PubMed Health⌕ Search

Biomedical subjects

J Bennett

Publications and source records attributed to J Bennett.

At least 37 records · Page 2Linked to original sources
PubMed1991

The structure of self-reported physical health among the aged in the United States and Japan.

This article attempts to extend the generalizability of a three-dimensional model of self-reported physical health among the aged to a nonwestern culture. Consisting of three interrelated dimensions, chronic illness, functional status, and self-rated health, this model was empirically evaluated by using national data on the aged gathered in the United States and Japan. The three-dimensional specification was found to apply equally well to U.S. and Japanese elderly. In addition to examining the internal structure of this three-dimensional model, the study assessed the model's relationships with a set of selected exogenous variables including age, sex, marital status, and education. The relationships between the selected exogenous variables and physical health dimensions are largely similar in both countries. However, clear differences appeared in at least three instances.

Activities of Daily Living↗
PubMed1991

The treatment of patients with newly diagnosed poor prognosis acute myelogenous leukaemia: response to treatment and treatment failure.

The failure of poor prognosis patients with newly diagnosed AML to enter remission is usually due to two phenomena: a high mortality rate and resistance of the leukaemia to chemotherapy. We conducted a pilot study of a regimen designed to overcome these two types of treatment failure. Patients were carefully selected for therapy on the basis of their likelihood of surviving. Chemotherapy consisted of high dose cytosine arabinoside (HDaraC) with the doses modified on the basis of patient age so as to reduce the risk of toxicity. Finally, daunorubicin was administered only to those patients for whom HDaraC was not likely to produce sufficient antileukaemia effects to produce a remission. The median patient age was 67 years and 69/88 (78%) patients had a history of preleukaemia and/or toxic exposure. Only 11/84 (13%) patients died during remission induction therapy and 40/84 (48%) entered CR. Patients with only one risk factor had a higher CR rate than those with more than one risk factor (56% v. 30%, P = 0.02) and also had longer durations (222 d v. 113.5 d, P = 0.035). Two types of resistance to chemotherapy were observed: 'classical resistance' (the failure of chemotherapy to produce substantial killing of leukaemia cells) and the rapid regrowth of leukaemia cells subsequent to a level of cytoreduction which otherwise would have been sufficient to produce a CR.

Aged↗
PubMed1991

Promoting comprehensive school health programs through summer health promotion conferences.

This study reports on the evaluation of the second North Carolina Healthful Living Institute (HLI), a statewide conference to promote comprehensive school health education. A comparison of year one and year two evaluation results is included. Based on a theoretical framework derived from the theory of diffusion of innovations within organizations, the impact of the HLI was assessed by studying characteristics of school districts sending representatives to the HLI and the composition of teams from each school district, and using pretest and posttest measures of participants' perceptions of the importance of health as a content area and participants' perceptions of the importance of the various components of comprehensive school health. Results indicate the effect of school health promotion conferences is linked to characteristics of school district teams, with the Institute needing to attract more varied teams, and teams from smaller, rural districts.

Adult↗
PubMed1991

Intravenous recombinant interferon beta in patients with recurrent malignant gliomas: a phase I/II study.

A multicenter phase I/II trial of a human recombinant interferon beta (Betaseron; Triton Biosciences, Alameda, CA) was conducted in patients with recurrent glioblastoma and anaplastic astrocytoma in six centers between 1986 and 1988. Betaseron was given intravenously three times per week, starting at 90 x 10(6) IU per dose and escalating by 90 x 10(6) IU every 2 weeks up to a maximum dose of 540 x 10(6) per treatment. All patients had failed prior radiotherapy, and most had failed one or more courses of chemotherapy. Of the 72 patients entered into the protocol, 65 were considered assessable. Of 65 patients, 41 had glioblastoma, and 24 had anaplastic astrocytoma. Of the 65 assessable patients, 15 (23%) had an objective response (R), and 18 (28%) had stable disease (S), with a combined R and S rate of 51%. The Kaplan-Meier median time to progression was 24 weeks for the responders, 10 weeks for the nonresponders, and 23 weeks for the whole group. These results suggest that Betaseron has definite activity in recurrent gliomas, with an R + S rate of 51%. The maximum-tolerated dose (MTD) is between 180 and 360 x 10(6) IU, with neurotoxicity being the most troublesome toxicity at higher doses. Two patients died of treatment-related complication. Since most responders showed responses at the 180 x 10(6 IU dose range, further studies using a lower dose of Betaseron aimed at decreasing toxicity and allowing chronic maintenance therapy are merited.

