PubMed Health⌕ Search

Biomedical subjects

D Perry

Publications and source records attributed to D Perry.

At least 37 records · Page 2Linked to original sources
PubMed1995

Coronary artery bypass grafting in an achondroplastic dwarf.

To our knowledge, coronary bypass for complications of coronary artery disease in achondroplasia has not previously been described. Achondroplasia, in and of itself, is not a contraindication to coronary bypass. Although the anatomic reserve of saphenous vein is less in achondroplastic dwarfs than in people of normal stature, that vessel and the internal mammary artery can be harvested in routine fashion. A 60-year-old woman with several risk factors for coronary artery disease underwent successful bypass surgery, which included the use of both a saphenous vein and the left internal mammary artery.

Achondroplasia↗
PubMed1994

Postoperative intramyocardial abscess caused by mucormycosis.

We report the case of an intramyocardial abscess caused by mucormycosis that arose after cardiac operation. Several causes of immunosuppression in a 71-year-old woman were exacerbated after she underwent coronary revascularization. Before she died of multiple organ system dysfunction, a variety of supraventricular and ventricular arrhythmias, as well as complete heart block, developed, but the cause was not clear until autopsy revealed a large septal myocardial abscess due to mucormycosis.

Abscess↗
PubMed1993

A brain-tumor model utilizing stereotactic implantation of a permanent cannula.

A tumor model involving stereotactically implanted culture-reared tumor cells is presented. Stainless steel cannulas were stereotactically and permanently implanted into the caudate nucleus of 30 rats. The animals were separated into two groups. In Group I, 15 animals received a 10-microliters injection containing 10(6) C6 glioblastoma cells (five rats), 10(6) Walker 256 breast carcinoma cells (five rats), or cell medium (five rats). The coordinates were A(+1.5), L(+3.0), and DV(-5.0). In Group II, the coordinates were changed to A(+1.0), L(+3.0), and DV(-5.0) and the same number of rats received a 1-microliter injection containing 10(5) cells of each tumor in an attempt to produce more focal tumors. Two weeks after implantation, brain sections were stained with cresyl violet and a subset was stained for glial fibrillary acid protein (GFAP). A computerized morphometric analysis system was used to quantify tumor size. In Group I, the mean C6 tumor areas (+/- standard error of the mean) at specific coordinates were (in sq mm): A(+4.7) 0.4 +/- 0.2; A(+3.7) 3.5 +/- 1.1; A(+2.7) 5.7 +/- 1.7; A(+1.7) 9.5 +/- 2.3; A(+0.7) 7.5 +/- 3.2; A(-0.3) 3.7 +/- 2.9; and A(-1.3) 0.3 +/- 0.3. A nearly identical tumor mass and extension into the brain was produced in rats injected with Walker 256 cells. Similar C6 tumor areas were indicated in adjacent sections stained with cresyl violet and GFAP. Tumor was found in the caudate nucleus in all 10 rats, but not in the nucleus accumbens, fornix, or hippocampus. In Group II animals, tumor magnitude and extension into the brain were greatly reduced. The 10(6) cells in the 10-microliters volume was the most reliable tumor load for obtaining uniform tumors in different animals. The similarity of tumor distribution across different animals was indicated by the low variance of tumor area at specific anteroposterior coordinates. Reproducible and well-circumscribed caudate nucleus tumors were produced using this stereotactic procedure.

Animals↗
PubMed1992

[Aortopulmonary fistula due to failed graft for aortic aneurysm].

Hemoptysis originating from an aortobronchial fistula is uncommon. This fistulous connection between the aorta and the lung usually results from a preexisting thoracic-aortic aneurysm, and is uniformly fatal when left untreated. However, with early diagnosis the survival rate exceeds 80%. The case of an aortobronchial fistula in a young alcoholic, 2 years after aortic aneurysmectomy, is presented. He was admitted with symptoms suggesting upper gastrointestinal bleeding, allegedly related to alcohol abuse. He died of a sudden, massive hemoptysis 5 days after admission. An aortobronchial fistula was found on autopsy. To diagnose aortobronchial fistula, a high index of suspicion is necessary. It should be considered in patients with hemoptysis after repair of a thoracic aneurysm.

Adult↗
PubMed1992

Oxygen utilisation by isopenicillin N synthase from Penicillium chrysogenum.

