Biomedical subjects
Publications and source records attributed to L Cohen.
A strong positive correlation between urinary magnesium and lactate was found in 17 magnesium-depleted patients with echocardiographically proved mitral valve prolapse. The strong correlation over all the range of urinary magnesium values and the significantly increased excretion of lactate suggest urinary magnesium loss in this syndrome.
Two groups of patients with multifocal atrial tachycardia (MAT) were treated with the intramuscular and continuous intravenous magnesium sulphate regimens used in pre-eclampsia. Both routes of administration were successful in causing reversion to sinus rhythm but the intramuscular regimen, by attaining a higher and more sustained serum magnesium concentration, converted the arrhythmia to normal sinus rhythm in a shorter period of time (1-2 hours) than the intravenous regimen (4-8 hours). Magnesium-sparing diuretics should be used in the treatment of patients with chronic obstructive pulmonary disease and congestive heart failure, which are both conditions associated with magnesium deficiency and MAT.
A retrospective analysis was made of the results of the individualized office management of hypercholesterolemia in 37 patients (25 male, 12 female) with severe atherosclerosis (n = 35) or a predisposition to it (n = 2). The effects of diet instruction, diet and a niacin supplement, and diet plus the niacin supplement and probucol were assessed. Diet alone (n = 37) was prescribed for an average of 4.8 years; diet plus niacin (n = 37) for an average of 2.0 years; and diet plus niacin and probucol (n = 19) for an average of 2.9 years. Each patient served as his or her own control. The maximum serum cholesterol at the beginning of the diet period was 8.69 +/- 2.15 mmol/L (336 +/- 83 mg/dL) (mean plus or minus standard deviation; n = 37). The goal cholesterol was less than 5.20 mmol/L (200 mg/dL). On diet alone the cholesterol level fell to 7.21 +/- 1.27 mmol/L (279 +/- 49 mg/dL) (P less than .001); and goal cholesterol was reached by 12 of 37 patients (32.4 percent), but was maintained in none. On adding niacin, the mean cholesterol fell to 6.21 +/- 1.16 mmol/L (240 +/- 45 mg/dL) (P less than .001). The goal cholesterol was reached in 22 of 37 patients (59.4 percent), but was maintained in only 7 of 37 (18.9 percent). Nineteen of 37 patients on diet plus niacin also received probucol. Goal cholesterol was reached in 14 of 19 patients (73.6 percent), and was maintained in 11 of 19 (57.9 percent).(ABSTRACT TRUNCATED AT 250 WORDS)
Forty two TUU have been performed from 1974 to 1986 in children and young adults: the youngest was 10 years, the oldest 26. The mean follow-up has been more than 5 years: 23 bladder exstrophies, 12 neurogenic bladders, 5 mega-ureters and 2 retroperitoneal tumors. TUU were performed after failure of uretero-cysto-neostomies (8/42) ou uretero-sigmoid reimplantation (19/42). The technique with details about drainage (16/42) is described. In 5 cases, complications appeared early: 3 fistulae, 2 sweelings of the anastomosis. tests done 3 months after the operation did not show any other complication in relation with the TUU. Nevertheless one reflux and 3 stenoses of the end of the recipient ureter caused dilatation of two upper urinary tracts. During the long term follow-up, it was necessary to perform 2 nephrectomies of the donor ureter and 5 operations on the end of the recipient ureter. These complications were independant of the TUU. The final result of TUU was excellent.
We describe the technique of intraoperative angioscopy for delineation of peripheral vascular anatomy. Angioscopes with outer diameters of 0.85-2.9 mm have been used during 86 peripheral vascular procedures. Angioscopic inspections were performed during 68 femoral popliteal bypasses, four aortofemoral bypass grafts, one abdominal aortic aneurysm, two extra anatomic axillary femoral bypass grafts, and 11 other vascular procedures. We obtained useful images in 73 of 86 procedures (85%), thereby yielding 118 angioscopic inspections (53 arteries, 37 anastomoses, and 28 vein grafts). Changes in intraoperative management based on angioscopic findings included revision of five of 37 (14%) anastomoses, deletion of four of 31 (13%) completion angiograms, revision of eight of 17 (47%) in situ venous valves, and repetition of thrombectomy in six of seven (86%) cases. In 22 of 73 (30%) peripheral angioscopies, potential causes of graft occlusion were recognized. Complications from intraoperative angioscopy have included one anastomotic flap from intimal disruption that required anastomotic revision. Three small flaps, possibly resulting from angioscopic trauma, were recognized but appeared to have no clinical significance. In conclusion, intraoperative angioscopy provides visual assessment of luminal patency and anastomotic anatomy. This assessment alters intraoperative procedures in some cases and cannot be obtained by angiography.
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A 33-year old Arabian man presented with idiopathic thrombocytopenic purpura that did not respond to steroid treatment or splenectomy. A routine liver scan performed after splenectomy showed a large mass in the liver. Four years later, massive gastrointestinal bleeding led to an emergency laparotomy, which revealed well-differentiated lymphocytic lymphoma extending from the liver to the fundus and lesser curvature of the stomach. A partial gastrectomy was performed. With chemotherapy the liver mass resolved and the platelet counts have normalized for the past 30 months.