Adult↗
PubMed1991

Comparison of chlorambucil and prednisone versus cyclophosphamide, vincristine, and prednisone as initial treatment for chronic lymphocytic leukemia: long-term follow-up of an Eastern Cooperative Oncology Group randomized clinical trial.

The Eastern Cooperative Oncology Group (ECOG) conducted a study in which patients with advanced chronic lymphocytic leukemia (CLL) were randomized between a regimen consisting of chlorambucil (30 mg/m2 orally day 1) and prednisone (80 mg orally days 1 to 5) (C + P) administered every 2 weeks and a more intensive regimen of cyclosphosphamide (300 mg/m2 orally days 1 to 5), vincristine (1.4 mg/m2 intravenously [IV] day 1), and prednisone (100 mg/m2 orally days 1 to 5) (CVP) given every 3 weeks. Treatment was continued for up to 18 months to maximal response. Of the 122 eligible patients, 60 received C + P, while 62 received CVP. With a median follow-up of 7 years, there were no significant differences in survival (4.8 v 3.9 years, P = .12), complete remission (CR) rate (25% v 23%; P = .83), or duration of response (2.0 v 1.9 years; P = .78) between C + P and CVP. Toxicity was modest despite the prolonged treatment. The long median survival of 4.1 years for stage III and IV patients is superior to that usually reported. This could stem from continuing treatment to maximal response rather than an increase in intensity of therapy. These results are comparable to those reported with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) therapy by other investigators. The data suggest that intermittent C + P administered to maximal response continues to be the standard treatment approach for advanced CLL.

Adult↗
PubMed1990

Direct relationship between remission duration in acute myeloid leukemia and cell cycle kinetics: a leukemia intergroup study.

Cell cycle characteristics including labeling indices (LI), duration of S-phase (Ts), and total cell cycle time (Tc) were determined in 54 standard-risk, newly diagnosed patients with acute myeloid leukemia following an infusion of bromodeoxyuridine. Remission induction therapy consisting of cytosine arabinoside and daunomycin was then administered to all patients, followed by three courses of consolidation to those who achieved complete remissions (CR). Older patients appeared to have more rapidly cycling cells (P = .003). No unique cell cycle characteristics were identified for patients who achieved remission versus those who had resistant disease. However, the pretherapy cell cycle characteristics were a strong prognosticator for remission duration. CR patients were divided into those whose leukemic cell Tc were above median (A) and below median (B). Among 14 B patients, median duration of response was 211 days, and all relapsed by day 600. Among 18 A patients, the median has not as yet been reached, with nine patients in continuous complete remission (log rank P = .007, Wilcoxon P = .04). We conclude that cell cycle characteristics of leukemic cells play a role in determining remission duration, perhaps because the leukemic cells of the former patients regrow slowly between courses of chemotherapy.

Bone Marrow↗
PubMed1990

Characterization of a cDNA encoding for the 28.5-kDa LHCII apoprotein from the unicellular marine chlorophyte, Dunaliella tertiolecta.

