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Biomedical subjects

M Greenberg

Publications and source records attributed to M Greenberg.

At least 73 records · Page 4Linked to original sources
PubMed1998

Lack of cisplatin-ranitidine kinetic interactions: in vivo study in children, and in vitro study using dog renal brush border membrane vesicles.

The interactions between cisplatin and organic ions have been extensively investigated in animal models for the potential to reduce cisplatin cellular uptake and resultant nephrotoxicity. To further investigate the beneficial interaction clinically, we studied the effects of the organic cation, ranitidine, on the renal handling of cisplatin in children. In parallel, we examined the effects of cisplatin on the uptake kinetics of organic cations and anions by brush border membrane vesicles (BBMV) prepared from dog renal cortex. The results indicate that: 1) there is no measurable effect of ranitidine on renal clearance of cisplatin in children; and 2) BBMV uptake of anionic p-aminohippurate, but not cationic N-methylnicotinamide, is inhibited by cisplatin at concentrations of <1 mM. These findings suggest that cisplatin may not share transport systems with organic cations to a clinically significant degree. Assuming that renal tubular transport is a prerequisite for cisplatin nephrotoxicity, the lack of apparent kinetic interactions between cisplatin and organic cations may preclude clinical use of organic cations as a modality to prevent cisplatin nephrotoxicity.

Adolescent↗
PubMed1998

The information needs of well, longer-term survivors of breast cancer.

Nine focus groups for well, longer-term survivors of breast cancer were held in Ontario, Canada. Prevalent themes identified through analysis of focus group transcripts fell into two broad categories, one reflecting the context within which women seek information and the other reflecting the content of information desired and sought. Themes related to context included: the ongoing impact on women of their initial disease experience and continued uncertainty about possible recurrence; womens' lack of information and understanding about processes involved in developing medical knowledge; prevailing mistrust about the impact of cost curtailment policies; and, concerns related to how professional communication can aid or hinder the goal of obtaining information. Themes related to content issues included: follow-up protocols, tamoxifen, detecting signs of possible recurrence, prevention for daughters, neglected side effects of treatment, insurance, lifestyle, and unconventional therapies.

Adult↗
PubMed1998

A strategy for informing patients and health professionals about unconventional cancer therapies.

BACKGROUND: A Guide to Unconventional Cancer Therapies was produced by the Ontario Breast Cancer Information Exchange Project with the intention of meeting needs of patients, family members, and health professionals for information about unconventional therapies. Concerns raised by health professionals during the development of the guide serve as a focus for considering its impact on cancer patients who purchased it. MATERIALS AND METHODS: Purchasers of the guide were sent a survey questionnaire inquiring about their access to, use of, and attitudes toward it. RESULTS: A total of 634 individuals responded to the survey, including cancer patients, health professionals, and family members. The guide was rated moderately helpful overall, and health professionals found it significantly more helpful than did cancer patients. A minority of patients were influenced to try an unconventional therapy as a result of reading the guide. Those who did try a new therapy typically chose ones that are most popular and have few potential negative effects. CONCLUSIONS: As an informational strategy, the Guide to Unconventional Cancer Therapies has been successful. Concerns expressed by some health professionals about potential harm through implementing the strategy have been shown to be largely unwarranted, at least for study respondents.

Breast Neoplasms↗
PubMed1998

A survey of New Jersey industrial hygienists and safety engineers: health and safety conditions, practices, and priorities for OSHA reform.

This study reports the results of an analysis of responses from more than 400 New Jersey industrial hygienists and safety engineers to a survey examining a wide range of health and safety conditions and practices. Findings are reported on a number of variables including the types and seriousness of safety and health hazards encountered at the respondents' work sites, perceived improvements in health and safety conditions, compliance with right-to-know requirements, the effectiveness of resources used in correcting hazards, and the barriers encountered in addressing hazardous conditions. The respondents were also asked to rank their priorities regarding 14 proposals for Occupational Safety and Health Administration (OSHA) reform. Opinion questions were scaled to reflect the respondent's sense of the importance of each variable. One finding of particular interest is that worker involvement in health and safety committees was perceived as an "effective" or "very effective" resource by more than one-half of the respondents. Changes in the Occupational Safety and Health Act that would strengthen requirements for worker participation were among the respondents' top priorities for OSHA reform.

