Calciseptine binding to a 1,4-dihydropyridine recognition site of the L-type calcium channel of rat synaptosomal membranes

Calciseptine (CaS) is a natural peptidic L-type Ca2+ channel blocker consisting of 60 amino acids with four disulfide bonds. The effects of synthetic CaS on the binding of various ligands to Ca2+ channels of rat brain synaptosomal membranes were studied. The membranes possessed specific binding sites for L-type Ca2+ channel ligands [3H]nitrendipine, [3H]diltiazem and [3H]verapamil, derivatives of 1,4-dihydropyridine, benzothiazepine and papaverine, respectively, and also for N-type Ca2+ channel ligand omega-[125I]-conotoxin GVIA (omega-[125I]CTX). Lineweaver-Bulk plot analysis disclosed that CaS competitively inhibited the binding of [3H]nitrendipine, with maximal binding capacity of 0.19 pmol/mg protein and dissociation constant (Kd) of 290 nM, being about 10(3) times the Kd value of [3H]nitrendipine. Similar to nitrendipine, CaS noncompetitively enhanced the binding of [3H]diltiazem, but did not affect the binding of [3']verapamil. CaS at up to 10.0 microM did not affect the binding of omega-[125I]CTX. These observations indicate that CaS shares the properties of 1,4-dihydropyridine derivatives, and allosterically modulates the binding of other L-type Ca2+ channel ligands.

Beneficial effect of hepatic stimulatory substances on the survival of intrasplenically transplanted hepatocytes

Intrasplenic hepatocyte transplantation has been demonstrated to have a tentative role in treating experimental liver disease, but methods for promoting the rapid proliferation of intrasplenic hepatocytes are still quite limited. In this study, hepatic stimulatory substances (HSS) obtained from regenerating porcine livers were injected directly into the subcutaneously translocated spleens of recipient rats that had received intrasplenic hepatocyte transplantation. The clusters of intrasplenic hepatocytes contained more than 100 cells, and formed cord structures at 2 wk after transplantation, and the hepatocytes still survived at 6 wk in the HSS-treated rats. In contrast, the clusters contained less than 10 hepatocytes at 2 wk after transplantation, and no surviving hepatocytes was observed at 4 and 6 wk in control rats. Additionally, marked proliferation of bile ductular-like structures appeared around the clusters of surviving hepatocytes in the splenic red pulp of the HSS-treated rats, but were not found in control rats at 4 and 6 wk after transplantation.

Subgenomic RNA sequence of human astrovirus supports classification of Astroviridae as a new family of RNA viruses

We report the sequence of the subgenomic RNA of human astrovirus serotype 2. This 2,484-nucleotide RNA contains a single open reading frame, which encodes a protein with a predicted molecular mass of 88 kDa. We propose that this protein is the 90-kDa capsid precursor observed in infected cells. The deduced protein sequence does not contain conserved amino acid patterns reported for the capsid proteins of picornaviruses or caliciviruses, consistent with the classification of astroviruses as a new family of RNA viruses, designated Astroviridae.

Similarity of the VP4 protein of human rotavirus strain 116E to that of the bovine B223 strain

Rotavirus strain 116E was isolated from the fecal specimen of a newborn infant from New Delhi who had no symptoms of diarrhea. The strain could not be P typed using the PCR method recently developed in our laboratory so we have sequenced the 4th gene segment that encodes the VP4 protein using viral transcript RNA prepared in vitro. This gene is 2353 base pairs in length and codes for a protein 772 amino acids long which begins with a methionine initiation codon at nucleotides 11 to 13 and ends with a single termination codon at nucleotides 2327 to 2329. Northern blot analysis demonstrates that the VP4 protein of this strain is encoded by genome segment 4. This gene is closely related to the VP4 gene of the bovine B223 strain (P type 11) at both the nucleotide (90.8% identity) and amino acid (92.2% identity) levels, but is unique from those of strains from P types 1 to 10. The close relatedness of the VP4 proteins of strains 116E and B223 is demonstrated by the amino acid composition of the potential trypsin cleavage sites and their flanking sequences, the size of the cleavage fragments, and conservation of most cysteine and proline residues. Comparative amino acid analyses of the variable regions thought to be important in VP4 antigenicity are consistent with the hypothesis that strain 116E may represent the first reported human P type 11 strain.

A mutational analysis of killer toxin resistance in Saccharomyces cerevisiae identifies new genes involved in cell wall (1-->6)-beta-glucan synthesis

Recessive mutations leading to killer resistance identify the KRE9, KRE10 and KRE11 genes. Mutations in both the KRE9 and KRE11 genes lead to reduced levels of (1-->6)-beta-glucan in the yeast cell wall. The KRE11 gene encodes a putative 63-kD cytoplasmic protein, and disruption of the KRE11 locus leads to a 50% reduced level of cell wall (1-->6)-glucan. Structural analysis of the (1-->6)-beta-glucan remaining in a kre11 mutant indicates a polymer smaller in size than wild type, but containing a similar proportion of (1-->6)- and (1-->3)-linkages. Genetic interactions among cells harboring mutations at the KRE11, KRE6 and KRE1 loci indicate lethality of kre11 kre6 double mutants and that kre11 is epistatic to kre1, with both gene products required to produce the mature glucan polymer at wild-type levels. Analysis of these KRE genes should extend knowledge of the beta-glucan biosynthetic pathway, and of cell wall synthesis in yeast.

