Mutation of the conserved N-terminal cysteine (Cys92) of human presenilin 1 causes increased A beta42 secretion in mammalian cells but impaired Notch/lin-12 signalling in C. elegans

The presenilin proteins are involved in the proteolytic processing of transmembrane proteins such as Notch/lin-12 and the beta-amyloid precursor protein (betaAPP). Mutation of a conserved cysteine (Cys60Ser) in the C. elegans presenilin sel-12 has a loss-of-function effect on Notch/lin-12 processing similar to that of null mutations in sel-12. In contrast, in mammalian cells, most missense mutations increase gamma-secretase cleavage of betaAPP. We report here that mutation of this conserved cysteine (Cys92Ser) in human presenilin 1 confers a loss-of-function effect in C. elegans, but causes increased A beta42 secretion in mammalian cells. These data suggest that the role of presenilins in Notch/lin-12 signalling and betaAPP processing are either separately regulated activities or independent activities of the presenilins.

Nicastrin modulates presenilin-mediated notch/glp-1 signal transduction and betaAPP processing

Nicastrin, a transmembrane glycoprotein, forms high molecular weight complexes with presenilin 1 and presenilin 2. Suppression of nicastrin expression in Caenorhabditis elegans embryos induces a subset of notch/glp-1 phenotypes similar to those induced by simultaneous null mutations in both presenilin homologues of C. elegans (sel-12 and hop-1). Nicastrin also binds carboxy-terminal derivatives of beta-amyloid precursor protein (betaAPP), and modulates the production of the amyloid beta-peptide (A beta) from these derivatives. Missense mutations in a conserved hydrophilic domain of nicastrin increase A beta42 and A beta40 peptide secretion. Deletions in this domain inhibit A beta production. Nicastrin and presenilins are therefore likely to be functional components of a multimeric complex necessary for the intramembranous proteolysis of proteins such as Notch/GLP-1 and betaAPP.

Mutation of conserved aspartates affects maturation of both aspartate mutant and endogenous presenilin 1 and presenilin 2 complexes

Presenilin (PS1 and PS2) holoproteins are transiently incorporated into low molecular weight (MW) complexes. During subsequent incorporation into a higher MW complex, they undergo endoproteolysis to generate stable N- and C-terminal fragments. Mutation of either of two conserved aspartate residues in transmembrane domains inhibits both presenilin-endoproteolysis and the proteolytic processing of beta-amyloid precursor protein and Notch. We show that although PS1/PS2 endoproteolysis is not required for inclusion into the higher MW N- and C-terminal fragment-containing complex, aspartate mutant holoprotein presenilins are not incorporated into the high MW complexes. Aspartate mutant presenilin holoproteins also preclude entry of endogenous wild type PS1/PS2 into the high MW complexes but do not affect the incorporation of wild type holoproteins into lower MW holoprotein complexes. These data suggest that the loss of function effects of the aspartate mutants result in altered PS complex maturation and argue that the functional presenilin moieties are contained in the high molecular weight complexes.

Limited genetic susceptibility to severe Graves' ophthalmopathy: no role for CTLA-4 but evidence for an environmental etiology

Graves' disease (GD) is an autoimmune thyroid disease (AITD) characterized by hyperthyroidism and by the occurrence of a distinctive ophthalmopathy (orbitopathy), which presents with varying degrees of severity. Graves' disease clusters in families but the importance of heredity in the pathogenesis of the associated ophthalmopathy is unclear. We have studied the family history of 114 consecutive, ethnically mixed patients with severe Graves' ophthalmopathy (GO). Patients were selected by unambiguous single ascertainment. Seventy-seven percent of patients were female and 59% smoked. The mean age at onset of their GD was 43 years (range 17-78 years). Forty-one patients (36%) had a family history of AITD, defined as a first- and/or a second-degree relative affected with either Graves' disease (GD) or Hashimoto's thyroiditis (HT). The segregation ratio for AITD in nuclear families in our ascertained Graves' ophthalmopathy families was 0.07 (0.12 in Caucasians only). Hence, the higher prevalence of AITD among relatives of Graves' ophthalmopathy patients agreed with the known genetic predisposition to AITD and this predisposition was stronger in women than in men. However, only 3 of the 114 patients had a family history of severe Graves' ophthalmopathy (all second-degree relatives) and the segregation ratio for GO was 0. These data did not support a major role for familial factors in the development of severe Graves' ophthalmopathy distinct from Graves' disease itself. In addition, we tested 4 candidate genes, human leukocyte antigen (HLA), tumor necrosis factor-beta (TNF-beta), CTLA-4 and the thyrotropin receptor (TSHR), for association with Graves' ophthalmopathy. These were negative except for the HLA and CTLA-4 genes, which were found to be weakly associated with GO giving similar relative risk (RR) as in GD patients without ophthalmopathy. These data suggested that environmental factors, rather than major genes, were likely to predispose certain individuals with AITD to severe Graves' ophthalmopathy. Smoking remains one example of such potential external insults.

