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Biomedical subjects

M Hogben

Publications and source records attributed to M Hogben.

14 recordsLinked to original sources
PubMed2005

The impact of the transmission dynamics of the HIV/AIDS epidemic on sexual behaviour: a new hypothesis to explain recent increases in risk taking-behaviour among men who have sex with men.

Increases in sexually transmitted infections and related high-risk behaviours have been reported among men who have sex with men (MSM) in industrialised countries when effective antiretroviral therapy against HIV infection has become widely available, in the mid-nineties. The reasons for these increases are not fully understood and often conflicting. Prevention fatigue, relapses to unsafe sex, as well as optimism toward the risk of developing AIDS among people living with HIV are not unique to the era of antiretroviral therapy (ART). This has led researchers to highlight the need to investigate other potential reasons that could explain the increase in high-risk taking following the ART introduction. We put forward the hypothesis that the change in the transmission dynamics of the HIV/AIDS epidemic before and after the introduction of ART has contributed to this change in high-risk behaviour. It is suggested that a decline in sexual risk activities has occurred at the population-level following the initial spread of the HIV/AIDS epidemic because AIDS mortality and severe morbidity disproportionately depleted the pool of high-risk taking individuals. As a result, non-volitional changes may have occurred at the individual-level over time because the depletion of this pool of high-risk individuals made it more difficult for the remaining high-risk taking individuals to find partners to engage in risky sex with. Following its introduction, ART has facilitated the differential replenishment of the pool of individuals willing to engage in high-risk taking behaviours because ART reduces AIDS mortality, and morbidity. Consequently, high-risk taking individuals who had previously reduced their level of risky sex non-volitionally (i.e., as a result of the reduced availability of high-risk partners) were able to resume their initial high-risk practices as the pool of high-risk taking individuals replenished over time. Thus, a fraction of the recently reported increase in high-risk sexual activities may be secondary to the fact that those MSM who were unable to engage in their desired high-risky sexual activities (because of reduced availability) are now able to revert to them as the availability of men willing to engage in risky sexual behaviours increases partly due to ART. Therefore, we suggest that a fraction of the changes in individual behaviour are non-volitional and can be explained by a change in "sexual partner availability" due to the transmission dynamics of HIV/AIDS before and after ART. The hypothesis is formulated and explained using simple social network diagrams and the Theory of Planned Behaviour. We also discuss the implication of this hypothesis for HIV prevention.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Syphilis partner notification with men who have sex with men: a review and commentary.

BACKGROUND: Eight US cities experienced large outbreaks of syphilis among men having sex with men (MSM), beginning during 2000-2001. Provider-assisted partner notification via disease intervention specialists has traditionally composed a large part of syphilis control efforts. OBJECTIVES: Report current effectiveness of syphilis partner notification for MSM and identify related problems and solutions. RESULTS: One thousand five hundred seventeen MSM diagnosed with syphilis claimed 10,254 sex partners. Many claimed anonymous partners (median = 65%), or provided insufficient locating information (median = 42%). Median cases found per index case were 0.09 (total = 116), although an additional 197 partners had been previously treated. Principal impediments to partner notification fell into 3 areas: (1) diagnosis outside health department settings delayed interviews, (2) partners were often anonymous, and (3) mistrust among MSM, public health professionals, and health care providers in private settings. CONCLUSIONS: Characteristics of the current outbreaks among MSM make traditional partner notification more difficult than in the past. Some modifications, complements, and even alternatives to partner notification are either planned or in operation.

Cities↗
PubMed2004

Physicians' opinions about partner notification methods: case reporting, patient referral, and provider referral.

BACKGROUND: The United States has relied upon partner notification strategies to help break the chain of infection and re-infection for sexually transmitted diseases (STD). Physicians are a vital link in the system of STD control, but little is known of physician opinions about partner notification strategies. METHODS: We collected opinions about partner notification from a national probability sample of physicians in specialties diagnosing STDs. Physicians responded to 17 questions about three relevant forms of STD partner notification: patient based referral, provider based referral, and case reporting. RESULTS: Exploratory factor analyses showed that responses for each form of partner notification could be grouped into four categories: perceived practice norms, infection control, patient relationships, and time/money. Multivariate analyses of the factors showed that physicians endorsed patient based referral most favourably and provider based referral least favourably. CONCLUSION: Physicians' opinions about partner notification strategies appear to reflect objective reality in some areas, but not in others. Strategies that improve the fit between physicians' opinions and effective notification are needed: some are discussed here.

Adult↗
PubMed2003

National survey of doctors' actions following the diagnosis of a bacterial STD.

