Biomedical subjects

K Sano

Publications and source records attributed to K Sano.

At least 253 records · Page 14Linked to original sources

PubMed1997

Effects of hypoxemia on early postoperative course of liver transplantation in pediatric patients with intrapulmonary shunting.

Nine pediatric patients (mean age, 10 years) with biliary atresia, who had hypoxemia related to intrapulmonary shunting, underwent living related liver transplantation. The effects of hypoxemia during the early postoperative period after liver transplantation on cardiopulmonary and renal function, as well as on transplanted liver, were analyzed. Based on the degree of shunt ratio calculated by technetium-99m macroaggregated albumin scintigraphy, the nine patients were included in the moderate group (shunt ratio under 40%, n=4) or the severe group (shunt ratio over 40%, n=5). Partial pressure of arterial oxygen was maintained at normal range in the moderate group, while that in the severe group persistently had very low values (<50 mmHg), in spite of a high degree of oxygen supply. However, all patients in the severe group maintained stable cardiopulmonary vital signs, including systemic blood pressure, heart rate, respiratory rate, and cardiac index. They also demonstrated stable renal function. None of the patients died of cardiopulmonary or renal insufficiency after transplantation, but three patients died of portal vein thrombosis, sepsis, and intracranial hemorrhage (one each). The minimal adverse effect of hypoxemia on the transplanted liver was confirmed by a rapid increase of arterial ketone body ratio, low peak values (under 200 IU/L) of aspartate aminotransferase, and a steady decrease of serum total bilirubin. Four patients encountered surgical complications, including two bile leaks from the cut liver surface, two leaks from bilioenteric anastomosis, and one intestinal perforation. Six patients suffered from bacterial infections, including four wound infections, three right subphrenic abscesses, one cholangitis, and two systemic sepses. All patients in the moderate group recovered from hypoxemia, but four of five patients in the severe group have not recovered during the follow-up period between 4 and 9 months. It was concluded that the adverse effects of hypoxemia on cardiopulmonary and renal function and transplanted liver were minimal, so that patients with severe hypoxemia could tolerate the stress of liver transplantation without special management. However, the high incidence of surgical complication and infection suggested the adverse effects of hypoxemia on wound healing and resistance to bacteria infection.

Adolescent↗

PubMed1997

Crystallization and preliminary X-ray crystallographic study of the ribosomal protein S7 from Bacillus stearothermophilus.

Overproduction and crystallization of Bacillus stearothermophilus ribosomal protein S7 (BstS7), a primary 16S rRNA binding protein and also a translational repressor protein, have been performed to analyze its three-dimensional structure by X-ray crystallography. Ribosomal protein BstS7 was expressed in the cytoplasmic fraction of the E. coli cells and purified to homogeneity. This recombinant BstS7 was used to produce crystals with P2(1) symmetry that diffracted to 2.5 A resolution which are suitable for high-resolution X-ray crystallographic analysis.

Crystallization↗

PubMed1997

Impact of intraoperative ultrasonography on surgery for cystic lesions of the pancreas.

The impact of intraoperative ultrasonography (IUS) on surgery for cystic lesions of the pancreas (CLPs) has not been fully clarified. Twenty patients with CLPs, including 5 pseudocysts and 15 true cysts, were scanned intraoperatively to evaluate the utility and practicality of IUS for CLPs. In four of the five patients with pseudocysts and two with retention cysts, the operative procedures were performed under IUS guidance. In one with a pseudocyst, IUS showed that the cyst did not involve the pancreas, and subsequently cystectomy without pancreatic resection was necessary. In one of the two patients with mucin-producing cystadenocarcinomas, IUS demonstrated a skip lesion in the duct of the pancreatic tail, which contributed to changing the operative procedure from pancreatoduodenectomy to total pancreatectomy; in the other, IUS showed that the lesion was localized in the body of the pancreas, and subsequently segmental pancreatectomy was carried out instead of scheduled pancreatoduodenectomy or distal pancreatectomy. Thus in these three patients the operative procedures were changed in light of the IUS findings. In the remaining 11, although IUS visualized CLPs clearly, it added no new information relevant to the operations. We conclude that IUS contributes to performing surgery for certain types of CLP, such as pseudocysts with severe inflammation, retention cysts with nonpalpable or invisible small cysts, mucin-producing cystadenocarcinomas, and possibly other lesions.

