Polymere imidazolcarbonsäuren, 2. Über das schwermetallionenbindungsvermögen von chelatharzen mit 4,5-sicarboxyimidazolyl-gruppen

The swelling behaviour, the time-dependence of the uptake of Cu²⁺-ions, and the pH-dependence of the uptake of Cu²⁺-, Ni²⁺-, Cd²⁺-, Zn²⁺- and Mg²⁺-ions of crosslinked poly[1-(4,5-dicarboxy-1-imidiazolyl)ethylene] ( 1 ) and poly{1-[p-(4,5-dicarboxy-2-imidazolyl)phenyl]ethylene} ( 2 ) were investigated. Both resins have a high selectivity for heavy metal ions. For resins 1 the uptake of heavy metal ions in the presence of an excess of EDTA was studied. Furthermore the possibility to remove Hg²⁺-ions from aqueous alkalichloride solutions by resin 1 was investigated.     

Serum creatinine concentration and renal interstitial volume

Summary Renal biopsies of 44 patients with endocapillary acute glomerulonephritis (gn) and 64 patients with moderately severe mesangioproliferative gn were investigated morphometrically (point-counting-method, tubulometry).In both gn's statistically significant positive correlations between relative interstitial volume and the concentration of serum creatinine at the time of biopsy were found.Despite severe glomerular lesions the serum creatinine concentration is not increased in most cases of endocapillary acute gn, providing the relative interstitial volume is not increased by more than 15%.Increased serum creatinine concentration without a markedly enlarged interstitium was found in 11 cases of endocapillary acute gn with clinically and morphologically proven acute renal failure. In these cases the glomerular function is probably impaired by the Thurau-mechanism.In all other patients, especially in those with moderately severe mesangioproliferative gn, the serum creatinine concentration rises with an enlargement of relative interstitial volume. This reduction of renal function may be explained by a decrease to the total cross-sectional area of postglomerular vessels, caused by interstitial fibrosis. That may possibly lead to diminished renal blood flow and glomerular filtration with an increase of the serum creatinine concentration.Supported by the Deutsche Forschungsgemeinschaft     

Tolerance and immunity to the inducible self antigen C-reactive protein in transgenic mice

The understanding of immunological tolerance has been greatly aided by the development of transgenic animal models in which expression of a specific T cell receptor (or B cell receptor) and its cognate self antigen is experimentally controlled. In most cases, expression of the self antigen was constitutive and did not allow for variation of its time- and dose-dependent expression pattern, parameters which are known to influence the balance of tolerance versus immunity. We describe a transgenic model in which expression of human C-reactive protein (hCRP), an acute-phase protein, is tightly controlled at basal levels (female mice express around 10^?9 M and male mice 5 × 10^?7 M circulating hCRP) and is highly inducible (induction factor of 25–500). T cells from C57BL/6 mice recognize two epitopes of hCRP termed A (residues 79–95) and B (residues 87–102). Different efficacies of presentation in vitro and in vivo identify epitope A as subdominant and epitope B as dominant. T cells of non-induced hCRP transgenic mice are tolerant to the dominant epitope, but reactive to the subdominant epitope. A hCRP-specific IgG antibody response is detectable in transgenic mice, but is weaker than in littermates. Upon induction of hCRP, both T cell epitopes are presented by thymic and splenic antigen-presenting cells (APC) in vivo. Kinetics of presentation by splenic APC closely match serum kinetics of hCRP, whereas presentation in the thymus is considerably prolonged. This model enables epitope-specific T cell tolerance to be studied as a function of time- and dose-dependent expression of the self antigen.     

Modifizierung von homo- und copolymeren des epichlorhydrins durch polymeranaloge umsetzungen

Poly(epichlorohydrin) and poly(epichlorohydrin-co-ethylene oxide) were modified by reaction with potassium thiocyanate (KSCN), tetrabutylammonium p-toluenesulfinate (NBu₄SO₂C₇H₇) and tetrabutylammonium benzenesulfinate (NBu₄SO₂C₆H₅). Though the substitution of chlorine in the polymers with these nucleophilic reagents in most cases is accompanied by side reactions, appropriate reaction conditions allow degrees of substitution higher than 90% to be obtained. The glass transition temperature (T_g) of the thiocyanate-modified homo- and copolymer exhibits only a small increase with increasing degree of substitution. While the T_g of the original homo- and copolymer is observed at ?20°C and ?38°C, respectively, the glass transition of the highly substituted homopolymer occurs at ?12°C and for the copolymer at ?31°C. On the other hand, the thiocyanate-modified polymers show a remarkably higher decomposition temperature of about 250°C as compared with that of the unmodified polymers (160–180°C). In addition, the solubility is markedly influenced by the substitution. While the original homo- and copolymers are soluble in, e.g., benzene and toluene, the highly modified products are only soluble in polar solvents such as THF, acetone, DMSO and diglyme. Introducing sulfonyl groups, the resulting polymers exhibit a glass transition temperature increased to a greater extent. For the homopolymer with the highest degree of substitution (98,3%), a T_g of 73°C is observed. Concerning the decomposition temperature, a drastical increase up to 370°C occurs. Finally the influence of phase transfer catalysts on the described reactions was investigated.     

