Whole-genome analyses resolve early branches in the tree of life of modern birds

To better determine the history of modern birds, we performed a genome-scale phylogenetic analysis of 48 species representing all orders of Neoaves using phylogenomic methods created to handle genome-scale data. We recovered a highly resolved tree that confirms previously controversial sister or close relationships. We identified the first divergence in Neoaves, two groups we named Passerea and Columbea, representing independent lineages of diverse and convergently evolved land and water bird species. Among Passerea, we infer the common ancestor of core landbirds to have been an apex predator and confirm independent gains of vocal learning. Among Columbea, we identify pigeons and flamingoes as belonging to sister clades. Even with whole genomes, some of the earliest branches in Neoaves proved challenging to resolve, which was best explained by massive protein-coding sequence convergence and high levels of incomplete lineage sorting that occurred during a rapid radiation after the Cretaceous-Paleogene mass extinction event about 66 million years ago.

Missense mutations in the rod domain of the lamin A/C gene as causes of dilated cardiomyopathy and conduction-system disease

BACKGROUND

Inherited mutations cause approximately 35 percent of cases of dilated cardiomyopathy; however, few genes associated with this disease have been identified. Previously, we located a gene defect that was responsible for autosomal dominant dilated cardiomyopathy and conduction-system disease on chromosome 1p1-q21, where nuclear-envelope proteins lamin A and lamin C are encoded by the LMNA (lamin A/C) gene. Mutations in the head or tail domain of this gene cause Emery-Dreifuss muscular dystrophy, a childhood-onset disease characterized by joint contractures and in some cases by abnormalities of cardiac conduction during adulthood.

METHODS

We evaluated 11 families with autosomal dominant dilated cardiomyopathy and conduction-system disease. Sequences of the lamin A/C exons were determined in probands from each family, and variants were confirmed by restriction-enzyme digestion. The genotypes of the family members were ascertained.

RESULTS

Five novel missense mutations were identified: four in the alpha-helical-rod domain of the lamin A/C gene, and one in the lamin C tail domain. Each mutation caused heritable, progressive conduction-system disease (sinus bradycardia, atrioventricular conduction block, or atrial arrhythmias) and dilated cardiomyopathy. Heart failure and sudden death occurred frequently within these families. No family members with mutations had either joint contractures or skeletal myopathy. Serum creatine kinase levels were normal in family members with mutations of the lamin rod but mildly elevated in some family members with a defect in the tail domain of lamin C.

CONCLUSIONS

Genetic defects in distinct domains of the nuclear-envelope proteins lamin A and lamin C selectively cause dilated cardiomyopathy with conduction-system disease or autosomal dominant Emery-Dreifuss muscular dystrophy. Missense mutations in the rod domain of the lamin A/C gene provide a genetic cause for dilated cardiomyopathy and indicate that this intermediate filament protein has an important role in cardiac conduction and contractility.

Chemoprevention of gastric dysplasia: randomized trial of antioxidant supplements and anti-helicobacter pylori therapy

BACKGROUND

Previous research has identified a high risk of gastric carcinoma as well as a high prevalence of cancer precursor lesions in rural populations living in the province of Nariño, Colombia, in the Andes Mountains.

METHODS

A randomized, controlled chemoprevention trial was conducted in subjects with confirmed histologic diagnoses of multifocal nonmetaplastic atrophy and/or intestinal metaplasia, two precancerous lesions. Individuals were assigned to receive anti-Helicobacter pylori triple therapy and/or dietary supplementation with ascorbic acid, beta-carotene, or their corresponding placebos. Gastric biopsy specimens taken at baseline were compared with those taken at 72 months. Relative risks of progression, no change, and regression from multifocal nonmetaplastic atrophy and intestinal metaplasia were analyzed with multivariate polytomous logistic regression models to estimate treatment effects. All statistical tests were two-sided.

