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Biomedical subjects

L Levin

Publications and source records attributed to L Levin.

At least 37 records · Page 2Linked to original sources

The application of dose intensity to problems in chemotherapy of ovarian and endometrial cancer.

An attempt was made using dose intensity to resolve some of the conflicting issues regarding chemotherapy in ovarian cancer and endometrial cancer. Analyses were done to determine if dose intensity correlates with outcome of first-line and salvage chemotherapy of advanced ovarian cancer and chemotherapy of advanced endometrial cancer. The concept of dose intensity was used to analyze the relative contributions of individual drugs, such as cyclophosphamide, hexamethylmelamine, Adriamycin (Adria Laboratories, Columbus, OH) and cisplatin to outcome, and to suggest how such drugs should be used in combination.

Altretamine

High-dose-intensity regimen of weekly doxorubicin and cisplatin in the treatment of patients with stage III and IV epithelial ovarian carcinoma.

Thirty-seven eligible patients with stage III or IV epithelial ovarian carcinoma were treated with weekly doxorubicin and weekly escalating cisplatin in an attempt to improve outcome by increasing the dose intensity of chemotherapy as compared to more conventional regimens given every 3-4 weeks. There was a 63% clinical response rate, with a median survival time of 18 months. Six patients (16.2%) had a complete surgical/histologic response (negative second-look laparotomy). Two patients had treatment-related deaths, and severe toxicity was responsible for four other patients having to discontinue treatment prematurely. The toxicity of this regimen jeopardized received (as opposed to projected) dose intensity and the regimen therefore offered no improvement compared to other drug combinations and schedules.

Adolescent

CA 125 surveillance and second-look laparotomy in ovarian carcinoma.

CA 125 was evaluated as a tumor marker in 31 patients undergoing treatment for ovarian carcinoma, 17 of whom had second-look laparotomies. At the time of second-look laparotomy, 14 patients had CA 125 values in the normal range. Six of these patients had a positive second-look laparotomy. Although normal CA 125 values do not obviate the need for second-look laparotomy in treatment planning, rising or falling trends reflected clinical disease progression or regression in 80% of the cases.

Adult

Free perforation in Crohn's disease: a report of 33 cases and review of literature.

Thirty-three patients with free perforation in Crohn's disease are described. There are 14 males and 19 females in this series with ages ranging from 14 to 79 years. The sites of perforation were 22 of the ileum, nine colonic, one jejunal, and one gastroduodenal. Toxic megacolon coexisted in two. Reperforation occurred in three. Free perforation was the presenting sign of the disease in three. Steroid therapy coexisted in 16 patients but in five was administered for less than 10 days before perforation. Obstruction coexisted in only three patients. There were two deaths. Twenty-two patients were treated with resection and diversion, nine patients with resection and drainage, and two with plication only. No relationship between steroid therapy, duration of disease, toxic dilatation, or obstruction with perforation could be established. Resection of the perforated disease segment is necessary when possible. In contradistinction to previous literature, free perforation in Crohn's disease is not as unusual as heretofore believed.

Adolescent

Analysis of dose intensity for chemotherapy in early (stage II) and advanced breast cancer.

In chemotherapy of advanced breast cancer, the dose intensities of regimens containing cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) and cyclophosphamide, doxorubicin, and 5-fluorouracil (CAF) correlate with remission rate. The correlation is even better if dose intensity is calculated from doses actually given instead of from targeted doses. Also, in adjuvant chemotherapy of stage II breast cancer, the dose intensities of CMF-containing regimens correlate with relapse-free survival. The adjuvant trials analyzed included studies containing only 1 or 2 of C, M, or F or with L-phenylalanine mustard (melphalan) instead of C. Three-year relapse-free survival was clearly related to dose intensity whether the analysis was of trials containing all 4 prognostic groups [women less than 50 yr with 1-3 and greater than 3 positive nodes; and those greater than or equal to 50 yr with 1-3 and greater than 3 positive nodes (P less than .00001)] or of trials in which each of these 4 groups were analyzed separately (P less than .005). In multivariate analysis, dose intensity correlated with relapse-free survival (P less than .00001), independent of the number of positive nodes or menopausal status. Randomized trials will be required before we can determine if prospective increases of dose intensity will improve outcome of chemotherapy in breast cancer.

Adult

Injury incidence rates in a paint company on rotating production shifts.

Reports of work accidents and increased absence due to sickness among shift workers have suggested that their work performance and health are adversely affected by interference with the body's normal circadian or biological rhythm. Since the rotating shift is the most disruptive of the work regimens, an investigation was undertaken of the reportable occupational injuries of 1700 paint production and associated employees of one company working only on rotating shift. Their annual accident incidence rates averaged over 10 years were compared to the average annual rate reported by the Department of Labor for the entire United States paint manufacturing industry representing predominately day and non-rotating shift workers. The significance of the hour of the accident incidence rates was tested by chi-square statistics using loglinear models appropriate for null hypotheses that assume no effect due to shift work. The incidence rates of the company studied were lower than those of the U.S. paint industry, suggesting work safety practices uniquely related to the company studied may have predominated. Within the company, however, some time-of-day and circadian effects were indicated by an increased rate of accidents on the night shift, particularly during the last 3 h of the shift.

