A method for the identification of pseudorabies virus protein and angiotensin AT(1A) receptor mRNA expression in the same CNS neurons.

Neurotropic viruses have been used over the last 10 years to map the distribution of chains of synaptically connected neurons in the CNS. The peptide content of infected neurons has been determined in a number of cases immunohistochemically. However, it has been unclear whether specific mRNA can be assessed in virus-infected neurons. We have established a technique which enables the identification of viral protein and mRNA in the same neuron. In the present study pseudorabies virus retrogradely transported from the kidney was localised using immunohistochemistry and mRNA for the angiotensin II AT(1A) receptor was detected by hybridisation histochemistry. Virus protein was visualised using an immunohistochemical procedure with diaminobenzidine as the chromogen and the same sections were exposed to radioactively labelled ((35)S) riboprobes, hybridising the angiotensin II AT(1A) receptor. The combination of these two approaches resulted in the identification of neurons shown to project polysynaptically to the kidney and express AT(1A) mRNA. These data provide neuroanatomical support for previous physiological observations that ablation of the lamina terminalis and administration of losartan, the AT(1) receptor antagonist, blocks the inhibition of renal sympathetic nerve activity following centrally injected Ang II in rats and sheep [5].

Activation of kidney-directed neurons in the lamina terminalis by alterations in body fluid balance.

This study was undertaken to determine if neurons in the lamina terminalis, previously identified as projecting to the kidney (35), were responsive to alterations in stimuli associated with fluid balance homeostasis. Neurons in the lamina terminalis projecting to the kidney were identified by the retrograde transynaptic transport of Bartha's strain of pseudorabies virus in anesthetized rats. Rats were also exposed to 24-h water deprivation, intravenous hypertonic saline, or intracerebroventricular ANG II. To determine if "kidney-directed" neurons were activated following each stimulus, brain sections that included the lamina terminalis were examined immunohistochemically for viral antigen and Fos protein. With the exception of ANG II in the subfornical organ, all regions of the lamina terminalis contained neurons that were significantly activated by water deprivation, hypertonic saline, and ANG II. These results provide evidence for a neural substrate, which may underpin some of the effects of hypertonic saline and ANG II on renal function thought to be mediated through the lamina terminalis.

Neurons in the lamina terminalis which project polysynaptically to the kidney express angiotensin AT1A receptor.

The retrograde transynaptic transport of pseudorabies virus was used in conjunction with hybridisation histochemistry for the angiotensin II AT1A receptor, to characterise neurons in the lamina terminalis projecting to the kidney. These data demonstrate that some neurons in the lamina terminalis, that project polysynaptically to the kidney, may be responsive to angiotensin II.

Influence of a counteradvertising media campaign on initiation of smoking: the Florida "truth" campaign.

OBJECTIVES: The purpose of this study was to assess the short-term effects of television advertisements from the Florida "truth" campaign on rates of smoking initiation. METHODS: A follow-up survey of young people aged 12 to 17 years (n = 1820) interviewed during the first 6 months of the advertising campaign was conducted. Logistic regression analyses were used to estimate the independent effects of the campaign on smoking initiation while other factors were controlled for. RESULTS: Youths scoring at intermediate and high levels on a media effect index were less likely to initiate smoking than youths who could not confirm awareness of television advertisements. Adjusted odds ratios between the media index and measures of initiation were similar within categories of age, sex, susceptibility, and whether a parent smoked. CONCLUSIONS: Exposure to the "truth" media campaign lowered the risk of youth smoking initiation. However, the analysis did not demonstrate that all such media programs will be effective.

The Florida "truth" anti-tobacco media evaluation: design, first year results, and implications for planning future state media evaluations.

