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Biomedical subjects

J M Cohen

Publications and source records attributed to J M Cohen.

At least 55 records · Page 3Linked to original sources
PubMed1997

Combination ptosis crutch and moisture chamber for management of progressive external ophthalmoplegia.

BACKGROUND: A 46-year-old woman with a long-standing history of chronic progressive external ophthalmoplegia manifested a primary visual symptom of bilateral ptosis. Previous lid surgery was unsuccessful because of severe sight-threatening exposure keratitis. CASE REPORT: The patient's problem was managed by fabricating a spectacle-mounted combination ptosis crutch and moisture chamber. The custom device successfully provided both cosmetic and visual relief for the patient while maintaining corneal integrity. CONCLUSIONS: This case demonstrates the effectiveness of a dual-purpose appliance that offers a cosmetically viable alternative to ptosis patients who are high-risk surgical candidates because of potential corneal dehydration.

Blepharoptosis↗
PubMed1996

Experience of European collaboration in influenza surveillance in the winter of 1993-1994.

BACKGROUND: The spread of influenza is of major public health concern. Surveillance programmes exist in many countries. We here describe an international collaboration sharing information from Belgium, France, The Netherlands, Portugal and the United Kingdom during the influenza A(H3N2) epidemic occurring in Europe at the end of 1993. METHODS: Procedures for clinical and virological surveillance in each country are described. National data were assembled at one point in each country and entered on a computerized data base in Paris for integration. A background rate of influenza was identified from the two previous winters (1991-1992 and 1992-1993) using the measurement of incidence routinely used in each country. The epidemic in late 1993 was described in relation to the background rate. The proportion of cases in each of three age groups (0-14, 15-44 and 65 years and over) was compared in different stages of the epidemic. RESULTS: All national systems effectively identified the onset and monitored the course of the epidemic. Standardization of incidence data gave only limited assistance to the interpretation of the data. The distribution of cases by age group was similar in the early and late periods of the epidemic in all countries. Increased clinical incidence was matched by a simultaneous increase in positive virus identifications in all countries except England and Wales, where the interval between the week of peak clinical incidence and of peak virus reports is mainly due to a reporting procedure based on date of report received at the Central Public Health Laboratory rather than date of specimen capture. CONCLUSION: An international early warning system for monitoring influenza has been established.

Adolescent↗
PubMed1996

The effect of metformin on the metabolic abnormalities associated with upper-body fat distribution. BIGPRO Study Group.

OBJECTIVE: The constellation of anomalies associated with insulin resistance is a plausible additional cause of ischemic cardiovascular disease and of NIDDM. To test this hypothesis in a primary prevention trial, the effects of metformin as a potential candidate for intervention in the insulin resistance syndrome (IRS) were evaluated in 324 middle-aged subjects with upper-body obesity. RESEARCH DESIGN AND METHODS: Trial patients were selected on the basis of a high waist-to-hip ratio. They were randomly allocated to receive either metformin or placebo, following a double-blind procedure. After 1 year of treatment, the main clinical and biological parameters of the IRS were assessed and their evolution compared between treatment groups. RESULTS: Compared with placebo, metformin induced a significant weight loss, a better maintenance of fasting blood glucose, total and LDL cholesterol levels, and a greater decrease of fasting plasma insulin concentration. Moreover, tissue-type plasminogen activator antigen, a marker of fibrinolytic impairment, showed a significant decrease under metformin. By contrast, metformin treatment had no significant effect on blood pressure or serum triglyceride and HDL cholesterol concentrations. The main side effect of metformin was diarrhea. CONCLUSIONS: The BIGuanides and Prevention of Risks in Obesity (BIGPRO1) results suggest that metformin would be a suitable candidate for long-term intervention for the prevention of diabetes but that its use in a trial of primary prevention of cardiovascular diseases requires either a reevaluation of its properties toward the most potentially atherogenic anomalies of the IRS or a better definition of the target population.

Adipose Tissue↗
PubMed1995

[Microfibroendoscopy of the eustachian tube].