Accidents, Occupational

Reduction of sympathetic inotropic response after ischemia in dogs. Contributor to stunned myocardium.

Eight open chest dogs underwent 25 min of coronary occlusion to determine whether brief myocardial ischemia disrupts the normal myocardial inotropic response to sympathetic nervous stimulation. If so, this could represent a mechanism contributing to postischemic myocardial dysfunction. Myocardial segment shortening was measured using ultrasonic dimension crystals before and after coronary artery occlusion and reperfusion. Left ansa subclavia stimulation and systemic norepinephrine (NE) infusion were used to test the myocardial inotropic response to neural stimulation and direct exposure to the sympathetic mediator, respectively. Before coronary artery occlusion, base-line preischemic segment shortening (12.5 +/- 1.6%) (SEM) increased during both sympathetic stimulation (20.2 +/- 1.4%) and NE infusion (19.7 +/- 1.1%). The control segment responded similarly. After ischemia and reperfusion there was no significant change in heart rate, aortic or left ventricular pressures, nor changes in control segment shortening. In contrast, shortening in the postischemic segment was markedly reduced compared to baseline (4.1 +/- 2.4%), and no longer responded to sympathetic stimulation (2.4 +/- 2.8%), while responsiveness to systemic NE was maintained (12.9 +/- 2.0%), P less than 0.001, which suggested injury to the sympathetic-neural axis during the period of ischemia. This reduced response to neural stimulation was persistent for up to 2 h after reperfusion. Left atrial or intracoronary infusion of bretylium tosylate, which releases norepinephrine from nerve terminals, resulted in an immediate inotropic response in the postischemic segment, which indicated that total depletion of NE from nerve terminals during the ischemic period had not occurred. Disruption of sympathetic neural responsiveness is likely a component of the mechanism of postischemic myocardial dysfunction whenever there is appreciable sympathetic drive to the heart.

Animals

Occupational exposure to cyclophosphamide.

Several lines of research have demonstrated the risk of occupational exposure of health-care personnel to anticancer drugs. Urine samples from two nurses working in a cancer clinic were analysed for cyclophosphamide (CP) by gas chromatography after they had prepared the drug for treatment. Since the drug might be absorbed through the skin, urine samples from five volunteers were also examined after a solution of CP had been applied topically to the cubital fossa area. Variable quantities of intact CP were identified in samples from the volunteers collected over 24 h, but in most cases the drug was evident only in urine samples given more than 6 h after application. CP was found in several urine samples from the nurses, but the quantities of CP in these samples were not related to the amounts of drug handled. The identity of CP was confirmed by gas-chromatography/mass-spectrometry. CP appeared sooner in the urine samples from the nurses than in those from the volunteers, suggesting a faster route of absorption, perhaps through inhalation of aerosols generated during dissolution of the drug. These findings suggest that the increased levels of mutagenicity observed in urine samples of nurses who worked on oncology wards might have arisen, in part, from metabolites of CP.

Adult

Comparison of muscle and fat wasting in patients suffering from breast and other cancers: an anthropometric study.

An anthropometric study was undertaken to determine muscle and fat areas in 50 cancer patients and 258 control patients suffering from minor conditions, to assess the degree of cachexia in patients with breast cancer, and in patients with other types of cancer. Patients suffering from cancers other than those of the breast showed muscle and fat wasting when compared with matched standard values and when the muscle and fat area measurements were expressed as a percentage of the appropriate mean standard value. Breast cancer patients showed increased muscle and fat area values, irrespective of whether they were in remission, or had progressive disease. This is interesting in view of the strong association between dietary fat intake and breast cancer incidence, and correlates well with present ideas on nutrition and the incidence of breast cancer.

Adipose Tissue

A laboratory evaluation of wipe testing based on lead oxide surface contamination.

Although wipe testing has been used extensively as a measure of surface contamination in industrial hygiene, few scientific studies have been reported to validate the procedure with respect to quantitative recovery, repeatability or methodology. Consequently, a laboratory evaluation of wipe testing with particular attention to the OSHA procedure was undertaken using lead oxide dust as the test contaminant. A dust dispersion system was devised using a Wright dust feeder to produce relatively uniform surface concentrations in an aerosol chamber. Wipe materials included moistened filter paper, commercial paper towels, adhesive paper labels and adhesive tape. The quantitative recovery and repeatability of the wipe procedures were related to surface concentrations and the operational and material variables. Significant improvements in recoveries of up to 90% can be obtained with good repeatability for removable lead oxide dust on non-porous surfaces using moist paper on a fixed test surface area. For porous surfaces, which show significantly lower recovery by all methods, adhesive sampling materials applied at maximum pressure provided an optimum recovery of 77%. The importance of reliable surface contamination measurements in assessing potential health hazards underscores the desirability of improving the demonstrated deficiencies of the OSHA and other wipe sampling procedures.

