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Biomedical subjects

M Mukai

Publications and source records attributed to M Mukai.

At least 73 records · Page 4Linked to original sources
PubMed2000

Pancreatoblastoma. Three original cases and review of the literature.

PURPOSE: To describe the characteristics of pancreatoblastoma. MATERIAL AND METHODS: We studied 3 cases of pancretoblastoma and reviewed another 59 cases. Parameters analyzed were tumor site, hemorrhage, capsule formation, necrosis, vascularity, production of alpha-fetoprotein (AFP), cystic changes and calcification. RESULTS: The diagnostic findings were as follows: pancreatic head origin (24/54, 44%), pancreatic body and tail origin (30/54, 56%), hemorrhage (16/17, 94%), capsule formation (24/26, 92%), necrosis (28/31, 90%), hypervascularity (10/14, 71%), production of AFP (19/28, 68%), cystic changes (11/16, 69%), and calcification (10/21, 48%). All neonatal cases demonstrated cystic changes. Three of them were patients with Beckwith-Wiedmann syndrome. The incidence of capsule formation and calcification was not related to the origin of the tumor. CONCLUSION: The most common features of pancreatoblastoma are hemorrhage, capsule formation and necrosis.

Child↗
PubMed2000

Effects of a selective inhibitor of Na+/Ca2+ exchange, KB-R7943, on reoxygenation-induced injuries in guinea pig papillary muscles.

The effects of a novel agent that is reported to selectively block Ca2+ influx by Na+/Ca2+ exchange (NCX), KB-R7943, on the reoxygenation-induced arrhythmias and the recovery of developed tension after reoxygenation, were investigated in guinea pig papillary muscles. KB-R7943 dose-dependently suppressed the contracture tension during low-sodium (21.9 mM) perfusion (23+/-8% of steady-state developed tension at 10 microM vs. 56+/-11% in control; n = 6, p<0.05), but did not change action potential and contractile parameters. During the reoxygenation period after 60-min substrate-free hypoxia, KB-R7943 (10 microM) significantly decreased the incidence of arrhythmias (44 vs. 100% in control; n = 9, p <0.05) and shortened the duration of arrhythmias (16+/-11 vs. 72+/-14 s; p<0.01). KB-R7943 (10 microM) significantly enhanced the recovery of developed tension after reoxygenation (83+/-4 vs. 69+/-3% in control; p<0.05). We conclude that KB-R7943 (10 microM) selectively inhibits the reverse mode of NCX, and that it attenuates reoxygenation-induced arrhythmic activity and prevents contractile dysfunction in guinea pig papillary muscles. These results suggest that Ca2+ influx by NCX may play a key role in reoxygenation injury.

Action Potentials↗
PubMed2000

Role of tryptophan-1 in hemolytic and phospholipase C activities of Clostridium perfringens alpha-toxin.

Replacement of the Trp-1 in Clostridium perfringens alpha-toxin with tyrosine caused no effect on hemolytic and phospholipase C (PLC) activities or on binding to the zinc ion, but that of the residue with alanine, glycine and histidine led to drastic decreases in these activities and a significant reduction in binding to the zinc ion. The hemolytic and PLC activities of W1H and W1A were significantly increased by the preincubation of these variant toxins with zinc ions, but the preincubation of W1G with the metal ion caused little effect on these activities. Gly-Ile-alpha-toxin, which contained an additional Gly-Ile linked to the N-terminal amino acid of alpha-toxin, did not show hemolytic activity, but showed about 6% PLC activity of the wild-type toxin. A mutant toxin, which contained an additional Gly-Ile linked to the N-terminus of a protein lacking 4 N-terminal residues of alpha-toxin, showed about 1 and 6% hemolytic and PLC activities of the wild-type toxin, respectively. Incubation of the mutant toxin with zinc ions caused a significant increase in PLC activity. These observations suggested that Trp-1 is not essential for toxin activity, but plays a role in binding to zinc ions.

