Effects of the new thromboxane A2 antagonist vapiprost on isolated canine blood vessels

Effects of the new thromboxane A2 antagonist vapiprost (SN-309, GR-32191B, CAS 85505-64-2) on isolated canine blood vessels were investigated. U46619 ((15S)-hydroxy-11a, 9a-(epoxymethano) prosta-5Z, 13E-dienoic acid) 10(-10)-10(-6) mol/l, a thromboxane A2 analogue, produced concentration-dependent contractions of oblong or ring preparations isolated from basilar, coronary, mesenteric and femoral arteries. Vapiprost 10(-8) and 10(-7) mol/l significantly and concentration-dependently shifted the concentration-contraction curves for U46619 of these arteries to the right. The pA2 values were 8.80 +/- 0.09 in basilar arteries, 8.67 +/- 0.12 in coronary arteries, 8.86 +/- 0.05 in mesenteric arteries and 9.01 +/- 0.07 in femoral arteries. On the other hand, oblong or ring preparations of basilar, coronary, mesenteric and femoral arteries showed sustained contractile responses to KCl 3 x 10(-2) mol/l, U46619 10(-7) mol/l or prostaglandin (PG) F2 alpha 10(-5) mol/l. Norepinephrine (NE) 3 x 10(-5) mol/l also produced sustained contractions in mesenteric and femoral arterial preparations, but not in basilar and coronary arterial preparations. Vapiprost 10(-10)-3 x 10(-6) mol/l relaxed these four arterial preparations constricted with U46619 10(-7) mol/l and PGF 2 alpha 10(-5) mol/l in a concentration-dependent fashion, but hardly affected them constricted with KCl 3 x 10(-2) mol/l. NE 3 x 10(-5) mol/l-induced contractures of mesenteric and femoral arterial preparations were not influenced by any concentrations of vapiprost. Results indicate that vapiprost has an antagonistic action on a so-called TP-receptor and/or a vasoconstrictive prostaglandin(s)-receptor and thus produces vasorelaxation.

Effects of a new antiarrhythmic drug, SD-3212, on canine ventricular arrhythmia models

The antiarrhythmic effects of a new antiarrhythmic agent, SD-3212, (-)-(S)-3,4-Dihydro-2-[5-methoxy-2-[3-[N-methyl-N-[2-[(3,4- methylene dioxy)phenoxy]ethyl]amino]propoxy]phenyl]-4-methyl-3-oxo-2H-1, 4-benzothiazine hydrogen fumarate, were investigated using canine models of ventricular arrhythmias, i.e. spontaneously occurring digitalis-, two-stage coronary ligation- and adrenaline-induced arrhythmias. SD-3212 suppressed adrenaline-induced arrhythmia and showed some antiarrhythmic effect on digitalis- and 48 hr coronary ligation-arrhythmias. These results indicate that SD-3212 has antiarrhythmic effects common among class IV antiarrhythmic drugs and also has additional efficacy common among class I antiarrhythmic drugs, thus when considering the level of experimental arrhythmias it somewhat resembles propafenone. It may therefore become a clinically useful antiarrhythmic drug among typical class I or class IV antiarrhythmic drugs.

Fine structure of the parotid gland in the crest-tailed marsupial-rat (Dasyuroides byrnei)

The parotid gland of Dasyuroides byrnei was examined by light microscopy, and transmission and scanning electron microscopy. The acini were composed predominantly of seromucous cells with a few mucous cells. The seromucous cells were light or dark cells containing acidophilic spherical granules of moderate to high electron density and had well-developed cytoplasmic organelles-ordinary mitochondria and large mitochondria with tubular cristae, RER with vesicular or tubular elements, and Golgi apparatus with lamellae, vesicles and vacuoles. The mucous cells had basophilic amorphous granules of low electron density, like those of ordinary mucous cells. The intercalated ducts were composed of simple cuboidal light cells having a few electron-dense granules. The striated ducts consisted of tall columnar light cells containing numerous vesicles and mitochondria with tubular cristae, the same as found in acinar seromucous cells.

