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Stuart Brody

Publications and source records attributed to Stuart Brody.

At least 19 recordsLinked to original sources
PubMed2006

Lack of autodisable syringe use and health care indicators are associated with high HIV prevalence: an international ecologic analysis.

PURPOSE: A growing body of evidence strongly suggests that unsafe health care is an important factor driving the human immunodeficiency virus (HIV) epidemic in sub-Saharan Africa. We investigate whether nonuse of autodisable syringes and other health care indicators predict national HIV prevalence. METHODS: These ecologic analyses use countries as study units in descriptive analyses and regression analyses. Two sets of observations are used: (i) all low- and lower-middle-income countries, and (ii) all sub-Saharan African countries with available data. RESULTS: In the descriptive analysis, health care indicators (health expenditures, vaccination coverage, and use of autodisable syringes) have a U-shaped relationship with HIV prevalence in the larger sample. Greater density of physicians is associated with lower HIV prevalence. In sub-Saharan Africa, antenatal care coverage is associated with increasing HIV prevalence. In regression analyses, nonuse of autodisable syringes is associated robustly with greater HIV prevalence in all models. For the larger sample, greater HIV prevalence also is associated with higher Gini Index, less female economic activity, less urbanization, and less percentage of Muslims. In sub-Saharan Africa, tetanus vaccination coverage has a U-shaped association with HIV prevalence. Low physician density and percentage of Muslims are associated with HIV prevalence. Other economic and health care indicators and epidemic age are not significant correlates of HIV prevalence. CONCLUSIONS: This analysis adds to the other sources of evidence for health care transmission of HIV (in sub-Saharan Africa and regions with similar epidemiologic characteristics) by showing that health care indicators (failure to use autodisable syringes and greater tetanus coverage) are associated robustly with greater HIV prevalence. We recommend that resources be reallocated to address health care transmission of HIV/acquired immunodeficiency syndrome.

Africa South of the Sahara↗
PubMed2006

The role of health care in the spread of HIV/AIDS in Africa: evidence from Kenya.

It is commonly asserted that the sub-Saharan African HIV/AIDS epidemic is predominantly due to heterosexual transmission. However, recent re-examination of the available evidence strongly suggests that unsafe health care is the more likely vector. The present report adds to the evidence for health-care transmission by showing that Kenyan women who received prophylactic tetanus toxoid injections during pregnancy are 1.89 times (95% confidence interval [CI]:1.03-3.47) more likely to be HIV-1 seropositive than women who did not receive this vaccination. In contrast, recent sexual behaviour (condom use, number of partners) was not related to HIV status. The findings are unconfounded by reverse causality (all injections were purely prophylactic rather than for treatment of any HIV-related illnesses, and none of the women reported knowing that she was HIV seropositive). Focus on a specific injection may have improved participant recall. The results are consistent with health care being a very important vector for HIV in sub-Saharan Africa. It is recommended that there be a reallocation of resources to address healthcare transmission of HIV/AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Circadian rhythms in Neurospora crassa: clock gene homologues in fungi.

Computer-based analysis of a total of 17 filamentous fungal and yeasts genomes has shown: (1) homologues of frq, wc-1, wc-2, and vvd, key gene components of the Neurospora crassa clock, are present in Magnaporthe grisea, Gibberella zeae, and Podospora anserina, suggesting an frq-based oscillator in these organisms; (2) some fungal species that are more distantly related to Neurospora, such as Rhizopus oryzae do not appear to have frq homologues; (3) many fungal species that do not appear to contain frq, such as Aspergillus nidulans, do contain wc homologues; (4) of 11 well-described genes classified as clock-controlled genes (ccgs), in Neurospora, all of them were found to have homologues in other fungi; (5) the ccg-8 gene of N. crassa has homologies to opi1p, a transcriptional regulatory gene in Saccharomyces cerevisiae involved in inositol regulation. This suggests the possibilities of rhythmic inositol regulation, and/or a cascade of rhythmic activation of other genes in N. crassa.

Biological Clocks↗
PubMed2005

The post-orgasmic prolactin increase following intercourse is greater than following masturbation and suggests greater satiety.

