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R Whitehead

Publications and source records attributed to R Whitehead.

At least 19 recordsLinked to original sources
PubMed1992

Video image analysis of AgNOR distribution in the normal and adenomatous colorectum.

The nucleolar organizer regions (AgNORs) have been studied by video image analysis in the normal colorectum and in adenomas arising there. Total AgNOR area was measured in conjunction with the total area of nuclei and expressed as a ratio. AgNORs are found to predominate in the proliferative regions of the normal mucosal crypt, and the ratio of AgNOR to nuclear area proved significantly greater in the normal colon than in the rectum and far greater in colorectal adenomas. Further, there is a significant difference between the ratio in tubular as opposed to villous patterns of adenomatous growth in the colon but not in the rectum. When classified according to their degree of dysplasia, adenomas in the rectum exhibit a significantly higher ratio of AgNOR to nuclear area as the degree of dysplasia increases in severity. This correlation is not shown in the colon.

Adenoma↗
PubMed1992

Whole body protein metabolism and resting energy expenditure in pregnant Gambian women.

Whole body protein metabolism and resting energy expenditure (REE) were measured at 11, 23, and 33 wk of pregnancy in nine pregnant (not malnourished) Gambian women and in eight matched nonpregnant nonlactating (NPNL) matched controls. Rates of whole body nitrogen flux, protein synthesis, and protein breakdown were determined in the fed state from the level of isotope enrichment of urinary urea and ammonia during a period of 9 h after a single oral dose of [15N]glycine. At regular intervals, REE was measured by indirect calorimetry (hood system). Based on the arithmetic end-product average of values obtained with urea and ammonia, a significant increase in whole body protein synthesis was observed during the second trimester (5.8 +/- 0.4 g.kg-1.day-1) relative to values obtained both for the NPNL controls (4.5 +/- 0.3 g.kg-1.day-1) and those during the first trimester (4.7 +/- 0.3 g.kg-1.day-1). There was a significant rise in REE during the third trimester both in the preprandial and postprandial states. No correlation was found between REE after meal ingestion and the rate of whole body protein synthesis.

Adult↗
PubMed1992

Effect of malaria and fever on energy metabolism in Gambian children.

The aim of the present study was to measure the changes in resting energy expenditure (REE) induced by malaria and to assess to what extent they are related to fever and nutritional status. The REE of 19 Gambian children (mean age +/- SEM, 9 +/- 1 y; weight, 24 +/- 2 kg; expected weight for height 86 +/- 1%) were measured with a hood system at repeated intervals at the onset of malaria crisis (test A), 3 to 4 d after therapy (test B), and 14 to 21 d later (test C). Axillary temperature averaged 39.2 +/- 0.1, 36.6 +/- 0.1, and 36.7 +/- 0.1 degrees C in the tests A, B, and C, respectively. REE in test A was significantly higher than REE in test B (223 +/- 10 versus 174 +/- 8 kJ/kg.d, p less than 0.0001), but in test C (169 +/- 8 kJ/kg.d), it did not differ from that observed in test B. The percentage of increase in REE was significantly correlated with the difference in axillary temperature (r = 0.46, p less than 0.05); the slope of the regression line indicated an increase of 6.9% in REE/degree C of fever. Furthermore, the individual increase in REE/degree C was correlated to the percentage of weight for height of the children (r = 0.54, p less than 0.05), indicating that the child's nutritional status influences the magnitude of the hypermetabolism due to fever. We concluded that Gambian children suffering from an acute episode of malaria have an increase in REE averaging 30%; however, REE promptly returns to baseline value a few days after the beginning of therapy.

Adolescent↗
PubMed1992

Anabolic steroid use among adolescents in a rural state.

