Comparative study of the effect of muscle relaxants on the intraocular pressure

Control of intraocular pressure is a major concern in ophthalmic anesthesia, especially in the presence of glaucoma or penetrating eye injury. The use of succinylcholine under these conditions is controversial. This study was undertaken to assess the effects of the neuromuscular blocking agents succinylcholine, pancuronium, metocurine, vecuronium, and atracurium on the intraocular pressure of dogs. The study was performed on five "conditioned" mature male foxhounds. The dogs were intubated immediately after induction with thiopental 10 mg/kg and ventilated with an O2/N2O mixture (FIO2 = 0.33). The ventilation was controlled to maintain an endtidal CO2 concentration of 5 vol.%. and anesthesia maintained with a fentanyl infusion of 10 micrograms/kg per hour. Direct and continuous measurements were taken of blood pressure (MAP), central venous pressure (CVP), and intra-ocular pressure (IOP), the latter via a 22-gauge needle inserted into the anterior chamber of the eye. A force-displacement transducer was attached to the hindpaw to monitor muscle twitch following supramaximal stimulation of the anterior tibial nerve. These four measurements were displayed on a multi-channel polygraph (Figs. 1 and 2). Control values were obtained and then succinylcholine 1 mg/kg, pancuronium 0.1 mg/kg, metocurine 0.3 mg/kg, vecuronium 0.1 mg/kg, or atracurium 0.4 mg/kg were given in a randomized fashion and on different days. Measurements of heart rate (HR), MAP, CVP, and IOP were noted at 2, 5, 10, 20, and 30 min after giving the neuromuscular blocking agent. The results, as displayed on the polygraphy, indicate that the least effect on IOP and cardiovascular state followed neuromuscular blockade with vecuronium and atracurium.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sex-Positivity,Medical Mistrust,and PrEP Conspiracy Beliefs Among HIV-Negative Cisgender Black Sexual Minority Men in Atlanta,Georgia

Because the public health response to the disproportionate HIV burden faced by Black sexual minority men (BSMMM) has focused on sexual risk reduction and disease prevention, other vital components of sexual health (e.g., intimacy, pleasure, benefits of sex) have been often overlooked. Sex-positive describes a more open, holistic approach toward sex and sexuality that prioritizes these other components, though such an approach is rarely applied to BSMM's sexual health. For sex-positive BSMM, risk/preventive discourse may foster or exacerbate medical mistrust as a reaction to the dissonance between how these men view sexual health and how the medical establishment views it, which may discourage sexual healthcare-seeking. We assessed sex-positivity and its association with medical mistrust and PrEP conspiracy beliefs among 206 HIV-negative cisgender BSMM in Atlanta, Georgia. We performed exploratory factor analytic procedures on responses to a sex-positivity scale, followed by multivariable linear regressions to determine sex-positivity’s associations with medical mistrust and PrEP conspiracy beliefs. We extracted two sex-positivity factors: sexual freedom (α?=?0.90), reflecting openness toward casual sex and rejection of sexual mores, and essence of sex (α?=?0.77), reflecting the intimate, relational, and pleasurable qualities of sex. Sexual freedom was independently associated with perceived provider deception (β?=?0.19, CI?=?0.04, 0.34). Essence of sex was independently associated with PrEP conspiracy beliefs (β?=?0.16, CI?=?0.02, 0.31) and marginally associated with perceived provider deception (β?=?0.14, CI?=???0.00, 0.29). Healthcare providers and public health practitioners may cultivate greater trust with BSMM by incorporating a sex-positive approach into patient/participant interactions, clinical decision-making, and interventions. Improving access to sexual pleasure acknowledges BSMM’s right to optimal, holistic sexual health.

     

Weibel-Palade bodies in endothelial cells as a marker for angiogenesis in brain tumors

A transmission electron microscope study was made of eight childhood brain tumors divided up into three zones, center, edge, infiltrating zone, and also of adjacent "normal-looking" brain. In seven of eight tumors, the numbers of Weibel-Palade bodies in endothelial cells were significantly increased in peripheral zones compared with central zones. A similar significant increase was observed after treatment of chick chorioallantoic membranes with tumor angiogenesis factor. It is suggested that large numbers of Weibel-Palade bodies may be a marker for proliferating endothelial cells in vivo.     

