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Biomedical subjects

Y Shibata

Publications and source records attributed to Y Shibata.

At least 127 records · Page 7Linked to original sources
PubMed2000

MMP-1 is a prognostic marker for hematogenous metastasis of colorectal cancer.

BACKGROUND: Degradation of basement membrane and extracellular matrix by matrix metalloproteinases (MMPs) is believed to be an essential step in the complicated process of hematogenous metastasis. MMP-1 is a member of collagenases, a family of MMPs that degrades collagens type I, II, and III, main components of the interstitial stroma. The purpose of this study was to investigate the expression of MMP-1 in colorectal cancer and its correlation with hematogenous metastasis. Patients and Methods. We examined 133 cases of colorectal cancer (Dukes A: 72; Dukes B: 26; Dukes C: 23; Dukes D: 12). Sections were cut from formalin-fixed, paraffin-embedded samples containing the deepest site of cancer invasion and stained immunohistochemically with a monoclonal antibody to MMP-1. According to the area of the tumor that was stained, patients were divided into high- and low-MMP-1 expression groups. RESULTS: MMP-1 expression was observed in the cytoplasm of cancer cells, some stromal cells, and a few normal epithelial cells of colonic mucosa. High MMP-1 expression was found in 47 (35.3%) cases and low in 86 (64.7%). Hematogenous metastasis was identified in 14 (29.8%) of high-MMP-1 groups and 12 (13.9%) of low-MMP-1 groups. MMP-1 expression significantly correlated with hematogenous metastasis of colorectal cancer, but no correlation was found between MMP-1 expression and the other clinicopathological features investigated. CONCLUSIONS: MMP-1 expression may be a novel marker for hematogenous metastasis of colorectal cancer, and its inhibition may be a strategy for prevention of metastasis.

Adult↗
PubMed2000

Use of microvascular Doppler sonography in aneurysm surgery on the anterior choroidal artery.

Anterior choroidal artery (AChA) syndrome is still one of the most serious complications of the clipping of internal carotid artery aneurysms. No monitoring method can detect ischemia in the area of the AChA during surgery. This artery may be obstructed when a clip is applied to the neck of the aneurysm, and patency is sometimes difficult to confirm by microscopy because of the artery's small size and site of origin (usually behind the internal carotid artery as viewed surgically). However, microvascular Doppler sonography (MVDS) can detect flow instantaneously even in such a small vessel. In our series, AChA syndrome occurred in three of 19 patients treated for AChA aneurysm before the introduction of MVDS, but only one of 19 patients treated with the aid of this device. In that patient, one of the two AChA branches was intentionally sacrificed by applying a clip to the prematurely ruptured aneurysm. MVDS detected hypoperfusion of the AChA after clipping in five other patients, and so the clip was readjusted to preserve AChA flow. Use of MVDS is very effective to prevent inadvertent injury to the AChA during aneurysm surgery on this artery.

Adult↗
PubMed2000

Ruptured aneurysm at the origin of the median artery of the corpus callosum associated with accessory middle cerebral artery--case report.

A 62-year-old male presented with ruptured anterior communicating artery (ACoA) aneurysm manifesting as severe headache associated with the rare combination of median artery of the corpus callosum (MACC) and accessory middle cerebral artery (MCA). Computed tomography demonstrated diffuse subarachnoid hemorrhage. Left carotid angiography demonstrated an anomalous vessel originating from the ACoA complex and passing forward in the interhemispheric fissure between the two companion A2 segments. This vessel was identified as the MACC. Another anomalous vessel originated from the left A1-A2 segment and passed into the sylvian fissure. This vessel was identified as the accessory MCA. Left frontotemporal craniotomy was performed to clip the neck of the aneurysm. After identifying both A1 and A2 segments, accessory MCA, and the MACC, the aneurysm neck was occluded successfully. The ACoA complex is one of the most frequent sites of vascular anomalies. Preoperative and intraoperative care is required to identify the presence of anomalies of the ACoA complex prior to clip placement, to avoid accidental damage or clipping, which may result in severe neurological deficits.

