Biomedical subjects
Publications and source records attributed to H Steger.
One case of a bilateral idiopathic slipped capital femoral epiphysis--"slipped epiphysis"--in a cat is described. The similarities and the differences between the cases in human and small animal medicine concerning the incidence, the hypotheses of the pathogenesis and the treatment options are discussed.
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Hemoglobin E (codon 26 GAG-->AAG) and codon 17 nonsense (AAG-->TAG), two clinically important mutations of the beta-globin gene, are common in Southeast Asia. The detection of these mutations using allele-specific PCR is described. Together with the previously reported method for the detection of the common Southeast asian codon 41-42 frameshift mutation (del CTTT), it is possible to identify the vast majority of clinically important beta-globin gene mutations in Southeast Asian populations by means of nonradioactive methods.
Subcutaneous recombinant human erythropoietin (rHuEpo) treatment of renal anemia was performed in four boys and eight girls on CAPD, aged 0.8-12.5 (mean 7.4) years. In contrast to previous studies, our therapeutic goal was not set with a hematocrit of 30% but with full correction of anemia. Following a maximum weekly rHuEpo dosage of median 120 (range 100-240) IU/kg body weight, hematocrit increased in 10 children from 24 (14-29)% within 12 (4-17) weeks to 40.1 (33.5-48.4)%. The weekly increase in hematocrit was 1.27 (0.5-3.1)%. The corrected reticulocyte count increased from 1.3 (0.7-1.8)% to 2.3 (1.4-3.9)% within 4 (2-6) weeks. Eight children fulfilled the protocol; six with an uncomplicated course were able to maintain a hematocrit of 37.1 (35.1-42.7)% with only one sc medication per week of approximately two-thirds of their highest weekly rHuEpo dosage. No serious adverse effect of rHuEpo therapy was observed.
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In 30 children with renal allografts the diagnostic validity of pulsed Doppler (PD) versus colour coded Doppler (CD) sonography was assessed prospectively. 46 PD examinations were performed calculating the resistive index (RI) in the segmental arteries in comparison to 46 CD scans, where renal blood flow throughout the grey-scale image was displayed. In addition, point-spectral analysis with calculation of the RI was also performed on the CD scans. The time for examination ranged from five to ten minutes for the PD and from three to five minutes for the CD study. Concordant findings for the PD and CD technique were generally obtained (normal blood flow pattern on PD-excellent visualization of renal blood flow on CD, reduced or reversed diastolic flow on PD-poor visualization of renal blood flow on CD). There was close correlation of the RI values obtained by the PD and CD scans. CD sonography facilitated point-spectral analysis in shortening the time for examination. The ability to visualize focal hemodynamic alterations provided a higher diagnostic accuracy in comparison to PD sonography.
In routine analysis for immunoglobulin light chains in pediatric diagnostics, the age-related reference intervals for serum kappa (kappa) and lambda (lambda) light chains were evaluated in 1543 healthy subjects (newborns to age 16 years, including 168 premature infants). Light-chain analysis was performed by rate nephelometry. IgG, IgA, and IgM were measured simultaneously, and heavy- and light-chain differences were calculated for control purposes. Results for IgG, IgA, and IgM generally agreed with reference intervals reported in the literature. kappa showed age-related changes comparable with changes in IgG concentrations, whereas lambda showed moderate fluctuations. The kappa/lambda ratio showed an almost linear increase with age, starting with 0.97 at four months and reaching the highest value of 2.21 at 15 years (mean values). Preterm infants presented with markedly low serum concentrations of IgG and corresponding light chains but with adult-type kappa/lambda ratios because of the maternal-origin IgG.
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Urinary tract infections (UTI) in children are common. In the case of high grade vesico-ureteric-renal reflux (VUR) or urinary tract obstruction the abnormality may lead to end-stage renal failure. An early evaluation and adequate therapy after UTI are mandatory. Between 1980 and 1987 we evaluated 63 children with VUR. The symptoms of UTI are variable and age-dependent. Only in 13% of the children the urinary tract was evaluated after their first UTI. In 70% of the cases there were more than 1, mostly multiple UTI. The remaining 17% were admitted for other reasons. The relation boys to girls was 1:2. In boys the diagnosis of VUR was made earlier than in girls: 57% of boys and 17% of girls in their first year of life. In 24% of the boys and in 36% of the girls VUR was found between the 5th and 15th year of life. In the case of high grade reflux (IV-V) the kidneys showed heavy damage, loss of function and hypertension at the time of diagnosis. The aim must be early diagnosis and adequate therapy to prevent avoidable damages.
Six out of 14 chronically hemodialysed children with significantly decreased serum carnitine levels were substituted with L-carnitine (15-30 mg/kg/day-Biocarn) up to normal and above normal carnitine levels. None of these patients were digitalised. During the time of investigation plasma carnitine levels were investigated monthly and, simultaneously, three echocardiographic parameters in M-mode were quantitatively und qualitatively determined: shortening fraction (SF-%), ratio of left ventricular pre-ejection/ejection time (LVPT/LVET) and velocity of circumferential fibre shortening (Vcf). Carnitine substitution produced measurable changes in echocardiographic parameters, and a significant quantitative improvement in left ventricular function and performance: after 6 months of carnitine substitution a 24% improvement was seen, after 18 months a 44% mean improvement. No side effects of carnitine were observed; the compatibility was good. Beside these positive effects all patients reported decreased dialysis-associated spasms and polyneuropathic symptoms and increased somatic ability.
