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Biomedical subjects

J Thomas

Publications and source records attributed to J Thomas.

At least 253 records · Page 14Linked to original sources

CHOP is the standard regimen in patients > or = 70 years of age with intermediate-grade and high-grade non-Hodgkin's lymphoma: results of a randomized study of the European Organization for Research and Treatment of Cancer Lymphoma Cooperative Study Group.

PURPOSE: We report the results of a randomized study of the European Organization for Research and Treatment of Cancer (EORTC) Lymphoma Group, which compared a chemotherapy regimen specifically devised for elderly patients, ie, etoposide, mitoxantrone, and prednimustine (VMP), versus the standard regimen of cyclophosphamide, doxorobucin, vincristine, and prednisone (CHOP) in patients older than 70 years of age with intermediate- and high-grade non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: Patients older than 70 years of age with stage II, III, or IV intermediate- and high-grade NHL, with an Eastern Cooperative Oncology Group (ECOG) performance status less than 4 and acceptable cardiac, renal, and liver function were randomized to receive six courses of VMP or six courses of CHOP. Between February 1989 and June 1994, 130 patients aged 70 to 93 years (median, 75) were enrolled and 120 were assessable for response, 60 patients in each arm. RESULTS: Overall objective response rates were 50% and 77% in VMP- and CHOP-treated patients, respectively (P = .01), while complete response (CR) rates were borderline significant (27% v 45%; P = .06). At 2 years, the progression-free survival (PFS) rate was 25% with VMP versus 55% with CHOP (P = .002) and the overall survival (OS) rate was 30% with VMP versus 65% with CHOP (P = .004). Statistically significant more alopecia and neurologic and gastrointestinal toxicities were reported with CHOP. CONCLUSION: CHOP is the standard regimen for patients > or = 70 years of age with stage II to IV intermediate- and high-grade NHL.

Aged↗

Maintenance of remission with human recombinant interferon alfa-2a in patients with stages III and IV low-grade malignant non-Hodgkin's lymphoma. European Organization for Research and Treatment of Cancer Lymphoma Cooperative Group.

PURPOSE: Interferon alfa has shown significant activity in patients with low-grade malignant non-Hodgkin's lymphoma (NHL). In 1985, we initiated a prospective randomized study in which the potential benefit of interferon alfa given as maintenance treatment was investigated after tumor load reduction was achieved with chemoradiotherapy in patients with advanced low-grade malignant non-Hodgkin's lymphoma. PATIENTS AND METHODS: The study involved 347 patients with stage III or IV disease, 315 satisfying the eligibility criteria. All were treated with a regimen of cyclophosphamide, vincristine, and prednisone (CVP) given every 3 weeks for eight cycles. Thereafter, patients were eligible for iceberg irradiation. Finally, all patients were completely restaged, and responding and stable-disease patients were then randomized, 122 to interferon alfa-2a maintenance, 3 million U three times weekly for 1 year; and 120 to no further treatment. RESULTS: Seventy-nine percent of the patients response to CVP, ie, 45% complete remissions (CR) and 34% partial remissions (PR). In the group of randomized patients, the response rate after CVP plus or minus radiotherapy was 90%. As compared with control patients, patients in the interferon (IFN) maintenance group had a tendency toward a prolonged time to progression (TTP) (median, 132 v 87 weeks; P = .054, adjusted for response to CVP). However, overall survival was similar in both groups. Interferon was well tolerated. The median dose of IFN actually received corresponded to 90% of the planned cumulative dose. The treatment had to be stopped because of toxicity in 16 patients (15% of the patients in whom IFN was started). CONCLUSION: Interferon maintenance treatment in the phase of minimal residual disease of patients with advanced low-grade malignant NHL increased TTP at the borderline of statistical significance, without remarkable toxicity. However, overall survival was not influenced.

Adult↗

CAMPATH-1H monoclonal antibody in therapy for previously treated low-grade non-Hodgkin's lymphomas: a phase II multicenter study. European Study Group of CAMPATH-1H Treatment in Low-Grade Non-Hodgkin's Lymphoma.