Research indicates that prolactin increases following orgasm are involved in a feedback loop that serves to decrease arousal through inhibitory central dopaminergic and probably peripheral processes. The magnitude of post-orgasmic prolactin increase is thus a neurohormonal index of sexual satiety. Using data from three studies of men and women engaging in masturbation or penile-vaginal intercourse to orgasm in the laboratory, we report that for both sexes (adjusted for prolactin changes in a non-sexual control condition), the magnitude of prolactin increase following intercourse is 400% greater than that following masturbation. The results are interpreted as an indication of intercourse being more physiologically satisfying than masturbation, and discussed in light of prior research reporting greater physiological and psychological benefits associated with coitus than with any other sexual activities.

Adult↗
PubMed2005

Blood pressure reactivity to stress is better for people who recently had penile-vaginal intercourse than for people who had other or no sexual activity.

Penile-vaginal intercourse (PVI) but not other sexual behavior is associated with better psychological and physiological function. I examined the relationship of sexual behavior patterns to blood pressure (BP) and its reactivity to stress (public speaking and verbal arithmetic). For a fortnight, 24 women and 22 men used daily diaries to record PVI, masturbation, and partnered sexual behavior in the absence of PVI. Persons who reported PVI (but no other sexual activities) had better stress response (less reactivity and/or lower baseline levels) than persons reporting other or no sexual behaviors. Persons who only masturbated or had partnered sex without PVI had 14 mmHg more systolic BP reactivity than those who had PVI but not the other behaviors. Many variables were examined but failed to confound the observed relationships. The magnitude of the sexual behavior effect on BP reactivity is greater than of other factors in the literature. These findings add to the research corpus on the benefits of PVI (differentiated from other sexual activities).

Blood Pressure↗
PubMed2004

Mortality in a long-term open cohort of prostitute women.

In this study, the authors estimated overall and cause-specific mortality among prostitute women. They recorded information on prostitute women identified by police and health department surveillance in Colorado Springs, Colorado, from 1967 to 1999. The authors assessed cause-specific mortality in this open cohort of 1,969 women using the Social Security Death Index and the National Death Index, augmented by individual investigations. They identified 117 definite or probable deaths and had sufficient information on 100 to calculate a crude mortality rate (CMR) of 391 per 100,000 (95% confidence interval (CI): 314, 471). In comparison with the general population, the standardized mortality ratio (SMR), adjusted for age and race, was 1.9 (95% CI: 1.5, 2.3). For the period of presumed active prostitution only, the CMR was 459 per 100,000 (95% CI: 246, 695) and the SMR was 5.9 (95% CI: 3.2, 9.0). Violence and drug use were the predominant causes of death, both during periods of prostitution and during the whole observation period. The CMR for death by homicide among active prostitutes was 229 per 100,000 (95% CI: 79, 378), and the SMR was 17.7 (95% CI: 6.2, 29.3). Deaths from acquired immunodeficiency syndrome occurred exclusively among prostitutes who admitted to injecting drug use or were inferred to have a history of it.

Adult↗
PubMed2004

Selective processing of food words during insulin-induced hypoglycemia in healthy humans.

RATIONALE: Hypoglycemia leads to undernutrition of the brain. Favoring selective processing of food stimuli would be an adaptive cognitive strategy. However, hypoglycemia is known to impair several aspects of cognitive function, and it is unknown whether selective cognitive processing of food stimuli occurs during insulin-induced hypoglycemia. METHODS: In a single-blind repeated measures design, healthy young adults (n=12, six female, mean age 28 years; mean body mass index 22.5 kg/m(2)) performed a standard Stroop word-color test, as well as a variant with food words designed to detect selective processing of food cues. Two sessions were scheduled with a 4-week interval. In each session, a hyperinsulinemic clamp method produced a normoglycemic (plasma glucose: 4.7 mmol/l) period, followed on 1 day by a hypoglycemic (2.7 mmol/l) testing period, and on the other day a second normoglycemic testing period (counterbalanced order). RESULTS: Color naming verbal reaction time (RT) increased during hypoglycemia (P<0.0001). The extent of the Stroop cognitive interference was independent of plasma glucose level. The key finding is that RT for food words increased more than for non-food control words (P<0.004), and this effect was not predicted by hunger ratings. CONCLUSIONS: Our data provide new evidence that during hypoglycemia, attention is directed selectively to food-relevant stimuli. The results are discussed in terms of adaptation.

Adaptation, Physiological↗
PubMed2004

Mental relaxation improves long-term incidental visual memory.

