Activation of a ventral hippocampus-medial prefrontal cortex pathway is both necessary and sufficient for an antidepressant response to ketamine.

A single sub-anesthetic dose of ketamine exerts rapid and sustained antidepressant effects. Here, we examined the role of the ventral hippocampus (vHipp)-medial prefrontal cortex (mPFC) pathway in ketamine's antidepressant response. Inactivation of the vHipp with lidocaine prevented the sustained, but not acute, antidepressant-like effect of ketamine as measured by the forced swim test (FST). Moreover, optogenetic as well as pharmacogenetic specific activation of the vHipp-mPFC pathway using DREADDs (designer receptors exclusively activated by designer drugs) mimicked the antidepressant-like response to ketamine; importantly, this was pathway specific, in that activation of a vHipp to nucleus accumbens circuit did not do this. Furthermore, optogenetic inactivation of the vHipp/mPFC pathway at the time of FST completely reversed ketamine's antidepressant response. In addition, we found that a transient increase in TrkB receptor phosphorylation in the vHipp contributes to ketamine's sustained antidepressant response. These data demonstrate that activity in the vHipp-mPFC pathway is both necessary and sufficient for the antidepressant-like effect of ketamine.

Assessing the application of HIV and AIDS related education and counselling on the Internet.

This study reviewed Internet technological capabilities for counselling and several appropriate counselling models and assessed the application of HIV/AIDS related counselling on the Internet. Sixteen health professionals in HIV/AIDS related face-to-face counselling positions were interviewed: their HIV/AIDS service background was limited to Texas-certified HIV pre/post test counsellors. Texas-licensed counsellors in HIV/AIDS service field and HIV/AIDS case managers and social workers. Duration of interviews ranged from 30 min to 60 min and were recorded on audio cassette for review and analysis. Responses were generated using an editing style of the long-interview process. Edited responses were then analyzed for content and themes. Four major themes evolved from interview responses: counsellor-client relationship, target population, ethics and operation. Major concerns included the lack of visual and verbal cues during interaction, problems of accessibility by the neediest, confidentiality, impersonal experience and increased client separation/isolation. Greater benefits may be attained by targeting the younger segment of the population and other health professionals. A majority of respondents indicated support for additional development of Internet-based HIV/AIDS related counselling.

Predictive value of prior Rose angina for myocardial infarction confirmation after emergency admissions.

The Rose Questionnaire, developed to facilitate screening for the presence of coronary artery disease, has shown good utility for white men and more variable utility among Latino, African-American, and female subjects. This study investigated its utility for prediction of outcome in patients with suspected myocardial infarction. A total of 1428 white, Latino, and African-American subjects completed questionnaires after emergency admission, which were correlated with diagnoses at the time of discharge from a public hospital and private hospital. Results indicated that subjects with positive questionnaires were less likely to have infarction confirmed at discharge, except for those with a prior history of myocardial infarction, than those with a negative response. These data are important in evaluating the overall utility of the Rose Questionnaire and the significance of angina.

Preliminary investigation of the use of dried-blood spots for the assessment of in utero exposure to environmental pollutants.

We determined the concentration of dichlorodiphenyldichloroethylene (p,p'-DDE) in dried-blood spot specimens from 2-day-old infants from rural Texas who had never been breast fed. Anonymous, residual whole blood spots on filter paper, previously used for routine newborn screening procedures, were soaked in a phosphate buffer, extracted with an organic solvent, and eluted through silica gel. The concentrated eluates were analyzed by capillary gas chromatography with electron capture detection (ECD). The blood collected from 10 newborns was analyzed and found to contain DDE concentrations ranging from 0.13 to 1.87 pg/microliter with a mean of 0.72 pg/microliter. One of the 10 newborns had a whole blood DDE concentration of 1.87 pg/microliter, which was greater than the concentration of 1.34 pg/microliter in a freshly drawn sample from an adult donor whose blood serum was shown to contain DDE. With improvement in detection limits, this approach has the potential to displace the analyses of mothers' blood (as a surrogate indicator of infants' exposures) and cord blood as standard procedures for determining the newborns' body burden of environmental pollutants.

Early radionuclide scans for risk assessment in suspected acute myocardial infarction.

First-day thallium-201 myocardial perfusion scans and technetium-99m RBC gated scintiangiography were performed during the initial clinical and prognostic evaluation of 69 patients with suspected acute myocardial infarction. Patients were monitored for clinical course, diagnosis confirmation, and use of specialty services (cardiac catheterization, percutaneous balloon angioplasty, and cardiac surgery) during hospitalization. Myocardial infarction, confirmed in 20 patients, was associated with significantly more left ventricular dilatation, lower ejection fractions, lower peak left ventricular filling rates, wall motion abnormalities, and thallium-201 perfusion defects than nonmyocardial infarction patients. Among all patients, left ventricular dilatation carried a relative risk of myocardial infarction of 5.8; low ejection fraction and right ventricular dilatation were strongly associated with myocardial infarction. A logistic model for congestive heart failure included: left ventricular dilation, lower mean left ventricular filling rates and time to peak filling rates, and abnormal thallium-201 lung:heart uptakes. Among nonmyocardial infarction patients, subsequent cardiac catheterization was predicted by the presence of anterior thallium-201 perfusion defects, Killip functional class II-III, and ischemia on ECG. These findings suggest that early detection of myocardial perfusion defects and cardiac dysfunction by radionuclide scans enhances initial evaluation of suspected acute myocardial infarction patients. Additional studies are needed to confirm these findings.

