Study of lymphocyte subpopulations in contact dermatitis by sensitization to chrome and/or nickel

Contact dermatitis is a hyperergic reaction mediated predominantly by T lymphocytes in which the target tissue is the skin. In this way and taking as a starting point that contact dermatitis is a reaction typically mediated by T lymphocytes, our aim is to study the possible existence of an unbalance between the lymphocyte subpopulations OKT-4+ and OKT-8- (T mu and T gamma) in comparison to a normal population and if, on the other hand, any of these subpopulations are involved in the increase of lymphocytes that form E active rosettes. We can see that there are no significant variations with regard to the number and function of the lymphocyte populations in individuals with contact dermatitis when we compare them to a control group. On the other hand, we consider it very important to emphasize that we have failed to detect differences in the parameters of lymphocyte populations and subpopulations studied before and after contact with the causal antigen responsible for the cutaneous condition.

Family studies of the HLA system in acute post-streptococcal glomerulonephritis

Eighteen families (67 siblings) of index cases with acute post-streptococcal glomerulonephritis (APSGN) were typed for HLA-A,B,C,DR antigens. Twenty cases of clinical nephritis and 10 cases of asymptomatic disease with detected among the sibships. In eight families with more than one affected individual comprising 18 sib pairs random segregation of paternal and maternal HLA haplotypes was found (0.5 less than p less than 0.06), but some antigens (CW1, DR3) showed deviation from the expected 1:1 ratio in affected and nonaffected siblings in backcross families. We had previously noticed the existence of Mendelian recessive ratios in APSGN but in the absence of clear evidence for a dominant or recessive mode of inheritance for a putative APSGN susceptibility gene(s), pedigree data were analyzed twice for linkage with HLA using the two genetic models. The data obtained, although not sufficient to reject the hypothesis of linkage, provide no support for it. Comparison of the frequency of 61 HLA antigens among 42 unrelated APSGN patients and 109 controls, showed that HLA-DRW4 is more frequent among the former (pc = 0.0500).

Crystals of polyglycine in the beta form

Well-defined lamellar crystals of polyglycine I (the beta modification of polyglycine) have been grown from a solution of a sample of 5000 molecular weight. The crystals are elongated and have an average thickness of 40 to 50 A. The unit cell is monoclinic and the crystals have a twined structure. Electron diffraction reveals that the polypeptide chains are normal to the basal plane of the crystals and that the hydrogen bonds are parallel to their long sides. From these data we conclude that crystals of polyglycine I have a folded beta structure.

Some variables of the craniofacial complex in a Venezuelan population of Negroid ancestry

A total of 226 individuals (101 males and 125 females), from La Sabana, a Venezuelan Negroid isolate, with ages between 8 and 60 years, were studied in order to characterize the population for its craniofacial variables and to study the behavior of these variables in relation to age and sex. The variables studied were grouped in three categories: direct cephalometric variables, which included 6 measurements taken directly on the individuals; indirect cephalometric variables, which included 18 measurements (9 angular and 9 linear), taken on lateral head films; and dental variables, which included 9 measurements taken from dental models. In general the direct variables showed the lowest coefficients of variation (CV), suggesting homogeneity within this sample. They were followed by the dental and the indirect variables, which had the highest CV values. In order to detect age and sex effects on the variables, sex and age group comparisons were performed with Student t tests. A greater proportion of significant differences were found among the direct variables, indicating that age and sex have more influence on this group of variables than upon the other two. Comparisons of our sample from La Sabana, with samples from African Negroid, Caucasoid, and Amerindian population show that La Sabana individuals have a craniofacial pattern basically Negroid, as we expected, although some contribution from Caucasoides and especially Amerindians is also suggested in our data.

