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Biomedical subjects

M Cohen

Publications and source records attributed to M Cohen.

At least 271 records · Page 15Linked to original sources
PubMed1998

Astrocytes regulate microglial phagocytosis of senile plaque cores of Alzheimer's disease.

We have developed an in vitro model in which isolated senile plaque (SP) cores are presented to rat microglial cells in culture. Microglia rapidly phagocytosed, broke apart, and cleared SP cores. However, when cocultured with astrocytes, microglial phagocytosis was markedly suppressed, allowing the SPs to persist. Suppression of phagocytosis by astrocytes appears to be a general phenomena since microglia in the presence of astrocytes showed reduced capacity to phagocytose latex beads as well. The astrocyte effect on microglia is related in part to a diffusible factor(s) since astrocyte- but not fibroblast-conditioned media also reduced phagocytosis. These results suggest that while microglia have the capacity to phagocytose and remove SPs, astrocytes which lie in close association to microglia may help prevent the efficient clearance of SP material allowing them to persist in Alzheimer's disease.

Alzheimer Disease↗
PubMed1998

Cardiac arrest in the OR: how are our ACLS skills?

PURPOSE: While advanced cardiac life support (ACLS) training is widely available, it is not mandatory for all anaesthetists. We hypothesised that adherence to ACLS guidelines during resuscitation of ventricular fibrillation (VFib) as assessed in a simulator environment would be poor by anaesthetists not trained in ACLS compared with those who had received training. METHODS: With approval by the ethics review board, 89 subjects participated in the study. The simulation system consisted of a computer controlled mannequin with lifelike qualities set in a mock operating room. Each subject was given a test scenario that contained several standard anaesthetic problems. A VFib cardiac arrest occurred after approximately one hour into the simulation. A perfect score (score = A) defined complete compliance with the ACLS guidelines, whereas minor deviations (score = B) included changes in energy levels, drug doses or treatment order. The failure to discontinue the anaesthetic, defibrillate or administer epinephrine were considered major deviations (score = C). RESULTS: Eight subjects followed the ACLS guidelines (9%, score = A), while 27 subjects showed minor (30%, score = B) and 54 subjects major deviations (61%, score = C). Sixty-two of the 89 participants (70%) had taken the ACLS course and achieved higher scores than did anaesthetists without such training (P < 0.05). Forty-two participants (47%) did not discontinue the anaesthetic, 10 (11%) never gave epinephrine and 5 (6%) never used the defibrillator. CONCLUSION: Adherence to ACLS guidelines was poor. A greater proportion of subjects without previous ACLS training had deviations from protocol than did subjects who had received training. We need to consider ways to ensure that anaesthetists obtain and retain resuscitation skills according to ACLS guidelines.

Adult↗
PubMed1998

Ureteral compression and obstruction by spine rods.

We present a case of extrinsic compression of a ureter by spinal fixation hardware and adjacent fibrosis that resulted in progressive obstructive hydronephrosis, loss of renal function, and, ultimately, nephrectomy.

Child, Preschool↗
PubMed1998

Towards a framework for women's health.

The health of women involves their emotional, social, cultural, spiritual and physical well-being and is influenced by social, political and economic factors, as well as by a woman's biology. This definition of women's health provides the conceptual framework for a relevant and effective approach to patient education, health promotion and disease prevention activities in women. Such activities must focus not only on diseases that are more common, more prevalent or more serious in women, but also on priority health issues identified by women themselves, the diversity of women, the determinants of health and above all, the impact of gender on health. These programs must also be based on knowledge resulting from gender sensitive, bias-free health research. The traditional oppression and disempowerment of women must also be addressed at both personal and societal levels, thus broadening our approach so that we become social as well as health activists.

Counseling↗
PubMed1998

Gamma probe-guided sentinel node biopsy--optimal timing for injection.

AIMS: We initiated a Phase I feasibility study using a gamma-detecting probe (GDP) and radiolabelled colloid to localize the sentinel lymph node (SLN) in breast cancer. The aim of the study was to establish the ideal timing for injection and examine any possible exclusion criteria for this method. METHODS: Thirty breast cancer patients diagnosed by fine needle aspiration (FNA) were included in this study. All were injected with 60 MBq rhenium colloid labelled with 99mTc (Tck-17). Scintigraphy was done 20 min, 2, 6 and 25 hours post-injection. Patients were then taken to surgery where they were injected with patent blue dye. During surgery, the SLN was located with a GDP (Neoprobe Model 1000). In 28 patients, the SLN was identified by scintigraphy 2 hours after injection, identical to the images seen after 24 hours. RESULTS: In all 28 patients, the SLN was found by the GDP during surgery. In 26 patients the SLN was dyed blue. The two patients with no SLN localization had received prior radiation. Pathology disclosed SLNs with metastases in seven patients. Two patients had a negative SLN but had an axillary lymph node replaced by tumour. CONCLUSIONS: Two to 24 hours prior to surgery is suitable timing for injection. Previous radiotherapy predicts failure for this procedure. Further studies are needed to find the exact false-negative rate of this method for breast cancer.