Clostridium perfringens↗
PubMed2000

Y-27632, an inhibitor of rho-associated protein kinase, suppresses tumor cell invasion via regulation of focal adhesion and focal adhesion kinase.

Migration of rat ascites hepatoma (MM1) cells, invasion and phagokinetic movement were induced by the combination of lysophosphatidic acid (LPA) and fibronectin (FN). Induction of migratory activity was tightly correlated with morphological change of MM1 cells from spherical or polygonal-shaped cells to fusiform-shaped ones with pseudopodia. MM1 cells were mobile in a fusiform shape, whereas those of a spherical or polygonal shape were not. A small GTPase Rho and one of its downstream effectors ROCK (Rho-associated coiled-coil forming protein kinase), play essential roles in these processes, as evidenced by suppression of migration and morphological change of MM1 cells by Clostridium botulinum C3 exoenzyme, an inhibitor of Rho, or by Y-27632, an inhibitor of ROCK. Y-27632 also suppressed the formation of fusiform-shaped pseudopodia-carrying MM1 cells that was induced by stimulation with the combination of LPA and FN. LPA and FN also evoked the formation of focal adhesions and actin bundles, and tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin. The inhibitory effect of Y-27632 on LPA-induced migration and morphological change of MM1 cells was considered to be mediated, at least in part, by impaired formation of focal adhesions and actin bundles. Y-27632 suppressed LPA-induced tyrosine phosphorylation of FAK and paxillin, suggesting that ROCK regulates these molecules and Y-27632 inhibits cellular migration and morphological change, at least in part, through this regulation.

Actins↗
PubMed2000

Reciprocal functions of liver tumor cells and endothelial cells. Involvement of endothelial cell migration and tumor cell proliferation at a primary site in distant metastasis.

BACKGROUND: The mechanism by which tumor cells interact with endothelial cells at the primary site in metastasis remains obscure. MATERIALS AND METHODS: To disclose the precise mechanisms and processes of metastasis and angiogenesis, we investigated the interactions of endothelial cells (CPAE; calf pulmonary arterial endothelial cells) with two mouse liver tumor cell lines, G-5, a highly metastatic clone, and G-1, a poorly metastatic clone, based on the difference in their angiogenic activities in vivo at a primary site. RESULTS: G-5 cell cultured conditioned medium (CM) promoted migration of endothelial cells more than did G-1 cell CM, in migration assay using modified Boyden chambers. Anti-basic FGF antibody inhibited G-5-induced endothelial cell migration. Furthermore, endothelial cells stimulated proliferation of G-5 cells more than that of G-1 cells in coculture assay using Transwell chambers (pore size; 0.4 microm). Pretreated endothelial cells with bFGF enhanced tumor cell proliferation, suggesting the ability of activated endothelial cells to support tumor growth. In addition, incubation with endothelial cell CM also improved the proliferative activity of G-5 cells more than that of G-1 cells in a concentration-dependent fashion, indicating production and secretion of liver tumor cell growth substance by endothelial cells. CONCLUSION: These results provide evidence that liver tumor cells stimulate endothelial cell migration and migrated endothelial cells facilitate liver tumor cell proliferation. Tumor growth at a primary site may initially be dependent on migrated endothelial cells rather than vascularization or blood nutrient supply. This bi-directional paracrine relationship between liver tumor cells and endothelial cells may influence their metastatic ability.

Animals↗
PubMed2000

Liver dysfunction due to apoptosis in a patient with systemic lupus erythematosus.

