Identification of a unique spotted fever group rickettsia from humans in Japan.
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Biomedical subjects
Publications and source records attributed to T Uchida.
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We examined the relationship between growth arrest of smooth muscle cells and structural changes in microfilament bundles, and also that between the structural changes and the actions of contractile agonist using a multipassagable variant cell line (SM-3) derived from rabbit aortic smooth muscle cells. The content of smooth muscle type alpha-actin increased with density-dependent growth arrest of the SM-3 cells, but was attenuated in the logarithmically growing cultures. As assessed cytochemically, the growth-arrested cells contained longitudinally oriented bundles of actin-containing microfilament and myosin-based filaments visualized with rhodamine-phalloidin and antibody against myosin light chain 20, respectively, whereas both actin- and myosin-containing structures in logarithmically growing cells showed slight, shortened, or diffused patterns. Electron microscopic examination of the growth-arrested cells revealed that the cells contained numerous and conspicuous microfilament bundles associated with many compact electron-dense bodies. In addition, pinocytotic vesicles were often found near the plasma membrane in the growth-arrested cells. SM-3 cells in the growth-arrested phase responded to prostaglandin F2 alpha (3-30 microM) and rat endothelin (0.1-1.0 microM) with a reversible contractile response, in association with monophosphorylation and/or diphosphorylation of the myosin light chain 20. However, the influence of the contractile agonists was greatly reduced during logarithmic growth. These results suggest that in the SM-3 cells in the growth-arrested phase, there is a restoration of the contractile architecture and the myosin light chain phosphorylation system. Thus, this SM-3 cell line is expected to serve as a useful model for examining biochemical and physiological phenomena of smooth muscle.
To clarify the regulation of erythropoiesis of complement (C')-sensitive erythrocytes (E) during erythroid cell maturation and differentiation in paroxysmal nocturnal haemoglobinuria (PNH), the C' sensitivity of (1) erythroblasts from erythropoietic bursts and (2) erythropoietic precursors was examined in seven patients with PNH. For the former, a modified complement lysis sensitivity (CLS) test using the trypan blue dye exclusion method was employed. For the latter, an erythropoietic cell culture following the CLS or sucrose haemolysis (SH) test for mononuclear cells was used. Linear relationships were found between the concentrations of C' and proportions of C'-mediated haemolysed erythroblasts in both PNH and normal erythropoietic bursts. In addition, PNH erythroblasts showed hypersensitivity to C'; in the C' dilution for 50% lysis was 12.5 +/- 8.1 ml in PNH patients and 42.3 +/- 4.5 ml in normal controls. There was also a significant correlation (r = 0.919; P less than 0.01) between the proportions of PNH-III E and haemolysed erythroblasts. Significant hypersensitivity of mature erythroid progenitors (CFU-E) to C' was found in both the SH (P less than 0.01 or P less than 0.05) and CLS (r = -0.712; P less than 0.001) tests in PNH patients. However, no hypersensitivity to C' was observed at the primitive erythroid progenitors (BFU-E) level in either the PNH patients or the normal controls. These findings suggest that in PNH the property of C' sensitivity appears during differentiation and maturation from BFU-E to CFU-E and that the proportions of PNH-III E are already programmed at the level of erythroblasts.
Red cell volume distribution width (RDW-CV) was examined as a means of diagnosing iron deficiency. Iron deficiency was classified as iron deficiency anaemia, prelatent or latent iron deficiency in 1648 students. MCV and RDW-CV (mean +/- ISD) in each group were 89 +/- 4 ft, 12.7 +/- 0.7% in normal individuals, 89 +/- 4 fl, 13.2 +/- 0.8% in prelatent deficiency, 86 +/- 6 fl, 14.0 +/- 1.5% in latent deficiency, and 79 +/- 7 fl, 15.6 +/- 1.7% in iron deficiency anaemia, respectively. Although microcytosis was evident only in iron deficiency anaemia, RDW-CV showed larger values concomitant with the development of iron deficiency. The sensitivity of RDW-CV for the diagnosis of iron deficiency anaemia was 77.1%, and for iron deficiency anaemia and latent deficiency 49.2%, the specificity being 90.6%. In countries with a high prevalence of iron deficiency and low thalassaemia, iron deficiency should be screened by RDW-CV determination without serum iron or ferritin measurements.
