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Biomedical subjects

M S Weinberg

Publications and source records attributed to M S Weinberg.

At least 19 recordsLinked to original sources
PubMed2006

Activation of multiple molecular mechanisms for apoptosis in human malignant glioblastoma T98G and U87MG cells treated with sulforaphane.

Glioblastoma is the most malignant and prevalent brain tumor that still remains incurable. Recent studies reported anti-cancer effect of the broccoli-derived compound sulforaphane. We explored the mechanisms of sulforaphane-mediated apoptosis in human glioblastoma T98G and U87MG cells. Wright staining and ApopTag assay confirmed apoptosis in glioblastoma cells treated with sulforaphane. Increase in intracellular free Ca2+ was detected by fura-2 assay, suggesting activation of Ca2+-dependent pathways for apoptosis. Western blotting was used to detect changes in expression of Bax and Bcl-2 proteins resulting in increased Bax:Bcl-2 ratio that indicated a commitment of glioblastoma cells to apoptosis. Upregulation of calpain, a Ca2+-dependent cysteine protease, activated caspase-12 that in turn caused activation of caspase-9. With the increased Bax:Bcl-2 ratio, cytochrome c was released from mitochondria to cytosol for sequential activation of caspase-9 and caspase-3. Increased calpain and caspase-3 activities generated 145 kD spectrin breakdown product and 120 kD spectrin breakdown product, respectively. Activation of caspase-3 also cleaved the inhibitor-of-caspase-activated-DNase. Accumulation of apoptosis-inducing-factor in cytosol suggested caspase-independent pathway of apoptosis as well. Two of the inhibitor-of-apoptosis proteins were downregulated because of an increase in 'second mitochondrial activator of caspases/Direct inhibitor-of-apoptosis protein binding protein with low pI.' Decrease in nuclear factor kappa B and increase in inhibitor of nuclear factor kappa B alpha expression favored the process of apoptosis. Collectively, our results indicated activation of multiple molecular mechanisms for apoptosis in glioblastoma cells following treatment with sulforaphane.

Analysis of Variance↗
PubMed2001

Preventing transmission of hepatitis B virus from people with chronic infection.

BACKGROUND: People with chronic hepatitis B virus (HBV) infection are the major source of HBV transmission in the United States. The Public Health Service recommends prevention counseling for HBV-infected people and vaccination of their household contacts and sexual partners. OBJECTIVES: To describe the implementation of these recommendations by community physicians. METHODS: Telephone survey of 69 people with chronic HBV infection and their healthcare providers, October 1997 through November 1997, in San Diego, California. MAIN OUTCOME MEASURES: Counseling of people with chronic HBV infection and vaccination of their household contacts and sexual partners. RESULTS: Forty-three percent of providers reported providing prevention counseling to their HBV-infected patients to reduce transmission; 16% of patients reported receiving counseling. For the 32 pairs for which both the patient and provider could be reached and the patients were aware of their HBV infection, 20 (63%) providers reported counseling patients, and 10 (50%) of these providers' patients reported receiving counseling. Fifty-five percent of providers recommended vaccination of contacts; 13% of eligible adult household contacts and sexual partners and 20% of eligible child household contacts had begun hepatitis B vaccination. CONCLUSIONS: Prevention counseling of people with chronic HBV infection and vaccination of their contacts occur infrequently despite guidelines and an effective vaccine. Collaborative efforts between providers and people involved in public health are needed to improve delivery of these preventive health services.

Adolescent↗
PubMed2001

Men sex workers and other men who have sex with men: how do their HIV risks compare in New Zealand?

