Changes in thymocytes due to aging--a study of the effects of thymic hormone on adenine nucleotides and thymocyte DNA

The number of lymphocytes (especially T-lymphocytes) in peripheral blood decreases with aging. The decline is most evident in the thymus. In this study, total AN in the thymocytes of aged mice clearly decreases from that of young mice. The quantity of thymic hormones secreted by thymic cells decreases with the organism's thymus involution with age. After demonstrating the decrease in total AN (primarily ATP) levels within the thymocytes of aged mice, we attempted to reattain the levels of younger thymocytes by the administration of various thymic hormones. Examination of DNA in the thymocytes of 4 and 58-week-old mice, using flowcytometry, showed no differences in content. However, it is significant that aged mouse thymocytes's energy level can be returned to those of young mice with the application of Th-5.

[Measurement of endotoxin in blood products using an endotoxin-specific Limulus test reagent and its relation to pyrogenic activities in rabbit]

The amounts of endotoxin in commercial blood products were measured by the turbidimetric kinetic Limulus test with an ordinary reagent (LAL-HS) and a new endotoxin-specific reagent (LAL-ES). LAL-ES contains a sufficient amount of a water-soluble (1----3)-beta-D-glucan derivative as a blocker of the (1----3)-beta-D-glucan-mediated coagulation pathway in the reaction of the Limulus amebocyte lysate. The amounts of endotoxin in albumin and globulin products measured with LAL-ES agreed with pyrogenic activities in rabbits, but those measured with LAL-HS did not. Added endotoxin in the blood products was well recovered with LAL-ES, but that in some products was excessively recovered with LAL-HS. The amounts of endotoxin in diphtheria-pertussis-tetanus combined vaccines measured with LAL-HS and LAL-ES agreed with the pyrogenic activities in rabbits. The results suggested the existence of a false-positive substance like beta-glucan in the blood products but not in the vaccine. LAL-ES is more suitable for the detection of endotoxin in blood products than LAL-HS.

Singlet oxygen production and photobiological effects of pinacyanol chloride on yeast Saccharomyces cerevisiae

Photobiological activities of pinacyanol chloride (PC), which is known as a non-intercalating dye, were investigated. Irradiation of PC-sensitized yeast cells in the dark brought about marked decrease of survival and induction of "petites" which are respiration-deficient mutants caused by partial loss of mitochondrial deoxyribonucleic acid. Nuclear mutation represented by reversion from Trp- to Trp+ was also induced by photodynamic action of PC. This fact suggested photoactive dyes are not necessarily intercalated for inducing mitochondrial and nuclear mutation. Singlet oxygen production was determined in the photoirradiated PC solution by electron spin resonance spectrometry. Photobiological effects of PC might be brought about mainly by a type II photodynamic mechanism.

Increased de novo purine synthesis by insulin through selective enzyme induction in primary cultured rat hepatocytes

The proliferative effect of insulin on de novo purine synthesis and on the expression of various enzymes of purine metabolism were studied in primary cultured rat hepatocytes. Insulin greater than 1.5 x 10(-8) M increased DNA and de novo purine synthesis to 260-390 and 270-420%, respectively, 24 and 8 h after the administration. Insulin at 1.5 x 10(-7) M increased the specific activity of amidophosphoribosyltransferase (ATase) to 154-180%, hypoxanthine-guanine phosphoribosyltransferase to 129%, and adenine phosphoribosyltransferase (APRT) to 205%, in contrast to unchanged xanthine dehydrogenase at 80%. Enzyme induction was supported by the results of kinetic analysis and the inhibition of the insulin-induced increase in enzyme activities by protein synthesis inhibitors. Insulin increased ATP to 127% and decreased AMP, ADP, 5'-guanylic acid (GMP), and guanosine 5'-diphosphate (GDP), respectively, to 73, 69, 73, and 69%. Insulin increased adenylate energy charge from 0.83 to 0.90 without changing total feedback inhibitory potential on ATase. No obvious increase of 5-phosphoribosyl-1-pyrophosphate supply was suggested, although its apparent availability for purine ribonucleotide synthesis was increased to 208-245%, reflecting mainly induced APRT activity to 205%. It is concluded that hepatocyte proliferation by insulin, as evidenced by purine metabolism, is mediated by the selective gene activation of anabolic enzymes and increased ATP as the basis to activate multiple metabolic pathways without remarkable changes of substrate availability or feedback inhibition.

