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Biomedical subjects

R Green

Publications and source records attributed to R Green.

At least 451 records · Page 25Linked to original sources
PubMed1979

Free-flow reabsorption of glucose, sodium, osmoles and water in rat proximal convoluted tubule.

1. Reabsorption of glucose, sodium, total solute (osmoles) and water in the rat proximal tubule (pars convoluta) were studied by free-flow micropuncture at normal (saline-infused), suppressed (saline with phlorizin) and elevated (glucose infusion) glucose reabsorption rates. 2. Phlorizin completely inhibited net glucose reabsorption, approximately halved reabsorption of sodium, total solutes and water, and reduced single nephron glomerular filtration rate (SNGFR). 3. In saline and glucose-infused groups, there were no significant differences between SNGFR nor between reabsorptions (fractional and absolute) of either sodium, total solute or water, which were uniformly distributed along segments assessible to micropuncture. 4. Glucose reabsorptive capacity existed along the entire pars convoluta, with highest reabsorptive rates in convolutions closest to the glomerulus (in saline-infused rats, 90% fractional reabsorption at 2 mm, over 95% at end pars convoluta; in glucose-infused rats, 55 and 90%, respectively). 5. In saline and glucose infused rats, a significant correlation existed between net glucose and sodium reabsorption, but the regression slopes differed and correlations became non-significant when the reabsorptive fluxes were factored by SNGFR. 6. For all groups, the majority of tubular fluid (TF) concentrations of osmoles and sodium were lower than those in plasma (over-all mean TFosm)Posm = 0.973 +/- 0.004, P less than 0.001; TFNa /PNa = 0.964 +/- 0.005, P less than 0.001). 7. Correspondingly, calculated osmolal and sodium concentrations in the reabsorbate were greater than those in plasma, and were significantly correlated with distance to puncture site with maximal values in the most proximal convolutions (for osmolality, approximately +79 m-osmole kg-1 water at 1 mm).

Absorption↗
PubMed1978

Increased erythrocytic diphosphoglycerate in megaloblastic anaemia. A compensatory mechanism?

The levels of erythrocytic 2,3-diphosphoglyceric acid (2,3-DPG) in a group of patients with megaloblastic anaemia were compared with levels in an iron-deficient subject. The megaloblastic cells appeared to have 2 mumol more 2,3-DPG per g Hb than the iron-deficient cells, at the average haemoglobin level found in the megaloblastic group. The anticipated adaptive decrease in the oxygen affinity of the blood was not apparent when the relationship of P50 (7,4) to haemoglobin level was examined. This was shown to be due to a decreased mean corpuscular haemoglobin concentration (MCHC), which counteracted the effect of the increased 2,3-DPG.

Anemia, Hypochromic↗
PubMed1978

Protein energy malnutrition and nutritional anaemia in preschool children in rural KwaZulu.

The prevalence of protein energy malnutrition (PEM) and nutritional anaemia was investigated in 392 black children, aged 13--60 months, living in a poor rural area. Breast feeding was practised extensively in the population (median duration 14 months). The overall prevalence of PEM was 16,4%, but severe PEM occurred in only 2,7% of the children. Anaemia was present in 6,7% of children, and was almost invariably associated with iron deficiency. Biochemical evidence of iron, folate and vitamin B12 deficiency was detected in 36%, 14,8%, and 0,3% of children respectively. Anaemia was almost confined to the 1-year-old group, but biochemical evidence of iron deficiency, while highest in this age group, continued into the 2-4-year age group. No relationship was found between ecological factors such as income, educational status, etc. and any of the anthropometric, biochemical or haematological variables. The prevalence of PEM and anaemia in these poor rural children is lower than that of a comparable group of underprivileged urban children, thus emphasizing that city slum conditions are producing considerable nutritional problems in their wake. It is of importance to investigate further why some children who are severely deprived in many ways do not necessarily manifest a proportional degree of nutritional deprivation.

Black or African American↗
PubMed1978

Methods for establishing a working immunoradiometric assay for serum ferritin.

The two-site immunoradiometric assay for measurement of serum ferritin requires purified human ferritin and an avid high-titer antihuman ferritin antibody. Some of the antibody is radioiodinated following purification by immunoadsorption. All methods for preparation of these materials for the assay are described in minute detail. Performance of the assay itself and calculation of results are also described, and attention is drawn to several potential pitfalls. Adherence to these detailed descriptions will help to eliminate difficulties experienced by centers wishing to establish their own working serum ferritin assay.

Adolescent↗
PubMed1978

Closure of gastrojejunostomy for the relief of post-vagotomy symptoms.

When dumping, diarrhoea or bile vomiting follows vagotomy and gastrojejunostomy, simple closure of the stoma, without alternative drainage, has been performed in 19 patients. Thirteen patients, 5 with truncal, 7 with selective and 1 with proximal gastric vagotomy, have been followed up for 1-6 years. Five were completely relieved of symptoms, 7 improved and there was only 1 complete failure. Bile vomiting was more often relieved than dumping or diarrhoea. The procedure is safe and significant gastric retention does not occur provided that at least one year is allowed to elaspse after the primary operation.