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Among 389 consecutive chronic alcoholics in whom a liver biopsy was performed for diagnostic purposes, nine patients (2.3%) had histological changes of "alcoholic foamy degeneration" (AFD), characterized by numerous small fat droplets in the swollen hepatocytes of the centrilobular area. In five cases, there were non-specific clinical features, while the other four cases presented acute hepatic decompensation with jaundice and a reduced prothrombin activity. Seven patients had high serum lipid concentrations including hypertriglyceridemia and hypercholesterolemia, which improved after withdrawal of alcohol intake. In conclusion, AFD has a broad clinicopathological spectrum including asymptomatic patients and other cases with severe liver decompensation manifested by jaundice and reduced prothrombin activity. AFD is usually associated with hyperlipemia.
Two cynomolgus monkeys were inoculated with a stool extract originally derived from patients suffering from enterically transmitted non-A, non-B hepatitis. Subsequently, the primates developed self-limiting acute hepatitis and their liver tissues were obtained sequentially by needle biopsy or at sacrifice. Histologically, the liver tissues exhibited necroinflammation which appeared in parallel, both in time and magnitude, with elevation in serum aminotransferases. Necroinflammation was characterized by focal dropout of hepatocytes with accumulation of lymphocytes and macrophages. These lymphocytes were positive for a cytotoxic/suppressor immunophenotype. The hepatocytes surrounding these focal necroses showed depletion of glycogen granules and decrease in glucose-6-phosphatase and succinic dehydrogenase activities. Ultrastructurally, damaged hepatocytes around the focal necroses revealed marked dilatation of both rough and smooth endoplasmic reticula, swelling and disruption of the mitochondria and leakage of nuclear materials into the cytoplasm. Frequently, direct contact between the damaged hepatocytes and lymphocytes was noted. Virus-like particles measuring about 27 nm in diameter were observed singly or in small groups within the cytoplasm of damaged hepatocytes. Primary hepatocyte culture of a cynomolgus monkey, inoculated with a transmissible stool extract did not show any cytopathic change, although similar virus-like particles were recognized ultrastructurally in the cultured hepatocytes. Morphological analysis of in vitro and in vivo transmission studies in cynomolgus monkeys strongly supported the hypothesis of immune-mediated hepatocytolysis rather than a direct cytopathic effect of this hepatitis virus.
In 48 children with spinal lesions and micturition problems urinary lactic dehydrogenase (LDH) isoenzymes were analyzed. They had higher total LDH activities (716.8 +/- 1,050.2 nkat/I), isoenzymes V percents (22.2 +/- 13.0%) and isoenzyme V activities (203.4 +/- 308.4 nkat/I) than those of healthy children (150.0 +/- 83.4 nkat/I, 1.9 +/- 1.0%, 5.0 +/- 3.3 nkat/I). Many subjects had an isoenzyme V-dominant LDH isoenzyme pattern. Among 48 subjects the patients with pyuria, bacteriuria or abnormal pyelograms had markedly high total LDH activities, isoenzyme V percents and isoenzyme V activities. The rise in LDH isoenzyme V levels may reflect the renal damage in the patients with neurogenic bladders.
Segments of DNA are deleted from recombinant cosmid DNAs with high frequency during propagation in standard recA Escherichia coli hosts. An attempt has been made to derive an appropriate strain of E. coli, suitable for cosmid cloning, in which such deletions do not occur. We examined the effects of a series of host recombinational mutations on the deletion process, using six independent recombinant cosmids that carry inserts of mouse, Chinese hamster, or human DNA. Various E. coli host cells carrying the recombinant cosmids were cultured serially in liquid medium, and the recombinant cosmid DNAs were extracted from the host cells and analyzed by agarose gel electrophoresis and by gene transfer of the DNAs into cultured mammalian cells. Of the mutations examined, only a recB recC sbcB recJ (or recN) quadruple combination of host mutations prevented the deletion of DNA segments. The recombinant cosmid DNAs propagated in E. coli hosts that carried this combination of mutations were functionally as well as structurally intact. We propose that the recJ (and/or recN) gene is involved in some aspect of the events that lead to deletions of cosmid DNA in a recB recC sbcB genetic background.
We examined the developmental ability of enucleated eggs receiving embryonic nuclei and male primordial germ cells (PGCs) in the mouse. Reconstituted eggs developed into the blastocyst stage only when an earlier 2-cell nucleus was transplanted (36%) but very rarely if the donor nucleus was derived from a later 2-cell, 8-cell, or inner cell mass of a blastocyst (0-3%). 54-100%, 11-67%, 6-43% and 6-20% of enucleated eggs receiving male PGCs developed to 2-cell, 4-cell, 8-cell and blastocyst stage, respectively, in culture. The overall success rate when taking into account the total number of attempts at introducing germ cells was actually 0-6%. Live fetuses were not obtained after transfer of reconstituted eggs to recipients, although implantation sites were observed. The developmental ability of reconstituted eggs in relation to embryonic genome activation and genomic imprinting is discussed.