Nucleotide sequence variation in Pneumocystis carinii strains that infect humans

The nucleotide sequences of a portion of the large-subunit mitochondrial rRNA gene of Pneumocystis carinii derived from 12 patients were examined. Five sequences were found to be identical to the prototype sequence reported by Sinclair et al. (K. Sinclair, A. E. Wakefield, S. Banerji, and J. M. Hopkin, Mol. Biochem. Parasitol. 45:183-184, 1991). Six sequences differed from the prototype sequence at one to three positions. The remaining sequence was markedly different from the prototype sequence and appeared to be a hybrid of the human and rat P. carinii sequences. The results of this study indicate the existence of multiple P. carinii strains infecting humans and suggest that coinfections of animal and human P. carinii strains in the same host are possible.

Absence of a growth hormone effect on rat soleus atrophy during a 4-day spaceflight

The objectives of the present study were to determine the size and enzyme properties of soleus fibers of rats subjected to a 4-day spaceflight (National Aeronautics and Space Administration, STS-41) and the effects of exogenous growth hormone (GH) on the atrophic response of the muscle. Four groups of rats were studied: 1) control (Con), 2) Con plus GH treated (Con + GH), 3) flight (Fl), and 4) F1 plus GH treated (Fl + GH). Cross-sectional area and the activities of succinate dehydrogenase and myofibrillar adenosinetriphosphatase (ATPase) were determined in fibers identified in frozen serial cross sections. Fibers were categorized immunohistochemically as slow, fast, or slow-fast on the basis of their reaction with slow and fast myosin heavy-chain (MHC) monoclonal antibodies. Fibers also were categorized as light or dark on the basis of their staining for ATPase at pH 8.6. After the 4-day flight, mean body weight was significantly decreased compared with control. The absolute and relative (muscle wt/body wt) soleus weights were significantly smaller in the Fl and Fl + GH rats compared with their respective ground-based controls. In both flight groups, the cross-sectional area of the light ATPase fibers was significantly smaller (approximately 30%) than control. Three of 11 flight rats had a higher proportion of fibers expressing both slow and fast MHCs than expected on the basis of the fiber type distribution in the 11 control rats. Mean fiber succinate dehydrogenase and ATPase activities were similar among the four groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of beraprost sodium, a stable analogue of prostacyclin, on hyperplasia, hypertrophy and glycosaminoglycan synthesis of rat aortic smooth muscle cells

The effects of beraprost sodium, a stable analogue of prostacyclin, on the syntheses of DNA, protein and glycosaminoglycans (GAG) of cultured vascular smooth muscle cells (SMC) were studied. SMC were isolated from the thoracic aorta of male Wistar rats. The syntheses of DNA, protein and GAG of SMC were determined by incorporations of [3H]thymidine, [3H]leucine and [35S]sulfuric acid, respectively. Insulin at a concentration of 10(-6) M stimulated DNA synthesis 4 fold compared to control. Beraprost sodium suppressed the insulin-stimulated DNA synthesis dose-dependently at concentrations greater than 10(-7) M and suppressed it by 68% at 10(-5) M. Platelet derived growth factor (PDGF) at a concentration of 20 ng/ml stimulated DNA synthesis 6 fold compared to control. Beraprost sodium suppressed the PDGF-stimulated DNA synthesis dose-dependently at concentrations greater than 10(-7) M and suppressed it by 51% at 10(-5) M. Beraprost sodium suppressed GAG synthesis dose-dependently at concentrations greater than 10(-7) M and suppressed it by 49% at 10(-5) M. However, beraprost sodium at concentrations up to 10(-5) M did not affect protein synthesis. These results indicate that beraprost sodium suppressed the proliferation and GAG synthesis of SMC but did not affect hypertrophy. Beraprost sodium may be a potent antiarteriosclerotic agent through suppression of hyperplasia of SMC and modification of matrix protein.

Production and characterization of monoclonal antibodies to porcine group C rotaviruses cross-reactive with group A rotaviruses

Five monoclonal antibodies (MAbs) to porcine group (gp) C rotaviruses (Cowden and Ah strains) reactive with both gp A and C rotaviruses in cell culture immunofluorescence (CCIF) tests were produced and characterized. These MAbs reacted with three strains of gp A and two strains of gp C rotaviruses in a CCIF test and were classified into two groups based on their CCIF titers. The MAbs also reacted to various degrees with cell-culture-propagated porcine gp C rotavirus (Cowden) and bovine gp A rotavirus (NCDV) in an enzyme-linked immunosorbent assay by using the MAbs as capture antibodies. Fecal samples containing human, bovine, and porcine strains of gp A and C rotaviruses were positive when tested using one of the MAbs in this assay. The MAbs recognized VP6 of gp A rotavirus and the VP6 counterpart (41-kDa protein) of gp C rotavirus in a Western blot assay. Results of competitive binding assays on four MAbs indicated that gp A and gp C rotaviruses share three overlapping epitopes within a single antigenic domain. These results suggest that gp A and C rotaviruses share a common antigen located on the VP6 protein, which is recognized by certain MAbs in various serologic assays.

Evidence of serologic diversity within group C rotaviruses

The Cowden strain of porcine group C rotavirus and the Shintoku strain of bovine group C rotavirus were classified as different serotypes by two-way cross-neutralization tests. Two neutralization patterns against the Cowden and Shintoku strains were observed when hyperimmune or convalescent-phase antisera to three noncultivatable porcine group C rotaviruses and a human group C rotavirus were used in one-way cross-neutralization tests. Antisera to two porcine group C rotaviruses and the human group C rotavirus neutralized the Cowden strain at high titers but did not neutralize the Shintoku strain, suggesting that these three strains are serotypically related to the Cowden strain. The remaining antisera to a porcine group C rotavirus (HF strain) reacted with the Cowden and Shintoku group C rotaviruses in cell culture immunofluorescence tests but did not neutralize either virus in one-way cross-neutralization, suggesting that the HF strain belongs to a third serotype. However, confirmation of these findings requires additional analysis by two-way cross-neutralization. Our findings support the existence of at least two distinct serotypes of group C rotaviruses, and possibly a third, among animals and humans. The serotypic similarity observed between the Cowden strain and a human group C rotavirus suggests that the cultivatable Cowden strain and antiserum to this virus may provide important reagents for the diagnosis of group C rotaviruses in humans.