Lipopolysaccharide-induced expression of inducible nitric oxide synthase in the guinea pig organ of Corti

The purpose of the investigation was to ascertain whether inoculation of bacterial lipopolysaccharide (LPS) into the cochlea of the guinea pig could elicit formation of inducible nitric oxide synthase (iNOS). Immunohistochemical study revealed that immunoreactivity to iNOS was seen below outer hair cells representing nerve fibers and synaptic nerve endings. iNOS-staining could also be observed in phalangeal dendrites of Deiter's cells pointing to the cuticular membrane, Hensen's cells and on stria vascularis 48 h after inoculation with LPS. Immunohistochemical investigation with a specific anti-nitrotyrosine antibody also revealed intense immunoreactivity identical to that of iNOS, suggesting formation of peroxynitrite in the organ of Corti by the reaction of NO with O(2)(-). On the basis of these findings, it can be concluded that NO together with O(2)(-), which form the more reactive peroxynitrite, are the most important pathogenic agents in LPS-induced damage of cochlea in the guinea pig.

Localization of soluble guanylate cyclase activity in the guinea pig inner ear

The aim of this study was to characterize the nitric oxide (NO) receptor soluble guanylate cyclase (sGC), to determine the cells targeted by NO and to elucidate the function of the NO/cGMP pathway in the inner ear. sGC activity in the inner ear was localized by immunohistochemical detection of NO-stimulated cGMP. Soluble guanylate cyclase activity in the cochlea was detected in the nerve endings underneath the outer and inner hair cells, supporting cells, stria vascularis and vessels. In the vestibular organs, sGC activity was detected in the cytoplasm of sensory cells, nerve fibres, dark cells and transitional cells and vessels. These findings suggest that the NO/cGMP pathway may be involved in regulatory processes in neurotransmission, blood flow and inner ear fluid homeostasis.

Presenilins interact with armadillo proteins including neural-specific plakophilin-related protein and beta-catenin

Missense substitutions in the presenilin 1 (PS1) and presenilin 2 (PS2) proteins are associated with early-onset familial Alzheimer's disease. We have used yeast-two-hybrid and coimmunoprecipitation methods to show that the large cytoplasmic loop domains of PS1 and PS2 interact specifically with three members of the armadillo protein family, including beta-catenin, p0071, and a novel neuronal-specific armadillo protein--neural plakophilin-related armadillo protein (NPRAP). The PS1:NPRAP interaction occurs between the arm repeats of NPRAP and residues 372-399 at the C-terminal end of the large cytoplasmic loop of PS1. The latter residues contain a single arm-like domain and are highly conserved in the presenilins, suggesting that they form a functional armadillo protein binding site for the presenilins.

Presenilin mutations associated with Alzheimer disease cause defective intracellular trafficking of beta-catenin, a component of the presenilin protein complex

The presenilin proteins are components of high-molecular-weight protein complexes in the endoplasmic reticulum and Golgi apparatus that also contain beta-catenin. We report here that presenilin mutations associated with familial Alzheimer disease (but not the non-pathogenic Glu318Gly polymorphism) alter the intracellular trafficking of beta-catenin after activation of the Wnt/beta-catenin signal transduction pathway. As with their effect on betaAPP processing, the effect of PS1 mutations on trafficking of beta-catenin arises from a dominant 'gain of aberrant function' activity. These results indicate that mistrafficking of selected presenilin ligands is a candidate mechanism for the genesis of Alzheimer disease associated with presenilin mutations, and that dysfunction in the presenilin-beta-catenin protein complexes is central to this process.