Sex workers have their perspective on HIV transmission, claiming that in general they are more similar than different from other people in HIV status and the practice of safe sex. Such an assertion of similarity goes against public and professional opinion that prostitution is a major vector in the spread of AIDS. Taking the sex workers' similarity claim seriously, this paper considers the conditions under which it would be valid. We focus on those factors that make a population more or less vulnerable to HIV and how they affect its spread into the sex work population. Data from New Zealand comparing men sex workers and other men who have sex with men is used to evaluate these ideas. Data partially support the hypothesis in that these two groups of men are similar with regard to their HIV status. We do find the sex workers to be different, however, in their being less likely to engage in safe sex practices. We provide an explanation for why this has not lead to their having a higher rate of seropositivity.

Adult↗
PubMed2001

Balance prosthesis based on micromechanical sensors using vibrotactile feedback of tilt.

A prototype balance prosthesis has been made using miniature, high-performance inertial sensors to measure lateral head tilt and vibrotactile elements mounted on the body to display head tilt to the user. The device has been used to study the feasibility of providing artificial feedback of head tilt to reduce postural sway during quiet standing using six healthy subjects. Two vibrotactile display schemes were used: one in which the individual vibrating elements, called tactors, were placed on the shoulders (shoulder tactors); another in which columns of tactors were placed on the right and left sides of the trunk (side tactors). Root-mean-square head-tilt angle (Tilt) and center of pressure displacement (Sway) were measured for normal subjects standing in a semi-tandem Romberg position with eyes closed, under four conditions: no balance aids; shoulder tactors; side tactors; and light touch. Compared with no balance aids, the side tactors significantly reduced Tilt (35%) and Sway (33%). Shoulder tactors also significantly reduced Tilt (44%) and Sway (17%). Compared with tactors, light touch resulted in less Sway, but more Tilt. The results suggest that healthy normal subjects can reduce their lateral postural sway using head tilt information as provided by a vibrotactile display. Thus, further testing with balance-impaired subjects is now warranted.

Adult↗
PubMed1999

Gendered sex work in the San Francisco tenderloin.

The variable "gender" rarely appears in prostitution research. Its inclusion raises the same questions brought up with respect to other areas of work: Is there a gendered perspective with respect to the work and are gender inequalities reflected in it? This study examines gender differences in the work of 140 sex workers in the San Francisco Tenderloin. As well as women and men who are workers, we include transgender workers (genetic males who present themselves as women), further accentuating differences by gender. Looking at work-specific characteristics, we find that women do not suffer inequities of income. They are, however, more prone to occupational hazards. Transgenders, who suffer the most societal discrimination, are closer to women than men in their work situation. Examining the sexuality of sex workers, the women are the least likely to enjoy sex with clients. Men report more sexual enjoyment with clients and transgenders are closer to the men in this regard. Few differences are, however, found in sexual pleasure in the personal lives of the women, men, and transgenders. A gender difference that stands out is that the men have more noncommercial sex partners than the women. Again, transgenders are more like the men, although various aspects of their condition make for some unique differences.

Adult↗
PubMed1998

AIDS risk reduction strategies among United States and Swedish heterosexual university students.

Attitudes toward sex and condoms in the U.S. are more negative and less monolithic than in Sweden. We investigated the possible effect of this on AIDS prevention strategies by comparing women and men who were heterosexual university students in the two countries (Sweden: n = 570; U.S.: n = 407). Using self-administered questionnaires, subjects were asked about their sexual activities, safer sex practices, numbers of partners, and condom use. American students took a more multifaceted approach to safer sex--combining changes in sexual activities, reductions in casual sex, and increased condom use with both steady and nonsteady partners. Swedish students took a more singular approach--consistently using condoms with nonsteady partners. It is suggested that the difference in Swedish practices results from fundamental differences in sexual attitudes between the countries.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Social class background, sexual attitudes, and sexual behavior in a heterosexual undergraduate sample.

