Biomedical subjects

M Mukai

Publications and source records attributed to M Mukai.

At least 109 records · Page 6Linked to original sources

PubMed1999

[Acute lymphoblastic leukemia with breast infiltration during the second trimester of pregnancy and followed by successful delivery].

A 27-year-old pregnant woman was admitted to a local hospital because of headache, nausea, and general fatigue. Her blood examination showed leukocytosis, anemia, and thrombocytopenia. She was referred to our hospital in March 1998. Her bone marrow was normocellular with an excess of blasts (89.1%, peroxidase stain(-), PAS stain(-)) that displayed a positive immunophenotype for CD2, CD4, CD5, CD7, CD34, CD38, and CD71. Chromosome analysis revealed complex abnormal karyotypes. The patient was given a diagnosis of acute lymphoblastic leukemia associated with central nervous system and breast infiltration, and received induction chemotherapy during the second trimester of her pregnancy. After she achieved complete remission, a cesarean section was performed, and a healthy baby delivered. Our experience in this case demonstrated that combination chemotherapy during the second trimester of pregnancy is feasible.

Adult↗

PubMed1999

[CD30-positive anaplastic large cell lymphoma of bone treated with autologous peripheral blood stem cell transplantation].

A 30-year-old man was admitted to our hospital with the chief complaints of fever and pain in the right shoulder, axilla, and inguinocrural region. Computed tomography, magnetic resonance imaging, 67Ga-scintigraphy, and bone-scintigraphy revealed osteolytic lesions in the ribs and right ilium. Biopsy specimens from lesions in the right ilium confirmed the diagnosis of CD 30-positive anaplastic large cell lymphoma. The patient was treated with 6 courses of CHOP therapy followed by high-dose chemotherapy and autologous peripheral blood stem cell transplantation. He achieved and remained in remission with no evidence of relapse 14 months later.

Adult↗

PubMed1999

Laparoscopically assisted bowel resection for primary mucosa-associated lymphoid tissue lymphoma of the cecum.

We present the first report of laparoscopic resection for colorectal mucosa-associated lymphoid tissue (MALT) lymphoma. A 76-year-old man was found to have MALT lymphoma of the cecum during colonoscopy. He underwent a laparoscopically assisted ileocecal resection after admission and was discharged 9 days postoperatively without any complications. Colorectal MALT lymphoma is a rare neoplasm that responds favorably to locally directed therapy, because it tends to remain localized for prolonged periods. Laparoscopic surgery for colorectal MALT lymphoma is considered feasible because it is minimally invasive, making it suitable for treatment of low-grade malignancies, such as MALT lymphoma, which cannot be removed endoscopically.

Aged↗

PubMed1998

Localization of mitochondrial large ribosomal RNA in germ plasm of Xenopus embryos.

In Xenopus, factors with the ability to establish the germ line are localized in the vegetal pole cytoplasm, or germ plasm, of the early embryo [1-3]. The germ plasm of Xenopus, and of many other animal species including Drosophila, contains electron-dense germinal granules which may be essential for germ-line formation [4-5]. Several components of the germinal granules have so far been identified in Drosophila [6-10]. One of these is mitochondrial large ribosomal RNA (mtlrRNA), which is present in the germinal granules (polar granules) during the cleavage stage until the formation of the germ-line progenitors or pole cells [8-9]. MtlrRNA has been identified as a factor that induces pole cells in embryos that have been sterilized by ultraviolet radiation [11]. The reduction of mtlrRNA in germ plasm by injecting anti-mtlrRNA ribozymes into embryos leads to the inability of these embryos to form pole cells [12]. These observations clearly show that mtlrRNA is essential for pole cell formation in Drosophila. Here, we report that mtlrRNA is enriched in germ plasm of Xenopus embryos from the four-cell stage to the blastula. Furthermore, our electron microscopic studies show that this mtlrRNA is present in the germinal granules during these stages. Thus, mtlrRNA is a common component of germinal granules in Drosophila and Xenopus, suggesting that the mtlrRNA has a role in germ-line development across phylogenetic boundaries.

