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Biomedical subjects

T Okuno

Publications and source records attributed to T Okuno.

At least 181 records · Page 10Linked to original sources
PubMed1992

Nucleotide sequence responsible for the synthesis of a truncated coat protein of brome mosaic virus strain ATCC66.

The ATCC66 strain of brome mosaic virus (BMV) (propagated at Kyoto University) contained two types of coat protein in its virion whereas the Russian strain of BMV has been known to contain a single coat protein; both strains have two initiation codons for coat protein in the same reading frame at the 5'-proximal end of the gene in RNA 4. Comparative studies on the nucleotide sequences of the ATCC66 and Russian strains of BMV demonstrated that in the ATCC66 strain, two adjacent adenine residues were absent from RNA 3 in the leader sequences of the coat protein gene just a few nucleotides 5' to the first initiation codon of the coat protein gene. Using biologically active cDNA clones of BMV RNA of the ATCC66 strain, we inserted two adjacent adenine residues into the cDNA of RNA 3 to obtain an RNA 3 transcript which has the same nucleotide sequence as the Russian strain in the non-coding leader sequence of the coat protein gene. Barley protoplasts inoculated with this RNA 3 transcript together with RNA 1 and 2 produced a single coat protein. To obtain further insight into the mechanism of translation of the BMV coat protein, we constructed several types of RNA 4 by changing the sequence surrounding the first AUG codon in the coat protein gene and analysed the in vitro translation products of the mutant RNA 4. The results confirmed that the absence of the two adjacent adenine residues was responsible for the production of two types of coat protein in the ATCC66 strain. The deletion of the two adjacent adenine residues in ATCC66 resulted in a base substitution of A with U three nucleotides 5' to the first AUG in the coat protein gene. The base substitution reduced translational activity from the first AUG codon and concomitantly increased translational activity from the second AUG codon from which a truncated coat protein was translated.

Capsid↗
PubMed1992

Analysis of human herpesvirus 6 glycoproteins recognized by monoclonal antibody OHV1.

A virus-specific glycoprotein (gp) from human herpes-virus 6 (HHV-6) was studied using the anti-HHV-6 monoclonal antibody OHV1. Immunoprecipitation with extracts from infected cells revealed that the antibody recognized four glycosylated proteins (gps) with Mrs of 106K, 102K, 65K and 63K under reducing conditions. However, only two gps, of 106K (gp106) and 102K, were detected under non-reducing conditions. Pulse-chase experiments revealed that gp65 and gp63 were cleavage products of gp106 and gp102. When infected cells were treated with tunicamycin, none of these gps was detected. With endo-beta-N-acetylglucosaminidase H (endo H) and endo-beta-N-acetylglucosaminidase F (endo F) treatment, gp106 and gp102 disappeared. Moreover, gp65 and gp63 were not affected by endo H treatment but were sensitive to endo F treatment. These data suggest that sugar residues of gp106 and gp102 are high-mannose type N-linked oligosaccharides, whereas those of gp65 and gp63 are complex type N-linked oligosaccharides.

Antibodies, Monoclonal↗
PubMed1992

Processing of hepatitis B virus surface antigen expressed by recombinant Oka varicella vaccine virus.

We have constructed a recombinant Oka varicella vaccine virus expressing hepatitis B virus (HBV) surface antigen (HBsAg). HBsAg was synthesized as 26K and 30K proteins in infected cells and secreted into the culture supernatant as 30K and 35K proteins. Inhibitors and glycosidase treatments, and pulse-chase labelling experiments, revealed the glycosylation process of HBsAg. The latter was synthesized as a non-glycosylated 26K protein and subjected to N-linked glycosylation to form a 30K protein with high mannose glycans. Three species of dimers composed of 26K and 30K subunits were then formed with disulphide bonds. Both subunits of the dimers were further subjected to O-linked glycosylation and conversion from high mannose glycans to complex glycans followed by sialylation. Three species of dimers composed of 30K and 35K subunits were secreted into the culture supernatant as HBsAg particles. HBsAg was synthesized, glycosylated with both N- and O-linked glycans, sialylated, and then secreted into the culture supernatant within 1 h. These modifications of HBsAg by glycans might stabilize its structure and enhance its immunogenicity as a live HBV vaccine.