To further the understanding of the relationship between social class and sexual attitudes and behavior, we present data from a study of undergraduate students. We look at the education of students' fathers and how it relates to students' sexual profiles. Among the men, some traditional social class differences are found, indicating that class differences persist among some upwardly mobile men. For the women, fewer social class differences appear. Further, we compare our 1992 sample of 554 college students, 19-22 years old, with a university sample of 904 similar age students from 1967, and find our sample more coitally experienced. College students today are following norms that in the past were associated with a lower educational level. Implications of our findings for class convergence theory are addressed. Reliable birth control, gains in equality by women, and the sexual images of television and other media are discussed as major factors contributing to the increased sexual permissiveness among university students of the 1990s.

Adult↗
PubMed1996

rK7-kallikrein in rat kidney and urine.

Rat Kidney is reported to contain the rK7-kallikrein gene expressed at a high mRNA level. However, there is no direct evidence that the rK7 enzyme is present in kidney or urine. We have analyzed rat kidney and urine for rK7-like enzyme activity, using distinctive properties of purified rK7 enzyme (hydrolysis of specific substrate, inhibition by SBTI). Rat urine and kidney cortex contain substantial levels of rK7-like enzyme activity. Nearly 40% of the enzyme in urine is in an active form while nearly all of the rK7 in kidney cortex is in the inactive form. Treatment with low salt diet and mineralocorticoid increases rK7 in both kidney cortex and urine approximately 2-fold. The percentage of active enzyme in urine increases markedly on this regimen.

Animals↗
PubMed1996

Evaluation of enalapril/diltiazem ER in hypertensive patients with coexisting renal dysfunction. Enalapril/Diltiazem ER in Hypertensive Renal Disease Group.

Both enalapril and long-acting diltiazem have been shown to effectively lower blood pressure (BP) in hypertensive patients. Furthermore, in clinical studies, these two agents provided beneficial renal effects in these patients when administered on a long-term basis. A combination of enalapril/diltiazem ER was evaluated in 62 patients with Stage 1-3 hypertension and coexisting renal disease. This trial used a multicenter, randomized, double-blind, parallel group design. The study consisted of a 12-week double-blind phase followed by a 6-month open-label extension phase. The combination of enalapril/diltiazem ER was shown to reduce BP following both short-term and long-term treatment phases. Patients in Renal Group I (creatinine clearance CrCl): 30-59 ml/min/1.73 m2) had decreases of -18/-16 and -25/-20 mm Hg after 12 weeks and 9 months of therapy, respectively. Those in Renal Group II (CrCl: 10-29 ml/min/1.73 m2) had similar decreases of -23/-18 and -23/-19 mm Hg at these time points. The adverse events, in both phases, were those associated with the respective monotherapies. A reduction in CrCl with a coincident decrease in proteinuria was noted for both renal groups. The combination of enalapril/diltiazem ER lowered BP and was generally well tolerated by the patients. The combination of these two agents should improve the management of hypertensive patients.

Adult↗
PubMed1995

Swedish or American heterosexual college youth: who is more permissive?

Theories of human sexuality have proposed that two factors reduce the double standard of sexuality and lead to a convergence of male and female sexual behavior: the degree of social benefits and amount of power women have in basic societal institutions and the extent to which a society accepts permissive sexual norms. As these factors increase, the strength of the double standard will decrease and the convergence between male and female behaviors will increase. Compared to the United States, Sweden has instituted more policies to promote gender equality and has been thought to accept more permissive premarital sexual attitudes. The focus of the research reported here is to examine country and gender differences in sexual attitudes and sexual behavior for a sample of university students in the United States (N = 407) and Sweden (N = 570). Results indicate that Swedish students endorsed more similar sexual standards for women and men and reported more accepting attitudes than did American students. For sexual behavior, American men reported the most sexual experience, Swedish men the least, with the women of both countries generally in the middle category. Notwithstanding this more permissive behavior on the part of American men, gender convergence with respect to sexual behavior is stronger in Sweden on several of the dimensions examined: age of first engaging in partner-related sexual activities for those who were sexually experienced, relationship with first partner, number of partners both in the last year and in their lifetime, and affective reactions to first coitus. Gender convergence, however, is weaker in Sweden than in the United States with respect to the incidence and frequency of various sexual activities and the degree of satisfaction with current sex life. Findings are discussed with respect to the questions they raise about the current theories that framed this research and the differential amount of sex education provided in the two countries.