Cardiac cycle length variability in ponies at rest and during exercise

We evaluated cardiac cycle length variability in ponies at rest and during strenuous exercise with and without premedication with atropine. In the absence of premedication, cardiac cycle length at rest was 1,112 +/- 53 ms, the individual cardiac cycle length standard deviation (SDCL) was 75 +/- 23 ms, and the individual cycle length coefficient of variation (CVCL) was 6.32 +/- 1.62. Exercise significantly decreased (P < 0.05) all three indexes (290 +/- 9 ms, 5 +/- 1 ms, and 1.65 +/- 0.20, respectively). Atropine premedication significantly reduced resting cardiac cycle length (685 +/- 46 ms), SDCL (10 +/- 2 ms), and CVCL (1.45 +/- 0.19) compared with nonpremedicated values. Cardiac cycle length was significantly decreased by exercise after atropine premedication, but no statistically significant changes occurred in SDCL or CVCL. Thus, although considerable cardiac cycle length variability exists in nonpremedicated ponies at rest, it is nearly completely abolished by strenuous exercise. The absence of significant differences between the indexes of variability during exercise without premedication, at rest after atropine, and during exercise after atropine indicates that cardiac cycle length variability in the pony is mediated primarily through activity of the parasympathetic system.

Nucleotide sequence of gene 5 encoding the inner capsid protein (VP6) of bovine group C rotavirus: comparison with corresponding genes of group C, A, and B rotaviruses

To further study the molecular characteristics of group (gp) C rotaviruses, we produced, cloned, and sequenced cDNA to gene 5 of the Shintoku strain of bovine gp C rotavirus. The resulting clone was specific for gene 5 and was genetically related to the human and porcine gp C rotaviruses, as demonstrated by Northern blot hybridization analysis. The Shintoku gene 5 is 1352 nucleotides in length and has one open reading frame encoding a polypeptide of 395 amino acids with a predicted molecular mass of 44.5 kDa. Comparative sequence analysis indicated that: (i) the Shintoku gene 5 protein shared 88.4 to 90.6% homology with the VP6 of the human (Bristol and 88-220) and porcine (Cowden) strains of gp C rotaviruses, but only low homology with the VP6 of bovine gp A (RF) and human gp B (ADRV) rotaviruses (41.3 and 16.3%, respectively); (ii) the predicted secondary structure was highly conserved among the gene 5 proteins of the bovine, porcine, and human gp C rotaviruses; and (iii) seven highly conserved regions were identified for the first time in the deduced primary amino acid sequences of gene 5 of gp C and gene 6 of gp A rotaviruses. However, only three of these highly conserved areas were present in the regions of VP6, where the secondary structure was predicted to be similar for the rotavirus strains examined. These three regions may contribute to common epitopes between the two groups of rotaviruses. Our results, in comparison with data for other rotaviruses, indicate that gene 5 of the bovine gp C rotavirus codes for the major inner capsid protein (VP6).

ATP-sensitive K+ conductance in pancreatic zymogen granules: block by glyburide and activation by diazoxide

The properties of transporters (or channels) for monovalent cations in the membrane of isolated pancreatic zymogen granules were characterized with an assay measuring bulk cation influx driven by a proton diffusion potential. The proton diffusion potential was generated by suspending granules in an isotonic monovalent cation/acetate solution and increasing the proton conductance of the membrane with a protonophore. Monovalent cation conductance had the sequence Rb+ > K+ > NA+ > Cs+ > LI+ > N-methyl glucamine+. The conductance could be inhibited by Ca2+, Mg2+, Ba2+, and pharmacological agents such as quinine, quinidine, glyburide and tolbutamide, but not by 5 mM tetra-ethyl ammonium or 5 mM 4-aminopyridine, when applied to the cytosolic surface of the granule membrane. Over 50% of K+ conductance could be inhibited by millimolar concentrations of ATP or MgATP. The inhibition by MgATP, but not by ATP itself, was reversed by the K+ channel opener diazoxide. The inhibitory effect is probably by a noncovalent interaction since it could be mimicked by nonhydrolyzable analogs of ATP and by ADP. The reversal of MgATP inhibition by diazoxide may be mediated by phosphorylation since it was not affected by dilution, and was blocked by the protein kinase inhibitor H7. The properties of the K+ conductance of pancreatic zymogen granule membranes are similar to those of ATP-sensitive K+ channels found in the plasma membrane of insulin-secreting islet cells, neurons, muscle, and renal cells.

Reversal of doxorubicin resistance by tetrandrine in Chinese hamster ovary cell line

Tetrandrine (Tet) 0.5 microgram.ml-1 and 1 microgram.ml-1 potentiated 2.88- and 4.3-fold growth-inhibitory effects of doxorubicin (Dox) in Chinese hamster ovary cell line (CHO), respectively, while Tet 1 microgram.ml-1 and 2.5 micrograms.ml-1 potentiated 7.3- and 8.4-fold in its resistant cell line (CHO/Dox), respectively. The colony-forming efficiencies were reduced in CHO and CHO/Dox when the cells were treated with noncytotoxic doses of Tet 2.5 micrograms.ml-1 and 5 micrograms.ml-1 in combination with different concentration of Dox. Increase in accumulation of Dox in CHO/Dox cells was shown by fluorometry. The result indicated that Tet reversed the resistance to Dox in CHO/Dox cells.