OBJECTIVES: To outline the design and present selected findings from the evaluation of a state counter-advertising, anti-tobacco media campaign. The appropriateness of the design for states developing media evaluations is discussed. DESIGN: Four cross sectional, telephone surveys of the 12--17 year old population were used to track and monitor advertising and campaign awareness, confirmed awareness, and receptivity. The Florida baseline and one year surveys were used with two parallel national surveys in a quasi-experimental design to assess attitude and smoking related behaviour change attributable to the campaign. MEASURES: Awareness was measured by self report, confirmed awareness by unaided description, and receptivity by self reports of how well advertisements were liked, talked to friends about, and made one think about whether or not to smoke. Eleven attitude and three smoking behaviour items for Florida (treatment) and a national (control) population were compared at baseline and after 12 months. RESULTS: Significant increases in ad specific awareness, confirmed, receptivity, and campaign awareness, and confirmed awareness were reached by the sixth week. They continued to rise through the first year. No attitude and only minor behaviour differences were noted between the treatment and comparison populations at baseline. By the end of the first year, Florida youth had stronger anti-tobacco attitudes and better behaviour patterns than the comparison population. CONCLUSIONS: The industry manipulation strategy used in the Florida campaign resulted in high rates of recall, significant changes in attitudes/beliefs, and reduced rates of smoking behaviour among youth.

Apnoea of prematurity and arousal from sleep.

The incidence of sudden infant death syndrome (SIDS) has been found to be consistently higher in preterm and low birth weight infants than in infants born at term and this increase is inversely related to gestational age. The incidence and severity of apnoea of prematurity, are also inversely related to gestational age. The aim of this study was to investigate whether a neonatal history of apnoea/bradycardia affected the maturation of arousal responses. Twenty-five premature infants were studied. A perinatal risk score was determined for each infant and infants were divided into those with a neonatal history of apnoea/bradycardia (n=16) and those without (n=9). All infants were studied using daytime polysomnography on three occasions: (a) a preterm study around 36 weeks gestation, (b) within 3 weeks of term, and (c) 2-3 months post-term. Multiple measurements of arousal threshold (cm H2O) in response to air-jet stimulation applied alternately to the nares were made in both active sleep (AS) and quiet sleep (QS). Arousal thresholds were elevated in apnoeic infants compared to control infants in both AS (P<0.05) and QS (P<0.001) at the term study and in QS at 2-3 months post-term (P<0.01). In addition, arousal thresholds were positively correlated with perinatal risk score in both sleep states, in all studies, with the exception of AS at 2-3 months when all infants were readily arouseable. We conclude that a history of prematurity with neonatal apnoea has a persisting effect on decreasing arousabilty from sleep and these infants may be at increased risk for SIDS.

Neural pathways from the lamina terminalis influencing cardiovascular and body fluid homeostasis.

1. The lamina terminalis, a region of the brain with a high concentration of angiotensin AT1 receptors, consists of three distinct nuclei, the median preoptic nucleus, the subfornical organ and organum vasculosum of the lamina terminalis (OVLT). These latter two regions lack a blood-brain and detect changes in plasma angiotensin (Ang) II concentration and osmolality. 2. Efferent neural pathways from the lamina terminalis to the hypothalamic paraventricular and supraoptic nuclei mediate vasopressin secretion in response to plasma hypertonicity and increased circulating levels of AngII. 3. Studies using the neurotropic virus pseudorabies, which undergoes retrograde transynaptic neuronal transport following injection into peripheral sites, show that neurons in the lamina terminalis have efferent polysynaptic neural connections to the peripheral sympathetic nervous system. Some of these neurons have been shown to have polysynaptic connections to the kidney and to express AT1 receptor mRNA. We propose that circulating AngII acts at AT1 receptors in the subfornical organ and OVLT to influence the sympathetic nervous system. It is likely that the neural pathway subserving this influence involves a synapse in the hypothalamic paraventricular nucleus. 4. The lamina terminalis may exert an inhibitory osmoregulatory influence on renin secretion by the kidney. This osmoregulatory influence may be mediated by inhibition of renal sympathetic nerve activity and appears to involve a central angiotensinergic synapse. 5. The lamina terminalis exerts an osmoregulatory influence on renal sodium excretion that is independent of the renal nerves and is probably hormonally mediated.

HIV transmission risks of females and males in paired partner relationships.

