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Biomedical subjects

G Patterson

Publications and source records attributed to G Patterson.

30 records · Page 2Linked to original sources
PubMed1993

Cytokine gene expression in human lung transplant recipients.

The polymerase chain reaction was used to evaluate cytokine gene expression in bronchoalveolar lavage (BAL) cells and peripheral blood leukocytes in 31 human lung transplant recipients. All patients were maintained on a triple immunosuppression regimen consisting of CsA, AZA, and prednisone. Posttransplant survival ranged from 0.5 to 100.5 months (mean = 16.3 months). Cytokines IL-1 alpha, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, TNF-beta, and IFN-gamma were studied. In BAL, transcripts for IL-1 alpha, IL-7, IL-8, and TNF-beta were found in over 60% of samples and those for IL-5, IL-6, and IFN-gamma in 40-50%, while IL-2 and IL-4 mRNA were rarely found (< 20%). Considerable variation in the frequency of cytokine gene expression between BAL and peripheral blood was observed. When analyzed for the presence of acute pulmonary allograft rejection (without infection), transcripts for IL-4 and IL-6 in BAL demonstrated the greatest increase in frequency compared with nil rejection (P = 0.07 and P = 0.17, respectively). Pulmonary infection (without rejection) was associated with a modest increase in the expression of genes for IL-1 alpha and IFN-gamma (> 10%). Transcripts for IL-4 were not found in association with pulmonary infection, suggesting that this cytokine may be useful as a discriminatory rejection marker.

Adolescent↗
PubMed1990

On the development of an integrated computer system for cephalometric analyses.

This paper describes a microcomputer based system that integrates image processing and computer graphics techniques to automate the data extraction and storage process in cephalometric analyses. The system increases the consistency of measurements and improves the productivity of surgical and dental staff.

Cephalometry↗
PubMed1990

The effect and optimal time of administration of verapamil on lung preservation.

Calcium channel blockers have recently been shown to improve pulmonary and myocardial preservation. The effect of verapamil on hypothermic lung preservation was investigated using an isolated ventilated rabbit lung perfusion model. In phase 1, preserved lungs were not flushed prior to extraction. Four groups of five animals were studied: group 1 (no verapamil), group 2 (verapamil administration prior to extraction), group 3 (verapamil at reperfusion only), group 4 (verapamil both prior to extraction and at reperfusion). In phase 2, two groups of five animals received pulmonary artery flush with low potassium (4 mmol/L), 2% low-potassium dextran (LPD) solution; group 1 (without verapamil), group 2 (flush and reperfusion with verapamil). As in phase 1, lungs were stored for 30 hr at 10 degrees C prior to reperfusion. In phase 3, the protocol was identical to phase 2, except that the storage time was extended to 48 hr. PO2 (mean +/- SE) of effluent blood in lungs treated with verapamil prior to extraction (122.8 +/- 5.0 mmHg) was significantly increased in comparison with lungs not receiving verapamil (69.0 +/- 3.3 mmHg) or only receiving verapamil at the time of reperfusion (87.1 +/- 11.9 mmHg). Gas exchange after 30 hr storage was equivalent in lungs flushed with LPD with or without verapamil. However verapamil did provide an advantage when preservation times were extended to 48 hr (62.3 +/- 8.5 mmHg, 46.9 +/- 2.3 mmHg). Verapamil administered prior to lung extraction provides better lung function following preservation, but has benefit over LPD flush only with extended periods of preservation (48 hr).

Animals↗
PubMed1985

Xanthine oxidase as a source of free radical damage in myocardial ischemia.

Experiments were performed to determine if xanthine oxidase is a source of free radicals during myocardial ischemia. Open chest dogs were subjected to 1 h of total occlusion of the left anterior descending coronary artery followed by 4 h of reperfusion. Directly after coronary artery occlusion, Ce141 microspheres were injected into the left atrium to mark the ischemic bed. At the end of reperfusion, the hearts were removed and sectioned. Autoradiography determined the ischemic myocardium at risk, and the necrotic zone was determined by triphenyl-tetrazolium staining. Animals were divided into three groups: control, allopurinol (24-h oral pretreatment 400 mg, then 50 mg/kg IV bolus on occlusion); and superoxide dismutase starting with occlusion (15 000 U/kg). The size of the infarct as a percentage of the tissue at risk was: 23.1 +/- 4.1 for the control; 8.7 +/- 1.2 for the allopurinol group; and 5.4 +/- 1.2 for the superoxide dismutase group. The infarcts in the allopurinol and superoxide dismutase groups were significantly smaller than those in the control groups. In a second series of experiments we determined the xanthine oxidase/xanthine dehydrogenase content of dog myocardium. The left anterior descending branch was ligated for 30 min and then biopsies were removed from both the normal and the ischemic regions. Total enzyme content did not differ between the two regions averaging 0.259 U/g protein for the ischemic tissue and 0.225 U/g protein for the normal region. Only 9.8% of the enzyme was in the oxidase form in the normal region while 32.8% was in the oxidase form in the ischemic zone.(ABSTRACT TRUNCATED AT 250 WORDS)

Allopurinol↗
PubMed1984

Post-sepsis prophylaxis in cancer patients.

