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Biomedical subjects

S Sawaguchi

Publications and source records attributed to S Sawaguchi.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Evaluation of second-look operations in neuroblastoma].

The roles of surgery in the treatment of neuroblastoma differ significantly according to the stage of the disease and the age of patients. Infantile neuroblastoma has high resectability and shows a favorable outcome. Moreover, infants with nonresectable neuroblastoma also have a fairly good prognosis after an appropriate treatment. Extensive local resection for tumor eradication with high surgical risk should not be performed in infants with neuroblastoma at the initiation of the treatment. Delayed surgery should be considered in such cases. The principle of the treatment for children more than 1 year of age with advanced neuroblastoma consists of intensive anticancer chemotherapy followed by delayed surgery for complete resection of the original tumor and the regional lymph nodes. Complete response of the remote metastases to the chemotherapy at surgery has been proved to be a clue for cure of the diseases. Initial surgery for reduction of the tumor burden has no advantages for the ultimate survival of the patients with advanced diseases.

Age Factors↗
PubMed1986

[Organ defects due to cancer treatment in infancy and childhood].

In infancy and childhood, as in adults, organ defect is the most direct adverse effect of cancer treatment. Anatomical defects due to surgical treatment and functional defects due to radiotherapy are the two main types. In this paper, the relationship between the radicality of surgical treatment and preservation of organ form and function are discussed with regard to the thyroid, chest wall, lung, stomach, intestine, liver, pancreas, kidney and intra-pelvic organs. The more radical the treatment, the less preservation of organ form and function. The role of surgery has been changing in accordance with the development of chemotherapeutic drugs and drug combination, and must always be reevaluated in accordance with any progress made in other treatment modalities. Some typical cases from a series of patients we have treated were presented. A neonatal case of broad right chest wall defect due to surgical removal of chondroblastoma was presented, showing our new method of chest wall reconstruction. A case of bilateral Wilms' tumor was presented, which was treated using bench surgery to prevent total removal of kidney tissue. A case of huge and infiltrative intra-pelvic rhabdomyosarcoma was also described, which was treated by tumor extirpation and 2/3 partial resection of the urinary bladder, in combination with chemotherapy and radiotherapy.

Child↗
PubMed1985

Wedge-shaped retinal nerve fiber layer defects in experimental glaucoma preliminary report.

Many investigators have reported that abnormalities in the retinal nerve fiber layer may be the earliest sign of primary open-angle glaucoma. We attempted to create defects in the retinal nerve fiber layer in experimentally induced glaucoma and to examine their histology. By repeated circumferential argon laser photocoagulation of the trabecular meshwork of normal cynomolgus monkeys, we succeeded in causing a continuous increase in intraocular pressure (IOP). During the course of this experiment, cupping of the optic nerve head, wedge-shaped retinal nerve fiber layer defects, and halo glaucomatosus developed, all of which are defects that are similar to those seen clinically in primary open-angle glaucoma. The IOP required for this fundus change was 25, 35, and 43 mmHg, indicating great individual variation. Histological examination revealed localized degeneration, loss of axon bundles, and diffuse thinning of the nerve fiber layer in the area of these wedge-shaped defects in the retinal nerve fiber layer. These results may indicate that the optic-nerve-damaging mechanism, both localized and generalized, is the same in the cynomolgus monkey and in man.

Animals↗
PubMed1985

Cholangio-venous reflux as a cause of recurrent hyperamylasemia in choledochal dilatation with anomalous pancreaticobiliary ductal union: an experimental study.

Cylindrical choledochal dilatation, associated with anomalous pancreaticobiliary ductal union, causes recurrent episodes of right hypochondrial pain, vomiting, and fever. The symptoms are very often accompanied by hyperamylasemia, which is generally considered to be due to acute pancreatitis. However, our clinical experience and experimental studies have led us to the conclusion that pancreatitis is not the sole cause of hyperamylasemia. In this paper we report our further investigations of the cause of the hyperamylasemia. In 22 mongrel adult dogs, intracholedochal infusion was performed under a continuous hydrostatic pressure of 20 cm H2O for 2 hours. Solutions of amylase from three different sources and a lipase were used in the range of concentrations found clinically in the bile within a cylindrical choledochal dilatation. In the 3 groups, hyperamylasemia was proven by quantitative estimation of serum amylase level and/or by the changes in specific amylase isozymes. Lipase was also shown to transfer into the blood stream. In an additional experiment on 5 dogs, only the extrahepatic biliary tree, including the gallbladder, was infused with a solution of amylase from Bacillus subtilis. This produced no increase in the serum amylase. Our experiments suggest that amylase passes from the hepatocholedochal system into the blood stream. This phenomenon has long been known as cholangiovenous reflux.

Amylases↗
PubMed1983

Sarcomatous Wilms tumor associated with consumption coagulopathy.