We report on a 23-year-old Japanese female with a 13-year history of systemic lupus erythematosus (SLE), and two episodes of deterioration followed by treatment with high dose prednisolone. Although she had been recently treated with prednisolone (12.5 mg daily), her liver function became worse in July 1998. Results of a liver biopsy revealed multi-focal hepatic cell death in a severe fatty liver, without any inflammatory cell invasion. The biopsy also showed a positive TUNEL (Tdt-catalysed DNA nick end labelling) reaction indicating apoptosis. Her liver function recovered rapidly following steroid pulse therapy. Serum soluble Fas ligand (sFasL) was found to be elevated to a concentration of 0.395 ng/ml at the time of liver damage, but was less than 0.03 ng/ml before liver damage and after prednisolone treatment. The liver damage in this case appeared to be involved with apoptosis induced by sFasL. Although hepatitis associated with SLE is rare, apoptosis directly related to elevated sFasL levels might cause this complication.

Adult↗
PubMed2000

Primary osteosarcoma of the sphenoid bone with extensive periosteal extension--case report.

A 28-year-old male presented with a primary osteosarcoma of the sphenoid bone with extensive periosteal extension manifesting as severe headache and right exophthalmos. Computed tomography (CT) and magnetic resonance imaging revealed an anterior middle cranial fossa tumor extending into both the orbit and the extracranial space. However, roentgenography and CT with bone windows showed no marked osteolytic changes of the sphenoid bone. Total removal of the tumor was performed via the orbitozygomatic approach. Surgery revealed that the tumor had extended periosteally without macroscopic bone destruction, but no obvious abnormalities of the skull. The histological diagnosis was osteosarcoma. The patient was treated with chemotherapy and radiation therapy, but died of tumor recurrence 10 months after the surgery.

Adult↗
PubMed2000

Quantitation of macrophage migration inhibitory factor (MIF) using the one-step sandwich enzyme immunosorbent assay: elevated serum MIF concentrations in patients with autoimmune diseases and identification of MIF in erythrocytes.

We raised monoclonal antibodies against human macrophage migration inhibitory factor (MIF), and developed a one-step sandwich enzyme-linked immunosorbent assay (ELISA) method highly specific for human MIF. The ELISA system utilizes a solid phase monoclonal antibody as a capture antibody and a horseradish peroxidase-conjugated monoclonal antibody as a detector antibody. We used this ELISA method to evaluate the serum level of MIF in 240 healthy volunteers (140 males and 100 females). We found no significant difference in MIF concentration with respect to age. A significant difference was found with respect to sex, with the mean value (+/- SD) for male subjects of 5.3+/-2.3, and that for female subjects of 4.6+/-2.3 ng/ml (p<0.05). We next measured the serum MIF contents of patients with autoimmune diseases, and found that MIF levels were significantly elevated in patients with systemic lupus erythematosus and rheumatoid arthritis, 20.0+/-11.0 ng/ml and 21. 7+/-11.2 ng/ml, respectively. Using anti-MIF antibody-immobilized sepharose column chromatography, we discovered for the first time that MIF was present in erythrocytes. Taken together these results suggest that MIF plays a major role in autoimmune diseases and, moreover, potentially induces various patho-logical outcomes in cases of hemolytic disorders.

Adult↗
PubMed2000

[Perforation of small intestinal during hematologic recovery in an elderly man after induction therapy for acute lymphoblastic leukemia L3].

A 67-year-old man with a 7-month history of dilated cardiomyopathy was admitted to our hospital because of general fatigue, shortness of breath, and anemia on laboratory examination. Increased blasts were observed in the bone marrow. The blasts were characterized by large cells with abundant, intensely basophilic, vacuolated cytoplasm, round nuclei, and prominent nucleoli. Chromosome analysis revealed a nonrandom t(8;22)(q24;q11) chromosomal abnormality, and surface-marker analysis disclosed a positive immunophenotype for CD10, CD19, CD20, CD38, HLA-DR, FMC7, and IgM-lambda. These findings yielded a diagnosis of L3 acute lymphoblastic leukemia. The patient was treated with chemotherapeutic agents. On the 39th hospital day, during hematologic recovery after induction therapy, abdominal pain developed. Abdominal X-ray films disclosed ileus with dilatation of the small bowel and Kerckring's folds. Conservative treatment was begun but the patient died. At autopsy, intestinal perforations were observed at a site 55 cm proximal to the ileocecal junction. A specimen of perforated tissue revealed a diffuse infiltration of leukemic cells through the small bowel wall. However, bone marrow specimens showed no signs of aggravation of leukemia.

