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Biomedical subjects

Y Shirai

Publications and source records attributed to Y Shirai.

At least 271 records · Page 15Linked to original sources
PubMed1979

A morphological study in germfree mice (Salmonella infection).

The morphological manifestation of the intestinal infections of Salmonella typhimurium by the intestine rolled method in both conventional DKI and germfree mice have been investigated in our laboratory. In the conventional mice, the morphological manifestation of intestinal infection shows no difference from the general features of infection, while in the germfree mice, the manifestation is characterized by the so-called non-reactive necrotizing enteritis without cellular reaction. When infection in the germfree mice occurs, some state of immunological insufficiency should be taken into consideration. In infections of germfree mice it is difficult to consider the immunological or the allergic reaction which is expected in the conventional mice. In addition, the direct influences of bacteria such as endotoxin must be taken into consideration as another possibility, but the very limited localized lesions, as seen in this experiment cannot always be suggested to be due to the direct influence of bacteria or intoxication. Though there are many problems to be solved in the future, we are now able to state a kind of mechanism similar to that of Shwartzman's phenomenon cannot be ignored in the infection in newborns or in immunologically immature animals.

Animals↗
PubMedDate not supplied

Carcinoma of the ampulla of Vater: histopathologic analysis of tumor spread in Whipple pancreatoduodenectomy specimens.

Controversies exist regarding the application of the pylorus-preserving pancreatoduodenectomy (PPPD) to malignancies. This study was intended to disclose the pattern of spread of ampullary cancer and to substantiate that tumor spread at resectable stages does not involve the tissues preserved by PPPD. We examined 40 consecutive Whipple pancreatoduodenectomy specimens: mucosal cancer, 4 cases; cancer invading (but not penetrating) the sphincter of Oddi, 1; cancer invading the submucosa of the duodenum, 12; cancer invading the proper muscle of the duodenum, 5; cancer invading the subserosal layer of the duodenum, 7; and cancer invading pancreatic parenchyma, 11. Five cases of mucosal cancer or cancer invading (but not penetrating) the sphincter spread locally without nodal involvement and showed a 5-year survival of 80% without recurrence, being better (p < 0.05) than the 40% survival for patients with more advanced cancers. Sixty-three percent of the remaining 35 cases had metastasis to regional lymph nodes. The 5-year survival of 28% among those with cancer penetrating the proper muscle was worse (p < 0.05) than the 59% survival for those with less advanced cancers. No cases had involved the anatomic structures that would have been preserved by a PPPD. In three cases (7.5%), gastric cancer coexisted. In conclusion, ampullary cancer not penetrating the sphincter spreads locally. Once penetrating the sphincter, it often spreads regionally and causes recurrence. Cancer penetrating the proper muscle of the duodenum bears a worse prognosis. PPPD is an attractive alternative to the Whipple operation for ampullary cancer because no involvement was found in the tissue preserved by the PPPD. However, surgeons should be aware of a concomitant gastric cancer when doing a PPPD.

Adult↗
PubMedDate not supplied

Serum and urinary boron levels in rats after single administration of sodium tetraborate.

The pharmacokinetics of boron was studied in rats by administering a 1 ml oral dose of sodium tetraborate solution to several groups of rats (n=20) at eleven different dose levels ranging from 0 to 0.4 mg/100 g body weight as boron. Twenty-four-hour urine samples were collected after boron administration. After 24 h the average urinary recovery rate for this element was 99.6+/-7.9. The relationship between boron dose and excretion was linear (r=0.999) with a regression coefficient of 0.954. This result suggests that the oral bioavailability (F) of boron was complete. Another group of rats (n=10) was given a single oral injection of 2 ml of sodium tetraborate solution containing 0.4 mg of boron/100 g body wt. The serum decay of boron was followed and found to be monophasic. The data were interpreted according to a one-compartment open model. The appropriate pharmacokinetic parameters were estimated as follows: absorption half-life, t1/2a=0.608+/-0.432 h; elimination half-life, t1/2=4.64+/-1.19 h; volume of distribution, Vd = 142.0+/-30.2 ml/100 g body wt.; total clearance, Ctot=0.359+/-0.0285 ml/min per 100 g body wt. The maximum boron concentration in serum after administration (Cmax) was 2.13+/-0.270 mg/l, and the time needed to reach this maximum concentration (Tmax) was 1.76+/-0.887 h. Our results suggest that orally administered boric acid is rapidly and completely absorbed from the gastrointestinal tract into the blood stream. Boric acid in the intravascular space does not have a strong affinity to serum proteins, and rapidly diffuses to the extravascular space in proportion to blood flow without massive accumulation or binding in tissues. The main route of boron excretion from the body is via glomerular filtration. It may be inferred that there is partial tubular resorption at low plasma levels. The animal model is proposed as a useful tool to approach the problem of environmental or industrial exposure to boron or in cases of accidental acute boron intoxication.

Animals↗
PubMedDate not supplied

Spread of gallbladder carcinoma: CT evaluation with pathologic correlation.

BACKGROUND: To assess the accuracy of computed tomographic (CT) imaging in the detection of spread and staging of gallbladder carcinoma. METHODS: CT findings of spread of gallbladder carcinoma in 59 Japanese patients who underwent radical surgery were correlated retrospectively with pathologic findings. RESULTS: The incidence of histologically proven nodal involvement was 54% (32 patients) and the most common spread of gallbladder carcinoma. The sensitivities in CT detection of N1 and N2 nodal involvement were 36% and 47%, respectively; positive predictive values were 94% and 92%, respectively. Direct extension to the liver, extrahepatic bile duct, and gastrointestinal tract or pancreas were histologically confirmed in 24, 18, and five patients. The sensitivities in the CT detection of direct spread to the liver of less than 2 cm, more than 2 cm, the extrahepatic bile duct, and the gastrointestinal tract or pancreas were 65%, 100%, 50%, and 57%, respectively; positive predictive values were 77%, 100%, 90%, and 100%, respectively. The incidence of liver metastases and involvement of interaortocaval nodes were 7% and 16%, respectively. The sensitivities in CT detection of liver metastases and involvement of interaortocaval nodes were 75% and 21%, respectively; positive predictive values were 100% and 86%, respectively. CT could not detect direct spread to omentum and peritoneal seedings. CONCLUSION: For detecting the spread of gallbladder carcinoma, CT imaging has low to moderate sensitivity; however, CT imaging can help in determining resectability and in planning the treatment, especially in advanced-stage gallbladder carcinoma, because of a high positive predictive value.

Adult↗
PubMedDate not supplied

Sensory nerve supply in the human subacromial bursa.

The subacromial bursa is the major component of the subacromial gliding mechanism. The neural elements of the subacromial bursa obtained from specimens that underwent autopsy and surgery were investigated by the silver impregnation and immunohistochemical methods with antisera to substance P and calcitonin gene-related peptide; which are considered to be involved in nociceptive transmission, and protein gene product 9.5. Free nerve endings, Ruffini endings, Pacinian corpuscles, and two kinds of unclassified nerve endings were observed. Most of these receptors were observed of the roof side of the coracoacromial arch, which is exposed to stress because of the impingement. A delta and C fibers, thought to be nerve fibers of free nerve endings, were immunoreactive to substance P and calcitonin gene-related peptide. On the other hand, thick fibers thought to originate in encapsulated mechanoreceptors were not immunoreactive to substance P. The subacromial bursa receives nociceptive stimuli and proprioception and seems to regulate appropriate shoulder movement.

Adult↗