[Effects of imipramine on isolated rabbit basilar artery]

Imipramine (Imi) inhibited the contractile response to BAY k 8644 (IC50 = 2.39 +/- 0.33 mumol.L-1), KCl (IC50 = 1.00 +/- 0.09 mumol.L-1), in rabbit basilar artery rings. Imi was more effective in suppressing the contractile response evoked by KCl, CaCl2, and 5-HT in basilar artery rings than in mesenteric artery rings. The effect of Imi was the same as that of diltiazem (Dil). There was no difference between the inhibitory response of Imi on contraction induced by KCl in basilar artery rings with or without endothelium. The results suggest that Imi may block the calcium channel and inhibit the rabbit basilar artery selectively, and the effect is endothelium-independent.

Adaptation of fibers in fast-twitch muscles of rats to spaceflight and hindlimb suspension

The adaptation of single fibers in medial gastrocnemius (MG), a fast-twitch extensor, and tibialis anterior (TA), a fast-twitch flexor, was studied after 14 days of spaceflight (COSMOS 2044) or hindlimb suspension. Cross-sectional area (CSA) and succinate dehydrogenase (SDH), alpha-glycerophosphate dehydrogenase (GPD), and myofibrillar adenosinetriphosphatase (ATPase) activities were determined in fibers identified in frozen serial cross sections. Fibers were categorized as light, dark, or intermediate on the basis of myosin ATPase staining and alkaline preincubation and immunohistochemically as reacting with slow, fast, or both slow and fast myosin heavy chain monoclonal antibodies. Because there was a close relationship between these two means of categorizing fibers, all fibers were categorized on the basis of the immunohistochemical reaction. The percentage of slow- and fast-twitch fibers of the MG and TA were unchanged in either group. Mean fiber size of all fibers, irrespective of type, was unaffected in either muscle after flight or suspension. The fibers that expressed both fast and slow myosin heavy chains were smaller than control in the MG of both experimental groups. Compared with control, the SDH and total SDH activities in the MG were significantly less in suspended rats, with the fast-twitch fibers showing the largest difference. The ATPase activity in the MG was higher in flight than in control or suspended rats. There were no significant effects of flight on fibers of the TA. In contrast, the TA in suspended rats had higher GPD activities than either control or flight rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Ventral horn cell responses to spaceflight and hindlimb suspension

Spaceflight or hindlimb suspension results in a loss of mass and alterations of the metabolic and contractile protein profiles of skeletal muscles toward that resembling faster muscles. Given the influence of motoneurons on muscle properties, ventral horn cells of the lumbosacral enlargement of the spinal cord were studied to determine whether similar adaptations were present. Three groups of rats (5 per group) were studied: control, 14-day spaceflight, and 14-day hindlimb suspension. Spinal cords were quick-frozen, and the succinate dehydrogenase (SDH) activity and cross-sectional area of the soma of ventral horn cells were measured using a computer-enhanced image-processing system. Briefly, the optical density for SDH activity was determined after 8 min of incubation in a medium that gave a steady-state enzymatic reaction. Soma sizes were determined in cells with a visible nucleus. Although there were no significant differences among the three groups in mean cross-sectional area and SDH activity, the population distributions of both variables shifted significantly. In the flight rats, there was a shift toward smaller cells. Compared with control, the population distribution of SDH activities in the flight rats shifted toward higher activities, whereas the distribution shifted toward lower activities in the suspended rats. When considering the interactive effects within individual cells, there was a higher percentage of small cells with high SDH activities in the flight than in the control or suspended rats. These contrasting effects of spaceflight and hindlimb suspension suggest that the changes observed in ventral horn cells were due to factors other than simply the absence of weight support.

Rat soleus muscle fiber responses to 14 days of spaceflight and hindlimb suspension

Morphological and enzymatic responses in fibers expressing fast, slow, or both types of myosin heavy chain (MHC) were studied in rats after 14 days of spaceflight (COSMOS 2044) or hindlimb suspension. Although the percentage of slow-twitch fibers was unchanged, a higher percentage of fibers that expressed both slow and fast MHC was observed in flight and suspended rats than in synchronous ground-based controls. The soleus was 25 and 34% smaller than control after 14 days of flight and suspension, with the reduction in fiber cross-sectional area (CSA) being greater in slow- than in fast-twitch fibers in both experimental groups. The activities of succinate dehydrogenase (SDH) and alpha-glycerophosphate dehydrogenase (GPD) were not significantly affected by flight or suspension. The total SDH activity (i.e., SDH activity x CSA) decreased significantly in the slow-twitch fibers of the flight and the fast-twitch fibers of the suspended rats, in large part due to fiber atrophy. A shift in MHC expression in 14 and 9% of the fibers in flight and suspended rats occurred without a change in myosin adenosinetriphosphatase activity. The SDH and GPD activities of the fibers that expressed both slow and fast MHC were slightly higher than the slow-twitch fibers and slightly lower than the fast-twitch fibers. These data indicate that events were initiated within 14 days of spaceflight or suspension that began to reconfigure the protein profiles of 9-14% of the slow-twitch fibers from typical slow-twitch toward those of fast-twitch fibers, while all fibers were dramatically losing total protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of group C rotavirus antigens and antibodies in animals and humans by enzyme-linked immunosorbent assays

Enzyme-linked immunosorbent assays (ELISAs) were developed to detect group (gp) C rotavirus antigens and antibodies. Both assays were confirmed to be specific for gp C rotavirus by using serogroup A, B, and C rotaviruses; hyperimmune antisera to these serogroups of rotaviruses; and paired serum specimens from animals infected with gp C rotaviruses. The ELISA for antigen detection reacted not only with porcine gp C rotaviruses but also with human and bovine gp C rotaviruses. Following experimental challenge of gnotobiotic pigs with porcine gp C rotavirus, the virus was found by ELISA in all diarrheic feces. A high prevalence of antibodies to gp C rotaviruses was detected in sera from adult pigs (93 to 97%) and cattle (47 to 56%) in the United States and Japan. However, no antibody to gp C rotavirus was detected in the sera (n = 20) of adult horses in the United States. In human sera from Hokkaido, Japan, 3% of children and 13% of adults possessed antibody to gp C rotaviruses. These results suggest that the ELISA that we developed may be useful for surveying gp C rotavirus infections in animals and humans. On the basis of serology, gp C rotavirus infections are common in pigs and cattle in the United States and Japan, but they occur at lower levels in humans from the Hokkaido area of Japan.

