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Biomedical subjects

B Burke

Publications and source records attributed to B Burke.

At least 109 records · Page 6Linked to original sources
PubMed1987

Preservation of thrombomodulin antigen on vascular and extravascular surfaces.

The protein C anticoagulant system is mediated by thrombin and is highly accelerated by thrombomodulin. We studied the distribution of thrombomodulin antigen (TM Ag) in the rabbit using an affinity-purified antibody raised in a goat against rabbit thrombomodulin. The preservation of TM Ag was highly dependent on immediate fixation of the surface on which it is located. TM Ag was found on the endothelium of the entire vasculature, whereas it was absent from all connective tissue, smooth and striated muscle, secretory epithelia, cartilage, bone, neural tissue, and all parenchyma examined. A new finding was the presence of TM Ag on nonvascular surfaces of body cavities (the mesothelia of pleura, pericardium, and peritoneum, the synovial membrane, and the arachnoid enveloping the central nervous system). By use of a functional assay, TM activity was recovered in buffered saline/detergent solution which was either injected into the intraperitoneal cavity of rabbits in vivo or incubated with the surface of the arachnoid in vitro. These findings extend the importance of anticoagulant mechanisms to the systems of slowly circulating fluids, in which they might be required for maintenance of the flow, and to mesothelial cavities, in which they could be necessary for preventing adherence between the surfaces, in conditions associated with pathological exudation.

Animals↗
PubMed1987

Isolation and characterization of an undifferentiated human colon carcinoma cell line (MIP-101).

An undifferentiated human colon carcinoma cell line was established from tumor tissue obtained from metastasis to the liver of colonic adenocarcinoma in a patient with fulminant Dukes D colorectal carcinoma. Histological analysis of the tumor biopsy from the liver confirmed the hospital pathology report of poorly differentiated colonic adenocarcinoma. Explants of this tumor tissue xenografted into a nude mouse were used to establish an epithelioid-like cell culture line, MIP-101. The cell line formed tumors in nude mice that histologically appeared undifferentiated and did not stain for carcinoembryonic antigen (CEA). No CEA was present either by radioimmunoassay (RIA) of the culture supernatant or by immunoperoxidase staining of the tumors or monolayers. MIP-101 appears to be one of the most undifferentiated human colon carcinoma cells lines available. It should prove useful in the search for markers of undifferentiated colonic cancer and in studies of colonic cancer differentiation.

Adenocarcinoma↗
PubMed1987

[Different localization of thrombomodulin].

Thrombomodulin (TM) is the endothelial cofactor of the anticoagulant protein C system. The distribution of TM in the organism was studied in the rabbit using a goat anti TM, affinity-purified antibody and a peroxidase-labelled antigoat immunoglobulin. TM antigen was found on the endothelial surface of all blood vessels: capillaries, arteries and veins. The reaction was specific: connective tissue, smooth and striated muscle bone, cartilage, nerve tissue, secretary epithelia and all parenchyma studied were not strained. Moreover TM antigen was present on the surface of serosa: peritoneum, pericardium and pleura as well as on synovial membranes and on arachnoid, all along the central nervous system. It was absent from pia and dura mater. The antigen was found only after formalin fixation on the vessels and body cavities surface on which it lies. This observation shows that the antigen is easily detached from these surfaces and suggest a possible mobility of this endothelial molecule for which it lies. This observation shows that the antigen is easily detached from these surfaces and suggest a possible mobility of this endothelial molecule for which production and function sites might differ.

Animals↗
PubMed1987

A comparison of the pharmacokinetics of human protamine sodium insulin with human isophane insulin following subcutaneous injection in normal subjects.

The pharmacokinetics of human protamine sodium insulin 0.6 mg% were compared with those of human isophane zinc insulin using the glucose clamp technique. The insulin preparations were administered subcutaneously at a dose of 0.5 U/kg in 7 normal subjects; a placebo injection served as control. Plasma insulin and C-peptide concentrations were then measured over 24 hours. After correction of the results to allow for endogenous insulin secretion the two insulin preparations gave similar values throughout the study except that protamine sodium insulin achieved an earlier peak in plasma insulin concentration (90 minutes) compared to isophane (120 minutes). When measured by an index of the dextrose infusion rate required to maintain euglycaemia the two insulin preparations gave similar values for the first 16 hours, maximum values being obtained during the fourth hour after administration. Using this index isophane zinc insulin gave higher values during the 17th, 19th and 21st hours following administration suggesting it may have a slightly more prolonged action than protamine sodium insulin.

