Search PubMed⌕ Search

Biomedical subjects

A Katayama

Publications and source records attributed to A Katayama.

At least 73 records · Page 4Linked to original sources

Lung metastasis from parathyroid carcinoma causing recurrent renal hyperparathyroidism in a hemodialysis patient: report of a case.

We report herein the case of a 46-year-old woman on hemodialysis (HD) who developed recurrent renal hyperparathyroidism induced by lung metastasis from parathyroid carcinoma. The patient had been commenced on HD for chronic renal failure about 20 years earlier and had undergone a parathyroidectomy for advanced renal hyperparathyroidism 8 years later. After the initial operation, further explorations of the neck were performed due to recurrence, despite which the hyperparathyroidism persisted and she was finally referred to our department. The appearance of multiple coinlike lesions on a chest X-ray and computed tomography led to the diagnosis of recurrent hyperparathyroidism induced by lung metastasis from parathyroid carcinoma. A pulmonary wedge resection was performed and the metastatic parathyroid nodules were removed. Of the several hypotheses about the etiology of parathyroid carcinoma in HD patients, it is most likely that the parathyroid hyperplasia induced by chronic renal failure develops into carcinoma. Even in renal hyperparathyroidism, we should bear in mind the possibility that metastatic parathyroid carcinoma is a possible source of excess parathyroid hormone secretion at recurrence.

Carcinoma↗

Endothelin-1 and in vitro evidence of renal artery vasoconstriction after liver transplantation.

Twelve pigs underwent orthotopic liver transplantation. The mean endothelin-1 (ET-1) levels in the serum samples of the recipient animals 1 h after reperfusion of the graft (6.2 +/- 1.5 pg/ml) was significantly higher (P < 0.05) than in pretransplantation samples (3.2 +/- 0.6 pg/ml). Serum blood urea nitrogen (BUN) 24 h after transplantation was 13.8 +/- 5.9 mg/dl, which was significantly higher than before transplantation (6.4 +/- 2.2 mg/dl). There was a positive correlation between the serum BUN and ET-1 (r = 0.62, P < 0.05). An in vitro isometric tension study was performed for the contractility response rate of the intact renal artery in the bath chamber containing the serum of the corresponding recipient animals. The mean contractility response rates were higher with the serum obtained after reperfusion of the graft (66.9 +/- 32.4%) than with those obtained before transplantation (18.3 +/- 9.2%) when compared to a standard contractility rate of 100% with 40 mM KCI. Moreover, these contractility response rates were significantly reduced (32.8 +/- 21.0%) with the addition of the ET-1 receptor antagonist FR139317. The results of the present study demonstrated that the liver transplantation was associated with elevation of ET-1 in the serum of the recipient animals. It was considered that ET-1 in the serum caused a direct vasoconstriction of the renal artery in vitro. This may help to explain the renal dysfunction that is often seen in the recipients of clinical liver transplantation.

Animals↗

22S axonemal dynein is preassembled and functional prior to being transported to and attached on the axonemes.

In an earlier study we reported the isolation of a cytoplasmic dynein from the cytosol of Paramecium multimicronucleatum. In this study we report the isolation and characterization of two cytosolic axonemal dyneins (22S and 12S) as well as a 19S cytoplasmic dynein from the cytosol of whole or deciliated cells using preformed bovine brain microtubules. These three dynein species were characterized according to mass, morphology, vanadate photocleavage patterns, CTPase/ATPase ratios, Km and Vmax values, temperature optima and reactivity with a mAb. For comparison, 22S and 12S axonemal dyneins (ADs) were also isolated and purified from the demembranated axonemes. The 22S and 12S soluble dyneins appear to be related to ciliary ADs in that the 22S soluble dynein is three-headed while the 12S is a one-headed dynein, as determined by negative staining. Ciliary ADs and their corresponding 22S and 12S soluble dyneins isolated from the cytosol also have similar Km and Vmax values as well as vanadate photocleavage patterns and temperature optima. A mAb raised against the soluble 22S dynein reacted with the 22S ciliary dyneins but not the 12S axonemal or the 19S cytoplasmic dynein. All isolated dyneins supported similar microtubule gliding rates but had different ionic requirements for the translocation buffer. These results suggest that: (i) the two soluble 22S and 12S dyneins are precursor molecules of the ciliary dyneins, (ii) the subunits of the outer arm dynein are already assembled in the cytosol as a three-headed bouquet, and (iii) the 22S and 12S soluble dyneins are functional prior to being transported and attached to the axonemes of the cilia.

Animals↗

A case of cytomegalovirus mononucleosis associated with pleural effusion.

