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Biomedical subjects

K Ochi

Publications and source records attributed to K Ochi.

At least 37 records · Page 2Linked to original sources

Presence of 22-kDa protein reacting with sera in piglets experimentally infected with Brachyspira hyodysenteriae.

In order to examine the effect of spectinomycin on outbreaks of swine dysentery, experimental infection of piglets with Brachyspira hyodysenteriae was carried out. Feed with and without spectinomycin (SP) was given to each piglet ad libitum and the susceptibility of the piglets to infection with B. hyodysenteriae was compared between SP-treated and untreated piglets. The results showed that the SP-treated piglets did not display clinical signs of swine dysentery unlike the untreated piglets. The sera obtained from these piglets were examined by the microscopic agglutination test and antibodies to B. hyodysenteriae in both groups of experimentally infected piglets were detected and the reaction was serogroup-specific. The agglutination titers were very high in the untreated piglets with dysentery while the titers in the SP-treated piglets were lower than those in the untreated piglets. In addition, the immunoblotting technique was applied and the results demonstrated that 22- and 17-kDa proteins in strain ATCC 31212 (serogroup B) reacted strongly with the sera from the untreated piglets but not with the sera from the SP-treated piglets. The 22- and 17-kDa proteins also reacted with strain ATCC 27164 (serogroup A) which belongs to a different serogroup. The 22- and 17-kDa proteins were also confirmed in six other strains of B. hyodysenteriae which belong to six different serogroups. These proteins were sensitive to proteinase K. These results indicate that the 22- and 17-kDa proteins are common to eight strains of B. hyodysenteriae which differ serologically from each other.

Agglutination Tests↗

High frequency of inactivation of the imprinted H19 gene in "sporadic" hepatoblastoma.

Embryonal tumors such as Wilms' tumor (WT), embryonal rhabdomyosarcoma (eRMS) and hepatoblastoma have been thought to have a common pathogenetic mechanism. H19 was found to be inactivated in WT and eRMS either by loss of heterozygosity or by hypermethylation of the maternal allele. We show here that the expression of the H19 gene is inactivated by maternal allelic loss or hypermethylation in 7 out of 8 "sporadic" hepatoblastomas. Furthermore, we analyzed expression of the IGF2 gene. Loss of imprinting of the IGF2 gene was detected and linked to inactivation of the H19 gene in 2 hepatoblastomas. However, 2 sporadic cases demonstrated monoallelic expression of the IGF2 gene with inactivation of the H19 gene. Our results suggest that H19 may play a role as a common imprinted tumor suppressor gene in "sporadic" hepatoblastomas but may at times work independently of IGF2 expression.

Child↗

The lethal effect of a benzamide derivative, 3-methoxybenzamide, can be suppressed by mutations within a cell division gene, ftsZ, in Bacillus subtilis.

3-Methoxybenzamide (3-MBA), which is known to be an inhibitor of ADP-ribosyltransferase, inhibits cell division in Bacillus subtilis, leading to filamentation and eventually lysis of cells. Our genetic analysis of 3-MBA-resistant mutants indicated that the primary target of the drug is the cell division system involving FtsZ function during both vegetative growth and sporulation.

Bacillus subtilis↗

Clinical evaluation of cholecystokinin-A- receptor antagonist (loxiglumide) for the treatment of acute pancreatitis. A preliminary clinical trial. Study Group of Loxiglumide in Japan.

The therapeutic effects of loxiglumide on human acute pancreatitis was investigated in 104 Japanese institutes from October 1992 to March 1994. Acute pancreatitis was diagnosed by the Japanese Criteria of Acute Pancreatitis. Soon after the diagnosis was made, one of three doses of loxiglumide (100, 300 and 500 mg/day) were injected intravenously twice a day for 14 days. The efficacy of the treatment was evaluated by clinical signs, physical signs, and biochemical findings. 189 patients were included in this trial. The clinical signs, such as abdominal pain, disappeared in 20% of the patients on the 1st day after treatment, and the rate of improvements increased thereafter. Physical signs also improved. Serum amylase levels returned to normal within 3 days after treatment, and serum lipase showed almost the same changes as serum amylase levels, but serum lipase levels in the high-dose group (500 mg/day) returned to normal more quickly compared with the other two doses. It is concluded that the cholecystokinin A receptor antagonist, loxiglumide, may become a useful drug in the treatment of acute pancreatitis in man, although more detailed investigations are needed.

Abdominal Pain↗

Cochlear function of guinea pigs with experimental chronic renal failure.