[Role of catecholamines in action of nicotine on slow action potentials in guinea pig papillary muscles]

The action potential duration (APD) of histamine-induced slow action potentials (SAP) and force of contraction (FC) were potentiated by nicotine (0.6-1.0 mmol.L-1) on guinea pig papillary muscles in a concentration-dependent manner. In the presence of atropine, nicotine concentration dependently suppressed the action potential amplitude (APA), APD, the maximal upstroke velocity (Vmax), and FC in catecholamine-depleted (reserpine 2.5 mg.kg-1 ip, 15 h prior to the experiment) muscles. Nicotine (0.6 mmol.L-1) itself induced SAP and enhanced FC. These 2 effects were antagonized by verapamil. A linear relationship existed between APA of nicotine-induced SAP and 1g [Ca2+]0 with a slope of 23.2 mV for a 10-fold change in [Ca2+]0. These results suggested that the effects of nicotine on enhancing Isi were mediated by the release of catecholamines in myocardium.

[Clinical analysis of 60 cases of pregnancy with thrombocytopenia]

Sixty cases of pregnancy with thrombocytopenia were analyzed. Bleeding syndrome was found in 36 patients during pregnancy, with 7 cases suffering from massive hemorrhage during delivery and a postpartum hemorrhage rate of 11.7%. There was a negative correlation between the platelet level and the amount of bleeding during gestation and delivery. We suggest that cortico steroid is necessary with a platelet count less than 50 x 10(9)/L in the middle or late trimester of pregnancy to reduce the bleeding tendency during delivery, as well as the incidence of thrombocytopenia in the newborn infant use of excessive platelet transfusion is not encouraged, since it implicates an increase in antibody-induction (PAIG) and probability of C type hepatitis in the recipient. Platelet transfusion should be reserved only for the treatment of serious hemorrhage. There were 53 newborn infants, 7 of whom (13.2%) suffered from thrombocytopenia, with a mortality of 1.9% (7/53) during the perinatal.

The Aeromonas hydrophila exeE gene, required both for protein secretion and normal outer membrane biogenesis, is a member of a general secretion pathway

The Aeromonas hydrophila Tn5-751 insertion mutant L1.97 is unable to secrete extracellular proteins, and is fragile because of defective assembly of its outer membrane. A KpnI 4.1 kb fragment, which complements this mutant when supplied with an exogenous promoter, was isolated and sequenced. It contains two complete genes, exeE and exeF, plus fragments of two others and may form part of an operon. The exeE and exeF open reading frames encode 501-residue M(r) 55,882 and 388-residue M(r) 43,431 proteins, respectively. These genes were expressed in vitro and their initiation codons verified by deletion analysis. Tn5-751 had inserted near the centre of the exeE gene in the L1.97 strain. Subclones of the KpnI 4.1 kb fragment which contained only the exeE gene fully complemented the mutation, indicating that its function is required both for extracellular secretion and outer membrane assembly. ExeE and ExeF are highly similar to other proteins which have been shown to be involved in extracellular secretion, suggesting that an additional export apparatus beyond that required for inner membrane translocation may be part of the physiology of many Gram-negative bacteria.

[Effects of trihexyphenidyl on slow action potentials in guinea pig papillary muscles]

Effects of trihexyphenidyl (THP) were examined on the slow action potentials (SAP) induced by isoproterenol (Iso), histamine (His), Bay k 8644 or tetrodotoxin (TTX), in guinea pig papillary muscles. THP 10, 50, and 100 mumol.L-1 depressed the maximal upstroke velocity (Vmax) and the action potential amplitude (APA) of SAP. These effects were reversed partially by the elevation of the concentration of calcium from 2.0 to 5.6 mmol.L-1. The results suggest that THP can inhibit calcium inflow in myocardium.

DNA content and its relationship with pathology and prognosis of colorectal carcinoma

The DNA content of 181 colorectal cancers was investigated by flow cytometry on paraffin-embedded specimen. The relationship of flow cytometric DNA patterns of colorectal cancer to Dukes's stage, histological type and grade, tumor size and patient's prognosis were analysed. The DNA aneuploid carcinomas were found in 53.04% of the patients (hypodiploid 22.10%, hyperdiploid 20.99%, polyploid 9.94%). Diploidy was found in 46.96% of the patients with colorectal cancer. The proportions of aneuploidy were significantly lower in the patients with Dukes' stage A (25.00%) and B (47.14%) than those with Dukes' stage C (64.71%) and D (68.42%). Aneuploid frequency was higher in the patients with poorly differentiated adenocarcinoma (84.62%), mucinous adenocarcinoma (62.50%) and tubular adenocarcinoma (52.75%) than those with villous adenocarcinoma (22.86%). The proportion of aneuploidy was significantly higher in the patients with poorly differentiated tumor (71.79%) than in those with moderately (50.00%) and well differentiated tumors (44.83%). Five-year survival rate of the patients with DNA aneuploid tumors was 33.80% compared with 66.67% of those with diploid tumors. Analysis of Cox regression revealed that DNA ploidy and Dukes' stage significantly influenced the patient's prognosis. It is suggested that DNA ploidy might be an important prognostic factor in colorectal cancer.