Air Pollutants, Occupational

Study and models of total lead exposures of battery workers.

In an attempt to establish a more realistic and reliable model for relating environmental exposure measurements to the biological indices of exposure, a study was undertaken to quantify the total sources of lead exposure among lead storage battery workers. In addition to the usual personal and area lead air sampling, quantitative and repeatable measurements of removable lead from work surfaces and the workers' hands and faces were obtained daily for ten consecutive work days in the pasting and battery assembly departments. Mathematical correlations of blood lead and zinc protoporphyrin (ZPP) levels as the dependent variable with the lead exposure sources were derived and demonstrated most strongly as log-log relationships. Statistical analyses by computer programming indicated that the airborne, hand, facial and work surface levels have a high degree of inter-correlation with a very significant positive individual correlation with blood lead levels and a somewhat lower correlation with ZPP. The results suggest that contaminated personal and work surfaces may play a more significant role in toxic occupational and environmental exposures, generally, than had heretofore been demonstrated or suspected.

Adult

The accreditation of academic programs in industrial hygiene.

The American Academy of Industrial Hygiene has initiated a program to accredit academic programs in industrial hygiene. Guidelines, criteria, and procedures to be employed by the Accreditation Committee are summarized, along with a status report of activities currently underway.

Accreditation

Serum amino acids in weight-losing patients with cancer and tuberculosis.

A study of arterial and arterio-venous amino acid concentration differences across the forearm was performed in 19 weight-losing cancer (CWL) patients (9 with lung cancer and 10 with other types of cancer), 8 weight-losing patients with active pulmonary tuberculosis (TWL) and 10 normal controls. Arterial concentrations of many of the amino acids measured were found to be lower in CWL than in TWL patients. In addition, the data suggested a venous excess of amino acids in the CWL patients compared with TWL patients and controls. The increased release of alanine from forearm muscles in the CWL group, together with the low arterial glycogenic amino acid levels, supports the concept of enhanced gluconeogenesis in CWL patients. Low arterial amino acid levels and possible increased release of amino acids from forearm muscle in CWL patients implies enhanced proteolysis with increased central clearance or tumour sequestration of these amino acids, though decreased proteogenesis cannot be excluded in accounting for the venous excesses in this group. Hypocitrullinemia in lung cancer patients was marked, and possible mechanisms to account for this are discussed.

Adult

Occupational dermatitis among hairdressers. A multifactor analysis.

Dermatitis among hairdressers has been recognized as a significant occupational health problem but the occurrence, contributing factors, and control measures have not been comprehensively studied or reported. Consequently, an epidemiologic field study of dermatitis among hairdressers and its relationship to medical history of allergy, frequency of specific product use, sex, and number of years in hairdressing was conducted in the winter of 1982 in four southern New Jersey counties. Work practices and procedures were observed and chemical inventories taken during on-site visits to the participants' beauty salons. The data collected were complied and analyzed using a computerized log-linear statistical procedure. The association between the occurrence of dermatitis and a medically confirmed history of allergy is highly significant (p less than .001) and decreases with increasing numbers of years in hairdressing, indicating perhaps that highly susceptible individuals leave their jobs. There was no significant relationship between dermatitis and the levels of frequency of product use. Means of controlling and preventing occupational dermatitis among hairdressers are discussed. Because of the complexity and diversity of the chemical products used, further research is needed to explore the specific etiological factors of hairdresser's dermatitis.

Dermatitis, Occupational

A review of the health effects of energy conserving materials.

The energy conservation movement has promoted both greater use of insulating materials and the reduction of heat losses by sealing air leaks. The release of volatile or airborne materials from the installation of these building materials under these conditions has resulted in an exacerbated indoor air pollution with the potential for certain health and safety hazards. Consequently, a comparative review of the health and safety hazards, exposure standards, and regulatory action associated with the more commonly used insulating materials with particular respect to current energy conservation measures was undertaken. The materials reviewed included asbestos, urea-formaldehyde foam, polyvinyl chloride, cellulosic insulations, fibrous glass, mineral wool, and vermiculite. Although no longer used, the past installation of asbestos in a friable form is the greatest potential health hazard. The exposure to formaldehyde gas from its release from urea-formaldehyde foam has elicited subjective complaints of sensory irritation and unresolved controversy and regulatory action regarding its toxicity to humans. Lesser health problems have been associated with the more widely used fibrous glass and mineral or rock wools.

Asbestos