[Biological effects of space flight on purple nonsulfur photosynthetic bacteria]

OBJECTIVE

To study biological effects of space flight on purple nonsulfur photosynthetic bacteria.

METHODS

Two purple nonsulfur photosynthetic bacteria, Rhodopseudomonas palustris H3 and Rhodobacter sphaeroides ZGY, were carried on satellite for 15 days and some of their biological effects were studied after recovery.

RESULTS

In space condition, survival rate of bacteria was promoted. The purification of organic wastewater, removal of nitrite, degradation of phenol and decolorization of acid red B were enhanced, and the resistance of both strains to medicine was stable.

CONCLUSION

The major morphological and physiological characteristics of loaded strains H3-S and ZGY-S were not changed after space flight.

The presenilin 1 protein is a component of a high molecular weight intracellular complex that contains beta-catenin

The presenilin (PS) genes associated with Alzheimer disease encode polytopic transmembrane proteins which undergo physiologic endoproteolytic cleavage to generate stable NH2- and COOH-terminal fragments (NTF or CTF) which co-localize in intracellular membranes, but are tightly regulated in their stoichiometry and abundance. We have used linear glycerol velocity and discontinuous sucrose gradient analysis to investigate the distribution and native conformation of PS1 and PS2 during this regulated processing in cultured cells and in brain. The PS1 NTF and CTF co-localize in the endoplasmic reticulum (ER) and in the Golgi apparatus, where they are components of a approximately 250-kDa complex. This complex also contains beta-catenin but not beta-amyloid precursor protein (APP). In contrast, the PS1 holoprotein precursor is predominantly localized to the rough ER and smooth ER, where it is a component of a approximately 180-kDa native complex. PS2 forms similar but independent complexes. Restricted incorporation of the presenilin NTF and CTF along with a potentially functional ligand (beta-catenin) into a multimeric complex in the ER and Golgi apparatus may provide an explanation for the regulated accumulation of the NTF and CTF.

Localization of nitric oxide synthase isoforms (I, II and III) in the endolymphatic sac of the guinea pig

The localization of nitric oxide (NO) synthase (NOS) isoforms was examined in the endolymphatic sac (ES) of the pigmented guinea pig by indirect immunohistochemistry. The cytoplasm of the epithelial cells in the ES showed both NOS-I and -III immunoreactivity, whereas their nuclei appeared negative. NOS-III staining was also observed in the endothelial lining of the blood vessels. These findings support the hypothesis that NO in the epithelial cells may play an important role for the active intracellular transport of the endolymph and ion. NO may also be crucially involved in the regulation of ES blood flow. Immunostaining for NOS II revealed no reactivity in general, while in lipopolysaccharide-inoculated animals, intense reactivity was found in the cytoplasm of the ES epithelial cells as well as macrophages in the lumen. Thus it has been indicated that NO also may play an important role in the immunodefensive mechanisms in the ES.

Effect of streptomycin on the otoconial layer of the guinea pig

The effects of streptomycin on the otoconial layer of the adult guinea pig were investigated using scanning electron microscopy. Administration of streptomycin induced a reduction of otoconia with formation of giant otoconia. These phenomena reached their maximum 4 weeks after the cessation of streptomycin intoxication in the utricle and between 2 and 6 weeks after in the saccule. Otoconia began to recover in the utricle 4 weeks and in the saccule 6 weeks after the cessation of streptomycin intoxication with an increasing number of small otoconia. Eight or 10 weeks after the cessation of streptomycin intoxication, the otoconial layer has completely recovered in both the utricle and saccule.

[Formation and calcium incorporation of giant otoconia of the guinea pig after streptomycin intoxication]

The mechanisms for the formation and fate of giant otoconia following streptomycin (SM) intoxication were investigated in adult pigmented guinea pigs by scanning electron microscopy. Calcium turnover into otoconia has also been studied by using tetracycline as a tracer. The administration of SM induced the reduction of otoconia with the formation of giant otoconia. The giant otoconia had a multifaceted morphology in their early developmental period. This type of otoconia showed entire fluorescence indicating existence of calcium uptake. They then grew up to the transitional type and finally to the cylindrical type. The giant otoconia were thought to be formed mainly by dissolution of normal otoconia due to the loss of environmental calcium followed by recrystallization as giant crystals. The transitional type of giant otoconia showed less calcium ion uptake and the removal of calcium from the giant otoconia caused their quick disappearance. These phenomena might be closely related to the otoconial dynamics which may regulate calcium ion homeostasis of endolymph.

