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Biomedical subjects

M Ross

Publications and source records attributed to M Ross.

At least 37 records · Page 2Linked to original sources
PubMed2001

From chump to champ: people's appraisals of their earlier and present selves.

The authors present and test a theory of temporal self-appraisal. According to the theory, people can maintain their typically favorable self-regard by disparaging their distant and complimenting their recent past selves. This pattern of appraisals should be stronger for more important attributes because of their greater impact on self-regard and stronger for self-ratings than for ratings of other people. Studies 1 and 2 demonstrated that participants are more critical of distant past selves than of current selves, and Study 3 showed that this effect is obtained even when concurrent evaluations indicate no actual improvement. Studies 4 and 5 revealed that people perceived greater improvement for self than for acquaintances and siblings over the same time period. Study 6 provided support for the predicted effects of temporal distance and attribute importance on people's evaluation of past selves.

Adult↗
PubMed2001

Smoking amongst UK Bangladeshi adolescents aged 14-15.

This paper reports on an investigation into smoking amongst 14- to 15-year-old Bangladeshis living in an UK inner city locality. A survey using self-completion questionnaires was undertaken in conjunction with focus group discussions. The survey of 316 Bangladeshi adolescents was conducted to determine smoking prevalence. Regular smoking was more common amongst Bangladeshi males (39%) than amongst Bangladeshi females (11%). Thirty-one people (17 females and 14 males) took part in seven focus groups (four female and three male) which were conducted in schools (six) and youth clubs (one). Focus group discussions were conducted to examine what smoking means to Bangladeshi teenagers and factors which influence why they do or do not smoke. Differences between what smoking means to Bangladeshi females and males are identified which arise from perceived social norms and cultural values, and greatly influence smoking uptake. However, many of the reasons why Bangladeshi adolescents continue to smoke, stop smoking or never smoke appear similar to those identified in other studies with largely white adolescents. Factors underpinning adolescent choices together with the implications of the study findings for the development of smoking prevention initiatives for inner city Bangladeshi teenagers are discussed.

Adolescent↗
PubMed2001

Phase II evaluation of bryostatin-1 in metastatic melanoma.

In this phase II study we assessed the efficacy of bryostatin-1 (NSC 339555) in metastatic melanoma patients when given intravenously either once a week at a dose of 25 microg/m2 per day over 24 h for 3 weeks or at 40 microg/m2 per day over 72 h every 2 weeks. Treatment courses were repeated every 4 weeks. Patients who had received one prior chemotherapy regimen for advanced melanoma, with or without biotherapy, were randomized to one or the other bryostatin-1 dose schedules until 12 patients were registered to each arm. Because there was one confirmed response among the 12 patients who received the 72 h dose schedule, 25 more patients were added to that arm. No prophylactic medications were given. Objective tumour measurements were used to assess the efficacy of the regimen. The National Cancer Institutes common toxicity criteria were used to grade reactions. In total, 49 patients with metastatic melanoma, none having symptomatic brain metastasis, were studied. Of these, 12 patients received the 24 h bryostatin-1 regimen, while the remaining 37 received the 72 h regimen. One patient receiving the 72 h regimen had a partial response lasting over 7 months. Muscle pain occurred in over 90% of the patients and was the dose-limiting side effect of the 72 h regimen. Grade 3/4 nausea and vomiting were more common on the 24 h regimen than on the 72 h one (35% versus 5% of patients). There was no therapy-related thrombocytopenia. Neutropenia was mild and mainly limited to patients receiving the 72 h regimen. Bryostatin-1 has limited activity against melanoma when given by 72 h intravenous infusion.

Adolescent↗
PubMed2001

Acceptance of syphilis screening among residents of high-STD-risk Houston communities.

The purpose of this study was to assess the rate of acceptance of street-intercept syphilis screening and to identify barriers to screening among residents of 2 Houston communities with high rates of syphilis. Each of 691 people who participated in a street-intercept survey about syphilis was offered a free syphilis test immediately after completion of the survey. Acceptors of screening had blood drawn at the site of the interview, and blood samples were tested by rapid plasma reagin (RPR) and a confirmatory microhaemagglutination-Treponema pallidum (MHA-TP) for those with a positive antibody reaction on the RPR. On-street syphilis screening was accepted by 26% of the sample. The most common reason for refusal was not wanting to have blood drawn (19.5%). Among those screened for syphilis (n=148), seroprevalence was 19%, with 33% of women testing positive and 10% of men. The results of this study point to a need for increased case-finding, standard screening recommendations, and interventions targeting specific barriers to syphilis screening.

Adult↗
PubMed2001

Wireless telephones and hearing aids: an overview.