Three distinct clones, encoding light-harvesting chlorophyll (LHCII) proteins associated with photosystem II were isolated from a cDNA library of the unicellular marine chlorophyte, Dunaliella tertiolecta. We determined the nucleotide sequence of one of these clones, as well as the N-terminal amino acid (aa) sequences of the four mature LHCII apoproteins (24.5, 28.5, 30 and 31 kDa). The sequenced cDNA clone encoded the precursor of the 28.5-kDa apoprotein. We deduced that the transit peptide is 30 aa long and the mature protein is processed between A and V within the peptide RAAVEFYGP. Southern blots of D. tertiolecta genomic DNA indicated the presence of three to five genes. The algal aa sequence differs from higher plants mainly in the transit peptide and the N terminus. Several aa residues, highly conserved in higher plants, which are believed to play a role in chlorophyll binding, are not conserved in the chlorophytes.

Amino Acid Sequence↗
PubMed1990

Isolation and characterization of cDNAs from Lycopersicon esculentum and Arabidopsis thaliana encoding the 33 kDa protein of the photosystem II-associated oxygen-evolving complex.

We have identified and isolated cDNA clones of the 33 kDa protein of the oxygen-evolving complex (OEE1) from Lycopersicon esculentum (tomato) and Arabidopsis thaliana and determined their nucleotide sequences. The cDNA clones and antibodies prepared against OEE1 were used as probes to examine the expression of the oee1 gene with respect to regulation by light, organ specificity, and ripening stage of tomato fruit. The steady-state mRNA level is regulated by light, being present in light-grown plants and absent in etiolated seedlings. The oee1 transcripts that accumulate during growth in the light were reduced to non-detectable or low levels by a 3-day dark treatment. The oee1 gene also exhibits differential expression in various organs of the tomato plant. Steady-state mRNA level was highest in immature leaves and absent in roots while the protein was most abundant in mature leaves and absent in roots. During tomato fruit ripening oee1 mRNA decreases to a low level in the pericarp while the protein level decreases below detection. The expression of oee1 appears to be under the control of a complex mechanism regulating both the amount of RNA and its translation.

Amino Acid Sequence↗
PubMed1990

Detection of HIV-1 in human lung macrophages using the polymerase chain reaction.

We have used the polymerase chain reaction to investigate HIV-1 infection of lung macrophages from 44 AIDS patients with pneumonia. Proviral HIV-1 DNA was detected in the lung macrophages of 47% (21 of 44) of patients tested; 32% (seven of 21) of the patients had Pneumocystis carinii pneumonia (PCP), and 56% (11 of 21) had pneumonia caused by other aetiological agents. Matched peripheral blood specimens were obtained from 22 patients in this study, and HIV-1-specific DNA was detected in 100% (22 out of 22) of non-adherent white cell preparations tested. HIV was detected in blood monocytes of 11 out of 22 patients (50%), and a virus signal was also found in the lung macrophages of eight of these patients. Our results indicate that PCP does not predispose lung macrophages to HIV-1, nor does HIV-1 infection of lung macrophages increase the probability of contracting PCP.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Improved therapeutic index of cisplatin analogue: B-85-0040 by circadian timing.

1. B-85-0040 is a new cisplatin analogue with dose limiting myelosuppression. 2. The maximum tolerated dose ranges between 300 and 525 mg/kg for single i.p. bolus injection in mice. 3. Its toxicity is circadian-stage dependent with optimal tolerance between 16 and 17 hours after lights on. 4. B-85-0040 is active in L1210 leukemia. Anti-tumor activity seems to be unrelated to the circadian stage of treatment. Optimal drug timing can therefore increase its therapeutic index.

Animals↗
PubMed1989

A truncated analog of a pre-light-harvesting chlorophyll a/b protein II transit peptide inhibits protein import into chloroplasts.

