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Biomedical subjects

J Thomas

Publications and source records attributed to J Thomas.

At least 469 records · Page 26Linked to original sources
PubMed1991

Cognitive effects of psychostimulant medication in hyperactive children.

Hyperactive and normal children were given a test of selective attention (Stroop test) and a neurocognitive test sensitive to a functional deficit of prefrontal cortex (Wisconsin Card Sorting Test). Hyperactive children showed significant deficits on both measures. After a year of psychostimulant medication, the hyperactive children all showed clinical and neurocognitive improvement, but continued to show a selective attention deficit compared with normal children. The results indicate a dissociation between the cognitive processes measured by the Wisconsin test and selective attention as measured by the Stroop, and that the selective attention deficit is more resistant to psychostimulant intervention.

Attention↗
PubMed1991

Castration alters susceptibility of male rats to specific seizures.

Studies in female rats indicate that estrogen reduction has both pro- and anticonvulsant effects on seizures, but that the respective effects are limited to specific types of seizures at selected doses of picrotoxin. This study was conducted to see if testosterone reduction had parallel effects on seizure susceptibility in males. Male rats were given castration or sham operations and allowed 3 weeks to recover. The latencies to myoclonic, focal, akinetic, and generalized tonic-clonic (GTC) seizures were scored in independent groups of sham-operated or castrated males after injection with picrotoxin (3.5-7.5 mg/kg). The results showed that castrated males had significantly shorter latencies to GTC seizures than sham-operated males at the 3.5 mg/kg and 5.5 mg/kg doses of picrotoxin. There were no significant differences in the latencies to myoclonic, focal, or akinetic seizures between the two surgical groups. The findings suggest that, unlike endogenous estrogen, endogenous testosterone exerts only an anticonvulsant effect and that the effect is limited to GTC seizures.

Animals↗
PubMed1991

Allylglycine-induced seizures in male and female rats.

The possibility that a sex difference in gamma-aminobutyric acid (GABA) activity might be an underlying cause of the previously reported sex differences in picrotoxin-induced seizures was investigated. Male and female rats were injected (IP) with the GABA antagonist, L-allylglycine (100, 150, 200, or 250 mg/kg), and observed for behavioral signs of five categories of seizures induced by picrotoxin: myoclonic, focal, generalized tonic extension, generalized clonic, and generalized seizures with tonic and clonic components. The latency to the first occurrence of each seizure category was scored. Of the five categories of seizures investigated, only focal and generalized tonic extension seizures were observed after allylglycine in the doses tested. Female rats were significantly more susceptible than male rats to allylglycine-induced focal (p less than 0.007) and generalized tonic extension (p less than 0.05) seizures. The results suggest that male-female differences in presynaptic GABA activity may have relevance for sex differences in the occurrence of focal and tonic extension seizures. Differences in the seizure profiles associated with allylglycine and picrotoxin suggests that pre- and postsynaptic antagonism of GABA activity may have different consequences for specific seizure categories and the sex differences associated with those categories.

Allylglycine↗
PubMed1991

Cytogenetic characterization of three cases of unusual B-cell non-Hodgkin's lymphoma.

We report the cytogenetic results in three cases of B-cell non-Hodgkin's lymphomas with morphologic and immunophenotypic features compatible with a non-follicle center cell lymphoma. In all cases, a chromosome breakpoint at 14q32 and structural abnormalities of 1p were found. Increased copies of chromosome segment 12q and structural rearrangements of chromosome 6 were found in two cases. Translocation (14;18)(q32;q21) with rearrangement of bcl-2 was found in one case. These lymphomas have a perifollicular growth pattern and IgM+, IgD+, CD10-, and CD22+ immunophenotype features typical of non-follicle center cell lymphomas and probably belong to the follicle mantle lymphomas described recently. Little cytogenetic data about this group of lymphomas is available, possibly because in the Working Formulation for the Classification of Lymphomas they are not separated from follicle center cell lymphomas.

Adult↗
PubMed1991

High dose hyperfractionated radiotherapy in the treatment of extremity soft tissue sarcomas.

