Search PubMed⌕ Search

Biomedical subjects

M D Williams

Publications and source records attributed to M D Williams.

At least 127 records · Page 7Linked to original sources
PubMed1986

Transplantation of pancreatic islets in dogs.

Dispersed pancreatic islet tissue, prepared by collagenase digestion without separation of exocrine and endocrine components, was transplanted into the splenic pulp of 12 dogs made diabetic by total pancreatectomy. Four dogs (group 1) were given autotransplants, and all became euglycemic 4.5 +/- 1.5 days (mean +/- SE) after the transplantation was done. Three of these dogs remained euglycemic until splenectomized 60 days after transplantation was done. Four dogs (group 2) given allogeneic transplants from histocompatible littermates within the same group were administered cyclosporine (40 mg/kg of body weight/day; starting 2 days before transplantation was done until dogs were splenectomized), and 3 of these dogs became euglycemic 8.0 +/- 2.0 days after the transplant was done. Two of the 3 dogs that became euglycemic remained so until splenectomized 60 days after transplantation was done, and the 3rd was euglycemic until 31 days after transplantation. Four dogs (group 3) given allogeneic islet transplants from nonrelated histocompatible donors within the same group were given cyclosporine (40 mg/kg/day; as described for group 2), and none became euglycemic.

Animals↗
PubMed1986

Effects of prednisolone on glucose tolerance and insulin secretion in the dog.

Effects of prednisolone on glucose tolerance and insulin secretion were evaluated in healthy dogs. Dogs were given 1 mg of prednisolone/kg of body weight/day (n = 5) or 2 mg of prednisolone/kg/day (n = 6) orally for 3 weeks. Intravenous glucose tolerance tests (600 mg/kg) were administered before and after treatment to evaluate plasma glucose in fasting dogs, glucose fractional clearance rate, serum insulin in fasting dogs, insulin peak response, total insulin secretion, and insulinogenic index. A significant difference (P less than 0.05) in plasma glucose in fasting dogs was observed for the 2 mg/kg dose, although values were still within the reference range. There was no significant effect on glucose fractional clearance rate (glucose tolerance) or insulin secretion. Seemingly, peripheral insulin resistance resulting in hyperinsulinemia or decreased glucose tolerance could not be identified in association with 1 or 2 mg of prednisolone/kg/day for 3 weeks in healthy dogs.

Animals↗
PubMed1985

Epidermal inclusion cysts in a cow.

A 6-year-old Hereford-cross cow had multiple 2-cm diameter, well-circumscribed, firm, nonulcerated cutaneous nodules along the ventral midline. Biopsy of several nodules revealed epidermal inclusion cysts. Such cysts may be of economic importance because they affect hide quality in beef and dairy cattle.

Animals↗
PubMed1985

Lymphocyte subset ratios and factor VIII usage in haemophilia.

Type and quantity of replacement treatment, together with haematological and immunological parameters were determined in 37 boys with severe haemophilia A and 41 children with other bleeding disorders. The quantity of factor VIII concentrate given to boys with severe haemophilia A (mean U/year) showed a significant inverse correlation with total white cell counts, lymphocyte counts, platelet counts, and the ratio of monoclonal antibody defined T lymphocyte subsets, T4 and T8 (T4:T8). Of the boys with severe haemophilia A, 49% had inversed T4:T8 ratios and 24% had thrombocytopenia. Treatment with high dose factor VIII concentrate (more than 25 000 U/year) was associated with low platelet counts, low lymphocyte counts, low T4:T8 ratios, and hypergammaglobulinaemia. In addition, six patients with severe haemophilia A and factor VIII inhibitors had inversed T4:T8 ratios. Patients treated exclusively with cryoprecipitate or prothrombin complex concentrates had normal T4:T8 ratios and platelet counts. The severity of the haematological and immunological abnormalities observed seems to be associated with high usage of factor VIII concentrates. Similar abnormalities have been described in patients with the acquired immune deficiency syndrome (AIDS). Prospective study of haemophiliacs is required to assess long term sequelae of factor concentrate usage, including the possible development of AIDS.