Animals↗

PubMed1998

A role of calcineurin in coreceptor regulation during differentiation of Cd4+Cd8+ T cells.

The immunosuppressant FK506 inhibits thymocyte positive selection. Calcineurin, a FK506-sensitive Ca2+/calmodulin-dependent protein phosphatase, is presumed to be involved in this event without direct evidence. We have previously shown that moderate stimulation of CD4(+)CD8(+) thymocytes with a combination of the calcium ionophore ionomycin and phorbol myristate acetate mimics positive selection events including downregulation of CD8 expression. Moderate stimulation of a CD4(+)CD8(+) T cell line with the same combination of drugs also induced specific downregulation of CD8 expression. FK506 inhibited the CD8 downregulation in both cell types. The T cell line was transfected with an expression vector encoding an active form of calcineurin. The transfectans remained CD4(+)CD8(+), but became CD4(+)CD8(-) or CD4(+)CD8(low) upon stimulation with phorbol myristate acetate alone. The extent of the CD8 downregulation was correlated with the expression level of the mutant calcineurin. These results suggest that the calcium signal for the CD8 downregulation is mainly delivered through calcineurin activation.

Animals↗

PubMed1998

Non-familial olivopontocerebellar atrophy combined with late onset Alzheimer's disease: a clinico-pathological case report.

A 76-year-old woman with olivopontocerebellar atrophy (OPCA) presented with progressive intellectual deterioration. She showed cerebellar ataxia and muscle atrophy and weakness, and gradually developed generalized dementia with visuospatial disturbance. An autopsy revealed numerous senile plaques (SPs), neurofibrillary tangles (NFTs) and neuropil threads particularly in the CA1, subiculum and entorhinal cortex and to a lesser degree in the cerebral neocortex shown by immunostaining and specific silver impregnation techniques. The nucleus basalis of Meynert had numerous NFTs with fibrillary gliosis and neuronal cell loss. The basis pontis was markedly atrophied and the pontine nucleus had severe neuronal depopulation and gliosis. The pontine transverse fibers were demyelinated with their axons being fragmented. The cerebellar white matter was also severely degenerated. The striatum, Onuf's and intermediolateral nuclei of the spinal cord remained unchanged. Ubiquitin immunohistochemistry and Gallyas silver impregnation technique revealed oligodendroglial inclusions in the pontine nucleus, corticopontine tract, cerebral and cerebellar white matter. On double immunostaining of KP1 and ubiquitin, globular neurite SPs encircled by KP1-positive fibrous structures were found in the hippocampus and cerebral neocortex. The curly neurite SPs contained KP1-positive granules. The KP1-positive microglial cells were distributed widely in the cerebral white matter and HLA-DR-positive ones were found around the SPs. The present case showed generalized dementia compatible with Alzheimer's disease (AD) and had a pathologically limbic type of late onset AD. This is the first case where AD affected non-familial OPCA.

Aged↗

PubMed1998

Spontaneous rupture of the stomach in preschool age children: a report of two cases.

The cases of two preschool-age children who suffered spontaneous gastric ruptures are reported herein. The first was a 2-year-old girl with tetralogy of Fallot, transferred to our hospital due to shock. A laparotomy was performed under the diagnosis of gastrointestinal perforation, and two perforations of the posterior wall of the gastric fundus were found. The second case, a 4-year-old girl who had previously experienced an episode of gastric dilatation, was admitted to our department with abdominal distention and vomiting. An abdominal X-ray film revealed a pneumoperitoneum, and an emergency laparotomy was performed, confirming a round rupture in the posterior wall of the stomach. Both patients had a satisfactory postoperative course.

Child, Preschool↗

PubMed1998

[The oxygen transporting capability of neo red cells (NRC) evaluated under total cardiopulmonary bypass].