RESULTS

All three basic interventions resulted in statistically significant increases in the rates of regression: Relative risks were 4.8 (95% confidence interval [CI] = 1.6-14.2) for anti-H. pylori treatment, 5. 1 (95% CI = 1.7-15.0) for beta-carotene treatment, and 5.0 (95% CI = 1.7-14.4) for ascorbic acid treatment in subjects with atrophy. Corresponding relative risks of regression in subjects with intestinal metaplasia were 3.1 (95% CI = 1.0-9.3), 3.4 (95% CI = 1.1-9.8), and 3.3 (95% CI = 1.1-9.5). Combinations of treatments did not statistically significantly increase the regression rates. Curing the H. pylori infection (which occurred in 74% of the treated subjects) produced a marked and statistically significant increase in the rate of regression of the precursor lesions (relative risks = 8.7 [95% CI = 2.7-28.2] for subjects with atrophy and 5.4 [95% CI = 1.7-17.6] for subjects with intestinal metaplasia).

CONCLUSIONS

In the very high-risk population studied, effective anti-H. pylori treatment and dietary supplementation with antioxidant micronutrients may interfere with the precancerous process, mostly by increasing the rate of regression of cancer precursor lesions, and may be an effective strategy to prevent gastric carcinoma.

Urban epidemic of severe leptospirosis in Brazil. Salvador Leptospirosis Study Group

BACKGROUND

Leptospirosis has, traditionally, been considered a sporadic rural disease. We describe a large urban outbreak of leptospirosis.

METHODS

Active surveillance for leptospirosis was established in an infectious-disease referral hospital in Salvador, Brazil, between March 10 and Nov 2, 1996. Patients meeting case criteria for severe manifestations of leptospirosis were recruited into the study. The diagnosis was confirmed in the laboratory with the microagglutination test and identification of leptospires in blood or urine. Risk factors for death were examined by multivariate analyses.

FINDINGS

Surveillance identified 326 cases of which 193 (59%) were laboratory-confirmed (133) or probable (60) cases. Leptospira interrogans serovar copenhageni was isolated from 87% of the cases with positive blood cultures. Most of the cases were adult (mean age 35.9 years [SD 15.9]), and 80% were male. Complications included jaundice (91%), oliguria (35%), and severe anaemia (26%). 50 cases died (case-fatality rate 15%) despite aggressive supportive care including dialysis (in 23%). Altered mental status was the strongest independent predictor of death (odds ratio 9.12 [95% CI 4.28-20.3]), age over 37 years, renal insufficiency, and respiratory insufficiency were also significant predictors of death. Before admission to hospital, 42% were misdiagnosed as having dengue fever in the outpatient clinic; an outbreak of dengue fever was taking place concurrently.

INTERPRETATION

An epidemic of leptospirosis has become a major urban health problem, associated with high mortality. Diagnostic confusion with dengue fever, another emerging infectious disease with a similar geographic distribution, prevents timely intervention that could minimise mortality.

A venue-based method for sampling hard-to-reach populations

Constructing scientifically sound samples of hard-to-reach populations, also known as hidden populations, is a challenge for many research projects. Traditional sample survey methods, such as random sampling from telephone or mailing lists, can yield low numbers of eligible respondents while non-probability sampling introduces unknown biases. The authors describe a venue-based application of time-space sampling (TSS) that addresses the challenges of accessing hard-to-reach populations. The method entails identifying days and times when the target population gathers at specific venues, constructing a sampling frame of venue, day-time units (VDTs), randomly selecting and visiting VDTs (the primary sampling units), and systematically intercepting and collecting information from consenting members of the target population. This allows researchers to construct a sample with known properties, make statistical inference to the larger population of venue visitors, and theorize about the introduction of biases that may limit generalization of results to the target population. The authors describe their use of TSS in the ongoing Community Intervention Trial for Youth (CITY) project to generate a systematic sample of young men who have sex with men. The project is an ongoing community level HIV prevention intervention trial funded by the Centers for Disease Control and Prevention. The TSS method is reproducible and can be adapted to hard-to-reach populations in other situations, environments, and cultures.

Preferences for quality of life or survival expressed by patients with heart failure

BACKGROUND

As many patients with heart failure develop symptoms limiting daily life, newer therapies may be found to improve functional status without concomitant survival benefit. As some of these therapies may actually increase mortality, it is increasingly relevant to assess patients' preferences for survival vs improvement in symptoms.

