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Biomedical subjects

M H Katz

Publications and source records attributed to M H Katz.

At least 37 records · Page 2Linked to original sources
PubMed2000

Low estimates of HIV seroconversions among clients of a drug treatment clinic in San Francisco, 1995 to 1998.

We estimated HIV incidence among injection drug users attending a drug treatment clinic in San Francisco from 1995 to 1998 using two methods. An anonymous sequential testing method identified no seroconversions among clients seen more than once during the period (one-sided upper 95% confidence limit 1.02 per 100 person-years). A sensitive/less sensitive immunoassay testing strategy detected no early infections (one-sided upper 95% confidence limit 1.90% per year). Methods were concordant and feasible in the setting. Although detection of no new HIV infections in this population of injection drug users (IDUs) is encouraging, epidemiologic studies among IDUs not in treatment are needed to monitor the HIV epidemic effectively.

Adult↗
PubMed2000

Prevalence and predictors of unmet need for supportive services among HIV-infected persons: impact of case management.

BACKGROUND: Previous research has indicated that the needs of persons infected with human immunodeficiency virus (HIV) for supportive services often go unmet. Although case management has been advocated as a method of decreasing unmet needs for supportive services, its effectiveness is poorly understood. OBJECTIVES: To assess the prevalence of need and unmet need for supportive services and the impact of case managers on unmet need among HIV-infected persons. RESEARCH DESIGN: National probability sample. PARTICIPANTS: A total of 2,832 HIV-infected adults receiving care. MEASURES: Need and unmet need for benefits advocacy, housing, home health, emotional counseling, and substance abuse treatment services. RESULTS: Sixty-seven percent of the sample had a need for at least one supportive service, and 26.6% had an unmet need for at least one service in the previous 6 months. Contingent unmet need (unmet need among persons who needed the service) was greatest for benefits advocacy (34.6%) and substance abuse treatment (27.6%). Fifty-seven percent of the sample had had contact with their case manager in the previous 6 months. In multiple logistic regression analysis, with adjustment for covariates, having a case manager was associated with decreased unmet need for home healthcare (OR =0.39; 95% CI = 0.25-0.60), emotional counseling (OR = 0.54; 95% CI = 0.38-0.78), and any unmet need (OR = 0.70; 95% CI = 0.54-0.91). An increased number of contacts with a case manager was significantly associated with lower unmet need for home health care, emotional counseling, and any unmet need. CONCLUSIONS: Need and unmet need for supportive services among HIV-infected persons is high. Case management programs appear to lower unmet need for supportive services.

Adult↗
PubMed2000

Prevalence and correlates of herpes simplex virus type 2 infection in a population-based survey of young women in low-income neighborhoods of Northern California. The Young Women's Survey Team.

BACKGROUND: Herpes simplex virus type 2 (HSV-2) is one of the most common sexually transmitted infections and may enhance transmission of HIV. However, population-based estimates of HSV-2 prevalence and correlates of infection are rare. GOALS: To obtain population-based estimates of HSV-2 prevalence and to identify demographic and sexual behavioral correlates of infection among women in low-income communities of Northern California. STUDY DESIGN: A randomized, single-stage, cluster sample, cross-sectional survey of women age 18 to 29 years who reside in 1990 US Census block groups at the lowest tenth percentile for household income. RESULTS: The survey-weighted prevalence of HSV-2 infection was 34.8% (95% CI, 30.4-39.2). Factors independently associated with HSV-2 seropositivity were black race, older age, lower income, parity, greater number of lifetime male sexual partners, earlier onset of sexual intercourse, sex work, history of sexually transmitted disease (STD), and cocaine use. CONCLUSION: The high prevalence of HSV-2 and the strong correlation with sexual risk underscores the potential for further spread of STD, including HIV, in this young population.

Adolescent↗
PubMed2000

Helping the urban poor stay with antiretroviral HIV drug therapy.

