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Biomedical subjects

D J Buckley

Publications and source records attributed to D J Buckley.

At least 19 recordsLinked to original sources
PubMed1992

Polytetrafluoroethylene in above-knee arterial bypass surgery for critical ischemia.

Seventy-one consecutive above-knee polytetrafluoroethylene (PTFE) femoropopliteal arterial bypasses performed between 1981 and 1989 for critical ischemia were followed prospectively to determine graft patency and limb salvage. Cumulative graft patency and limb salvage rates were calculated by life table analysis. Graft patency was 80%, 68%, 55%, 39%, and 39%, and limb salvage 97%, 87%, 84%, 77%, and 77% at 1, 2, 3, 4, and 5 years, respectively. Twenty-nine grafts have occluded with re-emergence of critical ischemia in 14, treated by 5 amputations and 9 reconstructions using autogenous saphenous vein (ASV) in 6 and PTFE in 3. These favorable results are not as good in terms of primary patency as those reported with ASV, but good limb salvage, good early patency, ease of use, and preservation of the saphenous vein for use later have encouraged us toward primary use of PTFE in selected patients. This experience strongly questions the wisdom of an "all autogenous" policy for reconstruction at this level.

Amputation, Surgical↗
PubMed1991

Problems associated with interferences in the analysis of serum for polychlorinated biphenyls.

During a recent survey to determine serum concentrations of polychlorinated biphenyls (PCBs) among people living around New Bedford, MA, U.S.A., an unidentified contaminant precluded the quantification of some early eluting Webb and McCall peaks. Loss of data is estimated to have reduced reported serum levels by 12%. Efforts to identify the contaminant by gas chromatography with an electron-capture detector, a Hall electrolytic condutivity detector, and mass spectrometer were not successful. Researchers ascertained, however, that the contaminant is not a PCB, it does not contain halogens, but it may contain phthalates. Vacutainer tubes and closures for serum storage bottles are suspected sources of contamination.

Chromatography, Gas↗
PubMed1991

Mediastinoscopy as a predictor of resectability in patients with bronchogenic carcinoma.

Eighty consecutive mediastinoscopies, performed for assessment of patients with bronchogenic carcinoma, were reviewed with regard to accuracy and complications. Thirty patients had mediastinal lymph node metastases: 26 were considered inoperable and thus saved non-therapeutic thoracotomy, 4 were considered operable of whom 3 had a curative resection, and one was inoperable at thoracotomy. Of 50 patients with negative mediastinal nodes 43 had thoracotomy; 42 were resectable and one was unresectable. Seven did not have thoracotomy because of other contraindications. In total of 47 patients undergoing thoracotomy on the basis of mediastinoscopy, 45 were resectable, giving mediastinoscopy a positive predictive value for resectability of 95.7%. There was no mortality and two superficial wound infections occurred giving a morbidity of 2.5%. Mediastinoscopy is a safe, reliable and accurate predictor or resectability in patients with bronchogenic carcinoma and continues to have a major role in the management of these patients.

Aged↗
PubMed1991

Prolactin-stimulated ornithine decarboxylase induction in rat hepatocytes: coupling to diacylglycerol generation and protein kinase C.

The trophic effects of prolactin (PRL) in rat liver have been linked to activation of protein kinase C (PKC). Since alterations in PKC activity imply its activation by 1,2-diacylglycerol (DAG), we tested whether PRL treatment stimulated DAG generation coupled to induction of a growth response in primary hepatocytes. Addition of PRL to hepatocyte cultures significantly increased [3H]-glycerol incorporation into DAG within 5 minutes which was followed by a loss of cytosolic PKC activity by 10 minutes. Prolactin also significantly enhanced radiolabel incorporation into triacylglycerol and phospholipids within 10 minutes and induced ODC activity at 6 hours. Therefore, prolactin-stimulated alterations in PKC activity are preceded by enhanced DAG generation. Moreover, these events appear to be coupled to PRL-stimulated entry of hepatocytes into cell cycle.