Electron probe X-ray microanalysis of otoconia in the guinea pig inner ear

By using the electron probe X-ray microanalysis technique, the elemental composition of otoconia was analyzed in the normal adult pigmented guinea pig. In the X-ray spectra of otoconia, the most abundant element was Ca, but significant peaks for P, S, Cl and K were also detected. The comparison of the elemental composition in the utricular and saccular otoconia did not show any significant difference. Regression analysis revealed that the concentrations of Ca and K are related by a linear function in both the utricular and saccular otoconia. Analysis of otoconia of different sizes showed that there were no differences in Ca concentration in small, normal and large otoconia. The comparison of other elemental compositions revealed that P, S, Cl and K in the central part of saccular small otoconia showed higher concentrations than those of normal or large otoconia. P, S, Cl and K in the utricular small otoconia showed relatively higher concentrations. These findings may indicate that the small otoconia are immature or newly generated.

Electron probe X-ray microanalysis of otoconia in guinea pig inner ear: a comparison between young and old animals

Using the electron probe X-ray microanalysis technique, the elemental composition of otoconia was analysed in both young and old normal pigmented guinea pigs. Calcium concentration in both the utricular and the saccular otoconia was lower in the old animals, which indicates that the loss of calcium from otoconia and/or decrease in calcium ion uptake may occur in the old animals. The present study has established that calcium and other elements (P, S, Cl and K) in the otoconia of the young animals are related via a linear function, indicating that P, S, Cl and K are present in the mineral phase of the otoconia. The associations of Ca-P, Ca-K and Ca-S are not maintained in the old animals. It has been suggested that the aging phenomenon may influence the ionic metabolism in the vestibular end organs resulting in the altered mineral composition of otoconia.

Formation and fate of giant otoconia of the guinea pig following streptomycin intoxication

Formation and fate of abnormal (giant) otoconia of the guinea pig following streptomycin intoxication were investigated using scanning electron microscopy. The giant otoconia formed as multifaceted morphology in their early developmental period. They grew up the the transitional type and finally to the cylindrical type. It has been suggested that the giant otoconia found following streptomycin intoxication may be formed mainly by dissolution of normal otoconia due to the loss of environmental calcium, followed by recrystallization as giant crystals. These phenomena seemed to be closely related to the otoconial dynamics which may regulate calcium ion homeostasis of the endolymph.

In vitro calcium ion turnover in otoconia of the guinea pig

In vitro calcium ion turnover into otoconia of adult guinea pigs was investigated by the use of tetracycline. The incubation in tetracycline in vitro clearly demonstrated the deposition of tetracycline (fluorescence) on the outer surface of otoconia. Levels of Ca2+ uptake in utricular otoconia were higher than those in saccular otoconia. In vitro uptake and/or exchange of Ca2+ was greater in fluid with a high K+/Na+ ratio than in fluid in which the ratio was low. It has been thus indicated that a high K+/Na+ ratio in normal endolymph should be more suitable for Ca2+ uptake and/or exchange to maintain the ionic environment in the inner ear. Sodium dodecyl sulfate treatment of otoconia increased the Ca2+ uptake. The ability of the otoconia to take up Ca2+ appears to decline with age. It has been indicated that the organic matrix of otoconia may be one of the inhibitory factors for Ca2+ uptake in old animals.

Polychromatic labeling of otoconia for the investigation of calcium turnover

The calcium ion turnover into otoconia of adult guinea pigs was investigated by the use of different fluorochromes, i.e. tetracycline (TC), calcein (Cal) and alizarin complexone (AC). The administration of all fluorochromes induced yellow (TC), green (Cal) and red (AC) fluorescence on the outer surface of otoconia, respectively. Sequential polychromatic labeling with AC followed by TC induced only red fluorescence after 1 week administration of TC, combined fluorescence after 2 weeks administration of TC and only yellow fluorescence after more than 3 weeks of administration of TC. The otoconia labeled with both AC and TC showed red fluorescence on the side faces of otoconia and yellow fluorescence on the terminal faces. These results may indicate the existence of a dynamic exchange of calcium ions in the otoconia and this exchange is mainly restricted to the terminal faces. The sequential polychromatic labeling may thus be of great use for the further investigation of the calcium dynamics of otoconia.