Enzyme and size profiles in chronically inactive cat soleus muscle fibers

Spinal isolation (SI), i.e., the isolation of the lumbar spinal cord via a rostral and a caudal cord transection and bilateral dorsal rhizotomy, was used to determine the effects of chronic (6 months) inactivity on the size and metabolic properties of fibers in the cat soleus. Fibers were classified as dark or light, based on their staining reactions to myosin ATPase, alkaline preincubation, and immunohistochemically as expressing fast and/or slow myosin heavy chains (MHC). Succinate dehydrogenase (SDH) and alpha-glycerophosphate dehydrogenase (GPD) activities were assessed histochemically. Following SI, both the light and the dark ATPase fibers in the SI cats were significantly smaller than the light ATPase fibers in the controls. Normally 100% of the fibers were light ATPase and reacted exclusively with the slow antibody. After SI, approximately 45% of the fibers were dark ATPase fibers, many reacting with both fast and slow MHC antibodies. The total amount and concentration of GPD were higher in the light and dark ATPase fibers in SI compared with light ATPase fibers in controls. In contrast, although the total amount of SDH per fiber was decreased, reflecting the decrease in fiber size, the mean SDH concentration per fiber was unchanged following SI. These data indicate that there is a close coordination in the regulation of GPD activity and the type of myosin. SDH activity, on the other hand, appears to be resistant to decreased levels of activity and unloading, i.e., there seems to be a minimum level of oxidative potential in the soleus that is independent of activity level. Fiber sizes, however, are very sensitive to less-than-normal amounts of neuromuscular activity and/or loading.

The therapeutic and biological effects of total lymph node irradiation and autologous bone marrow infusion on malignant lymphoma patients

Forty patients with malignant lymphoma were treated by 60Co total lymphoid irradiation (TLI): 21 cases received 6 Gy and 19 received 8 Gy. Ten also received autologous bone marrow infusion (ABMI). Acute radiation damage with digestive tract reaction and hemopoietic and immunological depression was observed. Bone marrow was depressed. WBC and platelets decreased rapidly. Lymphocytes showed quantitative and qualitative changes even at the early stage. All these symptoms subsided within 40 days. TLI accompanied by irradiation of the tumor site could result in effective control. The 1-, 3-, and 5-year survival rates of malignant lymphoma patients were 30/40 (75%), 14/24 (58%) and 4/12 (33%), respectively, while in those with Hodgkin's disease alone, the 1- and 3-year survival rates were 10/13 (76%) and 5/7 (71.4%), respectively. ABMI hastened hemopoietic reconstitution, which recovered relatively quickly after TLI.

Comparison of human and porcine group C rotaviruses by northern blot hybridization analysis

The genetic relationship between human and porcine Gp C rotaviruses and between Gp C and Gp A or B rotaviruses was examined by Northern blot hybridization. Cross-hybridization studies using radiolabeled ssRNA transcript probes demonstrated that the human and porcine Gp C rotaviruses shared a high degree of nucleotide sequence homology in most of the eleven gene segments; the greatest sequence divergence was observed in gene 7. Neither the human nor the porcine Gp C probe hybridized strongly with gene segments from Gp A reference strains or a Gp B bovine rotavirus. These data indicate that genetically, porcine and human Gp C rotaviruses are closely related, whereas they are quite distinct from Gp A or B suggesting that porcine and human Gp C rotaviruses may have evolved from a common ancestral source.

Calcium reveals different mechanisms of guanylate cyclase activation by atrial natriuretic factor and ATP in rat lung membranes

CaCl2 inhibited ATP-stimulated guanylate cyclase activity, but had little effect on basal and atrial natriuretic factor-stimulated guanylate cyclase activity in rat lung membranes. LaCl3 had similar effects as CaCl2 on basal and stimulated guanylate cyclase activity. LiCl and other monovalent salts inhibited ATP-stimulated guanylate cyclase activity more than basal enzyme activity. However, atrial natriuretic factor somehow stabilized the enzyme against the inhibitory effect of LiCl. These results suggest that ATP and atrial natriuretic factor activate the enzyme through different mechanisms. Since the effect of calcium on guanylate cyclase activity is different from that of monovalent salts and can be mimicked by lanthanum, it may be mediated by a specific calcium binding site or binding protein.

[Analysis of main transmission factors of hepatitis A]

A case control study (1:2) of 182 pairs of Hepatitis A was carried out in Weng-ling Zhe-jiang during April 1988. The results showed that adjusted odds ratio (aOR) had a dose-response relationship with exposed different food factors.

[The study of Bacillus sphaericus Ts-1 protoplast-plasmid transformation of electroporation]

This report gave the best conditions of Bacillus sphaericus Ts-1 protoplast-plasmid pHV33 electroporation. The highest transformation frequency and transformation efficiency induced by three pulse of 21 KV/cm and 10 microseconds duration applied at an interval of one sec., was 2.44 x 10(2) transformants/micrograms DNA and 3.16 x 10(-6) respectively. The saturated concentration of DNA absorbed by the protoplast was 5 micrograms DNA/10(9) cells/ml. By means of this method, pJB417, a recombinant mosquito larvicide clone, was introduced into B. subtilis 168M and B. sphaericus Ts-1. The transformants of B. subtilis 168M with biocide activity were obtained, but the toxicity of B. sphaericus Ts-1 was not increased.

Nonlinear algorithm for identification of a fiducial marker for various cardiac events

We report on a nonlinear algorithm which identifies R-wave peaks on the surface electrocardiogram, consistent reference points on the left ventricular pressure waveform and the initiation of the QRS complex on the epicardial electrogram. The algorithm has been used to evaluate data from horses, ponies, dogs and humans at rest and during exercise. It permits rapid, accurate evaluation of data on a beat-by-beat basis even with noisy signals and varying waveform configurations. The algorithm facilitates the acquisition of detailed information previously difficult or impossible to obtain by more conventional methods of analysis.

