Characterization of a cloned rat serotonin 5-HT1A receptor expressed in the HeLa cell line

We have previously isolated the rat serotonin (5-HT)1A receptor gene (G21Y2) and now report the expression and characterization of this receptor. The BamHI/Xbal fragment of this gene was cloned into Rc/RSV and stably transfected into HeLa cells by the calcium phosphate method. For determination of specific 5-HT1A receptor binding, [3H]8OH-DPAT was used as the radioligand and incubated with HeLa cell membranes. The cells expressed specific and saturable binding of [3H]8OH-DPAT with a Kd value of 0.3 nM and a Bmax value of 2 pmol/mg protein. GTP (50 microM) added to the incubation mixture increased the Kd value to 3 nM indicating that the expressed receptor is coupled to a G protein. The specific binding was inhibited by selective 5-HT1A partial agonists, such as buspirone, ipsapirone, gepirone, tandospirone, zalospirone and SUN8399 with Ki values of 1-30nM, whereas other neurotropic drugs except for spiperone (Ki = 46 nM) and nemonapride (Ki = 2.3 nM) were effective only at concentrations of more than 100 microM. The potencies of these compounds to inhibit [3H]8OH-DPAT from its specific binding sites were similar to their affinities determined in rat hippocampus binding studies. These data suggest that the expressed receptor is a 5-HT1A-type similar to 5-HT1A receptors in the rat hippocampus.

Lack of effect of haloperidol or methamphetamine treatment on the mRNA levels of two dopamine D2 receptor isoforms in rat brain

In order to investigate whether changes of the two mRNAs encoding the D2 receptor isoforms were induced by chronic haloperidol or methamphetamine treatment in rats, we measured the brain mRNA levels using in situ hybridization histochemistry (ISHH). We used two oligonucleotide probes, an "insert" probe to hybridize with the longer D2 receptor, D2(444), mRNA, and a "spanning" probe to hybridize with the shorter D2 receptor, D2(415), mRNA. Both D2 mRNAs were detected by ISHH in the caudate putamen, nucleus accumbens, substantia nigra, pars compacta and ventral tegmental area. The distributions and the amounts of the mRNAs for the two D2 isoforms did not change after chronic administration of haloperidol (1 mg/kg/day for 14 days, ip) or methamphetamine (4 mg/kg/day for 14 days, ip). These results suggest that the changes of D2 receptor density induced by chronic neuroleptic and psychostimulant treatment are not due primarily to receptor expression.

Protection by halothane of the vagal baroreflex system from transient global cerebral ischemia in dogs

A possible cerebroprotective effect of halothane was investigated in a canine model of 5-min global cerebral ischemia. In pentobarbital-anesthetized dogs, additional inhalation of 0.5 to 1% halothane prior to ischemia prevented the post-ischemic dysfunction of the vagal component of reflex bradycardia. In contrast, pretreatment with thiopental at 10 mg/kg, i.v. failed to prevent it. The influence of ischemia in the absence of anesthetics was similar to that under barbiturate anesthesia. The results suggest that halothane, but not barbiturate, may actively protect the vagal baroreflex system from ischemia.

Circulatory effects of denopamine in newborn piglets

Denopamine is an orally active beta 1 agonist whose cardiovascular action in the newborn is unknown. We evaluated its circulatory effects during normoxia in newborn piglets less than 7 days of age. The piglets were acutely instrumented under general anesthesia with an electromagnetic flow probe around the main pulmonary artery and catheters in the main pulmonary artery, aorta, left ventricle, and the right and left atria. A Millar high-fidelity catheter was used to measure left ventricular dp/dt. The ductus arteriosus was ligated. Denopamine was administered in the right atrium as a continuous infusion of 2, 4, and 8 micrograms/kg per min for 10 min each. Although cardiac index, heart rate and left ventricular dp/dt increased dose-dependently by 46.0 +/- 18.2%, 87.1 +/- 34.9% and 159.9 +/- 42.4%, respectively, stroke index was not significantly altered. Unlike pulmonary artery pressure (which increased dose-dependently), aortic pressure increased with 2 and 4 micrograms/kg per min denopamine, respectively, it fell with 8 micrograms/kg per min denopamine. Similarly, the systemic vascular resistance decreased with the high dose (8 micrograms/kg per min). There was no significant change in pulmonary vascular resistance. Denopamine is potently inotropic in the adult. However, its circulatory effect in the neonate is dependent on its chronotropic action. Furthermore, denopamine is a systemic vasodilator at high doses in the neonatal circulation.