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Two forms of a DNA polymerase have been purified from microplasmodia of Physarum polycephalum by poly(ethyleneimine) precipitation and chromatography on DEAE-Sephacel, phosphocellulose, heparin Sepharose, hydroxyapatite, DNA-agarose, blue-Sepharose. They were separated from DNA polymerase alpha on phosphocellulose and from each other on heparin-Sepharose. Form HS1 enzyme was 30-40% pure and form HS2 enzyme 60% with regard to protein contents of the preparations. Form HS2 enzyme was generated from form HS1 enzyme on prolonged standing of enzyme preparations. The DNA polymerases were obtained as complexes of a 60-kDa protein associated with either a 135-kDa (HS1) or a 110-kDa (HS2) DNA-polymerizing polypeptide in a 1:1 molar stoichiometry. The biochemical function of the 60-kDa protein remained unknown. The complexes tended to dissociate during gradient centrifugation and during partition chromatography as well as during polyacrylamide gradient gel electrophoresis under nondenaturing conditions at high dilutions of samples. Both forms existed in plasmodia extracts, their proportions depending on several factors including those which promoted proteolysis. The DNA polymerases resembled eucaryotic DNA polymerase beta by several criteria and were functionally indistinguishable from each other. It is suggested that lower eucaryotes contain repair DNA polymerases, which are similar to those of eubacteria on a molecular mass basis.
At the turn of the century, reports on a coincidence of pineal tumors and precocious puberty in man initiated a host of animal experiments. Results of these experiments ultimately revealed a modulating effect on sexual maturation and on gonadal activity in several species, brought about by the pineal hormone melatonin (aMT) and particularly its circadian secretion pattern. In addition, it renewed interest in a possible interaction of the pineal and human sexual function. The introduction of specific and precise aMT assays provided exact evaluation of the circadian aMT secretion pattern in adults. Despite considerable efforts, however, a precise characterisation of this pattern has not yet been achieved in children. In a first step we examined single day- and nighttime serum samples from 280 subjects of all ages. aMT levels were low during early infancy, increased to their highest values around 1 to 3 years and dropped progressively by 75 percent until young adulthood, when they remained fairly stable. Thus, the pattern of aMT levels is the reverse of that of gonadotropin levels or gonadal activity in humans. Whether there is a causal relationship between the activity of the pineal gland and the hypothalamo-pituitary-gonadal axis in humans or whether the described negative correlation in the activity of both glands is purely coincidental remains to be clarified.
The reproduction situation of swine is considerably affected by embryonic foetal death. Reduction of loss of that origin, therefore, would open up palpable reserves. There is general agreement to the effect that the period close to implantation and the entire first month of gravidity make for the most critical phase of intra-uterine development. Proper mutual adaptation of progesterone and oestrogen levels are among the important prerequisites for favourable implantation conditions. However, fertility of swine was not always enhanceable by administration of progesterone and oestrogen. Tests of laboratory animals have shown that there are additional hormones and control mechanisms, on top of progesterone and oestrogen, which are involved in regulation of the implantation process. For example, higher prostaglandin F2 alpha concentrations in the blood and endometrial tissue of mammals in early gravidity seem to have adverse effects on implantation. The possibility is considered in this paper to eliminate such interference effect of prostaglandin by application of prostaglandin synthetase inhibitors.
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The highest pregnancy rate as well as most of all implantates and lowest foetal loss were recorded from the prostaglandin F2 alpha-(PGF2 alpha)-group (84, 84, and 16 per cent), while values following progesterone/oestrone and acetylsalicylic acid treatment were below those obtained from the controls. The highest number of normally developed (97 per cent) and the lowest number of degenerated foetuses (three per cent) were recorded following acetylsalicylic acid treatment, as compared to the control group (91 and nine per cent). Application of prostaglandin had no adverse effect on foetal development. The overall protein concentration in the amniotic fluid, following injection of progesterone/oestrone and PGF2 alpha, was lower with significance than the control value. Acetylsalicylic acid caused slight but insignificant rise in protein concentrations. The behavior of glucose concentrations in the amniotic fluid seemed to be diametrically opposed to that of protein. The activity of acid phosphatase was low and highly variable in all four experimental groups. Values moderately increased over the controls were recorded from the acetylsalicylic acid group.
Low pregnancy rate (62.5 per cent), low implantation results (64.7 per cent), high percentage of dead foetuses (5.4 per cent), and low allantois fluid volume/foetus (130.7 ml) are likely to suggest adverse effect of prostaglandin administered in early gravidity since all these values deviate sizeably from control data (81.3, 68.0 and 1.1 per cent, 154.7 ml). On the other hand, those negative phenomena were not reflected in the results obtained from biochemical analysis of amniotic fluid and foetuses. The progesterone/oestron and acetylsalicylic acid doses used obviously had no impact upon pregnancy rates (81.3 and 75.0 per cent) and overall implantates (67.4 and 69.6 per cent), when compared to the controls (81.3 and 68.0 per cent). The lowest foetal loss occurred following application of acetylsalicylic acid (30.4 per cent, but 32.0 per cent for the controls). Increase in allantois fluid volume/foetus by progesterone/oestrone and acetylsalicylic acid was one of the findings of particular interest (progesterone/oestron: 174.4 ml, acetylsalicylic acid: 196.5 ml, control: 154.7 ml). The results obtained from amniotic fluid tests (rises in protein and progesterone concentrations) may, to some extent, suggest the possible existence of a relationship in action between the two substances. No information at all on the type of action of these substances was obtainable by biochemical analysis of foetal composition.