As the HIV/AIDS epidemic has evolved, heterosexual behaviors have come to be an increasingly important mode of transmission and rates of infection have increased faster among women generally and minority women in particular. Most of what we known about heterosexual risk taking is based on survey data collected from either women or men. These data have been useful for helping to understand different levels and types of risk taking by women and men. However, they provide little information about the levels of risk taking that exist for paired partners in main partner relationships, the types of risks each partner brings to the relationship and how the contribution of partner risks varies. Using data from the pretest of a pilot project designed to test a behavioral intervention to reduce HIV/AIDS transmission among main sex partners, the authors developed four subscales of sexual risk taking for each partner. The association between subscales within and between genders are examined and the subscales are combined to obtain measures of couple risks. Particular attention is given to the gender contribution of partners to couple risk and the differential contribution of types of risk to total risk. The data suggest that, even though men bring relatively higher risks to their main partner relationship than women, this varies inversely with the level of couple risk.

Florida's "truth" campaign: a counter-marketing, anti-tobacco media campaign.

The "truth" campaign was created to change youth attitudes about tobacco and to reduce teen tobacco use throughout Florida by using youth-driven advertising, public relations, and advocacy. Results of the campaign include a 92 percent brand awareness rate among teens, a 15 percent rise in teens who agree with key attitudinal statements about smoking, a 19.4 percent decline in smoking among middle school students, and a 8.0 percent decline among high school students. States committed to results-oriented youth anti-tobacco campaigns should look to Florida's "truth" campaign as a model that effectively places youth at the helm of anti-tobacco efforts.

The industry manipulation attitudes of smokers and nonsmokers.

A cross-sectional random sample was obtained of Florida youth between the ages of 12-17. Data were collected through a telephone survey after obtaining parent and child consent. Industry manipulation attitudes of three groups (self-identified nonsmokers who did not use cigarettes in the past 30 days, self-identified nonsmokers who used cigarettes in the past 30 days, and self-identified smokers who used cigarettes in the past 30 days) were compared. Constraints resulting from the method of data collection resulted in a conservative estimate of the strength of the association between industry manipulation attitudes and smoking behavior.

Relationship dynamics, ethnicity and condom use among low-income women.

CONTEXT: Women's protection against HIV and sexually transmitted diseases (STDs) depends upon their ability to negotiate safer sex. It is important to know how cultural norms and gender roles, which vary by ethnicity, may either constrain or encourage negotiation of condom use. METHODS: Questionnaires were completed by 393 low-income non-Hispanic black, Hispanic and non-Hispanic white women who were sexually active and attending family planning and STD clinics and other public health and social service centers in Miami in 1994 and 1995. Multivariate logit techniques were used to identify ethnic differences in relationship dynamics and to determine couple- and individual-level factors associated with consistent use, occasional use or nonuse of condoms. RESULTS: Black and Hispanic women reported higher levels of consistent condom use (15-17%) than did white women (4%). Nearly all black and white women (90-95%) said that they were extremely or somewhat comfortable talking about condoms with their partner, whereas 76% of Hispanic women did so. A larger proportion of Hispanic women (55%) reported joint contraceptive decision-making than did black women (26%) or white women (31%). Among women who reported that their partner made contraceptive decisions, 28% used condoms consistently or occasionally, compared with 24% among women who made the decision themselves. When the couple made the decision jointly, 41% of them were condom users. Hispanic women scored the lowest on a scale of condom-related self-efficacy, yet also reported the highest levels of confidence in their condom negotiating skills. Multivariate analysis indicated that, compared with white women, black and Hispanic women were more likely to be consistent condom users than nonusers (odds ratios, 10.2 and 18.9, respectively). Women who shared financial decision-making with their partner were almost 80% less likely to be a consistent condom user, and women who did not participate in financial decisions were more than 90% less likely to do so, than were women who made monetary decisions independently. CONCLUSIONS: HIV prevention and intervention programs should emphasize birth control discussion between partners and the development of condom-related self-efficacy and negotiation skills, and these programs also should customize prevention messages according to ethnicity and social context.

Effects of prematurity on arousal from sleep in the newborn infant.