Anterior Cerebral Artery↗
PubMed2000

Differences in TNF-alpha producing activity from murine peritoneal macrophages induced by lipopolysaccharides of Prevotella heparinolytica and Porphyromonas gingivalis.

We compared the effects of LPSs from P. gingivalis and P. heparinolytica on the induction of tumor necrosis factor-alpha (TNF-alpha) production by murine peritoneal macrophages. The lipopolysaccharide (LPS) preparation from P. gingivalis showed a typical ladder pattern in SDS-PAGE, whereas that from P. heparinolytica formed several stained bands without a ladder pattern. When the macrophages from C3H/HeJ mice were incubated with P. gingivalis LPS, the level of TNF-alpha released in the culture supernatants was significantly higher than that with P. heparinolytica. All tested reagents except genistein strongly inhibited the production of TNF-alpha by the macrophages after induction by either LPS. These results suggested the following possibilities, i) the induction level of TNF-alpha by P. heparinolytica is similar to that of Salmonella minnesota, ii) tyrosine phosphorylation is not the only pathway for the TNF-alpha production induced by these LPSs, iii) different regulatory mechanisms are involved in TNF-alpha production in P. gingivalis LPS stimulated and P. heparinolytica LPS stimulated cells.

Animals↗
PubMed2000

[Autologous blood transfusion in surgery of urologic malignant tumor].

BACKGROUND: Autologous blood transfusion has been widely endorsed, because of the adverse effects attributed to homologous blood transfusion. So we employed autologous blood transfusion to avoid homologous blood transfusion in operation of urological malignant patients. We reviewed our experience with autologous blood transfusion in 48 patients. METHODS: A total of 48 patients underwent operation with 400 to 1,200 ml preoperative autologous blood donation, in 41 patients with administration of erythropoietin and 7 patients without erythropoietin. The details of operations are radical nephrectomy in 18 cases (2 cases were bilateral), radical nephro-ureterectomy in 2 cases, retroperitoneal lymph node dissection (RPLND) in 2 cases, radical prostatectomy in 12 cases and radical cystectomy in 14 cases. RESULTS: The volume of surgical blood loss were 381 +/- 522 ml in nephrectomy (1,158 +/- 202 ml in bilateral case), 517 +/- 5 ml in radical nephro-ureterectomy 636 +/- 574 ml in RPLND, 665 +/- 291 ml in radical prostatectomy and 1,123 +/- 417 ml in radical cystectomy. Only three cases needed homologous blood transfusion. CONCLUSION: We can avoid homologous blood transfusion in 94% of patients. Autologous blood transfusion is recommended as safe and convenient.

Adult↗
PubMed2000

Time-domain observation of conformational fluctuation of protein by time-resolved hole-burning spectroscopy.

Recent progress in structural biology has disclosed that protein function relies largely on its conformational flexibility. A protein molecule assumes a large number of slightly different conformations called "conformational substates (CSs)". At room temperature in an aqueous solution, transitions among many CSs take place and induce large conformational fluctuation, which is considered to be indispensable for its function. Time-resolved transient hole-burning (TRTHB) spectroscopy is becoming one of the most powerful tools to do direct time-domain measurement of the conformational fluctuation dynamics of a protein. In this technique, transition process among CSs is detected through the temporal variation of the "hole-burning" spectrum formed in the absorption spectrum by laser irradiation. Conformational fluctuation dynamics of protein is observed as a function of time in a very wide temporal range from ns up to ms. This article reviews some recent applications of TRTHB method to the observation of conformational fluctuation of myoglobin and cytochrome c.

Cytochrome c Group↗
PubMed2000

[Metabolic acidosis and ketone body in severely head-injured patients].

