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Biomedical subjects

J Thomas

Publications and source records attributed to J Thomas.

At least 433 records · Page 24Linked to original sources
PubMed1992

Coronary angioplasty of chronic occlusions: factors predictive of procedural success.

In a retrospective study of 365 chronic total occlusions that were submitted for angioplasty, we studied the influence of 27 clinical, morphologic, and procedural variables as possible predictors of successful outcomes. Success rate was shown to be significantly influenced by the following variables: operator experience (41% in early patients, first 6 months; 73% in late patients, last 6 months of entire series; p less than 0.001), duration of occlusion (less than or equal to 1 month, 89%; 1 to 3 months 87%; greater than or equal to 3 months 45%; unknown 60%; p less than 0.001), morphology of occlusion (tapered, 83%; abrupt, 51%), length of occlusion (less than or equal to 15 mm, 71%; greater than 15 mm, 60%; p less than 0.001), and bridging collaterals (present, 29%; absent, 67%; p less than 0.001). None of the other clinical, angiographic, or procedural variables correlated with the success rate of coronary angioplasty. The calculated probability for an experienced operator (greater than 100 occlusions attempted) to successfully open an occlusion with favorable morphology (less than or equal to 1 month old, short, tapered, without bridging collaterals) is 99%. An attempt by the same operator to open an occlusion with unfavorable structure (greater than or equal to 3 months old, long, untapered) has only 47% probability of success. The probability increases to 84% when the occlusion is tapered. We concluded that in addition to the duration and the length of occlusion, tapered morphology, bridging collaterals, and operator experience can predict successful angioplasty in chronic total coronary occlusion.

Aged↗
PubMed1992

Alanine and hyperosmolarity are responsible for the stimulation of cardiomyocyte glucose transport by samples containing a glucose tolerance factor.

Low-molecular-weight, cationic samples, that were previously reported to contain a glucose tolerance factor, were obtained by partial purification from yeast extract. These samples increased the rate of glucose transport in isolated cardiomyocytes 2.0- to 2.5-fold. A further purification by gel filtration led to the separation of two active components that were identified as (i) L-alanine and (ii) an elevated osmolarity. Moreover, the effect of partially purified fractions (before gel filtration) (i) was decreased upon alanine depletion with alanine dehydrogenase and (ii) was mimicked by the additive action of alanine and of a hyperosmolar medium. These findings indicate that the effect of this partially purified material is not accounted for by a putative glucose tolerance factor. Interestingly, alanine elicited its effect at concentrations that correspond to physiological plasma values, which suggests that this amino acid might be involved in the regulation of glucose transport in cardiomyocytes. Furthermore, the effect of alanine was prevented by DL-cycloserine (1 mM) or aminooxyacetate (1 mM), but not by cycloheximide (35 microM), indicating that (a) transamination reaction(s), but not protein synthesis, is required.

Adipose Tissue↗
PubMed1992

Percutaneous transluminal coronary angioplasty in patients aged 70 years and older: immediate and long-term results.

We analyzed all coronary angioplasty procedures performed in patients aged greater than 70 yr since 1987. There were a total of 92 patients with a mean age of 74 +/- 4 yr (range 70-82). The clinical diagnosis was unstable angina in 79%. Single-vessel disease was present in 41%, double-vessel in 29% and triple-vessel in 30% of patients. A left ventricular ejection fraction of less than 40% was present in 18 patients. Angioplasty was attempted on one vessel in 52 patients (56%), on two vessels in 29 patients (32%) and in three vessels in 10 patients (11%). Angiographic success was achieved in 96% of stenoses and in 53% of chronic total occlusions attempted. Complete revascularization was achieved in 56% of patients. Complications included three patients (3.2%) who underwent emergency coronary artery bypass grafting, 1 patient (1.1%) who sustained a myocardial infarction and 5 patients (5.4%) who died. During hospitalization, which averaged 3 +/- 2 days, 1 patients sustained reversible renal failure and 5 patients required blood transfusion for a large groin hematoma. Clinical success at discharge was 83%. At a mean follow-up of 13 months (range 3-45 months), symptomatic improvement was observed in 59 of the 76 patients who had achieved clinical success, with 42 of these patients (55%) being asymptomatic. The following clinical events occurred: myocardial infarction in 1 patient, new percutaneous transluminal coronary angioplasty in 9 and 3 patients died of cardiac reasons.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Phase II study of cytarabine in Hodgkin's disease. The EORTC Lymphoma Cooperative Group.

Cytarabine was administered to 24 patients with previously treated Hodgkin's disease in the EORTC Lymphoma Cooperative Group. The drug was administered at the dose of 80 mg/m2 subcutaneously twice a day on 5 consecutive days every 3 weeks. The overall response rate was 17.6% (3 responses among 17 evaluable patients) with a short duration (2-6 months). The main toxicity was myelosuppression. Our experience in the EORTC Lymphoma Cooperative Group could not demonstrate a significant activity at this dose and schedule in Hodgkin's disease.

