Phosphorylation of rat brain nicotinic acetylcholine receptor by cAMP-dependent protein kinase in vitro

The participation of protein kinases in phosphorylation of nicotinic acetylcholine receptor (nAChR) in electric organ and muscle has been precisely investigated in vitro and in vivo whereas phosphorylation of neuronal nAChR is not yet fully characterized. Here, we first report the in vitro phosphorylation of brain nAChR. nAChR purified from rat brains was phosphorylated in vitro by cAMP-dependent protein kinase (PKA), immunoprecipitated with monoclonal antibody against the receptor, and subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by autoradiography. PKA specifically phosphorylated nAChR on the alpha 4 subunits, and H8, an inhibitor of PKA, inhibited completely the phosphorylation. Under the conditions used, a maximal stoichiometry of the phosphorylation by PKA was near to 1 mol of phosphate/mol of the alpha 4 subunits. The 32P-labeled subunits were digested with S. aureas V8 protease followed by SDS-PAGE autoradiography and the resultant phosphopeptide maps revealed three distinct phosphopeptide bands, one major band and two minor bands. Phosphoamino acid analysis of the 32P-labeled alpha 4 subunits showed that serine residues were exclusively phosphorylated. Based on these results, participation of PKA in the regulation of neuronal nAChR is discussed.

Effects of increased cerebrospinal fluid pressure on cochlear and cerebral blood flow

We investigated the effects of increased cerebrospinal fluid (CSF) pressure on cochlear blood flow (CoBF) and cerebral blood flow (CBF) in guinea pigs. CoBF and CBF were recorded simultaneously using two laser-Doppler flowmeters, and blood flow volume in each part of the cochlea and the brain was measured by the non-radioactive microsphere method. CoBF was reduced by increased CSF pressure but the reduction was not persistent. Although inner ear pressure was elevated to the same level as CSF pressure, CoBF was not decreased by the pressure elevation as much as was CBF. Our results suggest that CoBF is relatively resistant to increases in CSF pressure.

Molecular cloning of a human cDNA encoding a novel protein, DAD1, whose defect causes apoptotic cell death in hamster BHK21 cells

The tsBN7 cell line, one of the mutant lines temperature sensitive for growth which have been isolated from the BHK21 cell line, was found to die by apoptosis following a shift to the nonpermissive temperature. The induced apoptosis was inhibited by a protein synthesis inhibitor, cycloheximide, but not by the bcl-2-encoded protein. By DNA-mediated gene transfer, we cloned a cDNA that complements the tsBN7 mutation. It encodes a novel hydrophobic protein, designated DAD1, which is well conserved (100% identical amino acids between humans and hamsters). By comparing the base sequences of the parental BHK21 and tsBN7 DAD1 cDNAs, we found that the DAD1-encoding gene is mutated in tsBN7 cells. The DAD1 protein disappeared in tsBN7 cells following a shift to the nonpermissive temperature, suggesting that loss of the DAD1 protein triggers apoptosis.

An anatomic study on the Martin-Gruber anastomosis

The incidence of Martin-Gruber anastomosis was studied. Anatomical dissection of 108 cadaveric arms was performed. The Martin-Gruber anastomosis was found in 23 arms. This anastomosis was classified into four types: Type Ia: Communication between the anterior interosseous and the ulnar nn. (n = 13), Type Ib: Communication between the median and ulnar nn. (n = 1), Type II: Communication between muscular branches of the flexor digitorum profundus m. (n = 8), Type III: Combination of Type Ia or Ib and Type II (n = 1). The incidence of Martin-Gruber anastomosis was found to be significantly higher in the present study than in previous studies.

Postexposure prophylaxis of varicella in family contact by oral acyclovir

OBJECTIVE

To determine whether varicella can be prevented by administration of oral acyclovir (ACV) during the incubation period of the disease.

