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Biomedical subjects

G E Bauer

Publications and source records attributed to G E Bauer.

At least 55 records · Page 3Linked to original sources
PubMed1977

Detection and follow-up of moderate and severe hypertensive subjects in the Australia community.

A national screening project has detected 989 subjects aged 30 to 69 years with untreated moderate or severe hypertension. The 1-2% incidence of this condition indicates a total of about 100,000 people in the Australian community potentially requiring therapy. The sample showed that half the subjects were previously unaware of a blood pressure problem. Those so detected showed a very high rate (90-7%) of acceptance of advice to see their own doctor. The local doctors confirmed the elevated pressure level in nearly two-thirds of the patients referred, and initiated treatment in a similar proportion.

Adult↗
PubMed1977

Isolation of osteoclasts by velocity sedimentation at unit gravity.

A method is presented for separating osteoclasts from the heterogeneous population of bone and marrow cells. Cell suspensions were prepared from femora of young rabbits by mechanical dispersion. The starting cell suspension typically contained only 1.0% +/- 0.5 osteoclasts. Following an initial 45 min of unit gravity sedimentation in a lucite chamber osteoclasts were primarily distributed in fractions 2-5. A second 45-min sedimentation of these pooled fractions yielded cell suspensions containing greater than 30% osteoclasts (as much as a 50-fold increase over starting percentages). Linear scan analysis, however, revealed that osteoclasts accounted for 73.14% +/- 0.58 of the cell colume. Subsequent in vitro experiments demonstrated linear incorporation of 3H-leucine into TCA precipitable protein for cells comprising the osteoclast fraction. Concomitant radioautographs revealed radioactive label in isolated osteoclasts.

Animals↗
PubMed1977

Studies on proinsulin and proglucagon biosynthesis and conversion at the subcellular level. I. Fractionation procedure and characterization of the subcellular fractions.

Anglerfish islets were homogenized in 0.25 M sucrose and separated into seven separate subcellular fractions by differential and discontinuous density gradient centrifugation. The objective was to isolate microsomes and secretory granules in a highly purified state. The fractions were characterized by electron microscopy and chemical analyses. Each fraction was assayed for its content of protein, RNA, DNA, immunoreactive insulin (IRI), and immunoreactive glucagon (IRG). Ultrastructural examination showed that two of the seven subcellular fractions contain primarily mitochondria, and that two others consist almost exclusively of secretory granules. A fifth fraction contains rough and smooth microsomal vesicles. The remaining two fractions are the cell supernate and the nuclei and cell debris. The content of DNA and RNA in all fractions is consistent with the observed ultrastructure. More than 82 percent of the total cellular IRI and 89(percent) of the total cellular IRG are found in the fractions of secretory granules. The combined fractions of secretory granules and microsomes consistently yield >93 percent of the total IRG. These results indicate that the fractionation procedure employed yields fractions of microsomes and secretory granules that contain nearly all the immunoassayable insulin and glucagons found in whole islet tissue. These fractions are thus considered suitable for study of proinsulin and proglucagon biosynthesis and their metabolic conversion at the subcellular level.

Animals↗
PubMed1977

Studies on proinsulin and problucagon biosynthesis and conversion at the subcellular level. II. Distribution of radioactive peptide hormones and hormone precursors in subcellular fractions after pulse and pulse-chase incubation of islet tissue.

Anglerfish proinsulin and insulin were selectively labeled with [(14)C]isoleucine, while proglucagon, conversion intermediate(s), and glucagon were selectively labeled with[(3)H]tryptophan. After various periods of continuous or pulse-chase incubation, islet tissue was subjected to subcellular fractionation. Fraction extracts were analyzed by gel filtration for their content of precursor, conversion intermediate(s), and product peptides. Of the seven subcellular fractions prepared after each incubation, only the microsome and secretory granule fractions yielded significant amounts of labeled insulin-related and glucagon-related peptides. After short-pulse incubations, levels of both [(14)C]proinsulin and [(3)H]proglucagon (mol wt approximately 12,000) were highest in the microsome fraction. This fraction is therefore identified as the site of synthesis. With increasing duration of continuous incubation or during chase incubation in the absence of isotopes, proinsulin, proglucagon, and conversion intermediate(s) are transported to secretory granules. Conversion of proinsulin to insulin and proglucagon to a approximately 4,900 mol wt conversion intermediate and 3,500 mol wt glucagon occurs in the secretory granules. Converting activity also was observed in the microsome fraction. The recovery of most of the incorporated radioactivity in microsome and secretory granule fractions indicates that the newly synthesized islet peptides are relegated to a membrane-bound state soon after synthesis at the RER is completed. This finding supports the concept of intracisternal sequestration and intragranular maintenance of peptides synthesized for export from the cell of origin.

