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Biomedical subjects

T Ohsawa

Publications and source records attributed to T Ohsawa.

At least 19 recordsLinked to original sources
PubMed1992

Obliteration of the descending aortic interface in pectus excavatum: correlation with clockwise rotation of the heart.

Obliteration of the descending aortic interface is a new radiographic finding in pectus excavatum. Seventy frontal and lateral chest radiographs and 33 computed tomographic (CT) scans of patients with pectus excavatum were retrospectively reviewed to evaluate the frequency, possible cause, and clinical significance of this finding, which was detected in 21 of 70 cases (30%) of pectus excavatum. No significant relationship was found between this finding and the extent of the thoracic deformity. In patients with this finding, the left inferior pulmonary vein (PV) entered the left atrium at an acute angle to the sagittal plane, as demonstrated at CT, and this angle was significantly smaller than that in patients without this finding. The PV angle also significantly correlated with the cardiac rotation angle. In pectus excavatum, partial obliteration of the descending aortic interface can be mistaken for adjacent disease.

Adult↗
PubMed1992

Laser diffraction estimation of particle size distribution of slightly water-soluble drugs coexisting with additives: application to solid dosage forms.

A simple and quantitative evaluation method for particle size distribution (fx(r)) of slightly water-soluble drugs dispersed in an aqueous medium together with other water-insoluble additives was developed using a laser diffraction method. The particle size distribution function of the powder mixture, (f(r)), was assumed as f(r) = phi x.fx(r) + phi a.fa(r), where phi is the volume fraction of each component dispersed in a measurement medium and fa(r) is the distribution function of another water-insoluble additive "a". In order to calculate fx(r) from f(r), it is necessary to know the density of drug and additive in the measurement medium, d(x) and d(a), but this is difficult to determine since particles usually swell in the medium. Thus, a method was developed to use their relative value, delta a (= da/dx). As a practical application, oxolinic acids (OA) of three sizes (OA-S (about 2 microns), OA-M (about 7 microns) and OA-L (about 24 microns)) were used as model drugs. delta a values were determined for various additives using the mixture of OA-S and each additive. Then, using delta as, fx(r) of OA-M or OA-L in the mixture containing OA-M or OA-L and additives was calculated from the f(r) experimentally determined for the mixture. They agreed well with their original distributions. The method was applied to some dosage forms, and the results obtained had good correlation with those from turbidity, wet sieving or dissolution test.

Algorithms↗
PubMed1991

Age-related alteration of brain gangliosides in senescence-accelerated mouse (SAM)-P/8.

The senescence-accelerated mouse (SAM)-P/8 was examined with respect to changes in the content and composition of brain gangliosides during aging from juvenile to senescence. The gangliosides were compared with those of control mice, senescence-accelerated resistant mouse (SAM)-R/1. The ganglioside contents in the whole brains of SAM-P/8 and -R/1 were at almost constant level from 0.5 to 6 months, but decreased thereafter until senescence to about 80% of the levels reached at the younger ages. Upon aging, the ganglioside compositions changed with an increase of GM1, and decreases of GD1a, GD1b and GT1b in both strains (GT1b greater than GD1a greater than GD1b). A minor component, GM3 was two to four fold higher in the molecular distributions of the whole brain gangliosides of SAM-P/8 than those of -R/1 at any age examined throughout the life span. The regional gangliosides in olfactory bulb, cerebral cortex, hippocampus, hypothalamus, cerebellum, corpora quadrigemina region, brain stem and medulla oblongata were compared between the two strains at the age of three months. The ganglioside contents in the brain stem and medulla oblongata were lower in SAM-P/8 than -R/1, but there was no significant difference between the two strains in the other regions. As a minor component, GM3 was found to occur in a higher concentration in SAM-P/8 than -R/1 in all brain regions examined, except in the olfactory bulb where GM3 was detected as a major component with no difference in the distribution level between the two strains.

Aging↗
PubMed1990

[MR imaging of the carpal tunnel syndrome].

Magnetic resonance (MR) imaging of the carpal tunnel was performed in 23 wrists of 13 patients who were suspected to have carpal tunnel syndrome (CTS). In ten out of 23 wrists, diagnostic images of the carpal tunnel could be obtained. MR images were analysed retrospectively as to swelling of the median nerve, signal intensity of the median nerve on T2 weighted image, and swelling of the tendon sheath. In 8 wrists the median nerve was significantly swollen at the inlet of the carpal tunnel. Four of them showed increased signal intensity of the median nerve on T2 weighed image at the inlet. Swelling of the tendon sheath was demonstrated in two cases. These finding seem to represent edematous change of the median nerve due to compression. Surgical correlation was obtained in two wrists. Since MR imaging is capable of demonstrating pathological changes of the median nerve in CTS, it can be a diagnostic tool in selected cases.

Adult↗
PubMed1990

Rat dorsal root ganglion gangliosides during early development until senescence.

