Co-carcinogenic effect of chrysotile and amosite asbestos with benzo(a)pyrene in the lung of hamsters

To clarify co-carcinogenic effects of chrysotile (Chry) and amosite (Amo) asbestos with benzo(a)pyrene (Bap), 0.2 mg UICC (International Union against Cancer) standard reference sample of asbestos and 0.4 mg Bap were applied intratracheally once a week for 6 weeks. Eighteen and 24 months after the last instillation the number of tumors was examined. The Chry + Bap group yielded 37 tumors including 16 carcinomas in 12 animals, and the Amo + Bap group yielded 30 tumors including 11 carcinomas in 12 animals. Tumor-bearing animals were 100% in the Chry + Bap group and 92% in the Amo + Bap group, and carcinoma-bearing animals were 83% and 67%, respectively. The animals injected with Chry, Amo, and Bap alone developed no tumors. The number of tumors and carcinomas and the frequency of the tumor- or carcinoma-bearing animals in Chry + Bap and Amo + Bap were significantly higher than those of the groups injected independently. The number of tumors or the frequency of tumor-bearing animals was higher in Chry + Bap than in Amo + Bap; however, these differences were not significant. These results indicate that both Chry and Amo play an important role in the genesis of bronchogenic carcinoma.

Production and secretion of endothelin by hepatocellular carcinoma

To clarify whether hepatocellular carcinoma (HCC) may produce and secrete endothelin (ET), we measured plasma levels of ET-1 and big ET-1, a precursor form of ET-1, in 30 patients with HCC. When compared to normal subjects, a substantial number of patients had elevated plasma ET-1 and big ET-1 levels, determined by specific enzyme immunoassays. The mean (+/- SD) plasma concentrations of ET-1 (1.7 +/- 0.9 pmol/L) and big ET-1 (6.1 +/- 4.8 pmol/L) in patients' group were significantly (P < 0.01) higher than those (1.0 +/- 0.3 and 2.0 +/- 0.8 pmol/L, respectively) in control group. There was a significant positive correlation between plasma big ET-1 and alpha-fetoprotein (r = 0.77, P < 0.01). Some of the 29 patients with liver cirrhosis also had modestly elevated plasma big ET-1 levels. The mean (+/- SD) plasma big ET-1 concentration (3.1 +/- 0.9 pmol/L) in patients with liver cirrhosis was significantly (P < 0.01) higher than that in control group, although there was no significant difference between the mean plasma ET-1 levels of both groups. Raised plasma big ET-1 and, less markedly, ET-1 levels in patients with HCC decreased after successful transcatheter arterial embolization concomitantly with a reduction in tumor sizes and a decrease in plasma alpha-fetoprotein levels. In six patients, an arteriovenous difference in ET-1 and big ET-1 levels across the tumor bed with a higher concentration in the venous circulation was found. Reverse-phase high performance liquid chromatography revealed that major portions of immunoreactive ET-1 and big ET-1 in hepatic venous plasma coeluted with synthetic ET-1 and big ET-1, respectively. Immunohistochemistry of HCC tissues from two patients demonstrated HCC cells positive for ET-1 and big ET-1, whereas no ET immunoreactivity was found in adjacent nontumorous hepatocytes. We conclude from these results that ET is produced by and released from a substantial number of HCC, which may stimulate proliferation of carcinoma cells as an autocrine or paracrine growth factor.

Mechanism of the lipid-lowering effect of ethyl all-cis-5,8,11,14,17-icosapentaenoate

The effect of highly purified ethyl all-cis-5,8,11,14,17-icosapentaenoate (EPA-E) on cholesterol metabolism in rats was examined to clarify the mechanism of its hypolipidemic action. Pretreatment with EPA-E reduced the increase in plasma radioactivity after oral administration of [14C]cholesterol. The conversion of [14C]3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) to [14C]mevalonic acid was significantly inhibited in liver microsomes obtained from rats treated with EPA-E. There was an increase in free cholesterol and a marked rise in the eicosapentaenoic acid (EPA) content of phospholipids in these microsomes. EPA-E restored the suppression of biliary secretion induced by feeding a casein-rich diet to bile duct-cannulated rats. Furthermore, when serum lipoprotein (d < 1.210) from rats given EPA-E was i.v. injected into normal rats, a more rapid elimination of cholesterol was observed as compared to that in rats injected with lipoprotein from EPA-E-untreated rats. This rapid clearance was found in the lipoprotein fractions of d < 1.006 and 1.006 < d < 1.063. These findings suggest that EPA-E has an inhibitory effect on intestinal cholesterol absorption and hepatic cholesterol biosynthesis, and an enhancing effect on hepatic biliary secretion. EPA-E would also seem to cause modification of serum lipoproteins, whereby their clearance from the serum is increased.