Animals↗
PubMed1976

Personality deviancy and prison incarceration.

This investigation was designed to study personality differences among prison inmates that could be attributed to the number of felony offenses and the length of incarceration. MMPI profiles of 93 inmates of a medium security prison were obtained and analyzed. Special attention was directed to the five MMPI variables K, D, PD, SC, and MA. These five variables taken collectively successfully differentiated first offenders from repeaters and short-term from long-term inmates. The results support the hypothesis that increased incarceration has a harmful effect upon personality.

Antisocial Personality Disorder↗
PubMed1976

Immunohistochemical localization of somatostatin, insulin and glucagon in the principal islets of the anglerfish (Lophius americanus) and the channel catfish (Ictalurus punctata) (1) (2).

Somatostatin, insulin and glucagon were localized in the principal islets of the anglerfish (Lophius americanus) and the channel catfish (Ictalurus punctata) by means of the unlabeled antibody-peroxidase-antiperoxidase immunocytochemical method. Both species showed a similar ratio of positive cells 9:6:4 (insulin:somatostatin:glucagon), but the interrelations of the three cell types differed between species. The large number of somatostatin-positive cells may be indicative of an important role for this hormone in teleost physiology. The principal islets appear to be a good source of tissue for further work on somatostatin.

Animals↗
PubMed1976

Hypertension and headache.

The frequent association between headache and hypertension has been recognized since the introduction of the sphygmomanometer. A cause and effect relationship proposed by early writers and widely accepted in the medical and lay community has been proposed, questioned and re-examined. The purpose of this review is to scan the literature on the subject, to present some factual data obtained from a 20 year follow-up study carried out at the Cardio-Vascular Clinic, Sydney Hospital and to summarize some personal views currently held on the relationship of hypertension and headache.

Adult↗
PubMed1976

Mortality patterns in treated hypertension: results from Sydney Hospital.

A group of hypertensive patients, diastolic blood pressure 110 mm Hg or more and under the age of 60 years at the time of presentation, has been followed at the Cardiovascular Clinic, Sydney Hospital since 1955. Changes in the causes of death have been observed during the twenty-year period of observation. Patients with severe and treatment-resistant hypertension are likely to die of cerebro-vascular accidents, patients presenting with advanced retinopathy with papilloedema and established renal failure die predominantly of uraemia. The fate of patients with moderate degrees of blood pressure elevation, without papilloedema and with normal renal function, seems to be to succumb to the complications of ischaemic heart disease.

Adult↗
PubMed1976

Regulation of proinsulin synthesis in isolated rat islets.

(1) A system is described for studying the short-term effects of agents on proinsulin synthesis in vitro, as measured by the incorporation of [3H]leucine into isolated proinsulin. (2) Of the agents tested, glucose has the most marked, and apparently earliest, effect on proinsulin synthesis. (3) The adenyl cyclase system participates in the regulation of proinsulin synthesis since exogenous cyclic AMP, glucagon, and caffeine are stimulatory. When cyclic AMP is added to the medium in the presence of glucose, it is the most potent agent acting on the adenyl cyclase-phosphodiesterase system. (4) The addition of NADPH to isolated rat islets inhibits proinsulin and Bulk Protein synthesis in vitro.

Animals↗
PubMed1976

Studies on rats with islet beta cell tumors induced by nicotinamide and streptozotocin.