Attitude of Health Personnel↗
PubMed1998

Transmission of Chlamydia trachomatis and Neisseria gonorrhoeae among men with urethritis and their female sex partners.

Transmission of Chlamydia trachomatis and Neisseria gonorrhoeae among infected men and their female sex partners was examined using a design enhancing the likelihood that spread was directed from men to women. Chlamydia culture-negative specimens were examined using DNA amplification tests. Infection rates in women exposed to male sex partners with Chlamydia only were 65% (20/31) and with gonorrhea only were 73% (33/45). Infection of women by either agent was not influenced by the number of sexual exposures to or coinfection in men. There was a 98% (40/41) concordance of N. gonorrhoeae isolates among partners by auxotype and serovar. Chlamydia isolates were serotyped using ELISA and immunofluorescence testing and confirmed by nested polymerase chain reaction: 50% (6/12) of men and 57% (8/14) of women yielded mixed serovars. Sixty-four percent of pairs (9/14) were infected with identical serovars and an additional 28% shared at least one serovar. Multiple serovars of C. trachomatis, but not of N. gonorrhoeae, were common in sex partners and exchanged frequently.

Boston↗
PubMed1998

Exploring the barriers to cervical screening in an urban Canadian setting.

Cervical cancer is potentially one of the most preventable cancers. The benefits of cervical screening come to those who are actually screened. Despite the known value of cervical screening, a significant number of women do not avail themselves of the procedure. This study examined the barriers to cervical screening in an urban Canadian setting. Focus group methodology was used to explore the perspectives of socioeconomically disadvantaged women regarding their access to health care. The sessions were tape-recorded, and subsequent content analysis revealed four broad themes: being able to talk with doctors is important; being treated as a person is important; finding answers to many questions about cancer is important; and having a Pap test is uncomfortable. Implications for practice and program design were highlighted.

Adult↗
PubMed1998

Outcome analysis of rhabdomyosarcoma of the lower urinary tract.

PURPOSE: Multimodal therapy has resulted in a high cure rate for genitourinary rhabdomyosarcoma. We propose that the strategy of induction chemotherapy followed by excision and reconstruction without radiotherapy may provide a high cure rate without the late sequelae of pelvic radiotherapy. MATERIALS AND METHODS: We reviewed the records of 13 patients with a mean age of 3.3 years diagnosed with rhabdomyosarcoma of the urinary tract from 1986 to 1996. The primary site was the bladder in 4 cases and prostate in 9. After biopsy confirmation of the diagnosis patients were treated with chemotherapy and subsequent surgery, while radiotherapy was reserved for those with residual disease. RESULTS: After induction chemotherapy 8 patients underwent tumor excision via an organ sparing approach, which involved radical prostatectomy and partial cystectomy with or without bladder augmentation. In 5 patients the final pathological analysis showed positive margins. Repeat surgery in 6 patients included complete cystectomy and urinary diversion in 2 who had positive margins and recurrence after radiotherapy, urethrectomy and continent diversion for positive margins in 1, partial cystectomy and continent diversion in 1, and radical prostatectomy, partial cystectomy and continent diversion in 1 with stage IV disease who had local recurrence. In the latter case ileocystoplasty had been performed for a small noncompliant bladder. Six patients with microscopic residual or metastatic disease received radiotherapy. At a mean followup of 5.6 years 11 patients are disease-free. Continence was preserved in all reconstructed cases. Erections were reported in 8 patients, and renal function was maintained in 10. CONCLUSIONS: Our results suggest that urinary tract reconstruction may be safely performed at primary excision surgery, radiotherapy induced morbidity may be minimized by limiting radiotherapy to residual and metastatic disease, frozen section results may be false-negative, potency may be achieved and radiological disappearance of the tumor should be confirmed histologically.

Child↗
PubMed1998

A conceptual design for cosmo-biology experiments in Earth's Orbit.