Difference between halothane and barbiturate anesthesia in the influence of cerebral ischemia on the vagal baroreflex in dogs

In halothane-anesthetized dogs, a decrease in baroreflex sensitivity (BRS) of approximately 20% was observed during the reperfusion period following 5-min global cerebral ischemia. When compared with our previous study on animals under pentobarbital anesthesia, the extent of the decrease in BRS was smaller and apparently more severe ischemia was necessary to damage the vagal component of the baroreflex. Substitution of halothane with pentobarbital during the reperfusion period failed to affect either BRS or the ratio of the vagal component. In another group, pre- and post-ischemic measurements of BRS was performed under halothane anesthesia, but the ischemic insult was given under thiopental anesthesia. In these animals, the extent of decrease in BRS (about 50%) was greater than that in animals subjected to ischemia under halothane anesthesia. The present results suggest that the anesthetics used during the ischemic insult may affect the extent of post-ischemic dysfunction of the baroreflex. The vagal component of the baroreflex may be more resistant to ischemia under halothane anesthesia than under barbiturate anesthesia.

[A case report of patch aortoplasty for supravalvular aortic stenosis associated with Williams syndrome]

A 15-year-old girl underwent patch aortoplasty for supravalvular aortic stenosis in association with Williams syndrome. Pressure gradient of before and after stenosis of the aorta decreased from 104 mmHg to 16 mmHg at the postoperative catheterization. Angiography after the operation showed no stenosis. Postoperative course was excellent and discharged on 14th postoperative day. The problems of the operation of supravalvular aortic stenosis were discussed.

Removal of micro-organisms by filtration through unwoven cloth coated with a pyridinium-type polymer

Unwoven cloth coated with 32 mg/g of a copolymer of N-benzyl-4-vinyl-pyridinium chloride and styrene was found to be effective in removing micro-organisms from water. In experiments demonstrating removal of Escherichia coli by filtration through ten sheets of the unwoven cloth, the rate of removal was 99.99% at a filtration rate of 2.6 cm/h, and remained at 99% even at a high filtration rate of 300 cm/h and a low influent concentration of the bacterial cells such as 10(3) cells/ml. The rate of removal tended to increase with a decrease in the influent bacterial concentration. Seven other bacteria and two yeasts were effectively removed by filtration through the unwoven cloth. Filtration through the unwoven cloth was also effective in removing spores of fungi from water but was not very effective in removing bacteriophage T4 from aqueous solution.

Localization of the mRNAs for two dopamine D2 receptor isoforms in the rat brain

Two molecular forms of the dopamine D2 receptor were generated by alternative RNA splicing. To investigate the relative distributions of the two mRNAs encoding the D2 receptor isoforms, D2(415) and D2(444), we performed in situ hybridization histochemistry in the rat brain with the two oligonucleotide probes. An insert probe complementary to an additional fragment of the D2 receptor mRNA cloned from the rat brain, and a spanning probe complementary to its contiguous sequence were used. These 48 base probes were 3'-end labeled with [35S]dATP. The brains were dissected from male SD rats and frozen in dry ice and acetone. Cryostat sections (16 microns) were collected on gelatin coated slides and stored at -20 degrees C. In situ hybridization studies were conducted with a probe concentration of 1 x 10(6) dpm/100 microliters of buffer per brain slice at 37 degrees C for 18-20 h in a humid chamber. The slides were washed, dried and exposed to tritium sensitive film for one week. The autoradiograph showed that both mRNA were present at high levels in the corpus striatum, accumbens nucleus and substantia nigra (pars compacta). Identical patterns of labeling were obtained in the rat brain using both the insert and spanning probes, although the optical densities detected with the insert probe were higher than those with the spanning probe in the corpus striatum. This suggests that both D2 receptor mRNAs are expressed similarly in each region of the rat brain and D2(444) expressed dominantly in the corpus striatum.

