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Biomedical subjects

M H Golden

Publications and source records attributed to M H Golden.

At least 73 records · Page 4Linked to original sources
PubMed1988

Active and passive transport of sodium and potassium ions in erythrocytes of severely malnourished Jamaican children.

Erythrocytes of normal and malnourished children, both marasmic and oedematous (kwashiorkor), were equilibrated in standard incubation medium and their ion transport via the Na/K pump and the pathways of passive permeation were measured as unidirectional fluxes of 86Rb (as a congener of K) and 22Na. Cells of children with kwashiorkor exhibited a 65 per cent higher ouabain-sensitive K(Rb) influx ('pump rate') than those of normal or marasmic children. When allowance was made for cytoplasmic Na concentration, the pump rate was slower in younger (12 months and under) normal children than in older children. Judged by the same criterion, cells of older marasmic children also had slower steady-state pump activity. The passive permeation of K through the residual 'leak' pathway (ie, ouabain-and-bumetanide-insensitive influx) and Na permeation (ouabain-and-bumetanide-insensitive Na efflux) were greater in malnourished children than in normal children by a factor of two or more. During treatment for malnutrition, both Na-pump activity and ouabain binding increased rapidly in marasmic children. Passive permeation did not return to normal levels in malnourished children during the period of hospitalization.

Age Factors↗
PubMed1987

The determination of minoxidil in human serum by high-performance liquid chromatography with amperometric detection.

An ion-pairing reversed-phase HPLC assay employing amperometric detection has been developed for the determination of free minoxidil (MNX) in human serum. The drug is isolated from the serum and concentrated by solid phase extraction with a disposable cartridge column containing ethylsilane (C2) bonded phase packing material. The average absolute recovery from serum was 85%. The HPLC separation is performed on a Sperisorb-C(8) column, using n-octanesulphonic acid as the pairing ion. The method exhibits linear behaviour from 0.3 to 100 ng/ml for spiked serum samples. The average daily relative standard deviations of replicate samples at the 0.75 and 2.0 ng/ml levels were 9.6 and 6.4%, respectively. Utilizing a 1 ml sample the limit of detection (S/N > or = 3) was 0.3 ng/ml.

Journal Article↗
PubMed1985

Population dynamics and chemotherapeutic control of Trichuris trichiura infection of children in Jamaica and St. Lucia.

Population dynamical parameters of Trichuris trichiura infections in children were estimated from longitudinal intensity and prevalence data from a population (n = 23) in a children's home in Jamaica. The theoretical predictions of a deterministic model incorporating these parameters were approximated to observed horizontal-age prevalence data from a naturally infected population (n = 203) of children in a St. Lucian village, and a rough estimate of the basic reproductive rate (Ro = 8-10) of T. trichiura obtained. The findings suggest that T. trichiura populations are intrinsically more difficult to control by traditional mass-treatment chemotherapy (eradication requires greater than 91% of the population to be treated every 6 months for greater than 5 years) than are populations of Ascaris, but may be more susceptible to selective chemotherapy programmes which aim to treat only the most heavily infected individuals.

Age Factors↗
PubMed1985

Population distribution of Trichuris trichiura in a community of Jamaican children.

The Trichuris trichiura worm burdens of 23 children living in a Place-of-Safety in Kingston, Jamaica, were assessed by stool collection for more than five days after treatment with mebendazole. This procedure was repeated after a seven-month period of natural re-infection. For both collections the maximum rate of worm expulsion was achieved on the fourth day after starting treatment. The worm population distributions were overdispersed and well described by the negative binomial probability model (k = 0.29) in each case. For any one individual, the number of worms passed on the first expulsion was unrelated, absolutely or relatively, to the number passed on the second. These data suggest that: knowledge of the time dependency of helminth expulsion is essential for the accurate estimation of worm burdens by this method; populations of Trichuris are more highly aggregated than those of Ascaris and may thus be more susceptible to control by selective rather than random chemotherapy; and the inherent predisposition of hosts to infection may be of minor importance in determining the distribution of worms in the population-heavily infected hosts appear no more or less likely to acquire large worm burdens on subsequent exposures.

Child↗
PubMed1985

Sodium azide preservation of faecal specimens for Kato analysis.

The modified Kato technique has the advantages of reproducibility, simplicity and economy: the disadvantage is that it cannot be used in conjunction with traditional faecal preservatives. Sodium azide has been evaluated as a preservative for human faeces for subsequent Kato analysis. More than 400 faecal samples (from normal and malnourished children, and from mixed-age participants in a field survey of the Turks and Caicos Islands) were each mixed with 2-5 mg of sodium azide powder and stored in 2 or 4 ml autoanalyser cups at ambient tropical temperature. At intervals up to 30 weeks, aliquots were prepared for Kato analysis. Trichuris trichiura, Ascaris lumbricoides and Necator americanus eggs were well preserved without degenerative or developmental changes in morphology. Quantitative analyses of 18 samples indicated that the mean egg count/sample did not change significantly after storage for 1, 2, 4, 8, 12 and 16 weeks in preservative. The use of azide preservative extends the applications of the Kato technique to field and clinical studies in which delays may occur between specimen collection and examination. The direct costs of azide preservation are substantially lower than for traditional methods and the preserved specimens are more compact and resistant to leakage.