Cystadenocarcinoma, Mucinous↗

PubMed1997

Effects of carbachol and catecholamines on ultrastructure and intracellular calcium-ion dynamics of acinar and myoepithelial cells of lacrimal glands.

The current study was carried out to investigate autonomic nervous control of secretory functions in the lacrimal gland. To distinguish the difference between the responses to cholinergic and adrenergic agonists in acinar and myoepithelial cells in the lacrimal gland of guinea pigs, the morphological and functional responses to the agonists were examined by electron microscopy and by digital-imaging analysis of the intracellular concentration of Ca2+ ([Ca2+]i) using fluorescent Ca2+-indicators (Fura-2/AM and Indo-1/AM). In the resting state, exocytosis was rare, and the [Ca2+]i in acinar and myoepithelial cells was low (less than 300 nM). Stimulation with carbachol (CCh) induced a rapid rise in [Ca2+]i reaching a peak level followed by gradual decay and an appearance of many exocytotic figures. Approximately 4-8 s after an initial increase of [Ca2+]i, myoepithelial cells commenced contraction. Noradrenaline or adrenaline induced an increase in [Ca2+]i and exocytosis in acinar cells, but caused no [Ca2+]i increase in myoepithelial cells. In a Ca2+-deficient environment, the responses to CCh in myoepithelial cells and those to noradrenaline in acinar cells were inhibited, whereas the responses to CCh in acinar cells remained unchanged. Isoproterenol caused no effect on [Ca2+]i dynamics, although it occasionally induced exocytosis. Different cellular signaling pathways may be involved in the responses in acinar and in myoepithelial cells to different agonists. Lacrimation mechanisms are redundant.

Animals↗

PubMed1997

The effect of donor and recipient age on engraftment of tissue-engineered liver.

A novel treatment for end-stage liver disease using heterotopic hepatocyte transplantation on biodegradable polymers has been investigated. Survival and repopulation of adequate cell mass to replace hepatic function has been the principal difficulty of this method. Hence the authors have begun to investigate the role of donor and recipient age on the efficiency of hepatocyte transplantation. Lewis rats were used as donors and recipients. Hepatocytes were isolated with a collagenase digestion, both for the adult and fetal livers (17 days estimated gestational age). After digestion, the hepatocytes were seeded onto 95% porous poly-(L)-lactic acid matrices. The polymer-cell constructs with adult or fetal cells were then implanted between mesenteric leaves of three different recipient groups: adults (approximately 200 g), 2-week, and 4-week neonates (two to five animals per group, depending on litter size). The specimens were harvested at 4 weeks, stained with Hematoxylin and Eosin (H&E), and the cell area of each specimen (24 sections per group) was quantitated using morphometric analysis. Results were statistically analyzed using an unpaired, two-tailed Student's t test. At 4 weeks, all specimens showed survival of groups of hepatocytes, especially along the periphery of the polymers and near blood vessels. The hepatocyte cell area for the six groups was calculated in square micrometers: the adult cells transplanted into adult recipients, 0.16 x 10(5) microns2; fetal cells into adults, 0.47 x 10(5) microns2; adult into 4-week neonates, 1.17 x 10(5) microns2; fetal into 4-week neonates, 4.54 x 10(5) microns2; adult into 2-week neonates, 2.98 x 10(5) microns2, and fetal into 2-week neonates, 5.81 x 10(5) microns2. In all three recipient groups, the area of fetal hepatocytes was approximately two to three times the area of the adult hepatocytes (P < .05 for 2-week and 4-week neonatal recipients, P = .06 for adult recipients). Also, as the recipient age decreased, there was an increase in the hepatocyte cell area (P < .05 for fetal or adult groups). The authors conclude that fetal hepatocytes heterotopically transplanted have a significant survival advantage over adult hepatocytes, independent of recipient age. The authors further conclude that the neonatal environment is more favorable than the adult environment for implantation of hepatocytes.