Wireless telephones are becoming increasingly common and will be more so in the future. Unfortunately, many are unusable with hearing aids and may actively interfere with the normal use of hearing aids because of the electromagnetic interference (EMI) generated by wireless telephones. The EMI generated by digital wireless telephones is much greater than that of analog wireless telephones. More research and design work needs to be done before wireless telephones can be considered accessible to people who use hearing aids.

Hearing Aids↗
PubMed2001

Trust and communicated attributions in close relationships.

The attributional statements intimate partners communicate to one another were examined as a function of trust. In discussions by 35 married couples, 850 attributions and corresponding events were coded on dimensions of valence, globality, and locus. Results of regression and contingency analyses indicate that attributional statements expressed in high-trust relationships emphasized positive aspects of the relationship. Medium-trust couples actively engaged issues but focused more on negative events and explanations. Low-trust couples expressed more specific, less affectively extreme attributional statements that minimized the potential for increased conflict. Results could not be accounted for by relationship satisfaction. These findings also highlight the importance of focusing on features of the events for which attributions are expressed.

Adult↗
PubMed2000

Melting of the rare earth metals and f-electron delocalization

Melting curves for Pr, Nd, Sm, Gd, and Y were measured in a diamond-anvil-cell to nearly 100 GPa and 4000 K. f-electron volume collapses are observed as triple points for Pr (24 GPa and 1400 K) and Gd (65 GPa and 3100 K). These pressures coincide with the volume collapses observed at room temperature. For Nd and Sm, the f-electron volume collapse has not been observed at room temperature but appears at approximately 2000-2500 K as a broad minimum in the melting curve, similar to that of Ce, near 50 GPa (Nd) and 70 GPa (Sm). The melting curve of Y goes smoothly along the entire rare earth sequence.

Journal Article↗
PubMed2000

Aetiology, outcome, and risk factors for mortality among adults with acute pneumonia in Kenya.

BACKGROUND: Despite a substantial disease burden, there is little descriptive epidemiology of acute pneumonia in sub-Saharan Africa. We did this study to define the aetiology of acute pneumonia, to estimate mortality at convalescence, and to analyse mortality risk-factors. METHODS: We studied 281 Kenyan adults who presented to two public hospitals (one urban and one rural) with acute radiologically confirmed pneumonia during 1994-96. We did blood and lung-aspirate cultures, mycobacterial cultures, serotype-specific pneumococcal antigen detection, and serology for viral and atypical agents. FINDINGS: Aetiology was defined in 182 (65%) patients. Streptococcus pneumoniae was the most common causative agent, being found in 129 (46%) cases; Mycobacterium tuberculosis was found in 26 (9%). Of 255 patients followed up for at least 3 weeks, 25 (10%) died at a median age of 33 years. In multivariate analyses, risk or protective factors for mortality were age (odds ratio 1.51 per decade [95% CI 1.04-2.19]), unemployment (4.42 [1.21-16.1]), visiting a traditional healer (5.26 [1.67-16.5]), visiting a pharmacy (0.30 [0.10-0.91]), heart rate (1.64 per 10 beats [1.24-2.16]), and herpes labialis (15.4 [2.22-107]). HIV-1 seropositivity, found in 52%, was not associated with mortality. Death or failure to recover after 3 weeks was more common in patients with pneumococci of intermediate resistance to benzylpenicillin, which comprised 28% of pneumococcal isolates, than in those infected with susceptible pneumococci (5.60 [1.33-23.6]). INTERPRETATION: We suggest that tuberculosis is a sufficiently common cause of acute pneumonia in Kenyan adults to justify routine sputum culture, and that treatment with benzylpenicillin remains appropriate for clinical failure due to M. tuberculosis, intermediate-resistant pneumococci, and other bacterial pathogens. However, interventions restricted to hospital management will fail to decrease mortality associated with socioeconomic, educational, and behavioural factors.

Acute Disease↗
PubMed2000

Development of a new in vitro model for the study of benign prostatic hyperplasia.

BACKGROUND: The search for novel agents for the treatment of the lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) is dependent on an increased understanding of the pathophysiology of the disease. Unfortunately, in vitro and animal models have been of limited value. METHODS: This article describes a novel model system in which the interactions of the stromal and epithelial components of the prostate gland can be determined. RESULTS: The coculture system provides a simple model of the cellular interactions occurring in the adult human prostate. CONCLUSIONS: This coculture system could potentially be used to determine the precise molecular site of action of agents such as terazosin on prostatic apoptosis.

Cell Differentiation↗
PubMed2000

Analysis of lung surfactant model systems with time-of-flight secondary ion mass spectrometry.

