Novel COL4A4 splice defect and in-frame deletion in a large consanguine family as a genetic link between benign familial haematuria and autosomal Alport syndrome.

BACKGROUND: Alport syndrome (AS) is a common hereditary cause for end-stage renal failure due to a defect in type IV collagen genes. The molecular pathogenesis of benign familial haematuria (BFH) is not fully understood. Evidence from linkage analyses and mutation studies point to a role of the COL4A3/COL4A4 genes. The present study describes molecular changes of the COL4A4 gene that cause both diseases: autosomal recessive AS and BFH in a consanguine family with a 400-year-old history of haematuria. METHODS: RNA and DNA were isolated and analysed by RT-PCR, PCR, DNA and cDNA sequencing, and Southern blotting. Evaluation of family members comprised creatinine clearence, urine analysis, audiometry and past medical history. RESULTS: Forefathers of this family moved to a German village in the 17th century. Sporadic episodes of macrohaematuria have been reported ever since. Numerous family members with haematuria including the parents of the index family were heterozygous for a splice defect eliminating exon 25 from the alpha4(IV) cDNA. The daughter (15 years old, creatinine clearence 27 ml/min, proteinuria 5 g/day, hearing loss) was homozygous for the mutation, while the son (22 years old, creatinine clearance 68 ml/min, proteinuria 11 g/day, hearing loss, splitted and thickened glomerular basement membrane) was heterozygous. Further analysis showed a second mutation, an 18 bp in-frame deletion in exon 25, for which numerous family members were heterozygous, and both children were homozygous. CONCLUSIONS: The COL4A4 splice defect causes BFH-phenotype in heterozygous, and AS in homozygous state. The clinical spectrum of heterozygous individuals reaches from macrohaematuria, intermittent microhaematuria to isolated deafness. The 18 bp in-frame deletion aggravates the phenotype in the compound heterozygous son. These results give further evidence that BFH and autosomal AS are in fact both type IV collagen diseases.     

Toxicodynamics of tumour promoters of mouse skin III. Specific binding of the tumour promoter thapsigargin as measured by the cold-acetone filter assay

Summary A method is described for measuring rapid, specific, and saturable binding of the skin irritant and tumour-promoting secretagogue thapsigargin (sesquiterpene lactone) to the microsomal fraction from mouse brain. Employing the tritium-labelled compound its apparent dissociation constant,K _d, and the maximal amount of bindingB _max are shown to be 9.8 nM and 1.9 pmol/mg protein respectively. Such aK _d for thapsigargin is similar to (a) its IC₅₀ value for inhibiting Ca²⁺ uptake in the microsomal fraction from rat brain and (b) its EC₅₀ values for inducing a rise in the cytoplasmic Ca²⁺ concentration of human platelets and histamine release from rat peritoneal mast cells. A positive correlation is found between the binding affinities of thapsigargin, thapsitranstagin, and trilobolide, their potencies as secretagogues and their lipophilicities. This correlation does not extend to the skin-irritant activities of the compounds thus emphasizing that their mechanism of action is unlike that of 12-O-tetradecanoylphorbol 13-acetate.Abbreviations Tg thapsigargin - Tt thapsitranstagin - Tr trilobolide - TPA 12-O-tetradecanoylphorbol 13-acetate - K _i,K _d apparent inhibition and dissociation constants - ID ₅₀ ⁵ irritant dose for 50% response after 5 h For II see Hergenhahn et al. 1991     

Holmium and thulium lasers: Comparison of solid state systems with potential applications for laser angioplasty

Three different Mid-infra-red laser systems with potential applications in peripheral and coronary angioplasty have been investigated: Free running Ho-Tm-Cr-YAG, Q-switched Ho-Tm-Cr-YAG and free running Tm-Cr-YAG. In vitro ablation experiments were performed with atherosclerotic plaque, using both single quartz fibres and multifibre ring catheters. Despite high ablation rates, the free running Ho-Tm-Cr-YAG laser caused thermal and acoustic damage to the tissue with carbonization effects, charring of the crater edges and severe vacuole formation. Using Q-switched Ho-Tm-Cr-YAG irradiation, thermal and acoustic side-effects were reduced, but the energy available from the system was too low to reach the ablation threshold with ring catheters. A free running Tm-Cr-YAG laser also showed limited tissue damage but its output energy was in excess of 1 J, allowing, therefore, effective catheter ablation.     

Validation of the BIOPAC indirect calorimeter for determining resting energy expenditure in healthy free-living older people

The BIOPAC indirect calorimeter for measuring resting energy expenditure (REE) is less cumbersome than many other calorimeters. We tested the hypothesis that the BIOPAC calorimeter is as well suited for determining REE in older people as traditional calorimeters. In 50 healthy persons (24 men and 26 women; age range, 61-83 years), REE by BIOPAC was validated against Vmax Spectra indirect calorimeter as a criterion method. Resting energy expenditure by BIOPAC was recorded at 2 different time intervals to find optimal conditions for older persons. Also, REE by 7 published equations was validated. The Bland-Altman procedure was used to test agreement between methods. Multiple regression analysis was applied to develop a new equation for predicting REE from BIOPAC. The BIOPAC calorimeter and most empirical equations significantly overpredicted mean REE in both sexes. Mifflin's equation best-predicted mean REE. Limits of agreement were wide for BIOPAC and narrow for most empirical equations. The Lührmann and Müller equations had smallest limits of agreement in men (±950 kJ/24 h) and the Harris-Benedict and Müller equations in women (±672 kJ/24 h). A new equation was developed for the BIOPAC device improving both predictions of mean and individual REE (R² = 0.671, standard error of the estimate = 136 kJ/24 h). Using this equation, 72.9% of subjects were lying within 10% of measured REE, compared with only 12.5% when using the manufacturer's algorithm. In conclusion, the BIOPAC calorimeter is suitable for measuring REE in healthy older adults when the new prediction equation is applied. This calorimeter is not applicable to frail older persons.     