Recent studies have documented dramatic decreases in opportunistic infections, hospitalizations, and mortality among HIV-infected persons, owing primarily to the advent of highly active antiretroviral medications. Unfortunately, not all segments of the population living with HIV benefit equally from treatment. In San Francisco, only about 30% of the HIV-infected urban poor take combination highly active antiretroviral medications, as compared with 88% of HIV-infected gay men. Practitioners who care for the urban poor are reluctant to prescribe these medications, fearing inadequate or inconsistent adherence to the complicated medical regimen. Persons typically must take 2 to 15 pills at a time, 2 to 3 times a day. Some of the medications require refrigeration, which may not be available to the homeless poor. Most homeless persons do not have food available to them on a consistent schedule. Therefore, they may have difficulty adhering to instructions to take medications only on an empty stomach or with food. Lack of a safe place to store medications may be an issue for some. In addition, many urban poor live with drug, alcohol, or mental health problems, which can interfere with taking medications as prescribed. Inconsistent adherence to medication regimens has serious consequences. Patients do not benefit fully from treatments, and they will become resistant to the medications in their regimen as well as to other medications in the same classes as those in their regimen. Development of resistance has implications for the broader public health, because inadvertent transmission of multidrug-resistant strains of HIV has been demonstrated. Concern that the urban poor will not adhere to highly active antiretroviral medication regimens has led to debate on the role of clinicians and public health officials in determining who can comply with these regimens. Rather than define the characteristics that would predict adherence to these regimens, the San Francisco Department of Public Health created a program to support adherence among those who may have the greatest difficulty complying with complicated highly active antiretroviral medication regimens. The program, dubbed the Action Point Adherence Project, was conceived through a community planning process in preparation for a city-wide summit on HIV/AIDS that took place in January 1998. Action Point is funded by the city and the county of San Francisco. Now in its 10th month, the program continues to show promising evidence of improving clients' biological and social indicators.

Adult↗
PubMed2000

Delays in seeking HIV care due to competing caregiver responsibilities.

OBJECTIVES: This study sought to describe the characteristics of HIV-infected persons who delay medical care for themselves because they are caring for others. METHODS: HIV-infected adults (n = 2864) enrolled in the HIV Cost and Services Utilization Study (1996-1997) were interviewed. RESULTS: The odds were 1.6 times greater for women than for men to put off care (95% confidence interval [CI] = 1.2, 2.2); persons without insurance and with CD4 cell counts above 500 were also significantly more likely to put off care. Having a child in the household was associated with putting off care (odds ratio [OR] = 1.8, 95% CI = 1.4, 2.3). CONCLUSIONS: Women or individuals with a child in the household should be offered services that might allow them to avoid delays in seeking their own medical care.

Adult↗
PubMed1999

Detection of early HIV infection and estimation of incidence using a sensitive/less-sensitive enzyme immunoassay testing strategy at anonymous counseling and testing sites in San Francisco.

Timely estimates of HIV incidence are needed to monitor the epidemic and target primary prevention but have been difficult to obtain. We applied a sensitive/ less-sensitive (S/LS) enzyme immunoassay (EIA) testing strategy to stored HIV-positive sera (N = 452) to identify early infections, estimate incidence, and characterize correlates of recent seroconversion among persons seeking anonymous HIV testing in San Francisco from 1996 to 1998 (N = 21,292). Sera positive on a sensitive EIA but negative on a less-sensitive EIA were classified as early HIV infections; sera positive on both EIA were classified as long standing. Seventy-nine sera were from people with early HIV infection. Estimated HIV incidence was 1.1% per year (95% confidence interval [CI], 0.68%-1.6%) overall and 1.9% per year (95% CI, 1.2%-3.0%) among men who have sex with men (MSM). Early HIV infection among MSM was associated with injection drug use, unprotected receptive anal sex, and multiple sex partners in the previous year. No temporal trend in HIV incidence was noted over the study period. The S/LS strategy provides a practical public health tool to identify early HIV infection and estimate HIV incidence in a variety of study designs and settings.

Adult↗
PubMed1999

A membrane lipid imbalance plays a role in the phenotypic expression of cystic fibrosis in cftr(-/-) mice.