METHODS

We enrolled 99 patients with advanced heart failure (ejection fraction 24 +/- 10, duration 6 +/- 5 years). Each patient completed time trade-off and standard gamble instruments, Minnesota Living with Heart Failure questionnaires and visual analog scales for dyspnea and overall health. Jugular venous pressure was assessed in all patients and peak oxygen consumption was measured during bicycle exercise in 60 patients.

RESULTS

Strong polarity of preference toward either survival or quality of life was expressed by 60% of patients. There was good correlation between time trade-off and standard gamble utility scores (r = 0.64), and between preference and functional class (r = 0.60). Higher jugular venous pressure and lower peak oxygen consumption were associated with poorer utility scores (p <.05). Higher dyspnea scores and worse Living with Heart Failure scores were also associated with preference to trade time or take risks for better health.

CONCLUSIONS

These findings suggest that heart failure patients express meaningful preferences about quality vs length of life. High jugular venous pressure, low peak oxygen consumption and poor Living with Heart Failure scores were related to low utility scores. These cannot be assumed, however, to predict the intensity of individual preference to trade nothing or virtually everything for better health.

New perspectives on a subclinical form of visceral leishmaniasis

During an epidemiological study of visceral leishmaniasis in an endemic region of Brazil, new perspectives emerged on a subclinical form of the disease. A group of 86 children with antibody to Leishmania were identified. None of these children had a history of leishmaniasis. The children were segregated into four groups: One group remained asymptomatic (n = 20), whereas another developed classic kala-azar within weeks of the index serology (n = 15). The remaining 51 patients initially had subclinical disease; 13 (25%) of these patients progressed to classic kala-azar (mean, five months). The others (75%) resolved their illness after a prolonged period (mean, 35 months). The initial illness in the subclinical group was characterized by hepatomegaly, frequent splenomegaly, intermittent cough, diarrhea, and low-grade fever. Malaise and poor weight gain were common. Giemsa-stained smears and cultures of bone marrow aspirates were usually negative for Leishmania in the absence of symptoms of classic kala-azar.

Early versus standard antiretroviral therapy for HIV-infected adults in Haiti

BACKGROUND

For adults with human immunodeficiency virus (HIV) infection who have CD4+ T-cell counts that are greater than 200 and less than 350 per cubic millimeter and who live in areas with limited resources, the optimal time to initiate antiretroviral therapy remains uncertain.

METHODS

We conducted a randomized, open-label trial of early initiation of antiretroviral therapy, as compared with the standard timing for initiation of therapy, among HIV-infected adults in Haiti who had a confirmed CD4+ T-cell count that was greater than 200 and less than 350 per cubic millimeter at baseline and no history of an acquired immunodeficiency syndrome (AIDS) illness. The primary study end point was survival. The early-treatment group began taking zidovudine, lamivudine, and efavirenz therapy within 2 weeks after enrollment. The standard-treatment group started the same regimen of antiretroviral therapy when their CD4+ T-cell count fell to 200 per cubic millimeter or less or when clinical AIDS developed. Participants in both groups underwent monthly follow-up assessments and received isoniazid and trimethoprim-sulfamethoxazole prophylaxis with nutritional support.

RESULTS

Between 2005 and 2008, a total of 816 participants--408 per group--were enrolled and were followed for a median of 21 months. The CD4+ T-cell count at enrollment was approximately 280 per cubic millimeter in both groups. There were 23 deaths in the standard-treatment group, as compared with 6 in the early-treatment group (hazard ratio with standard treatment, 4.0; 95% confidence interval [CI], 1.6 to 9.8; P=0.001). There were 36 incident cases of tuberculosis in the standard-treatment group, as compared with 18 in the early-treatment group (hazard ratio, 2.0; 95% CI, 1.2 to 3.6; P=0.01).

