Genotyping of mouse hepatitis virus strains by restriction endonuclease analysis of amplified nucleocapsid protein genes

Restriction endonuclease analysis of amplified nucleocapsid protein genes from mouse hepatitis virus (MHV) was used to differentiate 12 strains isolated from mouse liver or transplantable tumors from five facilities, and the restriction patterns of the isolates were compared with those of five well-defined MHV strains, A59, JHM, 2, S and Nu-67. The patterns of 10 isolates from three facilities were the same as that of Nu-67. The remaining two isolates revealed different patterns from the five reference strains. This study showed that reverse transcription and the polymerase chain reaction assay based restriction analysis are feasible for the detection and genotyping of MHV, and the Nu-67 related strain was the most prevalent type found in the clinical samples.

Molecular identification of guanine-nucleotide-binding regulatory proteins which couple to endothelin receptors

The coupling of two endothelin receptor subtypes (ET(A) and ETB) to several types of guanine-nucleotide-binding regulatory protein (G protein) was examined. Two subtypes of receptor cDNAs were transfected alone or together with four different G protein alpha subunit cDNAs in COS-7 cells. In ET(A) receptor-transfected cells, endothelin-1 (ET-1) activated phosphatidylinositol-specific phospholipase C as measured by the production of phosphatidylinositol 1,4,5-trisphosphate [Ins(1,4,5)P3]. ETB-receptor-transfected cells also produced Ins(1,4,5)P3 on stimulation by ET-1. The ET-1-induced production of Ins(1,4,5)P3 was markedly higher in G alpha q-cotransfected or G alpha 11-cotransfected cells than in cells transfected with each receptor alone. ET-1 also stimulated production of cAMP in ET(A) or ETB receptor-transfected cells. The production of cAMP was synergistically amplified by G alpha s co-transfection with each receptor. In contrast, when G alpha i2 was co-transfected with the ET(A) or ETB receptor, ET-1 displayed an inhibitory action on forskolin-stimulated cAMP accumulation. Pertussis-toxin treatment of the G alpha i2-transfected cells resulted in abolition of the endothelin-induced inhibition of cAMP accumulation. These observations indicate that both ET(A) and ETB receptors are able to couple to Gq, G11, Gs and Gi2, and suggest that endothelin receptors stimulate multiple effectors via several types of G protein simultaneously. The overall effects induced by endothelin may differ in cell types depending on the level of expression of each G-protein subtype in the cell.

Effects of pyridoxalated hemoglobin polyoxyethylene conjugate and other hemoglobin-related substances on arterial blood pressure in anesthetized and conscious rats

The effects of pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) and other hemoglobin-related substances on arterial blood pressure (ABP) and heart rate (HR) were examined. Infusion of PHP and other hemoglobin-related substances elevated ABP and increased HR. The degree of the increase in ABP and HR did not differ among the groups. There were species' differences in responses to PHP. Pretreatment with various blockers did not abolish the elevation of ABP. The pretreatment of NG-monomethyl-L-arginine dose-dependently reduced the elevation of ABP but did not completely abolish it. PHP also elevated ABP in conscious rats. The magnitude of the ABP elevation was significantly smaller than in the anesthetized rats. Results indicate that inhibition of nitric oxide (NO) might be responsible in part for the elevation of ABP, and the degree of the elevation would be dependent on the degree of contribution of NO to the regulation of ABP.

Modulation of glomerular endothelin and endothelin receptor gene expression in aminonucleoside-induced nephrosis

This study assessed glomerular endothelin (ET)-1, ET-3, and ET-receptor A and B mRNA levels in puromycin aminonucleoside (PAN)-induced nephrosis. During the nephrotic stage, 8 days after PAN injection, ET-1 and ETB receptor mRNA were elevated by 2.8 +/- 0.8-fold (P < 0.01) and 2.4 +/- 0.9-fold (P < 0.01), respectively, as compared with controls. These mRNA levels decreased to control levels by Day 20, when the nephrosis was in remission. In contrast, glomerular ETA receptor mRNA levels did not change in PAN nephrosis or control rats during the experimental period. ET-3 mRNA was not detected in the glomeruli of PAN nephrosis or control rats. Additionally, plasma ET concentration and glomerular ET production were measured in PAN nephrosis and control rats by radio-immunoassay. Eight days after PAN injection, ET-1 levels in plasma and glomeruli were not significantly altered in rats with PAN-induced nephrosis (glomeruli, 104.68 +/- 16.46 pg/mg of protein versus 98.24 +/- 13.68 pg/mg of protein; plasma, 2.68 +/- 1.10 versus 2.52 +/- 0.98 pg/mL). The administration of methylprednisolone to PAN rats resulted in the rapid disappearance of proteinuria and partially attenuated the increased ET-1 and ETB receptor gene expression in the glomeruli. These data indicate that glomerular ET-1 and ETB receptor expression in PAN nephrosis in increased at the mRNA level and that methylprednisolone treatment results in an attenuated increase.