The gangliosides of male rat dorsal root ganglia were studied during aging from the first day postnatally until senescence at 24 months. The ganglioside contents increased drastically until 12 months after birth and thereafter did not change considerably, and the increase pattern was in parallel with the increase of wet weight of the tissues. The major gangliosides of the dorsal root ganglia were GM3, LM1 (sialosyl-lactoneotetraosylceramide), unknown ganglioside X, GD1a, GD1b, GT1b and GQ1b. The most drastic changes in ganglioside composition were observed between the ages of postnatal day 1 and 1.5 months. The unknown ganglioside X (dominant at postnatal day I) decreased up to 1.5 months. In contrast, LM1, a minor ganglioside postnatal day 1, increased until 1.5 months of age. Except for these changes, the other gangliosides were present at almost constant ratios in the component profiles during aging until senescence.

Aging↗
PubMed1990

Prosthetic treatment for speech disorders due to surgically acquired maxillary defects.

To evaluate speech following prosthetic obturation of surgically acquired maxillary defects, the speech intelligibility of eight patients was measured preoperatively and postoperatively, with and without prostheses. Oro-nasal separation and velopharyngeal function were also evaluated by use of a specially designed spirometer and endoscope. Following placement of maxillary obturator prostheses, four patients achieved dramatic improvement in speech intelligibility, while four patients did not. In the latter, insufficient improvement in speech intelligibility was attributed to velopharyngeal incompetence or unstable prosthesis. Two of three patients with velopharyngeal incompetence did achieve adequate improvement in speech following placement of a speech appliance in combination with maxillary obturator prostheses.

Adult↗
PubMed1990

[High-resolution CT in evaluation of temporal bone trauma].

High-resolution CT (HRCT) examinations were performed in 22 patients with temporal bone trauma. The CT findings were correlated with the clinical signs and symptoms, routine head CT findings were also examined. HRCT was able to demonstrate fracture lines, ossicular chain disruptions, facial nerve injuries, and hemotympanums in majority of cases. Associated many severe head injuries (brain contusion etc.) were noted in the routine head CT.

Adolescent↗
PubMed1989

Lack of modifying effects of linolic acid hydroperoxides and their secondary oxidative products on combined 7,12-dimethylbenz[a]anthracene and 1,2-dimethylhydrazine-initiated mammary gland, ear duct and colon carcinogenesis in female Sprague-Dawley rats.

Effects of hydroperoxides, autoxidation products of linolic acid (HPO) and secondary oxidative products of HPO (SOP) (5% each in diet) were examined in female Sprague-Dawley rats. HPO and SOP administration was carried out during or subsequent to two injections of dimethylhydrazine (DMH) (40 mg/kg body wt s.c.), and a single i.g. dose of 7,12-dimethylbenz[a]anthracene (DMBA) (50 mg/kg body wt). No significant differences in the incidences of tumors in the mammary gland, colon, ear duct and hematopoietic system associated with HPO or SOP treatment were evident, during or after carcinogen exposure. The present results therefore indicate that the environmental contaminants, HPO and SOP, lack any potential for modification of mammary gland or colon carcinogenesis under the conditions of the investigation.

1,2-Dimethylhydrazine↗
PubMed1989

[MR imaging of femoral head avascular necrosis with STIR sequence].

The uncomplicated bone necrosis is usually demarcated by reactive interface (RI). To analyze signal characteristics of RI, MR imaging of the hip was done using short TI IR (STIR) as well as short/long TR pulse sequences at 0.22 tesla. On STIR sequence the RI was observed as a high-signal line or ring with the shape identical to that of short TR image. The double line sign was not seen in early stage. The best explanation of high signal intensity of RI on STIR is that it has prolonged T1 and T2 secondary to high water content. It is concluded that STIR is an unique way to demonstrate RI in early osteonecrosis.

Adult↗
PubMed1989

Prometaphase chromosomes in the tricho-rhino-phalangeal syndrome type I.

Prometaphase chromosome analysis was undertaken in a patient with familial tricho-rhino-phalangeal syndrome type I (TRPS-I). The patient had apparently normal chromosomes and produced counterevidence to part of Bühler's hypothesis. Thus, although some cases of typical TRPS-I may be derived from a deletion of 8q24.12, others might be caused by gene mutation or submicroscopic deletion involving the corresponding locus within the band 8q24.11----24.13.

Abnormalities, Multiple↗
PubMed1989

Immunotherapy using Freund's adjuvant and recombinant interleukin-2 combined with transarterial chemoembolization for hepatocellular carcinoma.

A new immunotherapy for hepatocellular carcinoma (HCC) using Freund's adjuvant and recombinant interleukin-2 (IL-2) combined with conventional transarterial chemoembolization therapy was performed. In 16 patients with HCC and one patient with metastatic liver cancer receiving this therapy, decrease and suppression of reelevation of alpha-fetoprotein after therapy was observed. Disappearance of tumor thrombi of HCC in the main portal vein was observed in a patient, and decrease of carcinoembryonic antigen was also observed in a patient with metastatic liver cancer. The present therapy using Freund's adjuvant and IL-2 is likely to open a new avenue for the treatment of patients with advanced liver cancer.

Aclarubicin↗
PubMed1989

Expression of tumor necrosis factor at a specific developmental stage of mouse embryos.

