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Biomedical subjects

M Iwasaki

Publications and source records attributed to M Iwasaki.

At least 163 records · Page 9Linked to original sources
PubMed1998

Changes in phenytoin concentrations in blood and cerebrospinal fluid caused by direct hemoperfusion in a patient intoxicated with phenytoin.

We performed direct hemoperfusion (DHP) 5 times on a patient with consciousness disorder and phenytoin intoxication. We then measured the phenytoin concentrations in her cerebrospinal fluid (CSF) and blood at various times. After the first DHP session, consciousness began to improve, and it normalized after the fourth DHP session when the blood concentration of phenytoin had decreased from 54.0 microg/ml to 16.5 microg/ml. The average plasma phenytoin elimination rate of DHP was 18.0% over 120-180 min. The concentration of phenytoin in the CSF decreased as that in the blood was lowered by DHP. The average reduction rate of phenytoin in the CSF after a DHP session was 23.7%, which was similar to the rate of elimination from the blood. The CSF/blood phenytoin ratio was 0.17, and no marked changes were detected before or after a DHP session.

Acute Disease↗
PubMed1998

Band 3 Tokyo: Thr837-->Ala837 substitution in erythrocyte band 3 protein associated with spherocytic hemolysis.

We report a case of spherocytosis associated with erythrocyte band 3 deficiency. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of erythrocyte membrane proteins showed that the patient's band 3 was reduced to about 80% of the control level. Molecular analysis revealed that this quantitative alteration was accompanied by a novel base change at codon 837 (ACG-->GCG) of the AE1 gene, resulting in substitution of alanine for threonine. In bone marrow mononuclear cells, both mutant and wild-type mRNA were comparably detected, suggesting that this mutation interfered with band 3 processing or assembly, leading to impaired accumulation of mutant band 3 in the plasma membrane.

Adult↗
PubMed1998

Improvement of a mouse feeder for chemical toxicology testing.

A mouse feeder in common use in the US was modified to eliminate spillage, contamination by excreta and formation of food aggregates. The improved feeder consists of a glass jar which holds 100 g of meal-type feed, an inner metal mesh tube, a marble placed inside the inner mesh tube, and a snap-on metal lid. Female mice [B6C3F1 and CD-1(ICR)] were housed 5 animals/cage. Only slight contamination by feces, but not by urine, was observed in a 13-week feeding study with Japanese meal-type food and the improved feeder. Food spillage also decreased. Food consumption was significantly higher in cages with the conventional Japanese feeder than in the improved one, but no difference was observed between the two feeders in body weight gain.

Animal Feed↗
PubMed1998

Long-term follow-up results of laminectomy for cervical myelopathy caused by ossification of the posterior longitudinal ligament.

OBJECT: This retrospective study was performed to assess the long-term results of cervical laminectomy in treating ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. METHODS: The authors reviewed medical records in 44 of 52 patients who underwent cervical laminectomy between 1970 and 1985 (mean follow up 14.1 years). The neurological recovery rate after laminectomy was 44.2% after 1 year and 42.9% after 5 years. The surgical outcome was maintained after 5 years but worsened between 5 and 10 years postsurgery: the recovery rate at the last follow-up review was 32.8%. Using multivariate stepwise analysis, the preoperative factors that affected clinical results were found to be the age at operation, the severity of preexisting myelopathy, and a history of trauma. Late neurological deterioration was observed in 10 (23%) of 44 patients. The earliest deterioration occurred at 1 year and the latest was at 17 years postsurgery (mean 9.5 years). The most frequent cause of deterioration was trauma due to a fall (six patients), followed by ossification of the ligamentum flavum (three patients). Postoperative spread of the OPLL was noted in 70% of the patients, but it was clearly the cause of neurological deterioration in only one of them. After laminectomy, postoperative progression of kyphotic deformity was observed in 47% of patients, but these changes did not cause neurological deterioration. CONCLUSION: The authors recommend early surgical decompression for OPLL because the outcome is better for younger patients and for those with a higher score as measured by the Japanese Orthopedic Association's system.

Accidental Falls↗
PubMed1998

Immunohistochemical properties of lipid peroxidation and prognosis in adenocarcinoma of the lung.

Glutathione-related enzymes are thought to influence the prognoses of patients with adenocarcinoma of the lung. In this study, the localization of these enzymes was examined immunohistochemically in the primary lesions and metastatic lymph nodes of 61 patients with primary adenocarcinoma. Strong immunoreactivity for glutathione peroxidase (GSH-PO) and superoxide dismutase (SOD) was found in tissue from patients with poor prognoses, while tissue from patients with favorable prognoses demonstrated only immunoreactivity for these enzymes. Therefore, believe that glutathione-related enzymes may serve as predictors of tumor resistance in patients with adenocarcinoma, hence measuring these enzymes may be useful in determining the need for adjuvant therapy.