This study aimed to evaluate electrophysiologically the cochlear function of guinea pigs that underwent a five-sixths nephrectomy and, additionally, to explore the synergistic action between chronic renal failure (CRF) and noise. Cochlear potentials were recorded at 1, 2, and 3 months postoperatively. Slight changes in compound action potential and cochlear microphonics were seen at 1 month postoperative, while moderate and profound changes were seen at 2 and 3 months. Endocochlear potential showed no significant reduction. The results indicate that CRF may be an etiologic factor for cochlear dysfunction and that the hair cells seem likely to be a main site of the lesion. One-month-postoperative animals were exposed to a broadband noise. In contrast to control animals, the test animals demonstrated no recovery from the decrease in compound action potential and cochlear microphonics that occurred immediately after noise exposure. This suggests a synergistic interaction between CRF and noise.

Animals↗

The Ruffini ending as the primary mechanoreceptor in the periodontal ligament: its morphology, cytochemical features, regeneration, and development.

The periodontal ligament receives a rich sensory nerve supply and contains many nociceptors and mechanoreceptors. Although its various kinds of mechanoreceptors have been reported in the past, only recently have studies revealed that the Ruffini endings--categorized as low-threshold, slowly adapting, type II mechanoreceptors--are the primary mechanoreceptors in the periodontal ligament. The periodontal Ruffini endings display dendritic ramifications with expanded terminal buttons and, furthermore, are ultrastructurally characterized by expanded axon terminals filled with many mitochondria and by an association with terminal or lamellar Schwann cells. The axon terminals of the periodontal Ruffini endings have finger-like projections called axonal spines or microspikes, which extend into the surrounding tissue to detect the deformation of collagen fibers. The functional basis of the periodontal Ruffini endings has been analyzed by histochemical techniques. Histochemically, the axon terminals are reactive for cytochrome oxidase activity, and the terminal Schwann cells have both non-specific cholinesterase and acid phosphatase activity. On the other hand, many investigations have suggested that the Ruffini endings have a high potential for neuroplasticity. For example, immunoreactivity for p75-NGFR (low-affinity nerve growth factor receptor) and GAP-43 (growth-associated protein-43), both of which play important roles in nerve regeneration/development processes, have been reported in the periodontal Ruffini endings, even in adult animals (though these proteins are usually repressed or down-regulated in mature neurons). Furthermore, in experimental studies on nerve injury to the inferior alveolar nerve, the degeneration of Ruffini endings takes place immediately after nerve injury, with regeneration beginning from 3 to 5 days later, and the distribution and terminal morphology returning to almost normal at around 14 days. During regeneration, some regenerating Ruffini endings expressed neuropeptide Y, which is rarely observed in normal animals. On the other hand, the periodontal Ruffini endings show stage-specific configurations which are closely related to tooth eruption and the addition of occlusal forces to the tooth during postnatal development, suggesting that mechanical stimuli due to tooth eruption and occlusion are a prerequisite for the differentiation and maturation of the periodontal Ruffini endings. Further investigations are needed to clarify the involvement of growth factors in the molecular mechanisms of the development and regeneration processes of the Ruffini endings.

Acid Phosphatase↗

A novel sporulation-control gene (spo0M) of Bacillus subtilis with a sigmaH-regulated promoter.

A novel sporulation-control gene (spo0M) of Bacillus subtilis was cloned, sequenced and analyzed. The spo0M gene is located at the end of large tRNA gene clusters including rrnD and codes for a 257-amino-acid protein with a calculated size of 29.6kDa. The protein Spo0M has a strong negative charge (calculated pI=4.3) and shows no significant sequence homology to any known proteins. Gene disruption experiments revealed that spo0M is not essential for cell viability, but its disruption results in considerable impairments (decreasing by 20- to 100-fold) in sporulation. The morphological stage blocked in sporulation was stage 0 as observed by electron microscopy, and expression analysis using spo0Aps-bgaB fusion revealed an impaired gene expression of spo0A in the spo0M mutant. In contrast, spo0M disruption had no effect on antibiotic productivity. Propagation of the spo0M gene in wild-type cells using a high-copy-number plasmid also impaired sporulation, indicating that overproduction of Spo0M exerts certain negative effects on sporulation. spo0M gene expression is controlled by sigmaH, as demonstrated: (1) by monitoring expression of a bgaB transcriptional fusion integrated into the amyE locus on the chromosome of the wild-type or spo0H mutant cells, and (2) by in-vitro transcription of spo0M gene with EsigmaH.