The oxygen transporting capability of an artificial oxygen carrier NRC was evaluated by employing it as a perfusate for total cardiopulmonary bypass. NRC is a type of liposome encapsulated hemoglobin. It has a particle size of approximately 220 nm, with a hemoglobin concentration of 5.6 g/dl and its P50 is controlled to 45 Torr. Male beagles were used in the experiment. Approximately 80% of the estimated circulatory volume was exchanged with NRC and total cardiopulmonary bypass was initiated. Arterial oxygen tension and carbon dioxide tension were controlled to 400 Torr and 40 Torr respectively. The perfused we heated to 37 degrees C. The rate of flow was altered during the experiment. Oxygen consumption reached a plateau at 9.3 ml/kg/min where oxygen delivery was 14.9 ml/kg/min. At this point the oxygen consumed per gram of hemoglobin from NRC was equivalent to that from dog red blood cells. This indicated that almost an equal amount of oxygen was consumed from NRC in comparison to red blood cells. Regarding oxygen transporting capability, NRC could be considered a candidate for perfusate in cardiopulmonary bypass.

Animals↗

PubMed1998

Intra-abdominal testis with mature teratoma.

Tumors in an undescended testis are rare in children. We report a mature teratoma arising in the intra-abdominal testis (IAT) of a 1-year-old boy. Preoperative laparoscopy revealed a right IAT near the inguinal ring. As the right testis exposed through the inguinal incision seemed to be a neoplastic mass, an orchidectomy was performed. Histologic examination disclosed a mature teratoma. This is a review of seven cases (including the present one) of a prepubertal tumor originating in an IAT. We speculate that the undescended testes did not cause the neoplasia, but were induced by it.

Cryptorchidism↗

PubMed1998

Anemia in patients with colorectal cancer.

Although anemia is one of the signs of colorectal cancer, the relationships between histological findings and hematological findings other than hemoglobin level have not been adequately investigated. We investigated the relationship between hematological findings, serum iron, and histological findings in 358 patients (207 men and 157 women) with colorectal cancer. Their mean (+/-SD) ages were 64.3 +/- 12.4 and 63.8 +/- 13.3 years. A hemoglobin level of less than 10 g/dl was the criterion for anemia, and 20.8% of the men and 25.8% of the women met this criterion. Univariate analysis showed that carcinoma of the cecum, ascending colon, and transverse colon; large-size carcinoma, invasion beyond the proper muscle layer; positive lymph node metastasis: and clinical stage (Dukes' B, C, and D) were factors associated with high incidence of anemia. Histological type did not affect the hematological findings. Multivariate analysis showed that age, tumor site, and tumor size were significant factors related to anemia. Depth of invasion, the presence or absence of lymph node metastasis, and Dukes' classification were not significant factors. In the presence of these factors, mean corpuscular volume and mean corpuscular hemoglobin concentration values were low, and red blood cells were microcytic and hypochromic. The incidence of a low serum iron level was about twice the frequency of a hemoglobin level of less than 10 g/dl. The results of the multivariate analysis showed that none of the factors were significantly related to iron deficiency.

Adenocarcinoma↗

PubMed1998

A new method of evaluating hemorrhoids with the retroflexed fiberoptic colonoscope.

BACKGROUND: The conventional classification of the degree of hemorrhoids does not consider the severity of hemorrhage. The purpose of this study was to establish a new objective method for evaluating hemorrhoids in close relation to the main symptoms, hemorrhage and prolapse, as observed through a retroflexed colonoscope in the rectum. METHODS: The subjects were 531 consecutive patients who complained of symptoms related to the rectum or the anus. The degree of mucosal elevation of the rectal columns, changes in color (the existence and degree of red color sign, dilated vein, and white area), and the existence and size of hypertrophied anal papillae were evaluated by colonoscopy. RESULTS: Red color sign was the finding closely related to hemorrhage (p < 0.0001). Dilated vein, white area, and a large hypertrophied anal papilla were related to prolapse (p < 0.0001). The degree of mucosal elevation of the rectal columns was related to both hemorrhage and prolapse (p < 0.0005, p < 0.05). CONCLUSION: Retroflexing the colonoscope intrarectally facilitated identification of findings in the anal canal related to hemorrhage and prolapse, which are the clinical manifestations of hemorrhoids.