Child↗
PubMed1985

Unusually high incidence of tuberculosis among boys with haemophilia during an outbreak of the disease in hospital.

Of 30 children with bleeding disorders exposed to an index tuberculosis case, six developed primary pulmonary tuberculosis and two others became positive skin reactors. There was a significant correlation between the amount of replacement treatment received and the development of evidence of tuberculous infection. Only two of those who developed evidence of tuberculosis had antibodies to the human T cell lymphotropic virus. These two boys showed much later Mantoux positive conversion than the six others.

Child↗
PubMed1985

Some nonsteroidal antiinflammatory drugs inhibit the generation of superoxide anions by activated polymorphs by blocking ligand-receptor interactions.

Representatives of the major classes of nonsteroidal antiinflammatory drugs (NSAID) were assessed for their effects on superoxide anion (O2-.) production by human polymorphonuclear leukocytes stimulated with phorbol myristate acetate or N-formyl methionyl-leucyl phenylalanine (fMLP). Three levels of effects were studied: (1) overall inhibition of O2-. production, (2) the inhibition of interaction between fMLP and specific receptors at the cell surface, and (3) intermediate proenzyme and enzyme effects. Some, but not all drugs inhibited O2-. production. In general, drugs that inhibited O2-. production inhibited fMLP-receptor interactions in a consistent dose dependent fashion, showing noncompetitive kinetics. Drugs that failed to inhibit O2-. production showed weak and variable effects on receptor binding and on the intermediate enzymes. Clinical observations suggest that inflammation in diseases such as gout respond differently to NSAID than diseases such as rheumatoid arthritis; studies of drug effects may help to clarify the differences in pathogenesis of these inflammatory diseases.

Anions↗
PubMed1984

Clinical and laboratory findings of carcinoma of the pancreas and periampullary structures.

This is a retrospective review of 233 patients who had surgical exploration for proven or suspected malignant lesions of the exocrine pancreas and periampullary structures. There were 24 patients with carcinoma of the ampulla or duodenum, 12 with carcinoma of the bile duct, and 197 with lesions of the pancreas. Among the latter group, 128 patients had carcinoma diagnosed at initial operation (31 by duodenopancreatectomy, 33 by liver, and 64 by other biopsies), and 69 patients had suspected carcinoma of the pancreas without histological proof. History of jaundice, pruritus, nausea/vomiting, total weight loss, duration of pain, and values of blood urea nitrogen, bilirubin, alkaline phosphatase, and albumin were significantly different among the various groups. Patients who had resection of carcinoma of the duodenum or ampulla had the best 5-year survival rate (39 +/- 12%). Among patients with resectable or nonresectable carcinoma of the pancreas, some of the symptoms and laboratory tests studied had prognostic significance.

Actuarial Analysis↗
PubMed1984

Production and characterization of antibody against deoxyverrucarol.

Immunization of rabbits with deoxyverrucarol (DOVE) conjugated to bovine serum albumin resulted in antibodies bound with either tritiated DOVE or diacetoxyscirpenol (DAS), but not with T-2 toxin. The affinity of antibodies with DOVE was found to be much higher than with DAS. When [3H] DOVE was used as a marking ligand in the competitive radioimmunoassay, the concentrations causing 50% inhibition of binding radioactivities by unlabeled DOVE, verrucarol, verrucarin A, and 4-monoacetoxyscirpenol were found to be 0.32, 1,070, 9,500, and 10,000 ng per assay, respectively. T-2 toxin, 15-monoacetoxyscirpenol, and deoxynivalenol gave less than 20% inhibition at 10 micrograms per assay. However, when [3H] DAS was used as the marking ligand, the concentrations causing 50% inhibition by DOVE, DAS, and verrucarol were found to be in the 50 to 60 ng per assay range. The antibodies are thus highly specific to DOVE rather than a common trichothecene backbone. The possible use of this antiserum for assay of macrocyclic trichothecenes is discussed.