A conceptual design was developed for a cosmo-biology experiment. It is intended to expose simulated interstellar ice materials deposited on dust grains to the space environment. The experimental system consists of a cryogenic system to keep solidified gas sample, and an optical device to select and amplify the ultraviolet part of the solar light for irradiation. By this approach, the long lasting chemical evolution of icy species could be examined in a much shorter time of exposure by amplification of light intensity. The removal of light at longer wavelength, which is ineffective to induce photochemical reactions, reduces the heat load to the cryogenic system that holds solidified reactants including CO as a constituent species of interstellar materials. Other major hardware components were also defined in order to achieve the scientific objectives of this experiment. Those are a cold trap maintained at liquid nitrogen temperature to prevent the contamination of the sample during the exposure, a mechanism to exchange multiple samples, and a system to perform bake-out of the sample exposure chamber. This experiment system is proposed as a candidate payload implemented on the exposed facility of Japanese Experiment Module on International Space Station.

Cold Temperature↗
PubMed1998

Information needs of women with metastatic breast cancer.

Eight focus groups involving women with metastatic breast cancer were held across Ontario over approximately 6 months in 1996-97. Prevalent themes identified during the sessions are reported under 2 broad dimensions: the women's expressed desire for information in specific content areas, and issues related to whether information can be either beneficial or harmful, depending on how it is provided. The women reported high needs for information, especially that which would relate to their situation. Perceived adequacy of information is closely linked to health professional engagement and care. Although the provision of information is important, the needs of these women for maintenance of hope and provision of interpersonal support and comfort are also critical.

Adult↗
PubMed1998

Factors which support effective worker participation in health and safety: a survey of New Jersey industrial hygienists and safety engineers.

Strategies for increasing worker involvement in health and safety are widespread and have received emphasis in various OSHA reform proposals; however, much remains unknown about the effectiveness of these strategies. This paper draws on a survey of more than 400 New Jersey members of the American Industrial Hygiene Association (AIHA) and the American Society of Safety Engineers (ASSE) which addressed a broad range of issues relating to health and safety conditions and practices, including the use of worker or labor/management health and safety committees (HSCs) and worker health and safety representatives. Stepwise discriminant analysis was used to explore the relationships between effective participation and variables which describe worksites and potential health and safety resources and barriers. Effective strategies for involving workers appear to be conditional on a number of variables, most importantly on worker activism and the effective use of formal union negotiations. Findings are consistent with studies from both the U.S. and abroad which emphasize the role of unions in shaping opportunities for effective worker participation.

Community Participation↗
PubMed1998

Self-help groups.

OBJECTIVE: To assess Ontario family physicians' attitudes toward, awareness of, and practices related to self-help groups in general and cancer self-help groups specifically. DESIGN: Mailed survey using a modified Dillman method. SETTING: Ontario family practices. PARTICIPANTS: A random sample of 1500 Ontario members of the College of Family Physicians of Canada, of whom 949 responded. A total of 911 completed questionnaires were received, for an eligible response rate of 64%. MAIN OUTCOME MEASURES: Physician demographics, practice characteristics; extent of awareness of self-help groups and their perceived value; attitudes toward self-help groups; practices related to interactions with patients about self-help groups. RESULTS: Only 40.2% of respondents were aware of six or more self-help groups in their region; 56.8% were aware of at least one cancer self-help group. Discussions with patients about groups were reported as occurring "frequently" by 12% of respondents, who indicated they made referrals to an array of groups. Ratings of group helpfulness were relatively high (83.8% scoring 3, 4, or 5 on a 5-point scale, where 5 is "very helpful"). There were low ratings of potential harm (1% scoring 4 or 5 on a 5-point scale, where 5 is "very harmful"). Confidence intervals for proportions reported on in this paper were all within 4%. CONCLUSIONS: Family physicians have predominantly positive attitudes about the potential benefits of self-help groups, and many are recommending groups to their patients.

Female↗
PubMed1997

Autonomic response to change of posture among normal and mild-hypertensive adults: investigation by time-dependent spectral analysis.

In this study, we applied the time-dependent spectral analysis approach (SDA) to investigate the autonomic changes occurring during a transition from supine to standing position (CP), in normal and unmedicated mild hypertensive subjects. The SDA method enables an accurate follow-up of the instantaneous changes in autonomic activity, even during the unsteady phase of the transition, where sudden changes in heart rate (HR) and arterial blood pressure (ABP) are observed. We were able to quantify the vagal withdrawal (reflected in the high frequency component of the time-dependent spectrum of HR fluctuations) in the immediate response to CP and the more slowly following sympathetic increase (reflected in the low frequency component of ABP). This general pattern was observed in both groups. In addition, our results identified an altered sympathetic response to CP in mild-hypertensives, as compared to normal adults. Their basal sympathetic activity is enhanced (higher mean HR and increased low frequency fluctuations in ABP) and their response to CP is reduced, as reflected only in the LF content of ABP fluctuations, relative to normals. No difference was observed in HR fluctuations, showing that there is no parasympathetically mediated alteration of the baroreflex control of HR in mild-hypertension.

