Connectivity patterns in tuberculosis and leprosy patients are indistinguishable from that of healthy donors

Connectivity, the self-defined interactions between antigen-recognising molecules in a network system can in part be assessed by measuring the reactivity of a given serum against an ordered set of immunoglobulin (Ig)G F(ab')2 fractions, separated by means of isoelectric focusing so that, the serum reactivity against the whole set of fractions defines a characteristic pattern of connectivity. Deviations from the normal condition (healthy donors) have so far been documented for two autoimmune diseases: systemic lupus erythematosus (SLE) and pemphigus vulgaris, as well as for human immunodeficiency virus (HIV)-1 infection. We tested here if bacterial infections lead to alterations in connectivity. In addition, we wanted to test if two antigenically related bacteria would produce similar or otherwise distinctive connectivity patterns. Connectivity analysis was applied on the sera from tuberculosis and leprosy patients and the sera from healthy donors were used as control. No statistically significant differences between the three groups studied were found. These results have implications for theories that set the origin of autoimmune diseases in microbial infections. To the best of our knowledge, this is the first attempt to analyze the connectivity status in bacterial infections.     

National contaminant biomonitoring program: Residues of organochlorine chemicals in U.S. Freshwater Fish, 1976–1984

The U.S. Fish and Wildlife Service periodically determines concentrations of organochlorine chemicals in freshwater fish collected from a nationwide network of stations as part of the National Contaminant Biomonitoring Program (NCBP, formerly a part of the National Pesticide Monitoring Program). From late 1984 to early 1985, a total of 321 composite fish samples were collected from 112 stations and analyzed for organochlorine chemical residues. The mean concentrations of total DDT did not change from 1980–81 to 1984, following a period of steady decline through the 1970's; however, the mean concentrations ofp,p-DDT declined significantly. The most persistent DDT homolog (p,p-DDE) was detected at 98% of the stations sampled in 1984, and constituted 73% of total DDT residues, up from 70% in 1974–79. Collectively, these findings indicate a low rate of influx and continued weathering of DDT in the environment. Residues of polychlorinated biphenyls (PCBs) also remained widespread, but a significant downward trend in total PCBs was evident, and early eluting PCB components were present at fewer stations than in the past. Mean concentrations of dieldrin have not changed since 1978–79; concentrations remained highest in Hawaii and in the Great Lakes. Toxaphene concentrations declined from 1980–81 to 1984, especially in the Great Lakes, and the incidence of toxaphene declined from 88% of the stations sampled in 1980–81 to 69% in 1984. Mean chordane concentrations did not change from 1980–81 to 1984, following a period of decline; however,trans-nonachlor replacedcis-chlordane as the most abundant component, suggesting a lower influx of chlordane to the aquatic environment. Residues of other organochlorines—mirex, pentachloroanisole (PCA), benzene hexachloride (BHC) isomers, endrin, heptachlor, hexachlorobenzene (HCB), and Dacthal^® (DCPA)—were either found at relatively few (<25%) of the stations sampled in 1984 or were characterized by relatively low concentrations. In general, organochlorine concentrations were lower in 1984 than at any time reported previously.     

Pristane (2,6,10,14-Tetramethyl-pentadecane) inhibits disease progression in Leishmania-infected Balb/c mice

The course of Leishmania infection in pristane-primed BALB/c mice infected with either Leishmania major or Leishmania donovani was examined. Pristane-primed L. donovani infected mice had spleen parasite-loads that were 13 times less than controls. Likewise pristane-primed L. major infected animals had significantly smaller footpad lesion areas than controls. Pristane-primed mice had an atypical haematology compared to controls. To the best of our knowledge, this is the first report to demonstrate that pristane inhibits progression of disease in Leishmania-infected BALB/c mice.     

Screening of metal ion chelators against Leishmania donovani-infected Syrian hamsters

Leishmania donovani-infected Syrian hamsters were treated intraperitoneally with 0.23 mmoles/kg/day of EDTA, EGTA, HEEDTA and 100 mg/kg/day of Pentostam R. The control group received 0.1 ml of phosphate buffered saline. After 30 days of treatment, the animals were sacrificed. Of the Pentostam-treated animals, 5 out 6 had negative spleen cultures, while all the chelator and PBS-treated ones yielded parasites. While all the Pentostam-treated animals had negative bone marrow cultures, only 1 out of 6 HEEDTA-treated hamsters yielded parasites. Spleen, liver and bone marrow parasite- loads calculated from chelator-treated animals were consistently significantly higher than for Pentostam-treated animals. These results suggest that although metal ion chelators have some antileishmanial potential, their in vivo activity against L. donovani is low compared to Pentostam.     