Animals↗
PubMed1984

A reevaluation of placental grading and its clinical significance.

Pregnancies complicated by preeclampsia or intrauterine growth retardation have an earlier and faster placental maturation than normal. This is demonstrated in a study of 1,096 obstetrical examinations of 473 non-diabetic mothers. It is recommended that a pregnancy demonstrating grade I maturational changes prior to 27 weeks, grade II changes prior to 32 weeks, or especially grade III changes prior to 34 weeks be followed clinically and ultrasonically for possible complications.

Female↗
PubMed1983

Spontaneous chemiluminescence of human breath. Spectrum, lifetime, temporal distribution, and correlation with peroxide.

Human breath spontaneously emits photons at a rate of approximately 7,000/liter-s. The emission has a peak in the red part of the spectrum and an ultraviolet contribution. The emission count rate correlates with peroxide concentration in a saturating manner under normal breathing conditions. When trapped in a balloon, the breath luminescence count rate has a half-decay time of approximately 20 min and exhibits more than one mode of decay. The photomultiplier pulses generated by breath luminescence arrive in bursts. The chemiluminescence process appears by these criteria to include chain reactions, long-lived emitters, or both.

Breath Tests↗
PubMed1976

de Broglie waves in amoeboid motility.

The de Broglie wave equation has been applied to the study of amoeboid motility. This leads to precise predictions of wavelengths displayed by the cellular membrane during motility. Motile amoeba are compared to non-biological systems showing de Broglie wave behavior, and three simple experiments are suggested.

Amoeba↗
PubMedDate not supplied

Laparoscopic cholecystectomy produces less postoperative restriction of pulmonary function than open cholecystectomy.

This study was undertaken to determine whether laparoscopy produces less postoperative decrease in pulmonary function than does open operation. Ten elective laparoscopic cholecystectomy patients (LC group) were compared to 10 elective open cholecystectomy patients (OC group). Spirometry was performed preoperatively and then postoperatively as soon as each patient was awake and cooperative. The two groups were similar with respect to age, gender, and preexisting medical illness. No patient had underlying cardiopulmonary disease. Postoperatively, forced vital capacity, forced expiratory volume in 1 s, and maximum forced expiratory flow decreased to 56%, 55%, and 43% of preoperative values in the OC group and to 72%, 76%, and 81% of preoperative values in the LC group. These decreases were significantly greater in the OC group as compared to the LC group, P values < or = 0.05. Cholecystectomy had a significant restrictive effect on immediate postoperative pulmonary function. Laparoscopic cholecystectomy produced significantly less restriction.

Adult↗
PubMedDate not supplied

Laparoscopic insufflation of the abdomen depresses cardiopulmonary function.

Recently we have used the laparoscope to remove the gallbladder in critically ill patients in order to spare them the operative trauma of laparotomy. However, increased intraperitoneal pressure may have deleterious cardiopulmonary effects. This was investigated in a dog model. Insufflation of the abdomen with carbon dioxide decreased the mean cardiac output to less than 80% of baseline (P < 0.004). This was aggravated by the reverse Trendelenburg position and partially alleviated by the Trendelenburg position. Mean arterial PCO2 and mean peak airway pressure significantly rose. These effects are of doubtful clinical significance in the majority of patients. However, to extend the benefits of laparoscopy to patients with decreased cardiopulmonary reserve, hemodynamic and carbon dioxide monitoring should be used because measures to improve venous return, augment cardiac output, and counteract the increase in PCO2 and peak airway pressure may be required.

Abdomen↗
PubMedDate not supplied

Arterial embolisation of a facial haemangioma.

Non-invasive investigations in the diagnosis of highly vascular lesions are without doubt a sound principle. A case is presented however, in which the clinical diagnosis of a haemangioma was confirmed by ultrasound and magnetic resonance imaging (MRI) but required further investigation by angiography to facilitate treatment. Embolisation is a well established technique available in most large radiology departments, but may not be well known by general dental practitioners.

Adult↗