Adult↗
PubMed1997

Cervical specimens collected in liquid buffer are suitable for both cytologic screening and ancillary human papillomavirus testing.

BACKGROUND: Several new techniques have been developed to improve the sensitivity of cervical carcinoma screening and reduce equivocal cytologic diagnoses referred to as atypical squamous cells of undetermined significance (ASCUS). This study evaluates the effectiveness of combining two newly introduced diagnostic techniques: preparation of thin-layer cytologic slides from ThinPrep liquid buffer and selected Hybrid Capture testing for human papillomavirus (HPV) DNA. Because HPV DNA detection has been strongly associated with the presence of a cervical carcinoma precursor ("squamous intraepithelial lesion," or SIL), HPV testing might be useful for identifying women with ASCUS who have an underlying SIL. METHODS: Two hundred specimens demonstrating diverse cervical abnormalities were selected from a prospective population-based study of 9174 women conducted in Costa Rica. The entire cohort had been screened with conventional cervical smears; ThinPrep slides made from liquid buffer, PAPNET, a computerized slide reading system; and Cervicography. Patients with any abnormal screening test were referred for colposcopy, punch biopsy, and loop excision of cases with high grade cytologic abnormalities not explained by punch biopsy. For this investigation, the results of ThinPrep cytology and HPV testing alone and in combination were compared with the final diagnoses, with an emphasis on the detection of carcinoma and high grade SIL. RESULTS: The 200 subjects studied included 7 women with a final diagnosis of carcinoma, 44 with high grade SIL, 34 with low grade SIL, 51 with a variety of equivocal diagnoses, and 64 with normal diagnoses. A ThinPrep cytologic diagnosis of SIL or carcinoma was made in 39 (76%) of the 51 women with final diagnoses of high grade SIL or carcinoma. Hybrid Capture testing detected carcinoma-associated types of HPV DNA in 100% of women with carcinoma, 75% with high grade SIL, 62% with low grade SIL, 20% with equivocal final diagnoses, and 12% of normal women. If colposcopy referral had been limited to women with a ThinPrep diagnosis of SIL or a diagnosis of ASCUS associated with the detection of carcinoma-associated HPV DNA from the same vial, 100% of women with carcinoma and 80% with high grade SIL would have been examined. To achieve this high sensitivity in the entire population of 9174 women would have required the referral of about 7% of the population. The combined screening strategy would have performed marginally better than optimized conventional screening with referral of any abnormal cytology (ASCUS and above). CONCLUSIONS: A cervical carcinoma screening technique which uses a single sample for cytopathology and HPV testing to triage equivocal diagnoses may be promising if it proves to be cost-effective.

Carcinoma↗
PubMed1997

A battle for compensation for Welsh coal miners: JS Haldane v "Sericite" Jones, 1932-1934.

Toward the end of the 1920s, technical advances in mining led to an increase in airborne burdens of dust in the South Wales coal mines. This coincided with a dramatic increase in the incidence of disability and death from respiratory disease among the miners. For their condition to be compensable, claimants were required to have worked with rock containing more than 50% 'free silica.' Dr W.R. Jones, a mining geologist, was asked to help obtain compensation for those claimants who could not satisfy the 'free silica' condition. He was unable to identify high-silica rocks where none had been said to exist. He did however, successfully argue the brief against the eminent Professor J.S. Haldane (who was the dominant authority, having had lengthy experience in the field of health and mining), for the fibrous form of sericite being commonly the important agent responsible for pneumoconiosis. As a consequence, the category of miner eligible for compensation was broadened. Evidence was gathered worldwide that supported the hypothesis that silicates and not just crystalline silica could cause pneumoconiosis. Despite the suspicions raised about the special power of mineral fibers during this public debate, some 40 years were to elapse before potential health hazards from fibers other than asbestos were to be taken seriously and investigated.

Coal↗