Adult↗
PubMed1992

Comparative study of certified reference materials and quality control materials for the quality assurance of blood-lead determination.

In order to ensure a high standard in the analytical methods used to determine lead in blood, reference materials, quality control materials and several quality assessment schemes exist. However, since 1988 the blood lead level in the European Community has decreased owing to a decline in environmental and occupational exposure; consequently there is a need for certified reference materials (CRMs) at low level. A study of the biological CRMs for blood lead, CRMs 194-196 from the European Community Bureau of Reference (BCR) and the quality control materials STE 901-906 from Nyegaard A/S, and AMI B601-B604 and AMI B701-B705 from the Danish National Institute of Occupational Health (AMI), was made in order to evaluate the control materials AMI B701-B705 against the CRMs 194-196, and to verify the homogeneity and influence of the biological matrix of commercially available blood-lead quality control materials. Internal quality control data were collected and an interlaboratory study was carried out on lyophilized human blood versus lyophilized bovine blood certified for lead. The calculated standard deviations for the BCR CRMs were comparable to the standard deviations for AMI control materials, although the biological matrix was different. No significant difference was demonstrated between the blood-lead levels certified by BCR in 1985 and the levels measured by AMI in 1991, indicating the homogeneity and stability of the lyophilized materials. All analytical results were obtained from selected international laboratories by using atomic absorption spectrometry and anodic stripping voltammetry. The study emphasizes the need for CRMs, control materials and quality assessment schemes for trace elements in biological fluids.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

The development of a posttransplant TLI treatment strategy that promotes organ allograft acceptance without chronic immunosuppression.

The effectiveness of fractionated TLI in promoting allograft tolerance without chronic drug therapy is well established experimentally. TLI has not been widely applied in clinical transplantation, largely due to logistic and medical limitations of pretransplant TLI conditioning. Potential use of posttransplant TLI (PT-TLI) has not been critically evaluated. In this study we investigated PT-TLI in combination with rabbit antithymocyte globulin (RATG) in the absence of chronic immunosuppressive drugs as a strategy for inducing long-term kidney allograft acceptance. Recipients were studied with and without infusion of DR-CD3- donor bone marrow cells (DBMC). Normal rhesus monkeys, which received no pretransplant treatment, underwent bilateral intrinsic nephrectomy and splenectomy at the time of transplantation. RATG was administered daily for 3-5 consecutive days beginning on day 0. A total dose of 500-625 cGy of fractionated TLI was given in 4-5 treatments at 125 cGy per day beginning on day +1. Whereas neither PT-TLI nor RATG monotherapy induced long-term graft acceptance in splenectomized recipients, the combination of these modalities was remarkable in promoting long-term allograft acceptance without immunosuppressive drug therapy. Of 4 recipients given RATG x 5, splenectomy and PT-TLI, all were free of acute rejection. Of these, 3/4 had graft survivals greater than 100 days, 2/4 were greater than 150 days and 1/4 greater than 365 days. Of 5 recipients given this treatment plus an infusion of DR-CD3-DBMC, 4/5 grafts survived greater than 150 days and 3/5 still have normal functioning grafts at greater than 365 days. PT-TLI accentuated and prolonged changes in PBL subpopulations that were initially affected by RATG. Depressed levels of CD3+ cells were present for 4-5 months, with large numbers of circulating CD4+CD3- and especially CD8+ CD3- cells. In addition, antibody responses to RATG and alloantigens were suppressed in PT-TLI-treated recipients. Overall, the combination of PT-TLI, splenectomy, and RATG was found to be effective in promoting long-term allograft acceptance without chronic immunosuppressive drug therapy. The infusion of DR-CD3- DBMC in recipients treated with PT-TLI, RATG and splenectomy appeared to further increase the incidence of stable long-term survivors. If infectious complications can be improved, this approach may provide a clinically applicable posttransplant treatment strategy for inducing functional allograft tolerance.

Animals↗
PubMed1992

Chromosome 11q rearrangements in B non Hodgkin's lymphoma.

The clinical features, morphology and immunophenotype of 20 cases of B non Hodgkin's lymphoma (B-NHL) with chromosome abnormalities involving 11q13-14 were studied, to determine if this abnormality was closely associated with a specific sub-type of B-NHL. A t(11;14)(q13;q32) was found in 11 cases of intermediately differentiated lymphocytic lymphoma (IDLL). A breakpoint in the major translocation cluster of the BCL-1 locus was found in six of these cases. These patients were male with lymphomatous involvement of the bone marrow, marked splenomegaly and frequently had mucosa associated lymphoid tissue involvement. One patient with IDLL had a t(8;11)(p21;q13) and a rearranged BCL-1 locus, suggesting that this may be a variant of t(11;14)(q13;q32). Diagnoses of IDLL, chronic lymphocytic leukaemia, lymphoplasmacytic lymphoma and monocytoid B cell lymphoma were made in all but one of the remaining cases. These cases had either a translocation involving 11q13-14 and various partner chromosomes or an 11q13 deletion. This study demonstrates that 11q abnormalities occur mainly in a group of low-grade B-NHL of non follicle centre cell lineage.