Aged↗
PubMed2000

[Necessity of permanent anticoagulant therapy for isolated mitral valve replacement with bioprosthetic heart valve to prevent the postoperative thromboembolic complications].

One hundred fifty four patients underwent isolated mitral valve replacement with bioprosthetic heart valve at Hyogo Medical College Hospital from November 1973 to December 1998. A porcine bioprosthetic valve was replaced in 82 patients (Hancock 43, Carpentier-Edwards 26, Hancock II 13) and pericardial bioprosthetic valve in 72 patients (Ionescue-Shiley 39, Carpentier-Edwards 33) with a mean follow-up of 1,410 patients-years. Their thromboembolism rates were also analyzed in linear and actuarial term over the 15-year period. The incidence of thromboembolism rate was 2.5%/pt.yr. Thromboembolic free rates for patients with anticoagulant therapy were significantly decreased for patients without therapy. Thromboembolic free rates for patients with atrial fibliration were also were significantly decreased for patients with sinus rhythm because the patients with sinus rhythm were not on anticoagulant therapy. In conclusion, it is necessary for the all patients to be on anticoagulant therapy after mitral valve replacement with bioprosthetic valves, even though patients with sinus rhythm.

Adult↗
PubMed2000

[The validity of the sentinel node concept in gastrointestinal cancers].

Although the sentinel node concept has been validated and clinically applied to breast cancer and malignant melanoma, its clinical significance in other solid tumors has not been thoroughly investigated. With regard to gastrointestinal (GI) cancers in particular, our surgeons have been cautious because of the high frequency of skip metastasis and the complicated lymphatic system in the GI tract. We would like to emphasize that so-called skip metastasis has been defined according to anatomic classification of regional lymph nodes and that the lymphatic drainage route must be patient or lesion specific. To test the validity and feasibility of this concept in GI cancers, we have established a radio-guided intraoperative sentinel node navigation system using preoperative endoscopic submucosal injection of radioactive tracer followed by intra-operative gamma-probing. In 131 patients with GI cancers (esophagus: 22, stomach: 71, colorectum: 38), the detection rate of sentinel nades was 91% and overall diagnostic accuracy of lymph node metastasis by sentinel node status was 97%. Initial results suggest further investigation of this procedure as an accurate staging and a minimally invasive approach to early GI cancers.

Gastrointestinal Neoplasms↗
PubMed2000

[MRI of ductal carcinoma in situ of the breast: patterns of findings and evaluation of disease extent].

Ten cases of ductal carcinoma in situ (DCIS) or DCIS with microinvasion were reviewed in order to evaluate the characteristic findings of DCIS and to evaluate the extent of disease on MRI. A 1.5Tesla Signa or Horizon (GE Medical Systems) unit was used with a dedicated receive-only breast coil. The pulse sequence based on RARE was used with the fat suppression technique. After examining both breasts with a large FOV (30 cm), the affected breast alone was examined with a smaller FOV (18 cm) and larger matrix (512 x 384) with and without Gd-enhancement. DCIS showed several types of findings on MRI: linear, spotty enhancement; gathering of linear enhancement; enhanced area or mass without distortion of the surrounding tissue; and well-circumscribed mass mimicking intraductal papilloma. Compared with typical findings of invasive carcinoma, DCIS tended to be enhanced slowly. After performing MR examination in addition to mammography and ultrasonography, a more accurate diagnosis of disease extent was possible in 6 of 10 patients. MRI was useful in providing more precise information on the disease extent of DCIS, and it is considered useful in planning the type of surgery. Further study using larger series and precise pathological correlations are necessary.