Adenocarcinoma↗
PubMed1998

[Mobilization of peripheral blood stem cells in advanced ovarian cancer].

High-dose chemotherapy with hematopoietic support has been expected to improve the survival of advanced ovarian cancer patients in recent years. An essential component of such treatment has been the ability to collect and reinfuse a large number of peripheral blood stem cells (PBSCs) following high dose therapy. This study was designed to determine which clinical and hematological factors would be better indicators to collect the proper volume of PBSCs. Thirteen patients received a total of 24 courses of induction chemotherapy and 69 of apheresis. We usually mobilized stem cells using CEP chemotherapy (cisplatin 50-70 mg/m2, epirubicin 50 mg/m2 and cyclophosphamide 1.5 g/m2) with G-CSF and CEE regimen (cyclophosphamide 2.0 g/m2, epirubicin 50 mg/m2, and etoposide 50 mg/m2) as a salvage for mobilization. We obtained an average 5 x 10(6)/kg of CD34+ cells for 3 days as one course. The number of CD34+ cells collected significantly depended on the platelets and reticulocytes on the first day of apheresis, but not a nadir of WBCs. It is concluded that apheresis should be started on recovery of WBCs to 5,000-10,000/microliters, of immature granulocytes to > or = 10% and of reticulocytes to > or = 20%. This study confirmed the feasibility of collecting enough PBSCs to use standard chemotherapy of ovarian cancer patients.

Adult↗
PubMed1998

A new device for thoracic access: the Thoraco Holder.

BACKGROUND: We present a novel invention (Thoraco Holder; Fuji Systems Corporation, Tokyo, Japan) for thoracoscopic surgery. Made of silicone, automatically stops bleeding from the chest wall, increases range of motion for manipulation, and decreases postoperative pain. METHODS: Under general anesthesia using the Univent tube (Fuji Systems Corporation, Tokyo, Japan), two Thoraco Holders were used in each of 300 thoracoscopic procedures for lung cancer, mediastinal tumor, pneumothorax, chest trauma, and emphysema, most using the Two Windows Method). RESULTS: No patient experienced more than 10 mL of bleeding from the chest wall. In addition, analgesics were not needed by any patient for over 1 week. No patient experienced trouble caused by the Thoraco Holder. CONCLUSIONS: The Thoraco Holder is made of silicone. Silicone rubber causes less pain postoperatively. The silicone cuff (balloon) causes less bleeding from the chest wall. This Thoraco Holder is useful access for video assisted thoracoscopic surgery.

Endoscopes↗
PubMed1998

Surgical management of giant schwannoma in the lumbosacral region.

Giant lumbosacral schwannoma is rare and only 11 cases have been reported. We experienced two cases: a 58-year-old woman with recurrent schwannoma from L2 to S3, and a 52-year-old woman with schwannoma from T12 to L5. Total resection was possible in the latter case, which was the patient's first operation. Although she had neurologic deterioration, there was no recurrence during the 4-year follow-up. The recurrent case required a bone graft because of her fragile spine, and she was severely disabled. In the literature, total resection has been confirmed in only two cases of a first operation. Total resection is nonetheless strongly recommended in spite of the risk of leaving a neurologic deficit.

Cauda Equina↗
PubMed1997

Modular structures in the mushroom body of the cockroach.

The mushroom body (MB) is a higher center of the insect brain and is critical to olfactory and other forms of associative memory. Here, we report that repetitive modular subunits, which we refer to as slabs, are present in the internal matrix of the alpha lobe, a major output neuropil of the MB in the cockroach. The methods employed were osmium-ethyl gallate, Bodian-reduced silver, and Golgi staining procedures. A total of 15 dark and 15 pale slabs, each consisting of specific subsets of intrinsic neurons (Kenyon cells), alternate throughout the length of the alpha lobe. One of the major classes of MB output neurons, which are postsynaptic to Kenyon cells, exhibited segmented dendritic arbors that interact with every other slabs, i.e. only either dark or pale slabs. As each output neuron interacts with each specific set of dark or pale slabs, the slab likely functions as a unit for transmitting MB output signals.

Animals↗
PubMed1997

Sequential operation of ceramide synthesis and ICE cascade in CPT-11-initiated apoptotic death signaling.