BACKGROUND: Anabolic-androgenic steroid use is an increasing problem among high school students. Previous reports have been mainly from metropolitan areas. METHODS: We report the first study of anabolic-androgenic steroid use to concentrate on rural communities. The study was conducted using an anonymous survey of a random sample of male high school students (N = 3900) in grades 10 through 12 encompassing 31 high schools in a predominantly rural state. RESULTS: Two-hundred five (5.3%) students reported using steroids. The prevalence of illicit drug use was significantly higher (P < .05) in steroid users (74%) than in nonusers (31%) (P < .001). The association was between anabolic-androgenic steroid use and illicit drug use rather than between sports participation of any type and illicit drug use (P > .2). Comparison of the prevalence of illicit drug use among athletic (63.2%) and nonathletic (36.8%) steroid users found no significant difference. Findings were similar with cigarette use. There was no difference in the rate of steroid use by school enrollment (69 to 1495) or by city population size (< 200 to 64,000). The predominant reason for steroid use was to improve appearance (43%). CONCLUSIONS: This study found the prevalence of steroid use throughout a predominantly rural state to be similar to that found by previous studies conducted in metropolitan areas; prevalence was not affected by city or school size. Steroid use was closely associated with illicit drug and cigarette use, a new finding that deserves further examination.

Adolescent↗
PubMed1992

Postprandial thermogenesis in lactating and non-lactating women from The Gambia.

Postprandial thermogenesis was assessed by indirect calorimetry in 32 Gambian women classified into three groups as follows: 12 non-pregnant non-lactating and 10 lactating women studied during the dry season and 10 lactating women studied during the rainy season. The test meal consisted of a typical Gambian breakfast and its energy content corresponded to 30% of the individual's resting metabolic rate (RMR)/24 h. During the dry season, the postprandial thermogenesis of the lactating women averaged 6.0 +/- 0.4% of the test meal energy content and was similar to that observed in the non-pregnant non-lactating women studied during the same season (5.8 +/- 0.3%). In contrast, the postprandial thermogenesis of lactating women studied during the rainy, nutritionally unfavourable season was found to be significantly lower (4.9 +/- 0.5%). There was no significant difference in the pre- and postprandial respiratory quotients among groups. This leads to the conclusion that lactation does not alter the thermogenic response to food and that the reduction in postprandial thermogenesis observed in lactating women during the wet season constitutes an adaptive response to energy deficit allowing a saving of energy in periods of food restriction.

Adolescent↗
PubMed1991

Seasonal changes in 24-h and basal energy expenditures in rural Gambian men as measured in a respiration chamber.

Adaptation of 24-h energy expenditure (24-h EE) to seasonal variations in food availability was studied, by using a respiration chamber, in 18 rural Gambian men on three occasions: period 1--at the end of the rainy season, which is characterized by low food availability; period 2--during the nutritionally favorable dry season; and period 3--at the onset of the following rainy season. From periods 1 to 2 body weight increased by 2.8 +/- 0.4 kg, and a rise in 24-h EE was observed (from 8556 +/- 212 kJ/d to 9166 +/- 224 kJ/d), which was correlated to weight change (r = 0.73, P less than 0.001). During period 3, 24-h EE averaged 8740 +/- 194 kJ/d. Diet-induced thermogenesis increased significantly from periods 1 to 2 (5.9 +/- 0.5% to 8.2 +/- 0.8%) and subsequently decreased to 3.6 +/- 0.6% during period 3. In rural Gambian men, metabolic adaptations in response to seasonal changes in food availability are reflected by a decrease in body weight, mainly manifested by a loss of fat-free mass accompanied by a decreased 24-h EE and a lowered diet-induced thermogenesis.

Adult↗
PubMed1991

A new procedure to assess the energy requirements of lactation in Gambian women.

The combined 24-h energy expenditure (24-h EE) of mother and child was measured with a respiratory chamber (indirect calorimeter) in a group of 16 lactating Gambian women and was compared with that of a control group of 16 nonpregnant, nonlactating (NPNL) Gambian women. Breast-milk production (738 +/- 47 g/d: mean +/- SE) was adequate to allow a normal rate of growth of their 2-mo-old babies (28.0 +/- 2.4 g/d). The combined 24-h EE (mother and child) was higher (8381 +/- 180 kJ/d. P less than 0.001) than that of NPNL women (6092 +/- 121 kJ/d). Two-thirds of this differences could be attributed to the child's EE and one-third to a greater spontaneous physical activity of lactating women. The energy retained by the child for growth in conjunction with the calorimetric measurements allowed the calculation of the extra energy requirements for lactation, which were found to be 2100 kJ/d. These results confirm the values of the current dietary recommendations for lactation, based on the energy cost of milk production.

