[Evaluation of autopsy cases in pancreatic cancer]

The incidence of pancreatic cancer has increased recently. The average age of pancreatic cancer patients in our series was 60.6 years; the male to female ratio was 2.3:1. As for tumor location, the head (45.5%) was the most frequent followed by the body (32.7%) and the tail (20%). Pancreatic cancers were histologically classified as duct carcinoma (88.2%), acinar cell carcinoma (0.9%), islet cell carcinoma (1.8%) and undifferentiated carcinoma (9.1%). In 17 cases (15.5%), diabetes mellitus was an accompanying complication.

Glomerulonephritis associated with liver cirrhosis

The glomerular changes of 50 autopsy cases of liver cirrhosis of different etiologies, such as alcohol abuse, HB virus infection, and nonA-nonB virus infection, were studied by light, immunofluorescence and electron microscopy. The glomerular changes observed were as follows; membranoproliferative glomerulonephritis (MPGN) type 1 (7 cases), mild form or early stage of MPGN type 1 (7 cases), mesangial proliferative glomerulonephritis with subendothelial deposits (13 cases), and mesangial proliferative glomerulonephritis without subendothelial deposits (12 cases). These glomerular changes were frequently accompanied by predominant IgA deposition (78% of the immunofluorescence positive cases). Minimal glomerular changes without electron dense deposits were 11 cases, in which IgA was not present in the glomeruli. Thus, glomerulonephritis associated with liver cirrhosis has revealed a spectrum of glomerular changes from MPGN type 1 to mesangial proliferative glomerulonephritis with a common feature of predominant IgA deposition, despite various etiological factors of liver cirrhosis, such as alcohol abuse, hepatitis B virus infection, and nonA-nonB virus infection. A pathophysiological condition of liver cirrhosis, e.g. reduced phagocytic activity of the reticuloendothelial system of the cirrhotic liver, is thought to be a major factor for development of these glomerular changes. The pathogenesis of IgA predominant glomerulonephritis associated with liver cirrhosis may be concerned in the pathogenesis of IgA nephropathy, which still remains to be clarified.

Epithelioid sarcoma. Enzyme histochemical and ultrastructural study

A case of epithelioid sarcoma was studied by electron microscopy and by light and electron microscopic enzyme histochemistry comparing with several control soft tissues. In addition to previously reported ultrastructural features, such as abundant 10 nm cytoplasmic filaments, desmosome-like cell junctions and small cystic spaces surrounded by filopodia or microvilli of the tumor cells, we encountered 10 nm cytoplasmic filaments showing electron dense condensation with a concentrically oriented or whorled pattern and a finger-print-like arrangement and 5'-nucleotidase activity of tumor cell membrane. Among the control soft tissues, 5'-nucleotidase activity was found only in synovial and endothelial cells. Both tumor and synovial cells showed no activity of adenosine triphosphatase, while marked activity of the enzyme was found in endothelial cells. These results support the concept that epithelioid sarcoma is derived from mesenchymal cells undergoing differentiation toward synovial cells during neoplastic transformation.

Possible mechanisms of 15-hydroperoxyarachidonic acid-induced contraction of the canine basilar artery in vitro

Pharmacological studies of the contraction induced by 15-hydroperoxyarachidonic acid (15-HPAA) were done in the isolated canine basilar artery. The maximal contractile force produced by 15-HPAA was 1.5 times that of serotonin and was equivalent to that of prostaglandin (PG) F2 alpha or PGA1. At concentrations in which reductions of [14C]-6-keto-PGF1 alpha (the breakdown product of PGI2) occurred, both 15-HPAA and tranylcypromine contracted the artery, whereas indomethacin consistently relaxed it. In the case of indomethacin, as the drug inhibited the synthesis of [14C]-PGE2, F2 alpha and thromboxane(TX) B2 (the breakdown product of TXA2) as well, it has been considered that the balances between PGI2 and other vasoconstrictive PGs or TX may regulate the tone of the artery. Furthermore, it was shown that 15-HPAA enhanced the synthesis of lipoxygenase products from [14C]arachidonic acid. Experiments were done, therefore, to know whether these enhanced lipoxygenase products participated in the manifestation of contraction induced by 15-HPAA or not. As a result, although indomethacin did not affect the contraction, significant reductions of the contraction were shown by eicosatetraynoic acid. These results suggest that enhanced synthesis of lipoxygenase products may be involved in eliciting contractile responses of 15-HPAA.

Carcinogenicity of benzyl chloride, benzal chloride, benzotrichloride and benzoyl chloride in mice by skin application

The carcinogenicity of benzyl chloride (BYC), benzal chloride (BAC), benzotrichloride (BTC) and benzoyl chloride (BOC), which were suspected as causative agents of lung cancer and maxillary malignant lymphoma of workers employed in factories producing BOC, was examined by skin applications in female ICR mice. After rather high dose exposure, BTC exhibited leukemogenic and pulmonary tumorigenic activities as well as potent dermal carcinogenic activity. After administration of the chemicals at the dose of 2.3 microliter/animal, twice a week for 50 weeks, BTC induced 68% incidence of skin cancers and 58% incidence of pulmonary tumors (including 10% of lung carcinomas) within 399 days. Incidence of skin cancers was 58% for BAC, 15% for BYC and 10% for BOC within 560 days. Considering the extent of possible exposure of the workers to these chemicals in the working environment and the carcinogenic potency of the chemicals tested, it can be concluded that BTC was very probably responsible for causing the cancers seen int he workers employed in manufacturing BOC.

