Prevention of sexually transmitted human immunodeficiency virus (HIV) infection in adolescents

Sexual behavior can threaten the physical and social well-being of young people in the United States in a variety of ways, as it can put them at risk for infection with the human immunodeficiency virus (HIV), other sexually-transmitted diseases (STDs) and unintended pregnancy. This review describes the current extent of HIV infection in American adolescents, identifies and characterizes particular high-risk groups and risk-bearing and protective behaviors, and identifies barriers to adopting preventive behaviors and using health care services. Our main focus is to present findings from intervention research; we summarize the effects of strategies that operate at the individual level (i.e. biomedical or behavioral, in and outside of the clinic) and environmental level (i.e. family, school and community behavioral) to influence behavioral change and the prevention of HIV infection. Overall, even though abstinence eliminates the risk altogether and the use of condoms can effectively reduce the risk of sexual transmission of HIV, adolescents do not optimally employ these practices. Various approaches to counseling by providers and other behavioral interventions aimed at reducing high-risk sexual behavior have been effective, but have met with limited and short-lived success. Among the areas receiving inadequate attention to date have been the link between biomedical and community-based behavior change interventions and the correspondence of biologic and behavioral outcomes. These areas are explored and directions for future research are suggested.     

Verbal Working Memory and Atherosclerosis in Patients with Cardiovascular Disease: An fMRI study

BACKGROUND AND PURPOSE: Intimal-medial thickening (IMT) of the carotid wall is an accepted peripheral marker of atherosclerosis. It is associated with increased risk for myocardial infarction and stroke, and lower attention-executive-psychomotor functioning. The purpose of this study was to examine the relationship between IMT and brain activity during a verbal working memory (VWM) task in patients with cardiovascular disease (CVD). METHODS: Thirteen CVD patients underwent functional magnetic resonance imaging (fMRI) during a 2-Back VWM task, and B-mode ultrasound of the carotid arteries. IMT was calculated using an automated algorithm based on a validated edge-detection technique. The relationship between IMT and 2-Back-related brain activity was modeled using partial correlations controlling for age and small vessel disease as measured by white matter signal hyperintensities on MRI (WMH). RESULTS: Higher IMT was associated with lower 2-Back-related signal intensity and in the right middle frontal gyrus, independent of age and WMH. CONCLUSIONS: IMT may be one mechanism contributing to brain dysfunction in CVD. The blood oxygenation level-dependent (BOLD) contrast appears to be highly sensitive to peripheral vascular health as measured by IMT. Future studies should examine the sensitivity and specificity of the BOLD response for predicting cognitive decline in CVD.     

Sympathetic tone restrains arterial distensibility of healthy and atherosclerotic subjects.

BACKGROUND: Sympathetic activation induced by cold pressor test or cigarette smoking is accompanied by a marked reduction of radial artery distensibility. It is not known, however, whether arterial distensibility is under tonic sympathetic restraint, or whether this restraint involves arteries greater than the radial one in both normal and pathological conditions. METHODS: We studied the distensibility of radial artery by continuous ultrasonographic assessment of the changes in arterial diameter over the diasto-systolic pressure range (finger pressure measurement) in eight patients with a Dupuytren disease before and 20 min after ipsilateral brachial plexus anaesthesia. We also studied ultrasonographic distensibility of femoral artery in seven subjects before and 20 min after ipsilateral subarachnoid anaesthesia, performed before arthroscopic surgery, and in five patients with claudicatio intermittens before and 1 month after ipsilateral removal of the lumbar sympathectomy chain. In all three conditions, the contralateral artery served as control. RESULTS: The three interventions did not cause any significant alteration in blood pressure and heart rate. Radial artery distensibility was markedly increased by ipsilateral anaesthesia of the brachial plexus (+36%, P<0.01). This was the case also for femoral artery distensibility both following ipsilateral subarachnoid anaesthesia in healthy subjects (+47%, P<0.05) or ipsilateral sympathetic gangliectomy in patients with peripheral artery disease (+26%, P<0.05). In all three instances, the distensibility of the contralateral artery remained unaffected. CONCLUSIONS: These data indicate that the sympathetic nervous system exerts a marked tonic restraint of arterial distensibility. This restraint involves medium-size and large muscular arteries and can also be seen in subjects with peripheral artery disease. This stiffening influence may increase the traumatic effect of intravascular pressure on the vessel wall and favour atherosclerosis.     

Depiction of pain in the self-drawings of children with sickle cell disease

In an attempt to explore the perception of pain in children, 30 children with sickle cell disease were asked to make two drawings; one of themselves and one of themselves in pain. It was hypothesized that the cognitive ability and the emotional state of the child would be affected by the pain experience. Children and their parents were interviewed on the incidence of pain and on the child's control over it. The cognitive ability of the child was related to the kind of control he/she exercised over the pain. An analysis of the drawings concerning their thematic representations, colour and size is also presented. The mental age of the child dropped in the drawing of pain as compared to the non-pain drawing but it was found to be irrelevant to the kind of control the child exercised on the pain.     

Novel Approach to Inpatient Glucometric Monitoring and Variability in a Community Hospital Setting

Background:

Hyperglycemia and glucose variability in the hospital environment are associated with higher rates of complications, longer lengths of stay, and mortality. Standardized metrics are needed to assess the efficacy and safety of glucose management interventions.