A hyperfractionated radiotherapy schedule has been evaluated in the treatment of 29 adults with limb or limb girdle soft tissue sarcomas. The objective was to increase the total administered dose and possibly improve local control, without increasing late normal tissue damage. Twice daily 1.25 Gy fractions (with a minimum interval of 6 h) have been given over 5 to 6 weeks to 12 patients pre-operatively, 10 post-operatively and 7 palliatively. Five patients received 62.5 Gy in 5 weeks pre-operatively and 3 palliatively. Nineteen of the remaining 21 patients received 75 Gy in 6 weeks with a field size reduction after 5 weeks. Sixteen of 29 tumours were situated in the thigh and only 2 were in the upper limb. Twenty were of high grade. The mean tumour size of those treated radically was 13.1 cm (range 5 to 40 cm). Sixteen patients (76%) given 75 Gy developed moderate or severe skin erythema maximal at 5 weeks. Despite the large field sizes used (mean phase one of 34.5 cm, and phase two of 22.8 cm) only 2 patients failed to complete the planned treatment because of the severity of these reactions. Two other patients developed partial wound breakdowns after the end of treatment--both healing spontaneously. Fourteen patients developed an area of moist desquamation--11 mild, 2 moderate and one severe. There have been four late wound breakdowns requiring surgical intervention; all have since healed well. The median follow up is short at 556 days. Ten of 19 evaluable patients have developed moderate/severe induration, 5/19 mild and 4/19 none.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Low-dose total body irradiation versus combination chemotherapy for lymphomas with follicular growth pattern.

The treatment of Non-Hodgkin's lymphomas with follicular growth pattern and advanced stage of disease remains controversial. Treatments varying from no initial treatment up to aggressive combination chemotherapy have been advocated. The EORTC Lymphoma Cooperative Group has performed a randomized prospective trial comparing short duration low dose total body irradiation (TBI) vs combination chemotherapy (CHVmP) + consolidation radiotherapy. Ninety-three patients were entered; of 84 evaluable patients, 44 received TBI and 40 CHVmP. Complete remission (CR) rates were 36%--TBI and 55%--CHVmP, but overall response rates were identical, 76 versus 69%. No significant difference in freedom from progression or survival was observed. No unexpected toxicity was seen. Although numbers are small, we cannot conclude that aggressive combination chemo-radiotherapy resulted in a better survival. Our analysis confirms that there is a constant risk of relapse. Other approaches should be explored if survival benefit is the ultimate goal in treatment of this patient population.

Adolescent↗
PubMed1991

Assessing daily management of childhood diabetes using 24-hour recall interviews: reliability and stability.

Conducted 24-hr recall interviews concerning daily diabetes management with seventy-eight 6- to 19-year-old patients and their parents. Patients and parents were interviewed independently nine times over 3 months. Data obtained were used to construct 13 adherence measures. All measures yielded statistically significant estimates of parent-child concordance. Parent-child agreement was higher for weekday versus weekend behaviors and when based on nine versus three interviews. For the sample as a whole, parent-child concordance remained stable over the course of the study. Compared to the older patients, the 6- to 9-year-olds exhibited poorer parent-child agreement on measures involving time (e.g., injection and exercise-duration measures). This deficit disappeared, however, as the children became more practiced with the interview procedure. The dietary and glucose-testing measures exhibited moderate stability over the 3-month study. Lower stability estimates were obtained for the exercise and injection measures.

Activities of Daily Living↗
PubMed1991

Superiority of second over first generation chemotherapy in a randomized trial for stage III-IV intermediate and high-grade non-Hodgkin's lymphoma (NHL): the 1980-1985 EORTC trial. The EORTC Lymphoma Group.