A deficiency in essential fatty acid metabolism has been reported in plasma from patients with cystic fibrosis (CF). However, its etiology and role in the expression of disease is unknown. The objective of this study was to determine whether alterations in fatty acid metabolism are specific to CF-regulated organs and whether they play a role in the expression of disease. A membrane lipid imbalance was found in ileum, pancreas, and lung from cftr(-/-) mice characterized by an increase in phospholipid-bound arachidonic acid and a decrease in phospholipid-bound docosahexaenoic acid (DHA). This lipid imbalance was observed in organs pathologically affected by CF including lung, pancreas, and ileum and was not secondary to impaired intestinal absorption or hepatic biosynthesis of DHA. As proof of concept, oral administration of DHA to cftr(-/-) mice corrected this lipid imbalance and reversed the observed pathological manifestations. These results strongly suggest that certain phenotypic manifestations of CF may result from remediable alterations in phospholipid-bound arachidonic acid and DHA levels.

Administration, Oral↗
PubMed1999

Home collection versus publicly funded HIV testing in San Francisco: who tests where?

We examined records of all HIV antibody tests performed at anonymous publicly funded (PF) sites and by home collection (HC) testing for residents of San Francisco from August 1996 to December 1997. Although far fewer tests were performed by HC testing than at PF sites (715 versus 8712, respectively), a higher proportion of HC testers reported no prior history of HIV testing (33.1% versus 17.9%). HIV seroprevalence was higher among PF tests (1.8%) than among HC tests (0.9%). Compared with PF testers, HC testers were less likely to be gay men, lesbian or bisexual women, heterosexual women, African American, or Latino. HC testers were more likely to report sex with a known HIV-positive partner. HC testers were also more likely to reside in affluent neighborhoods. HC testing reaches some high-risk persons who may not otherwise seek PF testing, although, overall, the risk profile of HC testers appeared lower than that of PF testers. HC testing reaches some individuals who can financially afford HC testing, thus saving public prevention resources for hard-to-reach, high-risk populations.

AIDS Serodiagnosis↗
PubMed1999

The impact of the 1993 AIDS case definition on the completeness and timeliness of AIDS surveillance.

OBJECTIVE: To assess the impact of the 1993 change in the AIDS case definition on the completeness and timeframe of AIDS case reporting in San Francisco. DESIGN: Retrospective review of records: billing records, list of selected diagnostic codes, radiology logs, ophthalmology clinic records, and patient registries at a selection of hospitals, clinics, and physician offices. SETTING: Hospitals, public/community health clinics, and physician offices. MAIN OUTCOME MEASURES: The completeness of reporting and the median reporting delay was calculated for hospitals, clinics, and physician offices. RESULTS: Reporting was 97% complete. Reporting from physician offices was less complete (75%) than from other facilities. The median reporting delay was 1 month and was shorter for persons who met the 1993 AIDS case definition (1 month) than for persons who met the 1987 case definition (3 months). CONCLUSIONS: AIDS case reporting in San Francisco is highly complete but less so for persons diagnosed at physician offices. The 1993 AIDS case definition has resulted in more timely reporting. Health departments should consider efforts to improve reporting from private physician offices and should evaluate the use of laboratory-initiated CD4 reporting.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Post-exposure prophylaxis for HIV.

The advent of preventive treatment for HIV highlights the urgent need for basic, clinical, and epidemiologic research targeting the pathogenesis and prevention of cutaneous and mucosal infection. In addition, the impact of HIV prophylaxis on the frequency of risk behaviors and antiretroviral drug resistance, especially in cities with high HIV prevalence, must be evaluated. In our view, the available data (albeit not definitive) are strong enough to support the provision of post-exposure prophylaxis in select cases of sexual and injection drug use exposure in addition to occupational exposures. However, post-exposure treatment should be used judiciously and only in the context of a comprehensive prevention program. Ultimately, primary exposure prevention, whether in health care facilities or in the community, is the most important strategy to prevent AIDS.