A POU-domain gene of zebrafish, ZFPOU1, specifically expressed in the developing neural tissues

We have isolated a POU domain-containing cDNA (ZFPOU1) from a cDNA library of zebrafish (Brachydanio rerio). The ZFPOU1 cDNA contained an open reading frame encoding a 425 amino acid peptide. The conserved POU domain was located near the carboxy terminus. The deduced amino acid sequence of the reading frame was most similar to that of the mouse class III POU-domain gene, Brain-1. Northern blot analysis revealed that the ZFPOU1 transcripts first appeared at the early neurula stage of embryogenesis and transiently increased thereafter. A significant level of expression, however, was not found in adult tissues except in the brain. In situ hybridization analysis demonstrated that the ZFPOU1 transcripts were localized in the neural tissues of embryos, but not in mesodermal, endodermal or ectodermal tissues. In adult zebrafish, the ZFPOU1 transcripts were detected in the restricted regions of the brain. Spatial and temporal expression patterns suggest that ZFPOU1 has distinct roles in the early neural development of zebrafish.

Retention fluids of chronic sinusitis induce neutrophil adherence to microvascular endothelial cells

The adherence of circulating leukocytes to the vascular endothelium is a critical step in the emigration of leukocytes through blood vessel walls to inflammatory lesions. The influence of nasal secretions on the adherence of neutrophils to the vascular endothelium was investigated using monolayers of human mucosal microvascular endothelial cells derived from the inferior turbinate. Preincubation of vascular endothelial cells with retention fluids from the maxillary sinus of the patients with chronic sinusitis showed increased neutrophil adherence. Recombinant IL-1 beta was also tested and found to induce adherence of neutrophils to human mucosal microvascular endothelial cells. However, no adhesive effect was observed with the nasal secretions of nasal allergy. An enzyme-linked immunosorbent assay detected considerable amounts of IL-1 beta in the chronic sinusitis retention fluids, while the amounts of IL-1 alpha and TNF-alpha were very low. The increased adhesion of the neutrophils by the retention fluids of chronic sinusitis was also neutralized by the incubation with anti-IL-1 beta antibody in a dose dependent manner. These findings suggest that IL-1 beta in the paranasal secretion of chronic sinusitis induces the adherence of neutrophils to vascular endothelium and subsequent infiltration of neutrophils in the paranasal sinuses, thus contributing to the persistence of chronic sinusitis.

[Studies of human bone marrow stromal cells--effects of antimetabolites on the growing dynamics of human bone marrow cells and their support of hemopoietic cells]

The effects of antimetabolites on the growing dynamics of human bone marrow stromal cells and their support of hemopoietic cells were tested by using a modified version of Dexter's culture system. Cytosine arabinoside (ara-C) was found to suppress neither the growing dynamics nor the supportability. On the other hand, methotrexate (MTX) suppressed the supportiveness, even though it hardly suppressed the growing dynamics. The recognition of injury to marrow cells could be of potential importance in cancer chemotherapy. Our in vitro evidence may provide clinical insights for cancer chemotherapy including prolonged marrow suppression or pretreatment of bone marrow transplantation.

[A case report of replacement of the extracardiac conduit for tetralogy of Fallot: reconstruction with autogenous tissue around the conduit]

Replacement of the valved extracardiac conduit with autogenous tissue was performed on a 13-year-old female. The procedure was based on that reported by Danielson in 1987. She underwent the first operation for tetralogy of Fallot with pulmonary atresia using a valved extracardiac conduit (#16 mm Björk-Shiley valve) 8 years ago. Recently, she complained exertional dyspnea and chest pain. Reoperation was scheduled because of bleeding tendency, somatic growth of the patient, and severe distal anastomotic stenosis of the conduit by right ventriculogram. At operation, the valved conduit was removed under cardiopulmonary bypass, and autogenous connective tissue around the conduit was preserved as the posterior wall of the new conduit. An onlay patch (pericardial monocusp patch) was sutured to form the roof of the new tract. Postoperative catheterization showed no residual stenosis or pressure gradient between the right ventricle and the pulmonary artery. This technique is useful as the replacement of extracardiac conduit because of its simplicity, no necessity of postoperative anti-coagulant therapy, and possibility to make a generous-sized new outflow tract.