Spontaneous remission in Cushing's disease

Two patients with Cushing's disease underwent spontaneous clinical and biochemical remission following a period of secondary adrenal insufficiency. One of the patients was untreated, while the other had been treated with partial bilateral adrenalectomy before. Both patients underwent remission shortly after the administration of dexamethasone for diagnostic purposes and remained symptom free for 2 and 3 years, respectively, which was followed by relapse of the disease. We conclude that although resolution of Cushing's disease may occur spontaneously, probably by hemorrhagic infarction of corticotroph microadenomas, careful follow-up studies are required since the relapse of the disease occurs later in some patients.

[Analytical validation in compendium methods]

Well validated analytical methods should be used in official tests in order to eliminate the type I and II errors. The analytical validation is the process to confirm that the performance characteristics of a proposed analytical method is adequate for its intended use. The performance characteristics of an analytical method are validated by evaluating that observed analytical performance parameters of the analytical method meet the criteria required by a test to which the analytical method is applied. Basic rules in analytical validation were described in this report. The more strict rules for determination of the limit of detection and the test of precision than usually applied were proposed.

Comparative study on E6 and E7 genes of some cutaneous and genital papillomaviruses of human origin for their ability to transform 3Y1 cells

E6 (or E7) genes of some genital and cutaneous human papillomaviruses (HPVs) were compared for their ability to transform cells of a rat fibroblastic line (3Y1) by using recombinant retroviruses. The E6 gene of genital cancer-associated HPV 16 or 18 was found to induce a characteristic morphological change, i.e., densely packed arrays of elongated cells forming swirl patterns. This change is the same as that induced by the E6 gene of cutaneous cancer-associated HPV 5, 8, or 47, which we described previously. The E6 gene of HPV 1 or 11, associated with benign tumor of cutaneous or genital tissue, respectively, induced no such change. The E6 genes of all these cutaneous and genital HPVs enhanced anchorage-independent growth of the target cells induced by E7 gene of HPV 16 or 18, and this enhancing activity of HPVs 16, 18, and 47 was stronger than that of HPVs 1 and 11. A distinct type of morphological transformation of 3Y1 cells, i.e., rounded miniaturized cells that were densely packed without forming any distinctive arrays, was found to be induced strongly by E7 genes of HPVs 16 and 18, weakly by E7 of HPVs 1 and 11, and not at all by E7 of HPV 47. The results suggest that the intensity of the morphological change induced by E6 genes, rather than E7 genes, is correlated to the risk of malignant conversion of the lesion with which the corresponding HPVs are associated.

The producer and biological activities of SO-75R1, a new mutactimycin group antibiotic [corrected]

The producer of SO-75R1, a new anthracycline group antibiotic was identified as Nocardia brasiliensis. SO-75R1 was active against Gram-positive bacteria, but not active against Gram-negative bacteria or fungi. All tested Nocardia brasiliensis strains as well as the producer itself were resistant to SO-75R1, although four other pathogenic Nocardia, i.e. N. asteroides, N. nova, N. farcinica and N. otitidiscaviarum were sensitive [corrected].

[A case report of an acute promyelocytic leukemia patient showing remarkable thrombopoiesis prior to granulopoiesis by hM-CSF treatment after chemotherapy]

We report a case of an acute promyelocytic leukemia patient who showed remarkable thrombopoiesis prior to granulopoiesis by human macrophage colony-stimulating factor (hM-CSF) treatment after chemotherapy. A 50 year-old man was diagnosed as acute promyelocytic leukemia (FAB classification: M3) with t(15;17). He received two courses of induction therapy with daunorubicin and cytarabine followed by consolidation therapy with cytarabine and mitoxantrone. After each course of chemotherapy. hM-CSF (8 x 10(6) units, daily) was given for 14 days. After each treatment with hM-CSF, the increase in number of platelets preceded increase of granulocytes and reticulocytes. When serum levels of granulocyte-macrophage-colony stimulating factor (GM-CSF), granulocyte-colony simulating factor (G-CSF), interleukins-3 (IL-3) and -6 (IL-6) were measured, only that of G-CSF was increased after hM-CSF treatment.