Adult↗
PubMed1987

Insulin infusion and serum potassium in normal subjects.

Two groups of healthy males of normal body mass index underwent hyperinsulinaemic glucose clamp procedures during studies of insulin resistance. Insulin was infused for 2 consecutive 100 minute periods at 40 and 400 mU.m-2.min-1, plasma glucose being maintained by 20% dextrose infusion via a Biostator. One group received 20 mmol/l potassium chloride in the dextrose infusate, calculated to replace the extracellular potassium deficit due to the action of insulin on potassium flux. Despite this, serum potassium fell equally in both groups in response to each level of insulin infusion.

Adult↗
PubMed1987

Splenic hemangioma with thrombocytopenia in a newborn.

The case report of a newborn infant with a splenic hemangioendothelioma with the life-threatening complications of thrombocytopenia, anemia, and disseminated intravascular coagulation is presented together with a review of the literature. Removal of the tumor via splenectomy, despite the known risk of subsequent overwhelming sepsis due to encapsulated organisms in the young child, is the treatment of choice for splenic hemangiomas complicated by thrombocytopenia. The use of enhanced CT with delayed filling is a diagnostic tool in the workup of suspected hemangiomatous lesions.

Anemia, Neonatal↗
PubMed1986

A cell free system to study reassembly of the nuclear envelope at the end of mitosis.

We described a cell free system involving total homogenates of metaphase CHO cells, which yields telophase-like assembly of nuclear envelopes around mitotic chromosomes. During formation of the nuclear envelope in vitro, the three major lamina polypeptides (lamins A, B, and C) assemble around chromosomes and become dephosphorylated, similar to their behavior in vivo during telophase. Nuclear lamina and envelope assembly apparently do not require free ATP and are strongly inhibited by gamma-S-ATP, supporting the notion that these processes are regulated by protein dephosphorylation. Immunological depletion of disassembled lamins from the initial assembly system results in strong inhibition of subsequent nuclear envelope assembly, directly demonstrating that the lamins are involved in this process.

Adenosine Triphosphate↗
PubMed1986

Use of barbiturate therapy in severe perinatal asphyxia: a randomized controlled trial.

The possible cerebral sparing effect of thiopental was evaluated in 32 severely asphyxiated neonates randomly assigned to either a thiopental treatment or control group. All infants had neurologic manifestations of asphyxia and required assisted ventilation. Thiopental was begun at a mean age of 2.3 hours and was given as a constant infusion that delivered 30 mg/kg over 2 hours. Treatment was continued at a lower dose for 24 hours. Seizure activity occurred in 76% of infants given thiopental and 73% of control infants at a mean age of 1.5 and 2.5 hours, respectively. Although initial arterial blood pressure was similar in both groups, hypotension occurred in 88% of treated and 60% of control infants. The amount of blood pressure support required was significantly greater (P less than 0.005) in the thiopental treatment group. Three infants died in the control group, and five in the treatment group. Developmental assessment was performed at a minimum of 12 months of age in 22 infants. There were no significant differences in neurologic, cognitive, or motor outcome between groups. Deteriorating performance over time was a consistent trend in both groups. These findings indicate that treatment of severe perinatal asphyxia with thiopental does not appear to have a cerebral sparing effect and may be associated with significant arterial hypotension.

Apgar Score↗
PubMed1986

Evaluation of a therapeutic strategy for the treatment of acne vulgaris with conventional therapy.

Four hundred and twenty patients with moderate to severe acne vulgaris were treated with oral erythromycin and topical benzoyl peroxide to determine the optimum dose regimes. Our results show that the response was significantly less in patients with a greater severity of acne, with truncal acne and in those with a higher sebum excretion rate. There was a significantly better clinical result in patients given Ig erythromycin daily than in those given 0.5 g daily (plus topical therapy in both groups). The relapse rate on stopping antibiotics is also significantly less in patients given I g daily and this dosage did not produce any increase in side effects. We suggest that any patient requiring oral antibiotics should initially be given I g daily of erythromycin (or tetracycline) for up to six months, plus topical therapy.

