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Biomedical subjects

M D Mann

Publications and source records attributed to M D Mann.

At least 19 recordsLinked to original sources
PubMed1992

Brain size/body length relations among myomorph rodents.

The relation between cranial volume and body length was examined in 45 species of myomorph rodents to determine how accurately the former can be estimated from the latter. On average within species, cranial capacity was directly proportional to body length (proportional to the cube root of body weight). On average across species, cranial capacity was directly proportional to the square of body length (proportional to the two-thirds power of body weight). Geometric similarity held within species, but the differences in habitus among species within the same genus generated genus slopes that differed from those defined by strict geometric similarity. It was found that cranial capacity could be estimated as accurately from body length as from body weight, and that body length was better if any differences in habitus were involved (because body length is relatively insensitive to habitus). Therefore, body length (or some strong correlate thereof) may serve well as the primary variable in brain paleoallometry.

Animals↗
PubMed1992

Relation between brain and body growth in allied rats.

Cranial volumes were measured from museum specimens of wild-caught and laboratory-born Allied rats from eastern Australia. The relation of these volumes to body weight and body length, and also to age at death in the laboratory-reared sample, was determined. Growth of both brain and body was rapid during the first three postnatal months and slowed markedly over the next month, but appeared to continue at a very slow rate throughout life. In particular, the major surge in brain growth occurred in the first three postnatal weeks. Modified Gompertzian growth functions describe the pattern of growth quite well, though the nature of the data precluded highly sensitive fits. Three features were clear: 1) the rate of slowing of growth was about the same for all variables, 2) growth appeared to continue throughout the life of the animal, and 3) the trajectory of brain growth led that of body growth by about four days. The pattern of growth in Allied rats is similar to that of laboratory rats and probably to those in other murids.

Animals↗
PubMed1979

The age, nutritional status and major diagnoses of outpatients at the Red Cross War Memorial Children's Hospital.

In 1961 a study of the age, sex, race, nutritional status and common diagnoses of children attending the Red Cross War Memorial Children's Hospital in Cape Town during one 12-month period was reported. A similar study was undertaken during two 2-week periods in 1972--1973. Comparison of the studies shows: (i) that a greater number of older children attended the hospital in 1972/1973; (ii) that the proportion of malnourished children whose percentage of expected weight for age was less than 66% had decreased from 8--10% to 5,5--6%; and (iii) that the overall pattern of disease had not changed appreciably, most of the children presenting with minor or preventable conditions.

Age Factors↗
PubMed1979

Sets of neurons in somatic cerebral cortex of the cat and their ontogeny.

The process of set formation is briefly reviewed and five monothetic schemes for classification of neurons in the somatic cerebral cortex are described. Criteria for evaluation of neuronal sets are presented and applied to the five different monothetic classification schemes. Classification by size and distribution of peripheral receptive fields orders existing data on cortical neurons better than classification by possession of an axon in the pyramidal tract, by modality, by lability of receptive field, or by 'lemniscal properties'; however, no monothetic scheme orders all the data. A useful polythetic scheme, using s and m terminology is suggested. The ontogeny of the cerebral cortex is reviewed in detail. It is suggested that sa neurons are Golgi type II neurons while m neurons are Golgi type I neurons. The hypothesis is presented that wide-field or m neurons develop and are recognizable before small-field or sa neurons in ontogeny. Evidence regarding this hypothesis is indirect, often conflicting, but suggestive that the hypothesis may be correct. The idea that m neurons may also be phylogenetically older than sa neurons is presented and shown to be consistent with ontogenetic data and interpretations.

Animals↗
PubMed1977

Kerosene absorption in primates.

Kerosene, labeled with 3H-toluene or 14C-hexadecane, was given to baboons by nasogastric tube after a tracheostomy had been performed. Six hours later the animals were killed and samples of tissues taken for analysis. The radioactive label was recovered from all the tissues analyzed. 3H-toluene appeared to be absorbed and taken up by most tissues to a greater extent than was 14C-hexadecane. No abnormal neurologic signs or behavior was noted in the baboons which were conscious during the study period. It appears that primates absorb kerosene from the gastrointestinal tract, but the volumes are very small and do not cause gross neurologic signs.