This is a case report of a sarcomatous Wilms tumor complicating disseminated intravascular coagulation with gastrointestinal bleeding, ascites, pleural effusion, and hepatitis after the second course of actinomycin D. A sarcomatous Wilms tumor is believed to have an unfavorable prognosis even if multimodal therapy is given. Arteriovenous fistulae which we created for purposes of chemotherapy and hyperalimentation by microvascular-sleeve anastomosis functioned well for three years in spite of repeated punctures.

Arteriovenous Shunt, Surgical↗
PubMed1983

[Intra-operative irradiation of solid tumors in children].

For the purpose of getting better therapeutic ratio of radiation therapy, an intra-operative irradiation was scheduled and attempted. The advantages of this modality are 1) only the target area is irradiated under the direct vision, 2) unnecessary area is not irradiated due to the selected field and selected electron beam energy, and 3) repeated fractionated irradiation are not necessary and an intensive post-operative chemotherapy can be started earlier. Electron beams of betatron are used according to the necessary depth of tumor volume: usually 8 or 10 MeV are used. The irradiation fields changed by the plastic treatment cones 4 cm to 12 cm in diameter according to the necessary tumor field. One of the biggest problems in an actual attempt of intraoperative irradiation was the determination of a single radiation dose. Actual time-dose relationship of the cured cases of Wilms' tumor and neuroblastoma was investigated by world literature. The single doses for 2 years old patients were calculated from Ellis' formula. They were 9.4-11.8 Gy for Wilms' tumor and 6.5-12.2 Gy for neuroblastoma. Consequently, the single dose was started from 10 Gy and increased up to 15 Gy at the present time. External irradiation was scheduled for supplement if necessary. The details of irradiation on 5 cases were discussed. The clinical evaluation of this treatment method will take time, and many problems remain to be solved clinically and experimentally, such as the radiation effect and side effect of a large single dose.

Adolescent↗
PubMed1983

Immunohistochemical identification of cholinergic cells in non-cloned tumor cells.

The objective of this investigation was to characterize non-cloned neuroblastoma cells immunohistochemically. In this study, the cholinergic cells in three mouse tumors were identified by using a choline acetyltransferase (CAT) antibody. Different cholinergic cell distribution patterns were found in the three tumors by using a fluorescence-activated cell sorter (FACS). An antibody to CAT was prepared by immunization of guinea pigs with CAT-antigen from bovine brain. The specificity of the antibody obtained was examined with mouse cervical spinal cord. Identification of the cholinergic cells was performed in three types of non-cloned tumor culture cells, neuroblastoma C-1300 in A/J mice, glioblastoma 203GL in C57BL6 mice and lymphosarcoma 6C3HED in CBA mice. The CAT content and distribution were determined by radiochemical assay, immunohistochemical staining, and individual cell counting with a FACS. The results of radiochemical assay and immunohistochemical staining were in agreement with the CAT distribution pattern determined by cell counting with FACS IV.

Animals↗
PubMed1982

Experimental analysis of the ill effect of anomalous pancreaticobiliary ductal union.

An ideal canine model of anomalous pancreaticobiliary ductal union, similar to a human anomaly, was devised. Direct anastomosis of the dorsal pancreatic duct and the choledochus was employed (dorsal pancreaticocholedochostomy). The ventral pancreatic duct was not manipulated. Cylindrical choledochal dilatation results in 13 out of 20 adult dogs and in 4 out of 6 puppies. Dilatation of the intrahepatic biliary tree and thickening of the choledochal wall in a hepatic direction were observed in high ratio among adult dogs. Puppies had less dilatation. The activation of pancreatic enzymes was studied in bile containing pancreatic juice. The proteolytic enzymes, trypsin and elastase were proven to be activated in the bile without the presence of enterokinase in the pancreaticocholedochostomy model. This would be the cause of the ill effects of refluxed pancreatic juice into bile in anomalous pancreaticobiliary ductal union.

Amylases↗
PubMed1981

Idiopathic gastric volvulus in infancy and childhood.

Idiopathic gastric volvulus is not rare, especially in the neonate and in infancy. Between 1966 and 1980 we managed 44 cases of gastric volvulus. In 22 of the cases, initial examination was performed under 1 year of age. The main symptoms in this group were vomiting and abdominal distention, while those in the group over 2 years of age were abdominal distention, weight loss, nausea, appetite loss etc. The upper G.I. series were the most important in diagnosis. There was only one case of acute volvulus, which was treated operatively on an emergency basis. Chronic volvulus could be treated conservatively, except in 2 cases. This consisted in the positioning of the patient in the upright right recumbent position after feeding, for at least 1 hour. In the supine position, the gastric fundus is filled and dilated when the milk is poured into the stomach, the fundus is pulled postero-caudally and the antrum is pulled upwards, resulting in the combined type of organo-axial and mesenterico-axial volvulus. Over 2 years of age, 77% required operation. The fixation of the gastric fornix with the diaphragm was performed, using 5 or 6 stitches. The result was quite satisfactory. We recommend this procedure in this operation.

Acute Disease↗