Adult↗
PubMed1991

Stimulation by human chorionic gonadotropin of prostaglandin synthesis by early human placental tissue.

Successful establishment of pregnancy is dependent on inhibition of clotting and suppression of the maternal immune response at the feto-maternal interface. Early human placental production of prostacyclin (PGI2) and prostaglandin E2 (PGE2) may be important in this process. To examine the possible role of these PGs, we studied PGE and 6-keto-PGF1 alpha (stable metabolite of PGI2) synthesis in human placental (9-17 weeks gestation) organ cultures, and monolayer cultures of purified trophoblasts. PGE2 appeared to be the major protanoid formed. Other arachidonic acid metabolites identified in placental organ culture were 6-keto-PGF1 alpha, thromboxane B2, PGF2 alpha, leukotriene B4, 5(S)-hydroxyeicosatetraenoic acid (5-HETE), 12-HETE, and 15-HETE. The synthesis of PGE and 6-keto-PGF1 alpha altered with gestation and was maximal in the younger placentas. Arachidonic acid (33 microM) stimulated and indomethacin (28 microM) inhibited PG production. hCG, including physiological concentrations, stimulated PGE and 6-keto-PGF1 alpha synthesis in placental organ cultures. This effect was most striking in the 9-12 week placentas, compared to 15-17 week placentas. A similar hCG-induced stimulation of PGE production occurred in monolayer cultures of trophoblasts. The addition of TSH, FSH, and LH indicated that this effect was specific for hCG. These data suggest that hCG may have a biological role in the regulation of PG synthesis in early human placenta.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Is human lactation a particularly efficient process?

The recommended dietary allowances of many expert committees (UK DHSS 1979, FAO/WHO/UNU 1985, USA NRC 1989) have set out the extra energy requirements necessary to support lactation on the basis of an efficiency of 80 per cent for human milk production. The metabolic efficiency of milk synthesis can be derived from the measurements of resting energy expenditure in lactating women and in a matched control group of non-pregnant non-lactating women. The results of the present study in Gambian women, as well as a review of human studies on energy expenditure during lactation performed in different countries, suggest an efficiency of human milk synthesis greater than the value currently used by expert committees. We propose that an average figure of 95 per cent would be more appropriate to calculate the energy cost of human lactation.

Adult↗
PubMed1990

Twenty-four-hour energy expenditure and basal metabolic rate measured in a whole-body indirect calorimeter in Gambian men.

By use of a respiration chamber, 24-hour energy expenditure (EE), diet-induced thermogenesis (DIT), and basal and sleeping EE were measured in 20 young rural Gambian men during the "hungry" season (weight, 60.8 +/- 1.4 kg) and in a group of 16 European men matched for body composition (weight, 66.9 +/- 1.9 kg). The 24-h EE was lower in Gambian than in European men (2047 +/- 46 vs 2635 +/- 74 kcal/d, p less than 0.001, respectively). Basal EE and sleeping EE were also lower in Gambian than in European men (1.05 +/- 0.02 vs 1.25 +/- 0.02 kcal/min and 1.0 +/- 0.02 vs 1.18 +/- 0.02 kcal/min, p less than 0.01, respectively). DIT was blunted in Gambian compared with European men (6.3 +/- 0.6% vs 12.1 +/- 0.5%, p less than 0.001 respectively). The net efficiency of walking was greater in Gambian than in European men (23.2 +/- 0.3% vs 20.1 +/- 0.4%, p less than 0.001, respectively). A low basal and sleeping EE, a reduced DIT, and a high work efficiency are important energy-sparing mechanisms in Gambian men, which allow them to cope with a marginal level of dietary intake during the hungry season.

Adult↗
PubMed1989

Morphometric analysis of nuclear features, ploidy status, and staging in rectal carcinoma.

Recently, several flow cytometric studies have shown that the nuclear DNA content in colorectal carcinoma gives prognostic information which is independent of that provided by the histological characteristics of the tumour. In this study the nuclear DNA content and nuclear morphology of 39 cases of surgically resected rectal adenocarcinoma were measured in Feulgen-stained histological sections by video image analysis and 97 per cent were aneuploid. Dukes' stage correlated better with the morphometric data than did other classification systems. The extent of local spread and the growth pattern at the invasive margin of the tumour, which are of known prognostic importance, were significantly related to some nuclear features. Discriminant analysis of the nuclear morphometric data alone was highly successful in predicting these tumour characteristics. The results suggest that routine application of this technique to tumour biopsies may be of value in patient management since it provides stage-related information which cannot be obtained by conventional histopathological assessment.