Anti-HIV Agents↗
PubMed1999

Postexposure prophylaxis for human immunodeficiency virus (HIV) infection following sexual assault.

Although the 1998 Centers for Disease Control and Prevention's guidelines for treatment of sexually transmitted diseases recommend offering postexposure prophylaxis for human immunodeficiency virus (HIV) infection following sexual assault, there are no detailed protocols on how to provide this treatment. Postexposure prophylaxis has been shown to lower the risk of seroconversion following occupational exposure to HIV by 81%, but has not yet been evaluated following sexual exposure. Though scientific data are limited, victims of sexual assault should be given the best information available to make an informed decision regarding postexposure prophylaxis. When the choice is made to take medications to prevent HIV infection, treatment should be initiated as soon as possible, but no later than 72 hours following the assault, and should be continued for 28 days. HIV postexposure prophylaxis should be provided in the context of a comprehensive treatment and counseling program that recognizes the physical and psychosocial trauma experienced by victims of sexual assault.

Anti-HIV Agents↗
PubMed1999

Linking clients from HIV antibody counseling and testing to prevention services.

The effectiveness of HIV antibody counseling and testing as a prevention intervention is limited: persons testing seronegative do not usually change their risk behaviors, some actually increase their risk behaviors, and decreases in risk behaviors are usually short-lived. Referrals to additional prevention and other needed services are therefore recommended, although the extent and determinants of referral provision for persons testing seronegative are unknown. We assessed the prevalence of referrals and the association between risk behaviors and prevention referrals among seronegatives. We reviewed HIV testing and referral data on all persons receiving confidential seronegative test results in San Francisco (SF) in the first 10 months of 1995 (n = 5,595), and gathered more detailed referral information at the municipal STD clinic from November 1995 through May 1996 (n = 747). The overall prevalence of referrals was low: a referral was given to 19.1% of the SF sample and 10.6% of the STD clinic sample; 15.4% of the SF sample and 5.9% of the STD clinic sample received a prevention referral. Injection drug users (IDUs) were the most likely to receive a prevention referral (48.5% of SF IDUs, 36.4% of STD clinic IDUs); men having sex with men and women with high-risk partners were also more likely to get a prevention referral than others. For SF IDUs, unsafe sex and needle sharing were not associated with an increased likelihood of receiving a prevention referral. Opportunities to link high-risk clients from counseling and testing to HIV prevention services are being missed. The referral component of HIV counseling and testing should be improved.

AIDS Serodiagnosis↗
PubMed1999

The impact of competing subsistence needs and barriers on access to medical care for persons with human immunodeficiency virus receiving care in the United States.

OBJECTIVES: To examine whether competing subsistence needs and other barriers are associated with poorer access to medical care among persons infected with human immunodeficiency virus (HIV), using self-reported data. DESIGN: Survey of a nationally representative sample of 2,864 adults receiving HIV care. MAIN INDEPENDENT VARIABLES: Going without care because of needing the money for food, clothing, or housing; postponing care because of not having transportation; not being able to get out of work; and being too sick. MAIN OUTCOME MEASURES: Having fewer than three physician visits in the previous 6 months, visiting an emergency room without being hospitalized; never receiving antiretroviral agents, no prophylaxis for Pneumocystis carinii pneumonia in the previous 6 months for persons at risk, and low overall reported access on a six-item scale. RESULTS: More than one third of persons (representing >83,000 persons nationally) went without or postponed care for one of the four reasons we studied. In multiple logistic regression analysis, having any one or more of the four competing needs independent variables was associated with significantly greater odds of visiting an emergency room without hospitalization, never receiving antiretroviral agents, and having low overall reported access. CONCLUSIONS: Competing subsistence needs and other barriers are prevalent among persons receiving care for HIV in the United States, and they act as potent constraints to the receipt of needed medical care. For persons infected with HIV to benefit more fully from recent advances in medical therapy, policy makers may need to address nonmedical needs such as food, clothing, and housing as well as transportation, home care, and employment support.

Adult↗
PubMed1999

Endocytosis at the apical plasma membrane of pancreatic acinar cells is regulated by tyrosine kinases.