Intracerebral administration of mineralocorticoid receptor antisense oligonucleotides attenuate adrenal steroid-induced salt appetite in rats

The amygdala contains mineralocorticoid (MR) and glucocorticoid receptors (GR) involved in the arousal of salt appetite. In the present investigation, MR antisense oligonucleotides injected into the amygdala inhibited salt appetite induced by systemic desoxycorticosterone (DOCA) but not adrenalectomy (ADX). In contrast, GR antisense or scrambled oligonucleotides had no effect on stimulated salt intake. MR antisense oligomers also decreased MR but not GR in amygdala, whereas GR antisense oligomers decreased GR but not MR. Immunocytochemical labelling of the biotinylated MR antisense revealed that distribution of the oligomer was restricted to the injection site, with incorporation in neurons and neighboring glial cells. Together, these data demonstrate the utility of receptor antisense oligonucleotides for investigating the central actions of adrenal steroids and the role of amygdala in MR in DOCA-induced sodium intake.

Incorporation of tetracycline into otoconia of the guinea-pig following streptomycin intoxication

The effects of streptomycin on the calcium ion turnover into otoconia of adult guinea-pigs investigated by the use of tetracycline. The oral administration of tetracycline induced the deposition of tetracycline (fluorescence) on the outer surface of otoconia indicating the existence of dynamic exchange and/or uptake of calcium ions in the otoconia. The significant finding is that streptomycin specifically interfered with calcium uptake into the otoconia which indicated that the decrease in calcium uptake caused by streptomycin may be closely related to the loss of otoconia as well as to a decrease in the calcium contents of otoconia. The decrease in calcium incorporation into otoconia caused by streptomycin was recovered within 6 weeks after the last injection of streptomycin. The number of otoconia with fluorescence in the central portion as well as their outer surface was increased. It is therefore suggested that the recovery of calcium uptake as well as new otoconial regeneration may play an important role for the recovery from loss of otoconia.

Uptake of tetracycline in otoconia of the guinea pig

Calcium ion turnover in the otoconia of adult guinea pigs was investigated by observing the uptake of tetracycline. Oral administration of tetracycline resulted in the deposition of tetracycline (fluorescence) on the outer surface of otoconia, indicating the occurrence of dynamic exchange and/or uptake of calcium ions in the otoconia. Prolonged administration of tetracycline induced with fluorescence deposition in the central portion as well as on the surface of the otoconia. These findings suggest the occurrence of neogenesis, regeneration and/or growth of otoconia even in adult animals.

Araliasaponins XII-XVIII, triterpene saponins from the roots of Aralia chinensis

Seven new oleanane-type saponins, named araliasaponins XII-XVIII, were isolated from the roots of Aralia chinensis, together with 14 known triterpene saponins. On the basis of the chemical and spectroscopic evidence, the structures of these new saponins were elucidated as follows: 3-O-beta-D-glucopyranosyl(1-->3)-[beta-D -glucopyranosyl(1-->2)]-alpha-L-arabinopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl ester, 3-O-beta-D-glucopyranosyl(1-->3)-[beta-D-xylopyranosyl (1-->2)]-alpha-L-arabinopyranosyl oleanolic acid 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl ester, 3-O-beta-D -glucopyranosyl(1-->3)-[beta-D-galactopyranosyl(1-->2)] -beta-D-glucopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl ester, 3-O-beta-D-glucopyranosyl(1-->3)-[beta-D -xylopyranosyl(1-->2)]-beta-D-glucopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl ester, 3-O-beta-D -glucopyranosyl(1-->3)-[beta-D-galactopyranosyl (1-->2)]-beta-D-galactopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl ester, 3-O-alpha-L -arabinofuranosyl(1-->4)-[beta-D-glucopyranosyl (1-->2)]-beta-D-glucuronopyranosyl oleanolic acid dimethyl ester and 3-O-alpha-L-arabinofuranosyl (1-->4)-[beta-D-glucopyranosyl(1-->2)]-beta-D -glucuronopyranosyl oleanolic acid 28-O-beta-D -glucopyranosyl(1-->6)-beta-D-glucopyranosyl methyl ester, respectively.

