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Biomedical subjects

S Ogata

Publications and source records attributed to S Ogata.

265 records · Page 15Linked to original sources
PubMedDate not supplied

A rat model to study the role of STn antigen in colon cancer.

Expression of the mucin-associated sialyl-Tn (STn) antigen has been associated with a decreased survival in patients with colorectal, gastric, and ovarian cancer. To better understand the role of STn antigen in tumor biology, we developed STn(+) (called LP) and STn(-) (called LN) clonal cell lines from a parental metastatic rat colon carcinoma cell line (LMCR). Both derivative cell lines exhibited identical proliferation rates in vitro. LP cells strongly expressed STn antigen both in vitro and in vivo, and were poorly tumorigenic when given to syngeneic rats. LN cells did not express STn antigen in vitro, but as in vivo tumors these cells rapidly acquired STn expression, readily formed tumors, and were highly lethal. When rats were given an otherwise lethal inoculum of i.p. LN cells, pre-immunization with synthetic STn antigen conjugated to keyhole limpet hemocyanin (STn-KLH) resulted in a 60% survival rate. When LN cells were injected subcutaneously in the presence of STn-KLH-sensitized lymphocytes, tumor growth was decreased. Distribution of STn antigen in normal organs of host rats is quite similar to that of humans. This model mimics human disease and should facilitate studies of mucin-associated antigens in tumor biology and the development of immunotherapeutic agents based on mucin-related antigens.

Animals↗
PubMedDate not supplied

Early intrauterine presence of congenital dislocation of the knee.

We report the histologic findings of congenital dislocation of both knees of a 19.5-week-old spontaneously aborted fetus. Grossly and histologically, both knees were grade II congenital dislocations (subluxation), which are characterized by hyperextension of the knee with rotatory subluxation. Comparing the morphologic changes to age-matched normal controls allowed us to distinguish between primary and secondary changes. The most impressive fetal abnormalities were partial fibrosis of the quadriceps, absence of a suprapatellar pouch and incomplete patellofemoral joint cavitation. The presence of these findings suggests that they most likely cause, and do not result from, dislocation. This specimen is the first preterm fetus to be described with the features of congenital dislocation of the knee of any type.

Abortion, Spontaneous↗
PubMedDate not supplied

Kindled amygdaloid seizures in rats cause immediate and transient increase in protein kinase C activity followed by transient suppression of the activity.

Protein kinase C (PKC) activity in hippocampus and amygdala was measured during kindled seizures and 30 min, 3, 24, and 48 h, and 2 weeks after seizures in amygdaloid-kindled rats. Sham-operated rats not subjected to kindling were used as controls. During kindled seizures, membrane-bound PKC activity in bilateral hippocampi was significantly increased, with a slight reduction in cytosolic PKC activity, but there was no change in either membrane-bound or cytosolic PKC activity in bilateral amygdala. Thirty minutes after seizures, PKC activity in both fractions was significantly increased in bilateral hippocampi and amygdala. Three hours after seizures, PKC activity in both fractions was markedly decreased in bilateral hippocampi. In bilateral amygdala, a similar and significant decrease in membrane-bound PKC activity was noted, with no marked change in the cytosolic fraction. Twenty-four hours after seizures, a significant decrease in membrane-bound PKC activity in bilateral hippocampi and amygdala was again noted, although cytosolic PKC activity was unchanged. Forty-eight hours after the seizures, PKC activity in both fractions had returned to control levels. Two weeks after the last seizure, there was no significant change in PKC activity in either fraction in any region, except for a slight increase in membrane-bound PKC activity in unilateral hippocampus contralateral to the kindled amygdala. These results suggest that kindled amygdaloid seizures cause an immediate and transient increase in PKC activity in limbic structures, followed by suppression of enzyme activity, and that PKC in hippocampus responds to kindled seizures more readily and preferentially than it does in amygdala.(ABSTRACT TRUNCATED AT 250 WORDS)

Amygdala↗
PubMedDate not supplied

Dose-dependent effect of an oral adsorbent, AST-120, in patients with early chronic renal failure.

We evaluated the dose dependence of an oral adsorbent, AST-120, in 31 patients with early chronic renal failure (baseline serum creatinine: 1.2-3.0 mg/dl). Twenty-three patients were given AST-120 and eight patients were not. AST-120 was administered at three different maintenance doses, < 3.0 g, 3.0 g and 6.0 g/day, according to patients' ability to tolerate treatment. The treatment period was 12 months. The slope of the reciprocal of serum-creatinine concentration versus time was calculated to assess the progression of renal failure. This slope became significantly less steep after AST-120 treatment at 6.0 g/day, but did not change significantly at the other doses. These findings suggest that 6.0 g/day of AST-120 may delay the initiation of dialysis in patients with early chronic renal failure.