[Early diagnosis of Mycoplasma pneumoniae pneumonia by antigen detection using immunobinding assay]

The possibility of rapid diagnosis of Mycoplasma pneumoniae infection by immunobinding assay is described. Immunobinding assay which was developed by Kotani and McGarrity is a simple and rapid method for identification of mycoplasmas. Small amounts of antigen were spotted onto the nitrocellulose membrane. It was treated with a specific rabbit antisera against M. pneumoniae. The antigen-antibody complex was visualised with the avidin-biotin horseradish peroxidase method. Cross reaction was seen between M. pneumoniae and M. genitalium. Throat swabs from hamsters infected with M. pneumoniae were positive on 7th and 14th day after infection. Although the cross reaction was seen between M. pneumoniae and M. genitalium, this method could be useful for rapid diagnosis of M. pneumoniae infection.

Relation of early hemodynamic changes to final cardiac phenotype and survival after neural crest ablation in chick embryos

BACKGROUND

Microcinephotography was used to study a model of persistent truncus arteriosus created in chick embryos by ablation of premigratory neural crest destined for the third and fourth aortic arch arteries as well as the septum of the cardiac outflow tract.

METHODS AND RESULTS

Twenty-five control embryos and 105 of 202 experimental embryos were filmed on day 3 of incubation and then reincubated. The remaining 97 experimental embryos were not filmed because of twisting of the embryos, but they were reincubated. There was no difference in either the survival rate (p greater than 0.23) from day 3 to day 11 of incubation or the incidence of persistent truncus arteriosus (p greater than 0.08) between the filmed and the nonfilmed embryos. Incomplete looping of the cardiac tube observed in experimental embryos during early cardiogenesis correlated with a right ventricular origin of the outflow vessels in the definitive heart. Hemodynamic measurements indicated that there was no difference in heart rate, ejection fraction, systolic and diastolic areas, stroke volume, and cardiac output between controls and the experimental group as a whole. However, embryos that did not survive to day 11 had decreased stroke volume (p less than 0.001) and cardiac output (p less than 0.001), whereas embryos that survived to day 11 with cardiac malformations had increased stroke volume and cardiac output in early embryogenesis.

CONCLUSIONS

Increased stroke volume and cardiac output may be necessary factors for survival in embryos with cardiac dysmorphogenesis and probably are associated with dilation of the ventricular portion of the cardiac tube, which leads to malalignment of the outflow vessel or vessels.

Temporospatial study of the migration and distribution of cardiac neural crest in quail-chick chimeras

It has been demonstrated that the septation of the outflow tract of the heart is formed by the cardiac neural crest. Ablation of this region of the neural crest prior to its migration from the neural fold results in anomalies of the outflow and inflow tracts of the heart and the aortic arch arteries. The objective of this study was to examine the migration and distribution of these neural crest cells from the pharyngeal arches into the outflow region of the heart during avian embryonic development. Chimeras were constructed in which each region of the premigratory cardiac neural crest from quail embryos was implanted into the corresponding area in chick embryos. The transplantations were done unilaterally on each side and bilaterally. The quail-chick chimeras were sacrificed between Hamburger-Hamilton stages 18 and 25, and the pharyngeal region and outflow tract were examined in serial paraffin sections to determine the distribution pattern of quail cells at each stage. The neural crest cells derived from the presumptive arch 3 and 4 regions of the neuraxis occupied mainly pharyngeal arches 3 and 4 respectively, although minor populations could be seen in pharyngeal arches 2 and 6. The neural crest cells migrating from the presumptive arch 6 region were seen mainly in pharyngeal arch 6, but they also populated pharyngeal arches 3 and 4. Clusters of quail neural crest cells were found in the distal outflow tract at stage 23.

