Somatostatin type V receptor activates c-Jun N-terminal kinases via Galpha(12) family G proteins.

Somatostatin is a neurotransmitter with diverse effects including anti-proliferation in a wide range of normal and neoplastic cells, and occasionally growth stimulatory and neurotrophic actions. Stress-activated protein kinase or c-Jun N-terminal kinase (SAPK/JNK) can also induce growth arrest and occasionally growth stimulation. However, the relationship between somatostatin and SAPK/JNK is less clear. Here we report that the binding of somatostatin to the somatostatin receptor type V (SSTR5) upregulates SAPK/JNK activity. We also show that this activation is mediated by Galpha(12) and Galpha(13). This study demonstrates that SSTR5 is the heptahelical receptor that activates SAPK/JNK via the G(12) family G proteins.

Immunohistochemical detection of apolipoprotein E within prion-associated lesions in squirrel monkey brains.

The interaction of various amyloid precursors and apolipoprotein E (apoE) is important for Congophilic amyloid formation. As for cerebral amyloidoses, although the correlation between amyloid beta protein (Abeta) and apoE in Alzheimer's disease (AD) has been clarified, the interaction of prion protein isoform (PrPsc) and apoE in several types of prion diseases (PDs) has not been examined in detail. ApoE colocalization has been confirmed in Congophilic PrPsc plaques, but to clarify the participation of apoE in the early stage of PDs, apoE deposition in immature lesions without Congophilic amyloid in PDs needs to be examined. In the present study two squirrel monkeys were inoculated with mouse PrPsc derived from sheep scrapie, and showed signs of severe spongiform degeneration. These lesions were immunohistochemically characterized as patchy perivacuolar and diffuse synaptic lesions without Congophilic amyloid. The central portion of the assemblies involving a few patchy perivacuolar lesions was detected by methenamine silver staining and appeared as a plaque-like lesion. ApoE was colocalized in all the plaque-like lesions and in half of the patchy perivacuolar lesions, but not in any diffuse synaptic lesions. These immunohistochemical characteristics indicated that apoE colocalization occurred in moderate mature lesions in PDs, and apoE might play an important role in the aggregation of PrPsc after a conformational change from cellular PrP isoform to PrPsc.

Regulation of the G protein Galphai2 by growth and development in fetal airway epithelium.

Heterotrimeric guanine nucleotide-binding (G) proteins transduce a wide variety of receptor-mediated signals to effectors that are involved in numerous cellular functions, including cell proliferation and differentiation. Thrombin and bombesin/gastrin-releasing peptide mediate their effects via G protein-coupled receptors to regulate lung growth and development. The growth responses of these ligands are likely to be mediated via the Gi subfamily of G proteins, specifically via Galphai2. We hypothesized that Galphai2 is expressed in the lung during ontogeny in a growth-dependent manner, and that Galphai2 regulates cell growth. We demonstrate that Galphai2 is present in the developing lung of Sprague-Dawley rats, and that its expression is enhanced between embryonic Day 19 and postnatal Day 2. The strongest expression occurs in the fetal airway epithelium, and this expression in fetal airway cells is growth-dependent. Galphai2 is localized to the plasma membrane, a location consistent with interaction with growth factor receptors. Inhibition of Gi-family signal transduction by pertussis toxin (10 ng/ml) inhibits DNA synthesis in embryonic Day 19 in fetal airway epithelium. Galphai2 is likely to be a key mediator of growth signals in the developing lung.

A novel system that reports the G-proteins linked to a given receptor: a study of type 3 somatostatin receptor.

SSTR3, a somatostatin (SST) receptor, is an adenylyl cyclase (AC)-inhibiting receptor. To assign the G-protein alpha-subunit (G alpha) linked to this receptor, we created a novel reporter system which utilizes the well-established facts that the C-terminal 5 residues of G alpha are the receptor contact site and G alpha(s) stimulates all subtypes of AC. We constructed chimeric G alpha(s) the C-terminal 5 residues of which were replaced with the corresponding C-terminus of each known G alpha, and examined which chimera confers SSTR3-induced activation of AC. Cellular transfection of SSTR3 and measurement of SST-dependent AC activity through co-transfected chimeric G alpha(s) revealed that SSTR3 recognizes the C-termini of G alpha(i1/2) but not of G alpha(o) or G alpha(z), and those of G alpha(14) and G alpha(16), but not of G alpha(q) or G alpha(11). As predicted by the chimeric G alpha(s), SST-bound SSTR3 stimulated polyphosphoinositide turnover only when G alpha(16) or G alpha(14) was co-transfected. We conclude that the chimeric G alpha(s) system provides a new approach towards the assignment of G-proteins linked to a given receptor.

