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Biomedical subjects

K Shimada

Publications and source records attributed to K Shimada.

At least 883 records · Page 49Linked to original sources
PubMed1994

[A case of capillary hemangioma of the testis in a child].

Testicular tumors derived from connective tissue, blood vessels and musculature are uncommon and intratesticular tumors of vascular origin are extremely rare. A rare case of capillary hemangioma of the testis in a child is reported. An 11-year-old boy was admitted with the chief complaint of painless mass in the right scrotum. He was diagnosed with a right testicular tumor by physical examination and ultrasonography, preoperatively. Right high orchiectomy was done on December 10, 1990. The testis measured 2.5 x 2.3 x 1.5 cm. Pathologically, the tumor was diagnosed as a capillary hemangioma of the testis.

Child↗
PubMed1994

[An experience of suprahyoid release for resection and reconstruction of the lower part of trachea].

An experience of suprahyoid release for resection and reconstruction of the lower part of trachea was reported. 51-year-old woman, complaining of continuous stridor, was diagnosed as tracheal tumor at another hospital and was transferred to our hospital for consecutive examination and surgical treatment. The size of the tumor was about 3 cm in longitudinal diameter and the distance between tracheal carina and lower edge of the tumor was estimated about 2 cm by tomography. At operation, following suprahyoid release in supine position, 6 tracheal rings were resected and reconstructed by end-to-end anastomosis through right posterolateral incision. Patients neck was forced to bend for three weeks and intravenous byperalimentation without oral intake was employed for two weeks to avoid misswallowing and dysphagia postoperatively. Oral intake was started at two weeks after operation and parenteral nutrition was no more necessary at 3 weeks after surgery. Misswallowing and dysphagia were not encountered at all. The tumor was diagnosed as adenoid cystic carcinoma pathologically and residual tumor was demonstrated in submucosal space at the oral margin of the resected specimen as well. She discharged from the hospital uneventfully after postoperative radiotherapy. The recurrence of the tumor has not been observed for 3 years postoperatively. It was confirmed that suprahyoid release is an useful technique and should be ready to introduce in the extensive resection of the trachea because of its little influence on laryngeal function.

Anastomosis, Surgical↗
PubMed1993

Differential controls of small and large motor unit activity in the masseter muscle with incisal stimulation in humans.

The activity of masseter motor units with different spike amplitudes was recorded and reflex responses by force stimulation of an incisor were analyzed in humans. The effects of reflex responses varied depending on the level of prestimulus firing frequency (background activity, BGA). When small amplitude motor units and large amplitude motor units were tested at the same level of BGA, the former tended to exhibit excitatory reflexes and the latter inhibitory ones.

Action Potentials↗
PubMed1993

Energy transfer processes in Rhodopseudomonas palustris grown under low-light conditions. Heterogeneous composition of LH 2 complexes and parallel energy flow pathways.

Excitation energy flow in the purple photosynthetic bacterium Rhodopseudomonas palustris grown under a low-light intensity was studied by time-resolved fluorescence spectroscopy in the ps time range. This bacterium synthesized the B824 component under this light condition. Time-resolved spectra at 20 degrees C indicated the sequential energy flow in the order of B803, B856, B882 and B900, long wavelength antenna. An emission from B803 was not observed. A remarkable feature was the emission from B824 throughout the measuring time. After the excitation pulse of 100 ps, the spectra did not change any further, indicating the establishment of an equilibrium among components. Based on the energy distribution after equilibrium, parallel energy transfer pathways to LH 1 were suggested; one including B824 integrated in the B803-824-856 complex, and the other, from the B803-856 complex to B882. The latter was the dominant energy flow pathway in this bacterium.

Bacterial Proteins↗
PubMed1993

Distinctive expression of lprcg in the heterozygous state on different genetic backgrounds.

Much knowledge of the etiopathogenesis of human autoimmune diseases has been obtained from the mutant mouse models carrying lpr and gld. These autoimmune genes have been regarded as autosomal recessive. The novel lymphoproliferative and autoimmune mutation lprcg is unique in its interaction with gld despite their different chromosomal locations: chromosomes 19 and 1, respectively. Both lprcg and lpr mutations are shown to be the defects in the Fas antigen gene that controls apoptosis. Evidence has been provided for the partial expression of lpr in the heterozygous state and the significant influences of background genes on lpr-induced autoimmune disorders. To investigate the expression of the heterozygous lprcg and the effects of background genes on it, anatomical, serological, and pathological manifestations were compared among lprcg/lprcg,lprcg/+, and +/+ mice on both MRL/MpJ (MRL) and CBA/KlJms (CBA) backgrounds. On the MRL background, lymph nodes (LN) and spleens of lprcg/+ were significantly larger in weight than those of +/+, but far lower than those of lprcg/lprcg mice. In accord with this, these lprcg/+ mice had intermediate levels of anti-single-stranded DNA antibodies, circulating immune complexes, and serum Igs between those of lprcg/lprcg and +/+ mice and were similar to lprcg/lprcg mice in severity of glomerulonephritis. However, accumulation of anomalous CD4-8- T cells characteristic of the lpr disease was not proved in the enlarged lprcg/+ LN. On the CBA background, the LN and spleen weight increases in lprcg/+ were statistically significant compared to +/+ mice but were minimal, being regarded as clinically insignificant. In support of this, lprcg/+ mice were not different from +/+ mice in any of the serological and pathological parameters examined. The results clearly demonstrate that the lprcg gene can function to induce autoimmune disorders in the heterozygous state on the MRL but not on the CBA background.