Increase of ketone body concentration in plasma is induced by various factors such as onset of diabetes. Secretion of excessive stress hormone including catecholamine is responsible for stimulation of lipolysis which increases plasma ketone body concentration. Catecholamine levels reflect the severity of the neurologic insult, so this is a basis for the use of catecholamine measurements as a physiological marker of patient outcome. Twenty-seven patients with severe head injury and twenty-five healthy volunteers were enrolled in this study, but patients with diabetes or liver dysfunction were excluded. The patients with severe head injury consisted of 19 with focal injury and 8 with diffuse injury. The outcome was as follows; 14 patients died and 13 patients survived. We collected arterial blood samples as promptly as possible after onset of severe head injury and measured the following: 1, base excess; 2, beta-hydroxybutyrate; 3, acetoacetate; 4, lactate; 5, epinephrine; 6, norepinephrine. The ketone body (beta-hydroxybutyrate + acetoacetate) concentration in plasma was significantly elevated in patients with severe head injury. The increment of beta-hydroxybutyrate levels was greater than that of acetoacetate levels, resulting decreased arterial ketone body ratio (AKBR; acetoacetate/beta-hydroxybutyrate). We demonstrated that plasma ketone body concentrations were elevated and the AKBR decreased in severe head-injured patients. Elevation of catecholamine has been reported as a stress reaction in severe head injury. Catecholamine is most potent in stimulating lipolysis, and ketogenesis. Therefore, the ketonemia observed in severe head injury is most likely to be induced by elevation of catecholamine levels. The degree of ketonemia may be an index of the severity of severe head injury.

3-Hydroxybutyric Acid↗
PubMed2000

Complementation of an hMSH2 defect in human colorectal carcinoma cells by human chromosome 2 transfer.

The human colorectal tumor cell line LoVo has a homozygous deletion in the hMSH2 gene from exon 3 to exon 8, is deficient in mismatch repair (MMR) activity, and exhibits microsatellite instability. To determine whether the introduction of a wild type hMSH2 into LoVo restores MMR activity and stabilizes microsatellite loci, we transferred a chromosome 2 fragment containing hMSH2 into a homologous recombination-proficient chicken DT40/human hybrid (DT40 2C) and a human chromosome 2 in a mouse A9 hybrid to LoVo. Transfers of these chromosomes into LoVo resulted in LoVo both with and without a wild-type hMSH2. Complete correlation was found between the presence of the wild-type hMSH2 and hMSH2 expression, an increased stability in microsatellite loci, and competency in MMR. The hMSH2-positive LoVo hybrids also showed an increased sensitivity to N-methyl-N'-nitro-N-nitrosoguanidine. This enhanced toxicity is associated with G(2) cell-cycle arrest followed by premature mitosis and cell death. These results suggest that hMSH2 may be responsible for complementing mutator and drug-resistant phenotypes in chromosome 2-transferred LoVo cells. To test whether the hMSH2 in DT40 2C cells can be modified by homologous recombination, we transfected DT40 2C with a targeting vector containing an hMSH2 exon 4 disrupted by the zeocin-resistant gene. The results showed that the hMSH2 locus in DT40 2C was efficiently targeted by an exogeneously transfected homologous sequence, suggesting that transfer of a modified hMSH2 from DT40 2C to LoVo via chromosome transfer could be used to determine the function of hMSH2.

Animals↗
PubMed2000

Human urine certified reference material for arsenic speciation.

BACKGROUND: Chemical speciation analysis is essential for the biological monitoring of inorganic arsenic exposure using urine as indicator medium. There is increasing demand for a certified reference material (CRM) of urine matrix for arsenic speciation. METHODS: Urine (10 L) was collected from non-occupationally exposed Japanese males. We prepared 954 bottles of urine, each containing approximately 10 mL, after filtering and blending the urine stock. The urine in each bottle was freeze-dried. Between-bottle homogeneity was confirmed by measuring the concentrations of selected minor and trace elements in the material and subsequent statistical analysis. Certification was based on a collaborative analysis involving 15 laboratories. RESULTS: Certified values were determined for arsenobetaine (0.069+/-0.012 mg As/L), dimethylarsinic acid (0.036+/-0.009 mg As/L), and total arsenic (0.134+/-0.011 mg/L) as well as for total selenium (0.059+/-0.005 mg/L) and zinc (0.62+/-0.05 mg/L), based on the analytical values from the collaborating laboratories. Reference values are given for copper (0.010 mg/L) and lead (0.0011 mg/L), based on definitive analysis at the National Institute for Environmental Studies (NIES). CONCLUSIONS: The present CRM, NIES CRM No. 18 Human Urine, is the first human urine CRM for arsenic speciation and will be of value for analytical quality assurance of the biological monitoring of arsenic exposure.