Hydrophobic accessible surface areas are proportional to binding energies of serine protease-protein inhibitor complexes

For analysis of enzyme-protein inhibitor interactions, we calculated the buried hydrophobic and hydrophilic accessible surface areas (ASAs) of enzymes and primary contact regions. In the five enzyme-protein inhibitor complexes so far analyzed, we found that the hydrophobic ASAs buried between the enzyme and the primary contact region are proportional to their experimental binding energies. This finding indicates that the hydrophobic interaction drives the binding of enzymes with protein inhibitors.

[Status epilepticus in two patients with Sotos syndrome]

Two patients with Sotos syndrome showed very intractable and prolonged status epilepticus, resulting in poor outcomes. Clinical seizures and EEG abnormalities in patients with Sotos syndrome are sometimes noted, but they are usually mild. These two patients showed hypoplasia of corpus callosum on MRI. We considered the mechanism of intractable seizures, and emphasized the importance of careful management for their seizures and EEG abnormalities.

[Relative size of the ventricle to the hemisphere in the neonatal MRI]

Using a software program for measuring surface area, we quantified the relative size of four parts of the lateral ventricles, including the body, the trigone, the anterior horn and the occipital horn, compared to the hemispheres in the axial plane of magnetic resonance imaging (MRI) in neonates. In 44 neonates without any neurological disorders from 26 to 41 weeks of gestational age (GA), MRI was performed between 12 and 124 postnatal days. The mean of the relative size of the ventricle compared to the hemisphere (RSVH) among the subjects showed a significant left-right asymmetry that was observed only in the occipital horn. However, in the body, the anterior horn and the occipital horn, the percentage of neonates with a larger left RSVH compared to the right RSVH was significantly higher than the percentage of neonates with a larger right RSVH compared to the left RSVH. The RSVH of the body and the occipital horn increased according to the number of postnatal days and decreased according to GA. Measuring RSVH was useful in assessing the size of the ventricle in the axial plane of neonatal MRI. It clarified the fact that normative asymmetry, GA of subject, and the number of postnatal days should be considered in assessing the size of ventricle.

Malignant hyperthermia in a patient with Becker muscular dystrophy: dystrophin analysis and caffeine contracture study

We present a 17-year-old boy with Becker muscular dystrophy (BMD) who developed hyperthermia and heart failure after general anesthesia. He presented clinical features of malignant hyperthermia (MH), and had masseter spasm and elevated body temperature (38.7 degrees C) with very high serum CK activity (107,000 IUl-1). Dystrophin tests confirmed a clinical diagnosis of BMD in the patient, i.e. faint and patchy immunostaining pattern of skeletal muscle, truncated dystrophin protein and a deletion of exons 3 and 4 of the dystrophin gene. To inquire into the mechanism of MH associated in the patient, we tested caffeine contracture reaction by the skinned fiber method. We found an increased sensitivity to caffeine only in type 1 muscle fibers. The rate of Ca(2+)-induced Ca2+ release (CICR) was normal, suggesting that the mechanism of "MH" observed in our patient with BMD is not the same as that of classical MH. A possible mechanism might be related to derangements of the sarcoplasmic reticulum membrane in BMD, which sensitize the membrane to caffeine or other agents.

Cloning and mapping of a very short (10-kb) EcoRI fragment associated with facioscapulohumeral muscular dystrophy (FSHD)

Facioscapulohumeral muscular dystrophy (FSHD) is a dominantly inherited muscular disorder and the gene for FSHD has been mapped to chromosome 4q35. Recently, the DNA rearrangements associated with the disease were found in the EcoRI fragment detected by the probes p13E-11 and pFR-1, and deletions of the 3.3-kb KpnI repeat units within the EcoRI fragment are thought to cause the disease. In this study, we cloned the FSHD-associated EcoRI fragments (the shortest fragments identified to date: 10 kb) from 2 severely affected patients (unrelated). Restriction enzyme maps of the genomic fragments in the 2 patients revealed that the 10 kb fragments were identical and contained only one 3.3-kb KpnI repeat unit. These results suggest that deletions of the 3.3-kb KpnI repeat units are likely to associate with FSHD, and that the 10 kb fragments may provide a means of understanding the molecular details involved at the site of the chromosomal rearrangements in FSHD.