FK506-induced kidney tubular cell injury

Some renal changes associated with cyclosporine, such as tubular vacuolization and glomerular thrombosis, have also been reported with FK506. Furthermore, FK506 therapy is associated with a decrease in glomerular filtration rate and renal plasma flow and an increase in renal vascular resistance. We studied the in vitro tubular cell sensitivity to FK506 in comparison with CsA, the ultrastructural changes induced by FK506 and CsA, and the effect of both drugs on tubular cell growth in vitro. We also investigated whether FK506 and CsA induced endothelin-1 (ET-1) secretion of cultured tubular cells and whether this stimulatory effect coincided with a change in the endothelin systemic synthesis. Exposure of tubular cells to high concentrations of FK506 or CsA (10, 50, 100 microM) induced a time- and dose-dependent cell injury in vitro. The damage induced by FK506 and CsA was characterized by a direct cytotoxic effect on tubular cells, as expressed by release of 3H thymidine from prelabeled cells, N-acetyl-beta-D-glucosaminidase release, and cell detachment. Ultrastructural changes (vacuolizations, swelling, and mitochondrial enlargement) and inhibition of the growth of cultured tubular cells were also observed at high concentrations of FK506 and CsA. Low concentrations of FK506 and CsA (1, 0.1, 0.01, 0.001 microM) were not cytotoxic and induced only a minimal inhibitory effect on the growth of tubular cells in vitro. We demonstrated that FK506 (1, 0.1, 0.01 microM) time-dependently stimulated the secretion of endothelin by cultured tubular cells. CsA 10, 1, 0.1, 0.01 also exerted an enhancing effect on ET-1 secretion in cultured tubular cells. We observed that the concentration of CsA that induced the most important enhancing effect was 10 or 100 times higher than that required for FK506 to observe the same effect. The concentrations of FK506 or CsA that induced ET-1 secretion were not cytolytic for tubular cells in vitro. FK506- or CsA-treated rats showed an increase in serum level of ET-1 in comparison with the control. Through the stimulatory effect on endothelin secretion by tubular cells, FK506 and CsA may induce a perturbation of renal hemodynamics. Concentrations of FK506 and CsA, higher than established serum levels but close to those reached in tissues, are cytotoxic for tubular cells and induced ultrastructural changes and a significant delayed regeneration.

[A case of mediastinal seminoma which penetrated pericardium and invaded left upper lobe]

A 35-year-old man admitted at our hospital, with a complaint of anterior chest pain. Chest x-ray film and CT showed an anterior mediastinal tumor. An invasive thymoma was suspected by the biopsy specimen, invading left upper lobe of the lung. Resections of the tumor, thymus, invasion to the part of the left upper lobe and the pericardium were performed. The pathology showed pure seminoma penetrating the pericardium. As testis and the retroperitoneum were normal, the tumor was diagnosed as mediastinal origin. Adjuvant chemotherapy (CDDP, BLM and etoposide) and irradiation were performed. The patient is alive and well for 7 months postoperatively.

Electron microscopic study of hepatitis B virus-associated antigens on the infected liver cell membrane in relation to analysis of immune target antigens in chronic hepatitis B

To clarify the characteristics of cell surface Pre-S2 Ag, HBcAg and HBeAg immunohistochemically and to explore their relationship with a cellular immune target antigen, 31 liver biopsy specimens from chronic HBV carriers were examined by immunoperoxidase staining. By immune light microscopy, Pre-S2 Ag was detected on the liver cell membrane in 18 (58%) of the 31 cases, HBcAg in 4 cases (13%) and HBeAg in 4 cases (13%). Pre-S2 Ag frequently showed a honeycomb-like membrane expression pattern which was present regardless of liver inflammation, whereas HBcAg and HBeAg exhibited a scattered membrane expression pattern detected in areas of marked inflammation. Of the 18 cases showing a honeycomb-like Pre-S2 Ag expression, 3 concomitantly showed a scattered membrane expression pattern. Immunoelectron microscopy revealed these two distinct membrane expression patterns. In areas showing a honeycomb-like membrane expression pattern, Pre-S2 Ag was demonstrated in the intercellular space and on the basolateral membranes of hepatocytes, but was not detected on the cell membranes in areas of the intercellular space lacking an immunoreaction. Cytoplasmic expression of Pre-S2 Ag was less extensive in these hepatocytes. These findings suggest that the honeycomb-like membrane expression of Pre-S2 Ag results from attachment of extracellular antigen to the liver cell membrane. In contrast, in areas showing a scattered membrane expression pattern, Pre-S2 Ag, HBcAg and HBeAg were each detected as single-layered linear deposits along the cell membrane, but were absent in the intercellular space. Each antigen was also expressed abundantly in the cytoplasm, and the immunoproducts appeared to fuse with the cell membrane. These findings suggest that the scattered membrane expression of these antigens results from intrahepatic transfer of antigen synthesized in the liver cell to the cell membrane, possibly serving as a target for the host immune-mediated response in connection with inflammation.