Methods:

Glucometric data were collected from 2024 inpatients in a San Diego hospital between 2009 and 2011. As a complementary measure of glucose control, individual patient excursion rates were calculated using counts of distinct excursions from normal to critical glucose ranges >180 or <70 mg/dL. Prediction models for excursion rates were devised, based on patient demographic and clinical characteristics.

Results:

Patients were predominantly male (51.2%), Caucasian (86.0%), and elderly (median age 72 years). Obesity was prevalent: 32% were overweight and 33% were obese. Median length of hospitalization was 5.0 days (range, 0.8-139.4 days). Unadjusted rate of excursions >180 mg/dL was 0.456 per 24 hours. The proportion of zero excursions decreased as severity of illness decreased, but was unrelated to age. Excursion rates were slightly smaller for major and extreme severity of illness compared to mild or moderate illness severity. Excursion rates did not vary in a monotone fashion with age, although the general pattern reflected a reduction in excursion rates from the first age quartile (19 to 59) through the last age quartile (83 to 100). Using the Akaike information criterion, zero-inflated negative binomial models were identified as appropriate for analyzing glucose excursion rates.

Conclusions:

Systematic approaches to glucose reporting and management in the hospital environment offer “windows of opportunity” to improve diabetes care.     

Primary unilateral tuberculous inguinal lymphadenitis

We report the case of a young Greek woman who presented with erythema nodosum and isolated unilateral inguinal lymphadenopathy. Excision and biopsy of the lymph node showed infection due to M. tuberculosis. An extensive workup did not reveal any other foci of tuberculosis. Isolated tuberculous inguinal lymphadenitis is a rare entity in developed countries and is almost always bilateral. Our case is unique because the disease was unilateral and affected an otherwise healthy woman who had never traveled in endemic areas.     

Lyso-lecithin fragility in blackwater fever and haemolytic jaundice

Red cells transfused into a case of haemolysing blackwater fever are destroyed just as readily as the patient's own cells, making it appear that it is not the red cells that are at fault in this condition, but that there is some circulating haemolysin.By an improved spectrophotometric technique it has now been shown that, like those of haemolytic jaundice, the red cells from blackwater fever have an increased fragility to lyso-lecithin, although their fragility to saline is normal, unlike that of the cells of haemolytic jaundice.These two facts taken together make it seem that in blackwater fever the cells may possess some abnormal feature, but that this is probably secondary to more fundamental changes that take place in the cells' environment. By using van Boros' formula it is possible to demonstrate that spherocytosis occurs in blackwater fever and is accompanied by decreases in diameter-thickness ratio, volumes and areas; that these changes in blackwater fever are intermediate between those taking place in haemolytic jaundice and normal controls, and are not related in blackwater fever to changes in hypotonic saline fragility. It is probable that the initial stage in the destruction of the cells is a change in the permeability of the cell membrane, which allows haemoglobin to escape. The cells have later been seen to swell, become “transparent,” and then to disappear. That they have not been broken up can be shown by resuspending them in saline when the “ghosts” reappear. This phenomenon takes place in both lyso-lecithin and snake venom haemolysis. If the process is allowed to continue the cells are finally disrupted, and will not reappear on saline resuspension.In haemolytic jaundice it seems that there may be some defect in the red cell as well as some “splenic factor,” shown by the fact that splenectomy fails to alter the abnormal fragility of the cells to saline, but does stop the periodic haemolysis. A combination of both abnormal cells and splenic factors would seem to be necessary for the destruction of the red cells in this condition. The same cannot be determined for blackwater fever.The enlargement of the spleen in so many of these haemolytic conditions is regarded by many as of considerable significance. The production of lyso-lecithin as a result of the separation of the cells and plasma in this organ has led to the suggestion that this powerfully haemolytic substance may play a part in the haemolyses of certain of these conditions.It is possible that lyso-lecithin fragility is in some way related to the action of this substance on the lipoids or lipo-protein complex in the red cell membrane. It has been shown that the amount of lipoid present in the cell envelope is closely related to the dimensions of the cell, and that the ability of the cell to increase its volume without being disrupted is related to the lipo-protein ratio in its membrane.The kinetics of lyso-lecithin haemolysis have not been worked out, but there is some ground for regarding the process as one of enzyme action where the enzyme lecithinase acting on a substrate of red cells or plasma lecithin results in the production of lyso-lecithin or some allied phosphatide. Lecithinase has been shown to be present in many conditions where haemolytic reactions take place, such as in favism, snake poisoning, Cl. welchii filtrates as well as in the spleen and peripheral blood. The degradation products of the action of lecithinase on lecithin are not always the same, nor are the various lecithinases alike.Although the end product of the action of snake venom lecithinase on lecithin is lyso-lecithin, yet this substance when injected into baboons in relatively huge amounts produces no haemolysis, and only a slight shift of the Price-Jones curve to the right. This is in sharp contrast to the haemolysis that follows the injection of snake venom freed of its neurotoxic factor. It is suggested that this difference may be due to the fact that in the former case the lecithin in the cells and/or plasma is not disturbed, whilst in the case of snake venom injection of the lecithinase present in the venom will split the lecithin of the cells and/or plasma and so disturb the intracellular lipo-protein complex.The part played by the reticulo-endothelial system in the haemolytic process is briefly discussed—the resulting decision being that no precise data are available to enable any conclusions to be reached either upon the part that this system plays in actually destroying red cells, or elaborating haemolysins that later lyse the cells.Proteolytic enzymes may be produced in the macrophages of the reticulo-endothelial system and these have been shown to be capable of destroying red and white cells.