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Biomedical subjects

S Suita

Publications and source records attributed to S Suita.

At least 127 records · Page 7Linked to original sources
PubMed1996

The relationship between the adenine nucleotide metabolism and the conversion of the xanthine oxidase enzyme system in ischemia-reperfusion of the rat small intestine.

The time course of the energy metabolism after reperfusion, the relationship between the conversion of xanthine dehydrogenase to xanthine oxidase (D-to-O conversion) during ischemia, and the changes of the energy metabolism after reperfusion were studied using an ischemia-reperfusion model in the small intestine of the rat. The rat jejunum underwent an occlusion of the superior mesenteric artery and vein for either 30 minutes (group 1, n = 6) or 90 minutes (group 2, n = 6) with collateral interruption, and then it was reperfused. The contents of the adenine nucleotides in the small intestine of the rat were measured by high-performance liquid chromatography (HPLC) before ischemia, and 30, 60, and 90 minutes of ischemia, as well as 30, 60, 120, and 180 minutes after reperfusion. The recovery level of adenosine triphosphate (ATP) in group 1 (6.05 +/- 0.80 mumol/g dry weight) 30 minutes after reperfusion was significantly higher than that in group 2 (2.28 +/- 1.12 mumol/g dry weight) (P < .001). In addition, the ATP content after reperfusion in group 2 did not change from 30 to 180 minutes after reperfusion. The D-to-O conversion during ischemia in group 1 was not significantly greater than that before ischemia; however, that of group 2 did increase significantly during ischemia (P < .005). These results suggest that the tissue damage from ischemia-reperfusion injury after reperfusion under 90 minutes' ischemia is accomplished within the first 30 minutes after reperfusion. Therefore, the ATP level at 30 minutes after reperfusion may be useful for the evaluation of intestinal viability. Thus, the conversion of the xanthine oxidase enzyme system might play an important role in the expression of ischemia-reperfusion injury.

Adenine Nucleotides↗
PubMed1996

Long-term results of short segmental syngeneic small intestinal transplantation: comparison of jejunal and ileal grafts.

A short-segment intestinal graft is favorable to reduce the rate of rejection and the incidence of graft-versus-host disease in recipients of small intestine transplantation. To determine whether a jejunal or an ileal graft is preferable with respect to intestinal morphology and function, syngeneic two-step small intestinal transplantations were performed using male Lewis rats (RT1(1)). They were divided into two groups according to the small intestine donor site (group 1 received 10 cm of jejunum; group 2 received 10 cm of ileum). There was no significant difference in the survival rate or weight gain between the two groups. Nearly all the hematologic findings, serum nutritional parameters, and results of liver function tests were normal for both groups. The only difference was that the serum total bile acid level was significantly higher in group 2. Fifty weeks after transplantation, the graft mucosa showed normal architecture, with adaptive hyperplasia of villi and crypt noted through histological study. The villus height of group 1 was 595 +/- 64 microns (control, 452 +/- 67 microns); that of group 2 was 732 +/- 53 microns (control, 217 +/- 20 microns). The crypt depth of group 1 was 228 +/- 35 microns (control, 165 +/- 24 microns); that of group 2 was 320 +/- 19 microns (control, 102 +/- 19 microns). These compensatory changes were more pronounced in group 2. The authors conclude that, on the basis of long-term functional capacity, there was no significant difference between jejunal and ileal grafts, and that both segments were suitable for transplantation. However, the ileal graft was considered to be better with respect to morphological adaptation.

Animal Nutritional Physiological Phenomena↗
PubMed1996

Extraabdominal fixation of the gubernaculum inhibits testicular descent in newborn rats.