The chemotherapeutic agent CPT-11 induced apoptotic cell death in mouse fibroblast 4B1 cells. To examine the intracellular apoptotic death signal initiated by CPT-11, ceramide synthesis and the ICE cascade were analyzed. CPT-11-initiated cytolytic activity was prevented by both caspase inhibitors YVAD-CHO and DEVD-CHO, or ceramide synthesis inhibitor fumonisin B1, and accelerated by sphingomyelin, suggesting the direct involvement of ceramide synthesis and the interleukin 1-beta converting enzyme (ICE) cascade. In addition, apoptosis was induced by both native and synthesized ceramide and prevented by YVAD-CHO and DEVD-CHO, suggesting the possible involvement of ceramide in ICE cascade operation. To directly demonstrate whether ceramide synthesis operates the ICE cascade, proteolytic activity of ICE- or CPP32-like proteinase was analyzed. ICE-like proteinase activity was prevented by fumonisin B1 and YVAD-CHO, but not by DEVD-CHO. In contrast, fumonisin B1, YVAD-CHO, and DEVD-CHO all prevented CPP32-like proteinase activity. These results suggest that ceramide synthesis acts as a dominant regulator in CPT-11-initiated death signaling and sequentially operates the ICE cascade.

Animals↗
PubMed1997

Involvement of cytoplasmic serine proteinase and CPP32 subfamily in the molecular machinery of caspase 3 activation during Fas-mediated apoptosis.

On stimulation by the Fas ligand, the death receptor, Fas, initiates a signal leading to apoptotic cell death. Fas plays an important role in physiological cell death and is closely involved in various disease states. Recent investigations have shown that caspase 3 plays a dominant role in the process of Fas-mediated apoptosis. In the present study, we investigated the molecular machinery of caspase 3 activation in Fas-mediated apoptosis. The results showed that Fas-mediated apoptosis was accompanied by caspase 3 activation, and both Fas-mediated apoptosis and caspase 3 activation were prevented by a serine proteinase inhibitor. In addition, the serine proteinase inhibitor also prevented the caspase 3 activation in cytoplasts, and the specific activation of serineproteinase was encountered in only cytoplasmic proteins. These results suggest that cytoplasmic serineproteinase plays an important role in caspase 3 activation. Interestingly, caspase 3 was cleaved at p3 site immediately after Fas Ab stimulation, and the cleavage at p17 site became detectable later. We also found that among tested proteinases only Staphylococcus aureus V8 serineproteinase initiated caspase 3 activation and specifically cleaved at p3 site. These results strongly suggest that a cytoplasmic S. aureus V8-like serine proteinase is closely involved in caspase 3 activation.

Apoptosis↗
PubMed1997

Expression of indian hedgehog, bone morphogenetic protein 6 and gli during skeletal morphogenesis.

A complex signaling pathway involving members of the Hedgehog, Bone morphogenetic protein (Bmp) and Gli families regulates early patterning events in fetal skeletogenesis (Hui and Joyner, 1993. A mouse model of Greig cephalopolysyndactyly syndrome: the extra-toes mutation contains an intragenic deletion of the Gli3 gene. Nat. Genet. 3, 241-246; Bitgood and McMahon, 1995. Hedgehog and Bmp genes are coexpressed at many diverse sites of cell-cell interaction in the mouse embryo. Dev. Biol. 172, 126-138; Lanske et al., 1996. PTH/PTHrP receptor in early development and Indian hedgehog-regulated bone growth. Science 273, 663-666; Vortkamp et al., 1996. Regulation of rate of cartilage differentiation by Indian hedgehog and PTH-related protein. Science 273, 613-622). Hedgehog genes encode secreted proteins that mediate patterning and growth through the induction of secondary signals (reviewed in Hammerschmidt et al., 1997. The world according to hedgehog. Trends Genet. 13, 14-21). Two potential targets of Ihh are bmp6 and gli (Johnson et al., 1995. Patched overexpression alters wing disc size and pattern: transcriptional and post-transcriptional effects on hedgehog targets. Development 121, 4161-4170; Dominguez et al., 1996. Sending and receiving the hedgehog signal: control by the Drosophila Gli protein Cubitus interruptus. Science 272, 1621-1625; Marigo et al., 1996. Sonic hedgehog differentially regulates expression of GLI and GLI3 during limb development. Dev. Biol. 180, 273-283). We investigated the molecular similarities and differences between fetal and postnatal skeletal development by analyzing the coincident and complimentary expression domains of indian hedgehog (ihh), bmp6 and gli in adjacent sections throughout the process of skeletogenesis. In almost all of the skeletal tissues examined, the expression domains of ihh and bmp6 were adjacent to one another and this region was surrounded by gli-expressing cells. These observations are in keeping with the proposed function of gli as a negative regulator of Ihh signaling and the induction of Bmps by Hedgehog proteins (Roberts et al., 1995. Sonic hedgehog is an endodermal signal inducing Bmp-4 and Hox genes during induction and regionalization of the chick hindgut. Development 121, 3163-3174; Kawakami et al., 1996. BMP signaling during bone pattern determination in the developing limb. Development 122, 3557-3566). By puberty, ihh, bmp6 and gli transcripts were no longer detected in the growth plate, despite the fact that physeal chondrocytes continued to hypertrophy and differentiate. Although bmp6 was expressed, ihh transcripts were not found in primordia of intramembranous bones, nor in cells lining the future articular surfaces. Collectively our findings suggest that ihh participates in, but is not required for chondrocyte hypertrophy.

