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Biomedical subjects

A Yamazaki

Publications and source records attributed to A Yamazaki.

At least 145 records · Page 8Linked to original sources
PubMed1987

[Studies on the usefulness of a long-term, high-dose treatment of methylcobalamin in patients with oligozoospermia].

Methylcobalamin (CH3-B12) was administrated in a dose of 6 mg per day (group A, 16 cases) or 12 mg per day (group B, 23 cases) for 16 weeks to patients with oligozoospermia. There was no difference between group A and group B regarding vitamin B12 concentrations in the serum or seminal fluid. CH3-B12 appeared to be transported to seminal fluid very efficiently. However, results from group A and group B did not differ with respect to this parameter. The efficacy rate for group A was 37.5% and that for group B was 39.1%. From these results, it was concluded that a long-term, high dose treatment of CH3-B12 was useful for the treatment of patients with oligozoospermia. Since the efficacy rates were not different between the two groups, 6 mg per day would be the recommended dose. Clinical adverse reactions were observed in one patient in each group. Drug-related laboratory adverse reactions were observed in only one patient in group B.

Adult↗
PubMed1987

[Clinical statistics at the Department of Urology, Kitano Hospital (1968-1986)].

A clinical statistic survey was carried out on the patients, diseases and operations experienced at our department between 1968 and 1986. In 1968, the urological department became independent from the dermato-urological department, and in 1981 the urological ward was established. The 19 years are divided in three periods; first period: 1968-1974 (7 years), second period: 1975-1981 (7 years), and third period: 1982-1986 (5 years). The total number of new outpatients during the 19 years was 50,443. They have gradually but steadily increased and have reached recently about 4,000 per year. The total number of inpatients was 3,422 (male: 2,561, female: 861). The proportion of the elderly patients, especially male, has remarkably increased and that of patients more than 60 years old was 44.9% of all inpatients in the third period. Among the major diseases of the inpatients, tumors has got most remarkable increase of its number and proportion. And among tumors, increases of benign prostatic hyperplasia, bladder cancer, prostatic cancer were prominent and at the third period the proportion of those three has reached 81.3% of all tumors. Percutaneous nephrolithotripsy (PNL) and transurethral ureterolithotripsy (TUUL) were introduced in 1985. Recently endoscopical operations such as transurethral resection (TUR), PNL, TUUL and so forth have become a large part of the urological operations.

Adolescent↗
PubMed1985

Characterization by two-dimensional peptide mapping of the gamma subunits of Ns and Ni, the regulatory proteins of adenylyl cyclase, and of transducin, the guanine nucleotide-binding protein of rod outer segments of the eye.

Ns and Ni, the regulatory proteins affecting adenylyl cyclase, and transducin, the guanine nucleotide-binding protein from rod outer segments of the eye, are structurally and functionally related proteins. Of these, the alpha subunits are between 39 and 42 kDa in mass, beta subunits are all of 35 kDa in mass, and gamma subunits are much smaller, of approximately 5-8 kDa in mass. We compared, by two-dimensional peptide mapping of iodinated peptides, the beta and gamma subunits of human erythrocyte Ns, human erythrocyte Ni, the beta gamma complex derived from purification of bovine brain N proteins, and frog and bovine eye transducins. We found that gamma subunits in human erythrocyte Ns and Ni and in bovine brain beta gamma complex are indistinguishable by this approach. In contrast, gamma subunits associated with frog and bovine transducin differed markedly between each other and from N protein-associated gamma. beta subunits, on the other hand, yielded essentially indistinguishable peptide maps regardless of whether derived from N proteins or from transducin and regardless also of species of origin: human versus bovine versus frog. These results suggest that the gamma subunit may impart functional heterogeneity of this family of proteins which is evident in the N proteins on the one hand and the transducin proteins on the other.

Animals↗
PubMed1985

Evidence for the dissociation of morphine analgesia, tolerance and dependence.

A single large dose of morphine produced profound analgesia accompanied by the development of tolerance and physical dependence. The tolerance developed acutely within 24 h and was further intensified, reaching a peak on the 5th day, then gradually disappeared. Partial or complete masking of morphine analgesia by naloxone inhibited the development of the acute, but could not prevent the development of the delayed, tolerance. These results suggest there are two kinds of tolerance and that the analgesic effect is separate from tolerance. Similarly, treatment with morphine produced physical dependence which was precipitated by naloxone. Unlike tolerance, dependence did not develop when morphine analgesia was completely masked by naloxone. The findings provide for the dissociation or morphine analgesia, tolerance and dependence.

Analgesics↗
PubMed1985

Single dose tolerance to the analgesic effect of clonidine and cross-tolerance between morphine and clonidine.

A single dose of clonidine developed tolerance to its analgesic effect. The tolerance reached its peak acutely on the 2nd day and lasted more than 5 days. Neither the analgesic effect nor the development of tolerance was modified by the pretreatment with naloxone. On the 2nd day, clonidine tolerant animals were also tolerant to morphine, but morphine tolerant animals, after a single dose of morphine on the 1st day, were not tolerant to clonidine. On the 5th day, however, clonidine tolerant animals were tolerant to morphine, and vice versa. Thus, the interaction between morphine and clonidine was "one-way" on the 2nd day, and cross-tolerance was only demonstrated on the 5th day. With a treatment with clonidine plus naloxone on the 1st day, the development of cross-tolerance to morphine was completely suppressed on the 2nd day but not on the 5th day. These results confirmed our previous finding that acute and delayed tolerance are different in nature, and the development of tolerance to morphine and clonidine are partially underlaid with a common mechanism which is not mediated by opioid receptors.

Analgesics↗
PubMed1985

[Interference in the Stroop color-naming task].