Bosentan antagonizes the effects of endothelin-1 on rat gastric blood flow and mucosal integrity

Bosentan, a new type of orally effective, mixed (ETA+ETB) endothelin receptor antagonist has been recently introduced and tested in a variety of experimental models. We studied the effect of bosentan on the changes in gastric mucosal hemodynamics and mucosal integrity, induced by the exogenous application of endothelin-1, in rats. Bosentan (10 mg/kg iv) pretreated rats were injected with endothelin-1 (500-1000-2000 pmol/kg, iv) and gastric mucosal hemodynamics were monitored. After combined oral (30 mg/kg) and systemic pretreatment with bosentan we studied the effects of submucosal injection of endothelin-1 (50 pmol) on blood flow and gastric mucosa. Bosentan antagonized the vasodilator, vasoconstrictor and ulcerogenic effects of endothelin-1 in the rat gastric mucosa. These results show that bosentan can be a useful probe in the study of endogenous endothelin in the gastrointestinal tract.

Human hand impedance characteristics during maintained posture

The present paper examines human hand impedance characteristics, including inertia and viscosity as well as stiffness, in multi-joint arm movements. While a subject maintains a given hand location, small external disturbances are applied to his hand by a manipulandum. The corresponding force-displacement vectors are measured and sampled over time in order to estimate the hand impedance by means of a second-order linear model. The experimental results in different subjects and hand locations are summarized as follows: (1) the estimated inertia matrices of the human hand well agrees with computed values using a two-joint arm model, (2) spatial variations of the stiffness ellipses are consistent with the experimental results of Mussa-Ivaldi et al. (1985), (3) hand stiffness and viscosity increase with the grip force of the subject, and (4) viscosity and stiffness ellipses tend to have similar orientation. The accuracy of the impedance estimation method is validated with a mechanical spring-mass system with known parameters.

Cloning and mapping of a very short (10-kb) EcoRI fragment associated with facioscapulohumeral muscular dystrophy (FSHD)

Facioscapulohumeral muscular dystrophy (FSHD) is a dominantly inherited muscular disorder and the gene for FSHD has been mapped to chromosome 4q35. Recently, the DNA rearrangements associated with the disease were found in the EcoRI fragment detected by the probes p13E-11 and pFR-1, and deletions of the 3.3-kb Kpnl repeat units within the EcoRI fragment are thought to cause the disease. In this study, we cloned the FSHD-associated EcoRI fragments (the shortest fragments identified to date: 10 kb) from 2 severely affected patients (unrelated). Restriction enzyme maps of the genomic fragments in the 2 patients revealed that the 10 kb fragments were identical and contained only one 3.3-kb Kpnl repeat unit. These results suggest that deletions of the 3.3-kb Kpnl repeat units are likely to associate with FSHD, and that the 10 kb fragments may provide a means of understanding the molecular details involved at the site of the chromosomal rearrangements in FSHD.

Characterization of a tandemly repeated 3.3-kb Kpnl unit in the facioscapulohumeral muscular dystrophy (FSHD) gene region on chromosome 4q35

A 3.3-kb Kpnl repeat unit within the tandem repeat locus (D4Z4) and its upstream 2.5-kb Hincll/Kpnl fragment of the facioscapulohumeral muscular dystrophy (FSHD) gene region at 4q35-qter were sequenced and characterized. The 3.3-kb Kpnl unit was 3303 bp in length and contained two homeodomain sequences, one LSau-like sequence, and several microsatellites. The GC content in the 3.3-kb unit was very high (73%), while it was only 35% in the nonrepeated region of the 2.5-kb fragment. We identified 99% homologous sequences (918 bp) in the 3' end of the 3.3- and 2.5-kb fragments. These findings suggested that the repeated sequences at the D4Z4 start from 918 bp upstream to the first Kpnl site.