SUBJECTS AND METHODS

ACV (40 or 80 mg/kg daily in four divided doses) was given orally to 25 exposed infants and children for 7 days, starting 7 to 9 days after exposure from the index case in their families. Their clinical features were compared with those of 25 age-matched control subjects who had been exposed in their families but did not receive ACV. A fluorescent antibody to membrane antigen assay was used for determination of the antibody to varicella-zoster virus, and a nested polymerase chain reaction method was used for detection of viremia.

RESULTS

Among the 25 who received ACV, 4 (16%) developed the disease and 1 (4%) had a fever. On the other hand, all of 25 control subjects developed the disease and 17 (68%) had a fever. The incidence of fever and the severity of skin rashes were significantly lower (P < .01) in the subjects who received oral ACV than in the control group. Seroconversion was observed in 84% of subjects who received ACV. In some cases, varicella-zoster virus DNA was detected by polymerase chain reaction amplification in peripheral blood mononuclear cells from blood drawn approximately 14 days after exposure.

CONCLUSIONS

Varicella can be prevented or modified by administration of oral ACV late in the incubation period.

Nicotine metabolism by rat hepatic cytochrome P450s

Many kinds of cytochrome P450s were purified from rat hepatic microsomes, and their role in the metabolization of nicotine in a reconstituted system examined. Of four phenobarbital-inducible P450s, P450 2B1 had the highest nicotine oxidation activity and P450 2B2 showed a low rate of nicotine oxidation, whereas P450 2C6 and 3A2 had no detectable activity toward nicotine. Among eleven other purified cytochrome P450s tested, P450 2C11 had high nicotine oxidation activity and P450 1A2 and 2D1 showed low catalytic activity toward nicotine. The other cytochrome P450s, P450 1A1, 2A1, 2A2, 2C7, 2C12, 2C13, 2E1 and 4A1, had no detectable nicotine oxidation activity. Based on these results, participation of cytochrome P450s in nicotine metabolism in human and animal livers is discussed.

Clinical and virological analyses of 21 infants with exanthem subitum (roseola infantum) and central nervous system complications

Twenty-one infants who had virologically confirmed exanthem subitum and central nervous system (CNS) complications were studied to elucidate the clinical features, laboratory and virological findings, and outcome. The primary infection with human herpesvirus 6 was confirmed by isolation of the virus from blood, a significant rise in the antibody titers to the virus, or both. All convulsive seizures (15 generalized and 6 focal) occurred during the pre-eruptive stage of exanthem subitum. Four infants with encephalitis/encephalopathy had more severe clinical features with abnormalities demonstrated on electroencephalograms and cerebral computed tomograms. All infants except those with encephalitis/encephalopathy recovered without any sequelae. One infant with encephalitis/encephalopathy developed epilepsy and another one died. Human herpesvirus 6 DNA amplified by the nested polymerase chain reaction method was detected in the cerebrospinal fluid of 6 infants, including 3 with encephalitis/encephalopathy, of 11 patients examined by the fifth day of the illness. These findings suggest that CNS complications including encephalitis/encephalopathy occur at the pre-eruptive stage of exanthem subitum, that human herpesvirus 6 invades the CNS in some patients, and that the outcome is not always benign.

[Transient ischemic dilatation of the left ventricle observed on dipyridamole-stressed thallium-201 scintigraphy]

To assess clinical significance of transient ischemic dilatation of the left ventricle (TID) on dipyridamole-stressed 201Tl myocardial scintigraphy, 110 patients suspected with coronary artery disease, including 13 with normal coronary, 48 with single vessel disease, 30 with 2 vessel disease, and 19 with 3 vessel disease were analyzed. TID was visually and quantitatively assessed calculating the ratio of the area within the left ventricular region on the initial and delayed image (TID ratio). TID was observed in 3 of 1 vessel disease (6%), 5 of 2 vessel disease (17%), and 8 of 3 vessel disease (42%). None of normal coronary artery showed TID. In patients with multivessel disease (MVD), TID was observed more frequently (27%) than in patients with 1 vessel disease (6%) (p < 0.025). Furthermore, the TID ratio tended to be higher (1.15 +/- 0.11) than those with single vessel disease (1.03 +/- 0.03). To identify patients with MVD, TID had a sensitivity of 27% and a specificity of 95%. ECG changes were observed more often in patients with TID than those without TID. Five patients showing TID underwent coronary artery bypass graft surgery, TID disappeared postoperatively in each patient. In conclusion, TID on dipyridamole 201Tl scan seems to be a specific although not sensitive marker for detecting MVD.