Arsenicals↗
PubMed2000

A convenient in vitro screening method for predicting in vivo drug metabolic clearance using isolated hepatocytes suspended in serum.

A novel and convenient in vitro method for predicting in vivo metabolic clearance in the liver (CL(H)) was developed. The CL(H) of a drug is usually predicted by using both the unbound fraction in serum and the intrinsic hepatic clearance of the unbound fraction, but this procedure is labor-intensive. We simplified the method by directly measuring intrinsic hepatic clearance using isolated rat hepatocytes suspended in rat serum and called this "the serum incubation method". Sixteen commercially available compounds reported to be mainly excreted by liver metabolism were evaluated using our method. The remaining ratio of the unchanged drug after incubation was measured to calculate the rate of metabolism, and then CL(H) was predicted based on the dispersion model. The predicted CL(H) values of the drugs estimated by the serum incubation method were in good agreement with their in vivo plasma clearance values. In addition, the intrinsic hepatic clearance values obtained by the serum incubation method were comparable with those obtained by conventional methods. Furthermore, oral bioavailability values were equal to or lower than hepatic availability values predicted from the serum incubation method. These results indicate that compounds showing poor oral bioavailability can be excluded before in vivo pharmacokinetic study by using this method. In conclusion, the serum incubation method is a convenient and useful tool at the early stage of drug discovery.

Algorithms↗
PubMed2000

Intramedullary clear cell ependymoma in the cervical spinal cord: case report.

OBJECTIVE AND IMPORTANCE: Clear cell ependymoma of the spinal cord has not been reported in the literature, although ependymoma in the cerebral and cerebellar hemispheres has been described. We present the first case report of this rare histological type of ependymoma arising in the cervical spinal cord and emphasize the importance of recognizing this histological entity. CLINICAL PRESENTATION: A 42-year-old woman presented with numbness in both upper limbs and spastic gait. Magnetic resonance imaging revealed an intramedullary tumor at the C6-T1 level with syringomyelia. INTERVENTION: The tumor was totally removed. Histological analysis revealed that the tumor was composed of round cells with perinuclear halos similar to those observed in oligodendroglioma. However, we diagnosed clear cell ependymoma because these tumor cells exhibited epithelial features and ependymal rosettes under light microscopic examination. CONCLUSION: Histological diagnosis was crucial to our determining whether to perform postoperative adjuvant therapy in this patient. Neurosurgeons should be aware of the possibility of this histological entity among intramedullary spinal cord tumors.

Adult↗
PubMed2000

Risk of colorectal cancer in patients with hematologic disease.

BACKGROUND AND AIMS: A relatively large number of patients with multiple myeloma have been reported to develop a secondary malignancy such as cancer of the breast, biliary system or bowel. METHODS: A retrospective study was perfomed in 734 patients with hematologic disease diagnosed at Nippon Medical School Hospital between May 1984 and September 1994 to determine the incidence of colorectal cancer in these patients based on a history review, colonoscopic findings, and surgical or autopsy data. RESULTS: Of the 734 patients, 14 (1.9%) had colorectal cancer; two of 11 patients (18.2%) had pure red cell aplasia; two of 25 patients (8%) had multiple myeloma; and three of 46 patients (6.5%) had aplastic anemia. Patients with pure red cell aplasia, multiple myeloma or aplastic anemia had colorectal cancer at a significantly higher rate compared to those with leukemia (P< 0.005, P< 0.02, P< 0.01, respectively). CONCLUSIONS: It is possible that a relatively large number of patients with pure red cell aplasia, multiple myeloma or aplastic anemia will develop a colorectal cancer.

Aged↗
PubMed2000

Acute epididymo-orchitis with abscess formation due to Pseudomonas aeruginosa: report of 3 cases.

We report 3 patients with acute epididymo-orchitis with abscess formation due to Pseudomonas aeruginosa, which is relatively unusual and difficult to treat. All patients presented with swollen testicles, pain and high fever. First, they were treated empirically with several antibiotics. After several weeks of antibiotics therapy, the swelling of scrotum still persisted. In one patient, dark yellow pus drained from a fistula of the scrotum. Finally, an orchiectomy was performed on all patients. During the operation, an abscess was found in each testis. Each culture of the pus yielded P. aeruginosa, which is susceptible to many antibiotics.