PURPOSE: CAMPATH-1H is a human immunoglobulin G1 (IgG1) anti-CD52 monoclonal antibody (MAb) that binds to nearly all B-cell and T-cell lymphomas. We report here the results of a multicenter phase II trial of CAMPATH-1H in patients with advanced, low-grade non-Hodgkin's lymphoma (NHL) who were previously treated with chemotherapy. PATIENTS AND METHODS: Fifty patients who had relapsed (n=25) after or were resistant (n = 25) to chemotherapy were treated with CAMPATH-1H 30 mg administered as a 2-hour intravenous (i.v.) infusion three times weekly for a maximum period of 12 weeks. RESULTS: Six patients (14%) with B-cell lymphomas achieved a partial remission (PR). Patients with mycosis fungoides appeared to respond more frequently (50%; four of eight patients, which included two complete remissions [CRs]). Lymphoma cells were rapidly eliminated from blood in 16 of 17 patients (94%). CR in the bone marrow was obtained in 32% of the patients. Lymphoma skin lesions disappeared completely in four of 10 patients and partial regression was obtained in three patients. Lymphadenopathy and splenomegaly were normalized in only 5% and 15% of patients, respectively. Lymphopenia (< 0.5 x 10(9)/L) occurred in all patients. World Health Organization (WHO) grade IV neutropenia occurred in 14 patients (28%). Opportunistic infections were diagnosed in seven patients and nine patients had bacterial septicemia. Death related to infectious complications occurred in three patients. CONCLUSION: CAMPATH-1H had a significant but limited activity in patients with advanced, heavily pretreated NHL. The most pronounced effects were noted in the blood and bone marrow and in patients with mycosis fungoides. The risk for serious infectious complications needs to be considered for severely ill patients who are evaluated for CAMPATH-1H treatment.

Adult↗

Difficulty of a spatial task and sex difference in gains from practice.

The influence of practice on a difficult spatial task in a small sample of 11 men and 16 women was investigated. Participants were tested on a rotated embedded figures task modified from the Gottschaldt Hidden Figure Test prior to being given practice in identifying rotated and nonrotated embedded figures. One week after the pretest and practice session, the posttest was given. In the small sample studied, the number of correctly identified rotated figures on the posttest was significantly increased relative to pretest scores for men and women. However, the tendency for women to score higher than men after practice was not significant.

Adolescent↗

Incidence and time trends in Hodgkin's disease: from parts of the United Kingdom (1984-1993).

Over 3,000 cases of Hodgkin's Disease diagnosed between 1984-93 were used to examine incidence and time trends. These data are part of the Leukaemia Research Fund's specialist Data Collection Study, which is the only large, population-based data set of its type in Europe. The age specific incidence curves showed different patterns for nodular sclerosis contrasted with all other subtypes combined (non-nodular sclerosis). For nodular sclerosis, there was a female excess for young adults, while for non-nodular sclerosis a gradual rise in incidence with age in both sexes was observed. Incidence varied over time, showing a complex pattern with a decreasing trend in males in all Rye-subtypes and no significant change among females diagnosed with nodular sclerosis. These complex patterns of change are different from those seen in other countries. It is concluded that the results provide clear evidence of the heterogeneity of Hodgkin's disease between the sexes and between subtypes, which should be taken into account in future studies.

Adolescent↗

The expression of urokinase-related genes in superficial and invasive transitional cell carcinoma.

Tumor invasion and metastasis is mediated in part by proteolytic enzymes including urokinase plasminogen activator (uPA). The object of this study was to quantitate the molecular expression of urokinase plasminogen activator-related components in human superficial and invasive transitional cell carcinoma tumors (TCC), as well as parental and invasive variant TCC cell lines. We examined 15 invasive and 14 superficial TCC tumors (from a total of 29 patients) and six bladder carcinoma cell lines for the steady state mRNA levels of uPA, the uPA receptor and uPA inhibitor-1 by quantitative RT-PCR normalized to the L7 ribosomal transcript (a housekeeping gene). Transcript levels were expressed in a ratio to the L7 housekeeping transcript. There was a three fold increase in uPA expression in invasive lesions compared to superficial tumors (p < 0.003). In addition, there was a concordant 2.7 fold increase in the uPA receptor transcript in invasive TCC (p < 0.008). However, there was no significant difference in the steady state levels of the PAI-1 mRNA between invasive and superficial tumors. Transcript levels for the urokinase-related genes were similar between normal mucosa and superficial tumors. Cultured cells (parental and invasive variants) were found to express higher levels of the three uPA-related genes overall. Invasive TCC cells selected by serial passage through a Boyden chamber demonstrated higher levels of uPA, uPA receptor and PAI-1 than parental cells (p < 0.05). These data from the human tumor specimens suggest that increased uPA and uPAr expression may be component of the invasive phenotype of TCC lesions.

Carcinoma, Transitional Cell↗

Comparison of axial and instantaneous videokeratographic data in keratoconus and utility in contact lens curvature prediction.