Adrenal Glands↗
PubMed1976

Complications of nasojejunal tube feeding.

The frequency and duration of complications were compared in premature babies fed by nasojejunal and nasogastric tubes. Some factors may have weighted the results against the nasojejunal tube-fed group, but this study failed to demonstrate differences in the rate and duration of complications.

Diarrhea, Infantile↗
PubMed1976

Growth and nutrition of uremic piglets.

Piglets aged 6 days were rendered uremic by subtotal nephrectomy and their growth and dietary intakes studied over the next 21 days. Eleven control piglets fed a voluntary intake of a sow's milk substitute (group A), 11 nephrectomized piglets fed a voluntary intake of the same feed (group B), 6 nephrectomized piglets tube fed the same milk (group C), and 11 nephrectomized piglets fed a voluntary intake of a low protein, isocaloric food (group D) were studied. After nephrectomy the piglets had an initial rapid rise in blood urea concentration which had fallen by day 7 and then leveled out around 13 mmol/liter in group B and 8 mmol/liter in group D. After operation control piglets (group A) ate more from day 4 and were larger from day 7 than the nephrectomized piglets (group B). Those piglets tube fed (group C) were of a similar size to the controls but all died between day 7 and day 11 with associated high blood urea concentrations. Piglets fed the low protein, isocaloric feed (group D) were smaller than both the controls and group B. They also ate less food than the controls and those nephrectomized piglets in group B which were on a voluntary intake of the normal feed.

Animals↗
PubMed1975

Potassium retention in acute diarrhoeal disease.

Most children suffering from severe acute diarrhoeal disease had a low total body potassium (TBK) or admission to hospital. TBK fell even lower during the first 5 - 9 days in hospital, and returned to normal levels during the next 8 - 12 days. There was good correlation between potassium retention and stool weight. An increase in the potassium intake had little effect on the rate of potassium repletion.

Acute Disease↗
PubMed1975

Bicarbonate excretion in kwashiorkor.

Children with kwashiorkor have an impairment of bicarbonate excretion which may result in the inappropriate production of acid urine in the presence of systemic alkalosis. This defect has resolved after 2 weeks of treatment.

Bicarbonates↗
PubMed1975

Total body potassium, acid-base status and serum electrolytes in acute diarrhoeal disease.

Total body potassium (TBK), acid-base status and serum electrolyte concentrations were measured in 49 children suffering from acute diarrhoeal disease, on admission and after rehydration. The TBK was usually low and the lowest values were found in those with the lowest pH. There was no relationship between TBK and serum sodium or potassium concentrations. Hyponatraemia was common as would be expected in a series containing many underweight children.

Acid-Base Equilibrium↗
PubMed1975

Total body potassium, potassium retention and potassium intake in protein energy malnutrition.

The total body potassium (TBK) and potassium retention were measured during the early stages of recovery of malnourished children on three levels of potassium intake. A potassium intake of 2 mEq/kg/day resulted in significantly greater potassium retention than one of 3 mEq/kg/day. A higher level of intake (15 mEq/kg/day) did not result in an absolute increase in potassium retention and is not recommended because of its theoretical dangers, although it may have stimulated an increase in potassium capacity.

Child, Preschool↗
PubMed1975

Total body potassium and serum electrolyte concentrations in protein energy malnutrition.

The total body potassium (TBK) and serum electrolyte concentrations of malnourished children in Cape Town are similar to those in Jamaica. The TBK is almost always low and hyponatraemia is common, but there was no relationship between the TBK and serum Na and K concentrations. These abnormalities, particularly a very low TBK, appear to influence the prognosis. The expression of the observed TBK as a percentage of the expected value for a normal child, of the same weight and height, appears to be a useful index of the severity of the total body potassium deficit.

Child, Preschool↗
PubMed1975

Early insulin release and its response to potassium supplementation in protein-calorie malnutrition.

Early insulin release after oral glucose is absent in protein-calorie malnutrition (PCM). There is an increase of the insulin-glucose ratio at 10 and 15 min induced by potassium supplementation compared to a similar group receiving an identical diet without supplementary potassium. This suggests that impaired insulin secretion in PMC is in part due to a potassium mediated disturbance of insulin release.

Blood Glucose↗