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Biomedical subjects

M Nelson

Publications and source records attributed to M Nelson.

At least 397 records · Page 22Linked to original sources
PubMed1985

Seasonal variations in dietary iodine intake and thyrotoxicosis.

Food composition tables were used to estimate the iodine intake of 105 men and 112 women living in Cambridge who completed 7-day semi-weighed records of food consumption. Intakes in men ranged from 195 micrograms per day in summer to 306 micrograms in winter, and in women from 126 micrograms to 236 micrograms. Seasonal variations in intake were mainly due to seasonal differences in the iodine content of milk which varies directly in relation to farming practices. The authors speculate that a spring-summer peak in thyrotoxicosis incidence in Britain may be causally related to the high milk iodine levels in winter.

Adolescent↗
PubMed1985

Stimulation of proliferation in mixed cultures of mouse tumor cells and nonimmune peritoneal cells. I. Occurrence of stimulation and cyclical variation in tumor cell activity.

Mixtures of mouse tumor cells and resident peritoneal cells (PC) from nonimmune mice frequently incorporated [methyl-3H]thymidine [( 3H]dThd) in culture to a far greater extent than did either cell population alone. With PC-to-tumor cell ratios of 10:1, stimulation indices of up to 21 were recorded. Syngeneic, semisyngeneic, and allogeneic mixtures were active. PC elicited by thioglycollate or proteose-peptone could participate in the reaction. PC from mice injected with Corynebacterium parvum also could do so, provided they were precultured for 48 hours. Normal mouse spleen cells and fibroblasts and human Chang cells were inactive. There was considerable variation between experiments in the extent of stimulation observed, even with the same tumor. When tumors were cloned in vitro, freshly isolated clones differed widely in the extent of stimulation. Individual clones studied over a period of time varied markedly and cyclically in the degree of stimulation they exhibited in mixed cultures. This variation appeared to be unrelated to the density of the cultures from which the clones were obtained, to the base-line incorporation of [3H]dThd by tumor cells alone, or to the frequency of passage in vitro. It is suggested that the cyclical variation may be related to the generation of variant cells, which could be important in tumor progression and metastasis.

Animals↗
PubMed1985

Stimulation of proliferation in mixed cultures of mouse tumor cells and nonimmune peritoneal cells. II. Stimulation of tumor cells by macrophages and of lymphocytes by a tumor cell product.

Stimulation of [methyl-3H]thymidine incorporation in mixed cultures of mouse peritoneal cells (PC) and tumor cells required a large adherent PC. Flow cytometric analysis, as well as autoradiography, showed that the stimulation involved increased proliferation of tumor cells. The stimulation required contact between tumor and PC; it was partly inhibited by Trasylol (aprotinin) and potentiated by dexamethasone. In addition, there was minor stimulation of PC by a soluble product of tumor cells; this stimulation was not affected by Trasylol or dexamethasone. It is suggested that macrophages can stimulate tumor cell proliferation and that such stimulation may be an important factor in host-tumor relationships.

Animals↗
PubMed1985

Successful tumour immunotherapy: possible role of antibodies to anti-inflammatory factors produced by neoplasms.

Phenol-saline tumour extracts, active in the immunotherapy of bovine ocular squamous cell carcinoma (BOSCC), were used to immunize mice. The immunized mice became resistant to the depression of delayed type hypersensitivity (DTH) reactions by products of BOSCC cells or cultured mouse or rat tumour cells. They also showed partial resistance to the growth of an unrelated tumour. Monoclonal antibodies to a type C retrovirus protein, p15E, also induced resistance to the depression of DTH by products of BOSCC and mouse tumours. It is suggested that successful immunotherapy of BOSCC is associated with the induction of resistance to anti-inflammatory or immunosuppressive tumour cell products, allowing the operation of host defences, and that these products share antigenic determinants with a retrovirus protein.

Animals↗
PubMed1985

An abbreviated food table using food groups for the calculation of energy, protein and fat intake.