We have shown that endocytosis at the apical plasma membrane of pancreatic acinar cells is regulated by the pH of the acinar lumen and is associated with cleavage of GP2, a glycosyl phosphatidylinositol-anchored protein. The aim of this study was to determine the transduction pathway by which endocytosis is activated. Apical endocytosis was studied in rat pancreatic acini by prestimulation with cholecystokinin followed by measurement of horseradish peroxidase (HRP) uptake. Lanthanum, staurosporine, and forskolin had no effect on HRP uptake. Cytochalasin D significantly inhibited endocytosis, indicating a dependence on actin filament integrity. Genistein and the specific tyrphostin inhibitor B42 also inhibited HRP uptake, implicating tyrosine kinases in the regulation of HRP uptake. With the use of an Src kinase-specific substrate, Src kinase activity was temporally related to activation of endocytosis. The tyrosine-dependent phosphorylation of an 85-kDa substrate in both rat and mouse pancreatic acini correlated with Src kinase activation and pH-dependent regulation of HRP uptake. These results indicate that apical endocytosis in acinar cells is associated with tyrosine kinase activation and is dependent on the actin cytoskeleton.

Animals↗
PubMed1999

Experiences of 100 men who have sex with men using the Reality condom for anal sex.

A self-administered, anonymous questionnaire examining opinions and experiences of using Reality, the "female" condom, for anal sex was completed by a convenience sample of 100 men who have sex with men (MSM). Eighty-six percent of respondents said they would use Reality again; 54% would rather use Reality than penile condoms. Acceptability was higher among MSM who were HIV positive, in nonmonogamous relationships, or who had serodiscordant partners. Negative experiences included: difficulty inserting (33%), irritation (17%), bunching up (12%), unpleasant texture (10%), and noise (9%). Breakage was reported three times in 334 episodes of use. Although no available data compare preferences and efficacy of Reality to penile condoms, Reality is a welcome alternative for some MSM who have difficulty consistently using penile condoms and probably reduces HIV transmission compared with unprotected anal sex. Research to more definitively assess Reality as a risk reduction method for MSM is greatly needed.

Attitude to Health↗
PubMed1998

Continuing high prevalence of HIV and risk behaviors among young men who have sex with men: the young men's survey in the San Francisco Bay Area in 1992 to 1993 and in 1994 to 1995.

Several recent studies have shown high rates of HIV infection and risk behavior among young men who have sex with men (MSM). To assess the direction of the epidemic in this population, we replicated a venue-based study performed in the San Francisco Bay Area during 1992 and 1993. From May 1994 to September 1995, we surveyed 675 MSM aged between 17 and 22. After statistical adjustment for age, ethnicity, residence, and site of recruitment, seroprevalence did not change significantly between the 1992 to 1993 (8.4%) and the 1994 to 1995 (6.7%) surveys. Similarly, no significant changes were found in the rates during the previous 6 months of unprotected receptive anal intercourse (23.4% versus 24.9%), injection drug use (8.0% versus 7.8%), or needle sharing among injection drug users (56.3% versus 64.5%) between the two surveys. Despite the increased attention that the problem of high risk behavior among young MSM has received, effective prevention interventions for MSM are needed as profoundly now as they had been several years ago.

Adolescent↗
PubMed1998

Association between drug use patterns and HIV risks among homeless, runaway, and street youth in northern California.

We examined relationships between drug use patterns and HIV risk behaviors among 1121 street-recruited homeless, runaway, and 'street youth' in Northern California. Comparisons demonstrated that youth using any heroin, methamphetamine, or cocaine exhibited more sexual risks than non-users, while primary stimulant and combined heroin/stimulant users showed greatest sexual risk. Combined heroin/stimulant injectors showed higher risk injection practices than primary heroin or primary stimulant injectors, including frequent injections and backloading syringes. Interventions for street youth should be tailored to current drug use patterns since those using combinations of heroin and stimulants may require more comprehensive prevention, support and treatment services.

Adolescent↗