The Uniqueness of Child and Youth Care: A Personal Perspective

The author draws upon 30 years of experience in the child and youth care field, personally carrying a dual diagnosis as a professional child and youth care worker and a professional social worker for most of that time. A definition of child and youth care is offered, and differences in focus and emphasis within the two disciplines are explored. Two underlying paradigms are suggested as contributing to the tensions apparent between the professions internationally, and the author concludes that the continuing struggle to develop a free-standing profession of child and youth care needs to be vigorously pursued because competent child and youth care workers are good for children and play a unique role in their lives.     

Effects of environmental factors on the number of emergency admissions to the Hospital Complex Juan Canalejo in La Coruña: creation of a prediction model

BACKGROUND: This study is aimed at establishing the possible associations between the number of admissions through the emergency room at the "Juan Canalejol" Hospital in Corunna in 1994-1994 due to organic, circulatory and respiratory reasons and the weather variables introduced as being exogenous for the purpose of preparing a prediction model. METHODS: The Box-Jenkins methodology is used for obtaining univariate ARIMA models of the time-based series taken into consideration. Cross-Correlation Functions (CCF's) are established among the series of residuals which afford the possibility of establishing weights and lags among the variables for a subsequent modeling by means of multivariate ARIMA models which include environmental variables. RESULTS: The emergency admissions for organic reasons significantly increase 0-2 days following a rise in temperature. The admissions due to respiratory ailments are associated with drops in temperature with 10-14 lags, whilst the admissions for circulatory reasons increase significantly due to long-lasting spells of hot weather (10 lags). For people over age 65, significant increases in emergency admissions for circulatory reasons are also recorded with cold snaps. The multivariate ARIMA models that take into account the effect of environmental variables provided the best adjustment for all of the admissions variables. CONCLUSIONS: The number of emergency room admissions at the "Juan Canalejo" Medical Center Complex in Corunna due to organic, respiratory and circulatory causes shows a seasonal behavior pattern. The admissions for respiratory reasons are associated with a drop in temperature, whilst the admissions for circulatory reasons are affected fundamentally by hot weather, although also by cold weather as regards people over age 65. The multivariate ARIMA models including climate-related variables provide a system for predicting admissions in terms of said variables that can be useful from the standpoint of hospital management.     

Smoking: attitudes of Costa Rican physicians and opportunities for intervention.

The aim of this study was to obtain information, using a written questionnaire, on the knowledge, smoking behaviour, and attitudes of Costa Rican physicians about smoking as a health issue. A random sample of 650 physicians was chosen from a list of active physicians; 287 of them were covered by survey between August 1993 and October 1994, and 217 (76%) responded with data for the study. While 40% of the physicians who participated were ex-smokers, 19% were current smokers; 67% of these two groups combined reported smoking in the workplace. Only 49% believed that physicians could be a nonsmoking role model; the majority (87%) had asked patients about their smoking status. The only cessation technique consistently used (90%) was counselling about the dangers of smoking. Measures such as setting a date to quit smoking and nicotine replacement were rarely recommended (< or = 2%). Nearly all the physicians (99%) considered smoking to be a major health issue. These results showed a high prevalence of smoking among Costa Rican physicians, with little recognition of the need for them to set an example as a role model. While they were knowledgeable about the health risks of smoking, they did not recommend any of the proven techniques to help their patients to quit smoking. A clear consensus for more strict tobacco regulation exists, but to date little has been done to act on this.     

Interaction of ivermectin with γ-aminobutyric acid receptors in Trichinella spiralis muscle larvae

The value of the γ-aminobutyric acid (GABA) receptor of nematodes as a target for ivermectin's mode of action remains unclear. Using binding assays, we examined extracts from Trichinella spiralis muscle larvae for the presence of [³H]-ivermectin and [³H]-GABA binding sites. Tissue preparations displayed affinity binding sites for [³H]-ivermectin with a dissociation constant (K _d) of 83 nM and a receptor density (B_max) of 145 fmol/mg protein. We also identified a specific [³H]-GABA binding activity with a K _d of 1.2 μM and a B_max of 4.78 pmol/mg protein. In competition studies, ivermectin was found to be a competitive inhibitor of specific [³H]-GABA binding activity with an inhibition constant (K _i) of 3.39 nM, suggesting that GABA receptors could be implicated in the mechanism of action of ivermectin in nematodes. Received: 7 August 1998 / Accepted: 22 September 1998