Effects of low, subinhibitory concentrations of antibiotics on expression of a virulence gene cluster of pathogenic Escherichia coli by using a wild-type gene fusion

S fimbrial adhesins (Sfa) represent virulence factors of E. coli wild-type strains causing urinary tract infections and meningitis of the new born. In order to determine the influence of subinhibitory concentration of antibiotics on the expression of the sfa gene cluster, a wild-type strain carrying the lacZ gene, coding for the enzyme β-galactosidase fused to the sfa determinant was used. The expression of lacZ which was under the control of the sfa wild-type promoters, was now equivalent to the sfa gene expression of wild-type strain 536. With this strain the influence of subinhibitory concentrations of 28 antibiotics on the expression of the sfa determinant was studied. The expression was strongly suppressed by a treatment of the wild-type fusion strain by aztreonam, gentamicin, clindamycin and trimethoprim; the latter had a dramatic effect on sfa expression. It was further shown for clindamycin and trimethoprim that the reduction of sfa gene expression was dependent on the concentration of the antibiotics. In contrast imipinem, amphotericin B and rifampicin weakly stimulated sfa expression. We conclude that gene fusions between virulence-associated loci and indicator genes in wild-type pathogens are useful to study virulence modulation due to subinhibitory concentration of antibiotics on the genetic level.     

Polymers with carbazolyl groups, 3 Fluorescence properties of some polysiloxanes with pendant carbazolyl groups

The polarized fluorescence spectra and the time-resolved fluorescence decay of some novel carbazole-containing polysiloxanes were measured in solution and in the solid state. The fluorescence data show that these polymers, due to the conformational freedom of the carbazole group, are free of excimer-forming sites. As indicated by the extensive fluorescence depolarization in solid solution, the migration of excitation energy along the chain is fast with respect to the fluorescence lifetime, and the number of migrational steps comes up to the number of chromophores per chain. If the polymers were prepared starting from commercial carbazole (which contained small amounts of aromatic impurities), the occurrence of sensibilized benzocarbazole-like fluorescence in the solid state and in concentrated solution demonstrates the high efficiency of transferring the excitation energy to a suitable acceptor.     

Die Gesundheitsreform 2004 im vorparlamentarischen Beratungsverfahren zwischen Bund und Ländern*

Ohne Zusammenfassung*) Vortrag vor der Deutschen Gesellschaft für Kassenarztrecht e. V. in Berlin am 13. 11. 2003.     

Relations between axon length and axon caliber: Is maximum conduction velocity the factor controlling the evolution of nerve structure?

A search was made for any existent relationship between the length of a nerve fiber and the caliber of its axon. This was done in the hope of defining morphological parameters useful for assessing conduction time.Four fiber populations were examined: (1) phrenic fibers in rat and rabbit during different phases of body growth; (2) phrenic fibers of mature animals of greatly different body size including mouse and cow; (3) rat intercostal nerves which vary in length by a factor exceeding 5 due to the funnel-shape of the thorax; and (4) ventral root fibers of the cow.In all of these fiber populations, there was no evidence for a direct relationship between the length of a fiber and its caliber. Rather, a tendency was noted for fiber caliber to approach certain ceilings independent of length.These data, seen in conjunction with other information on fiber structure, cast serious doubt on the widely accepted concept that maximum conduction velocity is the factor controlling nerve structure. A much more likely factor controlling the structure of myelinated nerve fibers is the capacity to modulate information by frequency coding of impulses.     

Microbiological investigations on cryopreserved human semen

Primary mycological contamination was studied in 565 random human ejaculates. After sperm preservation at low temperature, secondary mycological contamination of 55 of the ejaculates was investigated. 25 ejaculates were cryopreserved with and without antibiotics and examined bacteriologically before and after different phases of cryopreservation. Furthermore, semen samples of several donors were inoculated with suspensions of different concentrations of yeasts and with the test bacteria Escherichia coli K 12 and Staphylococcus aureus SG 511. Microbiological results were then compared before and after cryopreservation. The following results were obtained: 1.9.8% of samples showed primary mycological contamination (1.9% with Candida albicans). 2. Cryopreservation reduced the concentration of fungi by more than 90% on average. 3. Only one semen sample was contaminated with bacteria (Staphylococcus aureus haemolyticus and Streptococcus nonhaemolyticus). Non-pathogenic bacteria were found in 11 ejaculates (Micrococcus luteus in 5 samples and Staphylococcus epidermidis in 6 samples), and contamination was largely unaffected by cryopreservation, even in the presence of antibiotics. 4. Test bacteria inoculated into semen were not influenced by the addition of antibiotics to the cryoprotective medium.     

Urge incontinence in the elderly – supraspinal reflex incontinence

World Journal of Urology -