Antiarrhythmic and electrophysiological effects of SD-3212, a novel Na+ and Ca++ channel blocker, in anaesthetized dogs with myocardial infarction in comparison with its stereoisomer (SD-3211) and bepridil

Antiarrhythmic and electrophysiological effects of SD-3212, a novel antiarrhythmic agent, which has both Na+ channel and Ca++ channel blocking activities, were compared with those of its (+)-stereoisomer, SD-3211, which has only a Ca++ channel blocking activity, and bepridil, a known Ca++ channel blocker with additional Na+ channel blocking activity, using the two-stage coronary ligation induced arrhythmia (24 h after the ligation of the left anterior descending coronary artery) and 7 day-old myocardial infarcted hearts in anaesthetized dogs. SD-3212 showed a dose-dependent antiarrhythmic effect on the two-stage coronary ligation induced arrhythmia. SD-3212 at a dose of 3 mg/kg reduced the arrhythmic ratio, i.e. ectopic beats per min divided by the sum of ectopic beats and sinus beats per min, significantly from 1 up to 12 min after the administration. Neither bepridil (1-6 mg/kg) nor SD-3211 (1 mg/kg) had an antiarrhythmic effect. SD-3212 (0.3-3 mg/kg) prolonged both the conduction time in the normal myocardium and the delayed potential in the infarcted myocardium in the 7 day-old myocardial infarcted hearts in anaesthetized dogs in a dose-dependent manner. This effect of SD-3212 was shown at coupling intervals of 150-1000 ms increasing with decreasing interval. In this respect, SD-3212 is similar to drugs which show fast recovery of Vmax from use-dependent block such as lidocaine. Bepidril (1-6 mg/kg) also prolonged these parameters in a dose-dependent manner, however, the prolongation induced by bedripil was limited to shorter coupling intervals as compared with that induced by SD-3212. SD-3212 (0.1-1 mg/kg) did not show this prolonging effect.(ABSTRACT TRUNCATED AT 250 WORDS)

[Chronic lymphocytic leukemia diagnosed after corticosteroid therapy for Evans syndrome]

A 59-year-old woman was admitted in February 1991, because of abdominal distension. On admission, she had splenomegaly, autoimmune hemolytic anemia, and idiopathic thrombocytopenic purpura. Evans syndrome had been diagnosed and daily prednisolone therapy had been performed. After this therapy, a rapid increase of lymphocytes was observed accompanied with contraction of spleen. The monoclonal proliferation of B-lymphocytes and rearrangement of JH and J kappa gene were detected and chronic lymphocytic leukemia was diagnosed. With reduction of prednisolone, the lymphocyte counts decreased and the size of the spleen returned to the previous state. It is suspected that the cause of rapid lymphocytosis in this case was due to the redistribution of lymphocytes from the spleen to the peripheral blood.

Possibilities of the tolerance development to nipradilol and of the measurement of vascular glutathione content in isolated rat aorta

1. Nipradilol produced concentration-dependent relaxations of isolated rat aorta ring preparations under the contracture induced by norepinephrine or KCl, which were not significantly influenced by the previous incubation with nipradilol but significantly depressed by methylene blue. 2. The previous incubation with nipradilol did not influence the relaxant responses to nitroglycerin. 3. Five different methods for measurement of vascular glutathione content did not give the satisfiable results on the detected value of glutathione content in isolated rat aorta tissues. 4. Results indicate that nipradilol will not develop the tolerance to nipradilol itself and nitroglycerin.

[Establishment of an outbred strain (Jic: SUN) in the house musk shrew, Suncus murinus]

Planned reproduction of the house musk shrew, Suncus murinus was investigated using 3,016 females for mating. The birth rate and the weaning rate attained were 77.2% and 82.3%, respectively. The average litter size was 3.4. The mean value of the productive index (number of weaned individuals/number of females mated) was estimated as 2.2. The highest value of the productive index, 2.6, was recorded when the fourth litter was used for reproduction. No seasonal fluctuation in the reproductive ability was observed through the course of the present breeding. In the present study, we have maintained the closed colony of the house musk shrew for six years. This colony is established as a outbred strain, and is designated as Jic: SUN.

