Zebrafish dax1 is required for development of the interrenal organ, the adrenal cortex equivalent.

Mutations in the human nuclear receptor, DAX1, cause X-linked adrenal hypoplasia congenita (AHC). We report the isolation and characterization of a DAX1 homolog, dax1, in zebrafish. The dax1 cDNA encodes a protein of 264 amino acids, including the conserved carboxy-terminal ligand binding-like motif; but the amino-terminal region lacks the unusual repeats of the DNA binding-like domain in mammals. Genomic sequence analysis indicates that the dax1 gene structure is conserved also. Whole-mount in situ hybridization revealed the onset of dax1 expression in the developing hypothalamus at approximately 26 h post fertilization (hpf). Later, at about 28 hpf, a novel expression domain for dax1 appeared in the trunk. This bilateral dax1-expressing structure was located immediately above the yolk sac, between the otic vesicle and the pronephros. Interestingly, weak and transient expression of dax1 was observed in the interrenal glands (adrenal cortical equivalents) at approximately 31 hpf. This gene was also expressed in the liver after 3 dpf in the zebrafish larvae. Disruption of dax1 function by morpholino oligonucleotides (MO) down-regulated expression of steroidogenic genes, cyp11a and star, and led to severe phenotypes similar to ff1b (SF1) MO-injected embryos. Injection of dax1 MO did not affect ff1b expression, whereas ff1b MO abolished dax1 expression in the interrenal organ. Based on these results, we propose that dax1 is the mammalian DAX1 ortholog, functions downstream of ff1b in the regulatory cascades, and is required for normal development and function of the zebrafish interrenal organ.

Availability of HIV care in Central America.

Central America is an area with a growing human immunodeficiency virus (HIV) epidemic, but with marked limitations in its health care infrastructure. Estimated adult HIV infection rates range from 0.20% in Nicaragua to 2.01% in Belize. Hospitals and clinicians with experience in HIV care exist mainly, if not only, in capital cities and principal economic centers. Nationally sponsored social security systems in each country consistently offer a wider range of services than do ministry of health systems. Estimated access to the social security system ranges from 0% in Belize and 10% of the population in Honduras to 95% in Costa Rica. Combination antiretroviral therapy is not available through the ministries of health and zidovudine is only sporadically available for prevention of perinatal transmission. Combination therapy is available through the social security system in the countries of Guatemala, Panama, and Costa Rica only. A wide variety of antiretroviral agents are available through private pharmacies in all countries except Belize. With the exception of Costa Ricans, most people with HIV infection in Central America have limited access to HIV-specific health services and limited or no access to antiretroviral agents.

Apical root resorption in patients treated with comprehensive orthodontics.

External apical root resorption (EARR) is a common--but seldom extreme--consequence of orthodontic treatment. Incisors are most at risk, perhaps because of their single roots and because they typically are moved farther than other teeth. We followed a cohort of patients (n = 153) treated with comprehensive orthodontics. EARR was scored on the upper incisors with a qualitative five-grade ordinal scale. There was no EARR at the start of treatment, but most (> 80%) exhibited slight-to-moderate EARR by the end of treatment (i.e., a loss of 1-2 mm). Cases treated with premolar extractions experienced more EARR because their incisors were retracted farther; however, the sum of the effects of patients' sex and age, and severity of the malocclusion, and the kind of mechanics used accounts for little of the overall variation in EARR. Instead, it appears that genetically-based inter-individual variation in susceptibility to EARR is the most influential factor. Research should be directed at understanding the biochemical nature of susceptibility so prospective patients can be screened to identify those at particular risk.

Screening of Costa Rican Trichilia species for biological activity against the larvae of Spodoptera litura (Lepidoptera: Noctuidae).