Expression of a fast fiber enzyme profile in the cat soleus after spinalization

This study was designed to determine the effects of reduced neuromuscular activity on the expression of proteins associated with contractile and metabolic functions and the size of single muscle fibers in the cat soleus. Adult cats were spinalized (Sp) at T12-T13 and maintained in a healthy condition for 6 months. Some of the cats were trained to weight-support (Sp-WS) for 30 minutes per day beginning one month posttransection. Cross-sectional area (CSA), succinate dehydrogenase (SDH), alpha-glycerophosphate dehydrogenase (GPD), and myofibrillar adenosine triphosphatase (ATPase) activities were determined in a population of single fibers identified in frozen serial cross-sections. Each fiber was categorized as either light or dark based on its staining density for qualitative myosin ATPase, alkaline preincubation (pH 8.75). The Sp (45%) and Sp-WS (31%) groups had significantly higher percentages of dark ATPase fibers than control (less than 1%). All dark ATPase fibers were shown to react positively for a fast myosin heavy chain monoclonal antibody, while some of these fibers showed a reaction to both fast and slow myosin heavy chain antibodies. Overall mean fiber CSA were significantly smaller (approximately 25%) than control in both Sp groups. In the Sp-WS, but not the Sp cats, the dark fibers were larger than the light fibers (P less than 0.05), suggesting a preferential effect of postural training on the ATPase converted fibers. There were no significant differences among the three groups in any of the mean enzyme activities for either ATPase type fiber. However, there was a general tendency for the Sp cats to have elevated GPD and ATP activities per muscle; this appeared to be directly related to the percentage of fibers staining darkly for myosin ATPase. These data indicate that 6 months after spinalization some of the fibers of the slow muscle developed fast myosin staining patterns and oxidative and glycolytic enzyme profiles that are normally exhibited in fast fatigue-resistant motor units. Periods of daily weight-support appear to ameliorate some of these adaptations to spinalization. Further, the observation that SDH activities are maintained at control values in spinalized adult cats as well as in spinalized kittens (unpublished observations) suggest that, at least in the soleus, skeletal muscle fibers can maintain their oxidative potential even though there is a marked reduction in neuromuscular activity for 6 months.

Structural requirements of ATP for activation of basal and atrial natriuretic factor-stimulated guanylate cyclase in rat lung membranes

ATP has been reported to increase basal and atrial natriuretic factor (ANF)-stimulated guanylate cyclase activity. The structural features of ATP involved in the activation of guanylate cyclase were examined by employing a variety of ATP analogs with modification either at the phosphate chain or at the ribose moiety. Among the natural adenine nucleotides, ATP and ADP were able to increase both basal and ANF-stimulated guanylate cyclase activities in rat lung membranes. AMP had no effect. ATP was more effective than AMPPCP (the non-hydrolyzable analog of ATP), and ADP was more effective than ADP beta S and AMPCP (the hydrolysis-resistant analogs of ADP) to increase basal and ANF-stimulated guanylate cyclase activities. Removal of the oxygen atom from the ribose moiety of ATP or ADP significantly reduced their potency. Thus, the length of the phosphate chain and the hydroxyl groups at the ribose moiety are both determinants for nucleotide mediated guanylate cyclase activation.

Enzymatic plasticity of medial gastrocnemius fibers in the adult chronic spinal cat

The metabolic plasticity of single fibers in adult cat medial gastrocnemius (MG) 6 mo after complete spinal cord transection (Sp) at T12-T13 was studied. Some Sp cats were trained to weight support (Sp-WS) 30 min/day beginning 1 mo posttransection. Cross-sectional area, succinate dehydrogenase (SDH), alpha-glycerophosphate dehydrogenase (GPD), and myofibrillar adenosinetriphosphatase (ATPase) activities were determined in fibers identified in frozen serial sections. Fibers were categorized as light or dark based on myosin ATPase staining, alkaline preincubation. The percentage of dark ATPase fibers was higher in Sp and Sp-WS (approximately 85%) than in control (approximately 60%). All dark ATPase fibers reacted positively to a fast myosin heavy chain monoclonal antibody. In both spinal groups, a higher percentage of dark ATPase fibers reacted to both fast and slow myosin heavy chain antibodies than in controls. Neither Sp nor Sp-WS cats showed fiber atrophy. Compared with control, SDH activity was decreased in both fiber types of Sp cats. Daily weight-support training ameliorated this adaptation. There were no differences among the three groups in mean GPD and ATPase activities for either fiber type. There was a slight tendency, however, for spinal cats to have higher GPD and ATPase activities (independent of type) than control, probably reflecting the larger proportion of dark ATPase fibers in these cats. These observations indicate that 6 mo after spinalization in adult cats, some of the fibers of a fast muscle became "faster" and developed oxidative and glycolytic enzyme profiles that normally are exhibited in fast fatigable motor units.(ABSTRACT TRUNCATED AT 250 WORDS)

[Studies and comparisons on chemical components of essential oils from Clematis hexapetala Pall. and Inula nervosa Wall]

Chemical components of the essential oils from clematis hexapetala and Inula nervosa were analyzed by using GC-MS-DS. The result shows that the major components of the essential oil from Inula nervosa are thymol and thymol isobutyrate, while the major components of the essential oil from Clematis hexapetala are palmitic acid and 3-hydroxy-4-methoxyl benzaldehyde.

