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Biomedical subjects

J Simmons

Publications and source records attributed to J Simmons.

At least 73 records · Page 4Linked to original sources
PubMed1988

Brain acetylcholinesterase activity is markedly reduced in dominantly-inherited olivopontocerebellar atrophy.

The activity was measured of the acetylcholine catabolising enzyme acetylcholinesterase (AChE) in brain after necropsy of seven patients from one established pedigree with dominantly-inherited olivopontocerebellar atrophy (OPCA), a cerebellar ataxia disorder in which neuropathological changes are assumed to be primarily restricted to cerebellum, lower brain stem and spinal cord. Mean AChE activity was significantly reduced in cerebral (-51% to 65%) and cerebellar (-47%) cortex with a less severe change (-37%) in the hippocampus. The magnitude of the enzyme reduction in cerebral cortex was equal to or greater than that reported in brain of demented Alzheimer's and Parkinson's disease patients having loss of AChE-containing nucleus basalis cholinergic neurons. It is concluded that the data provide additional biochemical evidence suggesting a cerebral cortical cholinergic denervation in OPCA.

Acetylcholinesterase↗
PubMed1987

Renal-metabolic consequences of antihypertensive therapy with diltiazem versus hydrochlorothiazide.

Twenty-seven patients with mild to moderate essential hypertension were randomized to receive therapy with either hydrochlorothiazide or diltiazem. After a placebo run-in period of 2 weeks, patients received increasing doses of either drug for 14 weeks. Those in whom hypertension was effectively controlled continued for 26 weeks of total treatment. Those not controlled, i.e. blood pressure greater than 140/90 mm Hg or less than 10 mm Hg reduction of pressure, were unblinded and crossed over to therapy with both drugs. Eleven of 14 patients (79%) were effectively treated with diltiazem alone, and 8 of 13 patients (62%) were effectively treated with hydrochlorothiazide alone. Supine blood pressures fell from 152 +/- 5/97 +/- 1 to 142 +/- 4/87 +/- 3 mm Hg in the 11 patients treated with diltiazem, from 152 +/- 2/99 +/- 1 to 134 +/- 3/88 +/- 2 mm Hg in the 8 patients treated with hydrochlorothiazide, and from 151 +/- 4/104 +/- 3 to 140 +/- 5/92 +/- 1 mm Hg in the 8 patients who received both drugs (p less than 0.01 for each group). Diltiazem patients had significant increases in alkaline phosphatase and urinary magnesium. Hydrochlorothiazide patients had increases in serum uric acid, serum globulin, CO2 content, and plasma renin activity. Serum potassium, serum chloride, urinary osmolality, and urinary calcium decreased after treatment with hydrochlorothiazide. Patients receiving both drugs had increases in serum glucose, serum BUN, serum uric acid, serum globulin, and CO2 content. These patients had decreased serum chloride and urinary calcium. Diltiazem monotherapy was comparable to hydrochlorothiazide in efficacy of lowering blood pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Antihypertensive Agents↗
PubMed1986

House calls by New Hampshire family practitioners.

We surveyed current activities and attitudes regarding house calls among New Hampshire family physicians. Fifty of a random sample of 72 eligible participants returned a brief questionnaire. They reported on 134 house calls they made during the two weeks prior to the survey. Eighty-four percent of participants offered house calls, averaging 2.68 house calls per physician over the two week study period. Most house calls were to the elderly or homebound for management purposes. Physicians thought house calls were important, but often an inefficient use of their time. Financial and time constraints were the most commonly cited limiting factors. The decision to make a house call is based on clinical judgment regarding the individual case and broader issues involving the physician's whole practice. Unless external constraints change, house calls will continue to be an uncommon event.

Adult↗
PubMed1985

Construction of the mycoplasma evolutionary tree from 5S rRNA sequence data.

The 5S rRNA sequences of eubacteria and mycoplasmas have been analyzed and a phylogenetic tree constructed. We determined the sequences of 5S rRNA from Clostridium innocuum, Acholeplasma laidlawii, Acholeplasma modicum, Anaeroplasma bactoclasticum, Anaeroplasma abactoclasticum, Ureaplasma urealyticum, Mycoplasma mycoides mycoides, Mycoplasma pneumoniae, and Mycoplasma gallisepticum. Analysis of these and published sequences shows that mycoplasmas form a coherent phylogenetic group that, with C. innocuum, arose as a branch of the low G+C Gram-positive tree, near the lactobacilli and streptococci. The initial event in mycoplasma phylogeny was formation of the Acholeplasma branch; hence, loss of cell wall probably occurred at the time of genome reduction to approximately to 1000 MDa. A subsequent branch produced the Spiroplasma. This branch appears to have been the origin of sterol-requiring mycoplasmas. During development of the Spiroplasma branch there were several independent genome reductions, each to approximately 500 MDa, resulting in Mycoplasma and Ureaplasma species. Mycoplasmas, particularly species with the smallest genomes, have high mutation rates, suggesting that they are in a state of rapid evolution.