The development of extremely minute high performance optical fibers have made possible fibroscopic examination of the Eustachian tube. We have developed a microfibroendoscopic technique since 1987 to explore the Eustachian tube and the tympanic cavity without opening the tympanic membrane. This technique has been used in 125 patients with chronic otitis. The exploration is performed in the operating theatre during a tympanoplasty procedure. Patients are placed in supine position under general anaesthesia. Endoscopic exploration of the Eustachian tube has demonstrated that tube obstruction is very rare, encountered in only 2% of our cases. The major advantage of the technique is the direct antero-posterior visualization of the middle ear. Viewing the middle ear from this anterior view point, the surgeon can analyze regions unattainable with other techniques. The future challenge for this technique is to achieve the goal of non-invasive surgery of the middle ear.

Endoscopy↗
PubMed1995

Endoscopy of the cerebellopontine angle.

The authors present their experience of 191 patients from June 1990 to December 1993 with endoscopy of the cerbellopontine angle using a limited retrosigmoid approach. The advantages of endoscopy of the cerebellopontine angle are the simplicity and efficiency of the procedure, and less invasive surgery. The authors emphasize the importance of the endoscopic procedure: first in acoustic neuroma surgery to get more accurate information about the relationship between the tumour and the adjacent structures, and to control the lateral end of the internal auditory canal; second in hemifacial spasm or facial neuralgia surgery, intraoperative endoscopy is the key point giving a sure and safe way to recognize the offending vessels.

Cerebellopontine Angle↗
PubMed1994

A glycinergic intervention potentiates the antiseizure efficacies of MK-801, flurazepam, and carbamazepine.

Twenty four hours after mice were forced to swim for up to 10 minutes in cold water, there was a reduction in the ability of MK-801 to antagonize the electrical precipitation of tonic hindlimb extension. Milacemide, a lipophilic prodrug of glycine, restored the antiseizure efficacy of MK-801 to the same level observed in unstressed animals treated with milacemide and MK-801. Stimulation of the glycine-gated chloride ionophore subsequent to the liberation of free glycine could explain milacemide's pharmacologic action as an adjuvant to MK-801. Consistent with this interpretation, milacemide was able to potentiate the antiseizure effects of flurazepam, a benzodiazepine agonist, in stressed and unstressed mice and carbamazepine in unstressed animals. D-cycloserine, a partial glycine agonist with greater specificity for the strychnine-insensitive modulatory site on the NMDA receptor complex, was examined for its effect on MK-801's antiseizure efficacy. At a high dose (320 mg/kg), D-cycloserine alone had an anticonvulsant effect. Moreover, this dose of D-cycloserine administered with MK-801 showed a significantly greater anticonvulsant efficacy than MK-801 alone. The data support the development of glycinergic interventions as adjunctive agents in the pharmacotherapy of seizure disorders.

Acetamides↗
PubMed1994

Sensitivity, specificity and predictive values of health service based indicators for the surveillance of influenza A epidemics.

BACKGROUND: The Regional Influenza Surveillance Group (GROG) is a French surveillance network set up in 1984. It collects virological specimens and health service based indicators on a weekly basis. Our aim was to assess the predictive value of the health service based indicators for the detection of influenza A epidemics. METHODS: Virological data were used as a gold standard for defining the epidemics. For each health service based indicator, a statistical threshold was used as a test for the identification of epidemic weeks. Finally, an epidemiological criterion was defined in order to improve the specificity and the speed of detection of outbreaks. RESULTS: Health service based indicators have a positive predictive value of around 0.80. They also advance the detection of outbreaks by between 1 and 4 weeks. CONCLUSIONS: These indicators are easy to collect and are useful for the surveillance of influenza epidemics. Such a system is the prerequisite for the rational use of preventive tools.

Disease Outbreaks↗
PubMed1994

Hyperhidrosis--a case history.