To clarify the four processing stages in the Stroop task (input, decision, response selection, and output), and to examine on which stage or stages the interference occurs, seven undergraduates were used as subjects in a color-naming task with color names, words strongly associated with color, words weakly associated with color, a neutral word, and "X X X" as control stimulus. Color-patch pieces were also used to measure the operant level of reaction time. Main results were as follows: 1. On the congruent trials, the response time was shorter for color names than for the neutral word, control word, and words with weak association. 2. On the incongruent trials, the response time was longer for color names than for the neutral word, control word, and words with weak and strong association. Moreover, the interaction between pre-exposure duration and word conditions was significant; the difference of response time due to word conditions as significant when the pre-exposure duration was short, while it was not significant when the duration was long. 3. The neutral word and the control word gave similar response time, which was longer than that for color-patch pieces. From these results it is concluded that the interference in the Stroop task is most likely to occur on the decision and the output stages.

Adult↗
PubMed1985

Determination of the complete nucleotide sequence of the Brevibacterium lactofermentum plasmid pAM330 and the analysis of its genetic information.

The complete nucleotide sequence of the plasmid pAM330 derived from Brevibacterium lactofermentum ATCC 13869 was determined using the dideoxy chain termination method. Analysis of the sequence allowed us to observe seven open reading frames, one of which showed the presence of the promoter and the Shine-Dalgarno (SD) sequences upstream from the initiation codon.

Base Sequence↗
PubMed1985

[Threshold of penicillin induced epileptiform afterdischarge in brain slices of guinea pig].

Investigation of the regional threshold for epilepsy in many structures in the brain would contribute to the study of epileptogenesis. So we studied the threshold for epileptiform afterdischarge in the neocortex, hippocampus and cerebellar cortex using Na-Penicillin -G (Pc) of which epileptogenesis has been intensively investigated. In order to eliminate the influence from the outside of these structures, the brain slice method was utilized. Procedures for preparation of the tissue and incubation were about the same as those described by Yamamoto. In summary, after sacrifice, brain of the guinea pig was taken out and the hippocampus, neocortex and cerebellum were cut with a razor blade under a microscope. The thickness of the section was about 0.3 mm. Slices were incubated at 37 degrees C for about 30 min in the standard medium perfused with 95% O2 and 0% CO2. The chamber was continuously perfused with the standard medium which composed of NaCl, 124 mM, KCl, 5: KH2PO4, 1.24; MgSO4, 1.3; CaCl2, 2.4; NaHCO3, 26; and glucose, 10. Evoked potentials were elicited by electrical stimulation in the standard medium. Mossy fibers were stimulated and responses were recorded from the CA3 area in the hippocampus by glass pipette microelectrode. Subcortical white matter was stimulated and responses were recorded from the Purkinje cell layer in the cerebellum. Pc was added in the standard medium until epileptiform afterdischarges were superimposed on the evoked potentials. The results of this experiment demonstrated that each structure in the brain has a regional own threshold for Pc induced epileptiform afterdischarge.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

[A case of papillary adenocarcinoma of the prostate].

A relatively rare case of papillary adenocarcinoma of prostate is reported. The patient was a 49-year-old male. He presented with the chief complaints of micturition frequency, a feeling of residual urine and a burning sensation in urethra. There was no palpable abnormality in the prostate. Endoscopic examination revealed papillary tumors in the prostatic urethra and the anterior urethra, but no evidence of abnormality in the utricle. Both hematological examination and blood chemistry revealed no abnormalities; ACP, PACP and PAP were normal. The tumors were resected by TUR on March 8, 1982. Histopathological findings indicated papillary proliferation of single layer of columnar epithelium, with clear cytoplasm and nuclei with atypism distributed in the base. The tumors in the anterior urethra gave the same findings, and the diagnosis made was papillary adenocarcinoma which seemed to have originated from the prostatic duct. After operation, hormone therapy and chemotherapy with peplomycin were conducted. Eleven months after the operation, the remaining prostatic tissues including surgical capsule were resected as completely as possible. Histopathological findings revealed only atrophic prostatic tissues without any remaining tumor. The hormone therapy was discontinued. Presently, 19 months has elapsed since the first TUR. His micturition condition is good without evidence of recurrence or metastasis.

Adenocarcinoma, Papillary↗
PubMed1984

[A case of renal adenoma associated with staghorn calculus].

A case of renal adenoma associated with staghorn calculus is reported. The patient was a 52-year-old man. In 1973, he underwent an ileal conduit because of tuberculous contracted bladder and impediment in renal function. At that time, small calculi were already present in the right kidney. Later, in the left kidney, calculi developed into staghorn calculus. An ureteral calculus was also present in the right side and contracted kidney was observed. In 1983, he suffered from continuous left abdominal pain and macroscopic hematuria. Left nephrolithotomy was performed on August 23, 1983. During surgery, a yellow subcapsular flat mass the size of the tip of an index finger was found in the upper pole of the left kidney and was easily excised. An 11 cm incision was made in the renal parenchyma and the calculi were completely removed. At the center of the incised region, biopsy was performed. The wound was closed by the one-layer interrupted parenchymal suture method designed by Taguchi. Pedicle clamp time was 37 minutes and postoperative macroscopic hematuria was seen for only two days. The postoperative course was uneventful. The resected tumor was 18 X 16 X 10 mm in size. Histological examination revealed presence of fibrous capsules and papillary or tubular proliferation of cells which were suspected to have originated in the renal tubule. Also, there were scattered nests of foam cells. On the basis of these histological findings, the mass was diagnosed as renal adenoma. In addition, examination of the biopsied parenchyma also revealed small multiple adenomas, which were supposed to be remaining in the left kidney.

Adenoma↗