Adenocarcinoma↗
PubMed1989

Cephalometric and cineradiographic study of deviant resonance in hearing-impaired speakers.

To study physiological basis for deviant resonance in hearing-impaired speakers, cephalometric roentgenography and cineradiography were applied to analyze oral/pharyngeal relationships during vowels produced in isolation and within a sentence context. The films, synchronized with sound recording, were traced and measured for 10 normal hearing and 4 hearing-impaired women with deviant resonance. Vocal tract conformations and dimensions were defined by measures of the lips, tongue, mandible, velum, hyoid bone, epiglottis, and laryngeal sinus. Means, standard deviations, and analyses of variance were applied to facilitate descriptions and comparisons between the groups. The hearing-impaired speakers had near normal lip openings for /i/ and /u/ but more open positions for /a/. The tongue tended to retract for the front vowel and front for the back vowel /u/. For high vowels, most of the hearing-impaired speakers had an elevated hyoid, an unusually large vertical dimension between hyoid and laryngeal sinus, and a retracted tongue root, which was associated with a marked retraction or deflection of the epiglottis toward the pharyngeal wall. The cine analysis of the normal hearing speakers showed rather well defined and consistent shifts in tongue position for the front vowels produced in the sentence context. The hearing-impaired speakers with deviant resonance showed greater variation among speakers in tongue body position and a significant retrusion of the dorsum of the tongue at a site significantly lower than observed in hearing speakers. The consistent tongue root retraction during static as well as dynamic speech production is interpreted as support for Boone's hypothesized cause of pharyngeal resonance in speech of the hearing impaired.

Adult↗
PubMed1988

Campylobacter-like organisms and Candida in peptic ulcers and similar lesions of the upper gastrointestinal tract: a study of 247 cases.

Campylobacter-like organisms were detected by light microscopy in association with 57 of 102 (56%) of gastric ulcers, all the gastric erosions associated with gastritis, three of five (60%) of gastric erosions without gastritis, five of 13 (39%) of mild superficial gastritis and two of 36 (6%) of normal gastric mucosa. They were also seen in four of 20 (20%) of duodenal ulcers, but not in duodenal erosions with duodenitis or normal duodenal biopsy specimens. They were seen in association with 12 of 64 (19%) of cases of Barrett's oesophagus. Moniliasis was seen in nine of 78 (12%) of the gastric ulcers in which campylobacter-like organisms were found, and the incidence of moniliasis was three of 15 (20%) in association with duodenal ulcers when ulcer debris was present in biopsy material, and in association with six of 25 (24%) of cases of Barrett's oesophagus. These findings do not support the hypothesis that campylobacter-like organisms cause inflammatory and ulcerative lesions of the upper gastrointestinal tract.

Barrett Esophagus↗
PubMed1987

The morphogenesis of the human Paneth cell. An immunocytochemical ultrastructural study.

In human duodenal mucosa Paneth cells originate away from the base of crypts and migrate towards the base during maturation. The earliest cells in the Paneth cell lineage could be identified by labelling of lysozyme in the Golgi apparatus. Specific labelling for lysozyme was present in the rough endoplasmic reticulum, Golgi apparatus, condensing vacuoles, granules and many lysosomes of mature Paneth cells. The maturation of the Paneth cell is accompanied by an increase in the content of lysozyme in the secretory granules and with senescence lysozyme diffuses into the cytoplasm.

Cell Differentiation↗
PubMed1986

Gastric hemorrhage due to ruptured arteriovenous malformation (Dieulafoy's disease).

Dieulafoy's disease is one of the less common causes of significant hematemesis and/or melena. It occurs most frequently in middle-aged and elderly males, but both sexes and all ages may be affected. Histopathologically the lesion found is variable but includes the classical single large tortuous artery as well as thin-walled venous anomalies, and mixtures of these two. We present 4 cases of this condition.

Adult↗