Base Sequence↗
PubMed1984

Enhancement of Chlamydia trachomatis infectious progeny by cultivation of HeLa 229 cells treated with DEAE-dextran and cycloheximide.

The effects of DEAE-dextran and cycloheximide on the infection of HeLa 229 cells with Chlamydia trachomatis serotype G were studied in terms of the number of cells infected and the yield of infectious progeny per infected cell. Pretreatment of the host cells with DEAE-dextran resulted in an increase in the number of infected cels but had no significant effect on the yield of infectious progeny per infected cell (burst size). In contrast, the addition of cycloheximide to the medium of infected cells had no significant effect on the number of infected cells but greatly enhanced the burst size. The burst size was calculated to be close to 500. The enhanced burst size was also observed in cells treated with DEAE-dextran and cycloheximide. In addition, there was an increase in the number of cells infected and an augmentation of the infectious progeny yield. Under the conditions of combined treatment, the yield of C. trachomatis serotype G cultivated in HeLa 229 cells was found to be approximately threefold higher than the yield of the organisms cultivated in McCoy cells. The results suggest that HeLa 229 cells treated with DEAE-dextran and cycloheximide offer a most suitable system for the high-yield cultivation of C. trachomatis organisms and possibly also for the diagnosis of infection with these organisms.

Bacteriological Techniques↗
PubMed1984

Glutamic dehydrogenase activity in rat heart: demonstration of two forms of enzyme activity.

Glutamic dehydrogenase (GDH) activity in rat heart was found to be 2.1 U/g of heart (wet wt). The mitochondrial glutamic dehydrogenase activity accounted for only 18% of the total. This percentage of the total activity in heart mitochondria was not altered by nagarse treatment, acetone extraction, sonication in Triton X-100, and extraction with buffer containing a protease inhibitor. The remainder of the activity was present in the cytosol. Cytosolic GDH activity differed from mitochondrial GDH activity by its pH curve, stability to heat, Arrhenius plot, and the effect of different nucleotides. Acetone extraction of the mitochondria resulted in GDH that was stable to heat and had a shallow temperature activation curve resembling cytosolic GDH. Acetone extraction of cytosolic GDH inactivated it. The cytosolic activity was purified 288-fold and the mitochondrial activity 100-fold. Purified cytosolic and mitochondrial GDH enzymes had different monomeric molecular weights on sucrose density gradient centrifugation. Gel filtration of cytosolic and mitochondrial GDH also showed different monomeric molecular weights. We conclude that rat heart GDH exists in two forms with different physical and kinetic characteristics. The majority of GDH activity in rat heart is cytosolic. The mitochondrial enzyme has a lipid-soluble component that can be removed with acetone without destroying its activity.

Animals↗
PubMed1984

Medical self-care education for elders: a controlled trial to evaluate impact.

We conducted a trial to evaluate the impact of medical self-care education on 330 elders whose average age was 71. The test group participated in a 13-session educational intervention with training in clinical medicine, life-style, and use of health services. The comparison group received a two-hour lecture-demonstration. Both groups were assessed pre-intervention, post-intervention, and one year after entry. The results indicate medical self-care instruction: produces substantial improvements, that were sustained for one year, in health knowledge, skills performance, and skills confidence; stimulates many attempts to improve life-style; and generates improvements in life quality. The program had little influence on utilization of medical care or health status.

Aged↗
PubMed1982

The nucleotide sequence of the 5S rRNA from Spiroplasma species BC3 and Mycoplasma mycoides sp. capri PG3.

Using in vitro labelling techniques, the complete nucleotide sequence of the 5S ribosomal RNAs isolated from the honeybee pathogen, Spiroplasma species BC3 and Mycoplasma mycoides sp. capri PG3, have been determined. The latter shows only 3 differences from the reported sequence of M. capricolum 5S rRNA, indicating that these two species are very closely related. The Spiroplasma sequence is also 107 nucleotides long and a comparative analysis of the sequence confirms that this Spiroplasma species is closely related to the Mycoplasma species and that they and the Gram-positive eubacteria have descended from a common ancestor and in the process the cell wall-less organisms have lost a large percentage of their genome.

Base Sequence↗