Differential effects of aldosterone and ADH on intracellular electrolytes in the toad urinary bladder epithelium

Summary Quantitative electron microprobe analysis was employed to compare the effects of aldosterone and ADH on the intracellular electrolyte concentrations in the toad urinary bladder epithelium. The measurements were performed on thin freeze-dried cryosections utilizing energy dispersive x-ray microanalysis. After aldosterone, a statistically significant increase in the intracellular Na concentration was detectable in 8 out of 9 experiments. The mean Na concentration of granular cells increased from 8.9±1.3 to 13.2±2.2 mmol/kg wet wt. A significantly larger Na increase was observed after an equivalent stimulation of transepithelial Na transport by ADH. On average, the Na concentration in granular cells increased from 12.0±2.3 to 31.4±9.3 mmol/kg wet wt (5 experiments). We conclude from these results that aldosterone, in addition to its stimulatory effect on the apical Na influx, also exerts a stimulatory effect on the Na pump. Based on a significant reduction in the Cl concentration of granular cells, we discuss the possibility that the stimulation of the pump is mediated by an aldosterone-induced alkalinization.Similar though less pronounced concentration changes were observed in basal cells, suggesting that this cell type also participates in transepithelial Na transport. Measurements in mitochondria-rich cells provided no consistent results.     

Investigations on the population genetics of the α1-antitrypsin polymorphism

Summary The results of Pi-typing on 2647 individuals from 9 populations are reported. Of the 17 phenotypes and 9 alleles described in literature, we found 12 phenotypes and 8 alleles. The population smaples differ characteristically in their allele frequencies. The allle Pi^M appears constantly in all populations tested with a frequency of more than 0.85. The alleles Pi^F (0.01–0.11), Pi^S (0.01–0.02) and Pi^Z (0.01–0.02) were also relatively frequent in all samples. All the other alleles remain below 0.01. A great increase in the number of Pi-variants was observed in the Central European area. The frequency of ₁-at variants in various populations is discussed.Supported by the Deutsche Forschungsgemeinschaft.Dedicated to Prof. W. Lehmann, Kiel, on his 65th birthday.     

Estimation of the mean floristic similarity between and within sets of vegetational relevés

Various possibilities of usingSörensen's coefficient of floristic similarity in plant sociology are summarized. A new formula (11), derived from that bySörensen and based on constancy values, is suggested in order to calculate the mean floristic similarity within a set of relevés.     

Estimation of the mean floristic similarity between and within sets of vegetational relevés

Various possibilities of usingSörensen’s coefficient of floristic similarity in plant sociology are summarized. A new formula (11). derived from that bySörensen and based on constancy values, is suggested in order to calculate the mean floristic similarity within a set of relevés.     

Neue Ergebnisse über die Arbeitshyperthermie des Menschen

Nielsen (1938) demonstrated that hypothermia during exercise is independent of room temperature within a range from 5° to 32° C. Subsequently, other investigators confirmed this observation. From these results,Asmussen &Nielsen (1947) concluded that a resetting of the thermoregulatory centre brought about by impulses reaching the brain from the working muscles or from the motor centres takes place. In order to find out whether impulses from motor centres really affect the thermoregulatory centres, we tried, by administration of curare in human beings, to increase the frequency of impulses necessary to bring about a certain amount of mechanical work. However, in 2 series of experiments at room temperatures of 23° and 34° C respectively and at a constant work output of 3 mkp/sec, no significant differences in body temperature (measured in the lower esophagus) before and during curare infusion could be detected. In the resting conditions, curare exerts no influence on body temperature. In normal subjects performing low work (3 mkp/sec) the body temperature decreases at a room temperature of 23° C but increases at a room temperature of 32° C. In conclusion, the hyperthermia during exercise cannot be due to a resetting of thermoregulatory centres. It works rather like a proportional closed loop control system. The relative independence of the hyperthermia from the environmental temperature suggests a considerable influence of the latter parameter via the thermoreceptors of the skin on the thermoregulation during work.     

Expression of CD44 Splice Variants During Lymphocyte Activation and Tumor Progression

Recently, splice variants of CD44 have been described that confer metastatic potential to non-metastasizing rat pancreatic carcinoma and sarcoma cell lines. Using antibodies against variant CD44 (CD44v) sequences, we have examined the expression of variant CD44 glycoproteins on human lymphoid cells and tissues and in colorectal neoplasia. Lymphohematopoietic cells express low levels of CD44v glycoproteins. During the process of lymphocyte activation in vitro and in vivo, expression of CD44v glycoproteins is transiently upregulated. The reaction pattern of various antibodies indicates that these CD44 variants contain the domain encoded by exon v6, which is part of the variant that confers metastatic capability. In human colorectal neoplasia we observed overexpression of CD44 splice variants in all invasive carcinomas. Already at early stages of colorectal tumor progression exon v5 epitopes were overexpressed. Tumor progression was strongly related to expression of CD44 isoforms containing exon v6 encoded domains. The findings establish CD44 variants as tumor progression markers in colorectal cancer.     

Characterization of a 100-kilodalton binding protein for the six serotypes of coxsackie B viruses.

Viral infection of host cells primarily depends on binding of the virus to a specific cell surface protein. In order to characterize the binding protein for group B coxsackieviruses (CVB), detergent-solubilized membrane proteins of different cell lines were tested in virus overlay protein-binding assays. A prominent virus-binding protein with a molecular mass of 100 kDa was detected in various CVB-permissive human and monkey cell lines but was not detected in nonpermissive cell lines. The specificity of CVB binding to the 100-kDa protein on permissive human cells was substantiated by binding of all six serotypes of CVB and by competition experiments. In contrast, poliovirus and Sendai virus did not bind to the 100-kDa CVB-specific protein. A fraction of HeLa membrane proteins enriched in the range of 100 kDa showed functional activity by transforming infectious CVB (160S) into A-particles (135S). In order to purify this CVB-binding protein, solubilized membrane proteins from HeLa cells were separated by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by elution of the 100-kDa protein. Amino acid sequence analysis of tryptic fragments of the CVB-binding protein indicated that this 100-kDa CVB-specific protein is a cell surface protein related to nucleolin. These results were confirmed by immunoprecipitations of the CVB-binding protein with nucleolin-specific antibodies, suggesting that a nucleolin-related membrane protein acts as a specific binding protein for the six serotypes of CVB.     

Alchemilla austriaca,spec. nova,(Rosaceae) — eine neue Art aus den Ostalpen

Alchemilla austriaca is a new species which belongs to the group ofA. demissa, A. frigens, A. longana, A. longiuscula, A. semisecta, andA. sinuata. The holotype specimen as well as leaf and flower details are illustrated (Figs. 1–3). A complete character analysis is given, differences and similarities of allied species are presented in two tables, and the position of the group within the genus is discussed.A. austriaca so far is known only from the Austrian Alps and mainly from the central ranges (distribution map: Fig. 4). Its wet subalpine and alpine habitats are characterized by species lists.

     

Der Einfluss von CCC auf die Entwicklung des Roggenhalmes

Field trials on the effect of chlorocholinechloride (CCC) on rye plants of the cultivar Danae and of a selected population “WRS” proved that rye principally shows as reaction analogous to wheat. The CCC-induced decrease of stalk length is due to the reduction of elongation growth of the 4th internode. This shortening effect is mainly the result of decreased cell extension and, in the middle internode, additionally of inhibited cell division in longitudinal direction. The shape of internodes is changed under the influence of CCC. Walls of parenchyma cells of CCC-treated plants are thinner and those of sclerenchyma cells are thicker compared with cell walls of control plants.