Administration, Oral↗
PubMedDate not supplied

A new experimental model for simultaneous evaluation of aortic and pulmonary allograft performance in a composite graft.

A model was developed in pigs for simultaneous evaluation of aortic and pulmonary allograft performance in a composite graft. The composite graft consisted of vascular prosthesis and aortic and pulmonary allografts. Following antibiotic preservation, it was anastomosed to the recipient's thoracic descending aorta by an extrapleural approach without using cardiopulmonary bypass. Aortic blood flow was completely diverted into the composite graft. All 12 recipient pigs recovered well, 4 of which were assigned for the initial study to design the suitable experimental schedule. Calcification readily occurred in the aortic allografts and aneurysmal dilatation without calcification developed in the pulmonary allografts. These morphological findings were consistent with those of previous reports. This model has several benefits. First, aortic and pulmonary allograft conduits can be implanted and evaluated simultaneously under the same conditions by making a composite graft. Second, the magnitude of the operation is minimum, and postoperative circulatory and respiratory management is uncomplicated. Third, wound infection rarely occurs, because the skin incision is made on the back. These preliminary studies suggest that this model will allow future study concerning aortic and pulmonary allograft conduits under different conditions.

Aneurysm↗
PubMedDate not supplied

Assessment of stability in children's minimally displaced lateral humeral condyle fracture by magnetic resonance imaging.

We studied 12 children who had minimally displaced lateral humeral condyle fractures. Bony gaps at the fracture site were <2 mm on the anteroposterior view of plain radiographs. To determine the stability of the fractures, we used a magnetic resonance imaging (MRI) study of the distal humerus and elbow joint. In the results, two types of fractures were classified by the extent of the fracture line in MRI. Type I showed that the line coursed from the lateral metaphysis to the growth plate but not through it. In type II, the line crossed the growth plate to enter the joint space. We concluded that the MRI study distinguished the potentially unstable fracture (type II) from the minimally displaced fracture and recommend the use of a percutaneous pin fixation for the expected unstable fracture.

Casts, Surgical↗
PubMedDate not supplied

Purification and aminopyrine monooxygenase activity of liver microsomal cytochrome P-450 from alloxan-induced diabetic rats.

We purified two diabetes-inducible and insulin-sensitive forms of cytochrome P-450, named P-450AL-1 and AL-2, from the liver microsomes of alloxan-diabetic male rats, using sodium cholate solubilization, octylamino-Sepharose 4B chromatography, and HPLC with diethylaminoethyl-5PW and hydroxyapatite columns. The purified forms gave a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, with an apparent molecular weight of 50,000 for P-450AL-1 or 48,500 for P-450AL-2. The CO-reduced spectral maximum of these forms was at 452 nm for P-450AL-1 and 451 nm for P-450AL-2. The two purified forms had the low-spin state of heme in the oxidized form. Both P-450AL-1 and AL-2 were active in the metabolism of aniline, benzphetamine, and 7-ethoxycoumarin. However, the catalytic activity of P-450AL-2 for these substrates was obviously higher than that of AL-1. The NH2-terminal sequences of P-450AL-1 and AL-2 differed from each other, and did not agree with those of the other P-450 forms purified from diabetic rats previously. Furthermore, we examined the metabolism of aminopyrine in a reconstituted system with the purified cytochromes P-450. The diabetes-inducible forms of P-450 had high aminopyrine 3-hydroxylation and low N-demethylation activities. These findings provide clear evidence supporting our previous results, which have shown an increase in 3-hydroxymethyl-2-methyl-4-dimethylamino-1-phenyl-3-pyrazolin-5-on e and a decrease in 4-monomethylaminoantipyrine in intact diabetic rats.

Amino Acid Sequence↗
PubMedDate not supplied

Costs and benefits of laparoscopic cholecystectomy: abdominal wall lifting vs. pneumoperitoneum procedure.