Regulation of liver phosphorylase phosphatase by glutathione disulfide

The mechanism of inactivation of rabbit liver phosphorylase phosphatase by glutathione disulfide (GSSG) was investigated. The catalytic subunit of phosphorylase phosphatase was inactivated by GSSG and other disulfides. Inactivation by GSSG was a concentration-dependent process and resulted in the formation of an inactive, stable enzyme species. The inactivated enzyme could be reactivated by addition of various sulfhydryl compounds, including glutathione (GSH). Homogeneous phosphorylase phosphatase contains, per mol of catalytic subunit (Mr = 33,000), two sulfhydryl groups, one of which reacted with GSSG to form inactive enzyme. Binding studies with [glycine-2-3H]GSSG revealed simultaneous incorporation of 3H radioactivity into the catalytic subunit and stoichiometric loss of catalytic activity. Treatment of the 3H-labeled enzyme with GSH was accompanied by release of 3H radioactivity from the enzyme and restoration of enzyme activity. The results suggest that inactivation of phosphorylase phosphatase by GSSG results from the formation of a mixed disulfide between GSSG and one of the two sulfhydryl groups in the catalytic subunit.

Analysis of the contractile responses of the ileal segment of the isolated blood-perfused small intestine of rats to adenosine triphosphate and related compounds

For close-arterial injection the isolated small intestine of the rat was perfused by a cross-circulation technique at a fixed flow rate through the superior mesenteric artery with arterial blood from a donor. Single intra-arterial injections of purine derivatives elicited a monophasic fast contraction of the ileum. In order to elucidate the mechanism of the fast contraction, adenosine triphosphate (ATP) was chosen for further investigations. The ileal response to ATP was abolished by tetrodotoxin, hexamethonium or morphine, but was resistant to blockade by atropine, methysergide or mepyramine. These results definitely indicate that ATP causes the fast contraction of the ileum by a stimulation of neuronal elements in the myenteric plexus involving cholinergic interneurons.

Femoral vascular responses to purine and pyrimidine derivatives: release of 5-hydroxytryptamine by purine derivatives in isolated, cross-circulated rat hindlimb

The mode of actions of the purines, adenosine, adenosine-5'-triphosphate (ATP), guanosine and guanosine-5'-triphosphate (GTP), and the pyrimidines, cytidine, cytidine-5'-triphosphate (CTP), thymidine, thymidine-5'-triphosphate (TTP), uridine and uridine-5'-triphosphate (UTP) was investigated in the isolated hindlimb preparation of the rat. A single injection of adenosine, ATP, GTP or UTP into the femoral artery induced a biphasic response, a prominent vasoconstriction preceded by a transient vasodilatation, whereas guanosine and uridine caused only a vasoconstriction. Cytidine, CTP, thymidine and TTP were almost ineffective on the vascular bed. The vasoconstrictor responses to adenosine, ATP, guanosine and GTP were effectively antagonized by either methysergide or reserpine, whereas those to uridine and UTP were not modified by either methysergide or phentolamine. Adenine, D-(-)-ribose and hypoxanthine had no effect on the vascular bed. The 5-hydroxytryptamine (5-HT) release from the hindlimb was fluorometrically determined. The present results provide direct evidence that the vasoconstriction caused by ATP, adenosine, GTP and guanosine is attributed to the release of 5-HT from their stores and that purine nucleotides and nucleosides are capable of releasing 5-HT.

Further studies on the electrophoretic pattern of albumin in diabetic sera

Human sera from normal subjects and diabetic patients were electrophoresed in an urea-containing gel; polyacrylamide gel and cellulose acetate membrane. In polyacrylamide gel, normal serum exhibited the fast migrating Band 2 and the slower migrating albumin Bands 4 and 5 after overnight fasting and also after glucose administration. In diabetic serum Bands 4 and 5 did not appear before or after glucose administration in low mercaptoethanol gel which abnormality resembled the pattern in C57BL/KsJ-db/db mice. In high mercaptoethanol gel, about half of the diabetic sera exhibit a delay in appearance of Bands 4 and 5, i.e., Bands 4 and 5 were not observed 30--60 min after glucose administration, which seems to resemble the pattern in C57BL/6J-ob/ob mice. Conditions of electrophoresis in urea-submerged cellulose acetate membrane (species of buffer systems, pH, ion concentration, mercaptoethanol, ethylene-diaminetetraacetic acid, Ca2+ ion, urea concentration, etc.) were observed in relation to albumin sub-separation. At pH 8.6 with barbital buffer, albumin separated into two bands, and at pH 10.6 with glycine buffer, albumin separated into four bands. Almost all diabetic sera (ca. 80%) exhibited different electrophoretic patterns from that of normal serum.