Evaluation of short stature in children

Within a year 429 children referred for short stature have been evaluated. The age at consultation ranged from 5 months to 17 1/2 years. Healthy but small children came at 5 to 7 and 10 to 13 years, while those with different pathologies attended the clinic at all ages. The stature of 43% of the investigated children ranged within normal limits (till -2 SDS), while 57% had a small stature. 68% of the children could be considered healthy, 32% had different endocrine and nonendocrine diseases responsible for their growth retardation. Retarded bone age (greater than 2 SD below the mean) was observed in 65% of the significantly short but otherwise healthy children and in only 28% of the healthy children with heights above -2 SD. Extreme short stature was mainly associated with a recognized disease of chronic and genetic origin, low birthweight and malnutrition. The high incidence of hypopituitarism (15 patients) is due to the fact that this study was performed in an endocrine clinic.

Experimental endocarditis caused by Streptococcus sanguis: single and combined antibiotic therapy

The effectiveness of penicillin G, fosfomycin, and cefoxitin alone and in combination was studied in vitro and in the treatment of left-sided Streptococcus sanguis endocarditis in rabbits. In vitro, the combinations penicillin G plus fosfomycin, penicillin G plus cefoxitin, and fosfomycin plus cefoxitin were synergistic or partially synergistic for S sanguis. Therapy with the combinations was more effective in eradicating the species from cardiac vegetations that was that with each antibiotic used alone.

Fosfomycin penetration into the cerebrospinal fluid of patients with bacterial meningitis

A comparative study was made of the penetration of fosfomycin, penicillin G, ampicillin and chloramphenicol into the cerebrospinal fluid of patients with meningitis treated with combinations of fosfomycin and one of the other three antibiotics. Minimal inhibitory concentrations and in vitro interaction of these antibiotics against Streptococcus pneumoniae and Neisseria meningitidis strains were determined. 90-96.5% of these strains were sensitive to penicillin G, 95-96.5% to ampicillin, 85-100% to chloramphenicol and 90-100% to fosfomycin. Fosfomycin shows a more marked synergism with penicillin G or ampicillin than with chloramphenicol against both bacterial species. The percentages of penetration into the cerebrospinal fluid were: chloramphenicol, 32%; fosfomycin, 25.7%; ampicillin, 15.9%, and penicillin G, 7.9%. The clinical results show that the combination of fosfomycin + penicillin G or fosfomycin + ampicillin can be an alternative in the treatment of meningitis produced by moderately susceptible strains of S. pneumoniae and N. meningitidis to penicillin G and ampicillin.

[Hepato-splenic scintigraphy in finding indications of bacterial endocarditis. Preliminary report]

Hepato-splenic scintigraphy with 99mTc-S-colloid was performed in twelve patients with bacterial endocarditis. These images showed that the size of the liver varied from normal to a severe hepatomegaly, depending on the presence of congestive heart failure. Intrahepatic distribution of the radiocolloid was slighty irregular in all cases. The spleen was conspicuously enlarged, and showed irregular distribution of the radiopharmaceutical. In some cases intrasplenic concentration defects caused by infarcts, abscesses or cysts, were observed. The relative uptake of radiocolloid by the spleen, varied from hypo- to hyperconcentration according to the degree of lymphoid hyperplasia caused by the infection. In two cases, both with congestive heart failure, concentration of the radiocolloid was evident in the bone marrow. The scintigraphic pattern observed in these patients with bacterial endocarditis can be easily differentiated from that caused by only congestive heart failure, which is similar to the observed in patients with cirrhosis of the liver and/or portal hypertension.

Comparing the "family set" approach to estimate heritability with other conventional estimators: a Monte Carlo simulation

A Monte Carlo simulation is performed to study the distribution of the family set estimators of heritability and to compare their performance with that of some conventional estimators used in human genetics. Comparisons of statistical properties among the two family set estimators (one based on the partial regression coefficients of the index's values on those of sib and cousin, respectively, and one based on the variances of the differences between the phenotypic values of index and cousin and of index and sib) and the three conventional estimators (one based on regression of index value on midparental value, another based on the sib-sib correlation, and the last one based on the index-cousin correlation) are also made under two genetic models.