Aged↗
PubMed1992

Inhibition through negative priming with Stroop stimuli in schizophrenia.

Stroop stimuli were used to measure the negative priming effect in eight positive and 10 negative schizophrenics, 21 depressive and 35 healthy control subjects in order to test hypotheses of insufficient versus persistent cognitive inhibition in schizophrenia. Data show that schizophrenics do not increase their response times to suppressor Stroop items compared to identical but neutral Stroop stimuli because the insufficiency of their inhibitory processes weakens the distractor-suppression effect. However, pre-exposure of the lexical distractor can compensate for insufficient inhibitory mechanisms in positive but not negative schizophrenics, suggesting more severe deterioration in the latter. Depressed subjects showed a slower development of cognitive inhibition. The results suggest important differences in the temporal evolution of inhibitory processes, and are discussed in terms of Hemsley's (1977) and Frith's (1979) theories.

Adult↗
PubMed1992

Results of coronary angioplasty in patients aged 75 years and older.

We studied a group of 47 patients greater than or equal to 75 years old. The mean age was 77 +/- 1.5 years and there were 28 (60 percent) male patients. Multivessel disease was present in 72 percent. Angioplasty was successful in 93 percent of 90 stenoses and in 30 percent of ten total occlusions. Single vessel angioplasty was done in 53 percent of patients, double vessel in 28 percent and triple vessel in 19 percent. Incomplete or absent revascularization was present in 47 percent and 9 percent, respectively. Primary clinical success was accomplished in all patients with single vessel disease; in 85 percent of patients with double vessel disease, and in only 52 percent of patients with triple vessel disease. Complications were highest in patients with triple vessel disease: 14 percent mortality and 5 percent emergency CABG. The follow-up at one year showed 91 percent survival. The PTCA is a valid alternative method of revascularization in elderly patients with single and double vessel disease. The results in triple vessel disease are less encouraging.

Age Factors↗
PubMed1992

Price indexes for pharmaceuticals used by the elderly.

The analysis presented in this report was undertaken to identify those drug entities that account for a significant proportion of the retail expenditures for prescription drugs used by the elderly. Commercial data bases were used to develop fixed weight Laspeyres price indexes based specifically on drugs used in the elderly population. The indexes provide the capability to analyze price trends for drug groupings that are not possible with the producer price index (PPI) or the Consumer Price Index (CPI). From 1981 through 1988, the average annual rate of increase in manufacturers' prices was 9.1 percent, and retail prices increased at an average annual rate of 6.6 percent. The indexes represent potentially powerful tools in analyzing drug price trends, an important component of drug program expenditure forecasting and management.

Aged↗
PubMed1992

Giant cystosarcoma phyllodes of the prostate associated with adenocarcinoma.

Cystosarcoma phyllodes of the prostate is a rare neoplasm, occurring in adult men. It closely resembles the not uncommon tumor of the female breast and usually behaves in a similar manner. This case of benign cystosarcoma phyllodes of the prostate occurred in a 53-year-old man who presented with increasing abdominal girth and underwent exploratory laparotomy and removal of the 11.2-kg tumor. It was remarkable for its very large size and the presence of foci of well-differentiated adenocarcinoma, prostatic acinar type. The glandular epithelium of both the phyllodes tumor and the carcinoma were immunoreactive for cytokeratin, epithelial membrane antigen, prostate-specific antigen, and prostate-specific acid phosphatase. The presence of typical prostatic type adenocarcinoma and this immunoreactivity pattern strongly supports a prostatic origin for this rare neoplasm.

Adenocarcinoma↗
PubMed1992

Serum and erythrocyte magnesium concentrations and migraine.

Most people suffering from migraine present a hypersensitivity of the cervico-facial muscles, which may be linked to magnesium deficit. This paper describes a comparative study of serum and erythrocyte magnesium levels in 79 migraine patients and 55 controls. Serum magnesium did not differ significantly in either group, but some values were quite low. On the other hand, there was a significantly greater erythrocyte magnesium deficit in persons suffering from migraine than in controls (in both female and male subjects). This fact correlates with the improved state of migraine patients (already ascertained in earlier studies) following treatment consisting of the intake of magnesium-rich water. The findings support the hypothesis of a magnesium deficit in people suffering from migraine and raise the problem of the relationship between migraine and other pathologies, including chronic magnesium deficit, latent tetany due to magnesium deficit, mitral valve prolapse, and allergy.

Adolescent↗