Age Factors↗

PubMed1997

Experimental study of epithelialization of the muscle-only flap in the oral cavity.

PURPOSE: The purpose of this study was to observe the epithelialization process of the muscle-only flap used for reconstruction of the oral mucosal defects. MATERIALS AND METHODS: Forty-three male adult Japanese rabbits were used. A superiorly based cleidomastoid muscle flap was designed after vascular assessment. The flap was transferred into the oral cavity to cover a mucoperiosteal defect made in the mandibular alveolus. Epithelialization of the flap was histologically evaluated at designated intervals. RESULTS: The flaps survived without ischemic necrosis. By 8 days postoperation, the flap was infiltrated by acute inflammatory cells and being replaced by granulation tissue originating from the adjacent tissues. The oral epithelial cells advanced onto this granulating muscle flap, with eventual coverage by 21 days. The granulation tissue matured to fibrous tissue with significant contraction by 2 months. At 6 months postoperation, abnormally hyperkeratinized epithelium was seen on the flap. This differed from the surrounding parakeratinized oral epithelium. CONCLUSIONS: The muscle-only flap in the oral cavity epithelializes after the granulation process.

Actins↗

PubMed1997

Efficacy and risk of ventricular drainage in cases of grade V subarachnoid hemorrhage.

We retrospectively evaluated efficacy and risk of external ventricular drainage which was performed in early management of high grade subarachnoid hemorrhage. Acute ventricular drainage was performed on 36.6% of 93 patients with grade V subarachnoid hemorrhage. The percentage of patients whose GCS improved following ventricular drainage were 14.3% from GCS 3, 61.5% from GCS 4, 42.9% from GCS 5 and 42.9% from GCS 6. The occurrence rate of rebleeding was approximately three-fold higher in patients who underwent ventricular drainage than in patients who did not. Aneurysmal surgery performed after ventricular drainage, compared with acute aneurysmal surgery, resulted in the smaller percentage of patients who became persistently vegetative and in the larger percentage of patients who became severely disabled, while it did not change the percentage of patients who resulted in favorable outcome and death. These results of retrospective study suggested that ventricular drainage performed on grade V subarachnoid hemorrhage increased the risk of rebleeding and did not increase the percentage of patients who resulted in favorable outcome although it reduced the percentage of patients who resulted in persistent vegetative state.

Adult↗

PubMed1997

p21 (WAF1/Cip1/Sdi1/Pic1) mRNA is expressed in neuroblastoma cell lines but not in Ewing's sarcoma and primitive neuroectodermal tumor cell lines.

The p21 protein inhibits the activity of cyclin-Cdk complexes and suppresses cell cycle progression. Wild type p53 can induce p21, but mutated p53 cannot. Previous studies have demonstrated that mutation of p53 is absent in neuroblastoma (NB). These reports prompted us to examine whether p53 induced p21 in NB. We examined the expression of p21 and p53 mRNA in eight NB, two Ewing's sarcoma (ES) and two primitive neuroectodermal tumor (PNET) cell lines by Northern blot analysis, and sequenced p53 cDNA of these cells. Although p53 mRNA was detected in all analyzed cell lines by Northern blot analysis, p21 mRNA was detected in six NB but not in two NB, two ES and two PNET cell lines. We detected the point mutation of p53 at codon 273 (CGT to TGT) in one NB and two ES cell lines. The non-transforming substitution at codon 72 (CCC to CGC) was detected in all analyzed cell lines. One PNET cell line had a large deletion of p53 cDNA. These results showed that p21 mRNA was usually expressed in NB but not in ES and PNET. This may suggest that the down stream of the p53 signal transduction pathway in NB is different from that of the closely related tumors of ES and PNET.

Blotting, Northern↗

PubMed1997

Small cell carcinoma of the prostate: a case report.

A case of small cell carcinoma of the prostate without a primary lesion in the lung was reported. The cancer was diagnosed after the patient complained of lumbago caused by bone metastasis. The tumor was 5.9 x 5.0 x 4.6 cm. The patient was treated with 4 courses of chemotherapy using cisplatin and etoposide. The tumor diminished to 4.0 x 4.0 x 3.5 cm after completion of the 4 courses of treatment. Prostatic antigen levels were less than 1.0 ng/mL during the therapy. Neuron-specific enolase levels were 35.9 ng/mL at the beginning of therapy, and decreased to 7.4 ng/mL after completion of 4 courses of treatment. The patient died 3 months after the completion of treatment. This regimen had some value for inhibiting the growth of small cell carcinoma.

