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Biomedical subjects

Y Kitayama

Publications and source records attributed to Y Kitayama.

At least 19 recordsLinked to original sources
PubMed2001

Microsatellite instability of papillary subtype of human gastric adenocarcinoma and hMLH1 promoter hypermethylation in the surrounding mucosa.

Gastric cancer has striking heterogeneity in histological pattern, cellular phenotype, genotype, biomarkers, and biological behavior. We focused on the specific morphological papillary phenotype of gastric adenocarcinoma and attempted to identify its distinct molecular characteristics. In our comparative study, early stage papillary (papillary-dominant) gastric cancer showed a significantly higher and more widespread high-frequency microsatellite instability (MSI-H) than other morphological types. Analysis of mutations in a panel of five putative microsatellite instability (MSI)-associated genes in the MSI-H cases revealed that papillary or papillary-dominant cancer displays a unique profile of mutations compared to profiles previously reported in gastric cancer. Immunohistochemical staining and methylation analysis revealed that silencing of hMLH1 by methylation in its promoter region was responsible for the failure of mismatch repair in papillary-type gastric cancer, whereas aberrant promoter methylation of hMLH1 was not found in any cases without the unique mutator phenotype. Promoter hypermethylation of the hMLH1 genes was found to a lesser degree in the adjacent non-tumor mucosa in four of the 10 cases with tumor having the mutator phenotype. Microsatellite instability itself could not be detected in the adjacent non-tumor mucosa. Inactivation of hMLH1 expression by promoter hypermethylation may be an early event in carcinogenesis of this type of gastric cancer, preceding the development of the clear MSI phenotype of papillary carcinoma.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Usefulness of cord-blood harvesting for autologous transfusion in surgical newborns with antenatal diagnosis of congenital anomalies.

BACKGROUND/PURPOSE: The risks of homologous transfusion and the effectiveness of predeposit autologous transfusion have been described. The authors examined the clinical usefulness of cord-blood harvesting for autologous transfusion in newborns who had congenital anomalies antenatally diagnosed that would require surgical intervention at or near the time of delivery. METHODS: Of 112 cases of antenatal diagnosis of congenital anomalies, 50 mothers gave informed consent and enrolled in this study. Cord-blood was withdrawn immediately after clamping of the umbilical cord and was used for autologous transfusion in newborns within the first 3 days postpartum. RESULTS: A mean of 72 +/- 54 mL of cord-blood was harvested (27 +/- 18 mL/kg). While preserving cord-blood for 3 days at 4 degrees C, no signs of clot formation or hemolysis were observed. The harvested cord-blood included plasma-free Hb ranging from 1 to 68 (13 +/- 18) mg/dL and thrombin-antithrombin III complex ranging from 2 to 273 (18 +/- 50) ng/mL. Bacteriologic examination of the stored cord-blood showed negative cultures, except for samples from 3 newborns after vaginal delivery. A mean of 46 +/- 34 mL of cord-blood was used in 26 patients for autologous transfusion. No significant complications related to cord-blood transfusion were recognized clinically. CONCLUSIONS: Autologous cord-blood transfusion has the potential to be a useful alternative to homologous transfusion in newborns requiring surgery. Adequate collection and storage techniques for cord-blood must be developed. J Pediatr Surg 36:851-854.

Blood Preservation↗
PubMed2000

A kaiC-interacting sensory histidine kinase, SasA, necessary to sustain robust circadian oscillation in cyanobacteria.

Both regulated expression of the clock genes kaiA, kaiB, and kaiC and interactions among the Kai proteins are proposed to be important for circadian function in the cyanobacterium Synechococcus sp. strain PCC 7942. We have identified the histidine kinase SasA as a KaiC-interacting protein. SasA contains a KaiB-like sensory domain, which appears sufficient for interaction with KaiC. Disruption of the sasA gene lowered kaiBC expression and dramatically reduced amplitude of the kai expression rhythms while shortening the period. Accordingly, sasA disruption attenuated circadian expression patterns of all tested genes, some of which became arrhythmic. Continuous sasA overexpression eliminated circadian rhythms, whereas temporal overexpression changed the phase of kaiBC expression rhythm. Thus, SasA is a close associate of the cyanobacterial clock that is necessary to sustain robust circadian rhythms.

Adaptation, Physiological↗
PubMed2000

Meconium peritonitis in utero.

