Extrarenale Elektrolyt- und Wasserverteilung unter Thyroxin

Zusammenfassung Es wurde die extrarenale Elektrolytverteilung nach oraler Zufuhr von d,l-Thyroxin bestimmt.Thyroxin führt an Leber- und Muskelzellen zu einer Hemmung des aktiven Na-Transportes. Der aktive K-Transport wird nicht beeinflußt. Cl verhält sich wie Na.Die Verteilung des Wassers wird an der Muskulatur durch Thyroxin nicht geändert, in der Leber erfolgt eine Wasserverschiebung von der IZF nach der EZF.Die Wirkungen des Thyroxins und 2,4-Dinitrophenols auf die Elektrolyt-und Wasserverteilung werden miteinander verglichen.VI. Mitteilung.     

Steuerung des cellulären Elektrolyt- und Wassergehaltes durch Hormone

Zusammenfassung Wir prüften an Ratten den Einfluß von Aldosteron, Progesteron, Testosteron, Oestradiol, Oxytocin, Vasopressin, Adrenalektomie, Nephrektomie, Ovarektomie, Hodenentfernung und Gravidität auf den cellulären Elektrolyt- und Wassergehalt in Leber und Muskel.Die Methode besteht darin, daß vom Gesamt-Elektrolyt- und-Wassergehalt der extracelluläre Anteil, den wir mit Hilfe der Serumkonzentration und des Rohrzuckerraumes in den Organen ermittelten, abgezogen wird.Es ergibt sich, daß Aldosteron und Testosteron den aktiven Na- und K-Transport durch die Leber- und Muskelzellmembranen aktivieren, Oxytocin und Vasopressin dagegen hemmen.Oestradiol wirkt nur auf den aktiven Na-Transport und in dieser Hinsicht, in der Leber dem Aldosteron, im Muskel dem Vasopressin synergistisch.Progesteron scheint ebenso wie die normale Gravidität nur Cl und Wasser in die Zellen eintreten zu lassen.Adrenalektomie, Ovarektomie und Hodenentfernung führen zu einer Hemmung des aktiven Na- und K-Transportes.Es werden die Beziehungen des Na- und K-Transportes zu Cl- und Wasserbewegungen diskutiert und die Elektrolyt- und Wasserbewegungen unter Hormoneinflüssen zwischen extracellulärer und intracellulärer Flüssigkeit mit denen zwischen extracellulärer Flüssigkeit und Harn verglichen.Ausgezeichnet mit dem Karl-Thomas-Preis 1960.     

Einfluß von 2,4-DNP auf die intra- und extracelluläre Elektrolytverteilung in vivo

Zusammenfassung Wir prüften in vivo den Einfluß von 2,4-DNP auf die Elektrolyt- und Wasserverteilung in Leber und Muskulatur von Ratten. In Serum nimmt die Na-Konzentration gegenüber Kontrolltieren ab und die K-Konzentration zu.Wir bestätigen in vivo, daß Entkopplung von Atmung und oxydativer Phosphorylierung durch 2,4-DNP zu einer Hemmung des aktiven Kationentransportes in den Leberzellen führt. Gleichzeitig mit der Hemmung des aktiven Kationentransportes fließen Cl und H₂O in die Zellen.In den Muskelzellen wird nur der aktive K-Transport gehemmt, der Na-Transport wird durch 2,4-DNP nicht beeinflußt. Gleichzeitig nimmt der Cl- und H₂O-Gehalt der Muskelzellen zu.V. Mitteilung. I.–III. Mitteilung ist erschienen in Clin. chim. Acta (1958). IV. Mitteilung ist erschienen in Naunyn-Schmiedeberg's Arch. exp. Path. Pharmak. 238, 368 (1960).     