Biopsy, Needle↗

PubMed1997

Mutational analysis of human immunodeficiency virus type 1 (HIV-1) accessory genes: requirement of a site in the nef gene for HIV-1 replication in activated CD4+ T cells in vitro and in vivo.

Human immunodeficiency virus type 1 (HIV-1) accessory genes including nef, vif, and vpr are important factors that determine the replication and pathogenesis of HIV-1. The state of activation is also important for the replication of HIV-1. We evaluated the properties of nef-, vif-, and vpr-minus macrophage-tropic HIV-1(JR) CSF in primary CD4+ Th1- or Th2-like cell cultures which had been activated through CD3 molecules in the presence of interleukin-2 (IL-2) and IL-12 (Th1-like culture) or IL-4 (Th2-like culture), respectively. In activated Th1- or Th2-like cultures, replication of nef-minus HIV-1(JR-CSF) was markedly lower than that of wild-type HIV-1. Subsequent analysis by site-directed mutagenesis showed that (i) the presence of an acidic amino acid-rich domain (amino acid residues 72 to 75) in the Nef protein was critical for the enhancement of viral DNA synthesis, resulting in increased virus growth rate, and (ii) prolines that form part of Src homology 3 binding domain were not essential for viral replication. We also confirmed the importance of sites by using an HIV-1-infected animal model, the hu-PBL-SCID mouse system, representing HIV-1 replication and pathogenesis in activated CD4+ T cells in vivo. These results indicate that Nef accelerates viral replication in activated CD4+ T cells.

Amino Acid Sequence↗

PubMed1997

Analysis of biliary drainage in the caudate lobe of the liver: comparison of three-dimensional CT cholangiography and rotating cine cholangiography.

PURPOSE: To evaluate the bile duct anatomy of the caudate lobe without disease involvement with use of three-dimensional (3D) cholangiography and to compare the usefulness of this technique with that of rotating cine cholangiography. MATERIALS AND METHODS: In 12 patients with obstructive jaundice but without lesions at the hepatic hilum who underwent percutaneous transhepatic biliary drainage, serial examination was performed with cine cholangiography and helical computed tomography (CT). From helical CT scans, 3D cholangiograms were reconstructed. Cine and 3D cholangiograms were evaluated and compared simultaneously. RESULTS: In the 12 patients, 40 branches of the caudate lobe were detected with 3D cholangiography (mean, 3.3 branches per patient), while 31 were detected with cine cholangiography (mean, 2.6 branches per patient). The difference in detection rate was significant (P < .01). Nine (23%) of 40 branches were detected with 3D cholangiography alone, and all 31 branches detected with cine cholangiography were also detected with 3D cholangiography. CONCLUSION: 3D cholangiography was superior to cine cholangiography in assessment of bile duct anatomy of the caudate lobe of the liver because 3D cholangiography eliminated the overlap of different branches of the bile duct.

Aged↗

PubMed1997

CD44 expression on blood eosinophils is a novel marker of bronchial asthma.

Bronchial asthma is characterized by infiltration of the respiratory tracts by eosinophils. A wide variety of adhesion molecules expressed by eosinophils have been proposed to be involved in binding of eosinophils to the vascular endothelium and subsequent transmigration from the circulation to the airways, while little is known about CD44 expression on eosinophils. We introduced a novel staining combination with which surface markers on eosinophils could be analyzed without purification prior to staining, and examined the expression of CD44 on eosinophils. Staining of eosinophils with anti-CD 16 and anti-VLA-4 mAbs enabled us to delineate eosinophils as VLA-4high CD 16- cells from any other leukocyte populations in the whole blood. CD44 was found to be constitutively expressed on resting eosinophils, and expression increased upon cytokine-mediated activation. In all bronchial asthma patients examined, CD44high eosinophils were enriched in sputum relative to peripheral blood, indicating that eosinophils in sputum were more activated than those in blood. By comparing the extent of CD44 expression on blood eosinophils from poorly controlled and well-controlled asthma patients, we unexpectedly found that the density of CD44 expression is higher on blood eosinophils from the well-controlled group. Thus, the extent of CD44 expression on blood eosinophils is a novel marker indicative of the mangement of bronchial asthma. Deterioration of the asthma management with a concomitant decrease in CD44 expression on peripheral eosinophils implies that CD44 may play an important role in facilitating the transmigration of activated, CD44high eosinophils from the circulation to the respiratory tracts.