The incidence of sudden infant death syndrome has been found to be consistently higher in preterm and low birth weight infants than in infants born at term. Failure to arouse from sleep is one possible mechanism for sudden infant death syndrome. This study compared the arousal responses to nasal air-jet stimulation in a longitudinal study between groups of healthy preterm and term infants. Preterm infants (n = 9) were born at 31-35 wk gestation with normal birth weights for gestational age and studied on three occasions: a preterm study at 36 wk, at 2-3 wk post-term, and at 2-3 mo post-term. Term infants (n = 22) were born at 37-42 wk and were studied at 2-3 wk and 2-3 mo post-term. Arousal thresholds were determined in both active sleep (AS) and quiet sleep (QS). In preterm infants, there was no state-related difference in arousal thresholds at either the 36 wk or 2-3 wk study; however, at 2-3 mo, arousal threshold was significantly greater in QS than AS (p < 0.05). In contrast, in term infants, arousal thresholds were significantly elevated in QS compared with AS at both 2-3 wk and 2-3 mo (p < 0.001). Arousal thresholds in AS were not different between the two groups of infants, with both groups of infants remaining readily arousable. However, in QS at 2-3 mo, arousal thresholds were significantly lower in the preterm infants (p < 0.05). This study has demonstrated that arousability is altered by gestational and postnatal age. The lower arousability that characterizes QS in term infants regardless of age is not evident in preterm infants until 2-3 mo post-term age.

Identification of neural projections from the forebrain to the kidney, using the virus pseudorabies.

These data demonstrate a chain of synaptically connected neurons extending to the rat kidney through several levels of the neuraxis from the forebrain, and the lamina terminalis -- an area known to be involved in the regulation of body fluid homeostasis. The Bartha strain of pseudorabies virus was injected into the kidney of male Sprague-Dawley rats, resulting in retrograde infections in spinal cord segments (T1-T8), and successive infection in five autonomic 'premotor' areas of the brain, the rostroventrolateral medulla, rostroventromedial medulla, raphe nuclei, A5 region of the pons, and the paraventricular nucleus of the hypothalamus, as well as the nucleus of the solitary tract, locus coeruleus, and subcoeruleus nuclei. Higher order labelling was found in regions of the forebrain, including the organum vasculosum of the lamina terminalis, median preoptic nucleus, subfornical organ, medial preoptic area, bed nucleus of the stria terminalis, anteroventral periventricular nucleus, lateral preoptic area, suprachiasmatic nucleus, retrochiasmatic nucleus, primary motor cortex, and visceral cortex. This polysynaptic pathway to the kidney may form the substrate underlying the impact of forebrain structures on renal function.

Dual-method use among an ethnically diverse group of women at risk of HIV infection.

CONTEXT: Few U.S. women protect themselves against both pregnancy and sexually transmitted diseases (STDs) by using an efficient contraceptive method and a condom. Understanding the factors that influence dual-method use could help improve interventions aimed at encouraging protective behaviors. METHODS: Interviews were conducted with 552 low-income women at risk of HIV who attended public health or economic assistance facilities in Miami in 1994 and 1995. Multinomial logit analyses were used to determine the influence of women's background characteristics, perceived vulnerability to pregnancy and AIDS, and relationship characteristics on the odds of dual-method use. RESULTS: Overall, 20% of the women used dual methods. Women who were not married, who worried about both pregnancy and AIDS, who had ever had an STD, who were confident they could refuse a sexual encounter in the absence of a condom and who made family planning decisions jointly with their partner were the most likely to use dual methods rather than a single method (odds ratios, 2.0-3.5); those who considered the condom only somewhat effective in preventing AIDS or who shared economic decision-making with their partner were the least likely to use dual methods rather than a single method (0.5-0.6). The results were generally similar in analyses examining the odds of dual-method use involving an efficient contraceptive, except that black and Hispanic women were significantly more likely than whites to use condoms in conjunction with efficient contraceptives (3.3-7.1). CONCLUSIONS: Both women's individual characteristics and the context of their sexual relationships influence whether they simultaneously protect themselves from pregnancy and HIV. The involvement of male partners in family planning decision-making and women's control over economic decision-making ensure greater protection against HIV infection.