Adult↗

PubMed1998

Palliative radiotherapy for lingual metastasis of renal cell carcinoma.

The report is of a 50-year-old man with renal cell carcinoma (RCC) who had rapidly progressing metastasis to the tongue at 10 months after the left radical nephrectomy. The metastatic lingual tumor was not resectable, therefore treated with radiation (50 Gy). The tumor disappeared macroscopically after the radiation therapy, but enlarged again 4 months later. The patient died of respiratory failure due to multiple lung metastases 12 months after the appearance of the lingual metastasis. Radiation therapy is an acceptable palliative strategy for advanced lingual metastasis of RCC.

Carcinoma, Renal Cell↗

PubMed1998

Down-regulation of focal adhesion kinase, pp125FAK, in endothelial cell retraction during tumor cell invasion.

Although endothelial cell retraction is required before tumor cell invasion, its molecular mechanism still remains obscure. We previously demonstrated that conditioned medium (CM) derived from a human pancreatic cancer cell line, PSN-1, induced endothelial cell retraction and facilitated tumor cell invasion. To investigate the molecular change of events in the transduction of extracellular signals during endothelial cell retraction, we examined the effect of the CM derived from PSN-1 cells on the tyrosine phosphorylation in endothelial cells. Immunoblot analyses revealed that the PSN-1 CM decreased tyrosine phosphorylation of a 120-130 kD protein, and induced the concomitant down-regulation of focal adhesion kinase, pp125FAK, during endothelial cell retraction in time- and dose-dependent fashions. These changes preceded endothelial cell retraction and were reversible after removal of the CM. Further quantitative densitometric analyses demonstrated that the extent of decrease in tyrosine phosphorylated 120-130 kD protein during the endothelial cell retraction was likely to be proportional to that of the down-regulation of pp125FAK. A tyrosine phosphorylated 120-130 kD protein immunoprecipitated by anti-phosphotyrosine antibody immunoreacted with anti-pp125FAK antibody. These results suggested that decreased amount of a tyrosine phosphorylated 120-130 kD protein probably due to the down-regulation of pp125FAK might be associated with the signal transduction pathway in the endothelial cells during their retraction. Furthermore, these findings were also observed in the CM from another four human cancer cell lines, suggesting the down-regulation of pp125FAK in endothelial cells during tumor cell invasion.

Animals↗

PubMed1998

Experimental assessment of endoscopic mucosectomy with a cap-fitted panendoscope.

BACKGROUND AND STUDY AIMS: The use of a cap-fitted panendoscope is one method of carrying out endoscopic mucosectomy in the esophagus, stomach, and large intestine. The purpose of this study was to determine the optimal volume of physiological saline for submucosal injection, the rate of mucosal extension after saline injection, the initial size of the resected mucosal specimen, and the most appropriate heights for the fitted caps used in the colon and in the rectum, respectively. METHODS: Endoscopic mucosectomies using cap-fitted panendoscopes were carried out on resected surgical specimens from ten patients with colorectal cancer. RESULTS: It was necessary to inject 12 ml of saline under the mucosa to prevent perforation. Submucosal saline injection extended the mucosa by 1.4 +/- 0.2 times. A cap with a height of 7 mm is suitable for performing mucosectomy in the colon safely, while both 7 mm and 10 mm caps can be used in the rectum. The initial size of the resected mucosal specimens obtained with both caps was 12-20 mm (mean 14 mm) in diameter, with no significant differences. As the sizes of resected mucosal specimens reported in the past have been obtained after submucosal saline injection, it appears that larger specimens can be resected with the cap-fitted panendoscope than with conventional methods. CONCLUSIONS: The conditions under which endoscopic mucosectomy using the cap-fitted panendoscope can be performed safely in the colon and the rectum were suggested by this experimental study using resected specimens. A saline injection of 12 ml under the mucosa is necessary to prevent perforation. A cap with a height of 7 mm is the most suitable size for the colon, while both 7 mm and 10 mm caps can be used in the rectum.