Experimental evidence has linked increased arousal to enhanced memory retention. There is also evidence that procedures reducing arousal, i.e., mental relaxation, might improve memory, but conflicting results have been reported. To clarify this issue, we studied the effects of a single session of relaxation training on incidental visual long-term memory. Thirty-two relaxation-naive subjects viewed 280 slides without being told that there would be subsequent memory testing. Afterwards, subjects listened to a 12 min relaxation tape; 16 subjects relaxed by following the instructions (relaxation group), and the other 16 subjects pressed a button whenever a body part was mentioned (control group). While listening to the relaxation tape, high frequency heart rate variability (HRV) was greater and low frequency HRV was lower in the relaxation group, implying effective relaxation and increasing parasympathetic activation. The relaxation group had superior memory retention 4 weeks later (p = .004), indicating enhancement of long-term memory performance. This effect could not be explained by retroactive interference experienced in the control group because short-term memory performance immediately after the tape was slightly better in the control group. Retention of materials acquired after the relaxation session remained unaffected, suggesting relaxation has retrograde effects on memory consolidation. Our data demonstrate a favorable influence of relaxation on at least this aspect of learning. Our data also extend previous knowledge on the beneficial effects of ascending parasympathetic stimulation on memory retention in that enhanced long-term memory consolidation may also occur in the presence of central and descending parasympathetic activation triggered by willful psychomotor activity.

Adult↗
PubMed2004

Increased high-frequency heart rate variability during insulin-induced hypoglycaemia in healthy humans.

Despite causing sympathetic activation, prolonged hypoglycaemia produces little change in HR (heart rate) in healthy young adults. One explanation could be concurrent parasympathetic activation, resulting in unchanged net effects of autonomic influences. In the present study, hypoglycaemic (2.7 mmol/l) and normoglycaemic (4.7 mmol/l) hyperinsulinaemic clamp studies were performed after normoglycaemic baseline clamp periods with 15 healthy volunteers (seven male; mean age, 27 years) on two occasions in a randomized single-blind cross-over design. Non-invasive indices of cardiac autonomic activity and hormones were measured at baseline and 1 h after the beginning of hypoglycaemia or control normoglycaemia. Plasma insulin levels and mean HR were similar during both conditions. During hypoglycaemia, there was a 485% increase in plasma adrenaline (epinephrine). A shortening of the pre-ejection period by 45% suggested strong sympathetic cardiac activation. High-frequency (0.15-0.45 Hz) HRV (HR variability) increased, indicating a concomitant increase in parasympathetic tone. Thus, during hypoglycaemia-induced sympathetic cardiac activation in healthy adults, parasympathetic mechanisms are involved in stabilizing mean HR.

Adult↗
PubMed2004

Circadian rhythms in microorganisms: new complexities.

Recent advances in understanding circadian (daily) rhythms in the genera Neurospora, Gonyaulax, and Synechococcus are reviewed and new complexities in their circadian systems are described. The previous model, consisting of a unidirectional flow of information from input to oscillator to output, has now expanded to include multiple input pathways, multiple oscillators, multiple outputs; and feedback from oscillator to input and output to oscillator. New posttranscriptional features of the frq/white-collar oscillator (FWC) of Neurospora are described, including protein phosphorylation and degradation, dimerization, and complex formation. Experimental evidence is presented for frq-less oscillator(s) (FLO) downstream of the FWC. Mathematical models of the Neurospora system are also discussed.

Animals↗
PubMed2004

Does selected ecological evidence give a true picture of HIV transmission in Africa?

Current reconsideration of the contributions of various modes of transmission to HIV epidemics in sub-Saharan Africa has important implications for HIV prevention. In recent reviews, we argue that accumulated evidence supports the hypothesis that unsafe health care fuels Africa's HIV epidemics. In response, critics have presented selected ecological evidence - age and sex distribution of HIV infections and geographic distribution of hepatitis C virus infections - to support the conventional hypothesis that sexual contact accounts for most HIV infections. In this communication, we examine critics' evidence and arguments. Critics ignore or reject important evidence including, for example, large numbers of unexplained HIV infections in children, strong associations between incident HIV and injections, and genetically-linked infections in persons with no known sexual contact. We urge that research projects in Africa disclose unpublished relevant evidence on risks for incident HIV. In any case, because each iatrogenic infection causes subsequent linked infections, the impact of HIV transmission through health care has been underestimated. We commend the emerging consensus to improve the safety of health care delivery. In countries with generalized HIV epidemics, we urge public education about the risks for HIV acquisition from unsterile health care.

Africa↗