A first-generation CHOP-like cyclic combination chemotherapy (CT) regimen using cyclophosphamide 600 mg/m2 IV d1, hydroxorubicin (doxorubicin) 50 mg/m2 IV d1, VM26 60 mg/m2 IV d1, and prednisone 40 mg/m2 PO d1-5 (CHVmP) was compared to a second-generation combination wherein vincristine 1.4 mg/m2 IV and bleomycin 6 mg/m2 IM/IV were added at mid-interval (d15) to the former drugs (CHVmP + VB) in the treatment of intermediate- and high-grade malignant NHL. From April 1980 to January 1986, 141 eligible patients with stage III-IV unfavorable histologies (except T lymphoblastic NHL) entered this EORTC randomized trial. In both arms adjuvant radiotherapy (30 Gy) was given in instances of bulky or residual disease. In all patient subsets the outcome favored the second-generation regimen. The difference was even greater in patients with Diffuse Large Cell Lymphoma (DLCL). At 5 years, overall survival was 53% with CHVmP + VB versus 29% (p = 0.002). The advantage was due to a higher complete remission (CR) rate (80% versus 50%, p = 0.01). Indeed, once CR was achieved the relapse-free survival (RFS) was not significantly influenced (59% versus 49%). No significant additional toxicity could be attributed to vincristine and bleomycin. This study demonstrates a clear benefit for intermediate- and high-risk malignant NHL and particularly DLCL from intercalating non-myelotoxic drugs at mid-cycle intervals, without adverse effects.

Adolescent↗
PubMed1991

A 72-kD B cell-associated surface glycoprotein expressed at high levels in hairy cell leukaemia and plasma cell neoplasms.

The present paper describes two new MoAbs, GHI/75 and VMP55, which were raised against a glycoprotein enriched lysate of hairy cell leukaemia. These antibodies recognized a new antigen of 72 kD (unreduced) and 83 kD (reduced) molecular weight. GHI/75 and VMP55 gave very strong staining of plasma cells, moderate labelling of circulating B cells but only weak staining of monocytes, some tissue macrophages and lymphoid cells. Neither antibody reacted with neutrophils or any non-haematopoietic cells. Both antibodies, however, strongly labelled the tumour cells in hairy cell leukaemia, multiple myeloma, plasmacytoma and lymphoplasmacytic lymphomas. No staining was seen of the neoplastic cells in Hodgkin's disease, myeloid leukaemia or T cell lymphomas. The two antibodies, GHI/75 and VMP55, may be of value in the differential diagnosis of hairy cell leukaemias and plasma cell neoplasms. In addition, the ease with which their antigen can be purified provides the possibility for a detailed study of this molecule.

Antibodies, Monoclonal↗
PubMed1991

Coronary artery constriction is enhanced with nicotine and propranolol, particularly after endothelial damage.

Coronary artery ring preparations from sheep were used for in vitro assessment of isometric tension after stimulation with adrenaline (NA), serotonin (5-HT) and nicotine (NC). From concentration-response curves the following observations were made on potency of agonist: 5-HT greater than NC greater than NA and efficacy: 5-HT = NC greater than NA. Removal of the intima increased sensitivity to stimulation with NA and 5-HT (lower EC50 values) and augmented the maximal response. Preincubation of the vessels with NC and propranolol (PR) resulted in a leftward shift of the concentration-response curves to NA and 5-HT. Sensitivity and maximal response to NA and 5-HT were further enhanced by endothelial removal and pretreatment with NC and PR. It can be concluded that vasoconstriction to NA and 5-HT is enhanced by nicotine (smoking) and administration of beta-blockers (propranolol), particularly in coronary arteries with endothelial damage.

Adrenergic beta-Antagonists↗
PubMed1991

The frequency and significance of ECG changes after transurethral prostate resection.

Although many clinicians routinely recommend a base-line preoperative electrocardiogram (ECG) and obtain frequent postoperative ECGs to screen for myocardial infarction or ischemia, the diagnostic utility of screening perioperative ECGs is unknown. The present analysis evaluates the sensitivity and specificity of the perioperative ECG and examines its value as a predictor of early postoperative cardiac events and outcomes during the postoperative year. ECGs obtained preoperatively and on the first 3 postoperative days in 206 men undergoing transurethral prostate resection were analyzed using the Minnesota Code. The occurrence of cardiac events during the operative stay was assessed by measurement of the cardiospecific MB creatine kinase isoenzyme on the first 3 postoperative days and review of the entire clinical course. Twenty-one percent of patients developed postoperative ECG changes, mostly involving the T wave; none had cardiac symptoms or sustained creatine kinase MB elevation. Changes were not significantly more common in men known to have coronary disease. The single patient who had a perioperative myocardial infarction confirmed by enzymes had no codable ECG changes. The specificity of any ECG change for perioperative infarction was 78%; of ST segment changes only, 95%. Only one of the patients (2%) who had postoperative ECG changes had a cardiac event in the year after surgery. Routine perioperative ECGs is of little diagnostic/predictive utility in situations in which the incidence of perioperative myocardial infarction is low.