Animals↗
PubMed1990

Protein kinase C inhibitors block insulin and PMA-stimulated hexose transport in isolated rat adipocytes and BC3H-1 myocytes.

Effects of protein kinase C (PKC) inhibitors and "down-regulation" on insulin and PMA-stimulated 2-deoxyglucose transport were determined in isolated rat adipocytes or BC3H-1 myocytes. In both model systems, H-7, sangivamycin, and staurosporine, inhibitors of the catalytic domain of PKC, each effectively blocked insulin and PMA-stimulated hexose uptake at similar concentrations. In the myocytes, staurosporine completely blocked the insulin effect retained post-chronic phorbol myristate acetate (PMA)-induced "down-regulation." These findings indicate (1) that chronic pretreatment with PMA may not lead to a complete loss of PKC activity in the myocyte, and (2) that PKC is involved in insulin-stimulated hexose transport in both isolated rat adipocytes and BC3H-1 myocytes.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1990

Oral complications in type 1B glycogen storage disease.

A case of type 1b glycogen storage disease (GSD) in which neutropenia and neutrophil dysfunction were prominent features is described. Oral complications included rapidly progressive periodontal disease and recurrent mucosal ulceration.

Adult↗
PubMed1990

Calcium antagonists and the "stunned" myocardium.

Hearts which are made ischemic for relatively short periods of time, and then re-perfused, exhibit a temporary decline in tension-generating activity but are not irreversibly injured". Experiments were undertaken to find out whether such "stunned" hearts develop a perfusion defect, and whether chemically heterogeneous Ca(2+)-antagonists provide protection, when used prophylatically. "Stunning" was produced by repetitive 10 minute episodes of ischemia, followed by 15 minutes of reperfusion. The experimental model was the Langendorff-perfused rat heart, and the perfusion buffer was Krebs-Henseleit solution at 37 degrees C. To detect perfusion defects, fuchsin dye was added to the buffer. No evidence of a perfusion defect was obtained. Nevertheless, 10(-8)M nifedipine. 10(-8)M verapamil, 10(-8)M felodipine, and 10(-7)M diltiazem all conferred protection, as gauged by recovery of function after three successive 10 minute episodes of ischemia.

Animals↗
PubMed1989

Influence of oxidised dietary oil and antioxidant supplementation on membrane-bound lipid stability in broiler meat.

1. The effects of oxidised oil, dietary alpha-tocopherol and BHA/BHT-supplementation on the fatty acid composition of mitochondrial, microsomal and soluble protein fractions of broiler muscles, and on their lability to metmyoglobin/hydrogen peroxide-catalysed peroxidation were investigated. 2. Oxidised oil in the broiler diets induced rapid oxidation of the membrane-bound lipids and decreased their stability towards metmyoglobin-hydrogen peroxide-catalysed peroxidation. 3. Supplementation of the broiler diets with alpha-tocopherol increased the alpha-tocopherol concentrations in the microsomal and soluble protein fractions of the dark meat as well as the soluble protein fraction of the white meat. This, in turn, stabilised the membrane-bound lipids against metmyoglobin/hydrogen peroxide-initiated peroxidative changes.

Animals↗
PubMed1989

Effects of oxidised dietary oil and antioxidant supplementation on broiler growth and meat stability.

1. Broilers were fed on diets containing oxidised sunflower oil, sunflower oil and sunflower oil supplemented with alpha-tocopherol, butylated hydroxyanisole (BHA) or butylated hydroxytoluene (BHT). 2. Oxidised oil caused a significant reduction in broiler body and carcase weights, whereas alpha-tocopherol and BHA/BHT supplementation improved growth. 3. Meat samples from these broilers were stored at 4 degrees C and -20 degrees C and their oxidative stability evaluated. Feeding oxidised oil to broilers resulted in meat that underwent rapid oxidative changes during refrigerated and frozen storage. 4. On the other hand, dietary alpha-tocopherol and BHA/BHT supplementation increased alpha-tocopherol and BHA/BHT concentrations in meat and significantly (P less than 0.05) improved the oxidative stability of meat during refrigerated and frozen storage.