Electrophoresis, Polyacrylamide Gel↗
PubMed1992

Human herpesvirus 6 (HHV-6) infection in the central nervous system.

Human herpesvirus 6 (HHV 6) was isolated from patients with exanthema subitum (ES) with a high frequency, and it is now believed that this virus causes ES as a primary infection in childhood. HHV 6 infection is highly prevalent in early childhood and this virus may infect infants through the saliva mainly from mother to child. HHV 6 has a tropism to CD4+ cells and destroys cells in vitro. Although children recover from ES without any sequelae, neurological symptoms associated with exanthema subitum are often observed, and we could detect HHV 6 in the cerebrospinal fluid of ES patients. This result suggests that HHV 6 may invade the central nervous system and cause neurological symptoms.

Antibodies, Viral↗
PubMed1992

Continuous, generalized, high-voltage fast activity and FIRDA in two children.

The EEG pattern of continuous, generalized, high-voltage fast rhythms without any reaction to eye-opening/closure, photic stimulation, or the sleep-awaking cycle was previously reported to be characteristic of infantile neuroaxonal dystrophy (INAD). However, we have observed such fast activity in one child with INAD and one with Menkes' kinky-hair syndrome. They both exhibited severe psychomotor disturbance, and their EEGs also included "frontal intermittent rhythmic delta activity (FIRDA)," a nonspecific EEG finding suggestive of organic encephalopathy. Since the continuous, generalized, high-voltage fast activity had features suggestive of spindles in both children, this EEG pattern is thought to actually represent "extreme spindles," and nonspecifically to indicate widespread organic brain damage.

Cerebral Cortex↗
PubMed1992

Changes in blood volume and potassium concentration during exercise in rats.

We measured the changes in circulating blood volume (BV), plasma sodium ([Na+]), and plasma potassium ([K+]) concentrations continuously, during and after exercise in euhydrated and dehydrated rats. Rats ran on a treadmill for 15 min at 600, 900, and 1,200 m/h, and the recovery period lasted 45 min. The BV decreased immediately after onset of exercise, and reached a plateau value in about 5 min of exercise. With 1,200 m/h exercise, a further decrease in blood volume was observed in both groups. The decline in BV was reversely related to the exercise intensity in both groups although the decrease was less in the dehydration group. During and after exercise, there were no significant changes in plasma [Na+] at any speed in either group. Plasma [K+] increased sharply at the onset of exercise and the magnitude of the increase was directly related to the exercise intensity. However, at all three exercise intensities the change in plasma [K+] in the dehydrated group was only about 60% of that measured in the euhydrated control group. These findings suggest that dehydration reduces the wash-out of K+ from the interstitial space of the exercising muscle.

Analysis of Variance↗
PubMed1992

Anomalous multifocal ossification of the os calcis--case report.

A three-month-old female baby was diagnosed by roentgenograms as having bilateral multifocal ossification of the os calcis. Five ossification centers in the bilateral calcaneus were recognized. However, at one year of age the roentgenograms showed only three ossification centers, with cleft separating on both sides the anterior third from the posterior two-thirds of the bone. At two years of age, the three ossification centers had coalesced into a single composite ossification center and the cleft at the calcaneus disappeared.

Calcaneus↗
PubMed1992

[A case of Noonan syndrome with neurogenic bladder].

We report a case of Noonan syndrome with neurogenic bladder. The patient was a 33-year-old man with a chief complaint of difficulty in urination, urinary frequency, and incontinence of urine. He had also various malformations, as deformities of the face, skull and hard palate, webbed neck, nail abnormality, edema of the lower extremities, contraction of visual field, deafness, malrotation of the intestine and so on. The case was diagnosed as Noonan syndrome because his karyotype of chromosome was 46, XY. Malformations of the urogenital organs were mild malrotation of bilateral kidneys, a right renal cyst, left cryptorchidism and pseudo phimosis. The uroflowmetrogram of the case showed a saw-like and flat pattern, with urination starting by tapping lower abdomen by himself. The cystometry and electromyogram of the external sphincter revealed neurogenic bladder with uninhibited contraction and detrusor-external sphincter dyssynergia. This is the first case of Noonan syndrome with neurogenic bladder.

Adult↗
PubMed1992

[Relationship between bladder trigone and bladder neck induced by traction of an indwelling balloon catheter with a spring balance and parameters of cystometrogram].