Crude methanolic extracts made from the twigs of 39 plant samples from six species of Trichilia collected in Costa Rica, were incorporated into artificial diet and fed to neonate Spodoptera litura larvae. All six plant species tested significantly reduced larval growth after 7 and 10 days. The most active species was T. americana, reducing growth, on average, to 3.9% of control at 1000ppm fresh weight. The least active, on average, was T. glabra. A twig extract of T. americana proved to be more active than wood, bark or leaf extracts, with the twig extract reducing growth of S. litura larvae by 50% (EC(50)) at a dietary concentration of 17.2ppm. When T. americana wood extract was incorporated into artificial diet (10, 25, 50 and 75ppm) and fed to S. litura larvae throughout larval development, growth was slowed and the final weight of pupae and adults was reduced. At higher extract concentrations (50 and 75ppm) larvae entered one or two supernumerary instars before pupation occurred. This was shown to be due to both starvation and to post-ingestive activity of the extract.

Digital reviews in molecular biology: approaches to structured digital publication.

MOTIVATION: It is widely appreciated that it is no longer possible for biomedical research scientists to keep up with as much of what is published in their field as they ought. One solution to this problem is to increase the efficiency of information use by moving away from the classical browsing model for scientific information dissemination towards an information on demand model which would allow researchers to access information quickly and efficiently only as they need it. The most common approach to this goal has been to use information retrieval technology to improve access to text databases of biomedical information. We are interested in exploring an alternative; encoding this information for storage in structured databases for efficient retrieval. RESULTS: Two small databases described here are test beds for development of structured digital publication software; the Tumor Gene Database, containing information about genes which are the sites for cancer-causing mutations, and the Mammary Transgene Database, containing information about expression of transgenes in agriculturally important animals. Both have been successfully searched by users and edited by curators via the World Wide Web.

Low-dose daily subcutaneous interleukin-2 in combination with highly active antiretroviral therapy in HIV+ patients: a randomized controlled trial.

PURPOSE: Previous studies with intermittent interleukin-2 (IL-2) therapy using intermediate and high levels of IL-2 have demonstrated significant increases in the CD4 + T cell count in HIV-infected patients. Intermittent regimens are amenable to outpatient use, but severe adverse events are frequently experienced with intermediate- and high-dose levels of IL-2. Therefore in this study, the effect of daily, subcutaneous low-dose IL-2 therapy on safety and immunological endpoints was investigated to determine whether immunological benefit could be achieved without toxicity in HIV-infected patients also receiving highly active antiretroviral therapy (HAART). METHOD: A total of 115 patients were enrolled in the trial. Fifty-six asymptomatic HIV-infected patients who had CD4 + T cell counts less than 300 cells/microL at screening and a stable HIV viral load received low-dose IL-2 (1.2 million IU [MIU]/m 2 beginning dose) once daily in conjunction with HAART (IL-2 group). Fifty-nine patients received HAART alone (control group). RESULTS: A dramatic effect of IL-2 on the natural killer (NK) cell population was observed with mean increases of 156 cells/microL in the IL-2 group compared to 19.93 cells/microL in the control group (p <.001). Additionally, IL-2-treated patients experienced a statistically significant increase in the mean percentage of CD4 + T cells (3.52% increase) when compared to control patients (1.33% increase) (p <.001). The expanded CD4 + T cell population was primarily of the naive phenotype, with mean increases of 4.53% for the IL-2 group and 0.31% for the control group (p <.001 for between-group difference). In addition, a higher proportion of IL-2-treated patients (67%) compared to control patients (33%) achieved increases of greater than 50% in the CD4+ T cell count (p =.08). Adverse events of grade 3 or grade 4 toxicity were infrequent in the current study and were substantially lower by comparison to those in studies of intermittent dose IL-2 therapy. Also, negligible changes in the HIV viral load from baseline to final measurement were observed in both groups. A trend toward a reduced number of modifications of antiretroviral therapy was apparent in the IL-2 group when compared to control patients. CONCLUSION: Daily, low-dose subcutaneous IL-2 therapy in conjunction with HAART is safe and well tolerated and is effective in expanding lymphocyte cell types including NK cells and naive T cells in individuals who have <300 CD4+ T cells.