Causes of re-recurrence after polytetrafluoroethylene patch saphenoplasty for recurrent varicose veins

BACKGROUND: The aim of this study was to determine whether a polytetrafluoroethylene (PTFE) patch sutured over the religated saphenofemoral junction could reduce the rate of recurrence after operation for recurrent varicose veins. METHODS: Fifty patients who had surgery for recurrent long saphenous incompetence (81 legs had a small PTFE patch sutured over the religated saphenofemoral junction. There were no major complications following surgery. Three patients had a wound infection or delayed healing. All patients were invited for clinical examination and duplex imaging at a median of 19 (range 6-39) months after operation. RESULTS: Some 38 of 43 patients (70 legs) remained satisfied with the results of surgery; 16 (23 per cent) of 70 legs had visible veins on inspection and eight of these (11 per cent) involved symptomatic recurrence. Duplex imaging showed that recurrence was due to saphenofemoral junction incompetence in ten legs; two appeared to have a major groin connection but the other eight appeared to have neovascularization. Other causes were thigh perforator reflux (three legs) and cross-groin collaterals (three). Eleven of the 16 legs with recurrence had varicography but in two the procedure was a technical failure. Two legs had evidence of a significant connection (more than 3 mm) and two a minor connection (less than 3 mm) to the femoral vein at the level of the PTFE patch, but in the remainder recurrence was due to upper thigh perforating veins. There was good concordance between duplex imaging and varicography. CONCLUSION: PTFE patch saphenoplasty appears to be safe. Although these are early results, the technique seems potentially as effective as other barrier methods that have been investigated; in ten legs (12 per cent) recurrence was attributed to failure at the level of the PTFE patch.     

A Closer Look at Racism and Heterosexism in Medical Students’ Clinical Decision-Making Related to HIV Pre-Exposure Prophylaxis (PrEP): Implications for PrEP Education

Social biases among healthcare providers could limit PrEP access. In this survey study of 115 US medical students, we examined associations between biases (racism and heterosexism) and PrEP clinical decision-making and explored prior PrEP education as a potential buffer. After viewing a vignette about a PrEP-seeking MSM patient, participants reported anticipated patient behavior (condomless sex, extra-relational sex, and adherence), intention to prescribe PrEP to the patient, biases, and background characteristics. Minimal evidence for racism affecting clinical decision-making emerged. In unadjusted analyses, heterosexism indirectly affected prescribing intention via all anticipated behaviors, tested as parallel mediators. Participants expressing greater heterosexism more strongly anticipated increased risk behavior and adherence problems, which were associated with lower prescribing intention. The indirect effect via condomless sex remained significant adjusting for background characteristics. Prior PrEP education did not buffer any indirect effects. Heterosexism may compromise PrEP provision to MSM and should be addressed in PrEP-related medical education.     

Changes in Experiences With Discrimination Across Pregnancy and Postpartum: Age Differences and Consequences for Mental Health

Objectives. We aimed to contribute to growing research and theory suggesting the importance of examining patterns of change over time and critical life periods to fully understand the effects of discrimination on health, with a focus on the period of pregnancy and postpartum and mental health outcomes.Methods. We used hierarchical linear modeling to examine changes across pregnancy and postpartum in everyday discrimination and the resulting consequences for mental health among predominantly Black and Latina, socioeconomically disadvantaged young women who were receiving prenatal care in New York City.Results. Patterns of change in experiences with discrimination varied according to age. Among the youngest participants, discrimination increased from the second to third trimesters and then decreased to lower than the baseline level by 1 year postpartum; among the oldest participants, discrimination decreased from the second trimester to 6 months postpartum and then returned to the baseline level by 1 year postpartum. Within-subjects changes in discrimination over time predicted changes in depressive and anxiety symptoms at subsequent points. Discrimination more strongly predicted anxiety symptoms among participants reporting food insecurity.Conclusions. Our results support a life course approach to understanding the impact of experiences with discrimination on health and when to intervene.A large and ever-growing body of research has shown that experiences with discrimination are associated with a wide range of adverse mental and physical health outcomes and may help explain socioeconomic and racial/ethnic health disparities in the United States.1,2 Although the majority of this research has been cross-sectional, an increasing number of longitudinal studies have shown that discrimination predicts poorer health.3,4 Some studies have gone further to examine within-person changes over time in discrimination and the resulting health implications.5–7Recently, Gee et al.8 proposed a life course perspective, calling for more research on changes in experiences with discrimination during critical periods to fully understand discrimination’s health effects and inform interventions. We examined changes across pregnancy and 1 year postpartum in experiences with everyday discrimination and consequences in terms of subsequent changes in depressive and anxiety symptoms among predominantly Black and Latina, socioeconomically disadvantaged young women residing in New York City. In their recent theoretical article, Gee et al. asserted:

Exposure to racism can change in nature, importance, and intensity. Similarly, health and the factors that produce health can change. A growing body of research shows that health is not merely the result of risks that occur sporadically at one point in time. Failure to attend to these temporal changes not only shortchanges our knowledge base, but also can lead to missed opportunities for intervention.8^(p967)