Sensation of the bladder trigone and bladder neck induced by traction of an indwelling balloon catheter with a spring balance and cystometry was evaluated in 393 males and 106 females. Male patients with an average age of 56.9 +/- 15.9 (mean +/- standard deviation) years old (range 17 to 88 years) were divided into 7 groups as follows: 19 patients without any micturitional disturbance, uregency and chronic prostatitis (11 patients), benign prostate hypertrophy (BPH) (131 patients), cervical or thoracic cord compression disorders (67 patients), lumbar vertebral disorders (114 patients), other peripheral nerve disorders associated with diabetes mellitus, post operative status of rectum cancer and others (27 patients) and brain diseases (24 patients). Female patients with an average age of 55.2 +/- 15.5 years old (range 17 to 88 years) were divided into 6 groups as follows: 24 patients without any neurological problems, urgency (7 patients), cervical or thoracic cord compression disorders (11 patients), lumbar vertebral disorders (37 patients), other peripheral nerve disorders (18 patients) and brain diseases (9 patients). The observed sensation, first desire to void (FDV) and maximum cystometric capacity (MCC) were evaluated statistically in relation to clinical factors (e.g. disease group, generation and patterns of cystometrogram). The correlation between the sensation and FDV or MCC in these patients were assessed by linear regression analysis. Sensation of normal males was 334.2 +/- 159.7 g on the average and correlated well with FDV (r = 0.88, y = 375x - 189.4). Sensation of normal females was 373.3 +/- 199.5 g on the average. However, there was no correlation (r = 0.35) between sensation and FDV in females. In males, the means of sensation obtained in patients with other peripheral nerve disorders (557.3 +/- 314.5 g) was significantly larger than the means of normal subjects (p less than 0.001), and patients with uregency and chronic prostatitis (236.4 +/- 148.3 g, p less than 0.01), BPH (424.1 +/- 215.6 g, p less than 0.001), cervical or thoracic cord compression disorders (349.0 +/- 229.5 g p less than 0.001), lumbar vertebral disorders (349.7 +/- 201.7 g, p less than 0.001) or brain diseases (490.6 +/- 305.0 g, p less than 0.05). Furthermore, the differences in the means of sensation between BPH and lumbar vertebral disorders (p less than 0.05) or brain diseases (p less than 0.05) were statistically significant.(ABSTRACT TRUNCATED AT 400 WORDS)

Catheterization↗
PubMed1992

[A case report of multiple pulmonary tumors as a sole manifestation of synovial sarcoma].

A 47-year-old woman was admitted to our hospital for cough and dyspnea. Roentgenologic studies and bronchoscopy revealed multiple lung tumors one of which obstructed the right main bronchus. Right pneumonectomy was performed for the pending obstruction of the trachea. The tumor in the right S1 was found to be protruding into the trachea through the right B1 and the main bronchus in a polypoid fashion. The pathological diagnosis of synovial sarcoma was made on the basis of the characteristic biphasic structure composed of spindle cells and epithelioid cells forming gland-like spaces. Three years and eight months after the pneumonectomy, a nodule in the tendon of the extensor hallucis longus muscle became palpable. It was also a synovial sarcoma pathologically. Synovial sarcoma is a soft tissue sarcoma which usually arises in the extremities. It is very rare for pulmonary metastasis of this tumor to be found while the primary tumor is undetectable.

Female↗
PubMed1992

[Preoperative diagnosis of internal mammary node metastases in patients with breast cancer by using ultrasonography].

US findings of 81 patients with breast cancer were analyzed respectively to evaluate the usefulness of US in the preoperative diagnosis of internal mammary mode metastases. The internal mammary area (I.M.A.) in which internal mammary nodes lie was shown as a hypoechoic stripe in a sagittal scan along the sternum and as a triangular or spindle-shaped hypoechoic area in a transverse scan in the intercostal space. The US features of each I.M.A. in the first three intercostal spaces were divided into three patterns: Pattern-A wad defined as widening of the ipsilateral side of the I.M.A. compared with the contralateral side; Pattern-C was defined as normal at both sides of the I.M.A. Pathological examination confirmed the node metastases in 85.7% of intercostal scans showing Pattern-A and in 35% of intercostal scans showing Pattern-B. Only one of 189 intercostal scans showing Pattern-C had nodal metastases. The overall accuracy was 88.1% in 243 intercostal scans and 90.1% in 81 patients. We conclude that US is useful in the detection of internal mammary node metastases in patients with breast cancer.