Araliasaponins I-XI, triterpene saponins from the roots of Aralia decaisneana

Seven new oleanane-type and four new ursane-type triterpene saponins, named araliasaponins I-XI were isolated from the roots of Aralia decaisneana, together with four known triterpene saponins. On the basis of the chemical and spectroscopic evidence, the structures of these new saponins were elucidated as follows: 3-O-beta-D-xylopyranosyl-(1-->3)-beta-D- glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->2)]-alpha-L- arabinopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl ester, 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L- arabinopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1-->6)-beta-D- glucopyranosyl ester, 3-O-beta-D-glucopyranosyl-(1-->3)-[beta-D- xylopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3-O-beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->2)]-beta-D- glucopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl ester, 3-O-beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->2)]-beta-D- galactopyranosyl oleanolic acid, 3-O-beta-D-glucopyranosyl-(1-->3)-[beta-D- xylopyranosyl-(1-->2)]-beta-D-galactopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl ester, 3-O-beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->2)]-beta-D- galactopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester, 3-O-beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->2)]- alpha-L-arabinopyranosyl ursolic acid 28-O-beta-D-glucopyranosyl ester, 3-O-beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->2)]-alpha-L - arabinopyranosyl ursolic acid, 3-O-beta-D-glucopyranosyl-(1-->3)-alpha-L-arabinopyranosyl ursolic acid 28- O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester and 3-O-beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->2)]- beta-D-glucopyranosyl ursolic acid 28-O-beta-D-glucopyranosyl ester.

[Epidemiologic studies on three episodes of acute bacillary dysentery outbreak]

Three episodes of illness outbreak, with major symptoms of acute abdominal pain and diarrhea, occurred in 1990 to 1991 in the army forces stationed in Beijing. Bacillary dysentery outbreak caused by Shigella dysentariae were confirmed with epidemiological investigations and pathogen identification. Drug sensitivity tests with Kirby-Bauer method for the strain isolated showed it had obvious resistance to 13 of 14 kinds of antibiotics tested. Detection of plasmid with Birnboim method showed most of the strains had R-plasmid of 120-140 Md and few had small plasmid. It suggested inherent connection between drug-resistance of the strains and plasmid.

[The protective effects of cilazapril of chronic hypoxic pulmonary hypertension and hypoxemia in rats]

This study attempted to research the protective effects of cilazapril, a new ACE inhibitor, on chronic hypoxic pulmonary hypertension and hypoxemia in rats. The mean pulmonary arterial pressure (mPAP) of the rats after hypoxia and injection with 1% Fecl3 via the tail veins for 4 weeks increased significantly but its PaO2 decreased separately. Cilazapril effectively protected mPAP increase and PaO2 decrease in rats treated with Cilazapril (0.5 mg/d) by suppressing the lung injury of TNF and oxygen free radical.

Isolation, mapping, DNA sequence and RFLPs studies of random single-copy DNA segments on human X chromosome

Using the total human/mouse DNA as the probe, screening has been carried out three times with in situ plaque hybridization to obtain the single-copy DNA sequence from the human X chromosome genomic library. The effective rate of screening is 1.45%. DNAs from clones containing single-copy inserts have been analyzed by a panel of hybrid cells with or without human X chromosome. Three segments, designated by DXFD52,73,75, are mapped to the X chromosome. DXFD52 has been precisely localized on Xq12-q13 with in situ chromosomal hybridization. DXFD52 has been partially sequenced. The results indicate that DXFD52 is a new isolated single-copy segment on the X chromosome. Great progress in the RFLPs study with DXFD52 has been achieved in the population of Chongqing, Sichuan Province. The results show that the DXFD52 can be used to detect the RFLP with Hind III, Bgl II, and Hinf I. DXFD52 will be a potential "landmark" for the construction of the complete linkage map of human genome and the analysis of genomic sequence. And also, the results provide the experience in the development of a useful DNA probe to be applied to diagnosing X-linked disorders.