Cross-sectional (or even longitudinal) studies examining between-subjects associations of discrimination with health outcomes cannot assess changes in discrimination over time. To advance understanding of the health effects of discrimination, taking a life course perspective and examining changes in discrimination over time are crucial. Gee et al.8 highlighted potential age-patterned exposures to discrimination, with certain critical periods during which changes are more drastic. Some research supports this perspective, with evidence that racial discrimination increases across adolescence5 among African American youths and increases over time6 among African American, Latino, and Asian American youths. Although Gee et al. focused on racism, we suggest that their framework applies to all forms of discrimination.Pregnancy and postpartum may be a critical period to study changes in discrimination, given that women’s experiences with discrimination during pregnancy increase their likelihood of adverse maternal and infant health outcomes such as having a low birth weight infant9,10 and contracting a sexually transmitted infection.11 Also, women experience changes in their bodies, social relationships, and emotions12 during pregnancy and postpartum and come into contact with a variety of new social institutions, including those related to obstetrics and child care; thus, as a result of these life changes, women may experience changes in exposure to discrimination during this time period.8Changes in experiences with discrimination may also vary according to factors such as age, race/ethnicity, nativity, and socioeconomic status. Socioeconomically disadvantaged women, women of color, and women born outside of the United States who may have experienced discrimination regularly throughout their lives might feel that they are treated better or face less discrimination during pregnancy and the postpartum period, when people may extend them courtesies (e.g., giving up a seat on a bus) and institutions may offer added support (e.g., ensuring prenatal and infant care).By contrast, some theories suggest that Black and Latina women in the United States may experience heightened discrimination during pregnancy and postpartum because of group stereotypes related to sexuality and motherhood (e.g., sexual promiscuity, single parenthood) and the societal devaluation of motherhood in women of color.13,14 Some of these negative stereotypes specifically target Black and Latina adolescents and young women14 and so may be particularly relevant for younger age groups. Thus, experiences with discrimination can increase or decrease during pregnancy and postpartum, and the pattern of change may vary on the basis of characteristics such as age, race/ethnicity, nativity, and socioeconomic status. It is therefore important to assess these characteristics as potential moderators of changes in discrimination during this period.Discrimination is an important determinant of mental health across different social groups.1,2 The majority of research on discrimination and mental health is cross sectional; as noted, however, an increasing amount of research has explored this association longitudinally. For example, individual differences in Black Americans’ experiences with racial discrimination have been found to predict depressive and anxiety symptoms at a later time point, but differences in depressive and anxiety symptoms have not been found to predict racial discrimination at a later point.4,15Studies have begun to explore whether experiences with discrimination change over time and whether these changes are associated with changes in mental health. Schulz et al.7 found that changes over 2 time points (spaced 5 years apart) in Black American women’s experiences with discrimination were positively associated with simultaneous changes in depressive symptoms and negatively associated with changes in self-rated health.Greene et al.6 found that changes in experiences with discrimination across 5 time points (over 3 years) were negatively associated with simultaneous changes in self-esteem and positively associated with changes in depressive symptoms among Black, Latino, and Asian American high school students. Similarly, Brody et al.5 found that changes in experiences with racial discrimination across 3 time points (over 5 years) were positively associated with simultaneous changes in conduct problems and depressive symptoms among Black adolescents. To the best of our knowledge, despite this existing research on discrimination and depressive symptoms, no work has examined associations between changes in discrimination and changes in anxiety or assessed these associations during pregnancy.Yet, pregnancy and postpartum may be a particularly important period during which to examine associations of discrimination with depressive and anxiety symptoms. During pregnancy, these symptoms have adverse consequences for birth outcomes (e.g., preterm birth and low birth weight) and infant development (e.g., cognitive and motor development).16 In the postpartum period, these symptoms have adverse consequences with respect to parenting behaviors (e.g., playing with and talking to the infant) and the health of both the mother and the child.17 In addition, although past research suggests that discrimination has adverse mental health consequences across diverse groups, much of this research has focused on specific groups (e.g., Black Americans), and thus it is important to examine whether these associations vary according to factors such as age, race/ethnicity, nativity, and socioeconomic status.The first aim of our study was to examine changes in experiences with discrimination across pregnancy and 1 year postpartum and assess whether age, race/ethnicity, nativity, or socioeconomic status moderated the pattern of change. Our second aim was to explore whether changes in experiences with discrimination over time predicted changes in depressive and anxiety symptoms at subsequent points and whether the sociodemographic factors just described moderated these associations.Given the competing theories described earlier, we did not have a specific expected pattern of change; rather, we hypothesized that experiences with discrimination would change across pregnancy and the postpartum period and that age, race/ethnicity, nativity, or socioeconomic status of participant might moderate that pattern. Also, consistent with past work showing associations between discrimination and mental health across diverse groups, we hypothesized that changes in experiences with discrimination across pregnancy and postpartum would significantly positively predict changes in depressive and anxiety symptoms at subsequent time points and that participants’ age, race/ethnicity, nativity, and socioeconomic status would not moderate those associations.