Effects of hypoglycemia and prolonged fasting on insulin and glucagon gene expression. Studies with in situ hybridization.

In situ hybridization of proinsulin and proglucagon mRNA was performed in rat pancreas to assess prohormone gene expression during various glucopenic conditions. During a 4-d fast mean blood glucose declined by 48 mg/dl; proinsulin mRNA signal density remained normal while proglucagon mRNA signal density more than doubled. At the end of a continuous 12-d insulin infusion blood glucose averaged 53 +/- 12 mg/dl; proinsulin mRNA signal density declined to 30% of controls while proglucagon mRNA signal density more than doubled.

Molecular and cellular responses of islets during perturbations of glucose homeostasis determined by in situ hybridization histochemistry.

We have evaluated in situ hybridization histochemistry as a means of estimating simultaneously the level of prohormone mRNA and the dimensions of rat pancreatic islets. Localization of the 27-mer 32P-labeled oligonucleotide probes for rat proinsulin I, glucagon, and prosomatostatin I corresponded with localization of antibodies to the three hormones. In normal rats subjected to chronic hyperglycemic clamping, the density of the proinsulin mRNA signal increased 54%, islet size and number increased approximately 100%, while proglucagon mRNA signal was reduced 81%.

A 3D building blocks approach to analyzing and predicting structure of proteins.

A new approach is introduced for analyzing and ultimately predicting protein structures, defined at the level of C alpha coordinates. We analyze hexamers (oligopeptides of six amino acid residues) and show that their structure tends to concentrate in specific clusters rather than vary continuously. Thus, we can use a limited set of standard structural building blocks taken from these clusters as representatives of the repertoire of observed hexamers.

[The immunohistochemistry of pituitary adenomas].

A great deal of progress has been achieved in recent years in the field of immunohistochemistry of pituitary adenoma. Continued use of more new antisera and monoclonal antibodies against numerous hormones in the adenohypophysis have resulted in new approaches to classification of pituitary adenoma. However, new problems have been discovered, on the other hand, by large-scale studies in recent years.

Comparison of dot-blot and Northern blot hybridizations in the determination of genetic relatedness of United States bluetongue virus serotypes.

Dot-blot and Northern blot hybridization methods to determine the genetic relatedness of United States bluetongue virus serotypes 2, 10, 11, 13, and 17 were compared. Both plasmid and insert DNA probes from cloned BTV-17 dsRNA segments 2, 5, 6, and 8 were hybridized to dsRNA from the BTV serotypes and epizootic hemorrhagic disease virus (EHDV). Stringencies of hybridization were kept identical, and experiments differed only in the method in which dsRNA was applied to the membranes (dot-blot or Northern blot).

The cloning of full-length genome segments 2, 5, 6, and 8 of bluetongue virus (BTV) serotype 17 and studies of their genetic relatedness to United States BTV serotypes.

The double-stranded (ds) RNA genome segments 2, 5, 6, and 8, which encode the outer capsid proteins P2 and P5, and the two nonstructural proteins, NS1 and NS2, respectively, of bluetongue virus (BTV) serotype 17 have been cloned into pBR322. The length of the cloned genes indicates that the entire respective dsRNA genome has been cloned in each case. The four cloned genes were used as 32P-labeled probes to hybridize to PAGE-separated United States BTV serotypes 2, 10, 11, 13, and 17.

Comparison of a high-carbohydrate diet with a high-monounsaturated-fat diet in patients with non-insulin-dependent diabetes mellitus.

We compared a high-carbohydrate diet with a high-fat diet (specifically, a diet high in monounsaturated fatty acids) for effects on glycemic control and plasma lipoproteins in 10 patients with non-insulin-dependent diabetes mellitus (NIDDM) receiving insulin therapy. The patients were randomly assigned to receive first one diet and then the other, each for 28 days, in a metabolic ward. In the high-carbohydrate diet, 25 percent of the energy was in the form of fat and 60 percent in the form of carbohydrates (47 percent of the total energy was in the form of complex carbohydrates); the high-monounsaturated-fat diet was 50 percent fat (33 percent of the total energy in the form of monounsaturated fatty acids) and 35 percent carbohydrates.

Colony hybridizations using nylon membranes and RNA probes--an improved method for screening bacterial clones containing bluetongue virus genome.

Bluetongue virus (BTV) total genomic and isolated individual segment dsRNAs end-labeled with 32P were successfully used as probes in colony hybridization to detect clones of BTV genomic material. The RNA probes were highly specific for cloned BTV genomic material. DNA probes, however, gave false positive results.