CONCLUSIONS

Early initiation of antiretroviral therapy decreased the rates of death and incident tuberculosis. Access to antiretroviral therapy should be expanded to include all HIV-infected adults who have CD4+ T-cell counts of less than 350 per cubic millimeter, including those who live in areas with limited resources. (ClinicalTrials.gov number, NCT00120510.)

Effect of isoniazid prophylaxis on incidence of active tuberculosis and progression of HIV infection

Tuberculosis occurring with human immunodeficiency virus (HIV) infection is a serious and growing public health problem. We have carried out a randomised clinical trial of a 12-month course of isoniazid plus vitamin B6 versus vitamin B6 alone in Port-au-Prince, Haiti, to assess the efficacy of isoniazid in preventing active tuberculosis in symptom-free HIV-infected individuals. The effect of prophylaxis on the development of HIV disease, AIDS, and death was also investigated. 118 subjects were assigned treatment with isoniazid plus B6 (n = 58) or B6 alone (n = 60) between 1986 and 1989. The treatment groups were similar at study entry in demographic, clinical, and immunological characteristics. Interim analysis in 1990 revealed no significant difference in tuberculosis outcome measures. Follow-up was continued until 1992, at which time significant protection by isoniazid against the development of tuberculosis was apparent, both for the whole study population and for subjects positive for purified protein derivative of tuberculin (PPD). The incidence of tuberculosis was lower in isoniazid recipients than in patients who received B6 alone (2.2 vs 7.5 per 100 person-years). The relative risk of tuberculosis was 3.4 (95% CI 1.1-10.6) for B6 alone versus isoniazid plus B6 (p < 0.05). Isoniazid also delayed progression to HIV disease and AIDS and death. Thus isoniazid effectively decreases the incidence of tuberculosis and delays the onset of HIV-related disease in symptom-free HIV-seropositive individuals. Isoniazid prophylaxis should be considered for HIV-seropositive, PPD-positive subjects, and may also be appropriate for PPD-negative patients in areas where tuberculosis is highly endemic.

Freedom from congestion predicts good survival despite previous class IV symptoms of heart failure

BACKGROUND

This study determined whether evidence of congestion after 4 to 6 weeks of heart failure management predicted outcome for patients hospitalized with chronic New York Heart Association class IV symptoms. Class IV symptoms predict high mortality rates, but outcome is not known for patients who improve to establish freedom from congestion. Revised estimates at 1 month could facilitate decisions regarding transplantation and other high-risk interventions.

METHODS

At 4 to 6 weeks after hospital discharge, 146 patients were evaluated for congestion by 5 criteria (orthopnea, jugular venous distention, edema, weight gain, and new increase in baseline diuretics). Heart failure management included inpatient therapy tailored to relieve congestion, followed by adjustments to maintain fluid balance during the next 4 weeks.

RESULTS

Freedom from congestion was demonstrated at 4 to 6 weeks in 80 (54%) patients, who had 87% subsequent 2-year survival compared with 67% in 40 patients with 1 or 2 criteria of congestion and 41% in 26 patients with 3 to 5 criteria. The Cox proportional hazards model identified left ventricular dimension, pulmonary wedge pressure on therapy, and freedom from congestion as independent predictors of survival. Persistence of orthopnea itself predicted 38% 2-year survival (without urgent transplantation) versus 77% in 113 without orthopnea. Serum sodium was lower and blood urea nitrogen and heart rate higher when orthopnea persisted.

CONCLUSIONS

The ability to maintain freedom from congestion identifies a population with good survival despite previous class IV symptoms. At 4 to 6 weeks, patients with persistent congestion may be considered for high-risk intervention.

Absence of gamma interferon and interleukin 2 production during active visceral leishmaniasis

The lymphocytes from eight patients with active visceral leishmaniasis (VL), a disease associated with marked immunologic dysfunction, were examined for ability to produce interleukin 2 (IL-2) and gamma interferon during in vitro cultivation. It was found that both IL-2 and gamma interferon production, in response to leishmania antigen, was absent during the active disease, but was restored after successful chemotherapy. Untreated VL patients produced IL-2 and gamma interferon when stimulated with phytohemagglutinin (PHA). Six patients with either active cutaneous or mucosal leishmaniasis, a disease not associated with immunosuppression, showed high levels of gamma interferon in response to leishmania antigen and PHA. Since IL-2 and gamma interferon have been shown to have important roles in the immune response and in the killing of leishmania, their absence may represent a key defect in the immune response in VL.

