Characteristics of acetone cluster ion beam for surface processing and modification.

An acetone cluster ion beam was produced by the adiabatic expansion method without using helium as a support gas. The cluster source for the production of ethanol clusters was replaced with that sealed with metal gaskets. The Laval nozzle for the production of ethanol clusters was also replaced with a stainless steel conical nozzle. The cluster size distributions of the acetone cluster ion beams had mean values approximately at 2 × 10(3) molecules and increased with source pressure. The typical beam current density of the acetone cluster ion beam was approximately 0.5 µA/cm(2).

A prospective randomized trial of the preventive effect of pre-operative transcatheter arterial embolization against recurrence of hepatocellular carcinoma.

To clarify whether pre-operative transcatheter arterial embolization (TAE) improves survival after hepatectomy, a prospective randomized comparative study was done. Of a total of 115 registered patients having solitary hepatocellular carcinoma (HCC) 2 to 5 cm in diameter, 18 (15.7%) were excluded after randomization. As a result, 97 patients were chosen as subjects and divided into two groups: hepatectomy with (group A: n=50) and without (group B: n=47) pre-operative TAE. The period of observation of the patients who survived the surgery was between 4.0 and 6.6 years. The randomization appeared to have provided well-balanced groups of patients and the clinico-pathological characteristics of the two groups were quite similar. The necrotic part of the cancerous lesions, as confirmed by operative specimens, amounted to 74.8+/-33.4% (mean +/-SD) in group A and 6.8+/-7.2% in group B (P<0.01). However, the cancer-free survival rates after hepatectomy in both groups showed little difference (39.1+/-7.0 (%+/-SE) and 31.1+/-0.1, respectively). We speculate that TAE is not effective against such HCC accessory lesions as minute intrahepatic metastasis and tumor thrombus and that pre-operative TAE does not improve post-operative survival.

[Studies on titanium casting. (1) Influence of the mold temperature on titanium castings].

Pure titanium and titanium alloys have excellent biocompatibility, excellent corrosion tarnish resistance, a quarter of the specific gravity of gold base alloys and suitable mechanical properties for dental clinical use. However, titanium has some undesirable characteristics. For example, it has a high melting temperature and chemical reactivity at high temperatures. The investigate influence of the mold temperature on castability and mechanical properties of the titanium castings was study. The castability was found to be good at various mold temperatures, but the higher the mold temperature during casting, the greater the adhesive phenomenon between titanium surface and the investment. From the EPMA observation of the surface layer on the titanium castings, an Si- rich layer whose thickness increased considerably with increasing temperature was observed. The Vickers hardness in the surface layer was greater than that in the inner part. At a higher mold temperature during casting the thickness of the high Vickers hardness layer was increased. There was a relationship between the Vickers hardness value and the thickness of Si rich layer. In the tensile strength test of titanium castings, elongation values decrease and tensile strength values increased with the rise in mold temperature.

[2 surgically treated cases of adrenocortical carcinoma producing steroid hormones without endocrinological symptoms--case report and a review of cases in the Japanese literature].

We have experienced two male cases of an adrenocortical carcinoma that have produced steroid hormones without endocrinological symptoms. Both men were admitted to hospital because of an abdominal pain and left hypochondral tumors. In each case, an abdominal CT, an ultrasonogram and an angiogram demonstrated a left adrenal tumor, and levels of blood dehydroepiandrosterone sulfate, etiocholanolone, pregnenolone sulfate and urine 17 KS were elevated. The tumors were resected and the histology revealed that they were adrenocortical carcinomas. Postoperatively, the levels of their urine hormones returned to normal values, though in one man recurrence occurred a year later. Only 8 cases of an adrenocortical carcinoma that has produced steroids without specific endocrinological symptoms have been reported in Japan, and we also report on two cases herein.

[A case of primary adenosquamous carcinoma of the stomach preoperatively diagnosed by endoscopic biopsy].