Adult↗
PubMed1998

Efficacy of analgesics in chronic pain: a series of N-of-1 studies.

Rational drug treatment of chronic musculoskeletal pain remains a challenge. Although commonly prescribed, the true efficacy of opioid analgesics or of nonsteroidal antiinflammatory drugs remains to be established. Using an N-of 1 design, eight patients with regional cervicobrachial pain received ibuprofen 800 mg/day, codeine 120 mg/day, or placebo during six 2 week periods. Clinical outcomes were assessed by pain diary, VAS of pain and change in pain, and uptime/downtime estimates. In none of the five subjects who completed the 12-week trial was analgesic efficacy of either drug shown. Major psychosocial and other medical influences on the subjects' status were encountered. The N-of 1 methodology is appropriated for evaluating true efficacy of pharmacotherapy in patients with regional musculoskeletal pain.

Adult↗
PubMed1998

Bleeding Complications and INR Control of Combined Warfarin and Low-Dose Aspirin Therapy in Patients with Unstable Angina and Non-Q-Wave Myocardial Infarction.

The purpose of this study was to compare bleeding complications in patients with non-Q-wave myocardial infarction and unstable angina receiving combination therapy with aspirin plus warfarin versus aspirin alone. A post-hoc analysis was performed on patients enrolled in the Antithrombotic Therapy in Acute Coronary Syndrome (ACTACS) study, which was a prospective, randomized, multicenter trial of antithrombotic therapy in unstable angina or non-Q-wave myocardial infarction. A total of 358 patients admitted within 48 hours of chest pain were randomized to antithrombotic therapy with either (1) aspirin alone or (2) aspirin (162.5 mg) plus heparin followed by aspirin plus warfarin, and were prospectively followed up for 12 weeks. Major and minor bleeding episodes, hemoglobin levels, and prothrombin times or INR levels were prospectively recorded. Major bleeding episodes were subclassified as relating to CABG/PTCA or not. The rate of major bleeding complications not associated with CABG or PTCA was 2.0%, and did not differ between therapy assignments. Among 55 patients undergoing CABG, 29 (53%) required transfusion of two or more units of blood. Minor bleeding was also infrequent (2.8%). All patients with minor bleeding had a full clinical recovery, and only one patient with a major bleed resulted in minor disability. Warfarin was well managed, with 50% of INRs falling between 1.9 and 2.7. Combination therapy with low-dose aspirin and warfarin (INR mean 2.5) produces an insignificant rise in the incidence of major and minor bleeding. These events are infrequent and do not usually result in major disability. The effect of longer duration combination therapy remains to be determined.

Journal Article↗
PubMed1998

Operative ultrasonography for upper genital tract pathology.

PURPOSE: A procedure using transvaginal sonohysterography (SHG) to perform operative intrauterine biopsies and resections is described. METHODS: Seven women, six with intrauterine pathology noted on diagnostic SHG and one with a thickened endometrium noted on transvaginal ultrasonography, underwent attempted operative SHG. The indications were peri- and postmenopausal bleeding (n = 4) and infertility requiring assisted reproduction (n = 3). Access to the uterine cavity was accomplished with a 9-F cervical access catheter (CAC) with a 3-ml balloon (BEI Medical Systems, ZSI Gynecology Products Division, Chatsworth, CA), which was placed in the cervical canal or lower uterine segment. Depending on the position of the noted uterine pathology, a 6-F uterine ostial access catheter (UOAC) (BEI Medical Systems, ZSI Gynecology Products Division) was placed through the CAC. The uterine cavity was distended with 5-10 ml of 1% Lidocaine and a 3-F loop grasper or finger-like biopsy grasper was then passed through the UOAC or a 5-F operative instrument directly within the CAC with attempted resection under ultrasound guidance. Biopsied samples were sent to pathology for definitive diagnosis. Office hysteroscopy was then performed to confirm adequate resection. RESULTS: Three of six patients had adequate resection or biopsy of intrauterine pathology, while the seventh patient successfully had a directed biopsy of the fundal cavity under ultrasound guidance. In one case, the visualized lesion could not be grasped. In the other two cases, each patient had severe cervical stenosis and declined in-office cervical dilation precluding the procedure. Each procedure was well tolerated, with an average time from start to finish of about 25 min (range, 18-43 min) without complications. CONCLUSIONS: Operative SHG makes it possible to resect and biopsy intrauterine pathology often missed on Pipelle sampling. If found to be as effective as hysteroscopy, operative SHG would provide a cost-effective alternative. Further study is ongoing to perfect the existing instruments to allow removal of larger lesions both safe and possible.

