Diagnosis and metaphylaxis of stone disease. Consensus concept of the National Working Committee on Stone Disease for the upcoming German Urolithiasis Guideline

This review draws the recent state of the art in metabolic diagnosis and metaphylaxis of stone disease. It is the basis for the consensus approval with the other medical societies and institutions in Germany involved in the guideline process of the new "Urolithiasis Guideline". The German Working Committee on Stone Disease reviewed critically the current literature in the field of urolithiasis-including the existing German and EAU-Guidelines as well as the Conference Book of the First International Consultation on Stone Disease. As far as possible the references were rated according to the EBM criteria. On this basis the expert group discussed all pathways and statements regarding the management of stone disease. The present review coincides with the consented guideline draft of the German Working Committee on Stone Disease. Occurrence of stone disease in the western world increases seriously. Modern lifestyle, dietary habits and overweight-problems of the affluent societies-emerge to be the important promoters of the "stone-boom" in the new millennium. This even affects children, whose stone prevalence is otherwise significantly less than that of adults. Criteria for the high risk group of stone formers were clearly defined. A diagnostic standard is formulated for the basic and the elaborate metabolic evaluation of a stone patient. Approximately 75% of all stone patients could anticipate stone recurrence with elementary reorientation of their lifestyle and dietary habits, summarized as general metaphylaxis. About 25% of the stone formers require additional pharmacological intervention to normalize their individual biochemical risk, precisely compiled for each stone type as specific metaphylaxis.

Antibodies against protein Z and fetal loss: current perspectives

Protein Z (PZ) is a vitamin K-dependent plasma protein that serves as a cofactor for the inactivation of factor Xa. A number of investigators found low PZ levels in patients with haemorrhagic as well as thromboembolic diseases, although there is no clear evidence of a pathogenic link between PZ deficiency and these clinical disorders. Nevertheless, low PZ levels have been found in association with early fetal losses, especially those occurring before the 15th week of gestation and in patients with detectable antiphospholipid and anti-PZ antibodies. The current diagnostic relevance and therapeutic consequences of these parameters will be discussed.

Problems in the investigation of urine from patients suffering from primary hyperoxaluria type 1

Regular calculation of urinary crystallization risk indices in patients suffering from urolithiasis is a recommended measure for treatment adjustment. The more the patient experiences either extensive stone formation or an enhanced recurrence rate, the more important risk index calculations. In patients suffering from primary hyperoxaluria type 1 (PH1), both criteria are met. Different methods of risk determination are known. All strategies for measuring the calcium oxalate (CaOx) crystallization risk of a given urine principally determine this parameter from voided urine. This "bladder urine", however, has possibly passed stone material located in the urinary tract and thus may be depleted in lithogenic components. This is commonly the case for patients with PH1, who mostly experience a massive stone burden or severe nephrocalcinosis. Hence, the question arises as to whether we can adequately determine the crystallization risk in the urine of stone-bearing PH1-patients or not. Based on model calculations, we show that the determination of CaOx formation risk in PH1-patients requires knowledge of the restrictions in risk index interpretation: risk indices calculated from urinalysis (e.g. EQUIL) still indicate, even after strong in vivo stone formation, an enhanced but in fact strongly underestimated risk value. However, the outcome "enhanced" masks the patient's true risk situation. The BONN Risk Index (BRI), in contrast, discloses the process of extreme in vivo crystal formation. As determined, inter alia, from the urinary concentration of free ionized calcium ([Ca(2+)]), BRI approaches abnormally low values, as, in consequence of CaOx - formation, [Ca(2+)] tends to values close to zero. Thus, calculations of urinalysis-based risk indices alone are insufficient strategies for the quantification of a PH1 patient's CaOx crystallization risk.

Identification and characterization of a novel HLA-DRB1 allele, DRB1*0830*

Here, we report on the identification and characterization of a novel human leukocyte antigen (HLA) DRB1 allele, DRB1*0830. This allele was identified in a candidate for hematopoietic stem cell donation. While the DNA sequence of HLA-DRB1*0830 most closely matches to DRB1*080202, its amino acid sequence resembles DRB1*080202 and DRB1*0813. Due to a substitution at nucleotide position 286 HLA-typing using sequence-specific oligonucleotide hybridization or amplification using sequence-specific primers gave inconclusive results. Allele-specific DNA sequencing confirmed a 286 T-->A substitution resulting in Phe67Ile.