Adult↗
PubMed1978

Roux diversion for bile reflux following gastric surgery.

Regurgitation of bile into the stomach after gastric surgery often causes severe and distressing symptoms, though the onset may be delayed for some years. We have used a Roux loop diversion as a secondary procedure for bile reflux in 36 patients, making the anastomosis from 18 to 40 cm below the stomach. There were no deaths and the clinical results were good in 20 of 27 patients followed up from 1 to 10 years. Vagotomy was omitted in 13 patients, 2 of whom subsequently developed jejunal ulceration. One patient developed an unexplained gastric ulcer and 2 operations failed because the loop was too short. The optimum length may well be 40 cm and vagotomy should be added in all cases. In 3 patients with associated dumping the upper 10 cm of the Roux loop was reversed.

Adult↗
PubMed1978

Rapid assay for measurement of serum ferritin.

The authors present a rapid modification of the tube immunoradiometric assay for serum ferritin quantitation. The method involves gentle rotatory mixing of the tube contents at ambient temperature and can be performed in a few hours. Variables affecting different stages of the assay were systematically investigated. The performance characteristics of the shortened assay in terms of reproducibility, sensitivity and recovery were then validated. Results with this method correlate well with those obtained by the conventional assay.

Ferritins↗
PubMed1978

Antepartum stress cardiotocography using buccal oxytocin.

The use of buccal pitocin in the performance of stressed antenatal cardiotocography was studied. Sixty-three tests were performed on 40 patients. All the patients were followed through labour and delivery. The results were evaluated and compared with those where an intravenous oxytocin infusion was used. Buccal pitocin produced comparable uterine contractions to those obtained by intravenous oxytocin, with similar test results. The avoidance of venepuncture and infusion was a positive advantage of this method of applying the stress.

Administration, Oral↗
PubMed1978

Effects of phlorizin on glucose, water and sodium handling by the rat kidney.

1. The effect of phlorizin on glucose, water and sodium handling by the kidney in anaesthetized rats was investigated, using clearance techniques, during infusion of saline (200 microliter min-1) or saline to which either low (0.1 mumole kg body weight-1 ml.-1) doses of phlorizin had been added. 2. Phlorizin increased the absolute and fractional excretion of glucose, urine osmolality and negative free water clearance; and reduced urine flow rate, glomerular filtration rate (GFR), absolute and fractional excretion of sodium, absolute excretion of sodium, absolute excretion of potassium and absolute and fractional rates of glucose reabsorption. 3. The data indicate that phlorizin has sites of action and effects additional to those on glucose transport in the proximal tubule. 4. Within each series there was a positive correlation between sodium and glucose reabsorption; but the rate of glucose reabsorption was different between each series even though the sodium reabsorption was not. 5. It is suggested that since both sodium and glucose reabsorption correlate with GFR, they may be related via GFR. 6. The data indicate that for the whole kidney any effect of glucose on sodium transport is small relative to total renal handling of sodium.

Absorption↗
PubMed1978

Effects of glucose on water and sodium reabsorption in the proximal convoluted tubule of rat kidney.

1. The effects of glucose on sodium and water reabsorption by rat renal proximal tubules was investigated by in situ microperfusion of segments of proximal tubules with solutions containing glucose or no glucose, with and without phlorizin. 2. Absence of glucose did not significantly alter net water flux. Sodium flux was reduced by about 10% but this was not statistically significant. 3. In the absence of glucose in the perfusion fluid net secretion of glucose occurred. 4. Phlorizin reduced either net reabsorption or net secretion of glucose; and net water flux. 5. The data suggest that in later parts of the proximal convoluted tubule some sodium may be co-transported with glucose, but that this represents only a small fraction of the total sodium reabsorption. 6. It is suggested that the glucose carrier is reversible and in appropriate circumstances could cause glucose secretion. 7. Although phlorizin alters net water flux the underlying mechanisms are not clear. 8. The calculated osmolality of the reabsorbate was significantly greater than the perfusate osmolality and greater than plasma osmolality although this was not quite significant statistically.

Absorption↗
PubMed1978

Sexual identity of 37 children raised by homosexual or transsexual parents.

The author reports on 37 children who are being raised by female homosexuals or by parents who have changed sex (transsexuals): 21 by female homosexuals, 7 by male-to-female transsexuals, and 9 by female-to-male transsexuals. The children range in age from 3 to 20 years (mean = 9.3) and have lived in the sexually atypical households for 1-16 years (mean = 4.9). Thirty-six of the children report or recall childhood toy, game, clothing, and peer group preferences that are typical for their sex. The 13 older children who report erotic fantasies or overt sexual behaviors are all heterosexually oriented.

Adolescent↗