Using statistical process control charts for the continual improvement of asthma care.

BACKGROUND: Home monitoring of lung function using simple, inexpensive tools to measure peak expiratory flow rate (PEFR) has been possible since the 1970s. Yet although current national and international guidelines recommend monitoring of PEFRs via traditional run charts, their use by both patients and physicians remains low. The role of statistical process control (SPC) theory and charts in the serial monitoring of lung function at home were explored and applied to the direct care of patients with asthma. The method represents an integration of collective professional and improvement knowledge with the related disciplines of continual improvement, SPC, system thinking/system dynamics, paradigms, and the learning community/organization. CASE STUDIES: Use of PEFR control charts for four patients cared for at the Asthma-Allergy Clinic and Research Center (Shreveport, La) is described. The key to good asthma control is the ability to optimize lung function by reducing the variation between serial lung function measurements and thereby generate a safe range of function. Knowledge of the type of variation (special cause or common cause) in the system helps in focusing clinical decision making. Case 4, an 11-year-old boy, for example, shows how control charts were used to learn the effects of a new inhaled corticosteroid. Comparison of the last 14 days of baseline and the last 14 days of open label use of the inhaled corticosteroid showed an obvious improvement in actual PEFR values--which a run chart or comparison of means would have easily demonstrated. The control chart showed that this child's care process at baseline was functionally at risk for severe asthma (46% personal best) and that the effect of the new medication not only elevated the mean function but shifted the range of function from 46%-72% personal best to 78%-102% personal best. At this new range of function the patient's system of care was not capable of delivering values that are at risk for severe asthma. Unless the range of function the change in care is capable of producing is specifically quantitated, misinterpretation of improvement data can occur. DISCUSSION: Developing the concept of the PEFR control chart involved examining and challenging traditional mental models for monitoring PEFR at home in the care of asthma, acquiring a better understanding of the workings of dynamic systems and with system thinking, and sharing what was learned with patients and seeking their input. CONCLUSIONS: The PEFR control chart employs an interesting statistical platform that enables the integration of knowledge of serial measurements and knowledge of the variation between those measurements into a tool with which to better assess the asthma care process being followed. This tool provides clinical insights, practical knowledge, and opportunities unavailable to patients and physicians via traditional PEFR charting.

A managed care organization's attempt to increase influenza and pneumococcal immunizations for older adults in an acute care setting.

OBJECTIVE: Among the high risk groups for complications from influenza and pneumococcal disease, individuals aged 65 and older hospitalized within the previous year represent the group at highest risk. Studies have demonstrated that targeting hospitalized patients aged 65 and older for immunization before hospital discharge can be successful. This study addressed the efficacy of such a program within a managed care organization to immunize this highest risk group. DESIGN: A cross-sectional study. SETTING: Oxford Health Plans, a major managed care organization in New York serving a large Medicare population. PARTICIPANTS: A total of 106 Primary Care Physicians caring for 153 patients aged 65 and older, who were hospitalized in one of 10 high volume hospitals during October and November of 1996. Nine of these facilities were located in New York and one was in New Jersey. INTERVENTION: Patients aged 65 and older admitted to any of the 10 hospitals were identified daily. A fax was sent to each patient's primary care physician explaining the program and requesting that he/she administer influenza and/or pneumococcal vaccine to his/her patient before hospital discharge. Literature references citing past successful programs were included in the fax. MEASUREMENTS: Measurements included medical record documentation of influenza and pneumococcal immunization, both ordered and given, for the individual member before discharge; patient age; sex; and primary and secondary diagnoses. Physicians were sent follow-up questionnaires to determine reasons for not vaccinating. RESULTS: A total of 206 patients were admitted during the eligible time period. One hundred fifty-three hospitalized patients (average age = 74 years) participated. The median length of stay among this study population was 5 days (range, 1-63 days). The distribution of the median length of stay for the 25th and 75th percentiles was 3 and 9 days. The rate for influenza and pneumococcal immunization, both ordered and given, before hospital discharge was 1.96% for the influenza vaccine (n = 3) and .65% for the pneumococcal vaccine (n = 1), respectively. Results of a follow-up survey mailed to all physicians (n = 106) with eligible members in the study indicated that the most frequent reasons for not vaccinating included: patients were vaccinated before admission, patients were not stable enough to be vaccinated before discharge, and the acute care setting is not appropriate for vaccination. Response rate of 58% (n = 61) was achieved with an initial mailing and one follow-up telephone call to all previous nonresponders. Some physician survey responses do not correlate with data obtained from retrospective patients' claims analysis. CONCLUSION: Well-coordinated and timely attempts to encourage primary care physicians to immunize patients 65 years and older before hospital discharge were unsuccessful in our study. Rather than working with physicians, it may be that managed care organizations should work directly with hospitals to implement influenza and pneumococcal immunization programs.