Relationships between trehalose metabolism and maltose utilization in Saccharomyces cerevisiae

Summary A pattern of active accumulation of trehalose during growth on glucose medium, TAC(+) phenotype, is controlled by a polymeric series of maltose fermentation (MAL) genes. An essential requirement for expression of the TAC(+) phenotype is that the MAL gene be in the constitutive state, MAL ^c. Mutation of a constitutive MAL allele to a maltose- inducible or nonfermenting (mal) state, alters the pattern of trehalose metabolism so that little or no trehalose accumulation occurs during growth on glucose medium. The TAC(+) phenotype is obtained in MAL ^c strains whether or not -glucosidase formation is sensitive or resistant to carbon catabolite repression. However, trehalose accumulation is sensitive to glucose levels even in MAL ^c strains in which -glucosidase formation is insensitive to catabolite repression. The effects of constitutive MAL genes on trehalose accumulation cannot be accounted for by an increase in trehalose-6 phosphate synthase or a decrease in trehalase as determined in vitro. A mechanism is proposed in which the gene-product of a MAL gene serves as a common positive regulator for expression of four genes coding respectively for maltose permease, maltase, -methylglucosidase and a component of the trehalose accumulation system.Paper I appeared in Cell. and Molec. Biology 25: 345–354, 1979     

Antigen-specific therapies in multiple sclerosis: going beyond proteins and peptides

Multiple sclerosis (MS) is a complex immune-mediated disease resulting largely from an autoimmune attack against components of central nervous system myelin, including several proteins and lipids. Knowledge about the details of this anomalous immune response has come mostly from studies in the animal model experimental autoimmune encephalomyelitis (EAE). In this model, it has been possible to prevent and effectively treat established disease through several antigen-specific therapeutic strategies, which have included administration of whole myelin or myelin proteins by various routes, random copolymers consisting of the main major histocompatability complex (MHC) and T-cell receptor (TCR) contact amino acid residues, altered peptide ligands of dominant myelin epitopes in which one or more residues are selectively substituted, and lately DNA vaccination encoding self-myelin antigens. However, there have been difficulties in making successful transitions from animal models to human clinical trials, due either to lack of efficacy or unforeseen complications. Despite these problems, antigen-specific therapies have retained their attraction for clinicians and scientists alike, and hopefully the upcoming generation of agents--including altered peptide ligands and DNA vaccines--will benefit from the increasing knowledge about this disease and surmount existing difficulties to make an impact in the treatment of multiple sclerosis.     

Miliary brain metastases from primary gastric small cell carcinoma: illustrating the seed and soil hypothesis

Miliary metastases are a very rare condition usually found in the context of primary lung tumor (small cell and adenocarcinoma), and refer to the existence of numerous tumor nodules in widespread areas of the brain. Besides pulmonary neoplasia, pancreatic adenocarcinoma and malignant melanoma have also been implicated in some cases of miliary metastases. We present the first case of miliary metastases originating in a primary small cell gastric carcinoma (PSCGC), a rare type of neuroendocrine gastric tumor. This location should therefore be investigated whenever other more frequent tumors have been excluded as a cause for this particular type of metastases. The pathological resemblance of PSCGC with small cell lung carcinoma may correspond to an underlying similarity in biological behavior, which accounts for this particular pattern of metastatic spreading, as proposed in the seed and soil hypothesis.     

Strenuous exercise aggravates MDMA-induced skeletal muscle damage in mice

The aim of this study was to investigate the influence of ecstasy (MDMA) administration on body temperature and soleus muscle histology in exercised and non-exercised mice. Charles-River mice were distributed into four groups: Control (C), exercise (EX), MDMA treated (M), and M + EX. The treated animals received an i.p. injection (10 mg/kg) of MDMA (saline for C and EX), and the exercise consisted of a 90 min level run at a velocity of 900 m/h, immediately after the MDMA or saline administration. Body temperature was recorded every 30 min via subcutaneous implanted transponder. Animals were sacrificed 1.5, 25.5, and 49.5 h after i.p. injection and the soleus muscles were removed and processed for light and electron microscopy. The MDMA-treated animals showed a significant increase in body temperature (similar in M and M + EX groups), reaching the peak 90 min after i.p. administration; their temperature remained higher than control for more than 5 h. The EX group evidenced a similar and parallel, yet lower temperature increase during exercise and recovery. Morphological signs of damage were rarely encountered in the EX group; they were more pronounced in M group and even aggravated in M + EX group. In conclusion, MDMA and exercise per se increased body temperature but in conjunction did not have a cumulated effect. However, ecstasy and concomitant physical activity might severely accumulate with regard to skeletal muscle toxicity and may lead to rhabdomyolysis.