Inflammatory bowel diseases and thymus disorder: reactivity of thymocytes with monoclonal antibodies

Thymectomy is one of the most effective means of treating myasthenia gravis (MG). Formation of lymphoid follicles in the thymus is seen at high rate in ulcerative colitis (UC) as well as MG. We examined the subsets of lymphocytes in the thymuses taken from patients with inflammatory bowel diseases (IBD), using OK series monoclonal antibodies. Decreases in OKT8 (CD8)-, 6(CD1)- and 10-positive cells and an increase of IA1-positive cells were observed in UC. In contrast, there were no significant changes in Crohn's disease (CD). Therefore, the thymocytes from UC appear to consist of comparatively matured cells under the influence of thymic hormone.

Multiple elements in the promoter of granulocyte colony-stimulating factor gene regulate its constitutive expression in human carcinoma cells

Some human carcinoma cells constitutively produce granulocyte colony-stimulating factor (G-CSF) which stimulates the proliferation and differentiation of the progenitor cells of neutrophilic granulocytes. By introducing mouse G-CSF chromosomal gene or its promoter DNA into human carcinoma cell lines of CHU-2, SK-HEP-1, and U-87MG, it was shown that the constitutive expression of G-CSF in these carcinoma cells was due to the intrinsic activation of nuclear factors which work on the promoter region of the G-CSF gene. A series of 5' deletion mutants, linker scanning mutants, and internal deletion mutants was constructed in the promoter of mouse G-CSF gene and was introduced into human CHU-2 cells to analyze their promoter activities. These studies demonstrated that at least three regulatory elements in the promoter of the G-CSF gene are essential for the constitutive expression of G-CSF in CHU-2 cells. These elements include the consensus decanucleotide "GAGRTTCCA/CC" present on G-CSF, granulocyte/macrophage colony-stimulating factor, and interleukin 3 genes and the "ATTTGCAT" octamer transcription factor binding site. Some point mutations in these consensus sequences significantly diminished the promoter activity in CHU-2 cells.

In vitro effect of thymic epithelial culture supernate on cyclic GMP levels in rabbit platelets

When supernatants of thymic epithelial cell cultures (STEC) or thymosin fraction 5 were incubated with washed platelets (37 degrees C for 30 min), the levels of platelet guanosine 3',5'-cyclic monophosphate (cyclic GMP) were increased in a dose-dependent manner. In contrast the supernatants from Chang, HeLa, or HCC-M cell cultures did not significantly affect the levels of intracellular cyclic GMP. The increment of intracellular cyclic GMP levels following treatment with STEC increased with longer incubation times until a plateau was reached at 30 min. This activity of STEC was found in fractions with a molecular weight below 10,000 daltons. Contents of guanine and guanosine in STEC were lower than those observed in other culture supernatants. STEC did not affect guanylate cyclase activity in platelets, but significantly inhibited cyclic GMP phosphodiesterase activities in platelet soluble and membrane fractions. Thymosin fraction 5 inhibited the phosphodiesterase activity of the soluble but not the membrane fraction.

Thrombopoietic activity of human interleukin-6

Thrombopoietin (TPO), a regulatory factor in platelet production, was purified from the conditioned medium of TNK-01 cells cultured in the presence of human interleukin-1. The N-terminal sequence of purified TPO was determined to be VPPGEDSKDVAAPHRQPLT, identical to that of the N-terminal region of human interleukin-6 (IL-6). Two forms of TPO with molecular masses of 24 and 27 kDa were identified as IL-6 by Western analysis using an anti-IL-6 antibody. Commercial recombinant human IL-6 produced in Escherichia coli, stimulated megakaryocyte colony formation in the presence of mouse interleukin-3 and increased the number of peripheral platelets in mice in a dose-dependent manner. From these results, it is concluded that human IL-6 has thrombopoietic activity.

Alkaline phosphatase of rat intestinal lymph: its characterization and the effect of fat administration

Biological characteristics of alkaline phosphatase (ALP) from rat intestine were compared among four various fractions (brush border, cytosol, luminal and lymph) to clarify the source and route of ALP appeared in intestinal lymphatics. ALP of each fraction had the same Km values and the same heat stability and all were of intestinal type. However, lymph and cytosol ALP showed similar affinity to three kinds of lectins and were distinct from membrane and luminal ALP. On polyacrylamide gel electrophoresis (PAGE), there seems to be two types of charge isomers of intestinal ALP, namely brush border type and lymph type. On sodium dodecyl sulfate (SDS)-PAGE, the molecular weight of principal band for each form was: 130,000 for brush border type, and 160,000 for lymph type. Fat administration significantly increased the ALP activity in intestinal lumen and intestinal lymph. However, it did not change biological characteristics of ALP including binding ability to lectins and electrophoretic mobility in any of these four fractions. These results suggest that lymphatic ALP may be transported from cytosol of intestinal cells and that fat administration seems to induce quantitative change of intestinal ALP, but not to change its physiological route of transportation into intestinal lymph.

