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Biomedical subjects

S Okada

Publications and source records attributed to S Okada.

At least 865 records · Page 48Linked to original sources
PubMed1992

[Function, molecular structure and gene expression of stem cell factor (SCF)].

Mice of genotype W/Wv and Sl/Sld have been considered as a model of instinct hemopoietic disorders. W/Wv mice have a defect in hemopoietic stem cells and Sl/Sld mice have a defect in the microenvironment. The W locus in murine chromosome 5 encodes the c-kit proto-oncogene and the Sl locus in chromosome 10 encodes the ligand for c-kit, which has been named stem cell factor (SCF), mast cell growth factor (MGF), kit ligand (KL) and steel factor (SL). The cDNA sequence of SCF suggest that it is synthesized as an integral transmembrane protein and that it has common tertiary structure with M-CSF. SCF enhances the proliferation of hemopoietic stem cells and progenitor cells as well as mast cell in combination with other growth factors. Furthermore, it plays an important role in the proliferation and migration of embryonic stem cell, primordial germ cell and melanocyte.

Amino Acid Sequence↗
PubMed1992

An alpha-fetoprotein-producing carcinoma of the rectum.

A rare alpha-fetoprotein (AFP)-producing carcinoma that originated in the rectum of a 54-year-old man is reported. High levels of AFP are found in the serum (5,126 ng/ml) and homogenate of the tumor tissue (2,600 ng/g). Two morphologic patterns were noted in the tumor. One was that of well differentiated tubular adenocarcinoma and the other was more polymorphous, in which the tumor cells grow in a solid-sheet with occasional glandular and papillary structures. Hyaline bodies and Schiller-Duval body-like structures were also found in the polymorphous area. There was a gradual transition between the well differentiated and the polymorphous area. AFP was positive in the polymorphous area and negative in the well differentiated area on immunohistochemical examination. These morphologic and immunohistochemical characteristics may suggest a differentiation toward embryonal carcinoma of the polymorphous component. Moreover, the polymorphous component showed marked vascular invasion and metastasis of liver as well as regional lymph nodes. AFP-producing carcinoma cells may be more aggressive than ordinary adenocarcinoma.

Adenocarcinoma↗
PubMed1992

[High-field-strength magnetic resonance imaging and SPECT of multiple system atrophy].

Two cases of multiple system atrophy (MSA) showing similar abnormalities by magnetic resonance (MR) imaging and SPECT are reported. The clinical diagnoses of the two cases were striatonigral degeneration (SND) and sporadic olivopontocerebellar atrophy (OPCA). In addition, one case of sporadic OPCA without parkinsonism was used for comparison. The MR images were obtained using a 1.5-T MR system and included spin-echo transverse sections with T1-weighted images (TR = 450 ms and TE = 15 ms) and T2-weighted images (TR = 2500 ms and TE = 90 ms). The T1-weighted images demonstrated atrophy of cerebellum and pons, with increased signal intensity in the bilateral putamen. The T2-weighted images demonstrated decreased signal intensity in the putamen, as reported recently. SPECT demonstrated reduced uptake in the celleberum, basal ganglia and frontal lobe cortex. The putaminal changes evident on T1-weighted images may have resulted from deposition of pigments such as neuromelanin and lipofuscin, related to parkinsonism. Both T1- and T2-weighted MRI seem to be useful clinical diagnosis of MSA.

Brain↗
PubMed1992

Radiotherapy for bone metastases of hepatocellular carcinoma.

Radiotherapeutic effects of 42 bone metastases in 26 hepatocellular carcinoma patients were retrospectively analyzed. Pain relief was observed in 79% of 37 bone metastases treated (29/37). Antitumor effects and improvement of paralysis were also observed in 88% (8/9) and 17% (1/6), respectively. The toxicities experienced were tolerable. Radiotherapy was an effective means of palliation in the treatment of hepatocellular carcinoma bone metastases.

Adult↗
PubMed1992

[A case of carcinomatous autonomic and sensory neuropathy].

A 61-year-old male with carcinomatous autonomic and sensory neuropathy was presented. The disease started with numbness in his lower extremities and loss of sensation gradually developed over the upper extremities within two months. Finally he became unable to walk because of orthostatic hypotension and dystaxia due to loss of deep sensation. Physical examination on admission revealed mydriasis with negative light reflex, orthostatic hypotension, sensory loss of below C-4, areflexia, positive Babinski's sign and sexual impotence. Laboratory examinations revealed serum antineural antibody, elevation of protein and oligoclonal IgG band in the CSF. Sural nerve biopsy specimen showed severe loss of myelinated fibers, especially in the large-sized fibers. The pharmacological functional tests of the autonomic nerves disclosed disturbance of parasympathetic nervous system as well as the postsynaptic fibers of the sympathetic nerves. An instillation test of 2.5% mecholyl solution demonstrated contraction of both pupils. Chest X-ray showed abnormal shadow at the right hilus and transbronchial biopsy revealed small cell carcinoma (oat cell type). Plasma exchange improved orthostatic hypotension and decreased the titer of the antineural antibody. In this case, the autonomic ganglion including the ciliary ganglia and the dorsal root ganglia cells were predominantly involved and such cases have been described as a variant of paraneoplastic syndrome in the literature.