Two strategies to increase adherence to HIV antiretroviral medication: life-steps and medication monitoring

Advances in the medical treatment of HIV have made it clear that adherence to highly active antiretroviral treatment is a crucial feature for treatment success. The present paper had two goals: (1) to examine psychosocial predictors of adherence in persons receiving HIV antiretroviral therapy; (2) to compared two minimal-treatment interventions to increase HIV medication adherence in a subset of persons who self-reported less than perfect adherence. One of the interventions, Life-Steps, is a single-session intervention utilizing cognitive-behavioral, motivational interviewing, and problem-solving techniques. The other intervention, self-monitoring, utilizes a pill-diary and an adherence questionnaire alone. Significant correlates of adherence included depression, social support, adherence self-efficacy, and punishment beliefs about HIV. Depression was a significant unique predictor of adherence over and above the other variables. Both interventions yielded improvement in adherence from baseline, and the Life-Steps intervention showed faster improvements in adherence for persons with extant adherence problems.

A prospective study of visceral leishmaniasis in an endemic area of Brazil

The epidemiology, clinical patterns, and risk factors for visceral leishmaniasis were prospectively studied in an endemic area of Brazil. The prevalence of disease was 3.1% for children less than 15 years of age, and the annual incidence was 4.3 cases per 1,000 children. The number of children with disease fluctuated yearly and seasonally, and distribution of the disease varied within the endemic area. Risk factors included young age (median, three years) and malnutrition before the onset of disease. Intestinal parasitism, recent migration into the area, and house location within the area did not influence the progression of infection to disease. Serological testing indicated that 7.5% of children were infected with Leishmania each year and that the ratio of disease to infection was 1:18.5 for the whole area and 1:6.5 for the section with the highest prevalence of disease. Early diagnosis and therapy altered clinical patterns of the disease.

Genetic foundations of human intelligence

Individual differences in intelligence (cognitive abilities) are a prominent aspect of human psychology, and play a substantial role in influencing important life outcomes. Their phenotypic structure-as described by the science of psychometrics-is well understood and well replicated. Approximately half of the variance in a broad range of cognitive abilities is accounted by a general cognitive factor (g), small proportions of cognitive variance are caused by separable broad domains of mental function, and the substantial remainder is caused by variance that is unique to highly specific cognitive skills. The heritability of g is substantial. It increases from a low value in early childhood of about 30%, to well over 50% in adulthood, which continues into old age. Despite this, there is still almost no replicated evidence concerning the individual genes, which have variants that contribute to intelligence differences. Here, we describe the human intelligence phenotype, summarise the evidence for its heritability, provide an overview of and comment on molecular genetic studies, and comment on future progress in the field.

The left atrial appendage: our most lethal human attachment! Surgical implications

OBJECTIVES

To prevent death from atrial fibrillation, a cardiac disease which kills by producing emboli. Atrial fibrillation causes about 25% of strokes and increases stroke rate by five times. Over 90% of these embolic strokes are from clots originating in the left atrial appendage. This study addresses the surgical feasibility of removing the appendage to prevent future deaths in two subcategories of patients. (1) Prophylactic removal during open-heart surgery to study its safety. Theoretically, as these patients age and some develop atrial fibrillation, protection from embolic strokes would already be present. (2) Therapeutic removal in chronic atrial fibrillation patients by means of a thorascopic approach. Its technical feasibility is demonstrated. Its actual stroke prevention potential awaits large studies.

METHODS

Appendectomy has been evaluated three ways. (1) Experimentally, thorascopic appendage removal was performed on 20 goats with endoscopic approach. Late studies showed a cleanly healed atrial closure after stapling, and no puckering of tissue as seen with the purse-string approach. (2) Safety of human appendectomy was demonstrated in 437 patients (1995-1997). Routine appendectomy was performed during open-heart surgery. Forty-three appendages were stapled, 391 sutured off. (3) Thorascopic appendectomy in seven patients with chronic atrial fibrillation has been successfully accomplished as an isolated surgical procedure. Stapling or suture closure provides a much cleaner, non-puckered suture line than a purse string.