[Let's study pharmacokinetics related to anesthesiology by using computer graphics: inhalation anesthetics]

The pharmacokinetics of inhalation anesthetics has been out of public interest for 20 years. Partition coefficient or solubility of anesthetic, an important determinant of uptake and distribution of inhaled anesthetics, may be the only remains of the pharmacokinetics of inhaled anesthetics. There still, however, are a few evidences which can not be explained by partition coefficient of anesthetic. The authors applied three compartment model to the rise of the blood concentration of anesthetics, i.e., nitrous oxide, enflurane, halothane, and diethyl ether. We revealed that the change in the blood anesthetic concentration may be related to the size of compartments and their time constants. The size of compartments and their time constants may be determined by interaction of partition coefficient of anesthetic and blood distribution to the tissues which may be different with different anesthetic, and may also be different when the blood concentration of anesthetic is different.

Halothane enhances the phosphorylation of H1 histone and rat brain cytoplasmic proteins by protein kinase C

The effect of halothane, a typical volatile anesthetic, on the calcium- and phospholipid-dependent protein kinase (PKC), which is one of the key enzymes of membrane signal transduction, was examined. PKC was partially purified from the cerebral tissue of male Wistar rats. Halothane increased PKC-mediated phosphorylation of calf thymus H1 histone in the presence or absence of phorbol ester or diolein, and also increased phosphorylation of the rat brain cytosolic proteins (47 kDa and 80 kDa). A similar but slight increase in H1 histone phosphorylation was observed with isoflurane and enflurane, less lipid soluble volatile anesthetics. These findings suggest that halothane may increase PKC-mediated phosphorylation by the modification of phospholipid membrane and affect membrane signal transduction of the nerve cell under the anesthetic state.

Response of Müller cells following experimental lensectomy-vitrectomy

We used morphological, biochemical and immunohistochemical methods to assess the response of Müller cells after experimental lensectomy-vitrectomy in rabbits. We observed widened intercellular spaces between the Müller cells and nerve fibers of ganglion cells, and increased electron opacity in the Müller cells of eyes injected with silicone oil. No apparent morphological changes were detected in the Müller cells of air-injected eyes. The specific and total activities of Müller cell-marker enzymes (glucose 6-phosphatase and glutamine synthetase) showed an initial increase, followed by a decrease. Glial fibrillary acidic protein immunoreactivity was not found in the Müller cells of the normal rabbit retina but was exhibited after surgery. Our results showed that markers of Müller cells associated with glycogenolysis and/or gluconeogenesis, glutamate-glutamine cycle and cytoskeletal protein metabolism were affected by the experimental lensectomy-vitrectomy.

Roles of muscularis mucosae and myofibroblasts in the healing process of acetic acid-induced ulcer

The changes in the localization of FITC-phalloidin-positive smooth muscle cells and interstitial cells were studied in control and acetic acid-treated rat fundic mucosa. In the control rats, the FITC-phalloidin-positive cells mostly corresponded to the smooth muscle cells of the muscularis mucosae, and the arteriolar and venular smooth muscle cells. On the other hand, 1 week after the acetic acid treatment, the fluorescence of the smooth muscle cells of the muscularis mucosae disappeared and a large number of fluorescent interstitial cells, probably corresponding to myofibroblasts, appeared in the regenerated mucosal layer. Three weeks after the application, severely thickened fluorescent muscularis mucosae were formed and the fluorescence of the interstitial cells was rather decreased.