Asthma↗

PubMed1997

Effects of balloon pulmonary valvuloplasty on atrial shunting--a patient with pulmonary valve stenosis and a large secundum atrial septal defect.

Percutaneous balloon valvuloplasty has been established as an effective treatment for pulmonary valve stenosis (PS) in children and adults. However, there are few reports of the use of this technique in patients with other cardiac anomalies. We report the performance of balloon pulmonary valvuloplasty in a 72-year-old woman with a large atrial septal defect (ASD). This patient had a PS with a right ventricular pressure of 108/18 mmHg and a pulmonary arterial pressure of 42/21 mmHg, corresponding to a 66 mmHg pressure gradient. The ASD measured 32 x 27 mm. Balloon pulmonary valvuloplasty reduced the pressure gradient to 5 mmHg immediately after the procedure and to 2 mmHg 40 days after the procedure. The left-to-right shunt ratio was reduced from 17% before to 12% immediately after and to 36% 40 days after the procedure. In contrast, the right-to-left shunt ratio showed a transient increase from 16% before to 28% immediately after the procedure before decreasing to 11% 40 days after the procedure. The arterial blood oxygen tension was 53 Torr before, 46 Torr immediately after and 55 Torr 40 days after the procedure. The grade of heart failure decreased from New York Heart Association class IV before to class II in the chronic stage. These findings indicated that balloon pulmonary valvuloplasty in a patient with ASD transiently increased the right-to-left shunting associated with a decrease in oxygen tension, but that the change in the chronic stage was slight. In our patient with ASD valvuloplasty was useful in relieving the symptoms associated with elevated right ventricular pressure but could not reduce the hypoxemia caused by right-to-left shunting. In conclusion, valvuloplasty in patients with ASD should be considered as a preoperative treatment with the aim of reducing the risk of surgery and to treat symptoms in patients who refuse to undergo surgery.

Aged↗

PubMed1997

Effects of an Escherichia coli ilvA mutant gene encoding feedback-resistant threonine deaminase on L-isoleucine production by Brevibacterium flavum.

A mutated ilvA gene of Escherichia coli encoding a threonine deaminase that is resistant to feedback inhibition by L-isoleucine was obtained. It was functional in Brevibacterium flavum, and a wild strain of B. flavum into which it was introduced became able to convert exogeneous L-homoserine and L-threonine to L-isoleucine. When it was introduced into a L-threonine-producing B. flavum strain, the transformant accumulated 20 g/liter L-isoleucine from 100 g/liter glucose.

Brevibacterium↗

PubMed1997

Ethanol sclerosis: one of the best treatments for thymic cyst in very elderly patients?

An 83-year-old female patient with a giant thymic cyst that was successfully treated by percutaneous aspiration and ethanol injection. The patient had complained of coughing and chest discomfort for several years. A chest X-ray film revealed the shadow of a large abnormal mass in the anterior mediastinum. We diagnosed it as a thymic cyst. The patient refused surgery because of her age. We chose a less invasive therapy, namely, ethanol sclerosis of the cyst. The cyst was successfully treated without any complications, and no recurrence was found at the one-year follow-up. This therapy may be one of the best treatments for thymic cysts, especially in very elderly patients.

Aged↗

PubMed1997

Primary intracranial germ cell tumors: a clinical analysis of 153 histologically verified cases.