Weight loss and disease progression in HIV infection.

Weight loss and malnutrition continue to be important issues that clinicians face when treating patients with HIV infection. In addition to specific clinical consequences, weight loss in these patients is linked to a greater risk of death and opportunistic complications. A loss of as little as 5% to 1-% of baseline body weight can be associated with a risk of death that is 2.5 times that seen in patients with HIV infection who do not lose weight. Furthermore, weight loss in patients with HIV infection can increase the risk of individual opportunistic infections by as much as 61% to 176%. Future studies may help define the prognostic implications of lipodystrophy and changes in body cell mass in patients with HIV who are taking antiretroviral therapy.

The breast cancer gene database: a collaborative information resource.

The Breast Cancer Gene Database (BCGD) is a compendium of molecular genetic data relating to genes involved in breast cancer, and which is freely available via the World Wide Web. The data in BCGD is extracted from the published biomedical research literature and stored as a collection of 'Facts', which in turn are collected into topical categories organized by gene. This organization facilitates quick searches and rapid retrievals of specific data such as gene characteristics, functions and role in oncogenesis, and is an important factor allowing for continuous updates. BCGD can be searched either by gene name or keyword. Data is deposited and retrieved from the database through a set of interactive Web forms, making it both platform-independent and universally accessible in facilitating worldwide collaborative authoring of the database. Data in BCGD is linked to other on-line resources such as Entrez, GeneCards and On-Line Mendelian Inheritance in Man. BCGD is located at http://mbcr.bcm.tmc.edu/ermb/bcgd/bcgd.html.

Randomized, controlled trial of caloric supplements in HIV infection. Terry Beirn Community Programs for Clinical Research on AIDS.

OBJECTIVE: To compare the efficacy of three nutritional regimens in the prevention of weight loss. DESIGN: A three-arm randomized controlled trial with primary outcome measure percent change in weight over four months. PATIENTS: A total of 536 patients with CD4 count <200 cells/mm3 and stable weight, defined as <5% weight loss as determined by a weight measurement 3 to 6 months before randomization were recruited at fourteen administrative units in the United States, each unit consisting of multiple primary care sites. INTERVENTION: The three arms were 500 kcal daily of caloric supplement with peptides and medium-chain triglycerides plus a multivitamin and mineral supplement, 500 kcal of a caloric supplement with whole protein and long-chain triglycerides plus a multivitamin and mineral supplement, and a multivitamin and mineral supplement only. RESULTS: There were no significant differences among the three regimens in the percent change in weight (p = .74) and body cell mass (p = .63). On average, 65% of the recommended 500 kcal/day of caloric supplements containing peptides with medium-chain triglycerides and 82% of the 500 kcal/day of the caloric supplement containing whole protein and long-chain triglycerides were consumed. CONCLUSIONS: Caloric supplements do not promote increases in average weight or body cell mass in weight-stable, HIV-infected adults beyond that offered by a multivitamin and mineral supplement.

Weight loss as a predictor of survival and disease progression in HIV infection. Terry Beirn Community Programs for Clinical Research on AIDS.

