrome can show a variety of somatic symptoms, especially characteristic facial abnormalities, heart defects, thymic hypo- or aplasia and velopharyngeal dysfunction with or without cleft palate. Disturbancies in motor, language, cognitive and social development are typical, as well as psychiatric disorders. Psychiatric disorders in children and adolescents are mostly attention-deficit/hyperactivity disorder, affective disorders, and autism spectrum problems. Schizophrenia in adults seems to be caused by 22q11.2 deletion in about 2% of all patients. We review current knowledge about etiology, physical features, developmental aspects and psychiatric comorbidity in 22q11.2 deletion syndrome as well as possible therapeutic interventions. Clinical criteria for genetic examinations on 22q11.2 deletion in children and adolescents with psychiatric disorders are defined. Until now 22q11.2 deletion is underdiagnosed in this population--despite of its clinical relevance.

Abnormalities, Multiple↗
PubMed2004

Hierarchical assembly of cell-matrix adhesion complexes.

The adhesion of cells to the extracellular matrix is a dynamic process, mediated by a series of cell-surface and matrix-associated molecules that interact with each other in a spatially and temporally regulated manner. These interactions play a major role in tissue formation, cellular migration and the induction of adhesion-mediated transmembrane signals. In this paper, we show that the formation of matrix adhesions is a hierarchical process, consisting of several sequential molecular events. One of the earliest steps in surface recognition is mediated, in some cells, by a 1 microm-thick cell-surface hyaluronan coat, which precedes the establishment of stable, cytoskeleton-associated adhesions. The earliest forms of these integrin-mediated contacts are dot-shaped FXs (focal complexes), which are formed under the protrusive lamellipodium of migrating cells. These adhesions recruit, sequentially, different anchor proteins that are involved in binding the actin cytoskeleton to the membrane. Conspicuous in its absence from FXs is zyxin, which is recruited to these sites only on retraction of the leading edge and the transformation of the FXs into a focal adhesion. Continuing application of force to focal adhesions results in the formation of fibrillar adhesions and reorganization of the extracellular matrix. The formation of these adhesions depends on actomyosin contractility and matrix pliability.

Actomyosin↗
PubMed2004

Effects of cardiac rehabilitation on exercise capacity in Type 2 diabetic patients with coronary artery disease.

AIM: To determine whether Type 2 diabetic patients with coronary disease can obtain, after cardiac rehabilitation, a similar benefit on exercise capacity to non-diabetic coronary individuals. RESEARCH DESIGN AND METHODS: Fifty-nine Type 2 diabetic patients and 36 age-matched non-diabetic patients were enrolled in a 2-month cardiac rehabilitation programme, after an acute coronary event. At the beginning and at the end of the cardiac rehabilitation programme, each subject underwent a cardiopulmonary exercise test to assess exercise capacity as measured by peak workload, duration of test, maximal heart rate, peak VO2 and anaerobic threshold. The two groups of patients were not different in age, sex ratio, type of coronary event or left ventricular ejection fraction. RESULTS: The baseline exercise capacity parameters were not different between diabetic and non-diabetic subjects. After cardiac rehabilitation, improvement of exercise capacity was significantly less in patients with diabetes compared with those without diabetes: peak workload (19% vs. 29%, P = 0.022), peak VO2 (13% vs. 30%, P = 0.002), anaerobic threshold (12% vs. 31%, P = 0.017). In the diabetic patients, a significant inverse relation between fasting blood glucose and change in peak VO2 was observed on both univariate (r = -0.40, P = 0.002) and multivariate (P = 0.001) analyses. CONCLUSIONS: The benefit of cardiac rehabilitation, after an acute ischaemic heart event, in exercise capacity is significantly lower in Type 2 diabetic patients. The response to cardiac rehabilitation in those with diabetes appears to be influenced by blood glucose levels.

Cholesterol↗
PubMed2004

Use of quantitative antibiogram analysis to determine the clonality of coagulase-negative Staphylococcus species from blood culture.