The enzyme isopenicillin N synthase (IPNS) converts delta-(L-alpha- aminoadipyl)-L-cysteinyl-D-valine (ACV) to isopenicillin N; an equimolar amount of oxygen is used in this oxidative ring closure reaction. Oxygen uptake rates of the reaction catalysed by partially purified IPNS from Penicillium chrysogenum SC 6140 and P2 were measured using an oxygen electrode. In contrast to published properties of Cephalosporium acremonium IPNS, the enzyme from P. chrysogenum was not stimulated by the addition of glutathione and showed reduced stimulation by Fe2+. The analysis of oxygen uptake rates showed the reaction to be first order with respect to oxygen concentration and the Km for ACV to be 0.4 mmol dm-3. The implications of these results for cell-free reactions using this enzyme and penicillin fermentations are discussed.

Biotechnology↗
PubMed1992

Attenuation of exercise induced asthma by local hyperthermia.

BACKGROUND: Prior treatment with local hyperthermia has been shown to prevent mast cell degranulation and leucocyte histamine release, and to reduce mortality and cellular infiltrates in a model of acute lung injury. Local hyperthermia is effective in reducing the symptoms of the common cold and perennial and seasonal allergic rhinitis, nasal patency also being improved in rhinitis. It is possible that these effects are mediated by common anti-inflammatory mechanisms, and that this treatment may be effective in the treatment of asthma. The effect of prior local hyperthermia on the response to exercise challenge and histamine bronchoprovocation was therefore examined. METHODS: In a randomised, double blind, placebo controlled, crossover study, 10 asthmatic subjects with exercise induced asthma used machines delivering 40 1/minute of fully humidified air at either 42 degrees C (active treatment) or 31 degrees C (placebo treatment) for 30 minutes' tidal breathing. For each pretreatment, at two week intervals they underwent exercise challenges starting one and 24 hours after starting the inhalations. After a further two weeks the protocol was repeated with histamine substituted for the exercise challenges. RESULTS: The mean (SE) maximum percentage fall in forced expiratory volume in one second (FEV1) was significantly lower one hour after treatment with air at 42 degrees C (30.8% (3.1%)) than after treatment with air at 31 degrees C (22.3% (2.9%)). There was no significant effect on exercise challenge at 24 hours, or on histamine challenge at either time point, though there were nonsignificant trends towards protection with exercise at 24 hours and with histamine at one hour. CONCLUSION: In asthmatic subjects the response to exercise challenge is significantly attenuated one hour after treatment with local hyperthermia. This treatment warrants further investigation in the treatment of clinical asthma and other inflammatory disorders.

Adolescent↗
PubMed1991

Isolation of delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine from culture broths by covalent chromatography.

An efficient procedure for the isolation of reduced delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV) from culture supernatants of beta-lactam antibiotic-producing microorganisms is described. The method utilises covalent chromatography to isolate thiols from culture broths that have been deproteinised and undergone borohydride reduction. 2-Pyridyl disulphide activated thiopropyl Sepharose was employed batchwise to isolate the thiols present in such broths from cultures of the known ACV excreter Cephalosporium acremonium N2 and the penicillin producer Penicillium chrysogenum P2. ACV was separated from these mixtures of thiols by gel permeation chromatography. Reversed-phase HPLC analysis showed the ACV to be of a high purity unless isolated from a highly complex culture medium.

Acremonium↗
PubMed1991

Neuronal specific protein NP185 is enriched in nerve endings: binding characteristics for clathrin light chains, synaptic vesicles, and synaptosomal plasma membrane.

The neuronal specific protein NP185, found associated with brain clathrin-coated vesicles, formed a complex with unphosphorylated, but not with phosphorylated, clathrin light chains. The NP185-clathrin light chain complex was associated with casein kinase II activity, which, in the presence of polylysine, phosphorylated clathrin light chain b but not the NP185. The dissociation of this complex with 50% ethylene glycol pH 11.5 suggests that NP185 binds to hydrophobic domains of clathrin light chains. When NP185 molecules were retained by monoclonal antibody-linked Sepharose beads, they bound synaptic vesicles, decoated vesicles and synaptosomal plasma membrane. Immunohistochemistry on mouse cerebellar tissue sections using 8G8, a monoclonal antibody raised against NP185, showed neuronal specific labeling closely following synaptic distribution. In immunoblots, NP185 shares similar epitopes to those detected in another assembly polypeptide, AP-180, an indication that both proteins are identical. It appears that NP185 plays a specific role in nerve ending functions through its ability to induce clathrin to polymerize into cages, its interaction with synaptic vesicles, with the plasma membrane and with clathrin coat components.