[A case of motor neuron disease with IgM gammopathy which showed anti-cerebrum antibody]

A patient, 50-year-old female, developed progressive weakness of lower extremities, and gait disturbance for 2 years. Neurological examination revealed hyperreflexia with pathological reflex, fasciculation in the limbs and tongue, muscle weakness and atrophy in distal limbs, but no sensory disturbance. Needle EMG showed neurogenic findings compatible with motor neuron disease (MND). Laboratory data showed polyclonal IgM hyperimmunoglobulinemia, positive several autoimmune antibodies including antisingle strand DNA antibody (Ab), ENAab, SS-A ab and RA. There were no antibodies for gangliosides and Myelin-associated glycoprotein (MAG), but positive antibody for 54KD protein of cerebral gray and white matter. The clinical manifestations including gait disturbance and muscle weakness, and serum IgM level were moderately improved by plasmapheresis which is considered important for consideration of causes of MND.

[Laboratory breeding of the red-backed vole (Clethrionomys rufocanus bedfordiae)]

Laboratory matings were attempted to establish breeding colonies of red-backed voles (Clethrionomys rufocanus bedformidae) as experimental animals. For these mating, 10 pairs of red-backed voles which were captured in the Tohbetsu region of Hokkaido, Japan and their litters were used. In the results for two years, 1987 to 1988, the rates of pregnancy, birth and weaning were 35.4%, 94.5% and 79.5%, respectively. The mean litter size was 5:1 +/- 1.6 with a range of 1 to 9. The mean gestation period was 20.0 +/- 0.7 days with a range of 18 to 22. These results suggest that planned production of red-backed voles in the laboratory is possible. To determine intraregional variations of red-backed voles with a view to the establishment of a strain by inbreeding, restriction patterns of mitochondrial DNAs using seven restriction endonucleases were compared. Four different patterns were obtained from wild red-backed voles used in the present study.

Comparison of the development of tolerance to nitroglycerin in aortic preparations isolated from non-diabetic and diabetic rats

To clarify whether or not tolerance to nitroglycerin is developed more easily in a diabetic than in a non-diabetic state, the effects of nitroglycerin on aortic preparations isolated from diabetic and non-diabetic rats were examined and compared with those of nicorandil, which has been known to develop less tolerance than does nitroglycerin. Contractile responses to norepinephrine, relaxant responses to nitroglycerin and nicorandil, and the tolerance development to nitroglycerin were found to be no different between diabetic and non-diabetic aortic preparations. N-Acetylcysteine preincubated together with nitroglycerin prevented the tolerance development to nitroglycerin in non-diabetic but not in diabetic aortic preparations. The results suggest that the tolerance to nitroglycerin is developed in the diabetic as well as in the non-diabetic state.

Structural details of ribonuclease H from Escherichia coli as refined to an atomic resolution

The crystal structure of RNase H from Escherichia coli has been determined by the multiple isomorphous replacement method, and refined by the stereochemically restrained least-squares procedure to a crystallographic R-factor of 0.196 at 1.48 A resolution. In the final structure, the root-mean-square (r.m.s.) deviation for bond lengths is 0.017 A, and for angle distances 0.036 A. The structure is composed of a five-stranded beta-sheet and five alpha-helices, and reveals the details of hydrogen bonding, electrostatic and hydrophobic interactions between intra- and intermolecular residues. The refined structure allows an explanation of the particular interactions between the basic protrusion, consisting of helix alpha III and the following loop, and the remaining major domain. The beta-sheet, alpha II, alpha III and alpha IV form a central hydrophobic cleft that contains all six tryptophan residues, and presumably serves to fix the orientation of the basic protrusion. Two parallel adjacent helices, alpha I and alpha IV, are associated with a few triads of hydrophobic interactions, including many leucine residues, that are similar to the repeated leucine motif. The well-defined electron density map allows detailed discussion of amino acid residues likely to be involved in binding a DNA/RNA hybrid, and construction of a putative model of the enzyme complexed with a DNA/RNA hybrid oligomer. In this model, a protein region, from the Mg(2+)-binding site to the basic protrusion, covers roughly two turns of a DNA/RNA hybrid double helix. A segment (11-23) containing six glycine residues forms a long loop between the beta A and beta B strands. This loop, which protrudes into the solvent region, lies on the interface between the enzyme and a DNA/RNA hybrid in the model of the complex. The mean temperature factors of main-chain atoms show remarkably high values in helix alpha III that constitutes the basic protrusion, suggesting some correlation between its flexibility and the nucleic acid binding function. The Mg(2+)-binding site, surrounded by four invariant acidic residues, can now be described more precisely in conjunction with the catalytic activity. The arrangement of molecules within the crystal appears to be dominated by the cancelling out of a remarkably biased charge distribution on the molecular surface, which is derived in particular from the separation between the acidic Mg(2+)-binding site and the basic protrusion.