Previously an Mr 46,000 protein (named p46) was shown to be induced in the culture medium of human hepatoblastoma cells, Huh-6 Cl-5, treated with 12-O-tetradecanoyl phorbol-13-acetate (TPA). For further characterization of p46, Huh-7 Cl-4, another line of well differentiated liver cells, was incubated in the presence and absence of TPA, and proteins were labeled with [35S]methionine, and the proteins secreted into the medium were analyzed by one- and two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis. A protein of Mr 46,000 was observed in the culture medium of Huh-7 Cl-4 cells treated by TPA or plated at low density, but only slightly in the culture medium of Huh-7 Cl-4 cells plated at high density. As these results suggested that the expression of p46 was regulated by a factor that was activated in the growth state and by TPA treatment, the effect of introduction of the competence gene c-myc into Huh-7 Cl-4 cells was examined. All 37 independent transfected colonies obtained showed enhanced expression of p46. As a control, the c-Ha-ras gene was introduced into Huh-7 Cl-4 cells and shown not to enhance expression of p46. These results strongly suggested that the expression of p46 was regulated by the competence gene c-myc.
Recombinant lambda phage DNA, encapsulated in phage particles and coprecipitated with calcium phosphate, efficiently transforms cultured mammalian cells without a requirement for carrier DNA. The present paper analyzes the stability of the transformants obtained by the phage transfer method. lambda phage particles containing recombinant DNA that includes the thymidine kinase (TK) gene of herpes simplex virus type 1 as a selective marker were introduced into Ltk- cells deficient in TK activity, and TK+ transformants were selected in HAT medium. To test the stability of the TK+ phenotype of the transformants, seven individual transformant clones were isolated, cultured in HAT selective medium and then in non-selective medium for various lengths of time. After such culture, transformants were allowed to develop colonies in both selective and non-selective medium. For all seven transformant clones, the numbers of colonies obtained in the two types of medium were almost identical, irrespective of whether or not each transformant clone had been previously cultured for 15 to 50 days in non-selective medium. This result suggests that most transformants obtained by the phage transfer method maintain the TK+ phenotype stably, for at least 50 days, when grown in non-selective medium.
Hydroxy propyl cellulose (HPC)-ethyl cellulose (EC) microcapsules containing piretanide were newly by a solvent evaporation technique and their slow-release properties were evaluated on dissolution properties in vitro and pharmacokinetic and pharmacodynamic parameters in beagle dogs. The dissolution behavior of piretanide from the microcapsules in dissolution media of pH 1.2-6.8 and the plasma piretanide level in beagle dogs varied dependently on the contents of HPC and EC. As compared with ordinary piretanide tablet on the market, the HPC-EC10 (5:3) microcapsule showed the controlled dissolution behavior, sustained plasma piretanide level, almost same AUC (area under curve), slow urinary piretanide excretion, decreased urine excretion maximum rate, and no difference in the cumulative urine volume and cumulative urinary electrolytes (Na+, K+, Cl-) excretion. HPC-EC microcapsules containing piretanide sufficiently satisfied the conditions which slow-release preparations must have.
A beta-lactam antibiotic, amoxicillin, was microencapsulated with ethylcellulose using a solvent evaporation process in liquid paraffin containing sorbitan tristearate as a dispersing agent, and the microcapsules obtained showed first-order drug release. Usage of the previous log-log relationship of cefadroxil between in vitro dissolution half-lives (T50) and the experimental release rate constants (k'r) of the drug in vivo, and the nomogram for the design of satisfactory sustained-release preparations resulted in the prediction that ethylcellulose microcapsules containing 60% amoxicillin would show the most effective sustained-release pattern. Prepared microcapsules containing various amounts of amoxicillin were administered to beagle dogs and it was found that above prediction was correct. In addition, a more precise log-log correlation concerning amoxicillin was also undertaken, good linearity was observed and the decline was very similar to that of cefadroxil.
The preventive effect of KZ-1026 on acute liver injury induced by CCl4 in rats was evaluated histochemically, enzyme-histochemically and ultrastructurally. Rats that received 50% CCl4 (2 ml/kg) intraperitoneally were sacrificed at 3, 7 and 24 hr. Remarkable reductions in hepatic glycogen, RNA and G-6-Pase activity were observed in the centrilobular area at 3 hr, and ballooned cells appeared in the mid-zone at 7 hr. At 24 hr, the above histochemical parameters in the hepatocytes of the centrilobular area and mid-zone were extensively reduced, while the number of ballooned cells in the mid-zone was increased. KZ-1026 (200 mg/kg) was given orally at 24 and 4 hr before, simultaneously with or 3 hr after CCl4 treatment, and each rat was sacrificed at 24 hr after CCl4 administration. Pretreatment with KZ-1026 24 hr before CCl4 administration prevented reduction of RNA, glycogen and G-6-Phase activity, as well as disruption of rER and proliferation of sER due to CCL4 toxicity. This preventive effect of KZ-1026 was reduced by posttreatment; however, only the decrease in cytoplasmic RNA was well prevented. These results suggested that KZ-1026 is protective against CCl4-induced acute liver injury.