Severe weight loss in HIV is associated with decreased length of survival. It is unclear whether mild weight loss is associated with an increased risk of death or opportunistic complications of HIV. Participants in four interventional studies (n = 2382) conducted by a community-based clinical trials network were evaluated for percentage change in weight during their first 4 months in the study. Proportional hazards models were performed for the occurrence of opportunistic complications and death subsequent to the 4-month visit. The relative risk of death and opportunistic complications for those with 5% to 10% weight loss over 4 months was 2.22 (p < .001) and 1.89 (p < .001), respectively, and 1.26 (p < .01) and 1.19 (p < .01) among those who lost 0% to 5% of their body weight, respectively, when compared with those with no weight loss. Among those who lost 5% to 10% of their body weight, the relative risk of individual opportunistic complications increased significantly, including Pneumocystis carinii pneumonia (PCP) (1.61; p < .01), cytomegalovirus (CMV) (2.33; p < .001), and Mycobacterium avium complex (MAC) (1.81; p < .01). As little as 5%t weight loss over a 4-month period is associated with increased risk of death and opportunistic complications in HIV. A weight loss of 5% to 10% is also associated with an increased risk of individual opportunistic complications.

QS-21 and QS-7: purified saponin adjuvants.

QS-21 and QS-7 are two adjuvant-active saponins that can be obtained in high purity from Quillaja saponaria Molina extracts. QS-21 is a highly characterized compound and is known to be a potent adjuvant for antibody and CD8+ CTL response to subunit antigens. Less is known about the activity and structure of the hydrophilic saponin QS-7. Hence, we have carried out a detailed structural and immunological characterization. As with QS-21, QS-7 was shown to be a 3,28-O-bisglycoside quillaic acid, with some differences being a higher degree of glycosylation and a considerably shorter fatty acyl unit in QS-7. These differences were correlated to a lower lytic activity against sheep red blood cells. Different doses of QS-7 were evaluated for stimulation of immune response to the antigen ovalbumin, given three times by subcutaneous route to C57BL/6 mice. QS-7 doses of 40 micrograms or higher were shown to induce a strong CD8+ CTL response reproducibly against E. G7-OVA targets (similar to that induced by a 5-10 micrograms dose of QS-21). QS-7 (at doses above 5 micrograms) was also shown to stimulate CTL against peptide 18 of HIV-1IIIB gp120 after three immunizations of Balb/c mice with recombinant gp120 and different doses of QS-7. These data suggest that a hydrophilic saponin with low lytic activity can stimulate MHC Class I CTL responses although a higher minimum dose may be required for some antigens.

Human immunodeficiency virus in the health care setting.

Dr. Wheeler reviews the mechanisms of HIV infection and discusses procedures and situations that place health professionals at risk. Prevention of HIV transmission, institutional management of occupational exposure, and postexposure prophylaxis are addressed.

Structure and expression of the mouse casein gene locus.

The analysis of yeast artificial chromosomes (YACs) containing the complete mouse casein gene locus revealed the presence of five casein genes, alpha-, beta-, gamma-, delta-, and kappa-casein, in this order, in the locus. The alpha- and beta-casein genes are only 10 kb apart and have convergent transcriptional orientations. The distance between the beta-casein gene and the alpha s2-like gamma-casein gene is about 70 kb, and these genes have divergent transcriptional orientations. The gamma- and delta-casein genes, both encoding a alpha s2-like casein, are linked within 60 kb and convergently transcribed. The kappa-casein gene is located about 100 kb from the delta-gene. Except for the presence of the delta-casein gene, the organization of the mouse casein locus resembles that of the bovine locus, including the transcriptional orientation of the genes. In contrast to the other casein genes, which are strongly induced at mid-lactation, expression of the delta-casein gene is abruptly induced upon parturition. Comparative analysis of alpha s2-like sequences from various species suggests that the ancestral alpha s2-like gene duplicated around the time of radiation of the rodent and artiodactylid ancestors.