Acne Vulgaris↗
PubMed1986

Maternal phenylketonuria-chronology of the detrimental effects on embryogenesis and fetal development: pathological report, survey, clinical application.

Maternal phenylketonuria (PKU) is likely to have detrimental effects on embryogenesis and fetal development. Manifestations in the offspring include spontaneous abortion, various congenital malformations, intrauterine growth retardation, and microcephaly. The time at which the metabolic abnormalities induce pathologic embryogenesis can be documented by knowing the time of the development of specifically damaged organ systems. This review reveals that, while the most recognized congenital malformations occur in the heart, the most common abnormality is growth inhibition occurring throughout pregnancy. The organ system most commonly affected by this growth inhibition is the brain, resulting in a high incidence of micrencephaly. It appears that maternal phenylketonuria interferes with appropriate fetal growth and that this effect occurs during the entire course of pregnancy and has no tissue specificity. This information can be both informative to pathologists and useful to clinicians.

Embryonic and Fetal Development↗
PubMed1985

Acne: double blind clinical and laboratory trial of tetracycline, oestrogen-cyproterone acetate, and combined treatment.

Since the recent introduction of a drug regimen containing 2 mg of the antiandrogen cyproterone acetate and 50 micrograms ethinyl-oestradiol (Diane; oestrogen-cyproterone acetate) several uncontrolled reports have extolled the benefits of this drug. Double blind studies, however, are lacking. Sixty two patients with moderate or moderately severe acne were therefore included in a double blind trial of treatment for six months comparing tetracycline alone, oestrogen-cyproterone acetate alone, and a combination of these agents. Sebum excretion rates and bacterial counts were measured before, during, and after treatment, at the same time as a clinical assessment was made. At six months the acne (as assessed by overall grade) had improved by 68% in the antibiotic treated group and by 74% in the oestrogen-cyproterone treated group. The group given a combination of both agents improved by 82%, which was significantly better (p less than 0.025) than the improvement in the tetracycline treated patients. No significant difference was found between the groups given oestrogen-cyproterone alone and the combined treatment. The sebum excretion rate was suppressed by 25% in the patients in both groups receiving oestrogen-cyproterone but not in the group given antibiotics alone. Oestrogen-cyproterone acetate is as effective as antibiotics in treating acne in women, and adding antibiotics offers no advantage over using oestrogen-cyproterone on its own, although in this study the combination was more effective than tetracycline alone at six months.

Acne Vulgaris↗
PubMed1985

Ultrastructural evidence of dimethylformamide-induced differentiation of cultured human colon carcinoma cells. Increased expression of desmosomes.

N,N-dimethylformamide (DMF) induces differentiation of human colon carcinoma (DLD-1) cells in culture and reduces their tumorigenicity in nude mice. The current investigation analyzed DLD-1 (clone D) cells for ultrastructural evidence of differentiation. Examination of treated and untreated confluent monolayers by transmission electron microscopy revealed an occasional intracytoplasmic lumen indicative of adenocarcinoma. DMF-treated cells showed no signs of a toxic reaction. Cytoplasmic organelles were essentially unchanged except for an increase in tonofilaments and associated desmosomes. The number of desmosomes per unit length of contiguous cell border increased almost sixfold in treated monolayers. No other type of cell junction was seen. The increased frequency of desmosomes in DMF-treated cultures is significant because of the direct correlation known to exist between the number of desmosomes and degree of differentiation of some human carcinomas. Desmosomes serve as foci of cell adhesion and are reduced in number in some invasive tumors. Whether the supernumerary desmosomes in DMF-treated cells contribute to the reduction in malignant behavior of these cells in vivo remains to be determined.

Acetylation↗
PubMed1984

Inhibition of N-linked oligosaccharide trimming does not interfere with surface expression of certain integral membrane proteins.

The effects of 1-deoxynojirimycin (dNM) and 1-deoxymannojirimycin (dMM), inhibitors of oligosaccharide trimming glucosidase I and mannosidase I, respectively, on the biosynthesis of vesicular stomatitis virus G protein, influenza virus hemagglutinin, and human class I histocompatibility antigens were investigated. Although the oligosaccharides of these membrane glycoproteins were greatly altered, neither dNM nor dMM interferred with their surface expression, as determined by a variety of assays, including accessibility to proteases and antibodies; neither did these drugs inhibit production of infectious virus particles.

1-Deoxynojirimycin↗