Biopsy, Needle↗

PubMed1998

Multiple smooth muscle tumors arising in deep soft tissue of lower limbs with uterine leiomyomas.

A 40-year-old woman had multiple smooth muscle tumors in the left inguinal region, the bilateral thighs, the omentum, the peritoneum, and the right infundibulum pelvic ligament associated with uterine leiomyomas. She had a history of uterine leiomyomas, which were resected 13 years ago. Histopathologic evaluation revealed tumor masses composed of smooth muscle cells with relatively low cellularity, which were consistent with a diagnosis of leiomyoma. Tumor necrosis and nuclear atypia were absent. Mitotic figures were very scarce (less than 1 mitotic figure per 10 high-power fields). Immunohistochemical evaluation revealed a positive reaction of the tumor cells to muscle markers, estrogen receptors, and progesterone receptors. No pulmonary lesion was found. Similar instances of uterine leiomyomas with histologically benign extrauterine smooth muscle tumors have been reported. This curious condition has been referred to as "benign metastasizing leiomyoma," in which most of the reported cases involve the lungs. The distribution of extrauterine tumors in our case is very unusual and may be the first case with multiple leiomyomas in deep soft tissue of the limbs. Consideration was given to the concept that these may be of multifocal origin, rather than metastases.

Adult↗

PubMed1998

Mechanism of membrane damage by Clostridium perfringens alpha-toxin.

The effect of Clostridium perfringens alpha-toxin on liposomes prepared from phosphatidylcholine (PC) containing the fatty acyl residues of 18 carbon atoms was investigated. The toxin-induced carboxyfluorescein (CF) leakage and phosphorylcholine release from multilamellar liposomes increased as the phase transition temperature of the phosphatidylcholines containing unsaturated fatty acyl residues decreased. However, there was no difference between the sensitivity of the different phosphatidylcholines solubilized by deoxycholate to the phospholipase C (PLC) activity of the toxin. However, the toxin did not hydrolyze solubilized distearoyl-L-alpha-phosphatidylcholine (DSPC) or phosphatidylcholine containing saturated fatty acyl residue, and caused no effect on liposomes composed of DSPC. These results suggest that the activity of the toxin is closely related to the membrane fluidity and double bond in PC. The N-terminal domain of alpha-toxin (AT1-246) and variant H148G did not induce CF leakage from liposomes composed of dioleoyl-L-alpha-phosphatidylcholine (DOPC). H148G bound to the liposomes, but AT1-246 did not. However, the C-terminal domain (AT251-370) conferred binding to liposomes and the membrane-damaging activity on AT1-246. These observations suggest that the membrane-damaging action of alpha-toxin is due to the binding of the C-terminal domain of the toxin to the double bond in the PC in the bilayer and hydrolysis of the PC by the N-terminal domain.

Bacterial Toxins↗

PubMed1998

Efficacy of L-846 in patients with insomnia: evaluation by polysomnography.

The effects of L-846, an ultra-short-acting pyrazolopyrimidine hypnotic, on sleep were studied in nine insomniacs and two neurotic patients with insomnia. The patients were randomly assigned to receive 5 mg (n=6) or 10 mg (n=5) L-846. The study schedule comprised of one adaptation night, two baseline nights, three drug nights, and two withdrawal nights. Sleep latency and slow wave sleep (SWS) latency was largely shortened and %SWS increased in the early phase of sleep. No clear evidence of rebound insomnia was noted.

Acetamides↗

PubMed1998

Circadian rhythms of hormone concentrations in alcohol withdrawal.

We investigated the circadian rhythm of hormones (cortisol, melatonin) in alcoholic patients during and 1 month after alcohol withdrawal. Patients with delirium tremens had irregular serum hormone concentration rhythms during withdrawal, which normalized after the withdrawal period. Patients without delirium tremens had normal circadian rhythms even during the withdrawal period. We speculated that the disturbance of the biological oscillator, in terms of the decline of synchronizing function or the decrease in synchronizing factors, caused abnormal circadian rhythms of hormone release during delirium tremens.

Adult↗