A method of estimating the energy, protein and fat composition of diets is described, based on 84 food groups. Data from 3 dietary studies are used to compare intake calculated using the food groups and detailed food composition tables, with analyses of duplicate diets. For even small groups of people the mean differences and correlation coefficients between calculated and analysed results are similar for both methods of calculation. This approach could be used as a rapid coding method, or where skilled manpower is not available.

Adult↗
PubMed1984

Alteration of apparent restriction endonuclease recognition specificities by DNA methylases.

An in vitro method of altering the apparent cleavage specificities of restriction endonucleases was developed using DNA modification methylases. This method was used to reduce the number of cleavage sites for 34 restriction endonucleases. In particular, single-site cleavages were achieved for Nhe I in Adeno-2 DNA and for Acc I and Hinc II in pBR322 DNA by specifically methylating all but one recognition sequence.

Base Composition↗
PubMed1984

CPR instruction: modular versus lecture course.

A randomized prospective study was done to examine long-term cardiopulmonary resuscitation (CPR) cognitive and motor skills retention and to compare the "self-taught" modular course with the standard lecture course. Both cognitive and motor skills were tested at one-, two- and four-year intervals after the initial course. Approximately half the students in both the modular and standard lecture courses also took a refresher course after one year. While there was no significant difference (P greater than .05) in retention based on the method of teaching (modular vs lecture course), students who took the refresher course after one year performed significantly better (P less than .01) at the two-year interval. Results four years after the initial CPR course (three years after the refresher course) were uniformly poor in both groups. Only three of 104 students were able to meet American Heart Association standards for the performance of CPR. Refresher courses are vital if CPR is to be performed effectively and competently. They should be available on a continuing basis with self-taught courses providing a good alternative to the formal didactic course as a means of providing instruction.

Educational Measurement↗
PubMed1984

Dyskeratosis congenita. Haematologic, cytogenetic, and dermatologic studies.

In a family of 5 boys and 6 girls, 3 brothers have clinical dyskeratosis congenita. Teeth from 2 of the patients were taurodent , and mineral density of the enamel was significantly different from normal. The haematopoietic marrow was hypocellular and there was striking prominence of plasma cells having normal morphology; no granulomata were demonstrated. The decreased erythroid precursors in the marrow correlated with quantitatively reduced erythropoiesis demonstrated on ferrokinetic studies. Recurrent infections occurred but could not be related to neutropenia, and granulocytes and monocytes retained normal function. No abnormality was demonstrated in humoral or cellular immune mechanisms. While superficially similar, dyskeratosis congenita and Fanconi's anaemia are genetically distinct, being X-linked in the former and inherited as an autosomal recessive in the latter.

Adolescent↗
PubMed1984

Dietary fibre and acute appendicitis: a case-control study.

In order to investigate the hypothesis that low dietary-fibre intake is a cause of acute appendicitis the diets of 30 children who had had appendicitis were compared with those of 55 age-sex matched controls, using a 7-day weighed food record. Although there were no statistically significant differences the average daily intake of cereal fibre was lower in the cases than the controls, giving limited support to reduced cereal fibre intake acting as a determinant of appendicitis. Low water intake may also be a causative influence. There is some evidence that infection and a familial predisposition may increase susceptibility to the disease.

Adolescent↗
PubMed1984

Diet and renal stones: a case-control study.

The diets of 51 men with renal stones were compared with those of 94 age-matched controls, using a measured record of all food and drink consumed during 4 days. The mean intakes of three nutrients suspected in the aetiology of renal stones, animal protein, refined carbohydrate (sugar) and dietary fibre, were similar for both cases and controls. However, the cases had a higher intake of ascorbic acid. A greater proportion of cases had low fluid intakes or took no exercise in their leisure time.

Adult↗
PubMed1984

Parental behavior and the availability of foods among undernourished inner-city children.

