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Biomedical subjects

J Catania

Publications and source records attributed to J Catania.

At least 19 recordsLinked to original sources

The role of acetylation in rDNA transcription.

Treatment of NIH 3T3 cells with trichostatin A (TSA), an inhibitor of histone deacetylase (HDAC), resulted in a dose-dependent increase in transcription from a rDNA reporter and from endogenous rRNA genes. Chromatin immunoprecipitation using anti-acetyl-histone H4 antibodies demonstrated a direct effect of TSA on the acetylation state of the ribosomal chromatin. TSA did not reverse inhibition of transcription from the rDNA reporter by retinoblastoma (Rb) protein, suggesting that the main mechanism by which Rb blocks rDNA transcription may not involve recruitment of deacetylases to rDNA chromatin. Overexpression of histone transacetylases p300, CBP and PCAF stimulated transcription in transfected NIH 3T3 cells. Recombinant p300, but not PCAF, stimulated rDNA transcription in vitro in the absence of nucleosomes, suggesting that the stimulation of rDNA transcription by TSA might have a chromatin-independent component. We found that the rDNA transcription factor UBF was acetylated in vivo. Finally, we also demonstrated the nucleolar localization of CBP. Our results suggest that the organization of ribosomal chromatin of higher eukaryotes is not static and that acetylation may be involved in affecting these dynamic changes directly through histone acetylation and/or through acetylation of UBF or one of the other components of rDNA transcription.

3T3 Cells↗

Understanding childhood sexual abuse as a predictor of sexual risk-taking among men who have sex with men: The Urban Men's Health Study.

OBJECTIVE: The prevalence and characteristics of childhood sexual abuse (CSA) among men who have sex with men (MSM), and links with sexual risk are explored. A model linking CSA and sexual risk among MSM is proposed. METHOD: A telephone probability sample of urban MSM (n = 2881) was recruited and interviewed between November 1996 and February 1998. The interview covered numerous health issues, including history of sexual victimization. RESULTS: One-fifth reported CSA, primarily by non-family perpetrators. Initial CSA experiences are characterized by high levels of force (43% involved physical force/weapons), and penetrative sex (78%; 46% reported attempted or actual anal intercourse). Such men are more likely than nevercoerced men to engage in high risk sex (unprotected anal intercourse with a non-primary partner or with a serodiscordant male). In multivariate analyses, the effect of childhood sexual coercion on sexual risk is mediated by substance use, patterns of sexual contacts, and partner violence, but not by adult sexual revictimization or by depression. CONCLUSIONS: Findings are interpreted within the context of social learning theory and prior research on sexual risk-taking. The high risk for CSA among MSM, which can predispose such men to patterns of HIV sexual risk, warrants new approaches in HIV prevention.

Adolescent↗

Obtaining HIV test results with a home collection test kit in a community telephone sample.

OBJECTIVES: To test the feasibility of obtaining HIV test results by home collection kit from a probability telephone sample of men who have sex with men (MSM). METHODS: A quota sample of 615 MSM previously interviewed by the Urban Men's Health Study phone survey in Chicago, Los Angeles, New York City, and San Francisco were re-contacted and offered an HIV test using an oral specimen (Orasure) home collection kit. RESULTS: Eighty percent consented to be mailed a kit, and 84% returned a specimen, for a 67% participation rate. All self-reported HIV-positive persons tested positive (77 of 77); 4 of 266 (1.5%) with a prior negative test and 2 of 69 (2.9%) with no prior positive HIV test result. Participation was associated with self-reported prior HIV test status-HIV-positive (83%), HIV-negative (68%), or no prior HIV test result (54%)-and marginally associated with New York City residence after adjustment for HIV status (odds ratio = 0.7; 95% confidence interval, 0.4-1.1; p =.08). CONCLUSIONS: These results suggest that urban MSM identified and interviewed by telephone will participate in home collection HIV testing. This methodology could be used to produce population-based estimates of HIV seroprevalence and seroincidence in MSM and could probably be extended to other populations and other viral infections.

AIDS Serodiagnosis↗

Respite rewards.

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Aged↗

Involvement of Rb family proteins, focal adhesion proteins and protein synthesis in senescent morphogenesis induced by hydrogen peroxide.