To clarify the relationship between clinical features in utero and postnatal prognosis, 20 fetuses who underwent ultrasonic (US) evaluation for meconium peritonitis (MP) over a 17-year period were reviewed. According to final US findings in utero, patients were classified into three types. Type I (massive meconium ascites) was noted is 5 cases, type II (giant pseudocyst) in 4, and the other 11 were classified as type III (calcification and/or small pseudocyst). Abdominal calcifications were identified in only 5 cases (2 type I, 1 type II, 2 type III). Seven fetuses who had associated polyhydramnios (1 Type I, 1 Type II, 2 Type III) and fetal hydrops (3 Type II) were delivered before 36 weeks' gestation. Cardiopulmonary resuscitation at birth was required in 9 cases (5 type I, 4 type II) who underwent abdominal drainage before delivery and/or immediately after birth. Although dilatation of the intestine was identified in 10 fetuses (2 type II, 8 Type III), 18 had intestinal atresia and 2 had fecal obstruction of the distal ileum. Four infants (2 type I, 1 type II, 1 type III) died of respiratory failure and postoperative complications. These results indicated that careful fetal US may be useful for perinatal management of MP.

Ascites↗
PubMed2000

Does topical cooling alleviate ischemia/reperfusion injury during inflow occlusion in hepatectomy? Results of an experimental and clinical study.

This study was undertaken to evaluate whether topical cooling can alleviate ischemia/reperfusion injury, after continuous inflow occlusion during hepatectomy. Using a canine model of 70% partial liver ischemia (60 min), alteration in the subcellular (cytoplasm, mitochondria, nucleus) elements calcium, sodium, potassium, and chloride, and liver functions following reperfusion were compared between control livers and livers subjected to topical cooling down to 23 degrees +/- 4.9 degrees C by seeding ice slush over the ischemic lobe. The elements were determined by X-ray microanalysis using liver biopsy specimens. A similar clinical study was undertaken examining ten patients with hepatocellular carcinoma and chronic liver disease who underwent right-sided segmentectomy under continuous right inflow occlusion, five of whom were given topical cooling and five of whom were not. In the experimental study, postreperfusion worsening of liver function tests was significantly suppressed in the cooling group, which was associated with the suppression of subcellular Ca, Na, and Cl increases and K decreases after reperfusion. In the clinical study, the occlusion time was significantly longer in the hypothermic patients than in the normothermic patients, but no significant differences in postoperative liver function or postischemic increases in Ca, Na, or Cl and decreases in K were observed. These experimental and clinical findings suggest that topical cooling alleviates ischemic insult and enhances safe prolonged inflow occlusion.

Aged↗
PubMed2000

Pexis of the great vessels for patients with tracheobronchomalacia in infancy.

BACKGROUND/PURPOSE: Aortopexy has been established as a surgical treatment for tracheobronchomalacia in infancy. However, the effects in patients with bronchial involvement remain controversial. The authors performed aortopexy and pexis of the pulmonary artery trunk (PApexy) for patients with tracheobronchomalacia. METHODS: Between 1992 and 1997, 14 infants with tracheobronchomalacia were treated. Patients ranged in age from 4 months to 7 years (median, 3.5 years). Using patients' records, intraoperative bronchofiberscopic results and clinical outcomes were analyzed retrospectively. RESULTS: Concerning tracheomalacia, aortopexy eliminated airway collapse as shown by intraoperative fiberscopic results and clinical outcome in 4 patients. Regarding tracheobronchomalacia, aortopexy eliminated collapse of the trachea and the right main bronchus in 3 patients but did not improve collapse of the lower half of the left main bronchus in 3 patients, which was eliminated by PApexy. Aortopexy eliminated airway collapse of the left main bronchus in 1 of 3 patients with bronchomalacia. PApexy eliminated collapse of the lower half of the left main bronchus in 1 patient. CONCLUSIONS: These results indicate that intraoperative bronchofiberscopic results were closely correlated to the clinical outcome, and suggest that aortopexy is helpful for eliminating collapse of the right main bronchus and the proximal half of the left main bronchus and that PApexy eliminates collapse of the distal half of the left main bronchus.

Abnormalities, Multiple↗
PubMed2000

Patent ductus venosus with a hypoplastic intrahepatic portal system presenting intrapulmonary shunt: a case treated with banding of the ductus venosus.