Ascaris↗
PubMed1983

Whole-body protein turnover and nitrogen balance in young children at intakes of protein and energy in the region of maintenance.

Nitrogen balance and whole-body protein turnover were measured in children aged about one year taking diets which provided 1.7 or 0.7 g milk protein/kg/d at three levels of metabolizable energy, 80, 90 and 100 kcal/kg/d. All the children were in positive nitrogen balance at all levels of energy intake on 1.7 g protein/kg/d. Nitrogen equilibrium was maintained on 0.7 g protein/kg/d when the energy intake exceeded 90 kcal/kg/d, but on 80 kcal/kg/d nitrogen balance was negative. Whole-body protein turnover was measured from the enrichment in urinary ammonia following a continuous infusion of 15N-glycine. The variation between individuals on the same diet was significantly greater than the variation within individuals at different levels of energy intake. For the group as a whole protein synthesis on 1.7 g protein/kg/d was 0.74, 0.75 and 0.87 g N/kg/d on 100, 90 and 80 kcal/kg/d respectively; whereas on 0.7 g protein/kg/d it was 0.37, 0.38 and 0.40 g N/kg/d. These results show that over this range of intakes protein synthesis decreased as dietary protein fell, but tended to increase as energy intake fell.

Ammonia↗
PubMed1982

Protein deficiency, energy deficiency, and the oedema of malnutrition.

The role of dietary protein deficiency in kwashiorkor is uncertain, although it has been shown not to be involved in the famine oedema of adults. A study of six different diets given to 103 children with oedematous malnutrition showed that the rate of loss of oedema was strongly correlated with the dietary energy intake (r = 0.75) but not with the protein intake (r = 0.03). 66 patients given a very-low protein diet (2.5% protein energy) lost oedema as fast as those given five times as much protein. The energy intake above which oedema resolved and below which oedema accumulated was 245-270 KJ/kg/day. Because energy deficiency is not invariably associated with oedema it cannot be the only factor involved, and the necessary dietary component(s) must therefore have been present in surfeit in all the therapeutic diets. This could be potassium together with factors necessary for its retention. The accessory ingredients must be low in foods associated with human and experimental nutritional oedema. It is suggested that protein deficiency is not the cause of the oedema of kwashiorkor and that there is no need to postulate a different pathogenesis for this oedema from starvation oedema of adults.

Adult↗
PubMed1982

Glutamine production rate and its contribution to urinary ammonia in normal man.

1. Glutamine [15N]amide was infused at a steady rate of 33.34 mumol/h into seven male adult volunteers who were in the fed state and normal acid-base status. 2. Plasma glutamine amide N enrichment and urinary ammonia N enrichment rose to a constant rate within 3 h. 3. The glutamine production rate was 51.8 +/- 7.9 mmol/h. 4. The total ammonia excretion rate was 0.87 mmol/h. Of this excreted ammonia 62.6 +/- 9% was derived from the amide N atom of glutamine. 5. The excreted glutamine amide N (0.53 mmol/h) was only 1% of the glutamine production. If half the ammonia formed by the kidney is excreted in urine and half liberated into the renal vein in subjects with normal acid-base status [E. E. Owen & R. R. Robinson (1963) Journal of Clinical Investigation, 42, 263-276], then the kidney accounts for only 2% of glutamine disposal. 6. Whole body protein turnover, measured from the urinary [15N]ammonia enrichment, was 30.3 +/- 7.7 g of N/day (2.8 g of protein day-1 kg-1).

Adult↗
PubMed1981

Plasma zinc, rate of weight gain, and the energy cost of tissue deposition in children recovering from severe malnutrition on a cow's milk or soya protein based diet.

Thirty-four malnourished children were rehabilitated on either a cow's milk or a soya protein based formula diet. The soya diet contained 25% less zinc than the cow's milk diet and 1.33 mmol/l phytic acid. When the marasmic children were given either of these diets they had a dramatic fall in their plasma zinc concentration. Children given the soya formula had an even more profound drop in plasma zinc, to levels associated with acrodermatitis enteropathica. Plasma zinc remained low throughout the phase of rapid weight gain, but rose when a mixed diet was given and the children ceased gaining weight. There was a negative correlation between the rate of weight gain and the plasma zinc concentration, the rate of new tissue synthesis being the predominant modulator of the plasma zinc concentration. The energy cost of tissue deposition was initially low on the cow's milk diet and relatively high on the soya diet. Later, the energy costs rose in the cow's milk fed children. The rate of weight gain was less on the soya diet; however, the appetite, as measured by the ad libitum dietary intakes, did not differ between the diets, or correlate with the plasma zinc concentration. This may be due to the relatively low protein content of the diets used. It is concluded that dietary zinc may limit the rate of weight gain during periods of recovery in body mass and may be a cause for the excessive deposition of adipose tissue.

Animals↗