Caged ATP potentiates guanylate cyclase activity stimulated by atrial natriuretic factor in rat lung membranes

ATP increases both basal and atrial natriuretic factor (ANF)-stimulated guanylate cyclase activities. The present studies were designed to compare the effect of adenosine-5'-triphosphate, P3-1-(2-nitrophenyl)-ethyl ester (caged ATP), a photolabile derivative of ATP, with ATP. Caged ATP increases both basal and ANF-stimulated enzyme activities in a concentration-dependent manner, but is more potent than ATP. The effect of caged ATP significantly decreases after it is photo-converted to ATP by UV irradiation. These observations suggest that the caged group introduces a hydrophobic interaction thereby facilitating guanylate cyclase activation.

Characterization of ATP-stimulated guanylate cyclase activation in rat lung membranes

Many of the effects of ANP are mediated through the elevation of cellular cGMP levels by the activation of particulate guanylate cyclase. While the stimulation of this enzyme is receptor-mediated, the molecular mechanism of activation remains unknown. In this study we present evidence that ATP as well as its analogues adenosine-5'-O-(3-thiotriphosphate) (ATP gamma S) and adenylylimidophosphate (AMPPNP) activates guanylate cyclase from rat lung membranes and markedly potentiates the effect of ANP on the enzyme. The order of potency is ATP gamma S greater than ATP greater than AMPPNP. The enzyme activation by adenine nucleotide and ANP together is much more than the sum of the individual activations, suggesting that ATP may be the physiological component essential for the ANP-stimulated guanylate cyclase activation. The ATP gamma S-stimulated guanylate cyclase activity diminishes in the presence of various kinds of detergents, suggesting either that the conformation of an ATP binding site in guanylate cyclase is altered by detergents or that protein-protein interaction may be involved in the activation of guanylate cyclase by ATP. Guanylate cyclase from rat lung membranes is poorly activated by ANP and/or ATP gamma S after removing the cytosolic and weakly membrane-associated proteins or factors by centrifugation. Pre-incubation of the membranes with ATP gamma S retains enzyme activation after membrane washing. These results suggest either that ATP gamma S stabilizes the conformation of nucleotide binding site in guanylate cyclase from denaturation by membrane washing, or that the stimulatory effect of ATP on guanylate cyclase activity may be mediated by accessory proteins or non-protein cofactors which are lost during membrane washing, but remain bound to membranes by ATP gamma S pretreatment.

Allogeneic bone marrow transplantation for the treatment of leukemia

Eighteen patients with leukemia have received HLA-identical allogeneic bone marrow transplantation (BMT) at our hospital since 1981. Fifteen of these patients have been living without relapse. for prophylaxis of GVHD, MTX was used in 8 patients, and cyclosporine (CSP) together with MTX in 6 patients, 3 received multiple agents at much smaller dosage, including monoclonal antibody. All patients received intravenous placental gamma-globulin, and 16 received garlic extract. Three patients died. One, who neither received MTX, nor CSP died of hyperacute GVHD, one who did not receive garlic extract died of GMV pneumonia, and the third one died of tuberculosis 18 months after BMT.

Structural and functional analysis of murine skeletal muscle after castration

A previous histochemical and morphometric study demonstrated that castration caused a significant decrease in myofiber and muscle size in the extensor digitorum longus (EDL) muscles of male ReJ 129 mice. The objective of the present study was to examine the effects of castration on the morphology and physiology of the EDL. Muscle wet weight was significantly decreased in the castrated group. The morphological survey demonstrated a significant degree of degeneration in the EDL muscles from castrated animals, consisting of disruption of normal myofilament arrangement and necrosis, invasion of active macrophages, and atrophic myofibers. These findings were significantly correlated with the decrease in peak tension observed in the castrated groups. No significant difference was detected in the time to peak tension and half-relaxation time in the castrated groups compared with the control. Thus, alterations of the morphological integrity and myofiber size of skeletal muscle affect muscle strength in castrated animals.

A system for deriving revertants of oncogene-transformed human cells

We have previously shown that some transformed derivatives of the human osteosarcoma-derived cell line HOS are killed by treatment with 1 microM ouabain at pH 8.2, whereas their nontransformed counterparts are relatively unharmed by the same conditions. HOS cells transformed by v-Ki-ras and RAS, v-fms, or MET are susceptible to 1 microM ouabain while those transformed by v-fes are not. Here we describe the adaptation of this differentially cytotoxic effect as a method to enrich for cells which revert to a nontransformed phenotype. We have optimized parameters which increase the differential cytotoxicity, including pH and potassium concentration during and subsequent to ouabain treatment. The efficiency of this procedure was tested in mixed cell experiments where model populations were constructed consisting of HOS cells mixed with an excess of v-Ki-ras-transformed HOS cells. Two successive OAK treatments (ouabain/alkaline/K+-free) were sufficient to recover nontransformed cells free of ras-transformants as indicated by genetic markers and morphology. This HOS/ouabain system is currently being used to derive revertants of ras-transformed human cells and could facilitate the isolation of genes interacting in the pathways by which these cells are transformed.

An analysis on the equivalence of the eye to a system with aberration

Computed transfer functions for epsilon = 0.60 and 0.75 annular pupils of 2.67 mm o.d. show that absorption of the average spherical aberration of the eye is still incomplete but if the eye is so designed as to adjust its focal plane in order to achieve a best Strehl ratio, it would show a transfer function approaching that of a diffraction limited system, i.e. the optical defect of the eye is overcompensated. However, it is argued that a varying amount of focusing adjustment of the eye is needed in order to account for the transfer function of the eye of different pupil sizes, though not always to the extent of achieving a best Strehl ratio. Such a property of the eye is referred to variously as the antidefocusing, deblurring or contrast constancy phenomenon and, when operationally defined, this is equivalent to saying that the eye has a greater depth of focus than that defined for a physical system based upon a fixed demodulation criterion. The significance of the physiological depth of the eye is discussed.