The relationship between anxiety disorders and alcohol use disorders: a review of major perspectives and findings

It is generally agreed that problems related to alcohol use and anxiety tend to occur within the same individual ("comorbidity"); however, the cause of this association remains controversial. Three prominent perspectives are that anxiety disorder promotes pathological alcohol use, that pathological alcohol use promotes anxiety disorder and that a third factor promotes both conditions. We review laboratory, clinical, family, and prospective studies bearing on the validity of these explanatory models. Findings converge on the conclusion that anxiety disorder and alcohol disorder can both serve to initiate the other, especially in cases of alcohol dependence versus alcohol abuse alone. Further, evidence from clinical studies suggests that anxiety disorder can contribute to the maintenance of and relapse to pathological alcohol use. Relying heavily on pharmacological and behavioral laboratory findings, we tentatively propose that short-term anxiety reduction from alcohol use, in concert with longer-term anxiety induction from chronic drinking and withdrawal, can initiate a vicious feed-forward cycle of increasing anxiety symptoms and alcohol use that results in comorbidity.     

The effect of increased sodium in the drinking water on right ventricular hypertrophy, right ventricular failure and ascites in broiler chickens

One hundred commercial male broiler chickens were grown to 27 days in four floor pens on a commercial diet containing 0.14% sodium (Na+). From day 6 each pen received different levels of sodium chloride (NaCl) in the drinking water; 0.0%, 0.15% (0.06% Na+), 0.3% (0.12% Na+) and 0.6% (0.24% Na+). Eight chicks from each group were killed at 13, 20 and 27 days and examined for right ventricular hypertrophy (RVH) and right ventricular failure (RVF). By day 27 as little as 0.06% added Na+ caused two cases of RVH and one case of RVF with ascites, typical of the ascites caused by RVF in commercial broilers. RVH, RVF and ascites developed earlier in broilers on higher levels of Na+.     

The variation in isometric tension with sarcomere length in vertebrate muscle fibres

1. The variation of isometric tetanus tension with sarcomere length in single fibres from frog striated muscle has been re-investigated with special precautions to ensure uniformity of sarcomere length within the part of the fibre being studied.2. In most respects the results of Ramsey & Street (1940) were confirmed, but (a) the peak of the curve was found to consist of a plateau between sarcomere lengths of 2.05 and 2.2 mu, (b) the decline of tension above this plateau is steeper than found by Ramsey & Street, and (c) the decline of tension below the plateau becomes suddenly steeper at a sarcomere length of about 1.67 mu.3. Many features of this length-tension relation are simply explained on the sliding-filament theory.4. It is concluded that, in the plateau and at greater lengths, the tension on each thin filament is made up of equal contributions from each bridge which it overlaps on adjacent thick filaments.5. Internal resistance to shortening is negligible in this range but becomes progressively more important with shortening below the plateau.     

Prevention of mother-to-child transmission of HIV--successes, controversies and critical questions

In a relatively short period of time enormous strides have been made in the field of mother-to-child transmission (MTCT) of HIV. Timing, mechanisms and risk factors for transmission have been elucidated and a large number of drug regimens have been shown to effectively reduce the risk of HIV infection in the child. A number of observations can be gleaned from the work that has been done to design and implement HIV perinatal prevention programs. First, pregnancy is a critical time to identify women with HIV infection and to link them and their families to ongoing HIV care and treatment In addition to providing perinatal prevention intervention, pregnancy serves as an entry point into the health-care system. There is a unique opportunity to link prevention and treatment efforts, two programmatic areas often viewed as conflicting and competing. Second, the evolution of perinatal prevention in high-resource settings and, to an increasing extent, more resource-constrained areas, reflects the interplay of science and public-health policy. Results of clinical trials and epidemiologic studies have progressively provided recommendations and guidelines for HIV counseling, testing and treatment for perinatal prevention. In many ways, the successes of perinatal prevention in the USA attest to the success of the dynamic interaction between health, science, and public policy. There is great hope and expectation that the next decade will be equally successful as care and treatment becomes increasingly available in resource-constrained settings. Third, a key element of perinatal prevention is the provision of safe and effective family planning to women of childbearing years. Many women, particularly in low-resource settings, have multiple pregnancies, influenced by cultural imperatives and limited access to safe, affordable contraception. Enhancing these services will enable women to make informed decisions about their health, their families, and their futures. Finally, it is critical to remember that primary prevention of HIV infection in women holds the true key to perinatal prevention. While work must continue to identify more efficacious and safe regimens to prevent MTCT, preventing women from becoming HIV-infected should remain the true measure of success.     