The authors present a case report on hyperhidrosis. The social and occupational consequences of this disease entity are discussed as well as the genetic implications of this disorder. The medical and surgical treatments of hyperhidrosis are evaluated. The use of infrared imaging techniques as a cost-effective, rapid, noninvasive procedure to diagnose this disorder is described.

Female↗
PubMed1994

[Role of endoscopy and vascular decompression in the treatment of hemifacial spasm].

Although it has long been hypothesized that hemifacial spasm could arise from a conflict between the nerve and the artery, it is very difficult to distinguish between a normal arterial loop and a pathological conflict leading to facial symptoms. Several new elements would help in the definition of the cause and allow less traumatic treatment of idiopathic hemifacial spasm. They include magnetic resonance imagery with CISS sequences, limited retrosigmoid approach, endoscopy of the cerebellopontine angle and monitoring the facial nerve. In our experience with 20 cases, retrosigmoid approach with a combined surgical and endoscopic procedure has led to total involution of the spasms in 80% of the cases.

Adult↗
PubMed1994

The neuroanatomy of post-polio fatigue.

Fatigue is the most commonly reported, most debilitating, and most poorly understood Post-Polio Sequelae (PPS). Postmortem studies of 50 years ago documented frequent and severe poliovirus-induced lesions within the Reticular Activating System (RAS). Recently, neuropsychological testing has documented marked attention deficits in polio survivors reporting severe fatigue. However, neither of these findings has yet been related to the pathophysiology of post-polio fatigue. Magnetic resonance imaging of the brain was performed in 22 polio survivors carefully screened to eliminate the effect of comorbidities. Subjects rated the severity of their daily fatigue and subjective problems with attention, cognition, and memory. Small discrete or multiple punctate areas of hyperintense signal (HS) in the reticular formation, putamen, medial leminiscus, or white matter tracts were imaged in 55% of the subjects reporting high fatigue and in none of those reporting low fatigue. The presence of HS significantly correlated with fatigue severity and subjective problems in attention, concentration, staying awake, recent memory, and thinking clearly. The lack of significant correlations between HS or fatigue severity and age, severity of the acute polio, depressive symptoms, or difficulty sleeping militates against these factors as either causing HS or producing fatigue. These preliminary findings suggest that poliovirus-induced lesions in the Brain Activating System may underlie the subjective fatigue and attention deficits reported by polio survivors.

Adult↗
PubMed1993

A controlled study of brain magnetic resonance imaging in patients with the chronic fatigue syndrome.

Two neuroradiologists compared the brain MR scans of 52 patients with the CDC criteria for the chronic fatigue syndrome (CFS) with those of 52 age and sex matched controls who had undergone imaging because of histories of head trauma or headache. CFS patients had significantly more abnormal scans than controls--27% vs 2%. Abnormalities seen were foci of increased white matter T2 signal in 9 CFS patients and one control and ventricular or sulcal enlargement in 5 CFS patients. Follow up of patients with subcortical signal hyperintensities revealed 3 who had symptoms suggestive of other known medical causes of what appeared to be CFS. The data indicate that some CFS patients have some organic problem manifesting itself on neuroimaging. But, finding MR abnormalities should warn the physician that the patient's symptoms may be secondary to some other medical illness and not simply primary CFS.

Adolescent↗
PubMed1993

Comparison of balloon valvuloplasty with operative treatment for mitral stenosis.

To determine the optimal role for percutaneous balloon mitral valvuloplasty or open mitral commissurotomy, the outcome of 164 consecutive patients undergoing either percutaneous balloon mitral valvuloplasty, open mitral commissurotomy, or mitral valve replacement for mitral stenosis was reviewed. No preoperative differences existed between percutaneous balloon mitral valvuloplasty and open mitral commissurotomy in age, symptoms, or mitral valve characteristics. Symptoms improved similarly in all groups, and median hospital stays after procedures were 2, 9, and 10 days for percutaneous balloon mitral valvuloplasty, open mitral commissurotomy, and mitral valve replacement (p < 0.005). Actuarial survivals at 36 months did not differ significantly (83% +/- 6%, 94% +/- 4%, and 90% +/- 4%). Actuarial freedoms from subsequent mitral valve procedures at 36 months were 66% +/- 7%, 87% +/- 6%, and 100% +/- 13% (p < 0.005), with the linearized rate of subsequent mitral valve procedures being 12% +/- 3%, 4% +/- 2%, and 1.2% +/- 0.8%/patient-year for percutaneous balloon mitral valvuloplasty, open mitral commissurotomy, and mitral valve replacement (p < 0.01). Prior mitral commissurotomy increased the likelihood of subsequent mitral procedures after percutaneous balloon mitral valvuloplasty from 10% +/- 3% to 20% +/- 7%/patient-year.