PIP: Promotion of condom use among women who use efficient contraception is essential to protect them from sexually transmitted diseases (STDs), including HIV, as well as pregnancy. However, fear of negative reactions from a male partner may prohibit dual method use among women who are economically dependent on men. To understand the factors that influence dual method use, interviews were conducted with 522 low-income US women at risk of HIV who attended 21 public health, family planning (FP), and STD clinics or economic assistance centers in Miami, Florida (US), in 1994-95. 54% were concerned about both pregnancy and AIDS; 32% were worried about AIDS only and 5% about pregnancy only. 20% of respondents reported dual method use; overall, 36% of women used condoms (either alone or along with another method). The rate of dual method use was 16% among Whites, 24% among Blacks, and 21% among Hispanics. The likelihood of dual method use was significantly enhanced (odds ratio, 2.0-3.5) among women who were not married, worried about both pregnancy and AIDS, had ever had an STD, were confident they could refuse sex with a man who would not use a condom, and made FP decisions jointly with their partner. Women who regarded condoms as only somewhat effective in preventing HIV infection or who shared economic decision-making with their partner rather than making such decisions alone were least likely to use dual methods. Black and Hispanic women were significantly more likely than White women to use condoms in conjunction with efficient contraception.

Ethnic differences in sexual decisions and sexual behavior.

Previous investigators have reported ethnic differences in the expression of sexual decision making and sexual behaviors in women. In a sample of women of low socioeconomic status between ages 18 and 45, we examined the influence of ethnicity and other variables (age, education, marital status, and comfort in discussing sex) on (i) who makes decisions on the timing and type of sex, (ii) whether a woman engages in vaginal, oral, and anal sex, (iii) the frequencies of each type of sex, and (iv) whether or not a woman has multiple partners. Multivariate analyses showed that, independent of other independent variables, ethnicity had little direct effect on most variables. The notable exception was that ethnicity influenced joint decision making regarding the timing and type of sexual activities for Hispanic but not for African American women. We conclude that ethnicity contributes to differences in sexual behaviors but that other variables are equally important.

Magic Johnson and children's conceptions of AIDS.

Longitudinal data for a heterogeneous sample of 609 elementary school children are used to assess the long-term effects of Magic Johnson's announcement on children's HIV and AIDS conceptions. Four hypotheses are tested concerning these relationships, and background variables measured prior to Johnson's announcement are controlled. Findings suggest that Johnson's announcement increased children's HIV and AIDS knowledge and reduced their prejudice toward a hypothetical child with AIDS. No relationship is evident between the announcement and perceived vulnerability to HIV and AIDS. Males are more likely to be aware of Johnson's announcement, but its effects are more pronounced among blacks. Findings from the present research affirm the potential for celebrities like Johnson in HIV and AIDS education campaigns directed toward children.

Factors associated with use of the female condom.

Black, Hispanic and white women recruited for an HIV prevention intervention were instructed in the use of the female condom and encouraged to try the device. Of the 231 women who completed the intervention, 29% tried the condom over the course of a month; 30% of those who tried it used it during at least half of their sexual encounters. Both ethnicity and age were associated with trying the device: Nearly 40% of black women and 30% of Hispanic women did so, compared with 18% of white women; 37% of those aged 25-34 tried the female condom, compared with 22% of women younger than 25. Trying the device was more likely among women living with a partner, those with a history of sexually transmitted disease infection, women who had had an HIV test, those who did not believe that the method afforded them a greater degree of overall control than did the male condom and those who had no prior knowledge of the device. Among women who used the device during at least half of their sexual encounters, 27% were black and 44% were Hispanic: 38% were younger than 25, and 43% were single. More regular users were about half as likely as less regular users to experience difficulty with insertion and one-eighth as likely to report the device slipping during use; they were more likely than less regular users to report that sex was more pleasurable with the female condom than with the male condom.

PIP: As part of a project to test a behavioral intervention for women at risk of human immunodeficiency virus (HIV), women recruited from sexually transmitted disease clinics, family planning clinics, and state economic service centers in Miami, Florida (US), during 1994-95 were offered free supplies of the female condom. 66 of 231 program participants (29%) tried the female condom; 20 (30%) used it for more than half of their sexual encounters in a 1-month period. Both ethnicity and age were associated with acceptance of female condoms. 40% of Black women, 30% of Hispanic women, and 18% of White women tried the female condom; 37% of those 25-34 years old compared with 22% of women younger than 25 years used the device. Among women who used the female condom for more than half their sexual encounters, 27% were Black and 44% were Hispanic; 38% were under 25 years old and 43% were single. 47% of users had a positive response to the method at first use; after 1 month of use, this rate rose to 75%. 85% of women felt more in control of disease protection for themselves when using the female condom than the male condom. Finally, regular users were about half as likely as irregular users to experience difficulty with condom insertion and more likely to report that sex was more pleasurable with the female condom than the male condom. These findings suggest the female condom could be an important element in HIV prevention campaigns, especially those targeted to Black and Hispanic women, and that method satisfaction increases with regular use.