Differential perceptions, behaviors, and motivations among African Americans, Latinos, and whites suspected of heart attacks in two hospital populations.

To evaluate the hypothesis that socioeconomic status would exert greater influence on patients' care-seeking behavior than racial/ethnic group status, we undertook a sequential study of African-American, Latino, and white patients hospitalized for acute chest pain from August 1988 through July 1990 at two sites. The study took place in an urban public medical center and an urban private health maintenance organization medical center, which provide care to mixed racial/ethnic groups of lower and middle socioeconomic status, respectively, in Los Angeles. Three concurrent case series of African-American, Latino, and white patients hospitalized for acute chest pain were recruited. The racial/ethnic distribution of the total group was African Americans, 448; Latinos, 487; and whites, 499. The main outcome measure was the length of time patients spent in deciding to seek emergency medical care for acute chest pain and the associated perceptions, behaviors, and motivations involved in deciding to seek care. For the total group, public hospital site and lack of health insurance were the strongest significant predictors of a longer decision phase, whereas differential symptom perceptions, consultation with medical professionals, and use of paramedic transport were significant predictors of shorter duration. Multiple regression results were similar in separate analyses demonstrated significant differences in patients' perceptions of symptom intensity and incapacitation within racial/ethnic groups related to socioeconomic status, as well as in specific behavior and motivation in seeking care. The study concluded that socioeconomic status as determined by hospital site exerted a stronger influence on patients' care-seeking behavior for acute chest pain than racial/ethnic status. Specific care-seeking behaviors of minority and lower-socioeconomic-status patients in the use of medications and paramedics in the face of acute symptoms should be targeted in future educational programs.

Acute chest pain in African Americans: factors in the delay in seeking emergency care.

OBJECTIVES: African Americans have been shown to have longer delay times than the majority population in seeking care for acute cardiac problems. The purpose of this study was to determine whether socioeconomic factors affect delay times. METHODS: Structured interviews were administered to 254 African Americans admitted to a public hospital and 194 African Americans admitted to a private hospital for suspected acute myocardial infarction. RESULTS: Patient characteristics found by multiple regression analysis to affect decision-making and travel time for care-seeking were structural access to care, persistence of symptoms, degree of incapacitation, consultation with a layperson, consultation with medical professionals, and mode of transportation. CONCLUSIONS: Within-group differences were found to be related to socioeconomic status. Strategies to increase knowledge about heart attack symptoms, improve access to care, and improve the socioeconomic status of at-risk African Americans are indicated.

Risk factors and mortality among black, Caucasian, and Latina women with acute myocardial infarction.

The purpose of this study was to examine the clinical outcome of acute myocardial infarction among women of three ethnic/racial groups and to determine whether observed differences in outcome are explained by differences in associated risk factors. Nine hundred seventeen (917) consecutive admissions occurred among 810 women, of whom 347 (42.8%) were Caucasian, 258 (31.9%) were black, and 205 (25.3%) were Latina. The overall mortality rate was 13%; the Caucasian rate was significantly higher than the Latina rate (16.9% vs 7%, p < 0.01), as was the black rate (13.8% vs 7%, p < 0.05). Comparing survivors with nonsurvivors among the three groups, hypertension was more common for survivors among blacks, as was a history of angina; in-hospital congestive failure was associated with a higher mortality for blacks and Caucasians, as was in-hospital angina for Caucasians. Univariate and multivariate logistic regression for the outcome variables of congestive failure, in-hospital angina, and mortality, showed race to be a significant factor in the lower mortality rate for Latinas in the univariate analysis. In the multivariate analysis, only in-hospital angina and congestive failure significantly influenced mortality. In this study of myocardial infarction among women of lower socioeconomic status, factors other than race were the primary influences on outcome.

Rose Questionnaire responses among black, Latino, and white subjects in two socioeconomic strata.

We administered the Rose Questionnaire to 1442 black, white, and Latino patients (approximately equal numbers) who sought care for acute chest pain at two medical centers. Of these, 718 subjects were enrolled at a large public hospital serving a low-socioeconomic status population and 724 at a large health maintenance organization hospital serving a middle-class clientele. Using the standard definition of Rose angina, multivariate logistic regression analysis identified five factors that contributed to the relative risk of a positive response: family history of myocardial infarction (2.48), history of peripheral vascular disease (1.41), history of high blood pressure (1.29), history of high cholesterol (1.26), and low-socioeconomic status hospital (0.78). Inquiring about shortness of breath as a substitute for chest pain or an alternative complaint in set one of the Rose Questionnaire did not increase the number of positive responses or differentiate between the socioeconomic groups or race-ethnic subgroups. Having a prior history of self-reported risk factors clearly defined a group with greater likelihood of a positive response to the Rose Questionnaire. Receiving care at a large public hospital (ie, being in a low-socioeconomic status group) was associated with reduced likelihood of having "typical" angina in comparison to receiving care at a health maintenance organization (middle socioeconomic status) for white subjects but not for Latinos and blacks.