A 5 year old boy had a spiky fever accompanied by a mild pharyngitis, cervical lymphadenopathy and hepatosplenomegaly. Laboratory findings revealed leukocytosis with 26% atypical lymphocytes, and liver dysfunction. A chest X-ray showed pneumonia and a considerable amount of pleural effusion. Serum antibody titers for cytomegalovirus (CMV) were elevated significantly and CMV-DNA (polymerase chain reaction) was detected in the pleural effusion. Only 13 cases of pleural effusion associated with infectious mononucleosis have been reported previously in the literature, but there was no documentation that proved CMV infection. The case reported here suggests that the pleural effusion was caused by the infiltration of mononuclear cells to the pleura as a result of systemic inflammation, and the possible alternative of host immune response against CMV was related to recent Varicella zoster virus infection.

Antibodies, Viral↗

[Anesthetic management of a patient with mild hypothyroidism].

A patient with mild hypothyroidism underwent a repair of abdominal aortic aneurysm. Although the serum TSH level of this patient was very high and T4, free T4 levels were low, T3 level remained within normal ranges. Inhalation anesthesia with continuous epidural block was selected and there was no complication such as hypotension or hypothermia during perioperative period. Recently, several reports demonstrate that the preoperative supplemental therapy of the thyroid hormone should not be necessary in the case of mild hypothyroidism. Moreover, the biological potency of T3 is higher than that of T4. Thus, in patients whose T3 level is kept within normal ranges even if serum T4 level is low and serum TSH level is high, we may say that they are in euthyroid state. We think these patients can be anesthetized safely.

Anesthesia, Epidural↗

Cochlear cytogenesis visualized through pulse labeling of chick embryos in culture.

Cytogenesis in the basilar papilla sensory epithelium of the chicken was investigated through pulse labeling of proliferative cells. Tritiated-thymidine was injected intravenously in chick embryos cultured in petri dishes. All embryos received the injection on the seventh day of incubation (E7), when the progenitors of hair cells and supporting cells are replicating deoxyribonucleic acid (DNA). Cells that were in the synthesis phase of the cell cycle, either at the time of the 3H-thymidine pulse or within 2 hours, incorporated detectable levels of the radioactive DNA precursor. Labeled cells were identified in cochleae from embryos fixed at 0.5, 1, 2, 4, 6, 12 hours, 6 and 8 days after the pulse. One hour after the injection the majority of labeled nuclei were in the basal and middle strata of the sensory epithelium. Four to 6 hours after the injection, a greater number of labeled cells appeared in the lumenal stratum. The patterns of labeled cells in embryos fixed immediately after the injection of 3H-thymidine and in others fixed 6 to 8 days after the injection were unchanged, suggesting that the progenitor cells divide and their progeny differentiate in the sensory epithelium without appreciable transverse migration. Mitotic figures were usually observed only in the lumenal stratum. Analysis of DNA content in the populations of Feulgen-stained nuclei at three levels of depth through the epithelium also produced results consistent with the conclusion that vertical nuclear migration occurs during development of the cells in this sensory epithelium.

Animals↗

The salting-out test to identify virulent Yersinia pseudotuberculosis.

A total of 54 strains including 8 serotypes of Yersinia pseudotuberculosis were examined to find out about their cell surface hydrophobicity and virulence plasmid-associated properties. All the strains which aggregated in 0.9% saline expressed the properties of calcium-dependent growth and autoagglutination. However, the hydrophilic strains did not possess virulence plasmid-associated properties. The above results suggest that the salting-out test with 0.9% saline could be an effective measure to differentiate the virulence plasmid-carrying strains of Y. pseudotuberculosis from those of plasmidless virulence.

Animals↗

[Interaction of midazolam and thiopental in amnestic effect].

Interaction of midazolam and thiopental in amnestic effect was studied in 30 adult patients who underwent elective surgery of lower extremities under epidural or spinal anesthesia in combination with oxygen, nitrous oxide and low concentration of sevoflurane. Combination of midazolam 2.0-3.0 mg (0.041 +/- 0.006 mg.kg-1) and thiopental 3-5 mg.kg-1 produced amnestic effect in 87% of patients. No side effects, such as decrease in O2 saturation, upper airway obstruction, cardiovascular depression and delayed emergence were observed with this small dose of midazolam. Administration of midazolam 2.0-3.0 mg before epidural, or spinal anesthesia in the operating room under observation of anesthesiologists, followed by thiopental 3-5 mg.kg-1, was safe and comfortable to the patients.

Adult↗

Subcellular electrolyte alterations during progressive hypoxia and following reoxygenation in isolated neonatal rat ventricular myocytes.