Severe diabetes induced in subtotally depancreatized dogs by sustained hyperglycemia.

Chronic clamping of plasma glucose levels at greater than or equal to 250 mg/dl in four partially depancreatized but previously nondiabetic dogs was followed within 2 wk by persistent hyperglycemia and glycosuria of less than or equal to 500 g/day, ketonuria, and weight loss. Three of the four dogs required daily insulin injections to control these catabolic manifestations. There was no evidence of spontaneous improvement of the severe diabetic state during the 39-69 days of observation after discontinuation of intravenous glucose infusion.

Absence of glucopenic inhibition of the insulin response to arginine at the onset of diabetes in BB/W rats.

To determine if the inhibiting effect of glucopenia on arginine-stimulated insulin secretion is impaired at the onset of autoimmune diabetes, the insulin response to arginine was studied at 5.6 and 2.8 mmol/l glucose in perfused pancreata isolated from BB/W rats on the first day of diabetes and from age-matched diabetes-prone BB/W rats without diabetes.

Formate-nitrate respiration in Salmonella typhimurium: studies of two rha-linked fdn genes.

Localized mutagenesis was used to obtain rha-linked mutations in Salmonella typhimurium, resulting in defects in the nitrate reductase-linked formate dehydrogenase (FDHN). The fdn mutants obtained fell into two groups which differed in several respects. Group I isolates lacked FDHN activity under all conditions examined and exhibited wild-type levels of the hydrogenase-linked formate dehydrogenase (FDHH).

Morphologic and functional changes in sympathetic nerve relationships with pancreatic alpha-cells after destruction of beta-cells in rats.

Insulin-dependent diabetes mellitus (IDDM) in humans is accompanied by an attenuation of the response of glucagon to hypoglycemia. To identify an animal model of IDDM with alpha-cell unresponsiveness to glucopenia in which to pursue morphologic and in vitro functional investigation of the lesion, pancreases isolated from rats with IDDM induced by streptozocin (STZ) or occurring spontaneously in BB/W rats were perfused with buffer containing 150, 25, and 150 mg/dl of glucose. In both forms of IDDM the normal glucagon rise during glucopenia was markedly impaired, suggesting an abnormality comparable to that of human IDDM.

[Aneurysm surgery in relation to secondary intracranial findings].

In 116 patients operated on because of aneurysms we found 125 aneurysms, one convexity meningioma, and one A. V. supratentorial angioma.

[Surgery of aneurysms of the cerebral arteries--results and problems].

Surgery has been performed on 100 intracranial aneurysms during the past seven years. Of these, 96 involved the application of microsurgical techniques and could definitely be clipped. Lethality was 8%.

Relationship of glucagon suppression by insulin and somatostatin to the ambient glucose concentration.

The glucagon-suppressing activity of insulin and somatostatin were compared at high and low glucose concentrations. In normal dogs made hyperglucagonemic by phloridzin pretreatment, insulin and somatostatin suppressed glucagon at rates of 47 +/- 8 and 35 +/- 8%/h (NS), respectively, despite profound hypoglycemia. In severely hyperglycemic alloxan-diabetic dogs, insulin and somatostatin suppressed glucagon at rates of 48 +/- 13 and 54 +/- 6%/h, respectively, not different from the nondiabetic dogs.

DNAMAT: an efficient graphic matrix sequence homology algorithm and its application to structural analysis.

We present a fast algorithm to produce a graphic matrix representation of sequence homology. The algorithm is based on lexicographical ordering of fragments. It preserves most of the options of a simple naive algorithm with a significant increase in speed.

Inhibitory effects of beta-adrenergic agonists on gastric acid secretion in dogs.

We evaluated the effect of two beta-adrenergic agonists, isoproterenol (nonselective agonist) and terbutaline (selective beta 2-agonist), on gastric acid secretion stimulated by intravenous pentagastrin, bethanechol, or histamine in dogs with gastric fistulas. Intravenous infusion of isoproterenol or terbutaline inhibited pentagastrin-stimulated acid secretion to a significantly greater extent than they inhibited bethanechol- or histamine-stimulated acid secretion. For example, isoproterenol (12 micrograms X kg-1 X h-1) reduced mean pentagastrin-, bethanechol-, and histamine-stimulated acid output by 86, 63, and 14%, respectively.