Quantitative measurement of IgE antibodies to purified allergens using streptavidin linked to a high-capacity solid phase

BACKGROUND: Commercially available assays for IgE antibody provide results in international units per milliliter for many allergen extracts, but this is not easily achieved with purified or novel allergens. OBJECTIVE: To develop assays for IgE antibody suitable for purified or novel allergens by using a commercially available immunosorbent. METHODS: Streptavidin coupled to a high-capacity immunosorbent (CAP) was used to bind biotinylated purified allergens from mite (Der p 1 and Der p 2), cat (Fel d 1), and dog (Can f 1). Assays for IgE antibody to these allergens were performed on sera from children (asthma and control) as well as adults with atopic dermatitis. RESULTS: The results were validated by serial dilution of sera with high and low levels of IgE antibody and were quantitated in international units per milliliter by using a standard curve. Values for IgE antibody to Der p 1, Der p 2, and Fel d 1 correlated with values obtained with the allergen extracts (r2 = 0.80, 0.84, and 0.95, respectively; P < .001 in each case). Furthermore, the values for IgE antibody in sera from children with high exposure to mite and cat allergens demonstrated 10-fold higher levels of IgE antibody to Der p 1 and Der p 2 than to Fel d 1 (P < .001). CONCLUSION: The streptavidin immunosorbent technique provides a new method for quantifying IgE antibody to purified proteins. The results provide evidence about the high quantities of IgE antibody to purified inhalant allergens in patients with atopic dermatitis. In addition, the results demonstrate major differences in IgE antibodies specific for mite and cat allergens among children with high exposure to both allergens.     

The impact of testing accommodations on MCAT scores: descriptive results.

PURPOSE: Medical College Admission Test (MCAT) examinees with disabilities who receive accommodations receive flagged scores indicating nonstandard administration. This report compares MCAT examinees who received accommodations and their performances with standard examinees. METHOD: Aggregate history records of all 1994-2000 MCAT examinees were identified as flagged (2,401) or standard (297,880), then further sorted by race/ethnicity (broadly identified as underrepresented minority and non-URM, at the time of testing) and gender. Those with flagged scores were also classified by disability (LD = learning disability, ADHD = attention deficit hyperactivity disorder, LD/ADHD = learning disability and attention deficit hyperactivity disorder, and Other = other disability) and type of accommodation. Mean MCAT scores were calculated for all groups. A group of 866 examinees took the MCAT first as a standard administration and subsequently with accommodations. In a separate analysis, their two sets of scores were compared. RESULTS: Less than 1% of examinees (2,401) had accommodations; of these, 55% were LD, 17% ADHD, 5% LD/ADHD, and 23% Other. Extended time was the most frequently provided accommodation. Mean flagged scores slightly exceeded mean standard scores on all MCAT sections. Examinees who retook the MCAT with accommodations after a standard administration increased their scores by six points, quadrupling the average gain Standard-Standard retest cohort from another study. CONCLUSION: The small but statistically significant different higher flagged scores may reflect either appropriate compensation or overly generous accommodations. Extended time had a positive impact on the scores of those who retested with this accommodation. The validity the flagged MCAT in predicting success in medical school is not known, and further investigation is underway.     

The rhythm of the heart in the blink of an eye: emotion-modulated startle magnitude covaries with heart rate variability

Emotion-modulated startle is a robust phenomenon that has been demonstrated in a wide range of experimental situations. Similarly, heart rate variability (HRV) has been associated with a diverse range of processes including affective and attentional regulation. The present study sought to examine the relationship between these two important measures of affective behavior. Ninety female participants viewed pleasant, neutral, and unpleasant pictures while exposed to acoustic startle stimuli. The eyeblink startle was recorded both during the affective foregrounds and during intertrial intervals. HRV was assessed during a resting baseline and relationships between HRV and startle magnitudes examined. Results indicated that resting HRV was inversely related to startle magnitude during both intertrial intervals and affective foregrounds. In addition, the participants with the highest HRV showed the most differentiated emotion-modulated startle effects, whereas those with the lowest HRV, compared to those with the highest HRV, showed significantly potentiated startle to neutral foregrounds and marginally potentiated startle to pleasant foregrounds. The findings are consistent with models that posit that prefrontal cortical activity modulates subcortical motivation circuits. These results have important implications for the use of startle probe methodology and for HRV in the study of emotional regulation and dysregulation.