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Serotonin (5-HT) uptake was studied in the blood platelets of 10 patients with Duchenne-type muscular dystrophy (DMD) and 7 age-matched controls. Vmax (maximum number of uptake sites) of platelet 5-HT uptake in the DMD patients was significantly less than that of the normal controls. There was no difference in the affinity for 5-HT (Km) between the two groups. There was a significant negative correlation between serum creatine kinase activity and Km of 5-HT uptake in blood platelets of these patients. However, no correlation was found between Km or Vmax and ambulatory status of DMD.
Despite the magnitude and importance of the problem, little is known about why many students are absent from school. This study assessed what a sample of excessively absent students and their parents believed were the reasons for the students' absences. In response to an open-ended question about their main reason for absence, almost half of the students reported a health-related reason. When asked whether any of 15 potential problems contributed to their absence, many reported common and acute physical illnesses, headaches or stomachaches, and other aches or pains. Half mentioned factors relating to low motivation or a concern about the school environment. The parents' responses were remarkably similar except they were more likely to cite emotional problems of the student, school violence, and racial problems. When individual student's responses were compared with those of his or her parents, agreement on individual items were little better than would be expected by chance.
This study explores the feasibility of identifying, for a given tumor and its associated normal tissues, that combination of dosimetric and technical factors which will provide the best chance of achieving local control of the tumor without significant complications. Tumor control probability depends on the number of clonogenic cells surviving the course of treatment, which is a function of the initial tumor volume and the computed cellular surviving fraction. This in turn depends on the physical dose, number of fractions, and overall time. Similarly, the risk of injury to any one associated normal tissue is also a function of dose, field-size, fractions, and time. The best treatment scheme is assumed to be one which maximizes the chance both of tumor control and of avoiding complications. Computer programs can achieve this end by searching a wide range of fractionation schemes and selecting that with the largest therapeutic ratio or probit difference (difference between tumor control and normal tissue damage probabilities). When two or more normal tissues are involved, this process is much more complex. Fractionation schemes that reduce the risk of injury in one tissue may be worse for another. The safest procedure is then one which reconciles these conflicting requirements, searching for that combination of factors which will maximize the conditional probability of controlling the tumor and avoiding injury in any of the several tissues concerned. Results of a computer-derived solution for this type of problem: control of a hypothetical lung cancer associated with lung parenchyma, late-reacting stroma, and acutely reacting esophageal epithelium, are presented.
One hundred and thirteen cases of recurrent and/or unresectable malignant salivary gland tumors, treated with fast neutron therapy at Fermilab between September 1976 and December 1984, are analyzed for local control, sites of failure, and treatment-related morbidity. Sixty-three patients had major and 55 had minor salivary gland tumors. Local control was achieved in 67% of patients with major and 58% of patients with minor salivary gland tumors. In the subgroup of patients with oropharyngeal and oral cavity lesions, 19/24 (80%) had local control. However, only four of 15 patients with maxillary antrum tumors had successful control of their disease. Seventy-four percent of patients with lesions measuring 5 cm or less and 30% of patients with larger lesions had their local disease controlled. Histology did not influence the local control rate. Both observed and adjusted median survival for patients with major salivary gland tumors was 36 months. Disease-free survival was 31 months. Observed and adjusted median survivals for patients with minor salivary gland tumors are 48 and 57 months respectively. Twenty of 86 patients (23%) had major morbidity; this was directly related to the total dose delivered. In the dose range 20-24 Gy the complication rate was 16%. Most of these complications were successfully managed with minimal functional disability. We have concluded that fast neutron irradiation is an appropriate treatment for malignant salivary gland tumors.
Little is known concerning the employment characteristics of hygienists practicing in nontraditional settings. Respondents were identified through screening (n = 38,380) a listing of the entire population of hygienists licensed in the United States. The screening identified 1,301 hygienists practicing in nontraditional settings. These hygienists were mailed comprehensive questionnaires; completed questionnaires were returned by 84.3 percent of the hygienists. Data were collected describing hygienists' reasons for seeking employment in nontraditional settings, their sources of information concerning job opportunities in nontraditional settings, benefits, and job satisfaction. The main source of information concerning employment opportunities in nontraditional settings was "word of mouth." Hygienists were motivated to seek employment in nontraditional settings primarily by a desire for a more challenging position and personal satisfaction. The hygienists were overwhelmingly satisfied with all aspects of nontraditional employment except opportunities for advancement. Respondents were found to receive standard benefits similar to those of employees in other industries.
The cognitive status of 12 clinically stable children with congenital HIV infection, nine of whom were neurologically impaired, age three to nine years, was assessed using the Kaufman ABC test. Seven of the children had ARC; five were diagnosed as having AIDS. The same children were evaluated by standard neurologic examinations with Characterization of tone and fine motor functioning. Two were diagnosed as being mildly retarded; six were borderline; and four tested as being of average intelligence. Visual-spatial perceptual based functioning was found to be more impaired than were abstract reasoning and verbally mediated skills in six (50%) of the patients. This pattern of impaired information processing was found irrespective of overall cognitive status. On neurological and physiatric examination abnormal developmental histories were obtained, or poor fine motor coordination, abnormal tone and gait, and impaired rapidly alternating movements were found in 9 of the 12 subjects. These findings suggest selective impairment in distinct areas of neurologic and neuropsychological functioning during stable phases of HIV infection in a select group of children. These patterns appear to persist over time. They differ from the clustering of impaired skills seen in children of comparable socio-cultural backgrounds without HIV infection. Similarities in functioning are noted between this subgroup of children with AIDS and ARC and comparable groups with cerebral palsy.
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