Biopsy↗
PubMed1998

Pregnancy outcome in familial homozygous hypercholesterolemic females treated with long-term plasma exchange.

BACKGROUND: The use of plasma-exchange therapy has increased the longevity of patients with homozygous familial hypercholesterolemia (HFH), and pregnancy in affected women is expected to become more common. We describe the clinical course, feasibility and risks of repeated pregnancies in patients with HFH treated by long-term plasma exchange. METHODS: We followed the clinical course of five pregnancies in two HFH patients, with attention to the effect of repeated plasma exchange on maternal and fetal status; specifically, lipid profile, hemodynamics, and uteroplacental circulation on Doppler flow study. RESULTS: Increasing the frequency of plasma-exchange therapy prevented the extreme serum cholesterol elevation that occurs in pregnant HFH patients and was associated with a significant improvement in uteroplacental circulation. In four pregnancies the clinical course was uneventful, ending in normal deliveries of full-term infants with heterozygous familial hypercholesterolemia. The third pregnancy of one of the patients had to be terminated owing to the development of hypotension and syncope during plasma exchange because of severe aortic stenosis. CONCLUSIONS: Repeated pregnancies in HFH patients treated by long-term plasma exchange are feasible but may be associated with untoward effects, especially hemodynamic compromise. The frequency of plasma exchange therapy should be increased to prevent marked hypercholesterolemia and its possible deleterious effect on maternal and fetal status. Cardiac evaluation with close hemodynamic monitoring are needed during pregnancy to detect complications of the cardiac valvular lesion and the coronary atherosclerosis that are associated with HFH.

Adult↗
PubMed1998

Peri-operative dysrhythmias in patients undergoing major vascular surgery--a preliminary report.

The objective of this prospective study was to determine the nocturnal/diurnal distribution of peri-operative cardiac dysrhythmias in patients with coronary artery disease undergoing major vascular surgery. Eight patients with significant coronary artery disease undergoing major vascular surgery were studied. Continuous Holter monitoring was performed on each patient from approximately 1 h pre-operatively until 2-5 days post-operatively. Frequencies of isolated supraventricular and ventricular premature beats, and runs of supraventricular and ventricular premature beats were calculated for 6-h periods (00.00-06.00; 06.00-12.00; 12.00-18.00; 18.00-24.00 hours). Supraventricular tachycardia occurred significantly more frequently between 00.00 and 06.00 hours than during the other 6-h periods studied in the post-operative period following major vascular surgery.

Aged↗
PubMed1998

New therapies for unstable angina and non-Q-wave myocardial infarction: recent clinical trials.

Thrombosis after the rupture of an atherosclerotic plaque often precipitates the acute coronary syndromes of unstable angina and myocardial infarction. The combination of aspirin and heparin has been shown to reduce the occurrence of both symptomatic and asymptomatic ("silent") ischemia, myocardial infarction, and death in patients with these syndromes. However, heparin and aspirin each have significant limitations as antithrombotic drugs. Additionally, coagulation abnormalities may persist for several months after an acute ischemic event, and long-term anticoagulation may be beneficial. Because of the need for frequent anticoagulation monitoring and dosage adjustment, the use of heparin is limited to short-term treatment during the acute in-hospital phase. Recently several novel antithrombotic treatments have been developed. The benefits of direct thrombin inhibitors, platelet fibrinogen receptor antagonists, and low-molecular-weight heparins in the treatment of acute coronary syndromes have been demonstrated in randomized clinical trials.

Angina, Unstable↗
PubMed1998

Female TBI patients recover better than males.

The purpose of the present study was to look at possible gender differences in outcome after severe traumatic brain injury. Three hundred and thirty four consecutive patients, 72 females and 262 males, age range 5-65 years, were included in the study. Age range and severity of injury, evaluated by duration of unconsciousness, did not differ between male and female patients. Predicted outcome at the time of discharge from an in-patient rehabilitation programme was evaluated according to work capacity. Female TBI patients had a better predicted outcome (p < 0.015). It is suggested that progesterone, acting as a neuroprotective agent, may explain this difference in outcome.

