Acta Medica Okayama 37巻 3号

Repair polymerases participating in unscheduled DNA synthesis in isolated liver nuclei, bleomycin-treated permeable cells and in ultraviolet-irradiated living cells were studied using two specific inhibitors of DNA polymerases, aphidicolin and 2', 3'-dideoxythymidine-5'-triphosphate. Unscheduled, i.e., repair, DNA synthesis in rat liver nuclei, and in bleomycin-treated permeable SR-C3H/He and XC cells was mostly attributed to DNA polymerase beta. Unscheduled DNA synthesis in human liver nuclei, bleomycin-treated permeable HeLa and HEp-2 cells, and in ultraviolet-irradiated HeLa, HEp-2 and XC cells was partially inhibited by the polymerase alpha-specific inhibitor, aphidicolin. The results suggested that both DNA polymerase alpha and beta participated in unscheduled DNA synthesis, though the respective degrees of participation differed depending on cell type and the nature and degree of DNA damage.

We studied the effects of a splenectomy in combination with immunotherapy on the survival of patients who had undergone a total gastrectomy. It was found that a splenectomy was not effective against advanced gastric cancer at stage III, and that the spleen should be retained for immunotherapy. Splenectomy for gastric cancer at terminal stage IV, particularly in combination with immunotherapy, produced not only augmentation of cellular immunity, but also increased survival.

Central fibromas developing from within the jaw bone are comparatively rare in contrast to fibromatoid lesions in other parts of the oral region. We report a 13-year-old girl with a central fibroma which developed in the jaw bone.

Levels of gamma-aminobutyric acid (GABA) in cerebrospinal fluid (CSF) were measured by radioreceptor assay (RRA) in 25 normal controls and in 121 patients with various central nervous system disorders. CSF-GABA levels could be measured down to 5 pmoles/ml reliably by this assay. In normal controls, the mean (+/- SEM) GABA level in CSF was 127 +/- 5.2 pmoles/ml. There was no correlation between age, sex and the CSF-GABA level in normal controls. The lowest CSF-GABA level, which was 60 +/- 6.0 pmoles/ml, was observed in alcoholic patients suffering from cerebellar ataxia. The CSF-GABA levels were quite low in patients with Alzheimer's disease, late cortical cerebellar atrophy, neuro-Behcet's syndrome, olivopontocerebellar atrophy, Huntington's chorea, Parkinson's disease and cerebral hemorrhage. On the other hand, the CSF-GABA levels of meningitis patients were significantly increased. These findings suggest that measuring the CSF-GABA level is quite beneficial in the diagnosis and pathophysiological determinations of some diseases.

45Ca uptake and histamine release was examined in mast cells from rats sensitized with ovalbumin and Bordetella Bertussis as an adjuvant. The uptake of 45Ca by the mast cells was significantly increased by stimulation with ovalbumin as was the release of histamine from the mast cells. Nifedipine, a calcium antagonist, inhibited the increase in both 45Ca uptake and histamine release stimulated by ovalbumin, though the effect on 45Ca uptake was stronger than that on histamine release.

The oncogenicity of xenotropic pseudotype Kirsten murine sarcoma virus (MSV) was investigated in Sprague-Dawley rats. When fetal or newborn rats were inoculated intracerebrally with xenotropic pseudotype MSV, brain tumors developed after about one month. Tumors were induced both in the cerebrum and the cerebellum. Histologically, the tumors were predominantly glioblastoma multiforme and hemangioendotheliomas. In cerebellar lesions, malignant transformation of vascular endothelial cells, polycystic areas and numerous giant cells were noted. Proliferation of Purkinje cells was also observed in some of the cerebellar tumors. Inoculation of the same virus by other routes, such as s.c., i.p. and i.m., also caused cerebral and cerebellar tumors. Brain tumors thus induced were transplantable subcutaneously into suckling rats.

That blood transfusions aid kidney graft survival is well known. Our data show that blood transfusions, except for the red blood cell component, promote growth of transplanted tumors in mice. These clinical and experimental observations suggest that blood transfusions may induce some immunological tolerance.

Characteristics of muscarinic acetylcholine (ACh) receptors were studied in the rat central nervous system (CNS) using 3H-quinuclidinyl benzilate (QNB), an antagonist of muscarinic ACh receptors. Scatchard analysis indicated that the rat CNS had a single 3H-QNB binding site with an apparent dissociation constant (Kd) of 5.0 X 10(-10) M. Li+, Zn++ and Cu++ had strong effects on 3H-QNB binding which indicates that these metal ions might play important roles at muscarinic ACh receptor sites in the brain. Since antidepressants and antischizophrenic drugs displaced the binding of 3H-QNB, the anticholinergic effects of these drugs need to be taken into account when they are applied clinically. The muscarinic ACh receptor was successfully solubilized with lysophosphatidylcholine. By gel chromatography, with a Sepharose 6B column, the solubilized muscarinic ACh receptor molecule eluted at the fraction corresponding to a Stokes' radius of 6.1 nm. With the use of sucrose-density-gradient centrifugation, the molecular weight of the solubilized muscarinic ACh receptor was determined to be about 90,000 daltons. The regional distribution of 3H-QNB binding in rat brain was examined, and the highest level of 3H-QNB binding was found to be in the striatum followed by cerebral cortex and hippocampus, indicating that muscarinic ACh mechanisms affect CNS function mainly through these areas.

A tumor of nerve origin is relatively rare in the oral region. We report a neurofibroma of the tongue observed in a 34-year-old woman.

A total of 252 bladder-washing and voided specimens from normal, and inflammatory and malignant lesions were examined by a direct mapping technique, i.e., a combined use of light (LM) and scanning electron microscopy (SEM). A newly-designed mesh, which consists of a piece of gelatine-covered, osmium-impregnated and polylysine-coated glass-slip with 42 compartments/25 mm2, was used in this study. This mesh permitted us to directly correlate LM and SEM images, which resulted in a shortening of the observation time. Malignancy of exfoliated urothelial cells has been determined on the basis of the presence or absence of pleomorphic microvilli as observed by SEM. Subsequently, a new "SEM grading" system for human urinary cytology was proposed. The direct mapping technique has enhanced the accuracy of the diagnosis over conventional methods, especially in cases of noninvasive, low-grade malignant tumors of the urinary bladder.

Sulfated acidic mucopolysaccharides have been found to be significant components of "protein plugs" in patients with chronic pancreatitis. The precise identification of the mucopolysaccharides and their distribution within the protein plugs may clarify the pathogenesis of the plugs. Pure pancreatic juice from five patients with chronic pancreatitis was obtained by endoscopic retrograde catheterization of the papilla of Vater. Enzymes for digestion of the plugs included hyaluronidase of the bovine testes and streptomyces hyalurolyticus, chondroitinase ABC and AC, and sialidase (neuraminidase). Our study indicated that: I) Sialic acid is distributed throughout the plugs and may be a major component, followed by a lesser amount of chondroitin sulfate B. 2) Chondroitin sulfate A, C, D and E and chondroitin may be minor components. 3) Hyaluronic acid is negligible in the plugs.