RESULTS

In prophylactic removal, no acute bleeding occurred. No late problems have been identified. Endoscopic removal of the appendage has been successful in seven atrial fibrillation patients.

CONCLUSIONS

The left atrial appendage is a lethal source of emboli in atrial fibrillation patients. As patients age and often develop atrial fibrillation, prophylactic appendage removal whenever the chest is open is suggested as a method to prevent future strokes. In chronic atrial fibrillation patients, appendectomy can be done with a mini-thorascopic approach. Further studies are planned to demonstrate the effectiveness of appendectomy in preventing strokes in the chronic fibrillating patients.

Cassini Radar Views the Surface of Titan

The Cassini Titan Radar Mapper imaged about 1% of Titan's surface at a resolution of approximately 0.5 kilometer, and larger areas of the globe in lower resolution modes. The images reveal a complex surface, with areas of low relief and a variety of geologic features suggestive of dome-like volcanic constructs, flows, and sinuous channels. The surface appears to be young, with few impact craters. Scattering and dielectric properties are consistent with porous ice or organics. Dark patches in the radar images show high brightness temperatures and high emissivity and are consistent with frozen hydrocarbons.

Antiretroviral therapy in a thousand patients with AIDS in Haiti

BACKGROUND

The one-year survival rate of adults and children with the acquired immunodeficiency syndrome (AIDS), without antiretroviral therapy, has been about 30 percent in Haiti. Antiretroviral therapy has recently become available in Haiti and in other developing countries. Data on the efficacy of antiretroviral therapy in developing countries are limited. High rates of coinfection with tropical diseases and tuberculosis, along with malnutrition and limited laboratory monitoring of therapy, may decrease the efficacy of antiretroviral therapy in these countries.

METHODS

We studied the efficacy of antiretroviral therapy in the first 1004 consecutive patients with AIDS and without previous antiretroviral therapy who were treated beginning in March 2003 in Port-au-Prince, Haiti.

RESULTS

During a 14-month period, three-drug antiretroviral therapy was initiated in 1004 patients, including 94 children under 13 years of age. At enrollment, the median CD4 T-cell count in adults and adolescents was 131 per cubic millimeter (interquartile range, 55 to 211 per cubic millimeter); in children, a median of 13 percent of T cells were CD4-positive (interquartile range, 8 to 20 percent). According to a Kaplan-Meier survival analysis, 87 percent of adults and adolescents and 98 percent of children were alive one year after beginning treatment. In a subgroup of 100 adult and adolescent patients who were followed for 48 to 56 weeks, 76 patients had fewer than 400 copies of human immunodeficiency virus RNA per milliliter. In adults and adolescents, the median increase in the CD4 T-cell count from baseline to 12 months was 163 per cubic millimeter (interquartile range, 77 to 251 per cubic millimeter). In children, the median percentage of CD4 T cells rose from 13 percent at baseline to 26 percent (interquartile range, 22 to 36 percent) at 12 months. Treatment-limiting toxic effects occurred in 102 of the 910 adults and adolescents (11 percent) and 5 of the 94 children (5 percent).

CONCLUSIONS

This report documents the feasibility of effective antiretroviral therapy in a large number of patients in an impoverished country. Overall, the outcomes are similar to those in the United States. These results provide evidence in support of international efforts to make antiretroviral therapy available to patients with AIDS in developing countries.

Cyclospora infection in adults infected with HIV. Clinical manifestations, treatment, and prophylaxis

OBJECTIVE

To determine the prevalence and clinical manifestations of Cyclospora in Haitians infected with human immunodeficiency virus (HIV) who have diarrhea and to evaluate therapy and prophylaxis.

DESIGN

Cohort study. From 1990 to 1993, stool samples were collected from adults seropositive for HIV who had had diarrhea for at least 3 weeks.