Effect of trimebutine maleate on emptying of stomach and gallbladder and release of gut peptide following a solid meal in man

We investigated the effect of orally administered trimebutine maleate on gastric and gallbladder emptying and on the release of gut peptide, pancreatic polypeptide (PP), and gastrin in humans for 120 min after ingestion of a solid meal. Gastric emptying was measured by a radionuclide technique. Gallbladder emptying was estimated by real-time ultrasonography. The oral administration of 200 mg of trimebutine maleate significantly shortened the lag time in starting gastric emptying (P < 0.05). Considering gallbladder emptying, trimebutine significantly inhibited the fasting emptying induced by neural reflex. Postprandially, there was a tendency toward an accelerated gallbladder emptying in the early phase. Neither the maximal percentage of gallbladder emptying nor the time of peak gallbladder emptying were affected. Trimebutine significantly blunted the post-prandial PP response in the cephalic and gastric phases, reflecting a vagal-cholinergic activity (P < 0.05). The PP response in the intestinal phase was also blunted. Gastrin release was significantly augmented only during the period of fasting after drug administration (P < 0.05). The major effect of trimebutine maleate appears to be a shortening of the lag time at the start of gastric emptying probably via its anticholinergic activity.

Effects of bile acids and taurine on the lipid fluidity of hepatic microsomes in normal and bile duct-ligated rats--a spin label study

In cholestasis and obstructive jaundice, hepatic bile acids and taurine content increase significantly and bile acids change in compositions. For example, increases in cholic acid, beta-muricholic acid and taurine-conjugated bile acids occur in rats. In this study, to clarify the significance of changes in bile acid composition in obstructive jaundice, the effects of various bile acids and taurine on the fluidity of the hepatic microsomal membrane were studied by the electron spin resonance spin-label method in normal and bile duct-ligated (for 10 days) rats. The flow properties (order parameter) of the shallow and deep layers of the membrane were determined with 5- and 12-doxyl stearic acid, respectively. Bile acids mainly affected the fluidity of the shallow membrane layer. The fluidity of the hepatic microsomal membrane was decreased in bile duct-ligated rats. Conjugated cholic acid (taurine-conjugated cholic acid, glycine-conjugated cholic acid and non-conjugated beta-muricholic acid exerted effects that increased fluidity in comparison with non-conjugated cholic acid and chenodeoxycholic acid, a precursor of beta-muricholic acid. Taurine had no clear effect on fluidity. In conclusion, cholic acid conjugation and beta-muricholic acid formation may be mechanisms which protect against the decrease in lipid fluidity of hepatic biomembranes in cholestasis or obstructive jaundice. Taurine may also affect fluidity through the formation of taurine-conjugated bile acids.

Phospholipase C activity in cerebrospinal fluid following subarachnoid hemorrhage related to brain damage

Phosphoinositide-specific phospholipase C (PLC) activities were measured in CSF from patients after subarachnoid hemorrhage (SAH). Their PLC activities were significantly higher than those in control CSF. Moreover, there was an obvious correlation between the PLC activity in CSF collected on day 3 and the preoperative clinical grade. The PLC activity was also closely correlated with the level of neuron-specific enolase as a marker of brain damage. Furthermore, the PLC activities were partially purified from CSF of patients after SAH and were immunologically identified to be PLC beta, PLC gamma, and PLC delta. These results suggest that PLCs are released into the CSF from brain tissue in conjunction with the initial hemorrhage and that their activity may reflect the extent of brain damage.