An often-used model lung surfactant containing dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG), and the surfactant protein C (SP-C) was analyzed as Langmuir-Blodgett film by spatially resolved time-of-flight secondary ion mass spectrometry (TOF-SIMS) to directly visualize the formation and composition of domains. Binary lipid and lipid/SP-C systems were probed for comparison. TOF-SIMS spectra revealed positive secondary ions (SI) characteristic for DPPC and SP-C, but not for DPPG. SI mapping results in images with domain structures in DPPC/DPPG and DPPG/SP-C, but not in DPPC/SP-C films. We are able to distinguish between the fluid and condensed areas probably due to a matrix effect. These findings correspond with other imaging techniques, fluorescence light microscopy (FLM), scanning force microscopy (SFM), and silver decoration. The ternary mixture DPPC/DPPG/SP-C transferred from the collapse region exhibited SP-C-rich domains surrounding pure lipid areas. The results obtained are in full accordance with our earlier SFM picture of layered protrusions that serve as a compressed reservoir for surfactant material during expansion. Our study demonstrates once more that SP-C plays a unique role in the respiration process.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2000

Formation of three-dimensional protein-lipid aggregates in monolayer films induced by surfactant protein B.

This study focuses on the structural organization of surfactant protein B (SP-B) containing lipid monolayers. The artificial system is composed of the saturated phospholipids dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG) in a molar ratio of 4:1 with 0.2 mol% SP-B. The different "squeeze-out" structures of SP-B were visualized by scanning probe microscopy and compared with structures formed by SP-C. Particularly, the morphology and material properties of mixed monolayers containing 0.2 mol% SP-B in a wide pressure range of 10 to 54 mN/m were investigated revealing that filamentous domain boundaries occur at intermediate surface pressure (15-30 mN/m), while disc-like protrusions prevail at elevated pressure (50-54 mN/m). In contrast, SP-C containing lipid monolayers exhibit large flat protrusions composed of stacked bilayers in the plateau region (app. 52 mN/m) of the pressure-area isotherm. By using different scanning probe techniques (lateral force microscopy, force modulation, phase imaging) it was shown that SP-B is dissolved in the liquid expanded rather than in the liquid condensed phase of the monolayer. Although artificial, the investigation of this system contributes to further understanding of the function of lung surfactant in the alveolus.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2000

The frequency of temporal-self and social comparisons in people's personal appraisals.

Although past literature emphasizes the importance of social comparisons, in this study it was predicted that participants would often mention temporal comparisons in their self-descriptions. The first 3 studies revealed that participants report as many or more temporal-past comparisons than social comparisons. It was predicted that people would particularly favor temporal-past comparisons when they are interested in enhancing themselves. Temporal-past comparisons are gratifying, because they tend to indicate improvement over time. Social comparisons may be preferred when people are motivated to evaluate themselves accurately. These predictions were supported when self-evaluation and self-enhancement goals were explicitly manipulated (Study 4) or primed (Study 5).

Female↗
PubMed2000

People focus on optimistic scenarios and disregard pessimistic scenarios while predicting task completion times.

Task completion plans normally resemble best-case scenarios and yield overly optimistic predictions of completion times. The authors induced participants to generate more pessimistic scenarios and examined completion predictions. Participants described a pessimistic scenario of task completion either alone or with an optimistic scenario. Pessimistic scenarios did not affect predictions or accuracy and were consistently rated less plausible than optimistic scenarios (Experiments 1-3). Experiment 4 independently manipulated scenario plausibility and optimism. Plausibility moderated the impact of optimistic, but not pessimistic, scenarios. Experiment 5 supported a motivational explanation of the tendency to disregard pessimistic scenarios regardless of their plausibility. People took pessimistic scenarios into account when predicting someone else's completion times. The authors conclude that pessimistic-scenario generation may not be an effective debiasing technique for personal predictions.

Affect↗
PubMed2000

The selectivity and specificity of the actions of the lipido-sterolic extract of Serenoa repens (Permixon) on the prostate.

PURPOSE: To investigate the effects of the phytotherapeutic agent, Permixon(R), on primary cultures of fibroblast and epithelial cells from the prostate, epididymis, testes, kidney, skin and breast and to determine the selectivity and specificity of the action of the drug. MATERIALS AND METHODS: All primary cultures were examined by electron microscopy before and following treatment with Permixon(R) (10 microg./ml.). In addition the apoptotic index was assessed by flow cytometry employing propidium iodide as a fluorophore. The impact of the drug on 5alpha-reductase (5alphaR) isoenzymes was also tested utilizing a pH specific assay. RESULTS: There were changes in the morphology of prostate cells after treatment including accumulation of lipid in the cytoplasm and damage to the nuclear and mitochondrial membranes; no similar changes were observed in other cells. Permixon(R) increased the apoptotic index for prostate epithelial cells by 35% and 12% in the prostate stromal/fibroblast. A lesser apoptotic effect was demonstrated in skin fibroblast (3%) whereas none of the other primary cultures showed any increase in apoptosis when compared with the controls. Permixon(R) was also an effective inhibitor of both 5alphaR type I and II isoenzymes in prostate cells, but other cells showed no inhibition of 5alphaR activity following treatment with the plant extract. CONCLUSIONS: This investigation demonstrated the selectivity of the action of Permixon(R) for prostate cells. The morphological changes in the prostate are accompanied by an increase in the apoptotic index along with an inhibition in the activity of the nuclear membrane bound 5alphaR isoenzymes. No similar changes were observed in any of the other cells under investigation.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2000

Perceived compliance with AZT dosing among a sample of African-American drug users.