Adolescent↗
PubMed1998

The association of soft-tissue rheumatism and hypermobility.

Soft-tissue rheumatism (STR--tendinitis, bursitis, fasciitis and fibromyalgia) accounts for up to 25% of referrals to rheumatologists. The estimated prevalence of generalized hypermobility in the adult population is 5-15%. There have previously been suggestions that hypermobile individuals may be predisposed to soft-tissue trauma and subsequent musculoskeletal pain. This study was designed to examine the mobility status and physical activity level in consecutive rheumatology clinic attendees with a primary diagnosis of STR. Of 82 patients up to age 70 yr with STR, 29 (35%) met criteria for generalized hypermobility. Hypermobile compared to non-hypermobile individuals reported significantly more previous episodes of STR (90% vs 51%, P < 0.01), and more recurrent episodes of STR at a single site (69% vs 38%, P < 0.001). Although we were unable to show any difference in the time spent carrying out physical activity between the two groups, the hypermobile patients were performing significantly more repetitive activities. When specific anatomical sites of STR were analysed, small joints (elbows, hands and feet) currently affected with STR were more likely to show localized hypermobility than if those joints were asymptomatic. These findings suggest that hypermobility may be a factor in the development of STR. Repetitive activity may be a contributing factor towards STR in some hypermobile individuals.

Adolescent↗
PubMed1998

Resistance to antimicrobial chemotherapy: a prescription for research and action.

The growing problem of resistance to antimicrobial chemotherapy was discussed by participants at the February 1995 workshop at Emory University on population biology, evolution, and control of infectious diseases. They discussed the nature and source of this problem and identified areas of research in which information is lacking for the development of programs to control of the emergence and spread of resistant bacteria. Particular attention was given to theoretical (mathematical modeling) and empirical studies of the within and between-host population biology (epidemiology) and the evolution of microbial resistance to chemotherapeutic agents. Suggestions were made about the kinds of models and data needed, and the procedures that could be employed to stem the ascent and dissemination of resistant bacteria. This article summarizes the observations and recommendations made at the 1995 meeting and in the correspondence between participants that followed. It concludes with an update on the theoretical and empirical research on the between- and within-host population biology and evolution of resistance to antimicrobial chemotherapy most of which has been done since that meeting.

Bacteria↗
PubMed1998

The granulometer--a pocket scale for the assessment of wound healing.

In spite of the availability of high-tech devices for wound assessment, plastic surgeons recognize that the color and confluence of granulation tissue are the most important indicators of open-wound healing. We developed a simple and inexpensive pocket-size scale--the Granulometer--to facilitate a finer assessment and to standardize the documentation of wound healing. This device overcomes limitations set by conditions such as lighting or recent exposure to other wounds that could distort the examiner's perception of the wound in question. In this study we examined the inter- and intraobserver variations in judgment, and the validity of the Granulometer. Our results demonstrate that skin graft viability can be predicted accurately by this eight-grade scale. Since graft survival depends on proper wound healing, we believe that the Granulometer can also be used for fine assessment of wound treatment. The low inter- and intraobserver variations indicate that the Granulometer measurements are both reproducible and accurate.

Granulation Tissue↗
PubMed1998

Single-injection gamma probe-guided sentinel lymph node detection in 40 melanomatous lymphadenectomies.

The aim of the study was to evaluate single-injection gamma probe-guided sentinel lymph node (SLN) detection, applied in 40 melanomatous selective sentinel lymphadenectomies (SSLNDs). Thirty-four patients underwent preoperative lymphoscintigraphy, intraoperative SLN identification by a gamma-detecting probe and blue dye, and SLN sampling. The first 11 patients underwent formal lymphadenectomy. The following 23 patients underwent formal lymphadenectomy only when the SLN was involved with tumor. Evaluation included hematoxylin-eosin-stained slide microscopy, monoclonal antibodies to S-100 protein, and the melanoma-associated antigen HMB45. In all patients, single or multiple SLNs were identified by the gamma-detecting probe. However, only 82.5% of these specimens included blue-stained nodes. None of the non-SLN specimens were the exclusive site of metastases. Four patients had metastases in their SLN specimen without non-SLN involvement. We conclude that SSLND can be performed easily and precisely with the exclusive use of the gamma-detecting probe. A single injection is feasible, and decreases operating room contamination and patient discomfort.

Humans↗