Bacteremia resulting from prostatic surgery in patients with or without preoperative bacteriuria under perioperative antibiotic use

We investigated the source of organisms detected in blood specimens obtained during and immediately following prostatic surgery under perioperative antibiotic use, as related to the results of cultures of preoperative urines and prostatic tissues. Ninety patients with benign prostatic hyperplasia were studied. The incidence of bacteremia was 28.9%: 53.7% in patients with preoperative bacteriuria and 8.2% in those without bacteriuria, a significant difference (p < 0.01). Of these bacteremic patients, 5, who had preoperative bacteriuria, developed septicemia. Bacteremia developed more frequently in patients with positive than in those with negative prostatic cultures; this difference was significant (p < 0.05). The species in 80.8% of the isolates from blood specimens were identical with those isolated from preoperative urines, and the species in 53.8% were identical with those from prostatic tissues. These results indicate that in patients with urogenital infection, especially bacteriuria, septicemia can result from prostatic surgery even under perioperative antibiotic use. The incidence of postoperative bacteriuria was approximately 20% in the preoperative nonbacteriuric patients regardless of the duration of chemoprophylaxis.

Application of a self-expanding metallic stent to a strictured esophagojejunostomy

We placed a Gianturco self-expanding metallic stent across the recurrent stricture of an esophagojejunostomy in a patient with gastric cancer. Though excellent passage of food resulted, intractable reflux occurred. Two months later the patient succumbed to recurrent tumor. At autopsy, the stent was patent and was partially covered by esophageal mucosa. There were narrow but deep ulcers around the stent hooks. The Gianturco metallic stent may provide an additional option for treating recurrent enteric strictures after other methods fail. Further refinements of the technique appear necessary.

Oxytocin modulates oxytocin neurons in the paraventricular nuclei of female rats throughout pregnancy and parturition

OBJECTIVE

The physiologic roles of nonphasic firing oxytocin neurons in the paraventricular nucleus of female rats throughout pregnancy and parturition was studied from the viewpoint of changes in the membrane activities.

STUDY DESIGN

Thin colonal hypothalamic slices containing the paraventricular nucleus were prepared. Immunohistochemical studies of oxytocin in the paraventricular nucleus were performed to determine the localization of oxytocin-containing neurons. Extracellular single neural activities were recorded with a glass micropipette from the oxytocin-dense area, and physiologic concentrations of oxytocin were applied.

RESULTS

Nonphasic firing activity was recorded from 61 neurons in virgin female, pregnant, delivering and lactating rats. After bath application of < 5.0 x 10(-11) mol/L of oxytocin, firing rates of 12 of 17 paraventricular neurons in virgin rats decreased and only one increased, whereas the remaining four showed no response to oxytocin. In pregnancy at day 15 all four neurons decreased in activity, whereas at day 21 rats 20 of 26 neurons decreased, two increased, and four showed no response. On the contrary, in delivering rats seven of eight neurons exhibited excitatory responses, and only one showed no response. This excitation reversed to inhibition again after the lactating period ended.

CONCLUSION

Negative feedback by oxytocin in virgin and pregnant rats might reverse to positive feedback in delivering and lactating animals as a result of changes in hormonal conditions. This reverse might be closely related to the initiation of delivery.

An accessory extensor digiti minimi arising from extensor carpi ulnaris

In a study of an accessory extensor digiti minimi arising from extensor carpi ulnaris in 240 upper limbs, an accessory tendinous slip originating from extensor carpi ulnaris was observed in the tunnel of the 6th compartment at the wrist in 82 (34.2%). The slip inserted into one of several sites on the 5th metacarpal bone, such as on the base with the main tendon (29.6%), on the midportion (2.5%) or on the head (1.7%). The last type of accessory tendinous slip, which was connected with the extensor aponeurosis of the little finger, is the accessory extensor digiti minimi arising from extensor carpi ulnaris described by Kaplan & Spinner (1984).