PURPOSE: Instantaneous radius of curvature data in corneal videokeratoscopy better represents corneal shape and local curvature changes in keratoconus than axial maps, especially in the periphery. Knowledge of instantaneous radius is especially important in keratoconus for analysis of the cone apex, which is often decentered. In this study, we quantitatively compared axial and instantaneous displays of videokeratographic data in keratoconus, with emphasis on apex curvature and position. We assessed the utility of instantaneous data for rigid gas permeable (RGP) contact lens curvature selection and compared it with data derived from the original axial displays in keratoconus. METHODS: We performed modern placido-based videokeratography on 35 eyes with clinically diagnosed keratoconus. We derived the apex curvature, the position of the apex relative to the center of the map, and the steep simulated keratometry (SIM-K) reading from axial and instantaneous videokeratographic displays. We also collected the RGP base curves for 28 eyes that were fit with a minimal apical bearing or clearance RGP contact lens. RESULTS: The instantaneous apex was consistently located closer to the center of the map than the axial apex. Means (and standard deviations) for the best fit RGP base curve, axial steep SIM-K, axial apex curvature, instantaneous steep SIM-K, and instantaneous apex curvature were 52.00 D +/- 5.92 D, 50.93 D +/- 5.94 D, 54.81 D +/- 7.14 D, 49.19 D +/- 5.54 D, and 56.86 D +/- 7.89 D, respectively. Statistical comparisons revealed axial steep SIM-K to best represent the RGP base curve for the entire group. Similarly, in the subset of patients with apex decentrations within 1 mm of the map center, the axial steep SIM-K best represented the RGP base curve. In the remaining decentered cone subset, the axial apex curvature best represented the base curve. CONCLUSIONS: Axial and instantaneous maps differ significantly in apical position and apex curvature in keratoconus. Although instantaneous radius may better represent corneal shape, axial curvatures better predict the final RGP base curve in keratoconus patients.

Algorithms↗

Infiltrating papillary thyroid carcinoma: review of 134 cases of papillary carcinoma.

BACKGROUND: Papillary thyroid carcinomas (PTCs) are diagnosed mainly by the features of nuclei of the neoplastic cells. Theoretically, by similarity to other types of carcinoma, infiltrative tumor growth likely distinguishes the thyroid neoplastic lesions with potential of metastasis from those without this capability. METHODS: One hundred thirty-four cases of PTC, consisting of 41 encapsulated tumors and 93 nonencapsulated tumors, were examined for the presence of infiltrating PTC (IPTC), defined by tumor cells infiltrating a desmoplastic or sclerotic stroma. RESULTS: Encapsulated tumors with focal or extensive IPTC and nonencapsulated tumors with focal or extensive IPTC were associated with rates of lymph node metastases of 28%, 42%, 36%, and 65%, respectively. The tall cell variant of PTC was associated with a higher rate of metastasis. There was a small group of tumors without identifiable IPTC, designated as PTC without identifiable infiltrating carcinoma, which included six encapsulated tumors with areas of sclerosis in the capsule and three nonencapsulated tumors consisting of neoplastic cells with optically clear nuclei, nuclear grooves, and intranuclear inclusions in over two thirds of the cell population. Of these lesions, one case developed lymph node metastases. Papillary thyroid tumors without areas of IPTC and exhibiting the nuclear changes described, but in less than two thirds of the tumor cells, did not develop lymph node metastases. CONCLUSIONS: Infiltrating tumor growth is an indicator of malignant behavior in most thyroid papillary neoplastic lesions. The extent of IPTC is likely proportional to the rate of lymph node metastases.

Carcinoma, Papillary↗

Multiple outcome assessment in a study of the cost-effectiveness of clozapine in the treatment of refractory schizophrenia. Department of Veterans Affairs Cooperative Study Group on Clozapine in Refractory Schizophrenia.