Animals↗
PubMed1988

Contribution of wood smoke to in vivo formation of N-nitrosothiazolidine-4-carboxylic acid: initial studies.

The effect of administering liquid smoke or smoked food products to rats on in vivo formation of N-nitrosamino acids was investigated. Rats treated by gavage with either cysteine, formaldehyde or nitrite excreted urine containing no detectable levels of N-nitrosothiazolidine-4-carboxylic acid (NTCA). All three precursor compounds were required for NTCA formation. Two liquid smokes, when administered to rats in combination with cysteine and nitrite also produced measurable quantities of NTCA. Ascorbate inhibited in vivo formation of NTCA by approximately 90% when given to rats simultaneously with cysteine, formaldehyde, and nitrite. alpha-Tocopherol was much less effective than ascorbate in blocking NTCA formation. When smoked bacon, smoked Swiss cheese, and chicken barbecued with a sauce containing smoke flavouring were fed to rats along with nitrate, NTCA was again detected in the urine.

Acetaldehyde↗
PubMed1988

Dissociation of hypoxia-induced calcium gain and rise in resting tension in isolated rat hearts.

When isolated hearts are perfused with substrate-free hypoxic buffer for prolonged periods of time, resting tension and tissue Ca increase. These two events may be interrelated. Isolated rat hearts were used to establish whether the hypoxia-induced increase in tissue Ca can be dissociated from the rise in resting tension. Tension generation was inhibited at the start of hypoxic perfusion by adding 2,3-butanedione monoxime (BDM, 30 mM). In other experiments the Ca2+ in the hypoxic buffer was reduced from 1.3 to 0.1 mM. After 30-120 min of hypoxia, ventricular muscle was assayed for ATP, creatine phosphate, Ca, and Na, and the perfusion defect was established. Resting tension was recorded before and throughout the hypoxic perfusion. Sixty minutes of perfusion with 1.3 mM Ca2+ glucose-free hypoxic buffer caused the tissue Ca to increase (P less than 0.01). Resting tension increased by 7.9 +/- 0.6 g (P less than 0.01). Sixty minutes of perfusion with 0.1 mM Ca2+ glucose-free hypoxic buffer failed to cause an increase in tissue Ca, but resting tension increased (P less than 0.01). During perfusion with glucose-free hypoxic buffer containing 2.6 mM Ca2+ and 30 mM BDM, resting tension remained low for up to 120 min, but after 60 min Ca accumulation occurred. After 120 min of BDM-hypoxic perfusion, tissue Ca reached 11.8 +/- 0.9 mumol/g dry wt. With or without BDM, hypoxia caused an early increase in tissue Na ahead of any increase in tissue Ca.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1988

The stunned myocardium: effect of electrical and mechanical arrest and osmolarity.

After relatively short periods of ischemia, reperfusion for several hours, or even days, is required to facilitate complete recovery of the ATP stores and mechanical function. The term "stunned" has been applied to these hearts. In the present experiments, isolated, spontaneously beating and electrically paced rat hearts were made ischemic for 10 min and then reperfused with Krebs-Henseleit buffer (KH) for up to 30 min. On reperfusion, functional recovery was impaired and the inotropic effect of Ca2+ blunted. In these experiments, the effect of a period of electrical and/or mechanical quiescence before the ischemic episode was investigated. Electrical quiescence was obtained by raising the KH K+ concentration, whereas mechanical without electrical quiescence was obtained by lowering the KH Ca2+ concentration or adding 2,3-butanedione monoxime (BDM). Mechanical arrest caused by low Ca2+ perfusion before ischemia failed to improve functional recovery on reperfusion. However, introducing a high K+ perfusate or BDM for a few minutes before ischemia significantly improved the recovery during reperfusion. This improvement was neither caused by energy preservation nor an altered "reflow area". The improvement may be caused by the increased osmolarity of KH containing high K+ or BDM, since adding 10 mM sucrose to KH for an equivalent time before ischemia improved recovery and abolished the blunted inotropic effect of Ca2+.

Animals↗