Islet beta cell adenomata were induced in rats by combined treatment with nicotinamide and streptozotocin. Three weeks after treatment marked alterations in glucose tolerance were noted in animals which later exhibited large beta cell tumors. Eight months after treatment, the rats known to have beta cell tumors on the basis of marked hypoglycemia and later confirmed by autopsy showed variable response to a glucose load. Some tumor-bearing rats showed fast response to glucose load, their blood sugar levels were elevated moderately and returned to normal or below normal levels rapidly; these animals are described as having "fast-acting tumors". Rats with "slow-acting tumors" responded sluggishly to a glucose load; their blood glucose pattern was similar to that of subdiabetic animals. Animals with beta cell tumors exhibited elevated serum insulin levels 30 min after glucose administration. Insulin biosynthesis by beta cell adenomata was demonstrated by in vitro incorporation of [14C]leucine into proinsulin and insulin. In the small number of tumor samples studied, a stimulatory effect of glucose on insulin biosynthesis was observed.

Adenoma↗
PubMed1975

Glucagon biosynthesis in human pancreatic islets: preliminary evidence for a biosynthetic intermediate.

Viable pancreatic islets were isolated from the pancreas of humans using modifications of the collagenase digestion and Ficoll gradient techniques. Gel filtration of tissue extracts following islet incubation in the presence of 3H- tryptophan indicated that radioactivity becomes incorporated into at least two islet proteins. The larger of the two (LGI) has the approximate molecular size of proinsuiln and the smaller coelutes with glucagon as determined by column standardization. Radioimmunoassay of the gel filtration eluate for glucagon revealed that both molecules have glucagon immunoreactivity. Gel filtration in the presence of 8M urea did not alter the elution pattern of the LGI molecule. Polyacrylamide gel electrophoresis was performed on these glucagon immunoreactive molecules. The 3H radioactivity and the glucagon immunoreactivity of the smaller molecule were found to co-migrate electrophoretically with crystalline porcine glucagon and monodesamidoglucagon. With electrophoresis at high pH the electrophoretic mobility of the LGI molecule proved to be lower than that of glucagon. Partial tryptic degradation of the human LGI molecule yields 3H-tryptophan labeled products having charge and immunologic characteristics indistinguishable from porcine glucagon and monodesamidoglucagon. Although further investigation is indicatend may thus serve as a precursor or an intermediate in human glucagon biosynthesis.

Antigens↗
PubMed1975

Evidence of sequential metabolic cleavage of proglucagon to glucagon in glucagon biosynthesis.

Following a 30 min preincubation in medium containing no isotopes, anglerfish islet tissue was incubated in the presence of [3H]tryptophan and [14C]isoleucine for 20 min. A portion of the tissue was removed for immediate extraction. The remainder was washed thoroughly with unlabeled medium and post-incubated in medium containing an excess of unlabeled tryptophan and isoleucine for varying periods of time. The distribution of radioactive proteins in alcoholic tissue extracts was analyzed by gel filtration and polyacrylamide gel electrophoresis. The distribution of immunoreactive glucagon was determined by radioimmunoassay. Following the 20 min pulse incubation, only proinsulin was labeled with [14C]isoleucine. Two glucagon immunoreactive molecules, one larger than proinsulin (mol wt near 11,400) and the other slightly smaller than proinsulin (mol wt near 9,000), were the primary proteins labeled with [3H]tryptophan following the 20 min. pulse. During chase incubations of increasing duration, 3H-radioactivity appeared in a glucagon immunoreactive molecule with the approximate molecular size of glucagon and increased with chase time while radioactivity in the 11,400 mol wt tryptophan-labeled molecule decreased. With increasing chase time, the 3H-radioactivity attributable to the 9,000 mol wt tryptophan-labeled molecule initially increased and subsequently decreased which is consistent with the pattern that would be expected for a conversion intermediate. The presence of glucagon immunoreactivity in [3H]tryptophan-labeled molecules having molecular weights near that of proinsulin was established by radioimmunoassay of alternate gel slices following electrophoresis of labeled proteins recovered from the proinsulin containing portions of gel filtration eluates. That [14C]isoleucine became incorporated into insulin and [3H]tryptophan became incorporated into glucagon was established by determination of the distribution of radioactivity in polyacrylamide gels following electrophoresis of labeled proteins recovered from the insulin and glucagon containing portions of gel filtration eluates. These results provide preliminary evidence for sequential metabolic cleavage of proglucagon in glucagon biosynthesis.

Animals↗