Children's AIDS-related knowledge and attitudes: variations by grade, race, gender, socioeconomic status, and size of community.

Variations of AIDS-related beliefs by grade, race, gender, socioeconomic status, and size of the community were examined for a diverse group of elementary school children (n = 609). Consistent with prior research, beliefs about HIV transmission and willingness to interact with persons with AIDS increased across grades 1 to 5. Black children living in rural communities held most misconceptions about AIDS and, relative to white peers, black children were more reluctant to interact with persons with AIDS (PWA). Support for more negative attitudes toward PWA among boys was also found. Knowledge of transmission mediated grade and sex differences in willingness to interact, but not race differences. Implications of results for AIDS prevention programs are discussed, along with directions for future research.

The association between substance use, condom use and sexual risk among low-income women.

Substance use is frequently assumed to be associated with higher levels of sexual risk-taking and lower levels of condom use. An analysis of 668 black, Hispanic and white low-income women at public health and public assistance facilities in Miami show that 19% engaged in risky sexual behavior over the preceding six months, 24% in substance use and 31% in condom use. Overall, substance users are nearly four and one-half times more likely to take sexual risks than nonusers, but are about half as likely to have relied on condoms. When the probability of condom use is considered in the context of both substance use and sexual risk, substance users who take sexual risks appear just as likely to rely on condoms as are nonusers who take sexual risks and those who do not (odds of 0.43-0.49). However, substance users who do not take sexual risks are much less likely to use condoms (odds of 0.15). This pattern holds among black, Hispanic and white women, and suggests that perceptions of risk and the risks that partners bring to sexual encounters may be more important determinants of condom use than substance use per se.

PIP: 668 Black, White, and Hispanic low-income women at 21 public health, sexually transmitted disease (STD), and family planning clinics or state economic service centers in Miami provided data on their sex behavior, drug and alcohol consumption, and condom use. The data were collected from September 1994 through February 1995. Any participant who reported having had sex with three or more partners in the preceding 6 months, exchanging sex for drugs or money in the preceding 6 months, or having a sex partner who they believe has had sex with men or had injected drugs was classified as a sexual risk-taker. Any woman who had taken any recreational drugs in the past 6 months or had drank alcohol before having sex over the same period was classified as a substance user. 19% of the women engaged in risky sex behavior over the preceding 6 months, 24% in substance use, and 31% in condom use. Overall, the substance users are almost 4.5 times more likely to take sexual risks than nonusers, and about half as likely to have used condoms. Substance users who take sexual risks seem just as likely to use condoms as nonusers who take sexual risks and those who do not. However, substance users who do not take sexual risks are far less likely to use condoms. This pattern holds among Black, White, and Hispanic women, and suggests that perceptions of risk and the risks that partners bring to sexual encounters may be more important determinants of condom use than substance use alone.

Central reorganization of sensory pathways following peripheral nerve regeneration in fetal monkeys.

Transection of a sensory nerve in adults results in profound abnormalities in sensory perception, even if the severed nerve is surgically repaired to facilitate accurate nerve regeneration. In marked contrast, fewer perceptual errors follow nerve transection and surgical repair in children. The basis for this superior recovery in children was unknown. Here we show that there is little or no topographic order in the median nerve to the hand after median nerve section and surgical repair in immature macaque monkeys. Remarkably, however, in the same animals the representation of the reinnervated hand in primary somatosensory cortex area (area 3b) is quite orderly. This indicates that there are mechanisms in the developing brain that can create cortical topography, despite disordered sensory inputs. Presumably the superior recovery of perceptual abilities after peripheral nerve transection in children depends on this restoration of somatotopy in the central sensory maps.