Interaction between pregnancy-induced bioactive peptides and the placental proteases

Studies have shown that placental proteases metabolize vasoactive peptides, possibly derived from the fetus, and protect the exchange of peptide hormones across the placenta in order to maintain feto-placental homeostasis. Changes in maternal serum protease activities were useful for monitoring pre-eclampsia and predicting the onset of labour. The study showed that possible role of oxytocinase in the maintenance of gestation and the possible involvement of angiotensinase in the attenuated pressor responses to angiotensin II during pregnancy, respectively. In addition, the ratio of peak systolic over least diastolic pressure (S/D) of uterine or umbilical artery assessed by the Doppler technique was closely correlated with the concentrations of maternal serum proteases in pre-eclampsia, which suggested that placental proteases might control utero-placental circulation via the regulation of concentrations of vasoactive peptides in uteroplacental circulation.

Inflammatory response in facioscapulohumeral muscular dystrophy (FSHD): immunocytochemical and genetic analyses

To investigate the nature of the inflammatory response in facioscapulohumeral muscular dystrophy (FSHD), we analyzed mononuclear cells in muscle sections obtained from 18 FSHD patients and 8 controls. Monoclonal antibodies reactive for T cells, T cell subsets, B cells, and NK cells were used for cell typing. Macrophages were identified by acid phosphatase reaction. The localization of perforin, granzyme A, MHC-I and -II, dystrophin, and alpha-actinin antigens was also examined. We found that all FSHD patients, both familiar and sporadic cases, had greater amounts of mononuclear cellular infiltrates in muscle than controls, in whose specimens only few extra vascular mononuclear cells were counted. Seventy-two percent (13 of 18) of the patients had more than 50 inflammatory mononuclear cells per 1000 muscle fibers, and 33% (6 of 18) patients had numerous inflammatory cells exceeding 600 per 1000 muscle fibers (1835 +/- 482 SE). Nonnecrotic fibers invaded by mononuclear cells with either T8+, perforin+, or granzyme A+ were not observed in FSHD, while a few degenerating fibers were superficially invaded by T cells and macrophages. Occasional T cells were observed moving through the blood vessel wall. The increased number of necrotic fibers was paralleled by an increased number of inflammatory cells (r = 0.783, P = 0.0001). Genetic analysis, using the probes p13E11, pFR-1, D4S139, and D4S163, was done in 6 patients (3 familiar, 3 sporadic) who had numerous inflammatory infiltrates. These 6 patients had small (<28 kb) EcoRI fragments associated with the disease, and the disease was linked to 4q35. These results suggest that, in chromosome 4-linked FSHD: (1) inflammatory changes in muscle are a common histological feature; (2) mononuclear cellular infiltrates may enhance muscle fiber damage; but (3) T-cell-mediated cytotoxicity directed against muscle fibers is unlikely. We speculate that the immune effector mechanism in FSHD is different from that in previously reported inflammatory myopathies and Duchenne muscular dystrophy.

Cloning and expression of a cytoskeleton-associated diacylglycerol kinase that is dominantly expressed in cerebellum

A third species of diacylglycerol kinase (EC 2.7.1.107) cDNA was cloned from a rat brain cDNA library. The isolated cDNA encoded a 788-amino acid, 88-kDa polypeptide. This isozyme shared 58% identity with the previously isolated rat 80-kDa and 90-kDa diacylglycerol kinases. EF hand motifs, cysteine-rich zinc finger-like sequences, and putative ATP-binding site were all conserved among these isozymes. The 88-kDa diacylglycerol kinase was expressed specifically in brain and localized predominantly in cerebellar Purkinje cells. This isozyme was associated equally with particulate and supernatant fractions in cDNA-transfected COS-7 cells and dominantly with the particulate fraction in the brain. After Triton X-100 extraction, this isozyme remained in the detergent-insoluble cytoskeletal fraction of the brain and transfected COS-7 cells.

[A case of carcinomatous meningitis from transitional cell carcinoma of the urinary bladder]

We report a case of carcinomatous meningitis from transitional cell carcinoma of the urinary bladder. A 70-year-old man with invasive bladder cancer and multiple pulmonary metastases received 3 courses of systemic M-VAC (methotrexate, vinblastine, doxorubicin, and cisplatin) chemotherapy, after which the primary tumor and pulmonary metastases diminished in size and number. During the 4th course of chemotherapy, he complained of nausea, headache, diplopia, and neck stiffness. Computer tomographic (CT) scan of the brain showed no evidence of parenchymal metastases, cerebral hemorrhage, or infarction. Cerebrospinal fluid examination revealed an increase in cells along with elevated protein and depressed glucose concentrations, but no malignant cells were identified. He died two weeks after the onset of neurological symptoms. Autopsy revealed numerous tiny metastatic lesions in the leptomeninx, so called carcinomatous meningitis, without parenchymal metastases in the brain. Although metastases to the central nervous system from transitional cell carcinoma of the bladder, especially carcinomatous meningitis rarely have been reported, this unusual complication will be seen more frequently with the development of more effective systemic chemotherapy such as M-VAC.