This study was designed to identify differences in parental behaviors and the availability of food between undernourished and well-nourished inner-city children of early school age. Children with a constellation of measurements of height below the 25th percentile, midarm muscle circumference below the 50th percentile, and hemoglobin concentration below 11.5 g/dL were considered undernourished. These children were matched with controls having measurements above these levels. The homes of all children were investigated. Families of undernourished children were found to have significantly less variety of nutritious foods requiring preparation by an adult available in the home (P less than .01), to have greater variety of convenience foods of low nutritional value (P less than .01), and to prefer fewer vegetables (P less than .04) and dairy products (P less than .01). The Polansky Child Level of Living Scale showed that mothers of undernourished children were less likely to prepare meals regularly for their children (P less than .05) and that they were less effective in providing general parental support to their children (P less than .03).

Adult↗
PubMed1983

Lymphokine-like products of cultured tumour cells.

Supernatants from cultures of rat and guinea-pig tumour cells, guinea-pig fibroblasts and kidney cells, but not rat fibroblasts, inhibited the migration of peritoneal exudate macrophages in vitro. The inhibitory activity in tumour-cell supernatants differed from that of lymphokine in being heat stable (60 degrees, 3 hr) and dialysable, not inhibited by fucose and, in the case of guinea-pig line 1 tumour, not absorbed by an anti-lymphokine immunoabsorbent. Rat lymphokine and supernatants from four cultured rat tumours and, to a lesser extent, fibroblasts induced procoagulant activity in rat peritoneal exudate macrophages. The tumour procoagulant-inducing activity was heat stable and non-dialysable. Direct procoagulant activity was also found in rat lymphokine, fibroblast and tumour culture supernatants. This activity was partly or completely heat-labile but was non-dialysable.

Animals↗
PubMed1983

The nutritive contribution of school dinners and other mid-day meals to the diets of schoolchildren.

In a dietary study of 112 Cambridge families, 191 primary and secondary school children kept 7-day records of measured food consumption. Of 955 weekday lunches recorded, 533 (56 per cent) were school dinners. School dinners provided less than one quarter of the recommended daily amount (RDA) for energy, iron and riboflavin, and less than one third of the RDA for protein, calcium, thiamin and ascorbic acid. School dinners provided a smaller proportion of a day's nutrient intake than did other mid-day meals. Total energy intakes were lower on school-dinner days than on other week-days. Children from lower income families had larger school dinners and obtained a larger proportion of their daily nutrient intake from school dinners than did children from higher income families. School dinners played their most important nutritional role in the lower income families.

Adolescent↗
PubMed1982

Effects of tumour cell culture supernatants on some biochemical activities of macrophages.

The following enzyme activities were measured in cell lysates and supernatants from mouse peritoneal macrophages incubated with products of cultured tumour and other cells: acid phosphatase, beta-D-glucuronidase, N-acetyl-D-glucosaminidase, muramidase (lysozyme), lactic dehydrogenase (supernatant only) and plasminogen activator (supernatant only). There were no noteworthy changes in enzyme activities. Hydrogen peroxide production by appropriately stimulated mouse and/or guinea-pig peritoneal exudate macrophages was variably inhibited by supernatants from some tumour cells and some normal cells. Changes in these biochemical activities of macrophages do not appear to be closely related to the anti-inflammatory activity of tumour cell products.

Animals↗
PubMed1982

A first aid and CPR course for first-year medical students.

A 24-hour course in first aid and cardiopulmonary resuscitation (CPR) has been developed for the first-year medical students at the Mount Sinai School of Medicine. The objective of the course was to train students to handle common emergencies out of a hospital setting and with no special equipment. It was expected that students would become competent to perform CPR at a level equal to or better than that required by the American Red Cross (ARC) for certification. In the past three years approximately 99% of each first-year class has been certified. The majority of the course is taught by medical students who are certified ARC Instructors in Advanced First Aid and Emergency Care and CPR.

Education, Medical, Undergraduate↗