OBJECTIVES: Little is known about the post-STD diagnosis management practices of community based doctors. The purpose of this study was to describe the reported actions that doctors take after diagnosing gonorrhoea, chlamydia, or syphilis and to determine if these actions differ across the three STDs. METHODS: A random national sample of 7300 doctors (70% response rate) practising in five medical specialties responded to 13 questions related to STD management. Mean differences across STDs were examined using the General Linear Model function of SPSS. RESULTS: Most doctors reported instructing patients to abstain from sex during treatment, to use condoms, and to inform their sexual partners of their exposure after diagnosing gonorrhoea, chlamydia, or syphilis. For syphilis, however, doctors were less likely to treat the patients presumptively and to give them drugs for their partners; and more likely to collect partner information, to follow up with the patient to see if the partner was referred for treatment and to send patient information to the health department. CONCLUSIONS: Doctors' post-STD diagnosis actions were similar for gonorrhoea and chlamydia compared to syphilis. Study findings suggest low levels of STD case reporting and partner follow up by doctors in the sample. Interventions are needed to educate community based doctors about the importance of partner follow up and case reporting in the management of STDs.

Adult↗
PubMed1999

The influence of HIV-related knowledge and exposure fears on behavior change and incident STDs.

Using a sample of 678 HIV-seronegative women, we measured self-reports of HIV-related cognitions, specifically knowledge, perceived exposure risks, and outcome expectations. We also ascertained prevalent and incident bacterial STDs and measured self-reports of behavioral risk reductions. We tested for associations between (a) cognitions and STD prevalence, (b) cognitions and incident STDs, (c) cognitions and behavioral risk reductions, and (d) risk reductions and incident STDs. Symptom knowledge was associated with lower prevalence, but not incidence. Beliefs in the efficacy of risk reductions showed a protective effect against incident STDs. Perceived exposure risk and symptom knowledge were associated with risk reduction behavior.

Adolescent↗
PubMed1998

The human glucosamine-6-phosphate deaminase gene: cDNA cloning and expression, genomic organization and chromosomal localization.

When mammalian eggs are fertilized by sperm, a distinct series of calcium oscillations are generated which serve as the essential trigger for egg activation and early embryo development. The identification of a soluble hamster sperm 33-kDa protein that co-migrated with calcium oscillation-inducing activity was recently described by Parrington et al. (Parrington, J., Swann, K., Shevchenko, V.I., Sesay, A.K. and Lai, F.A., 1996. Calcium oscillations in mammalian eggs triggered by a soluble sperm protein. Nature 379, 364-368). The hamster sperm 33 kDa protein was termed oscillin because it correlated with calcium oscillation-inducing activity in mammalian eggs. Sequence analysis of the hamster sperm 33 kDa protein indicated no similarity to any known cell signalling molecule, however, it displayed extensive homology with a bacterial glucosamine-6-phosphate deaminase. We have isolated the corresponding human testis homologue of the hamster sperm 33 kDa cDNA. Nucleotide sequence analysis reveals a high level of sequence identity between the hamster and human genes. The deduced protein sequence of the human gene also shares extensive amino acid identity with the bacterial glucosamine-6-phosphate deaminase enzyme. Heterologous expression of the human testis 33 kDa protein produced a glucosamine-6-phosphate deaminase activity. The genomic structure of the human glucosamine-6-phosphate deaminase has been mapped and the gene was localized by fluorescence in situ hybridization (FISH) to chromosome 5q31.

Aldose-Ketose Isomerases↗
PubMed1998

Calcium oscillations, sperm factors and egg activation at fertilisation.

When an egg is fertilised by sperm, the first intracellular signalling event observed is a large transient increase in cytoplasmic free Ca2+ ions. Elevated Ca2+ is known to play a vital role as an intracellular messenger in all cells and the Ca2+ signal occurring in the egg at fertilisation triggers the subsequent events that mediate early embryo development. In mammalian eggs, the Ca2+ response is first observed as a Ca2+ wave that initiates near the point of sperm-egg fusion, spreads across the entire egg, and then continues as a series of intracellular Ca2+ oscillations. The way in which the fertilising sperm generates the Ca2+ response in the egg has been the subject of much debate over recent years. One proposal for which there is growing evidence suggests the mechanism of egg activation at fertilisation involves the introduction of a soluble sperm protein into the egg shortly after sperm-egg fusion.

Animals↗
PubMed1976

Adding a Medex to the medical mix: an evaluation.

Three classes of Medex were followed during their preceptorship training and subsequent employment to assess the impact of adding such physician assistants on 13 private practices. The data suggest that the Medex are readily incorporated into the practice, seeing a similar spectrum of patients and generally functioning as a semicolleague. Although the Medex was almost universally a contributing addition to the practice, increasing patient volume, the specific effects varied with the setting.

Adolescent↗
PubMed1976

Electrical parameters of the isolated cornea of the dogfish, Squalus acanthias.

The electrical potential difference and electrical resistance of the nonswelling cornea of the dogfish, Squalus acanthias, were examined. It was found that routine procedures used in the procurement of fish invariably produce damage to the corneal epithelium which affects electrical measurements and possibly composition of the aqueous humor. We found no electrical evidence of ionic pumps in the corneal epithelium of this elasmobranch. The electrical resistance of corneas with apparently well-preserved epithelium was 300omega-cm.2 (compared to 30omega-cm.2 in corneas with damaged epithelium).

Animals↗