Early passage human diploid fibroblasts develop senescent morphology prematurely within a week after a 2-hour pulse treatment with low or mild dose H(2)O(2). We test here the role of cell cycle checkpoints, cytoskeletal proteins and de novo protein synthesis in senescent morphogenesis following H(2)O(2) treatment. H(2)O(2) treatment causes transient elevation of p53 protein and prolonged inhibition of Rb hyperphosphorylation. Expression of human papillomaviral E6 gene prevented elevation of p53 but did not affect senescent morphogenesis. Expression of human papillomaviral E7 gene reduced the level of Rb protein and prevented induction of senescent morphology by H(2)O(2). The mutants of the E7 gene, in which the Rb family protein binding site was destroyed, could not reduce Rb protein or prevent H(2)O(2) from inducing senescent morphology. Senescent-like cells showed enhanced actin stress fibers. In untreated cells, vinculin and paxillin preferentially distributed along the edge of the cells. In contrast, vinculin and paxillin distributed randomly and sporadically throughout senescent-like cells. E7 expression prevented enhancement of actin filament formation and redistribution of vinculin or paxillin. Neither wild-type nor E7 cells showed changes in the protein level of actin, vinculin or paxillin measured by western blot after H(2)O(2) treatment. Finally, depletion of methionine in the culture medium after H(2)O(2) treatment prevented senescent morphogenesis without affecting dephosphorylation of Rb protein. Our results suggest that senescent morphology likely develops by a program involving activated Rb family proteins, enhancement of actin stress fibers, redistribution of focal adhesion proteins and de novo protein synthesis.

Actins↗

Decisions to get HIV tested and to accept antiretroviral therapies among gay/bisexual men: implications for secondary prevention efforts.

The objective of this study was to report prevalence rates of adherence by HIV-seropositive individuals to medical recommendations for the treatment of HIV infection, a behavioral pattern referred to as AIDS secondary prevention. We report cross-sectional data (n = 2,593) from two household-based and two bar-based samples of gay/bisexual men, gathered in 1992 in Tucson, Arizona, and Portland, Oregon. The main outcome variables were prevalence of HIV antibody testing and adherence to recommended secondary prevention behaviors to prevent onset of AIDS symptoms. Approximately one-third of the gay/bisexual men in these samples do not know their current HIV status. Of the gay/bisexual men who do know that they are HIV-seropositive, approximately three-fourths adhere to each of the secondary prevention recommendations, as appropriate to their stage of disease progression. In a multivariate logistic model, three variables distinguished between HIV-seropositive men who did and did not adhere: perceived antiviral treatment norms (OR = 1.4, CI = 1.1-1.7), perceived efficacy of secondary prevention treatments (OR = 1.4, CI = 1.1-1.7), and quality of the relationship with one's health-care provider (OR = 2.5, CI = 1.6-4.0). These findings indicate that efforts to support AIDS secondary prevention behaviors can occur not only through health education to change the perceptions of at-risk communities about the options available to delay the onset of opportunistic infections among HIV-seropositive individuals but also by enhancing effective doctor/patient communication.

AIDS Serodiagnosis↗

Evaluation of an HIV risk reduction intervention among African-American homosexual and bisexual men.

OBJECTIVE: To provide the first data which evaluates an HIV risk reduction intervention designed to reduce HIV high-risk sexual behavior in African-American homosexual and bisexual men. SUBJECTS: Participants (n = 318) were recruited from bars, bathhouses, and erotic bookstores, and through homosexual African-American organizations, street out-reach, media advertisements, and personal referrals of individuals aware of the study. METHODS: Participants were randomized into a single or triple session experimental group or a wait-list control group. Both experimental interventions included AIDS risk education, cognitive-behavioral self-management training, assertion training, and attempts to develop self-identity and social support. Data collection involved assessments of self-reported changes in sexual behavior at 12- and 18-month follow-up. RESULTS: Participants in the triple session intervention greatly reduced their frequency of unprotected anal intercourse (from 46 to 20%) at the 12-month follow-up evaluation and (from 45% to 20%) at the 18-month follow-up evaluation. However, levels of risky behavior for the control group remained constant (from 26 to 23% and from 24 to 18%) at 12- and 18-month follow-up evaluations, respectively. In addition, levels of risky behavior for the single session intervention decreased only slightly (from 47 to 38% and from 50 to 38%) at the 12- and 18-month follow-up evaluations, respectively. CONCLUSIONS: Results were interpreted to demonstrate the superiority of a triple session over a single session intervention in reducing risky sexual behavior in this cohort.

Adult↗

Age-associated alterations in thirst and arginine vasopressin in response to a water or sodium load.

