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Biomedical subjects

R Whitehead

Publications and source records attributed to R Whitehead.

At least 73 records · Page 4Linked to original sources
PubMed1980

Why do surgical packs cause peritoneal adhesions?

Our experiments in the Porton rat have shown that the foreign debris from surgical sponges left in the peritoneal cavity after use is not the cause of peritoneal adhesions. Instead, the abrasive effect of introducing the sponge produces mesothelial trauma. This is the stimulus for an inflammatory response, followed by adherence of adjacent involved peritoneal surfaces. Adhesions formation did not occur between the abraded peritoneal surfaces of mobile intraabdominal viscera, which suggests that intestinal motility in the early postoperative period is important in the prevention of adhesions.

Animals↗
PubMed1980

Calcitonin and 1,25-dihydroxyvitamin D3 receptors in human breast cancer cell lines.

Five human breast cancer cell lines (MCF 7, T 47D, BT 20, MDA 157, and MDA 231) and a human breast epithelial cell line (HBL 100) have been found to contain specific high-affinity receptors for 1,25-dihydroxyvitamin D3, Kd values ranged from 0.6 to 2.0 X 10(-11) M and receptor concentration from 31 to 150 fmol/mg cytosol protein. Two of the breast cancer lines (MCF 7 and T 47D) contain specific high-affinity receptors for calcitonin and a calcitonin-responsive adenylate cyclase, which have been characterized with the aid of salmon, eel, and human calcitonins and in several substituted analogues of human calcitonin. The 1,25-dihydroxyvitamin D3 receptor may reflect a normal property of the breast cell. Breast cancer cell lines provide a useful source of 1,25-dihydroxyvitamin D3 receptors. Their coexistence with a calcitonin receptor and biological response in some breast cancers offers the opportunity to investigate new aspects of breast cancer endocrinology.

Adenylyl Cyclases↗
PubMed1980

Effect of nicotine on the morphology of the rat gastric mucosa.

The effect of oral nicotine dosage on the morphology of the rat gastric mucosa was studied. Cell populations, neck cell mucus volume fraction, and mucosal area and depth were measured, and differences in mean values for each group were tested for statistical significance. It was found that the equivalent of approximately 10 times the normal daily intake of nicotine achieved by human smoking is related to a significant decrease in total mucus neck cell population, neck cell mucus volume fraction and mucosal depth and to an increase in mucosal surface area. The nicotine doses caused no significant changes in the parietal or chief cell populations, body weight, or water consumption.

Animals↗
PubMed1979

Do surgical packs cause peritoneal adhesions?

In spite of the growing variety of materials being used in the manufacture of intraabdominal packs (sponges), no data have been published on their adhesion-producing properties. We have shown that the Porton rat will reliably produce peritoneal adhesions in response to ischaemia and glove powder. In a randomized control trial using this rat model, we tested the adhesogenic potential of two commercially available surgical packs. Both brands of pack were shown to cause a significant incidence of postoperative peritoneal adhesions (P is less than 0.005), irrespective of whether the packs were used wet or dry. It is recommended that the adhesogenic potential of all products for use within the peritoneal cavity be established in an animal model prior to marketing.

Animals↗
PubMed1979

Measuring intraepithelial lymphocytes, surface area, and volume of lamina propria in the jejunal mucosa of coeliac patients.

An accurate morphometric method is described for quantifying the intraepithelial lymphocytes (IEL), the area of the epithelium, and the volume of the lamina propria in jejunal mucosa of coeliac patients. All measurements are related to a unit-length of muscularis mucosa which is unaltered by the disease process. The results show a significant decrease in the epithelial surface area and an increase in the volume of the lamina propria in coeliac jejunal mucosa compared with normal levels, even after treatment. The number of IEL is the same as normal before or after treatment. Other workers have shown an apparent increase in IEL in untreated disease which returns to normal levels after therapy. This discordance is explained and the importance of accurate quantitative methodology is stressed.

Celiac Disease↗
PubMed1979

The Paneth cell.

Explore the source record for details and available documents.

Adult↗
PubMed1979

Ultrastructural analysis of plasma cells in coeliac patients.

By accurate morphometry the length of the rough endoplasmic reticulum (RER) was estimated in electron micrographs of a population of jejunal plasma cells in biopsies obtained from normal volunteers, untreated coeliac disease patients, and coeliac disease patients treated for one year on a gluten free diet. Increase in length or hypertrophy of the endoplasmic reticulum is an indication of increased protein synthesis of the cell (Ghadially, 1977). An increase compared with normal length was demonstrated in the mean length of the plasma cell rough endoplasmic reticulum in plasma cells obtained from both groups of coeliac patients. This estimate of increased protein production--in this case immunoglobulin--indicates an increase in the immunological activity of plasma cells even after treatment and suggests not only a reaction to dietary gluten but probably to other antigens also.