Two phenotypic methods, quantitative antibiogram analysis and colony morphology, were compared to pulsed-field gel electrophoresis (PFGE) for distinguishing the clonality of coagulase-negative Staphylococcus (CNS) species. The results of these three methods were correlated with the patients' clinical findings for 23 episodes in which CNS species were isolated from two blood culture bottles within a 24-h period. Quantitative antibiogram and colony morphology at 24 h correlated with PFGE typing in 21 (91%) and 20 (87%) episodes, respectively. All episodes associated with CNS strains with identical PFGE patterns had quantitative antibiogram similarity coefficients < 10, whereas most episodes associated with strains with different PFGE patterns had quantitative antibiogram similarity coefficients >or= 17. The CNS isolate pairs were less likely to be associated with infection if the strains had different PFGE types or a quantitative antibiogram similarity coefficient >or= 17. Clinical microbiology laboratories should consider use of the quantitative antibiogram similarity coefficient to aid clinicians in distinguishing infection-associated CNS blood isolates from contaminants.

Adolescent↗
PubMed2003

Living-related bowel transplantation to treat short bowel syndrome in a four-year-old child: a case report.

PURPOSE: Short bowel syndrome (SBS) is an extremely challenging clinical problem in children. Although many patients can be maintained for a period of time on total parenteral nutrition (TPN), many of these children suffer from the morbidity and mortality associated with sequential central line infections, venous thromboses, and TPN-induced liver failure. Intestinal transplantation often is the only chance for long-term survival. Unfortunately, many children die every year waiting for size-matched cadaveric intestine to become available. METHODS: After our success with living-related bowel transplantation in adults, the authors successfully transplanted 150 cm of maternal ileum into a 4-year-old 10-kg child with profound malnutrition from SBS and advanced TPN-induced liver failure. Because of the size mismatch, the abdominal cavity could not be closed primarily. The defect was covered with absorbable mesh and subsequently with skin graft. RESULTS: The patient is home with excellent bowel and liver function, off hyperalimentation, and on a regular diet. No rejection has been encountered. CONCLUSIONS: Living-related intestinal transplantation is a life-saving alternative to cadaveric intestinal transplantation in children with short bowel syndrome.

Child, Preschool↗
PubMed2003

In vitro metabolism of LVV-Hemorphin-7 by renal cytosol and purified prolyl endopeptidase.

The metabolism of LVVH7, an endogenous peptide obtained by cathepsin D hydrolysis of the beta chain of hemoglobin, was studied, in vitro, in the presence of cytosol of rat kidney and compared with angiotensin IV. High metabolic activity was found against these two peptides (half life time < 2 min) in this subcellular fraction. The main products of LVVH7 metabolism by renal cytosol are VVH7, H7 and LVVH6 suggesting both aminopeptidase and carboxypeptidase activities. The use of PEP inhibitor in kidney cytosol permitted to demonstrate the major role of prolyl endopeptidase (PEP) in LVVH7 degradation. This fact was reinforced by a kinetic study investigated with purified enzyme (Km/Vmax about 238 mM-1 s-1 and close to that observed for angiotensin related peptides).

Animals↗
PubMed2003

Detrusor resistive index evaluated by Doppler ultrasonography as a potential indicator of bladder outlet obstruction.

OBJECTIVES: To appraise detrusor blood flow by Doppler ultrasonography in men with suspected bladder outlet obstruction (BOO) to determine whether this imaging technique provides useful information for the assessment of BOO. Experimental studies have shown that BOO is associated with reduced blood flow to the detrusor. METHODS: Twenty-nine consecutive men with lower urinary tract symptoms were prospectively enrolled. A urodynamic pressure-flow study was performed by the urologist to determine BOO, and Doppler ultrasonography was subsequently performed by the radiologist. The physicians were unaware of the other's results. Scanning was performed on a filled and empty bladder. Arterial blood flow was measured at three distinct sites, the two lateral walls and the trigone, and the resistive index (RI) of each site was calculated (RI = (V(MAX) - V(MIN))/V(MAX)). For each patient, the arithmetic average of the three RIs was defined as the detrusor RI. The findings were compared between patients with and without evidence of BOO. A logistic regression model tested the predictive value of the RI. RESULTS: According to the pressure-flow study results, 22 (75%) and 7 (25%) of the 29 patients were diagnosed as having or not having BOO, respectively. A statistically significant difference was found between the detrusor RI in the obstructed versus nonobstructed patients in both full (P <0.001) and empty (P <0.03) bladder states (0.79 versus 0.68 and 0.74 versus 0.66, respectively). Our logistic regression model predicted BOO with an overall accuracy of 86%, positive predictive value of 95%, and negative predictive value of 57%. CONCLUSIONS: The RI of arterial blood flow in the detrusor measured by Doppler ultrasonography provides important predictive information for the presence of BOO. Additional studies are warranted to validate our results and explore the role of Doppler ultrasonography in the management paradigms of patients with suspected BOO.

Aged↗