Within 48 hours after birth, newborn rats were anesthetized, and the distal tip of the gubernaculum was exposed extraabdominally, then fixed to the fascia of the groin on the left or the right side under a dissecting microscope (6x). In the sham-operated rats, the distal tip of the gubernaculum was merely exposed. Nonoperated rats were used as controls. In 60- to 90-day-old operated rats (n = 42), all testes were located in the superficial inguinal position, and the incidence of cryptorchidism was 100% on the operated side. In the sham-operated rats (n = 28), 27 of 28 testes descended into the scrotum, and one was located in the perineum; the incidence of cryptorchidism was 3.6% on the operated side. All testes also descended into the scrotum, and the incidence of cryptorchidism was 0% in controls (n = 20). The incidence of cryptorchidism was significantly higher among operated rats than among sham-operated or control rats (P < .001). The testicular weight and the germinal epithelia of the cryptorchid testes were significantly lower than those of the scrotal testes in both sham-operated and control rats. Therefore it is suggested that the extraabdominal fixation of the distal tip of the gubernaculum in newborn rats induces cryptorchidism. The present model is considered to be a simple and useful one to investigate the process of testicular maldescent and inhibited growth of the testis in cryptorchidism.

Animals↗
PubMed1996

Mass screening for neuroblastoma: quo vadis? A 9-year experience from the Pediatric Oncology Study Group of the Kyushu area in Japan.

Since 1985, a nationwide program of mass screening for neuroblastoma has been available for 6-month-old infants throughout Japan. From 1985 to 1993, the authors studied 285 patients with neuroblastoma among their regional population of 15 million. There was an increase in the total number of patients per year in comparison to the previous 6-year period (1979 to 1984). However, no significant difference was noted in the number of patients older than 1 year or in the incidence of advanced-stage (stages III and IV) unscreened cases. The majority of neuroblastomas in the screened group showed favorable biological factors, even in the advanced stages. However, there was a small group with histologically and/or biologically unfavorable factors; five of 115 had amplified N-myc oncogene, four of 74 showed unfavorable Shimada histological findings, and three of 33 had an unfavorable DNA ploidy pattern. One case from this group with unfavorable factors died of the tumor. 3) Thirty-eight cases were negative at the time of mass screening, but later presented with neuroblastoma. Most of them were diagnosed between 1 and 3 years of age, and 30 of the 38 cases (78.9%) were advanced stage with unfavorable prognostic factors. Thus, the authors conclude that mass screening at 6 months can detect a selected population of infants with neuroblastoma; some of the tumors may represent subclinical masses destined for spontaneous regression. However, some tumors with unfavorable factors have been detected by mass screening before progression and/or dissemination. Infants in this group are considered to benefit most from early diagnosis and treatment.

Adolescent↗
PubMed1996

Maternal dexamethasone treatment enhances the expression of surfactant apoprotein A in the hypoplastic lung of rabbit fetuses induced by oligohydramnios.

Previously the authors reported that oligohydramnios induced lung hypoplasia in rabbit fetuses and showed that sustained oligohydramnios, which was induced by amniotic shunting from gestational sacs into the maternal peritoneal cavity between 23 and 30 days' gestation, significantly retards not only lung structural growth but also the functional development of alveolar type II cells in surfactant apoprotein A (SP-A) expression. In the present study, the authors examined, both immunohistochemically and morphometrically, whether the maternal administration of dexamethasone restored SP-A synthesis in fetal hypoplastic lungs. The fetal rabbits were treated through maternal administration of dexamethasone (0.25 mg/kg/d) or saline 48 and 24 hours before delivery, at 30 days' gestation. The ratio of lung weight to body weight was significantly greater for the dexamethasone-treated fetuses compared with the saline-treated fetuses in both the shunted and the nonshunted groups (P < .05). Compared with the lungs of the saline-treated fetuses, those of the dexamethasone-treated fetuses had a statistically significant increase in SP-A expression, namely the number of SP-A-positive type II cells per unit area (P < .001), the ratio of SP-A-positive cells to the total number of cells (P < .01), and the percentage of SP-A-positive area per unit area (P < .05) in the shunted group. An increase in the ratio of SP-A-positive area to lung interstitial was found for the shunted group. However, similar findings were not observed in the nonshunted group. The results suggest that maternal dexamethasone treatment accelerates the functional development of alveolar type II cells in SP-A expression, even in hypoplastic lungs induced by oligohydramnios.

Animals↗
PubMed1996

The prognostic importance of nuclear morphometry and the MIB-1 index in rhabdomyosarcoma [corrected].