Tissue and species distribution of mRNA encoding two ADP-ribosylation factors, 20-kDa guanine nucleotide binding proteins

Cholera toxin catalyzed ADP-ribosylation of Gs alpha, the stimulatory guanine nucleotide binding protein of the adenylyl cyclase system, is enhanced by approximately 20-kDa guanine nucleotide binding proteins, termed ADP-ribosylation factors or ARFs. ARF is an allosteric activator of the A1 catalytic protein of the toxin. Bovine ARF cDNA clones, ARF-1 isolated from adrenal (Sewell & Kahn, 1988) and ARF-2B from retina (Price et al., 1988), exhibit nucleotide and deduced amino acid sequences that are 80% and 96% identical, respectively, in the coding region. To determine tissue and species distribution of ARF-like mRNAs, bovine ARF-2B and human ARF-1 cDNAs and 30- or 48-base oligonucleotide probes that distinguish between ARF-1 and ARF-2B cDNAs in coding and 3'-untranslated regions were used for Northern analysis of poly(A+) RNA from different tissues and species. On the basis of hybridization with specific oligonucleotide probes, all bovine tissues contained mRNAs of 1.7 and 2.1 kb that were related to ARF-1 and ARF-2B, respectively. Northern analysis of brain poly(A+) RNA from different species with ARF-2B and ARF-1 cDNAs at low stringency demonstrated several bands varying in size from 0.9 to 3.7 kb. A 1.7-kb band consistently hybridized with an ARF-1 30-base coding-region probe but not with a probe for the 3'-untranslated region. Similar ARF-2B oligonucleotide probes did not hybridize with rat, mouse, rabbit, or human brain mRNA. Cleavage of ARF-2B cDNA with PvuII generated two fragments, one containing coding and the other 3'-noncoding region.(ABSTRACT TRUNCATED AT 250 WORDS)

[Case of skeletal open bite treated with orthognathic surgery, with special reference to morphological and functional analysis of the tongue]

Malfunction and abnormal posture of the tongue has been thought to be one of etiological factors for skeletal open-bite at length. In this study, an adult female patient with anterior open-bite is reported, who has been treated by means of posterior maxillary osteotomy and has obtained a good occlusion and profile, which is stable throughout the retention period. Electromyography was obtained from the tongue muscles by surface electrodes and the tongue muscle activity during deglutition was measured before and after surgery. The tongue posture was also analyzed on the basis of the roentgen cephalogram with the mandible at the rest position. Larger tongue muscle activities during swallowing was revealed compared to the control subjects. In addition, anteriorly and superiorly positioned tongue was seen in the initial stage. The amplitudes of the tongue muscle had decreased and tongue posture had shifted posteriorly and inferiorly following surgery, which approximated to the those observed in the control subjects. These improvements of the abnormal activity and posture of the tongue and the stability of occlusion after surgery confirmed that posterior maxillary osteotomy is an effective surgical operation for the anterior open-bite patients in terms of prognosis.

Thymic abnormalities and autoimmune diseases

Autoimmune diseases such as ulcerative colitis (UC) and myasthenia gravis (MG) are frequently associated with thymic abnormalities. Thymus hyperplasia and/or thymoma have been demonstrated in all cases with both of these two diseases by pneumomediastinography (PMG). In the diseases of digestive organs from which we can easily obtain the local information through the endoscopic observation and biopsy specimens, lots of immunological abnormalities have been accumulated. Antibody-dependent cell-mediated cytotoxicity mechanism has been demonstrated to play an important role in the mucosal destruction in UC. In the peripheral blood level of this disease, immunological abnormalities have been demonstrated such as the presence of lymphocytes sensitized by certain antigens, autoantibodies and disturbances of lymphocyte subpopulations. In the level of the thymus, the retrovirus has been detected in the thymus epithelial cells. The supernatant of thymus epithelial cell culture (STEC) has the capability of differentiating human bone marrow cells and of facilitating disease-specific immune abnormalities. Moreover, the serum factors (thymus growth factor) discovered in the patients with UC and MG, have been demonstrated to alter the thymic environments. Therefore, it is postulated that thymectomy is beneficial to exclude these abnormalities and it has been evaluated to be very effective in UC and MG clinically. From these observations, it is thought to be important to investigate the immunological abnormalities of autoimmune diseases from the viewpoints of three immunological levels, the level of disease-specific organ, the peripheral blood level and the level of the thymus. And it is important that the therapeutic plans should be decided in the consideration of the abnormalities in each immunological level.

Protein-losing enteropathy in systemic lupus erythematosus. Observations by magnifying endoscopy

We report a 35-year-old man with systemic lupus erythematosus and an associated protein-losing enteropathy that was most likely due to mesenteric venulitis or thrombosis. Evaluation of the patient's intestinal abnormality was aided by the use of magnifying endoscopy; the duodenal villi were lustrous and swollen and of various size, a pattern different from that previously described for intestinal lymphangiectasia. The patient was treated with corticosteroids, resulting in a good clinical response and return of the villi to normal shape and size.