B*4440: a novel HLA-B allele identified by sequence-specific oligonucleotide hybridization and sequence-specific amplification

A novel human leukocyte antigen B (HLA-B) allele, B*4440, is described. The allele was identified in an adult stem cell donor of Caucasian origin. HLA-B*4440 most closely matches to B*4403 differing by a substitution of three nucleotides at codon 44, 45, and 50. Thus, low-resolution HLA typing using sequence-specific oligonucleotide hybridization or amplification using sequence-specific primers gave inconclusive results. DNA sequencing confirmed a variation of codons 44 and 45 (AGG AAG-->AGA GAG) and codon 50 (CCA-->CCG), resulting in an amino acid substitution Lys-->Glu at codon 45.

Description of a novel HLA-B allele, B*5613, identified during HLA-typing using sequence-specific oligonucleotide hybridization and sequence-specific amplification

Here, we report on the characterization of a novel human leukocyte antigen (HLA)-B allele, B*5613. The allele was identified in an adult male from North Africa who was suffering from sickle cell anemia. HLA-B*5613 most closely matches to B*5601 differing only by a substitution of three nucleotides of codon 180. Due to this substitution, low-resolution HLA-typing using sequence-specific oligonucleotide hybridization or amplification using sequence-specific primers gave inconclusive results. DNA sequencing confirmed a variation of codon 180 (CTG-->GAC) resulting in an amino acid substitution Leu156Asp.

Prevention Against Oxidative Stress of Eukaryotic Cell Membranes by Selenium Compounds of the Rat

By a combination of trace techniques and various biochemical methods, information about the characteristics of a 15-kDa selenoprotein was obtained. After labeling of rats in vivo with [(75)Se]selenite, subcellular fractionation of the homogenates of the prostate, lung, brain, thyroid gland, and large intestine, and gel electrophoretic separation of the proteins and subcellular fractionation, 15-kDa (75)Se was found in the cytosols of the tissues prostate > brain > lung > thyroid gland > large intestine after autoradiography. After coelectrophoresis of the separated 15-kDa labeled band obtained from each cytosolic fraction, the 15-kDa (75)Se band migrated in the same way as the combined bands isolated from the five tissue cytosols. After proteolytic cleavage in the gel of the 15-kDa labeled band obtained from the cytosol of each tissue and re-electrophoresis, the same labeled peptide pattern was found in each gel slice after autoradiography. By means of reversed-phase HPLC, we characterized a selenocysteine-containing protein that has enzymatic activity like that of glutathione peroxidase.

Grip force parameters in precision grip of individuals with myelomeningocele

The aim of this study was to characterize impairments of hand function in individuals with myelomeningocele (MMC) using a quantitative method. A grip-lift task was studied in 29 individuals with MMC (17 females, 12 males; mean age 12 years 4 months, SD 5 years 6 months; range 4 to 28 years) and 29 age- and sex-matched control participants. A small object (weight 200 g) was grasped and lifted with a precision grip of the dominant hand and grip forces (GF) and time intervals were measured. Sensibility was examined with a two-point discrimination test. In those with MMC, the latency between GF onset of the thumb and index finger and ensuing preload duration were both significantly prolonged (p<0.01). Fingertip forces were excessively high and variable. Several parameters differed significantly between those with MMC and control individuals: GF peak, GF at start of loading, mean GF, and the SDs of the GF during static holding. Although the two-point discrimination task indicated deficits of sensibility, these did not correlate with grip force parameters. Results demonstrate that fine motor skills in patients with MMC are impeded by slowness and inadequate adjustments of manipulative forces.

Detection and characterization of membrane-bound selenoproteins in the kidney of the rat

The essential trace element selenium is of fundamental importance to human biology. Information on the membrane-bound selenoproteins was obtained by labeling of rats in vivo with (75)Se-selenite, subcellular fractionation of the tissue homogenates, separation of the proteins by SDS-PAGE, two-dimensional electrophoresis, and selenium detection by autoradiography. In this way, in addition to already known membrane-bound selenoproteins three novel selenoproteins in the molecular mass range of 38-40, 18, and 12-13 kDa were detected in the microsomal membranes.