Both nuclear morphometry and an evaluation of the cell proliferative activity have been reported to be useful tools in predicting prognosis in malignant tumors. There have been few reports, however, on rhabdomyosarcoma regarding these evaluative techniques. We performed nuclear morphometry on 51 tumor specimens obtained either by biopsy or by resection of primary and untreated rhabdomyosarcomas, and we then evaluated MIB-1 staining on 25 of the 51 specimens. The morphometric analysis was semiautomatically performed on hematoxylin- and eosin-stained sections by using a personal computer. The areas, perimeters, and lengths of the major and minor axes of the best fitting ellipse of the nuclei were all measured. In addition, the Form Ell (nuclear ellipsoidity score: minor axis/major axis) was calculated. Using the monoclonal MIB-1 antibody, which detects Ki-67 antigen in formalin-fixed, paraffin-embedded tissue, immunohistochemical studies were performed. The values of the major and minor axes and the Form Ell showed significant differences between each histologic subtype whereas the values of nuclear areas did not. We defined the nucleus whose Form ELL was smaller than 0.25 as spindle-shaped nuclei and then divided all cases into two groups on the basis of the ratio of the spindle-shaped nuclei to the total number of nuclei of the tumor cells. The group with the higher ratio showed a significantly better prognosis (P < 0.05). The same trends were also found in the specimens with an embryonal subtype. Nuclear morphometry was a useful tool in predicting prognosis. In particular, the appearance of spindle tumor cells in rhabdomyosarcoma correlated with a better prognosis.

Adolescent↗
PubMed1996

Urachal remnants.

Although urachal remnants rarely are observed clinically, they often give rise to a number of problems such as fatal infection and late malignant changes. Therefore, a total assessment of the disease with a particular focus on embryology, anatomy, and clinical symptoms, as well as the most advisable treatment, is called for. The authors report on 33 previously experienced cases and discuss the problems involved in both the diagnosis and treatment of these anomalies.

Child↗
PubMed1995

Role of ultrasound in managing neuroblastoma detected by mass screening: a proposed ultrasonographic grading for children with neuroblastoma.

The ultrasonographic (US) findings of 25 infant cases detected by the Japanese mass screening program for neuroblastoma (NB) were reviewed. The following results were obtained: An identification of the primary site was possible in 96% of the cases with abdominal US. An estimation of the tumor weight was possible based on the mass volume, which was calculated from US measurements. With the combination of the estimated mass volume, local involvement, and distant metastasis, the US grading of NB was possible and closely corresponded to the surgical staging (84%). The NB cases of adrenal origin at U1a, with a mass volume of less than 16 mL, were all found to be stage I and presented the possibility for spontaneous regression.

Adrenal Gland Neoplasms↗
PubMed1995

The significance of cytological examination on reperfusion in rat small intestinal transplantation.

We examined the cytology of the exudate in preserved intestinal grafts on reperfusion and compared it with the histological findings in rat small intestinal transplantation. The jejunal graft was harvested from the Lewis rat and was preserved in University of Wisconsin solution for 6, 12, 24 and 48 h at 4 degrees C (n = 6, in each group) and was then syngeneically transplanted. On reperfusion, the exudate was collected and studied cytologically. Full thickness biopsies were performed at the end of the preservation and at 30 min after reperfusion for histological examination. Histological examination after reperfusion showed that the crypt layer was preserved until 24 h. However, it was destroyed by 48 h preservation. The cytological findings correlated with the depth of tissue injury shown histologically. The degeneration of villus epithelial cells, the decrease in the content of mucin in both the goblet cells as well as villus cells, and the appearance of crypt cells are all considered to be signs of poor graft viability. Cytological examination is therefore recommended as an effective, non-invasive and real-time method for evaluating graft viability just after reperfusion in small intestinal transplantation.

Adenosine↗
PubMed1995

Extralobar pulmonary sequestration mimicking cystic adenomatoid malformation in prenatal sonographic appearance and histological findings.