Aged↗
PubMed1991

Insertion of part of an intron into the 5' untranslated region of a Caenorhabditis elegans gene converts it into a trans-spliced gene.

In nematodes, the RNA products of some genes are trans-spliced to a 22-nucleotide spliced leader (SL), while the RNA products of other genes are not. In Caenorhabditis elegans, there are two SLs, SL1 and SL2, donated by two distinct small nuclear ribonucleoprotein particles in a process functionally quite similar to nuclear intron removal. We demonstrate here that it is possible to convert a non-trans-spliced gene into a trans-spliced gene by placement of an intron missing only the 5' splice site into the 5' untranslated region. Stable transgenic strains were isolated expressing a gene in which 69 nucleotides of a vit-5 intron, including the 3' splice site, were inserted into the 5' untranslated region of a vit-2/vit-6 fusion gene. The RNA product of this gene was examined by primer extension and PCR amplification. Although the vit-2/vit-6 transgene product is not normally trans-spliced, the majority of transcripts from this altered gene were trans-spliced to SL1. We termed the region of a trans-spliced mRNA precursor between the 5' end and the first 3' splice site an "outron." Our results suggest that if a transcript begins with intronlike sequence followed by a 3' splice site, this alone may constitute an outron and be sufficient to demarcate a transcript as a trans-splice acceptor. These findings leave open the possibility that specific sequences are required to increase the efficiency of trans-splicing.

Animals↗
PubMed1991

The value of hospital chaplains: patient perspectives.

Reports the results of a questionnaire mailed to insurance claimants (N = 2480) recently discharged from a hospital. Analyzes the results and concludes from the data that patients place high value on pastoral services. Suggests that both hospital administrators and chaplains make sure that adequate attention be given to serving patient families, long-stay and repeated admission patients, and to the patients' demonstrated need for frequent visits, particularly in these times of rapid changes in condensing hospital stays.

Chaplaincy Service, Hospital↗
PubMed1991

Improved xenograft survival with continuous infusion deoxyspergualin and RATG.

The critical shortage of available donor organs is the major limit to current allogeneic transplantation. Xenografting has the potential to overcome this difficult problem. Suppressing the vigorous rejection response remains a major obstacle to the clinical application of xenografting, 15-Deoxyspergualin (DOSP), a potent new immunosuppressive agent has been shown to be effective in allogeneic and xenogeneic experimental models. This study tests DOSP in combination with rabbit antithymocyte globulin (RATG) in the hamster-to-rat cardiac xenograft. Results show that combination therapy with DOSP/RATG was superior to treatment with either agent alone (p less than .05). Optimal graft prolongation (20.9 days versus control of 3.1 days, p less than .05) was achieved with combination therapy of RATG and DOSP 2.5 mg/kg day-1 by continuous infusion.

Animals↗
PubMed1991

Patient and family perceptions of hospital chaplains.

While most hospitals provide chaplaincy services for patients, families, and staff, these services are seldom studied and their contribution is poorly understood. A questionnaire created by the College of Chaplains of the American Protestant Health Association was mailed by an insurance company to patients recently dismissed from the hospital, requesting evaluation of three non-medical services (social services, chaplaincy, and patient representatives) and how well the spiritual needs for support/counseling, prayer, and sacraments were met. Responses revealed that, in comparison to the other two non-medical services, patients receive more visits from chaplains, evaluate these visits as more important (p less than 0.000), and report that these visits meet their expectations more highly (p less than 0.000). Regression analyses demonstrate that when the chaplain meets the patient's need for support/counseling, the respondent is more likely to select the hospital again (p = 0.04) and recommend it to others (p = 0.05). Similarly, when chaplains meet the family's need for support/counseling, the respondent is likely to choose the hospital again. Since chaplains clearly make an important contribution to patients, their families, and the hospital, administrators should review the adequacy of their chaplaincy services in the light of these data.

Attitude to Health↗