Glycyrrhizin (GL) not only has an inhibitory effect on HIV replication but also exhibits interferon-inducing and natural killer (NK)-enhancing effects and improves liver dysfunction. Thus, large doses of GL (200-800 mg/day) were intravenously administered for more than 8 weeks to 9 hemophilia A patients with HIV infection (asymptomatic carrier, AC). Lymphocyte count increased in all 9 cases. OKT4 OKT8 ratio was elevated in 6 out of the 9 cases and OKT4-positive lymphocytes increased in 8 out of the 9 cases; 66.7% and 88.9% improvement, respectively. Changes in NK cell activity and mitogenic responsiveness to PHA, Con A and PWM were not significant. Liver dysfunction, noted in 4 cases, clearly improved. Serum electrolytes, protein, lipids, and renal function were within normal levels and no serious side-effects were observed during treatment. On the other hand, in 3 cases of hemophilia without HIV infection, the number of OKT4 lymphocytes was not significantly altered during treatment. From these results, large dose administration of GL to HIV-positive hemophilia patients (AC) seems to be effective in preventing development of AC into AIDS by raising the number of decreased OKT4 lymphocytes and improving liver dysfunction.
The immunocytochemical localization of amelogenins in the developing deciduous tooth germs of 6-month-old human fetuses was investigated by the protein A-gold method using an antiserum against porcine 25K amelogenin. The inner enamel epithelial cells and underlying matrix showed no amelogenin-like immunoreactivity. Distinct immunoreactivity was initially shown by fine fibrils found beneath the intact basal lamina of preameloblasts at the early differentiation stage. At the late differentiation stage, amelogenin-like immunoreactivity was shown by a fine granular material within the extracellular matrix as well as by the Golgi apparatus, secretory granules, lysosomal structures, coated vesicles, and coated pits of preameloblasts with a disrupted basal lamina. At the formative stage, the localization of immunoreactivity in secretory ameloblasts was similar to that in preameloblasts during the late differentiation stage. However, immunopositive coated vesicles and coated pits were only found at the early stage of matrix formation. The calcified enamel matrix and stippled material showed intense immunoreactivity. Immunocytochemical labeling of the enamel matrix appeared as a gradient, decreasing from the enamel surface to the dentinoenamel junction. No maturation stage of ameloblasts existed in the tooth germs examined. In predentin and dentin, amelogenin-like immunoreactivity was occasionally detected on odontoblasts and their processes, but odontoblasts and cells of the stratum intermedium contained no immunoreactive elements. These findings confirmed that the secretory ameloblast in the human deciduous tooth germ is responsible for the synthesis and secretion of enamel proteins.
The mechanism that explains the association between corticoids and acute pancreatitis is unknown. Our hypothesis was that chronic glucocorticoid treatment could adversely affect the course of hemorrhagic pancreatitis by acting through cholecystokinin (CCK) receptors. Acute necrotizing pancreatitis was induced by feeding young female mice a choline-deficient, ethionine-supplemented (CDE) diet for 60 hours. Treatment with hydrocortisone (10 mg/kg/day) was begun 1 week before pancreatitis. At the onset of the CDE diet, a group of hydrocortisone-treated mice were also given the CCK receptor antagonist CR-1409 (5 mg/kg three times a day). Control mice received injections of saline solution. A follow-up of 336 hours was conducted for survival analysis. Hydrocortisone given alone did not produce pancreatitis. Hydrocortisone, however, did increase the pancreatic necrosis caused by the CDE diet (from 40% to 70%) and significantly reduce survival (from 40% to 9%). CR-1409 completely abolished the adverse effects of hydrocortisone on pancreatitis. We measured amylase release by dispersed pancreatic acini from mice chronically treated with hydrocortisone in response to CCK-8. Treatment with hydrocortisone increased both the sensitivity and the responsiveness of the pancreas to CCK-8. We conclude that glucocorticoids alone may not induce acute pancreatitis, but they can increase the risk of a more severe form of pancreatitis developing. The glucocorticoid effect appears to be attributable to a CCK receptor-mediated sensitization of the pancreas to endogenous CCK. Thus, CCK-receptor blockade may improve survival in necrotizing pancreatitis associated with chronic glucocorticoid treatments.