Spontaneous passage of upper urinary tract calculi in relation to composition

The composition of 2,755 calculi obtained from the upper urinary tract (1,409 by spontaneous passage and 1,346 by urological procedures) was analyzed using an infrared spectrophotometer, and the spontaneous passage rate was investigated in relation to the composition as well as other variables, such as stone size, and patient age and sex. Mixed stones of calcium oxalate and calcium phosphate were most frequently found, followed by those of calcium oxalate. The mean size (the maximum diameter) was largest in struvite stones and smallest in calcium oxalate ones. The sizes of stones from women were significantly larger than those from men (p < 0.01). As expected, the stone passage rates were inversely related to increasing stone size. The size of 55.6% of the stones passed was < or = 5 mm, and that of 96.6% of the stones < or = 10 mm.

Occurrence of melanosome-containing Merkel cells in mammalian oral mucosa

The occurrence and fine structure of Merkel cells with melanosomes in the labial epithelium of the dog and cat were studied by electron microscopy. These melanosomes were polarized in the Merkel cell cytoplasm opposite to the major aggregation of dense-cored granules and the closely abutting nerve terminal. None of melanosomes was found in the Golgi complex region where a few immature dense-cored granules were observed. This may suggest that the melanosomes are not produced in the Merkel cell, but are taken from the melanocytes like in keratinocytes. The possible phagocytotic ability of Merkel cells is discussed.

Antimicrobial treatment for chronic prostatitis as a means of defining the role of Ureaplasma urealyticum

A study was conducted to assess the clinical and microbiological effects of antimicrobial treatment for chronic prostatitis as a means of defining the role of Ureaplasma urealyticum. Significant U. urealyticum cells were considered to be isolated from the prostates of 18 of 143 prostatitis patients. These patients with ureaplasma-associated prostatitis were randomly treated with either ofloxacin or minocycline for 2 weeks; 4 patients were excluded due to voluntary withdrawal. U. urealyticum was eradicated in all the patients. Symptoms were resolved in 10 patients, and leukocytes in expressed prostatic secretion were cleared in 4 patients; both drug treatments revealed similar results. Even if we exclude 3 patients with significant coexistent Staphylococcus epidermidis cells before treatment, 3 of 11 patients evaluated showed complete resolution of symptoms and clearance of leukocytes in expressed prostatic fluid. These results suggest that U. urealyticum is a causative organism in some patients with chronic prostatitis.

Assessment of pulmonary artery pressure by pulsed Doppler echocardiography in patients with chronic pulmonary diseases

Doppler echocardiography was recently developed for obtaining a flow velocity profile at any point in the cardiac chamber. A pulsed Doppler technique combined with cross sectional echocardiography was used to examine the flow velocity pattern in the right ventricular outflow tract in 32 patients with chronic pulmonary disease (CPD) and in 15 healthy subjects as controls. All patients underwent cardiac catheterization. Pulmonary flow velocity profiles in the right ventricular outflow tract were recorded simultaneously with electrocardiograms and pre-ejection periods (PEP), right ventricular ejection time (RVET), acceleration time (AT), and calculated PEP/RVET, AT/RVET were determined. All normal subjects had "dome-like" flow velocity patterns with a peak flow at the midsystole. In patients with CPD, there was a significant correlation between log10MPAP (mean pulmonary arterial pressure) and AT/RVET, the coefficient being r = -0.623, between PVR (pulmonary vascular resistance) and AT/RVET (r = -0.52), and between SVI (stroke volume index) and PEP (r = -0.645). Complications of pulmonary hypertension in CPD were relatively mild, but the pulsed Doppler technique was found useful for evaluating pulmonary arterial pressure and other right heart hemodynamics of CPD patients.

Oxytocin inhibits nonphasically firing supraoptic and paraventricular neurons in the virgin female rat

Nonphasically firing activities were recorded from neurons in the supraoptic (s.o.) and paraventricular (p.v.) nucleus of the virgin female, male, and ovariectomized rat hypothalamic slice preparations. Following bath application of oxytocin (OXT), less than 1.0 x 10(-8) M, 24 (75%) of 32 virgin female s.o. neurons showed inhibitory responses and only one neuron showed excitatory response. In contrast to virgin female, five (63%) of eight male s.o. neurons were excited by OXT application. The same tendency was shown in the p.v. neurons. Among six s.o. neurons obtained from ovariectomized virgin rats, five neurons increased their firing rate to the application of OXT. After blocking synaptic transmission, the inhibitory responses of virgin s.o. neurons and the excitatory responses of ovariectomized virgin s.o. neurons to application of OXT were still observed with equal configurations. These findings suggest that the responses of nonphasic neurons to OXT may not due to synaptic drives.