Adaptor Proteins, Vesicular Transport↗
PubMed1991

Anaerobic work and power output during cycle ergometer exercise: effects of bicarbonate loading.

Eight trained male cyclists who competed regularly in track races, were studied under control, alkalotic (NaHCO3) and placebo (CaCO3) conditions in a laboratory setting to study the effect of orally induced metabolic alkalosis on 60 s anaerobic work and power output on a bicycle ergometer. Basal, pre- and post-exercise blood samples in the three conditions were analysed for pH, pCO2, pO2, bicarbonate, base excess and lactate. All blood gas measurements were within normal limits at basal levels. There were significant differences in the amount of work produced, and in the maximal power output produced by the cyclists in the experimental condition when compared to the control and placebo conditions (P less than 0.01). The post-exercise pH decreased in all three conditions (P less than 0.05) and post-exercise pCO2 increased significantly in the alkalosis trial (P less than 0.01). In the alkalotic condition, the pre-exercise base excess and HCO3- levels were both higher (P less than 0.05) than the basal levels, suggesting that the bicarbonate ingestion had a significant increase in the buffering ability of the blood. Post-exercise lactate levels were significantly higher (P less than 0.05) after the alkalotic trial when compared to the other two conditions, immediately post-exercise and for the next 3 min. Post-exercise lactate levels were higher than basal or pre-exercise levels (P less than 0.001). This was true immediately post-exercise and for the next 5 min. The results of this study suggest that NaHCO3 is an effective ergogenic aid when used for typically anaerobic exercise as used in this experiment. We feel that this ergogenic property is probably due to the accelerated efflux of H+ ions from the muscle tissue due to increased extracellular bicarbonate buffering.

Adult↗
PubMed1991

Inhibition of mitochondrial cholesterol side-chain cleavage by structural analogs of cholesterol sulfate.

Cholesterol sulfate inhibits cholesterol side-chain cleavage in adrenal mitochondria. In this study, analogs of cholesterol sulfate were evaluated for their ability to inhibit steroidogenesis. Structural requirements for inhibitory activity included a planar A-B ring junction, an intact side chain, and a 3 beta-ester group containing a single negative charge. This structural specificity argues against cholesterol sulfate acting solely as a membrane perturbing agent or a detergent, and also differs in some features from the specificity for binding to cytochrome P-450scc.

Adrenal Glands↗
PubMed1991

Is rheumatoid arthritis in Indians associated with HLA antigens sharing a DR beta 1 epitope?

HLA class II antigens were identified in a group of 44 patients with rheumatoid arthritis (RA) originating largely from the north or northeast of the Indian subcontinent and resident now in east London. Compared with 67 locally typed east London Asian controls, the prevalence of three HLA-DR antigens was raised in the patients: DR1 18.2% v 6.0% chi 2 = 3.99, DR4 20.5% v 11.9% chi 2 = 1.48, and DRw10 27.3% v 8.9% chi 2 = 6.56. These differences were also found when the patients with RA were compared with a larger control group of 110 northern Indians: DR1 18.2% v 7.2% chi 2 = 4.02, DR4 20.5% v 7.2% chi 2 = 5.56, and DRw10 27.3% v 8.1% chi 2 = 9.7. Twenty five (57%) of the patients expressed at least one of these antigens. All patients were also characterised for HLA-Dw types by mixed lymphocyte culture typing. The prevalence of the HLA-DR4 associated Dw types in the patients was: Dw4 2.3%, Dw10 0%, Dw14 11.4%, and Dw15 6.8%. The DR beta 1 chains of DR1 and DRw10 together with the Dw types of DR4 other than Dw10 share amino acid residues in a region of the third hypervariable region considered to be critical in antigen presentation. It is concluded that RA in Indians is associated with these HLA antigens, and data from this study support the hypothesis of a cross reactive epitope common to HLA specificities associated with RA.

Arthritis, Rheumatoid↗