Abscess↗
PubMed2000

[Concentration of isepamicin sulfate in bone marrow blood].

Fifteen patients who were performed a rotator cuff repair were subjected for the determination of a concentration of isepamicin sulfate (ISP), which was infused intravenously, in venous blood and bone marrow blood. The concentrations were measured at 0, 30, 60 minutes after the injection. There was no statistically significance between ISP concentrations in venous and bone marrow blood. This study revealed that the transference of ISP to the bone marrow was excellent.

Adult↗
PubMed2000

[Correlation between prior coronary revascularization and perioperative cardiac events in patients for noncardiac surgery].

We evaluated the influence of interval between prior coronary revascularization and subsequent noncardiac surgery on perioperative cardiac events. We retrospectively identified 162 consecutive patients with previous revascularization procedures who had undergone noncardiac surgery. Postoperative cardiac complications occurred in 10 (6.2%) patients, cardiac death in 1 patient, and significant arrhythmia in 3 patients. These patients had higher rates of unstable angina, myocardial infarction within 3 months, cerebrovascular disease, peripheral vascular disease, renal dysfunction (Cr > or = 1.9 mg.dl-1) and higher preoperative risk scores as described by the Cleveland Clinic (P < 0.05). Also, the incidence of cardiac complications increased when noncardiac surgery was performed within 1 week of previous percutaneous transluminal coronary angioplasty (PTCA) and in more than 5 years after coronary artery bypass grafting or PTCA (P < 0.05). Although PTCA is widely accepted, especially in Japan, early lesion progression was observed during the first several days and atherosclerotic progression was apparent in more than 5 years after the procedure. Therefore, the time between coronary revascularization and noncardiac surgery, as well as atherosclerotic risk factors, is important in evaluating patients with history of previous revascularization procedures.

Aged↗
PubMed1999

Antithrombotic activity of avian crown dermatan sulfate.

The antithrombotic activity of dermatan sulfate from avian crown with the mean molecular weight of 38000 was compared to those from bovine intestine with the mean molecular weight of 16000 in vivo and in vitro. In an in vitro test, bovine intestine dermatan sulfate exhibited stronger effects on stimulation of heparin cofactor II and activation of Glu-plasminogen by tissue plasminogen activator. In vivo, avian crown dermatan sulfate more effectively prevented the development of thrombus in a rat deep vein thrombosis model. The measurement of plasma levels of these two kinds of dermatan sulfate revealed that avian crown dermatan sulfate circulated in higher concentration and longer duration than bovine intestine dermatan sulfate after intravenous administration to rats.

Animals↗
PubMed1999

Induction of tumor necrosis factor alpha and nitric oxide in rabbits inoculated with a cyst extract of Sarcocystis cruzi.

Rabbits develop a toxic reaction similar to endotoxemia following inoculation with a Sarcocystis cruzi cyst extract. To analyze the pathophysiology of the reaction, serum tumor necrosis factor alpha (TNFalpha), nitric oxide (NO) and lipid-lipoprotein profiles were investigated in rabbits given the cyst extract and lipopolysaccharide (LPS) by subcutaneous inoculation. In animals given the cyst extract, overproduction of TNFalpha was detected, together with an increase in NO. The animals developed derangement of lipid metabolism, which was considered to have resulted from TNFalpha induction, consisting of elevated triglyceride and very low density lipoprotein levels and decreased high density lipoprotein (HDL) levels. Serum interleukin-6-like activity also increased transiently in the animals. Capability of the cyst extract to induce TNFalpha, NO and the lipid profile derangement were completely lost by boiling. In animals given LPS, TNFalpha was induced and HDL decreased moderately, without inactivation of those activities of LPS by boiling. These results indicated that S. cruzi cyst extract is a potent, but thermolabile inducer of TNFalpha and NO for rabbits. It is likely that TNFalpha and NO play important roles as mediators in the reaction associated with toxicity of the cyst extract in rabbits.

Animals↗