Negative transactivation of cAMP response element by familial Alzheimer's mutants of APP.

In familial Alzheimer's disease (FAD), missense point mutations V642I/F/G, which co-segregate with the disease phenotype, have been discovered in amyloid precursor APP695. Here, we report that three FAD mutants (FAD-APPs) negatively regulated the transcriptional activity of cAMP response element (CRE) by a G(o)-dependent mechanism, but expression of wildtype APP695 had no effect on CRE. Experiments with various Galpha(s) chimeras demonstrated that Phe-APP coupled selectively to the C-terminus of Galpha(0). Again, wild-type APP695 had no effect on its C-terminus. These data indicate that FAD-APPs are gain-of-function mutants of APP695 that negatively regulate the CRE activity through G(o). This negative transactivation of CRE is the first biochemically analyzed signal evoked by the three FAD-APPs, but not by wild-type APP695, in a whole-cell system. We discuss the significance of constitutive CRE suppression by FAD-APPs, which is potentially relevant to synaptic malplasticity or memory disorders.

G protein-mediated neuronal DNA fragmentation induced by familial Alzheimer's disease-associated mutants of APP.

Missense mutations in the 695-amino acid form of the amyloid precursor protein (APP695) cosegregate with disease phenotype in families with dominantly inherited Alzheimer's disease. These mutations convert valine at position 642 to isoleucine, phenylalanine, or glycine. Expression of these mutant proteins, but not of normal APP695, was shown to induce nucleosomal DNA fragmentation in neuronal cells. Induction of DNA fragmentation required the cytoplasmic domain of the mutants and appeared to be mediated by heterotrimeric guanosine triphosphate-binding proteins (G proteins).

[Clinical evaluation of cefpodoxime proxetil, a new oral cephem, in the treatment of respiratory tract infections with the special reference to community-acquired Streptococcus Pneumoniae infections].

The clinical usefulness of cefpodoxime proxetil (CPDX-PR) was investigated in the treatment of pneumonia and chronic airway infections occurring in patients first visiting our outpatient clinic or those being treated at the outpatient clinic. CPDX-PR was orally administered twice a day after meals at a dose of 100-200 mg for acute respiratory tract infections and at a dose of 200 mg for chronic respiratory tract infections. Excellent, good, fair, and poor responses were observed in 20, 33, 10, and 3 of 66 patients (4 with acute bronchitis, 27 with pneumonia, and 35 with acute exacerbation of chronic airway infection), respectively, demonstrating an 80.3% efficacy rate (53/66). Causative organisms, including Streptococcus pneumoniae, were all eradicated from the patients whose causative organisms were examined over time, although 2 of the patients were superinfected with Pseudomonas aeruginosa. There were no serious adverse reactions or abnormal changes in laboratory test results. It was concluded that CPDX-PR could be used as a first-choice drug for the treatment of respiratory tract infections at an outpatient clinic, and that this drug should acquire greater importance in particular consideration of recent increases in infections with S. pneumoniae.

Myxoid leiomyoma of the vulva mimicking aggressive angiomyxoma.

A case of vulvar leiomyoma with extensive myxoid change in a 40 year old female is described. The tumor had a unique connection with a non-degenerative leiomyoma that compressed the rectum and the bladder. Scattered smooth muscle cells in a loose myxoid stroma were immunoreactive for desmin. Fibroblast-like spindle cells were immunoreactive for vimentin but not for desmin. The initial, although incorrect, pathological diagnosis of the tumor was aggressive angiomyxoma based on the similarity in both clinical and pathological aspects with this more invasive tumor. Myxoid vulvar leiomyoma should also be differentiated from angiomyofibroblastoma. The key to the differential diagnosis is the presence of interlacing smooth muscle cells and an awareness of tendency toward myxoid change in vulvar leiomyomas.

[19-Hydroxyandrostenedione in human ovarian vein measured by GC-MS].