One hundred children with cancer and bacterial sepsis were observed for one month after completion of antibiotic treatment for subsequent episodes of infection. After satisfactory clinical and bacteriological responses were achieved and antibiotic therapy terminated, 38 of the patients were maintained on trimethoprim--sulfamethoxazole (TMP-SMZ) and 62 did not receive the drug combination. Of the 26 neutropenic patients not receiving TMP-SMZ 23 (88%) had episodes of infection, whereas 4 (36%) of the 11 given the drug had recurrent or re-infection episodes (P = less than 0.001). A difference of similar significance was observed in the non-neutropenic patients. Infections in children in relapse of their malignancy were twice as frequent in those not receiving the drug as in those who received it (P = less than 0.02, greater than 0.01). Of the 19 patients who died during the month of observation, none had received TMP--SMZ. This study shows that the administration of TMP--SMZ after bacterial sepsis reduces the number of infectious episodes in neutropenic and non-neutropenic patients, with the exception of the non-neutropenic patient in remission.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1979

Evaluation of a 5% guanethidine and 0.5% adrenaline mixture (Ganda 5.05) and of a 3% guanethidine and 0.5% adrenaline mixture (Ganda 3.05) in the treatment of open-angle glaucoma.

A trial of a mixture of guanethidine 5% and adrenaline 0.5% (Ganda 5.05) and of guanethidine 3% and adrenaline 0.5% (Ganda 3.05) was conducted on 90 eyes in 53 patients with open-angle glaucoma or ocular hypertension. The cases fell into 5 groups: untreated cases, cases on pilocarpine 1%, on pilocarpine 2%, on pilocarpine 2 to 4% and adrenaline 1%, and on separate guanethidine 5% and adrenaline 1%. Baseline pressures and average pressures on the previous treatment were established. Substitution with Ganda 3.05 or 5.05 was started, and the patients attended 2 weeks, 1 month, 3 months, and 6 months from the start of the trial. Applanation tonometry was carried out at the same time of day. The pupil was measured, ptosis and superficial punctate corneal staining were looked for and evaluated, and the patients were questioned for symptoms of side effects and acceptability. All the eyes that had previously been treated with pilocarpine 1% or 2% presented significantly lower intraocular pressures on Ganda 3.05. The patients on pilocarpine 4% and adrenaline 1% also had lower intraocular pressures on Ganda 5.05, but the significance was less, and the patients on separate guanethidine and adrenaline had a small but not statistically significant drop in pressure. Ptosis and discomfort were evaluated on a subjective scale. Patient acceptability was good. The trial was interrupted in 5 cases for various reasons. Tachyphylaxis and tolerance to the mixtures were not observed in this series.

Clinical Trials as Topic↗
PubMed1975

Relationship between polyene resistance and sterol compositions in Cryptococcus neoformans.

Six mutants of Cryptococcus neoformans resistant to nystatin and pimaricin and three mutants resistant to amphotericin B were isolated by ultraviolet irradiation techniques from two wild-type strains. The major sterols of the wild-type strains were Delta(7)-ergosten-3beta-ol and ergosterol. All six mutants resistant to nystatin and pimaricin showed either loss of ergosterol and concurrent production of Delta(7, 22)-ergostadien-3beta-ol and Delta(7)-ergosten-3beta-ol, or loss of both the wild-type sterols, with production of Delta(8(9))-ergosten-3beta-ol and Delta(5, 8(9), 22)-ergostatrien-3beta-ol. The mutants producing Delta(7, 22)-ergostadien-3beta-ol and Delta(7)-ergosten-3beta-ol showed relatively low levels of resistance to nystatin and pimaricin, whereas the mutants producing Delta(8(9))-ergosten-3beta-ol and Delta(5, 8(0), 22)-ergostatrien-3beta-ol showed a high level of resistance to either drug. Although highly resistant to amphotericin B, however, the three mutants produced sterol compositions identical to those of the wild types, indicating that the strains acquired resistance other than by alteration of the membrane sterols. The mutants producing Delta(8(9)) and Delta(5, 8(9), 22) sterols were not virulent for mice, showed reduced growth rates at 25 C, and failed to grow at 37 C. The other mutants showed a slightly reduced rate of growth both at 25 and 37 C, and the virulence in mice was slightly reduced in comparison with that of the wild types. These comparisons were on gross observations and were not statistically analyzed.

Animals↗
PubMed1968

Detection of Salmonella by a single-culture technique.

Dulcitol-selenite enrichment medium in a motility flask was used for the detection of Salmonella in food. A drop in pH of the dulcitol-selenite enrichment motility broth indicated the presence of Salmonella; this phenomenon was confirmed by fluorescent-antibody staining. A complete correlation was found between fluorescent-antibody staining and recovery on Brilliant Green agar. Testing of 332 samples of 8 different kinds of foods and feeds indicated no significant difference in sensitivity between the new technique and a conventional Salmonella detection technique. The new technique permitted detection of even small numbers of Salmonella in 1 to 2 days.

Alcohols↗