SETTING

A clinic in Haiti.

INTERVENTIONS

Stool samples were examined for enteric protozoa after acid-fast staining. Patients with Cyclospora infection were treated with trimethoprimsulfamethoxazole (160 mg and 800 mg, respectively) given orally four times a day for 10 days. After completion of therapy, patients were evaluated weekly and re-treated if clinical and parasitologic recurrences occurred, followed by trimethoprim-sulfamethoxazole prophylaxis three times a week.

RESULTS

804 of 2400 patients (33%) seropositive for HIV had a history of chronic or intermittent diarrhea; 502 of these 804 patients (62%) currently had diarrhea, and 450 patients each provided two stool specimens for examination. Enteric protozoa identified included Cryptosporidium (30%), Isospora belli (12%), Cyclospora species (11%), Giardia lamblia (3%), and Entamoeba histolytica (1%). Forty-three patients with diarrhea and Cyclospora infection were studied; their symptoms were indistinguishable from those seen in patients with isosporiasis or cryptosporidiosis. In all patients, diarrhea ceased and results from stool examinations were negative within 2.5 days after beginning oral trimethoprim-sulfamethoxazole therapy. Recurrent symptomatic cyclosporiasis developed in 12 of 28 patients (43%) followed for 1 month or more, but it also responded promptly to trimethoprim-sulfamethoxazole therapy. These 12 patients received trimethoprim-sulfamethoxazole three times a week as secondary prophylaxis, with only a single recurrence after 7 months.

CONCLUSION

Cyclospora infection is common in Haitian patients with HIV infection, responds to trimethoprim-sulfamethoxazole therapy, and has a high recurrence rate that can be largely prevented with long-term trimethoprim-sulfamethoxazole prophylaxis.

Role of sensory and cognitive information in the enhancement of certainty and liking for novel and familiar foods

Expected and actual liking for novel and familiar foods were examined under various conditions of sensory and verbal information with 121 subjects who differed in food neophobia. The possible mediating roles of uncertainty about product identity and resemblance to familiar foods were also investigated. Subjects were divided into three verbal information groups (no information; product name; ingredient and use information) balanced for neophobia, age and gender. All groups rated test samples under three sensory conditions: (1) appearance only, (2) appearance and smell and (3) appearance, smell and taste. Neophilics rated novel foods more favorably than did neophobics. Accumulating sensory experience (appearance, smell, taste) decreased liking for novel foods but increased liking for familiar foods. Verbal information generally increased liking for all samples. Liking and certainty of product identity were curvilinearly related for novel foods, but linearly related for familiar foods. Liking for products judged to closely resemble the test product predicted up to 64% of the variability in expected and actual liking. Eight weeks later, subjects rated one of the two novel foods higher than in the first exposure, but no other exposure effects were observed. Our data suggest that information (possibly via reduced uncertainty), resemblance to more familiar foods, and exposure contribute to reducing initially negative responses to novel foods; furthermore, neophobia decreases liking for novel foods similarly at all levels of sensory input (visual, smell and taste).

Epidemiology of American cutaneous leishmaniasis due to Leishmania braziliensis braziliensis

A five-year prospective study of cutaneous leishmaniasis in an endemic area of Brazil revealed an annual incidence of disease of 8.1 per 1000 inhabitants and a prevalence of 14.9%. The disease fluctuated as a series of mini-epidemics. Most disease occurred in individuals who were 10-30 years of age. Mucosal disease occurred in 2.7% of patients with primary lesions and occurred a median of six years after this lesion. Disease was more common in males, in those with either large or multiple antecedent skin lesions, and in those with incomplete antimony therapy for the primary lesions. An ELISA was positive in 85% of those tested during the first two years after the primary lesion and remained positive for five to 40 years in 27% of patients. Skin testing was positive in 96% of patients with recent lesions and remained positive in 70% of patients. All patients with mucosal disease had positive serological and skin tests.