BACKGROUND/AIMS: Gasless laparoscopic surgery using the abdominal wall lifting (AWL) method was first developed in Japan and has been used in various surgical fields. The AWL method allows the use of conventional reusable surgical instruments. The purpose of this study was to compare the cost-effectiveness of laparoscopic cholecystectomy (LSC) using the AWL method in relation to that using pneumoperitoneum (P) method. METHODOLOGY: Retrospective analysis of 431 LSC procedures between 1991 and 2004 was performed. The two surgical groups consisted of consecutively operated patients with a diagnosis of cholecystolithiasis or gallbladder polyps. One group consisted of 224 LSC procedures performed using the P method from 1992 to 1998 and the other group comprised 207 LSC performed using the AWL method from 1998 to 2004. All instruments used in the P method were disposable, whereas trocars, scissors, dissectors, graspers and L-hook electrodes (excluding clips) used in the AWL method were reusable. Hospital expenses, length of hospital admission and complication rates were analyzed. RESULTS: Mean hospital cost per case for LSC using the AWL method (dollars 6743) was 7% less expensive than that using the P method (dolars 7215). Costs of operative equipment contributed to the difference (mean dollars 912 per case) in total cost. Conversion to open cholecystectomy occurred in 6 cases (2.9%) using the AWL method and 7 cases (3.1%) using the P method. There were no significant differences in length of hospital admission or complication rates between the two groups. CONCLUSIONS: LSC using AWL method was less expensive than that using P method. This is mainly due to the use of reusable instruments in the AWL method. If LSC is performed using the AWL method instead of using disposable equipment, considerable savings can be achieved without compromising patient safety.

Abdominal Wall↗
PubMedDate not supplied

Experimental avascular necrosis of the femoral capital epiphysis and induced subluxation of the hip in young rabbits.

We attempted to clarify experimentally the effect of hip joint incongruity on the necrotic femoral head. Twenty-four immature rabbits were divided into three groups: group I (12 rabbits), interruption of the epiphyseal artery and immobilization of the knee in extension for inducing subluxation of the hip; group II (six rabbits), interruption of the epiphyseal artery; group III (six rabbits), opening of the capsule (with preservation of the epiphyseal artery) and immobilization of the knee in extension. Radiographic examination of the hips of the rabbits in group I showed severe deformation of the necrotic femoral head with subluxation. These radiographic findings appeared similar to those of human hip joints affected with Perthes' disease.

Animals↗
PubMedDate not supplied

Clinical complications of Mycoplasma pneumoniae disease--central nervous system.

The mechanism of the neurologic complications associated with primary atypical pneumonia is unknown. To examine the ability of Mycoplasma pneumoniae to enter the brain of experimental animals, the organism was inoculated into adult and suckling mice by various routes. After intranasal infection, M. pneumoniae was isolated from brains and lungs of both groups of mice. After intracerebral inoculation, the high levels of the mycoplasma persisted for two months or more in the brains of suckling mice. In addition, after intravenous infection, the systemic spread of infection occurred in the mice treated with high doses of cyclophosphamide. Our results suggest that M. pneumoniae may be able to reach the brain via blood and it may occur with relative ease in compromised hosts.

Aerosols↗
PubMedDate not supplied

Influence of the flow rate during flushing on porcine multivisceral preservation.

The effect of flushing flow rate during multiple organ procurement (MOP) on viability of the liver, pancreas, and intestine were investigated in porcine multivisceral transplantation. Splanchnic organs were flushed in situ with 50 ml/kg of 4 degrees C UW solution via the aorta using a pump at a flow rate of 10, 30, or 50 ml/kg/min. After storage and transplantation, we assessed the clearance of hyaluronic acid (CHA) for hepatic endothelial cells function, liver enzymes, amylase, and histology. Two-day survival was 17% in the 10 ml/kg/min group and 67% in other groups. The former group had inadequate flushing out of the hepatic and intestinal grafts, resulting in aggravation of CHA and intestinal tissue injury. At the flow rate of 30 ml/kg/min, the viability and integrity of all organs were well maintained. We conclude that the optimal flushing flow rate would differ for each organ, therefore the common flow rate acceptable for any of the individual grafts should be applied in MOP.

Animals↗
PubMedDate not supplied

Small bowel rejection in isolated small bowel transplantation and in multivisceral transplantation: a comparative study in a large animal model.

The proposition that a combined graft including the liver protects other organ allografts from the same donor is well known. However, it is not evident in the clinical results. The present experiments were undertaken to compare acute small bowel rejection in isolated small bowel transplantation with multivisceral transplantation. Using 36 outbred, male Large-White pigs, isolated small bowel transplantation (SBTX: n = 9) and abdominal multivisceral transplantation (MVTX: n = 9) were performed without immunosuppression. The survival rate and blood serum samples were monitored postoperatively. In order to compare acute small bowel rejection, sequential biopsy specimens from Thiry-Vella loops were also monitored daily beginning on me 3rd day after transplantation. The specimens were scored from 0 to 3 according to the severity of the rejection. The survival rate was not significantly different. However, significant differences were noted in the cause of the death and in the pathologic changes of the small bowel. In contrast to SBTX, the small bowel rejection of MVTX was significantly delayed and less severe. The rejection score of MVTX was significantly better than SBTX from 5 postoperative days (POD) to 1 lPOD (P < 0.05). The present study demonstrated mat acute small bowel rejection of MVTX graft including the liver was delayed and less severe than that of SBTX in an outbred large animal model.

Animals↗