An infant girl with extralobar pulmonary sequestration (PS) composed of congenital cystic adenomatoid malformation (CCAM)-like structure is presented. Initially, the antenatal sonographic findings indicated CCAM. The macroscopic findings of the resected specimen were compatible with extralobar PS; however, the microscopic findings showed cystic structure mimicking type II CCAM. The combination of PS and CCAM is rare, and it is likely that the embryological origin is common to both. There is confusion in the classification of these two congenital anomalies. In this report, the histological and sonographic findings of PS and CCAM are discussed.

Adult↗
PubMed1995

Neuroblastoma in infants aged less than 6 months: is more aggressive treatment necessary? A report from the Pediatric Oncology Study Group of the Kyushu area.

Infants with neuroblastoma are known to have a better prognosis than older children. In Japan in 1985, mass screening for neuroblastoma in infants aged 6 months was introduced. With this policy, there has been an increase in the number of patients seen with neuroblastoma between 6 and 11 months of age. In a previous report the authors described the management and prognosis of infants with disease detected by mass screening, but there is still little information regarding the strategies of management for infants with neuroblastoma aged less than 6 months. The authors analyzed the data regarding 27 patients aged less than 6 months registered in their region (population 15 million) from 1985 to 1992, and compared it with that of the previous 8-year period. In the younger age group, there was a significantly higher rate of advanced disease stages (III and IV). In spite of the variation in treatment related to the choice of individual institutions, infants with stages I, II, and III disease had a good outcome, suggesting that aggressive chemotherapy is not necessary unless poor prognostic factors are present. One patient with stage IV disease died of disseminated disease and one with stage IVs and 22 copies of N-myc oncogene also died of tumor relapse in spite of aggressive chemotherapy. It is therefore concluded that the prognosis in infants with stage IV and IVs neuroblastoma under the age of 6 months is not as good as had previously been believed, and that such patients, therefore, require special consideration.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

The effect of the excision of future scrotal skin on testicular descent in neonatal rats: a new experimental model of cryptorchidism.

The ingunoscrotal skin of neonatal rats was widely excised on either the right or left side to examine the role of the scrotum in testicular descent. At the age of 10 days, gubernacular migration was observed to be significantly inhibited on the operated side in comparison with that on the nonoperated side. At the age of 60 to 90 days, 12 of 17 testes on the operated side were located in the superficial inguinal position, 2 were in the perineum, and another 3 had descended into the contralateral nonoperated scrotum. All the testes descended into the scrotum on the nonoperated side and in the normal control rats. Though the histological development was remarkably inhibited in the cryptorchid testis, the contralateral descended testis did show the same histological appearance as that of the control testes in 90-day-old rats. This new model of cryptorchidism is considered to provide a simple technique for investigating the mechanism of testicular descent and the impaired development of the testes in cryptorchidism.

Animals↗
PubMed1995

The protective effect of hyperbaric oxygenation on the small intestine in ischemia-reperfusion injury.

Hyperbaric oxygenation has been used as the method of treatment in several ischemic diseases, but its effectiveness still remains controversial. The authors investigated the effect of hyperbaric oxygenation on ischemia-reperfusion injury of the small intestine using a rat model. Wistar King A Makino (WKAM) rats were subjected to 120 minutes of superior mesenteric artery occlusion before reperfusion, with 90 minutes of hyperbaric oxygenation (two absolute atmospheric pressure in an experimental hyperbaric chamber) during ischemia in group A and immediately after reperfusion in group B, and no hyperbaric oxygen was provided to group C. Jejunal samples 1.5 cm in length were taken at the end of ischemia in all groups, at 30 minutes after reperfusion in groups A and C, and at 120 minutes after reperfusion in groups B and C, for the measurement of adenine nucleotides (high-performance liquid chromatography method) and for histological examination (hematoxylineosin [HE] staining). The survival rate was significantly higher in group A than in group C. The amount of adenosine triphosphate in the samples was not significantly different among the three groups, whereas the energy charge at the end of ischemia was significantly higher in group A than in group C. Histologically, the damage to the mucosa and the longitudinal muscle layer decreased in group A compared with that observed in groups B and C. These results suggest that hyperbaric oxygenation during ischemia is able to ameliorate ischemia-reperfusion injury in the rat small intestine.

Animals↗