A case of patent ductus venosus (PDV) presenting intrapulmonary shunting is described. Although retrograde venography of ductus venosus showed few intrahepatic branches, banding of PDV resulted in increased intrahepatic portal branches and disappearance of symptoms 10 months after the operation. Banding of the ductus venosus may be effective in PDV even with hypoplastic intrahepatic portal system.

Child↗
PubMed2000

Intratumor heterogeneity of centromere numerical abnormality in multiple primary gastric cancers: application of fluorescence in situ hybridization with intermittent microwave irradiation on paraffin-embedded tissue.

Our recent success in retrieving distinct fluorescence signals in response to centromere specific probing of paraffin-embedded tissues after intermittent microwave (MW) treatment provided the opportunity to analyze chromosome numbers or centromere abnormality in situ in human tumors in various clinicopathological settings. In this study, centromere numerical abnormality (CNA) was investigated by fluorescence in situ hybridization (FISH) in a case of multiple gastric cancer having intratumor histological heterogeneity. The different profiles as determined using a total of 20 specific probes on 4 multifocal lesions in the stomach confirmed the multi-clonality of these tumors. FISH with probes specific for chromosomes 10, 11, 16 and 18 revealed intratumor heterogeneity of the CNA, which corresponded to the histological heterogeneity. Our report clearly demonstrates, for the first time, intratumor heterogeneity of CNA and its association with the histological picture, and substantiates the applicability of the MW-assisted FISH protocol to paraffin-embedded pathological specimens.

Centromere↗
PubMed2000

Different vulnerability among chromosomes to numerical instability in gastric carcinogenesis: stage-dependent analysis by FISH with the use of microwave irradiation.

Numerical chromosomal abnormalities are a well known characteristic of human cancer, but no "chromosome-wide investigation" encompassing almost all of the chromosomes has ever been reported. Furthermore, although the multistep process of carcinogenesis is widely accepted in human cancer, the stepwise numerical aberration of chromosomes has never been addressed. Touch preparations of 24 (male 20, female 4) surgically resected gastric cancer tissue samples in various stages in terms of depth of invasion were analyzed by fluorescence in situ hybridization using centromere-specific probes including 17 chromosomes, 1-4, 6-8, 10-12, 15-18, 20, X, and Y. Microwave irradiation was performed to increase the sensitivity and specificity of the signal. The depth of the tumor invasion in the gastric wall and histological subtypes were recorded by viewing the histology of the adjacent portion. Numerical chromosomal abnormalities of chromosomes 1 and 2 were found most frequently and from the early stage of gastric cancer. The abnormalities observed were limited to chromosomes 1, 2, 4, and 20 in tumors invading to the middle layer of the submucosa of the gastric wall, but these became more extensive, involving almost all of the chromosomes investigated when the tumor had invaded beyond the proper muscle of the gastric wall. Centromeric numbers of chromosomes 3 and 18 were exceptionally stable even after the tumor progressed to advanced stage. These profiles of the sequential process of numerical chromosomal abnormality were similar in both mucocellular and tubular-type gastric cancer, but the prevalence was significantly lower in the mucocellular type (39.0% versus 68.0%). On the basis of fluorescence in situ hybridization analysis of 17 different chromosome centromeres in gastric cancer in various stages, we conclude that the earliest events in gastric carcinogenesis in terms of chromosomal abnormality occur in chromosomes 1 and 2 and that chromosomal numerical aberrations expand in a stepwise manner with cancer progression.

Adult↗
PubMed1999

Dynamics of portal and peripheral endothelin-1 in hepatic resection and its implication.

BACKGROUND: The liver and portal circulation contribute to production and clearance of endothelin-1 (ET-1). This study was undertaken to investigate what variables relate to the dynamics of ET-1 in hepatic resection and its clinical implication. PATIENTS AND METHODS: On 20 patients with (n = 8) or without (n = 12) chronic liver disease who underwent hepatic resection, peripheral arterial and portal venous ET-1 were serially measured to determine a correlation with pre-, intra-, and postoperative variables. RESULTS: The preoperative factors with which the portal ET-1 showed a positive correlation were the indocyanine green retention rate at 15 min (ICG R15) and portal venous pressure. The ET-1 clearance, as calculated from the difference between the portal and the peripheral ET-1 concentrations, was also correlated with the ICG R15. The peripheral ET-1 elevated significantly in the patients with increasing intraoperative blood loss or hepatic inflow occlusion. An increase in the portal ET-1 was correlated with an elevation of portal venous pressure after hepatectomy. Postoperative increase in serum bilirubin was closely correlated with the peripheral ET-1 at closure. CONCLUSION: The peripheral and portal ET-1 are correlated with not only preoperative hepatic reserve and portal venous pressure but also invasiveness of hepatectomy and postoperative course.