OBJECTIVE: To develop new methods for combining results from multiple outcome domains and to demonstrate their application in a study of the cost-effectiveness of clozapine in treating hospitalized patients with refractory schizophrenia. DATA SOURCES/STUDY SETTING: Interview assessments, and administrative utilization and cost data, concerning 423 patients with refractory schizophrenia who had been hospitalized for 30-364 days during the year before study entry, at 15 VA medical centers. STUDY DESIGN: A 12-month double-blind trial compared clozapine (n = 205) and haloperidol (n = 218) in the treatment of refractory schizophrenia. DATA COLLECTION/EXTRACTION METHODS: Data from standard assessment instruments, gathered at baseline and at 6 weeks, and at 3, 6, 9, and 12 months, were used to develop a Composite Health Index for Schizophrenia, a measure that addresses outcome in six domains, weighted by patient or provider preferences. Cumulative improvement was estimated by computing the area under the improvement curve. This measure was then combined with cost data, reflecting consumption of societal resources to estimate incremental cost-effectiveness ratios. PRINCIPAL FINDINGS: Clozapine was significantly more effective than haloperidol on measures of symptoms (p = .02) and side effects (p < .0001), with nonsignificant trends in the positive direction on community role functioning (p = .06), family relationships (p = .23), social relationships (p = .30), and daily activities (p = .20). Clozapine was also more effective than haloperidol on the one-year cumulative Composite Health Index for Schizophrenia (p < .0001 for all weighting schemes). After converting this measure to a 0-1 Worst Health-Good Health Scale analogous to Quality Adjusted Life Years, clozapine was found to yield a small improvement of .049 Worst Health-Good Health Units as compared to an improvement of only .027 Units for haloperidol (p < .0001). Average annual costs were $2,733 lower for clozapine (95% C.I. = -$9,220 to $3,754). Although clozapine was significantly more effective than haloperidol, the summary cost-effectiveness ratio had a wide 95 percent confidence interval ranging from -$431,585 to $177,352. CONCLUSIONS: Methods demonstrate an approach to using conventional disease-specific measures to evaluate the cumulative effectiveness of novel treatments for psychotic disorders and for expressing their economic effect as cost-effectiveness ratios. Among high hospital users with refractory schizophrenia, clozapine is more cost-effective than standard treatment, although the magnitude of its effect is small and there is considerable uncertainty about the cost estimates.

Clozapine↗

A hippocampal GluR5 kainate receptor regulating inhibitory synaptic transmission.

The principal excitatory neurotransmitter in the vertebrate central nervous system, L-glutamate, acts on three classes of ionotripic glutamate receptors, named after the agonists AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxalole-4-propionic acid), NMDA (N-methyl-D-aspartate) and kainate. The development of selective pharmacological agents has led to a detailed understanding of the physiological and pathological roles of AMPA and NMDA receptors. In contrast, the lack of selective kainate receptor ligands has greatly hindered progress in understanding the roles of kainate receptors. Here we describe the effects of a potent and selective agonist, ATPA ((RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazol-4-yl)propanoic acid) and a selective antagonist, LY294486 ((3SR, 4aRS, 6SR, 8aRS)-6-((((1H-tetrazol-5-yl) methyl)oxy)methyl)-1, 2, 3, 4, 4a, 5, 6, 7, 8, 8a-decahydroisoquinoline-3-carboxylic acid), of the GluR5 subtype of kainate receptor. We have used these agents to show that kainate receptors, comprised of or containing GluR5 subunits, regulate synaptic inhibition in the hippocampus, an action that could contribute to the epileptogenic effects of kainate.

Animals↗

A comparison of clozapine and haloperidol in hospitalized patients with refractory schizophrenia. Department of Veterans Affairs Cooperative Study Group on Clozapine in Refractory Schizophrenia.

BACKGROUND: Clozapine, a relatively expensive antipsychotic drug, is widely used to treat patients with refractory schizophrenia. It has a low incidence of extrapyramidal side effects but may cause agranulocytosis. There have been no long-term assessments of its effect on symptoms, social functioning, and the use and cost of health care. METHODS: We conducted a randomized, one-year, double-blind comparative study of clozapine (in 205 patients) and haloperidol (in 218 patients) at 15 Veterans Affairs medical centers. All participants had refractory schizophrenia and had been hospitalized for the disease for 30 to 364 days in the previous year. All patients received case-management and social-rehabilitation services, as clinically indicated. RESULTS: In the clozapine group, 117 patients (57 percent) continued their assigned treatment for the entire year, as compared with 61 (28 percent) of the patients in the haloperidol group (P<0.001). As judged according to the Positive and Negative Syndrome Scale of Schizophrenia, patients in the clozapine group had 5.4 percent lower symptom levels than those in the haloperidol group at all follow-up evaluations (mean score, 79.1 vs. 83.6; P=0.02). The differences on a quality-of-life scale were not significant in the intention-to-treat analysis, but they were significant among patients who did not cross over to the other treatment (P=0.003). Over a one-year period, patients assigned to clozapine had fewer mean days of hospitalization for psychiatric reasons than patients assigned to haloperidol (143.8 vs. 168.1 days, P=0.03) and used more outpatient services (133.6 vs. 97.9 units of service, P=0.03). The total per capita costs to society were high -- $58,151 in the clozapine group and $60,885 in the haloperidol group (P=0.41). The per capita costs of antipsychotic drugs were $3,199 in the clozapine group and $367 in the haloperidol group (P<0.001). Patients assigned to clozapine had less tardive dyskinesia and fewer extrapyramidal side effects. Agranulocytosis developed in three patients in the clozapine group; all recovered fully. CONCLUSIONS: For patients with refractory schizophrenia and high levels of hospital use, clozapine was somewhat more effective than haloperidol and had fewer side effects and similar overall costs.