We have examined simultaneous changes in thirst, plasma osmolality and arginine vasopressin, after oral water loading or hypertonic saline infusion. The studies were carried out in the same subjects, comprising young controls aged 26.8 years (SD 4.8, n = 10) and health status-defined elderly people aged 72.1 years (SD 3.1, n = 10). Water loading caused significant falls in plasma osmolality (p < 0.001) and thirst (p < 0.001), but there was no variation with age. Infusion with 462 mmol/l of sodium chloride increased plasma osmolality significantly (p < 0.001), but there was no variation with age (p = 0.12). The perception of thirst during the osmotic loading experiment was recorded differently by the two age groups (p < 0.0001). However, linear regression analysis showed no age difference in the relationship between thirst and plasma osmolality during osmotic loading. During osmotic loading the relationship between the plasma concentration of arginine vasopressin in response to increasing plasma osmolality varied significantly (slope: p = 0.02; intercept: p = 0.02). Plasma arginine vasopressin rose more rapidly with increasing plasma osmolality in old subjects.

Adult↗

AIDS risk behaviors among late middle-aged and elderly Americans. The National AIDS Behavioral Surveys.

OBJECTIVES: Although 10% of all acquired immunodeficiency syndrome (AIDS) cases diagnosed in the United States have been among Americans aged 50 years of age or older, little attention has been devoted to understanding AIDS risk-taking behaviors among middle-aged or older Americans. This study describes the prevalence of AIDS risk among Americans aged 50 years of age or older. DESIGN AND STUDY POPULATION: We present data from the National AIDS Behavioral Surveys, two large cross-sectional national surveys taken in 1990-1991. MAIN OUTCOME VARIABLE: Prevalence of risk behaviors for human immunodeficiency virus (HIV) transmission and of HIV testing. RESULTS: Findings from both surveys provide replication of several important points. First, the prevalence of having at least one risk factor for HIV infection was about 10% among Americans aged 50 years or older in both samples. Very small proportions of Americans past the age of 50 years with a known behavioral risk for HIV infection used condoms during sex or had undergone HIV testing. At-risk Americans past the age of 50 years were one sixth as likely to use condoms during sex and one fifth as likely to have been tested for HIV as a comparison group of at-risk individuals in their 20s. CONCLUSIONS: Despite the fact that HIV infection is clearly present among those past the age of 50 years, a small proportion of individuals in this age group take behavioral risks for HIV infection. High-risk individuals older than 50 years are much less likely to have adopted AIDS prevention strategies than are younger individuals who engage in the same behavioral risks.

AIDS Serodiagnosis↗

HIV antibody testing among those at risk for infection. The National AIDS Behavioral Surveys.

OBJECTIVE: To determine the prevalence of testing for human immunodeficiency virus (HIV) antibody among adults with various risk factors for infection, particularly those residing in large metropolitan areas where the bulk of cases of acquired immunodeficiency syndrome (AIDS) have occurred. DESIGN: A nationwide, population-based telephone survey eliciting testing, sexual, and injection drug use histories. PARTICIPANTS: A total of 2673 randomly chosen US residents and 8263 randomly chosen residents of 23 metropolitan areas containing 64% of reported cases of AIDS. INTERVENTIONS: None. MAIN OUTCOME MEASURE: Testing for HIV antibody. MAIN RESULTS: Overall, rates of individuals ever tested were only slightly higher in the urban areas (23%) than in the nation as a whole (21%). Testing frequencies were low among all risk groups (less than 40%), except men engaging in same-sex sexual activity (60%) and male and female injection drug users (46% and 73%, respectively). The low rate of testing (35%) among the largest risk group, heterosexual men and women engaging in unprotected sexual intercourse with multiple partners, was particularly worrisome. CONCLUSIONS: To encourage antibody testing among the many at risk for infection who have not yet been tested, promotional campaigns should explain the universal susceptibility to infection among those at risk, and the availability of prophylactic medical therapies and social support services to persons who are HIV-seropositive. As there were comparable levels of risk-taking behavior among subjects in both samples, these campaigns must be designed to reach all segments of the population.

AIDS Serodiagnosis↗

Risk for AIDS in multiethnic neighborhoods in San Francisco, California. The population-based AMEN Study.

To examine the actual and potential spread of human immunodeficiency virus (HIV) from an acquired immunodeficiency syndrome (AIDS) epicenter to surrounding neighborhoods, we studied the prevalence of the viral infection and AIDS risk behaviors from 1988 to 1989 in a representative sample of unmarried whites, African Americans, and Hispanics living in San Francisco. We surveyed 1,770 single men and women aged 20 to 44 years (a 64% response rate) in a random household sample drawn from 3 neighborhoods of varying geographic and cultural proximity to the Castro District where the San Francisco epidemic began. Of 1,369 with blood tests, 69 (5%) had HIV antibodies; all but 5 of these reported either homosexual activity (32% HIV-positive; 95% confidence interval [CI] = 23%, 41%), injection drug use (5% HIV-positive; CI = 1%, 14%), or both (59% HIV-positive; CI 42%, 74%). Homosexual activity was more common among white men than among African-American or Hispanic men, but the proportion of those infected was similar in the 3 races. Both the prevalence of homosexually active men and the proportion infected were much lower in the 2 more outlying neighborhoods. Risk behaviors in the past year for acquiring HIV heterosexually--sex with an HIV-infected person or homosexually active man or injection drug user, unprotected sexual intercourse with more than 4 partners, and (as a proxy) having a sexually transmitted disease--were assessed in 1,573 neighborhood residents who were themselves neither homosexually active men nor injection drug users. The prevalence of reporting at least 1 of these risk behaviors was 12% overall, and race-gender estimates ranged from 5% among Hispanic women to 21% among white women. We conclude that in San Francisco, infection with HIV is rare among people who are neither homosexually active nor injection drug users, but the potential for the use spread of infection is substantial, as 12% of this group reported important risk behaviors for acquiring the virus heterosexually.