Breast↗
PubMed1992

[Methicillin-resistant Staphylococcus aureus (MRSA) isolated in hospitals in Fukuoka City area].

Bacteriological and clinical studies were carried out on 280 strains of Staphylococcus aureus isolated in hospitals in Fukuoka city area from September 1990 to March 1991. Of all S. aureus strains studied 116 (41.4%) were methicillin-resistant. The proportion of MRSA in S. aureus isolates from outpatients was 10% (11/109), 69.2% (90/130) in those from inpatients. The average age of patients with isolated MRSA was 70.5 +/- 16.9 years and that of patients with isolated MSSA, 44.2 +/- 29.3. MRSA strains were recovered mainly from sputum and pus. The isolation rate did not vary significantly with hospitals of different size (number of beds). Of all MRSA strains 48 (41.3%) produced coagulase type VII. As for drug susceptibility, MRSA strains with coagulase type VII were more sensitive to clindamycin and more resistant to minocyclin compared to MRSA with other coagulase types.

Age Factors↗
PubMed1992

[A case of transitional cell carcinoma of renal pelvis with an extremely high serum carcinoembryonic antigen (CEA) level].

A case of urothelial tumor with extremely high serum carcinoembryonic antigen (CEA) levels is described. A 68-year-old female presented with macroscopic hematuria and left flank pain. Laboratory examination revealed an extremely high serum level of CEA (194 ng/ml) and elevated levels of serum CA 19-9 (235 U/ml) and squamous cell carcinoma (SCC)-Antigen (10.7 ng/ml), while urine CEA remained within normal limits. No abnormal findings were recognized in gastrointestinal and respiratory systems, but left renal pelvic tumor (T4N2M0) was discovered. Nephroureterectomy with regional lymph node dissection was done. The pathologic anatomy was infiltrating non-papillary transitional cell carcinoma (TCC, G2 = G3, pT4N2M0). More than 30% of the tumor cells were positive for CEA by ABC-peroxidase staining. Levels of tumor markers remained higher than normal after the operation and were normalized after M-VAC (methotrexate, vinblastine, adriamycin and cisplatin) chemotherapy. However, 6 months after the operation, levels of tumor markers rose again and lung metastases appeared. She died 10 months after the operation.

Aged↗
PubMed1992

Inner ear morphology of experimental perilymphatic fistula.

The inner ear pathology of experimental perilymphatic fistula (EPLF) is described. EPLF was produced by injecting artificial perilymph into the subarachnoid space, or by suctioning 4 microL of perilymph through one of the round window membranes of the guinea pig. The animals were either killed immediately, or were kept alive for 3 weeks to 3 months. The conventional celloidin embedding method was employed for morphologic study. Vestibular function of the animals was tested by observing spontaneous nystagmus and positional nystagmus after the experiment. The caloric test was also performed. Various pathologic changes of the membranous labyrinth were observed. In the cochlea these included rupture or collapse of Reissner's membrane, bulging of Reissner's membrane, loss of hair cells, and compression of the organ of Corti. Pathology of the otolithic organs and semicircular canals mainly consisted of collapse of the membranous labyrinth. Clinical symptoms in patients with perilymphatic fistula (PLF) are explained, based on our experimental findings. Electronystagmography (ENG) of EPLF animals showed either no caloric response or, with a longer duration, caloric irregularity. Prolonged unsteadiness in patients may be due to "floating" labyrinth.

Animals↗
PubMed1991

Antibody response to the immediate early protein of cytomegalovirus in renal transplant recipients.

The antibody response to the immediate early protein (IEP) of cytomegalovirus (CMV) was examined in seven renal transplant recipients during CMV reactivation and associated clinical abnormalities. Three cases with antibody increase to the IEP in the week after CMV isolation had no CMV-induced disease. The four patients without antibody increase exhibited laboratory abnormalities and three of them had renal dysfunction. In this small number of patients, the antibody response to the IEP in the week after isolation of CMV was associated with absence of abnormal clinical laboratory findings including renal function, and the prognosis was good for graft function in renal transplant recipients with CMV reactivation.

Antibodies, Viral↗