Microproteins in amniotic fluid as an index of changes in fetal renal function during development

Protein content and protein composition were studied in amniotic fluid obtained from 171 healthy pregnant women between the 16th and 38th week of gestation, using microgradient gel electrophoresis to separate proteins according to their molecular size into albumin (68 KD), proteins of low molecular weight (LMW proteins, <68 KD), and proteins of high molecular weight (HMW proteins, >68 KD). Additionally -1-microglobulin (-1-MG, 33 KD) and -2-microglobulin (-2-MG, 11,8 KD) were analysed as micromolecular marker proteins. Concentrations of LMW proteins were 0.15–0.22 g/l, of -1-MG 28.4–34.5 mg/l, and of -2-MG 7.2–11.6 mg/l during the second trimester of gestation, and thereafter decreased progressively to 0.03 g/l, 14.1 mg/l and 2.4 mg/l respectively near term. The same developmental trends were confirmed by calculating the protein/creatinine ratios in amniotic fluid. The concentrations of LMW proteins found in the first postnatal urine of 73 healthy infants born prematurely or at term were similar to those in amniotic fluid of corresponding fetal age. Concentrations of albumin and HMW proteins in postnatal urine were about 5% and 15% respectively when compared with amniotic fluid concentrations. No strong correlation existed between gestational age and either of the analysed proteins which would allow accurate assessment of fetal maturation by protein analysis in amniotic fluid. It is concluded that fetal urinary excretion is the major determinant of the microprotein content of amniotic fluid. Microproteins seem to reflect an increasing tubular reabsorption capacity, which accelerates rapidly after the second trimester of gestation.     

Cystometric changes in the early phase of streptozotocin-induced diabetes in rats: evidence for sensory changes not correlated to diabetic neuropathy

Summary 1. The effect of streptozotocin (STZ) induced diabetes on rat urinary bladder function was investigated by means of in vivo cystometry and in vitro recording of bladder strips contractility. A group of sucrose-fed animals was included to determine to what extent the STZ-induced changes were ascribable to the increased diuresis. 2. After 7–9 weeks from STZ injection there was a marked increase in weight of bladder and ureters. Cystometry revealed a marked increase in bladder capacity (volume threshold) although pressure threshold and amplitude of micturition contraction were unaffected. Sucrose-fed animals, having normal blood glucose levels but a similar increase in urine production exhibited cystometric changes identical to those of STZ animals. 3. In vitro experiments indicated that the response to field stimulation (0.1–20 Hz) is reduced in STZ-pretreated but increased in sucrose-fed animals, as compared to controls. 4. The content of urinary bladder and ureters in sensory neuropeptides (substance-P, neurokinin-A and calcitonin-gene related peptide-like immunoreactivity) was increased by STZ diabetes when values were corrected for the increased weight of these organs. 5. The capsaicin-induced contraction of the rat isolated bladder strips, presumably caused by neuropeptides released from intramural sensory nerves, is unaffected by STZ diabetes. 6. These findings indicate that STZ diabetes produces, at an early stage, changes similar to those reported to occur in the human disease, e. g. a greater bladder capacity with unimpaired voiding function. The increased bladder capacity of STZ-rats seems largely, if not solely, ascribable to changes in physical properties of the detrusor muscle, thereby allowing accomodation of greater than normal volumes with similar increase of intraluminal pressure. No sign of diabetic neuropathy of the capsaicin-sensitive sensory nerves can be observed at this stage (7–9 weeks) of STZ diabetes. Send offprint requests to P. Santicioli at the above address     

Impact of postanesthesia care unit delirium on self-reported cognitive function and perceived health status: a prospective observational cohort study

Quality of Life Research - The objective of this study was to determine the influence of postanesthesia care unit (PACU)&nbsp;delirium on self-reported cognitive function and perceived health...     

Tula Virus as Causative Agent of Hantavirus Disease in Immunocompetent Person,Germany

We report molecular evidence of Tula virus infection in an immunocompetent patient from Germany who had typical signs of hantavirus disease. Accumulating evidence indicates that Tula virus infection, although often considered nonpathogenic, represents a threat to human health.