Animals↗
PubMed1993

Disruption of the transthyretin gene results in mice with depressed levels of plasma retinol and thyroid hormone.

Transthyretin (TTR) is thought to play a major role in vitamin A metabolism and thyroid hormone transport in mammals. To investigate the physiological role of the TTR protein in development of the embryo and in the adult, we used gene targeting techniques to generate a null mutation at the mouse ttr locus. The resultant mutant animals are phenotypically normal, viable, and fertile. However, levels of serum retinol, retinol-binding protein, and thyroid hormone are significantly depressed in the mutant animals. These observations demonstrate that the TTR protein maintains normal levels of these metabolites in the circulating plasma.

Animals↗
PubMed1993

Spontaneous remission in Cushing's disease.

Two patients with Cushing's disease underwent spontaneous clinical and biochemical remission following a period of secondary adrenal insufficiency. One of the patients was untreated, while the other had been treated with partial bilateral adrenalectomy before. Both patients underwent remission shortly after the administration of dexamethasone for diagnostic purposes and remained symptom free for 2 and 3 years, respectively, which was followed by relapse of the disease. We conclude that although resolution of Cushing's disease may occur spontaneously, probably by hemorrhagic infarction of corticotroph microadenomas, careful follow-up studies are required since the relapse of the disease occurs later in some patients.

Adrenalectomy↗
PubMed1993

Detection of antibody IgG to HIV-1 in urine by sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant proteins as antigens for diagnosis of HIV-1 infection.

For diagnosis of HIV-1 infection, attempts were made to detect anti-HIV-1 IgG in urine by sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant reverse transcriptase (RT) and p17 as antigens. Anti-HIV-1 IgG in urine was reacted simultaneously with 2,4-dinitrophenyl-bovine serum albumin-recombinant protein conjugate and recombinant protein-enzyme conjugate. The enzymes used as labels were horseradish peroxidase for RT and Escherichia coli beta-D-galactosidase for p17. The complex formed, consisting of the three components, was trapped onto polystyrene balls coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG, eluted with epsilon N-2,4-dinitrophenyl-L-lysine and transferred to polystyrene balls coated with affinity-purified (anti-human IgG gamma-chain) IgG. Finally, bound enzyme activity was assayed by fluorometry. Urine samples were collected from 100 seronegative subjects and 70 seropositive subjects. The sensitivity and specificity were both 100% with unconcentrated urine samples. The positivity was confirmed by preincubation of urine samples with excess of the antigens. The positivity and negativity with one of the two antigens could be confirmed with the other antigen. The positivity with low signals could be confirmed by concentration of urine samples. Detection of anti-HIV-1 IgG in urine by the immune complex transfer enzyme immunoassay using different antigens would make diagnosis of HIV-1 infection possible.

Adolescent↗
PubMed1993

Direct monitoring as well as sensitive diagnosis of Pneumocystis carinii pneumonia by the polymerase chain reaction on sputum samples.

In order to evaluate the usefulness of the polymerase chain reaction (PCR) for diagnosis and monitoring of Pneumocystis carinii pneumonia (PCP) in specimens obtained from non-invasive techniques, expectorated or induced sputa were collected from 30 patients who were tentatively diagnosed as having PCP and administered intravenous trimethoprim-sulfamethoxazole. Using appropriate criteria, 13 of these cases were diagnosed as having PCP, 12 cases were diagnosed of other pulmonary diseases, and five cases were omitted from the study according to the exclusion criteria. PCR was performed using primers based on the P. carinii 5S rRNA sequence. Pneumocystis carinii was detected in nine of the 13 defined cases (sensitivity of 69%) and in none of 12 non-PCP cases (specificity of 100%). In contrast, P. carinii was detected in only one case by microscopic examination using Diff-Quik stain. Therefore, the sensitivity of PCR was significantly higher than that observed with the stain (P < 0.05, chi 2 = 6.125). Sputum samples were also obtained from eight cases during the treatment. The eradication of P. carinii from the sputum as judged by PCR varied from three to 38 days (median 6.5 days) after the start of the treatment. Pneumocystis carinii shedding in sputum correlated with the time between initial clinical symptoms and initiation of the treatment (P < 0.05, r = 0.810), but not with the tension of PaO2 at the time of diagnosis. This preliminary study demonstrates that PCR allows early diagnosis of PCR and that close monitoring with non-invasive specimens can be performed by PCR.

Adrenal Cortex Hormones↗
PubMed1993

Four novel gene mutations in five Japanese male patients with neonatal or late onset OTC deficiency: application of PCR-single-strand conformation polymorphisms for all exons and adjacent introns [corrected].

Ornithine transcarbamylase deficiency (OTC), the most common inborn error of the urea cycle, shows an X-linked inheritance with frequent new mutations. Southern blots reveal only a small percent of the mutation, but amplification of cDNA or genomic DNA using the polymerase chain reaction (PCR) followed by DNA sequencing, has contributed greatly to overcoming this difficulty. Problems remaining are the limited availability of fresh liver samples for preparation of intact mRNA in the former case, and there are primer sequences for PCR for only some exons in the latter case. Here, we report the structures of intron sequences which are long enough to analyze all exons and adjacent introns of the OTC gene using PCR and PCR single-strand conformation polymorphisms (PCR-SSCP). We carried out a DNA analysis of findings in five Japanese male patients with neonatal or late onset form. Five patients had mutations in the protein coding region. C to G (S192R), A to T (D196V), A to G (T264A), T to C (M268T), and C to T (R277W) substitutions. The first four of these were novel missense mutations and the presence of the mutation was confirmed in the corresponding families.

Asian People↗