Treatment and prophylaxis of Isospora belli infection in patients with the acquired immunodeficiency syndrome

Enteric infection with the protozoan Isospora belli is common in patients with the acquired immunodeficiency syndrome (AIDS) and causes severe diarrhea. I. belli responds well to treatment with trimethoprim-sulfamethoxazole, but there is a high rate of recurrence. To investigate the effect of long-term prophylaxis, we studied 32 Haitian patients with AIDS complicated by I. belli infection and chronic diarrhea. All were treated with trimethoprim (160 mg) and sulfamethoxazole (800 mg), given orally four times a day for 10 days; the patients were then randomly assigned to receive 500 mg of sulfadoxine and 25 mg of pyrimethamine weekly, 160 mg of trimethoprim and 800 mg of sulfamethoxazole three times a week, or placebo. Half of the patients (5 of 10) who received placebo had recurrent, symptomatic isosporiasis a mean of 1.6 months after the initial treatment. All 22 patients who received either trimethoprim-sulfamethoxazole or sulfadoxine-pyrimethamine remained asymptomatic. I. belli was identified in the stools of only one of these patients, who was receiving trimethoprim-sulfamethoxazole. The study medications were generally well tolerated but had to be discontinued in the cases of two patients because of severe pruritus. In 10 patients, the prophylactic regimen has been continued for a mean of 16 months without recurrent isosporiasis. We conclude that isosporiasis in patients with AIDS can be treated effectively with a 10-day course of trimethoprim-sulfamethoxazole and that recurrent disease can subsequently be prevented by ongoing prophylaxis with either trimethoprim-sulfamethoxazole or sulfadoxine-pyrimethamine.

Clinical manifestations and therapy of Isospora belli infection in patients with the acquired immunodeficiency syndrome

Isospora belli has recently been recognized as an opportunistic protozoan pathogen in patients with the acquired immunodeficiency syndrome (AIDS). Although I. belli rarely causes diarrhea in patients with AIDS in the United States, we have documented isosporiasis in 15 percent (20 of 131) of such patients in Haiti. The infection was associated with chronic watery diarrhea and weight loss that was clinically indistinguishable from disease caused by the related coccidia cryptosporidium. No demographic or laboratory data distinguished the patients with AIDS and isosporiasis from those with either cryptosporidiosis or other opportunistic infections. Neither I. belli nor cryptosporidium was detected in stool samples from 170 healthy siblings, friends, and spouses of the patients with AIDS. In all patients with isosporiasis, diarrhea stopped within two days of the beginning of treatment with oral trimethoprim-sulfamethoxazole. Recurrent symptomatic isosporiasis developed in 47 percent of the patients, but it also responded promptly to therapy with trimethoprim-sulfamethoxazole. We conclude that isosporiasis is common in Haitian patients with AIDS, and that it responds to therapy with trimethoprim-sulfamethoxazole but is associated with a high rate of recurrence.

Cell-mediated immunity in American visceral leishmaniasis: reversible immunosuppression during acute infection

Cell-mediated immunity was assessed in 14 Brazilian patients with acute untreated American visceral leishmaniasis (AVL) and in 11 healthy patients successfully treated 1 to 14 years previously. The diagnosis of AVL was established by demonstration of leishmania in bone marrow aspirates. The responsiveness of peripheral blood mononuclear cells to Leishmania chagasi antigens and phytohemagglutinin was studied in vitro. Soluble preparations of L. chagasi antigens were obtained from frozen-thawed promastigote cultures. L. chagasi antigen-stimulated lymphocytes from untreated AVL patients were unresponsiveness and incorporated a mean of 1.2 +/- 0.5 X 10(-3) cpm after a [3H]thymidine pulse. The cured AVL patients had 19.1 +/- 7.2 cpm, and 15 normal control subjects had 0.8 +/- 0.1 cpm. There were no differences in the response of controls and either untreated or cured AVL patients to phytohemagglutinin stimulation. Three of four untreated AVL patients responded to L. chagasi antigens when studied 2 to 4 weeks after therapy. The impaired response of lymphocytes from untreated AVL patients could not be attributed to either reduced numbers of circulating T cells or the inhibitory effect of monocytes or serum factors.