Acquired Immunodeficiency Syndrome↗

A comparison of younger and older gay men's HIV risk-taking behaviors: the Communication Technologies 1989 Cross-Sectional Survey.

Data from the 1989 Communication Technologies cross-sectional survey of gay men in San Francisco indicate that both levels and correlates of sexual risk are different between younger and older gay men. Gay men under the age of 30 report higher risk behavior for human immunodeficiency virus (HIV) infection than do gay men who are 30 years of age or older. Further, the set of correlates of unprotected anal intercourse are different between younger and older gay men. Both young and old gay men report that having a primary partner and a lower perceived impact of the AIDS epidemic on their sexual behavior are associated with risk. However, among young gay men, reporting a lower attributed risk for HIV infection to unprotected anal intercourse, higher concern about AIDS risks, and shorter length of residence in San Francisco are positively correlated with risk-taking behavior. These associations were not statistically significant among gay men 30 years of age or older. It appears that the circumstances and/or reasons for taking sexual risk are different between older and younger gay men. Prevention programs must be designed so that they are sensitive to the needs of each generation of gay men.

Adolescent↗

Temporomandibular joint findings in pediatric populations and young adults: a critical review.

The etiology, diagnosis and treatment of temporomandibular joint (TMJ) pain and dysfunction is a controversial subject. There are varying opinions regarding the contribution of occlusion (malocclusion) to the development of mandibular dysfunction and further, the contribution of occlusal alterations (orthodontic and restorative) to the development of pain and dysfunction. Epidemiologic investigations suggest there is a high incidence of subjective and objective symptoms in the pediatric population. Observations on incisal relationships, condyle position and joint sounds, and comparisons to controls seem to suggest that these factors are not the cause of pain or dysfunction. The purpose of this review is: (1) to bring the clinician's attention existing published information reporting the presence of symptoms in children, (2) to evaluate selected information in young adults, (3) to question anecdotal information on the etiology of TMJ problems. It is not in the purview of this paper to determine the overall etiology of TMJ dysfunction.

Adolescent↗

Hypothesis: a history of hypothyroidism or a family history of pernicious anaemia are useful in identifying masked pernicious anaemia in elderly patients with microcytic hypochromic anaemia.

Of 2200 consecutive patients admitted to an acute geriatric unit, 58 had microcytic hypochromic anaemia. Twenty of these (34%) had serum vitamin B12 below the normal range. Eleven (19%) had malabsorption of vitamin B12 in eight of whom (14%) this was due to pernicious anaemia (PA). This study re-emphasizes the need for screening for PA in patients with microcytic hypochromic anaemia, particularly those with a family history or who have recognized associated diseases.

Aged↗

Osteitis pubis in a 78 year old female.

Osteitis pubis has been reported following pelvic surgery, childbirth and in athletes. We describe a case involving an elderly woman, in which none of the predisposing factors were present. Difficulties in diagnosis, with particular reference to the elderly, are highlighted.

Acute Disease↗

Determination of 5-methylcytosine by acid hydrolysis of DNA with hydrofluoric acid.

Quantitation of 5-methylcytosine in DNA after acid hydrolysis has been inaccurate because deamination of cytosine and 5-methylcytosine occurs during the hydrolysis procedure. There is little information in the literature regarding the use of hydrofluoric acid (HF) for DNA hydrolysis and we have therefore undertaken a systematic study of this process. The deoxyribonucleotides of cytosine and 5-methylcytosine were shown not to undergo detectable levels of deamination during prolonged periods (up to 24 h) at 80 degrees C in 48% HF. Kinetic studies show that the release of purine and pyrimidine bases was complete by 4 h under these conditions. Analysis of the 5-methylcytosine content of DNA from various tissues gave levels that were very close to the values reported in the literature. This method is ideally suited for the determination of the overall cytosine methylation levels in DNA.

5-Methylcytosine↗