Nineteen-hydroxyandrostenedione (19-OHA) is considered to be an obligatory intermediate of estrogen synthesis. To clarify the role of 19-OHA in the human ovary, the following experiments were undertaken. Ovarian and peripheral vein blood in mid follicular and luteal phase were obtained from 14 women during gynecological surgery. The concentrations of androstenedione (A), testosterone (T), 19-OHA, estrone (E1) and estradiol (E2) were measured by gas chromatography mass spectrometry using deuterium-labeled steroids as internal standard. The effect of human chorionic gonadotropin (hCG) on those steroids was also studied in mid luteal phase. The concentrations of 19-OHA in ovarian vein were 1.20 +/- 0.16 ng/ml (mean +/- SE) in mid follicular and 0.78 +/- 0.18 ng/ml in mid luteal phase. The steroid levels measured in ovarian vein were significantly higher than those in peripheral vein. Though the administration of hCG in mid luteal phase enhanced A and E2 levels in ovarian vein, the levels of T, 19-OHA and E1 were not altered. Significant correlation between the levels of E2 and A was observed while none of the steroids correlated with 19-OHA. These results suggest, for the first time, that 19-OHA is produced and secreted from the human ovary. The question as to the physiological and biosynthetic role of ovarian 19-OHA has to be answered in the future.

[Management of cynomolgus monkey infants after separation from their mothers].

To establish an efficient rearing system for weaned cynomolgus infants, 51 groups composed of 4 weanlings each were formed. Of them each of thirty-eight groups had an adult female "nurse" monkey, who had no kinship with any of the 4 weanlings. The nurse was present during the first 4 weeks after weaning. The daily incidence of watery diarrhea was analyzed to assess the usefulness of the nurse monkey for stabilizing physiological conditions of the weanlings. Diarrheal incidence was significantly lower in the 38 groups with a nurse than in the 13 control groups without a nurse throughout the 4-week period of observation. This trend continued for more than 5 weeks after removal of the nurse. Thus, the time and manpower necessary for treating infant diarrhea were greatly reduced in this rearing system.

[Metabolism of pregnenolone sulfate in feto-placental unit].

In order to study the metabolic fate of circulating pregnenolone sulfate (P5S) during pregnancy, 30 mg of newly synthesized tetra (2,2,4,6)-deuterated P5S was administered to the maternal vein 60 minutes prior to cesarean section at term. All pregnant women were volunteers and had been informed of nature of this study. The placenta, maternal urine and blood samples from maternal vein (MV), umbilical cord (U) were collected and deuterated metabolites were analysed by gas chromatography mass spectrometry with a multiple ion detector. Total amounts of metabolites were measured and the ratio of deuterated steroid to the total amounts were calculated (d%). d% of P5S, 16 alpha OH-P5S, 17 alpha OH-P5S, 20 alpha-dihydro-P5S (20P5S), 20P5 and progesterone (P4) in MV were 84.5, 51.6, 95.5, 85.1, 71.2 and 10.9%, respectively. In the placental tissue, 20P5, 20P4 and P4 were also found and d% of these steroids were calculated as 16.1, 3.2 and 3.1%. Only P4 was found with d% of 11.2% in U. In the urine collected for 2 hours after deuterated P5S administration, P5S (40.6%), 20P5S (56.6%) and pregnanediol (34.8%) were identified. Deuterated C19, C18 steroids were not detected in any of the samples studied. When 30 mg of non labeled P5S was also administered to MV at term, the levels of P5S, 20P5S, P4 and 20P4 in MV rose, but the levels of DHA-S were not changed. These results indicate that the circulating P5S in MV can be a precursor of 20P5S, 17P5S, 16P5S, 20P4 and P4, but can not be the precursor of C19, C18 steroid.

[Clinical evaluation of cefoxitin in treatment of infections in obstetric and gynecologic field (author's transl)].

Ten patients (8 with moderate or severe infections, 2 for prevention of postoperative infections) were treated with cefoxitin. The patients were given cefoxitin of 2 approximately 9 g, given once, or in 2 approximately 3 divided doses. Clinical efficacy was good in 7 cases, fair in 2 and poor in 1. Transient nausea and vomiting occurred in 1 patient when a direct intrauterine injection (1 g of cefoxitin) was given, however, no side effects were observed in the other patients. The result of this study demonstrates that cefoxitin when given massively is effective in achieving bacteriologic and clinical cure in treatment of infections and for prevention of postoperative infections in the field of obstetrics and gynecology.