This study characterizes the sequential alterations of, and relations between, multiple electrolytes in cytoplasm, mitochondria, and whole cells during hypoxia and on reoxygenation in isolated neonatal rat ventricular myocytes. Subcellular electrolyte content and distribution were measured by electron probe x-ray microanalysis, membrane phospholipid degradation by tritiated arachidonic acid release, and cell morphology by electron microscopy. At 1-2 hours of hypoxia, the myocyte population showed a loss of cytoplasmic potassium, magnesium, and chlorine without alteration of cytoplasmic sodium or calcium. Mitochondria showed increased potassium with unchanged magnesium content. There was no morphological evidence of cell injury or tritiated arachidonic acid release. At 3-5 hours of hypoxia, the myocyte population showed a further loss of cytoplasmic potassium and magnesium and an increase in cytoplasmic sodium, chlorine, and calcium. At a single-cell level, the increase in cytoplasmic sodium preceded the increase in cytoplasmic calcium. Mitochondria showed increased sodium and chlorine and decreased magnesium before increased calcium content; potassium loss was manifest only at 5 hours of hypoxia. At 3-5 hours of hypoxia, there was also tritiated arachidonic acid release and morphological evidence of cell injury. Reoxygenation for 1 hour after 5 hours of hypoxia partially reversed the mean alterations of all electrolytes, except calcium, in the cytoplasm of the myocyte population, whereas analysis was required at a single-cell level to show a partial reversal in calcium levels in cytoplasm of reoxygenated cells. Reoxygenation for 1 hour after 5 hours of hypoxia partially reversed the mean alterations of all electrolytes, including calcium, in the mitochondria of the myocyte population. Recovery of potassium in the cytoplasm correlated with reduction of mitochondrial calcium content on reoxygenation and best predicted recovery of cellular homeostasis of sodium, chlorine, magnesium, and calcium. This study demonstrates that in this experimental model of hypoxia 1) initial losses of cytoplasmic potassium and magnesium occur in the absence of cell injury; 2) increases of sodium, chlorine, and calcium occur in association with cell injury, with sodium increasing before calcium; 3) membrane phospholipid degradation and electrolyte derangement, including increased calcium, may contribute to reversible and irreversible phases of cell injury; 4) analysis of calcium at a subcompartmental level and at a single-cell level is required to correlate reduction of calcium on reoxygenation with recovery of cell homeostasis; 5) reduction of calcium content in mitochondria may predict recovery of cell homeostasis; and 6) recovery of potassium on reoxygenation best predicts recovery of cell membrane function and cell homeostasis.

Animals↗

[Evaluation of the timing principle with vecuronium].

We evaluated the usefulness of the timing principle with vecuronium in 60 patients who underwent elective surgery, and divided into two groups according to the dose of vecuronium (0.15 and 0.2 mg.kg-1). First, we studied the interval between vecuronium and thiopental administration in 40 patients. The time after vecuronium administration to onset of clinical muscle weakness was 57.6 +/- 7.8 sec in 0.15 mg.kg-1, and 42.2 +/- 2.2 sec in 0.2 mg.kg-1 group. Then, we made and examined the protocol of the timing principle for the rapid tracheal intubation. Induction of anesthesia with 4-5 mg.kg-1 thiopental was done 40 sec after 0.15 mg.kg-1 in 10 patients, and 30 sec after 0.2 mg.kg-1 vecuronium administration in 10 patients. Intubating conditions were almost excellent 70 sec after thiopental administration. In our study, there were no patients who experienced discomfort during induction. We conclude that the timing principle with vecuronium is useful for rapid-sequence tracheal intubation.

Adult↗

[Pharmacokinetic and clinical studies on meropenem].

Pharmacokinetic and clinical studies on meropenem (MEPM, SM-7338), a new developed carbapenem, were performed and the following results were obtained. 1. Absorption/excretion: Pharmacokinetics of MEPM was studied in 9 children using doses of 10 mg/kg and 20 mg/kg by a 30 minute-drip infusion. Peak plasma levels and plasma half-lives of the 2 doses were 28.4 and 43.0 micrograms/ml, and 0.70 and 0.80 hours, respectively. Their urinary recovery rates were 42.5 to 67.6% and 29.9 to 62.6%, respectively. Cerebrospinal fluid levels and penetration rates of MEPM in a patient with purulent meningitis were 0.66 to 4.01 micrograms/ml and 1.6 to 12.2%, respectively. 2. Clinical study: Forty-nine patients were treated with MEPM at doses exceeding 100 mg/kg/day with purulent meningitis and 30 to 60 mg/kg/day with other infections. MEPM gave "excellent" or "good" responses in 48 cases, an efficacy rate of 98.0%. Only one patient with subdural abscess showed fair response. Diarrhea and rash were observed in 1 case each. Abnormal laboratory test results were noted in 5 patients including elevation of GOT, GPT and eosinophils. In no cases the treatment had to be discontinued.

Absorption↗