Animals↗
PubMed1997

Craniocaudal motion velocity in the cervical spinal cord in degenerative disease as shown by MR imaging.

PURPOSE: To investigate, by means of MR phase imaging, the effects of compression on the velocity of craniocaudal motion in the spinal cord. MATERIAL AND METHODS: Spin-echo pulse sequences with velocity encoding gradients were used to examine 12 patients with cervical spondylosis and 6 normal volunteers. Oblique-axial phase images at 3 levels (cranial, middle and caudal), were obtained with prospective electrocardiogram gating. The middle level was set at the site where the spinal cord was most severely compressed, and the cranial and caudal sections were set where it was not compressed. Time-velocity curves were generated at these 3 levels and focal velocity change was correlated with motor function in the lower extremities. RESULTS AND CONCLUSION: The cord showed a higher motion velocity at the compression level than at noncompression levels. This paradoxical increase in velocity was observed in 7 out of 8 patients whose lower extremity motor function was impaired. Four patients with normal lower extremity motor function did not demonstrate this increase in velocity. An increase in motion velocity was therefore found to correlate with impaired lower extremity motor function.

Adult↗
PubMed1997

A case of pregnancy in a woman with cloacal dysgenesis and a rudimentary uterine horn.

Cloacal dysgenesis is frequently associated with uterine anomalies. We report a case of pregnancy which resulted in an abortion in a woman with a persistent cloaca. Presumptive diagnosis before operation was ectopic pregnancy of the left tube. Postoperatively, the site of implantation of the conceptus was found to be the cavity of a unicornuate uterus in association with a rudimentary horn, the presence of which misled us to diagnose an ectopic pregnancy.

Abortion, Induced↗
PubMed1997

Comparison of clinical features and survival in patients with hepatitis B and C virus-related hepatocellular carcinoma.

We analyzed the clinical characteristics and survival of 185 patients with hepatitis B virus-related hepatocellular carcinoma (HBV group) and 1033 with hepatitis C virus-related hepatocellular carcinoma (HCV group) by multi center study. The patients in the HBV group (mean age 52.1 yr) were about 10 years younger than those in the HCV group (mean age 62.9 yr). Liver function, as measured by indocyanine green retention at 15 min, was better in the HBV group (17.5%) than in the HCV group (25.4%). A higher proportion of the HBV group (55%) than the HCV group (44%) had clinical stage I, T-factor differed significantly between the groups: 53% of the HBV group were T3-4 compared with 41% of the HCV group. Furthermore, a higher proportion of the HBV group were graded 2-3 for tumor thrombus in the portal vein (20.3%) and had poorly differentiated hepatocellular carcinoma (7%) compared with the HCV group (7.1% and 5% respectively). Univariate analysis identified poor prognostic factors for hepatocellular carcinoma as HBV, age < or = 50 yr, clinical stage II-III, a high AFP level, higher number of tumors, larger tumor size, tumor thrombus in the portal vein 2-3 and in the hepatic vein 2-3. On multivariate analysis, poor prognostic factors were a high AFP level, higher number of tumors, tumor thrombus in the portal vein 2-3 and in the hepatic vein 2-3, but not HBV, age, clinical stage or tumor size. These results suggest that HBV itself is not a stronger prognostic factor than HCV.

Aged↗
PubMed1997

Therapeutic results of resection, transcatheter arterial embolization and percutaneous transhepatic ethanol injection in 3225 patients with hepatocellular carcinoma: a retrospective multicenter study.

The outcome in 3225 patients with hepatocellular carcinoma (HCC) was studied in groups with equivalent prognosis treated with resection, transcatheter arterial embolization (TAE), and percutaneous transhepatic ethanol injection (PEI). Significant factors for better clinical background included a tumor diameter of < or = 30 mm, tumor number < or = 3 and (clinical) Stage I. In patients with Stage I disease having tumors of < or = 30 mm and < or = 3 in number, survival afer resection and PEI did not differ, while survival after TAE was significantly worse. In those patients with Stage II disease, survival after PEI was significantly better than after resection or TAE. In patients with Stage I or II disease having tumors > or = 31 in size and < or = 3 number, survival after resection was significantly better than after TAE. In patients with Stage I disease having tumors of > or = 31 mm and > or = 4 in number, survival after resection was significantly better than after TAE. Our conclusions are as follows. Firstly, resection or PEI is recommended for patients with Stage I disease having < or = 3 tumors all < or = 30 mm in size. Secondly, PEI is recommended for patients with Stage II disease having < or = 3 tumors all < or = 30 mm in size. Thirdly, for patients with Stage I disease having tumors 31 mm or larger in size, whatever the number of tumors, resection should be selected rather than TAE.

Adolescent↗