[Morphological study on 40 cases of alcoholic liver disease]

Morphological changes in liver biopsies from 40 alcoholic patients were studied, 20 of which being ordinary alcoholics (40-80g ethanol/day) and the other 20 being heavy drinkers (above 80g ethanol/day for over 20 years). All being male who have neither type B nor type C hepatitis. The basic morphological changes observed being: 1. Liver cell degeneration including fatty degeneration & focal ballooning, decrease in liver cell size, occasional giant mitochondrion and Mallory's body formation. 2. Focal necrosis with neutrophil infiltration. 3. Pericellular fibrosis of liver cells, hepatic fibrosis and early cirrhosis. Alcoholic liver disease can be divided into 5 types: I. alcoholic fatty liver (AFL), II. alcoholic hepatitis (AH), III. alcoholic hepatic fibrosis (AHF), IV. alcoholic liver cirrhosis (ALC), V. slight alcoholic liver disease (SALD). The degree of liver damage (liver cell necrosis and hepatic fibrosis) is closely related to the amount of daily ethanol intake. The progression of liver damage observed in our study is much milder than reports from Europe, the U.S. and Japan.

Medial region of the amygdala: involvement in adrenal-steroid-induced salt appetite

We report the following observations: first that cell body damage induced by ibotenic acid within the medial region of the amygdala resulted in the abolition of corticosterone-potentiated, aldosterone-induced salt appetite. Sodium depletion-induced salt appetite was not impaired by the lesion, nor was angiotensin-dependent salt appetite via captopril treatment. These results provide evidence that the medial region of the amygdala has a major role in the natriorexigenic effects of the adrenal steroids.

[Effect of atrial natriuretic peptide on angiotensin II--and water deprivation-induced drinking behavior in rats]

Atrial natriuretic peptide (ANP) present in the brain has been reported to have profound effects on water and salt metabolism. This study was designed to observe the effect of intracerebroventricular (ICV) injection of ANP on drinking behavior of rats, induced by centrally administered angiotensin II (Ang II) and 24-hours water deprivation, by using a T-maze to measure the speed they ran in a runway for water rewards. In 24-hours water deprived rats ICV injection of ANP resulted in a significant decrease of either running speed or water intake. Drinking behavior induced by ICV injection of Ang II in normally hydrated rats was also significantly inhibited by a prior injection of ANP. These findings suggest that ANP in the brain plays an important role in the central control of drinking behavior.

Neuroendocrinology of atrial natriuretic polypeptide in the brain

It has been demonstrated that atrial natriuretic polypeptide (ANP), or atriopeptin, is synthesized and stored not only in the cardiac atrial myocyte but also in the central nervous system, especially in the hypothalamus. ANP may play an important role in the regulation of fluid and electrolyte balance and blood pressure in the peripheral and central nervous systems. Some of the biological actions of ANP are opposite to those of angiotensin II and arginine vasopressin in the central nervous system. However, the mechanism of action of ANP remains, in a large part, to be defined.

Structure of Tripterygic Acid A: A New Triterpene of Tripterygium wilfordii

From roots of TRIPTERYGIUM WILFORDII used in Chinese folk medicine, a new ursane-triterpene named tripterygic acid A was isolated along with a known triterpene and their structures were elucidated by means of spectral analysis and chemical transformation.

Brain cholecystokinin as a satiety peptide

Injection of 0.08 microgram/kg of CCK-8 into the anterior cerebral ventricles of the rat produced a significant depression in the rat's motivation for food for at least one-half hour, as measured by running speed to food rewards in a runway and by food intake in a test-meal in the rat's home cage. Doses of 0.04 microgram/kg were ineffective and doses of 0.06 microgram/kg intermediate. There was no effect of 0.08 microgram/kg on running speed to water rewards. Intraperitoneal doses of 8.0 micrograms/kg also suppressed running speed and eating.

Together intracranial angiotensin and systemic mineralocorticoid produce avidity for salt in the rat

Rats that have no need for sodium will run to small rewards of 3% NaCl solution in a runway after they have been treated with both a mineralocorticoid and angiotensin II. When given alone at the low doses used here, neither the mineralocorticoid nor the angiotensin produce the behavior. This result encourages the idea that it is a synergy of the hormones of sodium conservation, angiotensin and aldosterone, that apprises the brain of the need for salt and generates the appetite for the taste of salt.

The failure of ventricular sodium to control sodium appetite in the rat

Dilution of CSF sodium by infusion of hyperosmotic mannitol into the cerebral ventricles of the rat does not evoke a salt appetite, nor does the addition of sodium to the CSF of the rat suppress the preexisting salt appetites produced by the hormones of sodium conservation or by adrenalectomy. CSF sodium concentration does not control sodium appetite in the rat. The proposal that it does so in sheep should not be generalized to other species without caution.