A 53-year-old complained of upper abdominal pain. A diagnosis of Borrmann III type gastric cancer in the posterior part of the corpus region was made by X-ray and endoscopy, and primary adenosquamous carcinoma was preoperatively diagnosed by endoscopic biopsy. Subtotal gastrectomy was performed. The part of the adenocarcinoma adjacent to squamous-cell carcinoma was poorly differentiated. Adenosquamous carcinoma of the stomach is rare. Furthermore, preoperative diagnosis by endoscopic biopsy is extremely unusual, having been reported in 7 cases in Japan including ours. And in 5 cases out of 6, region of the adenocarcinoma was the poorly differentiated type.

Assessment of enterohepatic circulation of 3H-digoxin with a minimal interruption technique.

The biliary excretion of 3H-digoxin in rats prepared for bile sampling with minimal interruption of the enterohepatic circulation was compared with that in rats with complete interruption after intraduodenal or intravenous administration. Following dosage by either route, significantly more radioactivity was recovered from animals with nearly intact enterohepatic circulation. The method described allows direct measurement of this cycle in unanesthetized animals without the consequences of bile depletion.

Studies on immunoreactive gastrin with special regard to its molecular form and G cell counts in gastrointestinal mucosa of fetal, neonatal and adult rats.

Changes of distribution of immunoreactive gastrin (IRG) and molecular forms of intra-tissue gastrin in the growth course of rats were examined. The results obtained were as follows; 1) IRG concentrations and G cell counts were extremely low in the fetal antral mucosa. However, a gradual increase of the above was observed during the neonatal suckling period, accompanied by a rapid increase at the commencement of feeding. 2) IRG concentrations in the duodenal mucosa of the fetal and neonatal period were markedly higher than that of adult rat. 3) Jejunal IRG concentration was negligible in the fetal period. The value obtained from the postnatal rats was equal to or higher than that of adult rat. 4) The major form of antral gastrin was G-17 throughout the fetal and adult age. No qualitative change of antral IRG in the growth course of rats was seen. 5) The major form of the duodeno-jejunal mucosa was G-17 in the fetal period and thereafter G-34 increased gradually in the growth course of rats. These results suggested that, (1) suckling and feeding appeared to be a trigger of the production and release of antral gastrin in the growth course of rats. (2) In the initial stage of the growth, G cells distributed in the duodeno-jejunal mucosa as well as in the antral mucosa may participated in the production and release mechanism of gastrin.

Studies on exogenous and endogenous interaction of gastrin and secretin in a case of achalasia.

Studies were carried out in a case of achalasia. Administration of secretin caused relaxation of the spastic condition of LES, and high levels of serum gastrin and lower levels of plasma secretin are suggested to be related with the abnormally spastic condition of LES in the patient.

Serum gastrin and gastrin-like immunoreactivity of gastrointestinal mucosa in fetal, neonatal and adult rats.

Serum gastrin concentration became became detectable in rats at one week after birth (56 pg/ml), and a rapid rise to 198 pg/ml was seen at two weeks after birth. Gradual decreases were seen again at three weeks and four weeks, and thereafter it attained the adult level of 132 +/- 17.6 pg/ml. In regards to the gastrin-like immunoreactivity (GLI) in the gastrointestinal mucosa during the fetal period, the values were extremely low even in the antral mucosa. However, the GLI showed an increase during the neonatal suckling period, and was accompanied by a remarkable increase at the commencement of feeding. This GLI coincided with so-called little gastrin, and while an increase accompanied by the development of growth was seen, no qualitative changes were evident. GLI values were high in the duodenal mucosa followed by the antrum, and positive evidence was also seen in the corpus of the stomach and jejunum. High values of GLI in the mucosae were gradually seen at two weeks after birth coinciding with the rise in serum gastrin levels, and the significance of the increases was discussed from the anlge of the trophic effect of gastrin.