It is unclear how transit peptides target nuclear-encoded precursor proteins to the chloroplast. This study establishes the feasibility of using synthetic peptides as competitive inhibitors of chloroplast protein import and as probes for the function of domains within transit peptides. We show that peptide pL(1-20), MAASTMALSSPAFAGKAVNY, an analog of the NH2 terminus of a pre-light harvesting chlorophyll a/b protein II from Arabidopsis, inhibits the import of several Arabidopsis and pea precursor proteins into pea chloroplasts. Inhibition occurs at a step between the initial binding of precursors to the chloroplast and the first proteolytic cleavage event and is not due to interference with ATP availability or chloroplast integrity. Presumably this reflects specific binding of the peptide to the import machinery in the chloroplast envelope. Our data are consistent with the suggestion (Karlin-Neumann, G. A., and Tobin, E. M. (1986) EMBO J. 5, 9-13) that two conserved blocks of amino acids near the NH2-terminus of transit peptides (spanned by peptide pL(1-20] participate in protein targeting. Computer analysis also shows peptide pL(1-20) lacks the amphiphilic properties characteristic of pre-sequences of many nuclear-encoded mitochondrial proteins. This shows a difference in the mechanisms for targeting proteins to chloroplasts and mitochondria.

Amino Acid Sequence↗
PubMed1989

Dominantly transmitted hematologic dysfunction clinically similar to Fanconi's anemia.

We report a family with a dominantly transmitted syndrome resembling Fanconi's anemia and spanning two generations. This syndrome was characterized by an ill-defined hematologic stem cell disorder, immune dysfunction, poor dentition, hyperpigmented skin, warts, and multiple second trimester spontaneous abortions and included one case of acute myelomonocytic leukemia (acute non-lymphocytic leukemia, M4). This family lacks the characteristic chromosomal aberrations of Fanconi's anemia. We believe this constellation of findings represents an entity not previously described.

Abortion, Habitual↗
PubMed1989

Age differences in the acculturation process.

Age differences were assessed in a conceptual model that seeks to explain how acculturation affects psychological well-being among Mexican Americans. The data were from a national probability sample of 859 persons of Mexican decent. It was hypothesized that low acculturation creates financial stress. Moreover, low acculturation and financial stress were in turn predicted to erode feelings of personal control and self-esteem. Finally, diminished feelings of control and low self-esteem were hypothesized to exert a negative impact on psychological well-being. When data from respondents of all ages was assessed, empirical support was found for all of the hypotheses except the linkage between acculturation and financial stress. However, few age differences emerged in the model. The authors conclude that older Mexican Americans may not be more vulnerable to the stressors associated with acculturation.

Acculturation↗
PubMed1989

The prevalence and risk of diabetic retinopathy among Indians of southwest Oklahoma.

The overall prevalence of diabetic retinopathy was 49.3% among 142 diabetic Indians examined at the Indian Health Service at Clinton, Oklahoma. Univariate analysis suggested a positive relationship between duration of diabetes and prevalence of retinopathy. This Indian diabetic population should be examined yearly for diabetic retinopathy.

Adult↗
PubMed1988

Localization of a 64-kDa phosphoprotein in the lumen between the outer and inner envelopes of pea chloroplasts.

The identification and localization of a marker protein for the intermembrane space between the outer and inner chloroplast envelopes is described. This 64-kDa protein is very rapidly labeled by [gamma-32P]ATP at very low (30 nM) ATP concentrations and the phosphoryl group exhibits a high turnover rate. It was possible to establish the presence of the 64-kDa protein in this plastid compartment by using different chloroplast envelope separation and isolation techniques. In addition comparison of labeling kinetics by intact and hypotonically lysed pea chloroplasts support the localization of the 64-kDa protein in the intermembrane space. The 64-kDa protein was present and could be labeled in mixed envelope membranes isolated from hypotonically lysed plastids. Mixed envelope membranes incorporated high amounts of 32P from [gamma-32P]ATP into the 64-kDa protein, whereas separated outer and inner envelope membranes did not show significant phosphorylation of this protein. Water/Triton X-114 phase partitioning demonstrated that the 64-kDa protein is a hydrophilic polypeptide. These findings suggest that the 64-kDa protein is a soluble protein trapped in the space between the inner and outer envelope membranes. After sonication of mixed envelope membranes, the 64-kDa protein was no longer present in the membrane fraction, but could be found in the supernatant after a 110,000 x g centrifugation.

Adenosine Triphosphate↗