[Surgical treatment of pulmonary atresia with intact ventricular septum in infancy--analysis of right ventricular growth potential after pulmonary valvotomy]

Our surgical experience involving pulmonary atresia with intact ventricular septum (PPA) between the years 1981 and 1989 is reviewed. Twelve infants aged 3 days to 11 months were studied for right ventricular growth potential with angiocardiography and hemodynamics after transventricular pulmonary valvotomy (TVPV). Ten infants were divided into two groups, 5 infants (Group I) were treated with TVPV only, and the other 5 infants (Group II) required additional surgery after the initial operation (TVPV in 2 cases and TVPV with shunt in 3 cases). Post-operative RV growth potential was evaluated with right ventricular index (RVI) based on the tricuspid valve annulus, right ventricular inlet, and right ventricular outlet dimensions, and with tricuspid annular index (TVI) based on the tricuspid valve annulus normalized by aortic diameter. Follow-up (3-69 months after initial operation) studies demonstrated that the RV cavity increased in Group I (RVI of 15.75 +/- 2.92 preoperatively versus 17.00 +/- 1.57 postoperatively, TVI of 3.04 +/- 0.63 versus 3.85 +/- 0.40). In contrast, the RV cavity in Group II demonstrated a lack of growth (RVI of 9.24 +/- 2.60 versus 9.85 +/- 2.76, TVI of 1.46 +/- 0.46 versus 1.70 +/- 0.80). PPA infants with RVI greater than 11 have been treated successfully with TVPV alone, which may maximize the potential for RV growth, but infants with RVI less than 11 have not experienced RV growth + postoperatively and, therefore, have required second intracardiac operations.

Spontaneous near closure of coronary artery fistula: Doppler echocardiographic findings

A 1-year-old girl was diagnosed as having a fistula between the left coronary artery and the right ventricle by selective coronary angiography. The left to right shunt ratio was 38%. At a second angiography, the fistula was markedly diminished in size. Turbulent flow was detected throughout the cardiac cycle in the left coronary artery and during systole in the right ventricle by Doppler echocardiography on the first visit. At 3 years of age the systolic component of the left to right shunt flow in the left coronary artery and the right ventricle was reduced in size. Doppler echocardiography proved useful in observing the natural history of this coronary artery fistula.

[The molecular biology of dopamine receptors]

In this article advances in the molecular biology of dopamine receptors are reviewed. Dopamine receptor subtypes D1, D2 and D3 have been cloned and characterized over the last three years. Analysis of their amino acid sequences has shown that these subtypes belong to the G protein-coupled receptor family, with seven transmembrane domains, a C-terminus within the cell and a N-terminus outside the cell. The distribution of mRNAs coding these receptors was determined by Northern blotting or in situ hybridization, and they were expressed in eukaryotic cells for application in such pharmacological experiments as receptor binding and cAMP accumulation. D1 receptors, which have 446 amino acids, were expressed in cells and detected by [3H]SCH23390 binding and cAMP accumulation assay. However, another paper described D1 as having 485 amino acids and suggested the existence of D1 receptor subclasses. D2 receptors have two isoforms, D2 (444) and D2(415), produced by alternative RNA splicing. D2 (444) has 29 additional amino acids in the third intracellular loop of D2(415). The mRNA distribution differs between D2 (444) and D2 (415), although the pharmacological profiles of the two isoforms are identical. The D3 receptor is localized in the limbic area of the brain and has a relatively high affinity for atypical neuroleptics and putative autoreceptor-selective agents. D3 appears to mediate some of the antipsychotic effects of the agents.

A double-blind study of the therapeutic efficacy of zinc gluconate on taste disorder

The therapeutic efficacy of orally given zinc gluconate on taste disorder was investigated by a double-blind study in 98 patients with a chief complaint of this disease. The subjects were divided into two 49-patient groups and were orally given zinc gluconate or the placebo for up to 4 months. Improvement of taste examination and subjective symptoms was analyzed in 65 of the subjects. Although no significant difference was detected between the two groups in overall efficacy, a significant superiority of zinc gluconate to placebo was observed in patients with idiopathic and zinc-deficient taste disorder. Comparison of the improvement by Ridit analysis showed a significant therapeutic superiority of zinc gluconate. In contrast, comparison of the degree of subjective symptomatic changes.