Endothelin-1 activates mitogen-activated protein kinases through two independent signalling pathways in rat astrocytes

Northern blot analysis and displacement study revealed that the endothelin (ET) receptor functionally expressed in rat primary cultured astrocytes is the ETB receptor. Mitogen-activated protein kinases (MAP kinases) in the cells were activated by 10 nM ET-1, a dose that maximally stimulated phosphoinositide hydrolysis. This activation was potently inhibited by pretreatment of the cells with phorbol 12-myristate 13-acetate (PMA) which leads to protein kinase C (PKC) down-regulation and was slightly inhibited by pretreatment with pertussis toxin (PTX). Pretreatment of the cells with PMA plus PTX completely inhibited the ET-1-augmented MAP kinase activity. Activation of MAP kinases was also induced by 0.1 nM ET-1, which hardly stimulated phosphoinositide hydrolysis. This activation was fully inhibited by pretreatment with PTX but insensitive to pretreatment with PMA. ET-1-stimulated production of inositol phosphates was not affected by pretreatment with PTX. These results suggest that activation of MAP kinases secondary to stimulation of the ETB receptor with ET-1 in rat primary cultured astrocytes was mediated through two independent signalling pathways. PKC-dependent pathway and PTX-sensitive G protein-mediated pathway.

[A case of facioscapulohumeral muscular atrophy presenting unusual squatting gait, associated with tongue atrophy and sensorineural hearing loss]

A 16-year-old girl has presented speaking disturbance since early in life. Difficulty in running was noted at the age of 7. Her mother (46 years old) had moderate facial weakness and mild proximal weakness of the upper and lower limbs. Neurological examination at age 9 revealed bilateral facial weakness, tongue atrophy and weakness of the shoulder girdle, upper arms, and thighs. Deep tendon reflexes were absent in the four limbs. Gait was waddling. Over the next several years, she developed wasting and weakness around the shoulder girdle, upper arms, thighs, and increased lordosis. She lost the ability to walk by age 13. Since then, she has moved with difficulty in a squatting position. Serum CK was moderately increased and needle EMG in the extremities revealed myopathic changes. Muscle CT demonstrated marked atrophy of the proximal muscles in the left arm and lower limbs and mild atrophy of the calves. Audiogram showed bilateral mild sensorineural hearing loss. Muscle biopsy of the quadriceps at age 9 showed nondiagnostic findings. This case could be diagnosed as congenital facioscapulohumeral muscular dystrophy. Tongue atrophy and sensorineural hearing loss are rarely associated with this syndrome, as well as unusual squatting gait.

The on-off mechanisms of the nicotinic acetylcholine receptor ion channel are performed by thermodynamic forces

The active sites of nicotinic acetylcholine receptors are comparatively strong hydrophobic areas. When nicotinic acetylcholine receptor alpha-subunits bind with acetylcholines, the polar groups of nicotinic acetylcholine receptors and acetylcholines become more hydrophobic owing to repulsion of the bound water molecules, and the charged groups of nicotinic acetylcholine receptors and acetylcholines are neutralized. Thus, the large hydrophobic areas form at and around the binding sites of nicotinic acetylcholine receptors and acetylcholines. These exposed hydrophobic areas are unstable thermodynamically (oil in water), and thus sink toward the neighboring hydrophobic transmembrane segment (M2). The sinking of the acetylcholine-binding sites with the M2, which contains an ion channel, causes the negative residues of the top of the M2 to descend to the hydrophilic level of the immobile M2 of the other nicotinic acetylcholine receptor subunits. This pathway, which consists of hydrophilic part of the sunken alpha-subunits and the hydrophilic part of the immobile M2 of other subunits, allows for the easy passage of cations across the cellular membrane. The movements of the alpha-subunits sinking to the transmembrane area cause the release of acetylcholines from binding sites. The hydrophilic groups of acetylcholines (quaternary ammonium ion, etc) and nicotinic acetylcholine receptors (ionic groups of M2, etc) are unstable in hydrophobic conditions (water in oil), resulting in the binding site and the hydrophilic residues of M2 returning to the positions in the resting state.(ABSTRACT TRUNCATED AT 250 WORDS)