The authors analyzed 153 cases of histologically verified intracranial germ cell tumors. The histological diagnosis was germinoma in 63 patients (41.2%), teratoma in 30 (19.6%), and other types of tumors in 60 patients (39.2%). The patients were treated by a consistent policy of surgical removal with histological verification followed by radiation therapy with or without chemotherapy. The 10- and 20-year survival rates of patients with pure germinoma were 92.7% and 80.6%, respectively. The 10-year survival rates of patients with mature teratoma and malignant teratoma were 92.9% and 70.7%, respectively. Patients with pure malignant germ cell tumors (embryonal carcinoma, yolk sac tumor, or choriocarcinoma) had a 3-year survival rate of 27.3%. The mixed tumors were divided into three subgroups: 1) mixed germinoma and teratoma; 2) mixed tumors whose predominant characteristics were germinoma or teratoma combined with some elements of pure malignant tumors; and 3) mixed tumors with predominantly pure malignant elements. The 3-year survival rates were 94.1% for the first group, 70% for the second group, and 9.3% for the third group, and the differences were statistically significant. Twenty-six patients with malignant tumors received chemotherapy that consisted of cisplatin and carboplatin combinations with or without radiation therapy. However, chemotherapy was not significantly more effective than radiation therapy alone. From these treatment results, the authors classified tumors into three groups with different prognoses and proposed a treatment guideline appropriate for the subgroups.

Adolescent↗

PubMed1997

[Investigation of the usefulness of CYFRA 21-1 as a tumor marker in squamous cell carcinomas of the head and neck].

It has been demonstrated that CYFRA 21-1 (ELISA kit), which recognizes the soluble cytokeratin 19 fragment, is useful for assessing circulating tumor antigens in sera of patients with lung cancer. In this study, we compared the clinical significance of this new marker with the established squamous cell carcinoma antigen (SCC Ag), using sera from patients with head and neck malignant disease, healthy controls, and supernatants of established cell lines derived from squamous cell carcinomas and adenocarcinomas. The subjects were: Group A, 39 patients with malignant disease of the head and neck. Group B, 11 patients considered to be tumor-free after treatment. Group C, 67 patients with benign disease or healthy volunteers. Culture supernatants: 11 cell lines established from squamous cell carcinomas and adenocarcinomas. Serum levels of CYFRA 21-1 and SCC Ag of group A were significantly higher than those of group C. This finding suggests that CYFRA 21-1 is useful as a tumor marker as well as SCC Ag. CYFRA 21-1 and SCC Ag levels of patients in group A at the early and progressive stages of disease were comparable to the levels in group C. Both tumor markers are therefore useful for diagnosis of in the early stage of cancer. We attempted to set a cut-off level of CYFRA 21-1. The sensitivity of CYFRA 21-1 is higher than that of SCC Ag, especially in patients in the early stage of the disease. This finding indicates that the CYFRA 21-1 is preferable to SCC Ag as a tumor marker for the diagnosis of patients even in the early stages of malignant disease. The levels of CYFRA 21-1 in culture supernatants derived from tumor cell lines are higher than those of SCC Ag in all cell lines. The levels of CYFRA 21-1 are measurable, with levels varying with the cell line. There appears to be no correlation between the level of CYFRA 21-1 and the character of the cell lines, but this issue remains to be further investigated.

Adult↗

PubMed1997

[Influence of atrioventricular delay on pulmonary capillary wedge pressure in two patients with hypertrophic obstructive cardiomyopathy during dual chamber pacing].

Recently, dual chamber pacing has been proposed as a new treatment for left ventricular outflow tract obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM). However, dual chamber pacing may be detrimental to both systolic and diastolic function of the left ventricle, particularly at short atrioventricular (AV) delay. A 45-year-old man and a 58-year-old woman with HOCM underwent transesophageal echocardiography and hemodynamic study at various AV delays (50-200 msec). In both patients, shortening of AV delay increased pulmonary capillary wedge pressure. The transesophageal echocardiographic study showed a remarkable shortening of the ventricular filling duration at atrial systole and an increase of pulmonary venous reversal at short AV delay (50-100 msec). Therefore, short AV delay was detrimental to diastolic filling and thus increased pulmonary capillary wedge pressure. Transesophageal echocardiographic study may be helpful for defining the optimal AV delay more precisely in HOCM during dual chamber pacing.

Blood Flow Velocity↗