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Biomedical subjects

K Sakamoto

Publications and source records attributed to K Sakamoto.

At least 991 records · Page 55Linked to original sources
PubMed1984

Immunodeficiency as a factor in lymphomagenesis.

The human immune system has evolved multiple cellular and humoral defense mechanisms against the lymphotropic virus, EBV. NK cells, suppressor T-cells, cytotoxic K-cells, memory T-cells, and humoral immune responses usually subdue the virus into latency. Individuals with immune deficiency are at great risk of developing immunoregulatory disturbances and lymphoproliferative diseases when confronted by EBV. The infection of B-cells by EBV provokes a marked activation of immunoregulatory T-cells and requires restoration of immune homeostasis during convalescence. This is accomplished with difficulty in an individual with significant immune defects. The X-linked lymphoproliferative syndrome is an exemplary model for studying EBV in immune deficient individuals. Boys with XLP can develop acquired agammaglobulinemia, aplastic anemia, chronic or fatal IM, and a variety of B-cell malignant lymphomas following infection by the virus. We have identified multiple immune defects in the patients and progressive immunoregulatory disturbances following infection by the virus. Other patients with immune deficiency syndromes, i.e., ataxia telangiectasia or the renal transplant recipient, are also at increased risk for developing EBV-induced lymphoproliferative diseases. Moreover, certain families are at increased risk for EBV-associated malignancies, especially those with a triad of manifestations (i.e., autoimmunity, immunodeficiency, and lymphoma). Chromosomal breakage as seen in patients with ataxia telangiectasia may predispose to leukemogenesis. Immunoregulatory defects are also probably predisposing factors to lymphomagenesis. Both inherited and acquired defects can render persons vulnerable to leukemia and lymphoma.

Burkitt Lymphoma↗
PubMed1984

[Toxicological studies on a new cephamycin, MT-141. V. Its subacute toxicity in beagle dogs].

The 30-day subacute toxicity of MT-141 was studied in adult Beagle dogs with intravenous (i.v.) administrations of 100 to 1,200 mg/kg/day. The obtained results were as follows. MT-141 at the doses lower than 800 mg/kg/day i.v. had no toxicity in male and female Beagle dogs. An increase in water intake was closely related to that in urine excretion after i.v. treatments with 1,200 mg/kg/day of MT-141 in the males and females. MT-141 at the doses higher than 1,000 mg/kg/day i.v. of MT-141 caused slight local irritation at the site of injection in the males and females. In the females, the dose-dependent changes induced by treatments with the doses above 1,000 mg/kg/day i.v. of MT-141 were a significant decrease in the level of serum K and a significant increase in the activity of serum LAP. In the males, this compound produced significant dose-dependent changes in toxicological parameters such as a decrease in the activity of GOT at the doses higher than 1,000 mg/kg/day i.v., a descent in the levels of U-K, U-Cl and OP at the dose of 1,200 mg/kg/day i.v., an elevation in the level of serum alpha 1- and alpha 2-G, and an increase in the volume of excreted urine at the dose of 1,200 mg/kg/day i.v. It is concluded from the above-mentioned results that the maximal "no effective" dose of MT-141 is 800 mg/kg/day i.v. and the toxic dose of MT-141 is above 1,000 mg/kg/day i.v. in male and female Beagle dogs.

Animals↗
PubMed1984

[Clinical effect of cephems: cefoperazone in the treatment of postoperative infections].

Cefoperazone (CPZ) has a broad antibacterial spectrum against Gram-positive, -negative aerobic and anaerobic organisms, it is also highly active against Pseudomonas sp. and Enterobacter sp. which are hardly susceptible to current cephalosporins. The clinical studies on CPZ were performed in postoperative wound infections and abdominal cavity infections, and the following results were obtained. Overall clinical effect: The rates of effectiveness were 100% in postoperative wound infections and 71.4% in abdominal cavity infections. Bacteriological effect: The rates of eradication were 90% in postoperative wound infections and 80% in abdominal cavity infections. Side effects: Any side effects on marked changes in laboratory findings were not observed in any of the cases treated with CPZ. Based on the above results, we considered that CPZ is a highly useful antibiotic for the treatment of postoperative infections.

Adult↗
PubMed1983

Pathology of hepatocellular carcinoma in Japan. 232 Consecutive cases autopsied in ten years.

The pathologic findings of 232 consecutive cases of hepatocellular carcinoma (HCC) autopsied during the past ten years at Kurume, Japan, were analyzed from the point of view of global epidemiology, in relation to clinical feature, and in regard to incidence, age, sex, etiologic factors, size of liver, changes in noncancer parenchyma, gross type of tumor, extrahepatic metastases, intravascular and intraductal growths, cancer cell histology, hepatitis B surface antigen (HBsAg) in hepatocytes and cancer cells, liver cell dysplasia, and frequency and clinicopathologic characteristics of minute HCC. Furthermore, postmortem hepatic arteriography and portography were done in 152 livers for comparison with gross anatomy and celiac angiograms. It was found that: (1) epidemiologically, HCC in Japan is distinct from that in the West that it is frequently encapsulated, livers are generally small because of frequent and advanced cirrhosis and small cancer, minute HCC, is not uncommon at autopsy, cirrhosis most commonly associated is the one with thin stroma and medium size nodules, and micronodular cirrhosis is very rare despite frequent alcohol abuse; (2) HCC is increasing in incidence; (3) HBsAg is frequently found in parenchyma; (4) liver cell dysplasia is indirectly related to HBsAg with no evidence for premalignancy; (5) the lung is the most frequent site of metastasis but peritoneal dissemination is unusual; (6) intraportal tumor growth is very common and the hepatic vein is less frequently affected; (7) growth in the major bile duct is frequently associated with intraportal growth and clinically presents as obstructive jaundice; and (8) tumor is supplied solely by arteries and celiac arteriograms are closely correlated with gross pathologic findings.

Adenoma, Bile Duct↗