Autonomic Nervous System Diseases↗
PubMed1992

Immunoglobulin-complexed aspartate aminotransferase with a possible association with ulcerative colitis and its activity.

We demonstrate immunoglobulin-complexed aspartate aminotransferase (macro-AST) in a 14-year-old boy with rectitis-type ulcerative colitis by using both gel filtration and electrophoresis methods. The immunoglobulin complexed with AST in this case was identified as an IgG kappa both by electrosyneresis and immunoprecipitation reactions. The present case was noted to have a concomitant elevation of macro-AST associated with deterioration of ulcerative colitis. However, macro-AST has continued to exist when the activity of ulcerative colitis subsided, and the serum level of AST became normal. Thus, macro-AST might be related to an immunological component of ulcerative colitis as well as to the activity of the disease.

Adolescent↗
PubMed1992

Synergistic effect of IL-3 and IL-6 on highly enriched murine hemopoietic progenitors.

It has been reported that interleukin 6 (IL-6) acts on hemopoietic stem cells in synergism with interleukin 3 (IL-3), but it has not yet been clarified whether IL-6 acts directly on the stem cells or not. To investigate the mechanism of the synergism between IL-3 and IL-6, we sorted hemopoietic stem cells from untreated murine bone marrow cells using a two-laser fluorescence-activated cell sorter (FACS). Cells negative for the lymphohemopoietic lineage (lineage-negative, Lin-), with a high affinity to wheat germ agglutinin (WGA+), and showing a low expression of Thy-1 antigen (Thy-1low) were sorted and analyzed by in vitro and in vivo colony formation. This fraction was 0.4% of the total mononuclear bone marrow cells. Approximately 25% of these Lin-WGA+Thy-1low cells showed in vitro colony formation, whereas approximately 1% of them formed day-8 and day-12 spleen colonies. Thus, it appears that the Lin-WGA+Thy-1low cells were a highly enriched stem cell population. By FACS clone sorting, single cells were isolated from the enriched stem cell fraction and cultured in semisolid or liquid culture systems. Addition of IL-6 to methylcellulose medium containing IL-3 did not significantly increase the number of colonies. It is thus suggested that the target cells of IL-3 and IL-6 are the same as those of IL-3. The secondary colony-forming ability of primary colonies that developed in the presence of IL-6 and IL-3 was higher than that of colonies formed in the presence of IL-3 alone. In correspondence with this finding, the numbers of myeloid colonies and spleen colony-forming units (CFU-S) were increased by the incubation of these sorted cells for 7 days with IL-6 and IL-3 when compared with the effect of IL-3 alone. Therefore, it is concluded that IL-6 acts directly on hemopoietic stem cells to enhance their proliferation.

Animals↗
PubMed1992

[Pyridoxine hydrochloride reference standard (Control 911) of the National Institute of Hygienic Sciences].

The raw material of pyridoxine hydrochloride was examined for preparation of the "Pyridoxine Hydrochloride Reference Standard". Analytical data obtained were as follows: loss on drying, 0.00%; pH, 2.87; melting point, 204.6 degrees C (decomposition); infrared spectrum, same as Pyridoxine Hydrochloride Reference Standard (Control 879); thin-layer chromatography, nonimpurities were detected; assay, 100.0% by non-aqueous titration and 100.0% by UV spectrophotometry. Based on the above results, the raw material was authorized as the Japanese Pharmacopoeia Standard (Control 911).

Chromatography, Thin Layer↗
PubMed1992

[Tocopherol reference standard (Control 911) of the National Institute of Hygienic Sciences].

The raw material for tocopherol was tested for preparation of the "Tocopherol Reference Standard (Control 911)". Analytical data obtained were as follows: infrared spectrum, same as Tocopherol Reference Standard (Control 881); absorptivity, E1%1cm (292nm) = 75.5; thin-layer chromatography, no impurities were detected up to 50.0 micrograms; high performance liquid chromatography (HPLC), four impurities were detected; assay, 100.7% by HPLC. Based on the above results, the raw material was authorized as the Japanese Pharmacopoeia Standard (Control 911).

Chromatography, High Pressure Liquid↗
PubMed1992

[Prednisolone reference standard (Control 911) of the National Institute of Hygienic Sciences].

Prednisolone was tested for preparation of the "Prednisolone Reference Standard (Control 911)". The quality of raw material was examined and compared with the previous Reference Standard (Control 872). Analytical data obtained were as follows: loss on drying, 0.10%; melting point, 233.2 degrees C (decomposition); optical rotation, [alpha]20D+98.77 degrees; UV spectrum, lambda max = 243nm; absorptivity, E1%1cm (243nm) = 413.5; IR spectrum, 1711, 1612, 1110, 888cm-1; one impurity was detected by thin-layer chromatography and high-performance liquid chromatography (HPLC), respectively; assay, 100.1% by HPLC. Based on the above results, the raw material was authorized as the Japanese Pharmacopoeia Standard (Control 911).