The purpose of this report was to present findings from a pilot study conducted to explore the associations between sociodemographic, drug use, and health belief factors and perceived compliance with zidovudine (AZT) among African-American drug users. Data were collected in Washington, DC, USA from individuals who were African-American; were recent or current drug injectors or crack smokers; were HIV-seropositive, and were receiving treatment for HIV infection. Participants were recruited through local organizations that provide services to HIV-infected persons. Participants were interviewed using a questionnaire that solicited sociodemographic, lifetime and current drug use, current sexual behaviours, health status, HIV and drug treatment history, and health belief data. Analyses were limited to individuals currently using an illicit substance and who had received AZT during their medical treatment. Parametric (Pearson's r) and nonparametric (Spearman's rho) statistics were used to assess correlations between perceived compliance with AZT dosing and independent variables. As the study was intended to be both descriptive and exploratory, the level of statistical significance was set at 0.10, rather than the customary 0.05. Antiretroviral medications recognized and recalled by participants are presented. The most commonly recalled medication was AZT. Slightly less than one-third of participants reported being completely compliant with an AZT regimen. Perceived compliance was found to be negatively associated with 5 variables: age, homelessness, number of injections in the previous 30 days, trading sex for drugs, and the perception that AIDS is no longer a serious disease since the development of new antiretroviral medications. Intensity of feelings of joy, fear, and the belief that taking more anti-HIV medications would result in better health were found to be positively correlated. Bivariate associations between perceived compliance and sociodemographic, drug use, sexual behaviour, and health belief variables suggest further avenues of study and potential points for intervention to increase compliance with antiretroviral medications among racial/ethnic minority drug users receiving treatment for HIV infection.

Adolescent↗
PubMed2000

Challenges and directions for Medicare ESRD payment policy.

Since the inception of the ESRD program in 1973, Medicare has been challenged to provide access to high-quality care to beneficiaries with ESRD while trying to contain program payments. Despite implementing policies to control the growth in spending for outpatient dialysis and shifting the risk of certain ESRD beneficiaries to private payers, annual ESRD program payments have grown faster than overall Medicare spending. Some stakeholders contend that these policies have adversely affected beneficiaries' access to high-quality care. Refining the payment systems for caring for beneficiaries with ESRD in traditional Medicare and managed care plans may provide some respite to the growth in ESRD program spending in the short-term. In the long run, ESRD program spending may not be effectively controlled until changes are made in the delivery of health care services to this population.

Humans↗
PubMed1999

Serenoa repens (Permixon): a 5alpha-reductase types I and II inhibitor-new evidence in a coculture model of BPH.

BACKGROUND: The aim of this study was to determine the effect of the phytotherapeutic agent, Permixon, on a novel coculture model of benign prostatic hyperplasia (BPH) in an effort to better understand the mode of action of the drug in vivo. METHODS: The effect of Permixon, at the calculated therapeutic concentration, on the activity of 5alpha-reductase isoenzymes was evaluated utilizing a pH-specific assay. Prostate-specific antigen (PSA) secretions into the medium were measured in the presence and absence of Permixon and quantified by an ELISA assay. The morphological patterns before and following Permixon treatment were also examined by electron microscopy. All results were compared to controls. RESULTS: Permixon at a concentration of 10 micrograms/ml (calculated plasma concentration in patient receiving recommended therapeutic dosage) was shown to be an effective inhibitor of both 5alpha-reductase types I and II isoenzymes without influencing the secretion of PSA by the epithelial cells, even after stimulation with testosterone. The morphology of Permixon-treated cells was found to be markedly different from that of untreated controls. Cells which had been treated with the drug demonstrated extensive accumulation of lipids in the cytoplasm and widespread damage of intracellular membranes, including mitochondrial and nuclear membranes. CONCLUSIONS: Permixon is an effective dual inhibitor of 5alpha-reductase isoenzyme activities in the prostate. Unlike other 5alpha-reductase inhibitors, Permixon induces this effect without interfering with the cells' capacity to secrete PSA, thus permitting the continued use of PSA measurements for prostate cancer screening.

5-alpha Reductase Inhibitors↗