Adult↗
PubMed1994

Homosexual foot fetishism.

262 respondents from an organization for homosexual foot fetishists provide information from a broader sample than clinical cases and allow examination of the effects of sexual preference on fetishism. Data show a wide range of feet/footwear objects to be arousing. Such interests were often associated with particular types of men, yet interests were subject to change over time. Fetishistic arousal rested on both sensual and symbolic aspects of the fetish. Symbolically, it was the theme of "masculinity" that made male feet/footwear arousing, showing parallels to "femininity" evoked by female feet/footwear for male heterosexual fetishists. For many of the respondents, fetishism did not seem to be a substitute for living persons. Respondents had intimate relationships and were able to incorporate their fetish interests into stable relationships and less intimate ones. Considerable involvement in sadomasochistic practices was also found as was involvement in the gay world. Finally, nothing about a fetishistic interest seemed to preclude the development of subcultural forms around the practice.

Adult↗
PubMed1991

The diurnal rhythm of plasma potassium: relationship to diuretic therapy.

Plasma potassium levels have been implicated in the genesis of cardiac arrhythmias, particularly in patients receiving diuretic therapy. The present study was undertaken to evaluate the stability of plasma potassium levels throughout a 28-h period. Normal volunteers (n = 8) and subjects with essential hypertension (n = 10) were studied in a clinical research center while receiving controlled dietary intakes. Plasma potassium followed a diurnal rhythm in both groups, with a peak level at 12 h and a trough level at 24 h. The average peak-to-trough difference was 0.62 +/- 0.05 mmol/L. Urinary potassium excretion also followed a diurnal rhythm, with the lowest excretory rate during the evening hours, when plasma potassium reached its nadir. Subjects with essential hypertension were restudied after 4 weeks of hydrochlorothiazide (50 mg/day) and then after an additional 4 weeks of hydrochlorothiazide (50 mg/day) and amiloride (5 mg/day). Hydrochlorothiazide alone reduced plasma potassium at all times of measurement without altering the diurnal rhythm. The combination of hydrochlorothiazide and amiloride resulted in higher plasma potassium levels in the morning, but did not significantly affect evening plasma potassium levels. The frequency of hypokalemia (K less than or equal to 3.0 mmol/L) was related to the time at which the plasma potassium was measured. We conclude that plasma potassium undergoes a diurnal rhythm and that diuretics shift this rhythm to uniformly lower values. This rhythm must be considered when defining the frequency of hypokalemia.

Adult↗
PubMed1991

Development of a radioimmunoassay to bradykinin using monoclonal antibodies.

We report here our success in the preparation of monoclonal antibody directed against bradykinin. We further demonstrate that the preparation is easier and less time-consuming compared to the preparation of polyclonal antibodies. The polyclonal antibody provides a ready source of the reagent very much required in the performance of the kinin radioimmunoassay. Limitation of this reagent was in the fact that it did not attain the desired specificity to distinguish between the kinin peptides. Nevertheless, it is interesting to note that the domains of recognition sites can be very similar for monoclonal or polyclonal response, particularly when the antigen is smaller (molecular size of about 1 Kd) as is the case with bradykinin. Our laboratory produced the first monoclonal antibodies at Brown University. These antibodies were directed to bradykinin in BALB-C mice and could recognize bradykinin, lysyl-bradykinin and met-lysyl-bradykinin. Using this reagent it is possible to develop and validate an RIA which can be utilized to measure total kinins in tissues and body fluids. Although this antibody shows similar specificity as found with the polyclonal antibody, the ease and shorter duration of this preparation may make it a reagent of choice.

Animals↗