Impaired induction of prolactin secretion from the anterior pituitary by suckling in streptozotocin-induced diabetic rat

Prolactin (PRL) secretion in streptozotocin-induced diabetic rats postpartum was examined to elucidate the reason for the reduced milk secretion of diabetic mothers. Pregnant Wistar rats were given citrate buffer (control group) or streptozotocin only (DM group) or with insulin (insulin group). Growth of pups was significantly lower in the DM group than in the control group, but similar in the insulin and control groups. Suckling-induced PRL secretion was significantly lower in the DM group than in the control group, and intermediate in the insulin group. TRH-induced PRL secretion was significantly lower in the DM group than in the control group, but the same in the insulin and control groups. Histologically, the mammary glands in the DM group were relatively less developed than those in the control group. The results suggest that reduced milk secretion in diabetic mothers is due to impaired induction by suckling of PRL secretion from the anterior pituitary as well as poor development of the mammary gland.

[Report of two cases of neonatal alloimmune thrombocytopenia caused by anti-HLA antibody, and their screening using umbilical cord blood]

Here reported are two cases with neonatal alloimmune thrombocytopenia (NAITP). In our 2 cases, anti-HLA antibodies, i.e. anti-HLA-A24+B51 and anti-HLA-Bw61+Cw3, respectively, were detected in the mother's sera, which reacted to each patient's lymphocytes and were presumed to have been contribute to NAITP. The thrombocytopenia, found on routine laboratory examination, recovered within 1 to 3 weeks without any therapy in both cases. Further, the relationship of platelet count and PAIgG in neonatal babies (umbilical cord blood) to anti-HLA antibodies in their mothers were examined in 284 pairs. Thrombocytopenia less than 150,000/microliters was found in 16/284 babies (5.6%), 3 of the 16 (1.1% of the total) being positive for anti-HLA, and one positive for PAIgG. Four (1.4%) of the 284 babies were positive for PAIgG, one of whom was thrombocytopenic, and one positive for anti-HLA. Anti-HLA antibody was found in 25/284 mothers (8.8%). Nevertheless, none of the pairs showed positive reactions in all of three tests. It seems that passive transfer of maternal anti-HLA antibodies to the fetus is not itself sufficient to cause thrombocytopenia. On the other hand, some NAITP cases may have been overlooked because of their mildness.

[The relationship of chewing ability to nutrient and food intakes in the community elderly]

The purpose of the present study is to investigate the relationship of chewing ability to nutrient and food intakes in the community elderly. Subjects consisted of 145 elderly residents (56 males, 89 females) ranging in age from 65 to 79 years, living at home in a village of Okinawa Prefecture. Chewing ability was divided into two categories: being able to chew ordinary foods was defined as "good", and being able to chew only soft foods as "bad". To determine quantitative food intakes 24-hour dietary records were utilized which were confirmed by nutritionists during interviews. Good chewing ability was found in 82.1% for males and 83.1% for females with no statistically significant difference concerning age or sex. Teeth status was significantly related to chewing ability. For both males and females, protein intake was lower in the group with bad chewing ability than in the good group. Only in males intakes of total energy, fats, Ca, and Fe were lower in the group with bad chewing ability. Concerning food items, intakes of dark green and yellow vegetables and fat in males, and intake of rice in females, were lower in the group with bad chewing ability.