Adult↗

A Ph-negative chronic myeloid leukemia patient with a non-classical BCR-ABL rearrangement characterized by fluorescence in situ hybridization.

A patient with chronic myeloid leukemia (CML), a normal karyotype and a BCR-ABL rearrangement is presented. Southern blot analysis detected the rearrangement, whereas RT-PCR with b2a2 and b3a2 primers did not. Fluorescence in situ hybridization (FISH) with an ABL probe (9q34.2) and an Mbcr probe (22q11) showed ABL and BCR signals on chromosome 22. Subsequent FISH studies with cosmids mapping to 9q34.3 showed normal hybridization patterns to chromosome 9, suggesting an interstitial insertion of ABL containing DNA sequences into chromosome 22 in this patient. The lack of reciprocal translocation sequences was investigated with RT-PCR, primers a1b and c7. The absence of ABL-BCR gene expression in this and other patients described in the literature with this subtype of Ph-negative CML, does not seem to have an impact on the clinical course of the disease.

Adult↗

Gout and risk for subsequent coronary heart disease. The Meharry-Hopkins Study.

BACKGROUND: Patients with gout are encountered frequently in clinical practice. Previous studies have suggested that hyperuricemia and gout may represent risk factors for coronary heart disease (CHD), the most common cause of death in American men. METHODS: Prospectively collected data from 2 longitudinal cohort studies of former medical students--371 black men in the Meharry Cohort Study and 1181 white men in the Johns Hopkins Precursors Study--were analyzed. The development of gout and of CHD was determined by physician self-report, and validated by using published criteria. The risk for CHD associated with gout was evaluated using Cox proportional hazards analysis. RESULTS: During a median follow-up of 30 years, there were 38 gout cases and 44 CHD events among the Meharry men, and 68 gout cases and 138 CHD events among the Hopkins men. Prior gout was not associated with an increased risk for incident CHD (relative risk = 1.20; 95% confidence interval, 0.37-3.92) among the Meharry men or among the Hopkins men (relative risk = 0.66; 95% confidence interval, 0.24-1.79). Multivariate analysis adjusted for known CHD risk factors did not alter these findings. CONCLUSION: These results, in black and white male physicians, do not suggest a role in men for targeting gout identification in the primary prevention of CHD.

Adult↗

Insulin-induced recruitment of glucose transporter 4 (GLUT4) and GLUT1 in isolated rat cardiac myocytes. Evidence of the existence of different intracellular GLUT4 vesicle populations.

UNLABELLED: Using isolated rat cardiomyocytes we have examined: 1) the effect of insulin on the cellular distribution of glucose transporter 4 (GLUT4) and GLUT1, 2) the total amount of these transporters, and 3) the co-localization of GLUT4, GLUT1, and secretory carrier membrane proteins (SCAMPs) in intracellular membranes. Insulin induced 5.7- and 2.7-fold increases in GLUT4 and GLUT1 at the cell surface, respectively, as determined by the nonpermeant photoaffinity label [3H]2-N-[4(1-azi-2,2,2-trifluoroethyl)benzoyl]-1, 3-bis-(D-mannos-4-yloxy)propyl-2-amine. The total amount of GLUT1, as determined by quantitative Western blot analysis of cell homogenates, was found to represent a substantial fraction ( approximately 30%) of the total glucose transporter content. Intracellular GLUT4-containing vesicles were immunoisolated from low density microsomes by using monoclonal anti-GLUT4 (1F8) or anti-SCAMP antibodies (3F8) coupled to either agarose or acrylamide. With these different immunoisolation conditions two GLUT4 membrane pools were found in nonstimulated cells: one pool with a high proportion of GLUT4 and a low content in GLUT1 and SCAMP 39 (pool 1) and a second GLUT4 pool with a high content of GLUT1 and SCAMP 39 (pool 2). The existence of pool 1 was confirmed by immunotitration of intracellular GLUT4 membranes with 1F8-acrylamide. Acute insulin treatment caused the depletion of GLUT4 in both pools and of GLUT1 and SCAMP 39 in pool 2. IN CONCLUSION: 1) GLUT4 is the major glucose transporter to be recruited to the surface of cardiomyocytes in response to insulin; 2) these cells express a high level of GLUT1; and 3) intracellular GLUT4-containing vesicles consist of at least two populations, which is compatible with recently proposed models of GLUT4 trafficking in adipocytes.

Animals↗