Adult↗
PubMed2000

[Two cases of classical polyarteritis nodosa associated with a low titre of MPO-ANCA].

We studied two autopsy cases, each with a low titre of myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) associated with systemic vasculitis. It was difficult to distinguish these cases from classic polyarteritis nodosa. The patients had suffered from continuous fever, malaise, and weight loss: however, their renal insufficiency was clinically mild over the course of their disease. The patients were diagnosed initially as having MPO-ANCA-associated vasculitis and were treated with prednisolone. Their clinical status improved, but unfortunately, they died of an infectious disease. Autopsies revealed systemic vasculitis in small arteries with no signs of necrotizing and crescentic glomerulonephritis. Our pathologist subsequently diagnosed both cases as classic polyarteritis nodosa. Systemic vasculitis associated with MPO-ANCA is usually considered to be a microscopic polyarteritis. However, classic polyarteritis nodosa should always be considered as a possibility for those patients with mild renal insufficiency and a low titre of MPO-ANCA.

Aged↗
PubMed2000

Laparoscopic wedge resection of gastric submucosal tumors.

Minimally invasive surgery has revolutionized the treatment of gastrointestinal tumors. Submucosal tumors (SMTs) of the stomach can be resected using laparoscopic techniques. Between 1993 and 1997, laparoscopic wedge resection was performed in 34 patients with an SMT of the stomach. The tumors ranged from 8 to 60 mm in diameter. All surgical margins were clear. The average operative time was 131 minutes. Most of the patients began eating on the first postoperative day and were discharged within 5 to 7 days. Histopathologic examination of the tumors showed gastrointestinal stromal tumor (n = 14), ectopic pancreas (n = 7), leiomyosarcoma (n = 4), schwannoma (n = 3), carcinoid (n = 2), leiomyoma (n = 2), an inflammatory lesion caused by parasites (n = 1), and cyst (n = 1). No recurrences were observed over the 5-year follow-up period. A solid SMT of the stomach larger than 20 mm in diameter can be treated using laparoscopic wedge resection.

Adult↗
PubMed2000

[Malignant solitary fibrous tumor of the pleura: two cases and review of the literature].

We present two cases of malignant solitary fibrous tumor of the pleura (MSFT-P) and review 29 reported cases of MSFT-P. In examining the clinical and morphological features and prognosis of MSFT-P, we found that over 90% of the patients had some symptoms and one-third showed local recurrence. Chest radiographs and CT demonstrated large broad-based masses with necrosis, hemorrhage, and pleural effusion. The maximum diameter of the tumors was greater than 10 cm. Pleural effusion was seen in more than 70% of the patients, but there was only one case of pleural dissemination. All of the cases were well demarcated, and this was the most reliable finding for differentiating MSFT-P and malignant mesothelioma.

Aged↗
PubMed2000

Reducing the volume of polyethylene glycol electrolyte lavage solution to less than 2 liters for bowel preparation.

Smaller volumes of polyethylene glycol electrolyte lavage solution (PEG), an oral whole-bowel irrigation solution employed in colorectal preparation, were given to patients to decrease the discomfort associated with pretreatment. Comparison was made between groups receiving standard and modified preparations. A total of 68 patients (gastrointestinal surgery: 55; total colonoscopy: 13) were enrolled in the study. The mean volume of PEG used was significantly smaller in the modified than in the standard preparation (1,694 ml vs. 2,735 ml, p<0.01). In addition, the mean PEG administration period was significantly shorter for the modified preparation (183 min vs. 237 min, p<0.05). However, the mean PEG excretion time and the number of bowel movements were not significantly different between the two groups. There was also no significant difference between the two groups in terms of the efficacy, safety, usefulness, or tolerability of the preparations. These results suggest that it is possible to reduce the PEG volume by more than 1 L to alleviate patient discomfort without a significant loss of efficacy. The modified method is useful for preparing the large bowel for either gastrointestinal surgery or total colonoscopy.

Colonoscopy↗