Adult↗
PubMed1993

Differentiation between MK-801- and apomorphine-induced stereotyped behaviors in mice.

The ability of phencyclidine (PCP) to model schizophreniform psychosis is believed to be related to its ability to produce both hypoglutamatergia and hyperdopaminergia. As such, identification of PCP-stimulated behaviors may be important for the development of animal models of schizophrenia. In this study, MK-801 [(+)-5-methyl-10,11-dihydro-5H- dibenzo[a,d]cycloheptane-5,10-imine maleate], a high-affinity PCP analogue, was administered to mice in order to stimulate "PCP behaviors." These PCP behaviors were compared with behaviors stimulated by apomorphine, a dopamine agonist. Stereotyped behavior was assessed by both visual observations and automated measurements. Visual observations showed highly intense gnawing and sniffing in apomorphine-treated mice and the absence of gnawing in MK-801-treated mice. Automated stereotypic measures showed that, compared with vehicle-treated controls, there were frequent dissociations between MK-801 and apomorphine. Conceivably, a compound that attenuates PCP-stimulated behaviors while sparing apomorphine-stimulated behaviors would possess both antipsychotic efficacy and be devoid of undesirable side effects associated with dopamine blockade.

Analysis of Variance↗
PubMed1993

[Contribution of endoscopy of the cerebellopontine angle by retrosigmoid approach. Neuroma and vasculo-nervous compression].

An endoscopic approach to the cerebellopontine angle has been suggested by several authors over the last 20 years but it is only recently that the technical and operative conditions for successful endoscopy could be met. The retrosigmoid approach provides simple and direct access to the cerebellopontine zone. The endoscope, with its distal light source, provides excellent illumination of a wide visual field within an anatomical site particularly rich in neurovascular structures. Endoscopic and microsurgical techniques may be combined for the surgical management of acoustic neuroma with the advantage of assuring better exposure of structures adjacent to the tumor and better control of the quality of dissection of the fundus of the internal auditory canal. The addition of endoscopic techniques, during surgery for trigeminal neuralgia or unilateral facial spasm, makes it possible to accurately locate the site of neurovascular compression without either retraction of the cerebellum or unnecessary dissection.

Arteries↗
PubMed1993

An overview of enhancement techniques for peripheral field loss.

Practitioners are often reluctant to deal with impaired visual function secondary to peripheral field defects. This article presents a variety of enhancement techniques that help compensate for difficulties encountered by patients with peripheral field loss. We hope the information presented will increase practitioner awareness and help in the selection of the most appropriate treatment for the particular patient.

Eyeglasses↗
PubMed1992

The utilization of a temporal mirror coating on the back surface of the lens as a field enhancement device.

A 37-year-old male had a right homonymous hemianopia due to trauma. During his initial low vision assessment, a small clip-on mirror was dispensed to help him compensate for his field loss. At follow-up, he reported satisfaction with the mirror. He also reported that novelty "look behind you" sunglasses were beneficial to him and less conspicuous than the clip-on mirror. He requested temporal mirror coating on otherwise clear lenses so that he could utilize the glasses at night or on cloudy days. We fabricated this for him and also mounted a small mirror nasally within the vertex distance behind his frame. The fabrication of the two devices will be discussed as well as a comparison of these three field enhancement devices.

Adult↗