Type I IgE receptor, interleukin 4 receptor and interleukin 13 polymorphisms in children with nephrotic syndrome

Polymorphisms in the genes encoding the high-affinity IgE receptor, the interleukin 4 (IL4) receptor and IL13 can be associated with the development of asthma and allergy. Although several studies have described an association between atopy and idiopathic childhood nephrotic syndrome (NS), it is not clear whether this association is of a causal nature. Furthermore, it is not known whether these polymorphisms are associated with the clinical course of NS. A total of 84 children (52 male and 32 female; mean age 12.1 years) with NS were included in the present study. Of these, 78 could be classified as either atopic or non-atopic. Atopy was defined by elevated IgE levels (>100 k-units/l) and/or a positive history of atopy (33 of 78 patients). DNA was extracted from blood collected in EDTA tubes, and polymorphisms at positions 50 and 551 of the IL4 receptor, position 110 of IL13 and position 181 of the high-affinity IgE receptor were investigated by sequence-specific PCR or direct sequencing. Although we noted a strong tendency towards a higher allele frequency of polymorphisms in children with atopy and NS compared with children with NS but without atopy (IL4 50, 30% compared with 18%; IL4 551, 39% compared with 31%; IL13 110, 45% compared with 33%; IgE 181, 12% compared with 13%), these differences did not reach statistical significance. There were no differences in the frequency of polymorphisms between the different clinical courses of NS (frequent relapsers, steroid-dependent or steroid-resistant NS). We conclude that polymorphisms in the IL4 receptor, the high-affinity IgE receptor and IL13 do not seem to predict the clinical course of NS, despite the fact that serum IgE elevations are more frequent in patients with NS than in normal control subjects. The investigated polymorphisms may contribute to the IgE switch in patients with NS.

Acute haemolytic transfusion reactions due to weak antibodies that in vitro did not seem to be clinically significant

BACKGROUND AND OBJECTIVES

In the present article, we report on two patients with acute haemolytic transfusion reactions (AHTRs), and whom we were unable to transfuse, owing to alloantibodies that in vitro did not seem to be clinically significant.

MATERIALS AND METHODS

The patients were a 67-year-old male and a 64-year-old female, both of whom developed antibodies to red blood cells (RBCs) after repeat blood transfusions. Serological analyses were carried out using standard techniques.

RESULTS

Both patients developed an AHTR of the intravascular type following blood transfusions. Serological re-examination revealed weakly reactive alloantibodies with anti-JMH specificity in one patient, and with unclear specificity in the second. Rechallenging the patients with 15-30 ml of packed RBCs caused AHTRs, and blood transfusion became impossible in both cases.

CONCLUSION

Weak alloantibodies that in vitro do not seem to be clinically significant may cause severe AHTRs.

Light microscopical investigations on structural changes of skeletal muscle as artifacts after postmortem stimulation

Samples of skeletal muscle were taken from 20 human corpses where mechanical or electrical stimulation had been carried out up to 8h postmortem (hpm) in order to estimate the time since death. The stimulation had caused an idiomuscular bulge or tetanic contraction of the muscle tissue at this location. The muscle samples were examined for structural changes of the fibers by light microscopy. A comparison with control muscle samples taken contralaterally from the same corpse, showed that the findings previously interpreted as being of intravital origin, e.g. destruction of fiber integrity, invagination and contraction bands, could also be due to postmortem alterations. It is hypothesized that structural changes to the muscle fibers can, in general, be produced as long as the manifestation time is shorter than the supravital phase after the time of force impact.

Increased RBC autoantibody production in pregnancy

BACKGROUND

Autoimmunization against RBCs is generally believed to occur very rarely during pregnancy and to represent a high risk for those affected. The occurrence of benign RBC autoantibodies in pregnancy is reported.

STUDY DESIGN AND METHODS

The incidence of autoantibodies to RBCs in unselected pregnant and nonpregnant women were compared by the new standard gel hemagglutination method.

RESULTS

Data from a total of 22,782 pregnant and 12,903 nonpregnant women were analyzed. The antibody screen test was positive in 547 (2.40%) of the pregnant women. The positive test results were related to passive anti-D in 341 cases (1.50%), to clinically relevant alloantibodies in 43 cases (0.19%), to clinically irrelevant antibodies in 138 cases (0.61%), to autoantibodies in 23 cases (0.1%), and to autoantibodies plus alloantibodies in 2 cases (0.01%). In the cases of alloantibodies and/or autoantibodies, the DAT was invariably positive with anti-C3d and less commonly so with anti-IgG. The autoantibodies were first detected during pregnancy, they predominantly reacted with enzyme-treated RBCs, and none of the affected women or their infants appear to have developed clinically significant hemolysis. In the control group consisting of nonpregnant female blood donors, there were 3 cases (0.02%) of clinically insignificant IgG autoantibodies.

CONCLUSION

There is an increase in autoimmunization against RBCs during pregnancy. The resultant autoantibodies do not appear to cause significant RBC destruction. Further studies are required for precise characterization of this phenomenon.