We investigated the expression of the tumor necrosis factor (TNF) gene during development of mouse embryos, and observed its transient expression on Days 9 and 10 of gestation. We also detected a 25-kDa protein showing immunological cross-reactivity with mouse TNF antibody in an extract of 10-day embryos. These results suggest that TNF plays a role in mammalian ontogenesis.

Animals↗
PubMed1989

Changes of mouse brain gangliosides during aging from young adult until senescence.

The brain gangliosides from young adult to senescent mice (BDF1 and C57BL/6) were studied. The total ganglioside concentrations of the whole brains were almost constant from young adulthood until the beginning of senescence, but decreased constant from young adulthood until the beginning of senescence, but decreased during senescence to about 80% of the constant level observed at the period before the beginning of senescence. In spite of the constancy of the ganglioside concentrations at the period before the beginning of senescence, the composition gradually changed, with an increase of GM1 and decreases of GD1b, GT1b and GQ1b. During the senescence, all of the gangliosides decreased in their concentrations, but GD1a, GT1b and GQ1b decreased to a markedly greater extent (GT1b greater than GD1a greater than GQ1b). The regional gangliosides in olfactory bulb, cerebrum cortex, cerebrum white matter, hippocampus, hypothalamus, cerebellum and medulla oblongata were compared between 3- and 30-month-old mice of both strains. Significant changes in ganglioside concentrations were observed in both strains in the cerebrum and the hippocampus. In the cerebrum white matter, cerebellum and medulla oblongata, GM1 and GM4 contents significantly increased in the senescent mice.

Aging↗
PubMed1989

Age and cell density dependent changes of gangliosides in human diploid fibroblasts.

The gangliosides in human diploid fibroblasts--TIG-1, TIG-7, and IMR-90--were analysed at different cell densities at early and late passages to clarify the relationship between age and cell density dependent changes of the gangliosides. In early passages, the ganglioside concentrations increased with increase in cell density. At late passages, however, the concentrations were lower than those at the early passages either in the growing or confluent phase, and slightly increased with increase in cell density. The pattern of ganglioside compositions were apparently different between early and late passage cells either in growing or confluent state. In the early passages, GM3 and GD3 were major constituents, and GM2, GD1a, or the other more complex gangliosides were detected as minor components. With increase in cell density, the content of GM3 decreased, whereas GD3 and the others increased. At the late passages, however, GM3 was the major component, and GD3, GM2, or GD1a were minor, but the others were hardly detectable. The ganglioside pattern did not change with increase in cell density. Thus, the age-dependent changes of gangliosides could be distinguished from the cell density dependent alterations.

Cell Count↗
PubMed1989

Follow-up study of atlanto-axial instability in Down's syndrome without separate odontoid process.

Clinical and roentgenologic studies were performed in 69 children with Down's syndrome, without the separate odontoid process, that could be followed for more than 5 years. At the follow-up examination, the atlanto-odontoid process interval (AOI) in flexion, neutral, and extension of the cervical vertebrae significantly decreased when compared with the one at the initial examination. This was particularly obvious up to 5 years of age. Although 14 of 69 cases (20.3%) had atlanto-axial instability at the initial examination, this decreased to four cases (5.8%) at the follow-up examination. However, there were two cases of atlanto-axial instability who were over 10 years of age. There was no significant difference in the minimum sagittal diameter (MSD) at the atlantal level between each position at both the initial and follow-up examinations. Moreover, there was a tendency for the MSD of the cases of positive instability at the follow-up examination to be smaller than those of the cases of negative instability. The degree of ligament laxity improved with increasing age and there was statistically the negative correlation. Although there was a tendency for the AOI to decrease with improvement of the degree of ligament laxity, the correlation could not be confirmed.

Aging↗
PubMed1989

The secretion of high molecular weight cathepsin B from cultured human liver cancers.

The biochemical characteristics of cathepsin B secreted from cultured human liver cancer cells were examined. The enzyme activity of culture medium against a synthetic substrate, N-carbobenzoxy-L-arginyl-L-arginine-4-methyl-coumaryl-7-amide, was dependent on the addition of cysteine, and the optimal pH was found to be 6.0. No activity was observed when the enzyme source was fresh medium not used for culture. These results suggest that the enzyme released from liver cancer cells is the thiol-protease cathepsin B. The molecular weight of the enzyme with 90% of the total activity was 40,000. Two cathepsin B molecules were found in liver tissue from patients with hepatocellular carcinoma (HCC); one was equivalent in size to the secreted enzyme, and a smaller one was the same as normal liver cathepsin B (27,000), which was also obtained from HCC-bearing cirrhotic liver. These results demonstrate that two molecules of cathepsin B are synthesized in liver cancer, and that the larger one is released into the surrounding tissue.

Cathepsin B↗
PubMed1989

Nephrotoxicity of pyrroloquinoline quinone in rats.

When pyrroloquinoline quinone (PQQ) was intraperitoneally injected into rats daily for 4 days at a dose of 11.5 mg/kg body weight/injection, functional and morphologic changes of the kidneys were clearly observed. The most prominent finding was necrotic and degenerative changes of the proximal tubular epithelium as well as hematuria and an elevation of serum creatinine concentration.

Animals↗