Contrasting effects of interferon-gamma and interleukin-4 on neopterin generation from human adherent monocytes

The production of neopterin is closely correlated with activation of cell-mediated immunity. Neopterin appears to be produced by human macrophages specifically stimulated with interferon-gamma (IFN-gamma). Interleukin-4 (IL-4), a B and T stimulatory factor, has recently been shown to inhibit monocyte/macrophage functions, including the ability to suppress monocyte-generated cytokines. In this report we confirmed previous studies that identified the monocyte/macrophage as the main producing cell among human blood cells and that secretion is stimulated by IFN-gamma and lipopolysaccharides (LPS). IL-4 inhibits the generation of neopterin from unstimulated monocytes. This inhibitory effect was dose dependent and occurred at concentrations lower than 0.01 ng/ml. However, IL-4 had only a minimal inhibitory effect on LPS-induced generation of neopterin and could not reverse IFN-gamma-induced neopterin secretion from adherent monocytes. Furthermore, we report that LPS induced IFN-gamma production in monocyte culture. This production is strongly inhibited by IL-4 treatment. These findings indicate that IL-4 can regulate the synthesis of neopterin by adherent blood mononuclear cells and provide further evidence that LPS-induced neopterin in macrophages may act by IFN-gamma-independent mechanisms.

[A case report of pulmonary embolectomy for acute pulmonary embolism]

In recent years, case reports of the pulmonary thromboembolism which had been comparatively less in our country, have been gradually increasing. However, this disease is more often reported in the chronic stage, and case reports of severe cases in the acute stage are still less. The case reported here was admitted to our hospital by emergency ambulation with severe chest pain. On the second day after the admission, respiratory standstill developed suddenly following recurrent chest pain, which necessitated cardiopulmonary resuscitation. The patient was intubated and the IABP was instituted because of hemodynamic instability. An emergent cardiac catheterization under the mechanical ventilation and the IABP supported displayed massive shadow defect on the pulmonary arteriogram, which was indicating acute pulmonary embolism. The pulmonary pressure was 58/18 mmHg despite of the shock state (the aortic pressure: 60/28 mmHg). Subsequently, a pulmonary thrombectomy was carried out under the emergency cardiopulmonary bypass. The cardiac catheterization performed two weeks after the operation. Revealed that the pulmonary pressure returned to the almost normal volume (38/18 mmHg) in association with the aortic pressure of 113/72 mmHg. The venogram of lower extremities revealed thrombi in the deep veins, suggesting the cause of the thromboembolism in the pulmonary arteries. The Bird's nest filter was inserted for the prevention of recurrence of pulmonary embolism. This patient is doing well 10 months postoperatively.

A case of adenocarcinoma of the lung with a spindle cell component

We report a 60-year-old man, who was admitted to the hospital with complaints of cough and sputum. His chest x-ray showed an abnormal mass in the right upper lobe. After admission he noticed the painful gingival tumor. Right upper lobectomy and resection of the gingival tumor were performed. Their histological features showed that the tumor consisted of a papillary and tubular adenocarcinoma mixed with a component of spindle cells. Immunohistochemical study demonstrated a positive reaction in the epithelial component for keratin and epithelial membrane antigen, and not only these epithelial markers but also vimentin were expressed in some spindle tumor cells. Electron microscopic study confirmed the biphasic pattern, showing gland formation and undifferentiated cells. We diagnose this case as adenocarcinoma of the lung with a spindle cell component and the gingival tumor was metastatic. Autopsy showed that metastatic lesions were found in the left adrenal gland and in the left kidney. The tumor cells in the left adrenal gland were composed of spindle cells and the tumor in the left kidney showed gland formation. Immunohistochemical and electron microscopic findings of surgical and autopsy specimen suggest that this tumor is of epithelial origin, and the spindle cells are derived from immature mesenchymal cell transformation of epithelial cells.

Analysis of the eicosapentaenoic acid (EPA) metabolite delta 17-6-keto-PGF1 alpha in human plasma by GC/SIM using [18O] delta 17-6-keto-PGF1 alpha

A method of the microdetermination of delta 17-6-keto-PGF1 alpha, a hydrolyzed metabolite of PGI3, is described. An authentic delta 17-6-keto-PGF1 alpha (120 mg) was prepared from eicosapentaenoic acid (EPA) incubated with homogenate of bovine aortic intima. [18O]delta 17-6-Keto-PGF1 alpha was synthesized by repeating base-catalyzed hydrolysis of methyl ester derivatives in [18O]water, to obtain an internal standard in gas chromatography/selected ion monitoring (GC/SIM) of delta 17-6-keto-PGF1 alpha. Good linear response over the range of 10 pg-10ng was demonstrated. Chromatographic conditions using a MP-65HT column presented nearly baseline separation of delta 17-6-keto-PGF1 alpha and 6-keto-PGF1 alpha. We were able to detect delta 17-6-keto-PGF1 alpha in the range from 6 to 26 pg/ml of the human plasma. The present method can be applied to the determination of delta 17-6-keto-PGF1 alpha in the human urine and plasma.