Clinical analysis of a series of vertebral aneurysm cases

We reviewed 38 cases of aneurysms of the vertebral artery treated over the last 10 years: 26 (68%) located at the junction of the vertebral and posterior inferior cerebellar arteries, 10 (26%) at the vertebral artery, and 2 (5%) at the vertebrobasilar union. There were three distinct forms of aneurysms: 20 saccular (53%), 10 fusiform (26%), and 8 dissecting (21%). Among these 38 aneurysms, 33 (87%) had ruptured: 18 of the saccular aneurysms (90%), all 10 of the fusiform aneurysms (100%), and 5 of the dissecting aneurysms (63%). Computed tomography of the 28 ruptured aneurysms revealed diffuse subarachnoid hemorrhage in the basal cistern combined with intraventricular hemorrhage in 24 cases (86%). Magnetic resonance imaging was useful for differentiating between fusiform and dissecting aneurysms. Abnormalities such as a double lumen of the vertebral artery were demonstrated in four of the dissecting aneurysms. The overall surgical results were good for 22 of the 27 surgically treated cases (81%). New bleeding was observed in 8 (24%) of the 33 ruptured aneurysms. The rate of new bleeding was high (60%) in the patients with dissecting aneurysms, and occurred mostly in the acute stage. The incidence of vasospasm was 27%, and only two patients suffered permanent neurological deficits. These findings indicate that the rate of new bleeding tends to be high in patients with saccular and dissecting aneurysms, and thus, they should be treated as early as possible. A preoperative balloon occlusion test should be conducted if proximal occlusion of the vertebral artery is necessary, since proximal occlusion is not always safe, despite angiographic evidence of sufficient contralateral arterial flow.

Fatal encephalitis/encephalopathy in primary human herpesvirus-6 infection

An encephalitic illness with a fatal outcome occurred in a 9 month old girl with virologically confirmed exanthem subitum. Human herpes-virus-6 (HHV-6) DNA was found in the cerebrospinal fluid at the acute stage of the disease by the polymerase chain reaction, but the virus antigen was not detected in her brain tissue. This suggests that HHV-6-induced encephalitis/encephalopathy may be due to a non-infectious process.

Effects of acute administration of nicotine on convulsive movements and blood levels of corticosterone in old rats

The convulsive movements, blood levels of corticosterone and pharmacokinetics of nicotine after an acute intraperitoneal injection of nicotine (5 mg/kg) were examined in young (6-week-old) and old (2-year-old) rats. In pharmacokinetic study, blood nicotine levels during the elimination phase were significantly higher in old rats than in young rats. However, the duration of convulsions and the elevation of corticosterone levels after the nicotine injection showed significant decreases in old rats compared with those in young rats. These differences of nicotine-induced responses between young and old rats may be involved in the decrease in nicotine sensitivity.

Activation of human herpesvirus-6 in children with acute measles

Virological and serological studies were carried out prospectively to evaluate the possible activation of human herpesvirus-6 (HHV-6) in 50 infants and children with acute measles by isolation of HHV-6 from peripheral blood and by determining neutralizing antibodies to the virus. All but 5 patients (90%) were seropositive to HHV-6 in the acute stage of measles and 18 (40%) had a significant increase in HHV-6 antibody titers thereafter, whereas only 2 of 27 patients who were initially seropositive to Epstein-Barr virus (EBV) viral capsid antigen (VCA) had a significant rise in antibody titers to EBV VCA. Among 18 patients with a significant increase in HHV-6 titers, the virus was isolated from the peripheral blood mononuclear cells of three patients in the early convalescent stage of measles. These results indicate that activation of HHV-6 may occur frequently a few weeks after primary infection with the measles virus.