Blood Loss, Surgical↗
PubMed1999

Clinical significance of the lung/thorax transverse-area ratio in fetuses with cystic lung disease.

We examined the clinical significance of the lung-thorax transverse-area ratio (L/T) in fetuses with cystic lung disease (CLD). The transverse section of the thorax was analyzed at the level of the 4-chamber view of the heart. L/T was calculated as the bilateral normal lung area divided by the thoracic area. Within a 9-year period, ultrasonography was performed in 15 fetuses with CLD, 13 of which were histologically diagnosed: congenital cystic adenomatoid malformation of the lung (CAM; n = 8), pulmonary sequestration (n = 4), and bronchial atresia (n = 1). Although the initial L/T measurement (29.6 +/- 4.2 weeks) showed significantly lower values than in the controls, the final measurement (36.4 +/- 1. 6 weeks) indicated that the L/T in CLD excluding CAM was significantly higher than that in CAM. Six patients with a final L/T of less than 0.21 required mechanical ventilation immediately after birth. Two of these patients died, and the autopsy findings indicated pulmonary hypoplasia. In these cases, a significant correlation was observed between the maximal value of L/T and preductal alveolar-arterial oxygen difference (A-aDO(2)), although the final L/T was not correlated to A-aDO(2). These results indicate that serial measurements of L/T may be useful in the diagnosis of CLD and may help to predict postnatal respiratory conditions.

Bronchopulmonary Sequestration↗
PubMed1999

Ovarian mucinous cystadenocarcinoma with yolk sac tumor in a 71-year-old woman.

An ovarian mucinous cystadenocarcinoma admixed with a component of yolk sac tumor was encountered in a 71-year-old woman, the first such tumor to be reported. The preoperative serum level of alpha-fetoprotein was elevated (55.6 ng/mL). A right ovarian cystic tumor, 8 cm in maximal dimension, was removed and found to have a solid component. Microscopically, the cystic lesion was a mucinous cystadenocarcinoma, whereas the solid portion was typical yolk sac tumor with microcystic, reticular, and labyrinthine patterns, Schiller-Duval bodies, scattered giant cells with bizarre nuclei, and intracellular and extracellular hyaline globules. There was no evidence of other germ cell tumor components. Yolk sac tumor showed positive reactions for alpha-fetoprotein, carcinoembryonic antigen, and alpha-1-antitrypsin but was negative for CA125, CA19-9, and human chorionic gonadotrophin. The patient died of recurrent tumor 6 months postoperatively without response to combination chemotherapy.

Aged↗
PubMed1999

Amplification of FISH signals using intermittent microwave irradiation for analysis of chromosomal instability in gastric cancer.

Gastrointestinal tract tumours are notorious for their difficulty in relation to conventional cytogenetic analysis. In particular, necrosis, the presence of stromal inflammatory and other cells, and poor attachment of tumour cells have led to problems with the quality and reliability of cytogenetic preparations, even with the recently developed fluorescence in situ hybridisation (FISH) technique. Furthermore, background autofluorescence masks the weak hybridisation signals in the nuclei. To overcome this problem, brief microwave treatment was applied for the identification of centromeres by in situ hybridisation in gastric cancer cells. Using this technique, a panel of 17 centromeric specific alpha-satellite probes was used to detect chromosomal instability in these cells. Lymphocyte controls and cancer cells subjected to irradiation achieved the hybridisation threshold in 30 minutes, providing a significant difference when compared with the non-irradiated samples (mean (SD) frequency of diploid cells 97% (2.1%) v 76% (4.6%), respectively). Therefore, this protocol of intermittent microwave treatment is recommended as a simple, rapid, and highly reproducible technique for application to various types of probe. It also gives well defined hybridisation signals and reduces background "noise".

Centromere↗