Chromatography, Thin Layer↗
PubMed1992

[d-Camphor reference standard (Control 911) and dl-Camphor Reference Standard (Control 911) of the National Institute of Hygienic Sciences].

The raw materials of d-camphor and dl-camphor were examined for preparation of the "d-Camphor Reference Standard" and "dl-Camphor Reference Standard". Analytical data obtained were as follows: ultraviolet spectrum, lambda max = 290nm; infrared spectrum, 2958, 1742, 1045cm-1; optical rotation, [alpha]D20 = +42.7 degrees (d-camphor), [alpha]D20 = -0.3 degrees (dl-camphor); melting point, 180 degrees C (d-camphor), 179 degrees C (dl-camphor); gas-chromatography (GC), one impurity was detected in d-camphor and three impurities in dl-camphor; assay, 99.5% (d-camphor), 99.5% (dl-camphor) by GC. Based on the above results, these raw materials were authorized as the Japanese Pharmacopoeia Standard (Control 911).

Camphor↗
PubMed1992

[Tocopherol acetate reference standard (Control 911) of the National Institute of Hygienic Sciences].

The raw material for tocopherol acetate was tested for preparation of the "Tocopherol Acetate Reference Standard (Control 911)". Analytical data obtained were as follows: infrared spectrum, same as Tocopherol Acetate Reference Standard (Control 881); absorptivity, E1cm1% (284nm) = 43.5; thin-layer chromatography, no impurities were detected up to 50.0 micrograms; high performance liquid chromatography (HPLC), two impurities were detected; assay, 100.3% by HPLC. Based on the above results, the raw material was authorized as the Japanese Pharmacopoeia Standard (Control 911).

Chromatography, High Pressure Liquid↗
PubMed1992

[Quality tests for ibuprofen preparations].

Ibuprofen preparations were tested with a view to checking their quality by physical methods such as determination, disintegration and dissolution tests. These studies were carried out on 48 kinds of commercial ibuprofen preparations. The drug content of each preparation was measured by spectrophotometry (264nm), and the values were in the range of 90-110%. In the disintegration tests of 36 tablets, a few tablets of two preparations failed to disintegrate completely after 60 minutes. However the number of such tablets was within the limit specified in JP. The dissolution test described in the USP monograph was also applied to the 36 tablets, and it was found that 9 tablets failed the test provision that over 70% of the tablets must be dissolved within 30 minutes.

Ibuprofen↗
PubMed1992

[A case of urinary bladder hernia].

A 77-year-old male visited our hospital complaining of swelling in the right scrotal and inguinal region, urinary urgency and difficulty of urination. Physical examination revealed an elastic soft mass in the right inguinal region toward the right scrotum. Rectal examination proved that the prostate was moderately enlarged. Cystogram and urethrography showed hernia of the bladder into the right scrotum and benign prostatic hyperplasia. Urodynamic studies demonstrated organic obstruction in the lower urinary tract. Transurethral resection of the prostate was done for benign prostatic hyperplasia. Later, surgical treatment for the bladder hernia was performed by replacing the bladder into the pelvic cavity and closing the hernial ring without resection of the bladder wall. The bladder hernia proved to be a para-peritoneal type. The postoperative course was uneventful. The previous reports of urinary bladder hernia are reviewed and the incidence, etiology, diagnosis the treatment are discussed.

Aged↗
PubMed1992

Alpha-fetoprotein producing carcinoma of the gallbladder associated with anomalous arrangement of the pancreaticobiliary ductal system--early detection through an attack of acute pancreatitis.

A 56-year-old female was admitted to our hospital with a diagnosis of acute pancreatitis. Ultrasonography revealed a hypoechoic tumor in the gallbladder. The serum alpha-fetoprotein (AFP) level was 971 ng/ml. After healing of the acute pancreatitis, the anomalous arrangement of the pancreaticobiliary ductal system (APDS) was demonstrated by ERCP with mild dilatation of the common bile duct. Within one month after admininon, AFP level reached 4390 ng/ml. On operation, a pedunculated tumor, 6.5 x 3 cm in size, was found in the gallbladder. Histological examination revealed a moderately differentiated adenocarcinoma and positive immunohistochemical staining of cancer cells for AFP. After absolutely curative (stage II) resection, normal serum AFP levels were recognized. This is the first report of an AFP-producing cancer of the gallbladder associated with APDS and it was detected as a result of an attack of acute pancreatitis.

Acute Disease↗
PubMed1992

[A case of hydropneumothorax].

A 19-year-old girl was admitted because of fever, cough and suddenly occurred chest pain. One month earlier she had experienced a fever and cough, then she had felt sudden chest pain 2 weeks prior to the admission. A chest X-ray showed left pneumothorax and massive pleural effusion. A diagnosis of hydropneumothorax was made. In spite of the chest tube drainage, reexpansion of the lung was unsatisfactory. Thoracotomy and decortication of the lung resulted in good reexpansion. Histological finding revealed pleuritis due to bacterial peribronchial infection, which resulted in hydropneumothorax, namely an abscess ruptured to the pleural cavity.

Adult↗