Arterial infusion of combination therapy using dibutyryl adenosine 3',5'-monophosphate and mitomycin C for hepatocellular carcinoma occluding main portal vein: case studies

Intraarterial infusion therapy combining dibutyryl adenosine 3',5'-monophosphate and mitomycin C was administered to 8 patients with hepatocellular carcinoma occluding the main portal vein. Three patients survived more than nine months, including 1 who has been well for forty-eight months with technical imaging showing complete regression. A decreased level of serum alpha-fetoprotein of more than 90% was obtained in 38% of patients. Causes of death included hepatic failure, rupture of esophageal varices, acute gastric ulcer, and cerebral hemorrhage. It is concluded that the combination therapy may be useful for HCC.

Hepatitis B virus DNA integration in hepatocellular carcinomas and their adjacent non-neoplastic liver tissues

Hepatitis B virus (HBV) DNA integration was studied in 24 hepatocellular carcinoma (HCC) tissues obtained at operations or autopsies. In 11 cases whose sera were positive for hepatitis B virus surface antigen (HBsAg), HBV DNA integration was demonstrated by Southern blot analysis. Only one of 6 cases whose sera were positive for hepatitis B surface antibody (HBsAb) but negative for HBsAg revealed the integration and the other 5 cases revealed no HBV DNA integration. HBV DNA amplification was noted in 4 of these 6 cases in which HBV DNA integration was found when compared with the adjacent liver tissues. The integration pattern of HBV DNA was different in one case between primary HCC tissue and a metastasized lymph node. It is suggested that HBV DNA amplification is not directly related to the development of HCC and that there are polyclonal tumor cells which have different patterns of virus genome integrations.

Vasodilator actions of HA1077 in vitro and in vivo putatively mediated by the inhibition of protein kinase

The in vitro and in vivo vasorelaxant effects of HA1077, 1-(5-isoquinolinesulphonyl)-homopiperazine HCl, a novel vasodilator were examined. The inhibitory effects of HA1077 on contractile responses to various agonists were examined on strips of rabbit aorta. The concentration-response curves to 5-hydroxytryptamine, prostaglandin F2alpha, histamine, angiotensin II, noradrenaline and dopamine were concentration-dependently shifted to the right in the presence of HA1077 (0.3-3.0 microM). The in vivo vasodilator effects of HA1077 were examined in the constant-pressure autoperfused coronary vascular bed of dogs. Intra-coronary administration of HA1077 (3-30 micrograms per dog) dose-dependently increased coronary blood flow (CBF), with no effect on mean blood pressure (MBP) or heart rate (HR). Intra-coronary infusion of atropine, propranolol or diphenhydramine did not modify the in vivo coronary vasodilator response to HA1077. To determine the flow profile for HA1077 in dogs, blood flow in four vascular beds was measured, by use of noncannulating electromagnetic flow probes. HA1077 (0.01-0.3 mg kg-1, i.v.) dose-dependently decreased MBP and increased vertebral blood flow (VBF), CBF, renal blood flow (RBF) and femoral blood flow (FBF). A haemodynamic analysis showed that continuous i.v. infusion of HA1077 (0.01 and 0.033 mg kg-1min-1) dose-dependently decreased peripheral vascular resistance and increased cardiac output. There were no significant changes in right atrial pressure, dP/dt or ventricular minute work. The effects of HA1077 on various enzymes considered to be related to the regulation of smooth muscle contraction were examined. HA1077 had little effect on cyclic nucleotide phosphodiesterases, yet it potently inhibited protein kinases such as cyclic nucleotide dependent protein kinases and Ca2+/calmodulin dependent myosin light chain kinase. The present study demonstrates that HA1077 is a novel type of arterial vasodilator.

Arginine-specific ADP-ribosyltransferase from rabbit skeletal muscle sarcoplasmic reticulum is solubilized as the active form with trypsin: partial purification and characterization

Arginine-specific ADP-ribosyltransferase from rabbit skeletal muscle sarcoplasmic reticulum was solubilized as the active form with trypsin. The enzyme was partially purified by subsequent chromatography, successively on DE-52, Con A-Sepharose and Sephadex G-75. An approximately 2,000-fold purification was achieved from the 105,000 x g supernatant of trypsin-treated membrane with a recovery of 2.8%. Dithiothreitol, which activates hen liver nuclear ADP-ribosyltransferase, inhibited the enzyme.