Anthropometry↗
PubMed1979

Gastin cells and fasting gastrin levels in duodenal ulcer patients: a quantitative study based on multiple biopsy specimens.

The number of gastrin-producing cells in biopsy specimens from the gastric and duodenal mucosae in 19 duodenal ulcer patients was quantitated using a morphometric method. The level of immunoreactive gastrin in a sample of fasting serum obtained at the time of the biopsy was measured by radioimmunoassay. The results show no significant difference when compared with those from a group of normal control volunteers. Moreover, there was no correlation between the numbers of gastrin-producing cells and the fasting serum gastrin level in either controls or duodenal ulcer patients.

Adolescent↗
PubMed1979

Hepatotoxicity and halothane metabolism in an animal model with application for human toxicity.

Centrilobular necrosis and a ten-fold elevation in serum alanine amino-transferase (ALT) consistently followed 2 hours of 1% halothane anaesthesia in an animal model. Conditional factors were the presence of enzyme induction and moderate hypoxia (14% oxygen), indicating an association between reductive metabolism and hepatotoxicity. Under these conditions there was at least a four-fold increase in reductive metabolites detected in the exhaled air. In clinical studies, reductive metabolites were also detected in the exhaled air of all patients examined, even after halothane anaesthesia with 100% oxygen. The amounts of reductive metabolites were comparable in man and the model, following equivalent halothane doses. It appears that a model with a similar route and rate of halothane biotransformation to man has been identified. The lesion of halothane hepatotoxicity in this model appears to be similar to that reported in man - centrilobular hepatic necrosis.

Alanine Transaminase↗
PubMed1979

Mucins and carcinoid tumours.

Mucin was demonstrated in 11 of 16 carcinoid tumours of usual histological appearances. The mucin was characterized histochemically and shown to be similar to that which is produced in the gastrointestinal as well as the respiratory tract. This relative ubiquity of mucin in carinoid tumours has not hitherto been appreciated and more obviously "mixed" tumours have been regarded as rareties. The importance of these findings with respect to the neural crest theory of origin of enterochromaffin cells is discussed.

Carcinoid Tumor↗
PubMed1979

Morphometric electron and light microscope analysis of lymphoid cells in coeliac disease.

Lymphocytes in jejunal biopsies from normal subjects and from untreated, treated, and gluten-challenged coeliac patients were examined by accurate morphometric methods. There was no significant difference between lymphocytes from different sources and those in the jejunum. Transforming lymphocytes were ultrastructurally quite different from non-transforming lymphocytes. The appearance of transforming lymphocytes in the lamina propria in different groups of coeliac patients is in accordance with the increase in the number of plasma cells. In treated patients the results indicate a rapid humoral response to gluten challenge.

Celiac Disease↗
PubMed1978

Enflurane nephrotoxicity and pre-existing renal dysfunction.

This study provides the first morphological evidence of significant structural damage following high doses of enflurane alone and confirms previous findings of transient renal functional abnormalities following high dosage enflurane. The study also indicates that enflurane may have a greater potential for renal toxicity in the presence of renal impairment. Treatment of Fischer 344 rats with a nephrotoxic dose of gentamicin prior to six hours of enflurane (GE) anaesthesia at 1 MAC resulted in increased serum concentration of the enflurance metabolite inorganic fluoride (GE, 43.9 +/- 1.5; E, 34.5 +/- 1.8 mu mol/L), increased urine flow rate and a greater degree of structural damage in renal proximal convoluted tubule cells than was observed with either gentamicin (G) or enflurane (E) alone. Treatment with gentamicin prior to enflurane also resulted in reduced urinary osmolality compared to enflurane or gentamicin alone (GE, 742 +/- 57; E, 1709 +/- 66; G, 985 +/- 32 m0sm/kg).

Anesthesia, Inhalation↗
PubMed1976

Disseminated intravascular thrombosis as the cause of ischaemic enterocolitis.

Disseminated intravascular thrombosis was diagnosed in a woman aged 63 years. At autopsy the typical appearances of ischaemic enterocolitis were found, together with thrombi in other organs. This case illustrates the previously postulated connection between intravascular thrombosis and ischaemic enterocolitis.

Disseminated Intravascular Coagulation↗