The effects of ablation of the visual cortical area on the formation of LTP in the superior colliculus of the rat

Postsynaptic potentials (PSPs) were recorded on the surface of the rat in the superior colliculus (SC) after electrical stimulation of the optic nerve. Long-term potentiation (LTP) was elicited in the PSP by tetanic stimulation of the optic nerve either when the ipsilateral visual cortex was removed or when a GABA antagonist, picrotoxin, was administered before the tetanic stimulation. These results suggest that the corticotectal tract may inhibit the appearance of LTP via the GABAergic interneurons within the superficial gray layer (SGL).

Involvement of a protein kinase C-dependent process in long-term potentiation formation in guinea pig superior colliculus slices

Superior colliculus (SC) slices were prepared from guinea pig. Electrical stimulation was applied to the optic layer (OL) of the SC slices and the postsynaptic potential (PSP) was evoked in the superficial grey layer (SGL) of the SC. Tetanic stimulation to the OL evoked long-term potentiation (LTP) in the PSP. To investigate the involvement of the protein kinase C (PKC) system on the LTP formation in the SC, the effects of PKC activator (phorbol ester) and PKC inhibitors (polymyxin B, melittin and H-7) on the LTP formation have been studied. Application of phorbol ester to the medium at concentrations between 10(-8) and 10(-10) M increased the amplitude of the PSP. On the other hand, the presence of phorbol ester at a concentration of 10(-6) M increased the glutamate release from the SGL slices. Tetanic stimulation which could not induce LTP by itself could elicit LTP during application of phorbol esters at the low concentration (3 X 10(-12) M). PKC inhibitors such as polymyxin B (10(-7) M), melittin (10(-8) M) and H-7 (10(-4) M) prevented LTP formation. When H-7 was applied once after LTP was formed, the enhanced PSP reduced to the original level. These results strongly indicate the involvement of PKC system on the LTP formation in the SC slices.

Selective dysfunction of the vagal component of the baroreflex following cerebral ischemia: protection by ifenprodil and flunarizine

Baroreflex sensitivity assessed from the phenylephrine-induced reflex bradycardia was significantly decreased following 5 min global incomplete cerebral ischemia in pentobarbitalized dogs. Although bilateral vagotomy in the cervical region decreased baroreflex sensitivity by about 50% in sham-operated animals, it hardly affected the baroreflex in animals subjected to ischemia. The extent of the decrease in the influence of vagotomy on the baroreflex was dependent on the severity of ischemia in the dorsal medulla oblongata. In animals vagotomized before ischemia, no significant decrease in baroreflex sensitivity was observed following ischemia. Pretreatment with ifenprodil or flunarizine, 1 mg/kg i.v., 5 min prior to ischemia prevented the post-ischemic decrease in baroreflex sensitivity. Vagotomy decreased baroreflex sensitivity during the reperfusion period in these treated animals. These results suggest that the post-ischemic attenuation of reflex bradycardia may be due to a selective dysfunction of the vagal component of baroreflex, which can be prevented by the cerebroprotective agents.

Prevention of acquired immunodeficiency syndrome and hepatitis B. Part IV: The effect of impression material on glutaraldehyde solution

Immersion of dental impressions in 2% glutaraldehyde has been shown to be an effective disinfection procedure for viral contamination. This study compared the effect of immersing impression materials on the concentrations of glutaraldehyde. Contamination with saliva slightly affected the concentration of glutaraldehyde. Irreversible hydrocolloid impression material markedly decreased the concentration of glutaraldehyde, whereas the immersion of silicone rubber impression material only slightly affected the concentration of glutaraldehyde. Attention should be paid to the concentration of glutaraldehyde solution when irreversible hydrocolloid impression material is immersed in the disinfectant.

Depression in members of a new religious sect in Japan

We investigated 226 people belonging to a regional church of a new religious sect (hereinafter referred to as religious group) and 899 ordinary people living in the rural area near this church (hereinafter referred to as nonreligious group) with a questionnaire using Zung's Self-Rating Depression Scale (SDS). In males ranging in age from 40 to 69, the mean scores of 7 SDS items out of 20 were significantly higher in the religious group than in the nonreligious group. Males at the age of 70 or older in both groups, however, did not show any significant difference in these items. It suggests that the religious affiliation exerted mentally good effects on the older male members.