Amino Acid Sequence↗

Carbonic anhydrase isozyme II immunoreactivity in the mechanoreceptive Ruffini endings of the periodontal ligament in rat incisor.

The present study describes the distribution of carbonic anhydrase isozyme II (CA II) in the lingual periodontal ligament of the rat incisor. Some thick nerve fibers in the nerve bundle displayed CA II-like immunoreactivity (LI) as well as non-neuronal elements such as osteoclasts. At the alveolar half of the lingual periodontal ligament of the incisor, thick CA II-like immunoreactive (-IR) nerve fibers showed a tree-like raminification, but thin and beaded CA II-IR nerve fibers were rare. Under the electron microscope, CA II-LI were diffusely localized in the axoplasm of the axon terminals surrounded by Schwann sheaths which were immunonegative for CA II. The cell bodies of the terminal Schwann cells associated with the periodontal Ruffini endings did not exhibit CA II-LI. The present immunohistochemical evidence indicates that CA II may participate in the regulation of the intra-neuronal ion in the periodontal Ruffini endings which are thought to be in a state of high neuronal activity.

Animals↗

Affinity isoelectric focusing of human serum apolipoprotein B-containing lipoproteins on agarose gels with cyclodextrins.

In an attempt to subfractionate apolipoprotein B-containing lipoproteins (apoB-Lp), agarose isoelectric focusing (IEF) of apoB-Lp in human sera was carried out in the presence of two kinds of cyclodextrins (CDs), which have different affinities for cholesterol. ApoB-Lp in the agarose gels was detected by immunofixation, followed by protein staining. In the presence of both 11.4 mg/mL alpha-CD and 3.51 mg/mL beta-CD, but not either one alone, IEF separated a maximum of six apoB-Lp bands. Electrophoresis failed to separate the apoB-Lp subfractions under similar conditions with CDs. The patterns of apoB-Lp in IEF with the CDs appeared to differ in some sera. Since the subfractions of apoB-Lp can be separated without ultracentrifugation of serum, the present method serves for the screening of apoB-Lp heterogeneity on native serum lipoproteins.

Apolipoproteins B↗

Prevention of hyperlipidemic acute pancreatitis during pregnancy with medium-chain triglyceride nutritional support.

CONCLUSION: A combination of diet therapy, nutritional support with medium-chain triglycerides (MCT), and well-planned preterm Cesarean delivery on demand is an effective measure to prevent gestational hyperlipidemic pancreatitis and leads to successful childbirth. BACKGROUND: Prevention and therapy of gestational hyperlipidemic pancreatitis are important, although difficult, because the condition carries a high maternal and fetal morbidity and mortality. RESULTS: We describe a 32-yr-old female with lipoprotein lipase-deficient familial hypertriglyceridemia who had recurrent episodes of acute pancreatitis. The third episode occurred with worsened hyperlipidemia 7 yr earlier at 32 wk of her first pregnancy and resulted in fetal death. The fourth and fifth episodes were also accompanied by marked hyperlipidemia probably caused by drug discontinuance and dietary noncompliance. She became pregnant. Serum triglyceride levels were controlled below 2000 mg/dL by strict monitoring with low-fat, low-calorie diet and MCT nutritional support. A premature but healthy infant was born by Cesarean delivery at 36 wk of gestation when the mother presented with mild abdominal pain and was found to have uterine contractions. The ensuing clinical course has been uneventful.

Acute Disease↗

In vitro protein phosphorylation associated with cellular differentiation of Streptomyces griseus.

In vitro phosphorylation reactions with crude cellular extracts revealed that phosphorylation of a 17-kDa protein is associated with the onset of aerial mycelium formation in solid culture (but not submerged spore formation in liquid culture) of Streptomyces griseus. The possible importance of the 17-kDa protein phosphorylation in cellular differentiation was further indicated by inducing aerial mycelium formation in the presence of decoyinine and in studies using certain developmental mutants (relC, afsA, and M-1). It is proposed that the 17-kDa protein may play a role in cellular differentiation of S. griseus via its phosphorylation.

Bacterial Proteins↗

An essential GTP-binding protein functions as a regulator for differentiation in Streptomyces coelicolor.

The Streptomyces coelicolor obg gene, which encodes a putative GTP-binding protein of the Obg/Gtp1 family, was characterized. The obg gene was essential for viability. Introduction of multiple copies of obg into wild-type S. coelicolor suppressed aerial mycelium formation. A single amino acid substitution at any of six positions was introduced into the GTP binding site of Obg, and the mutated proteins were expressed in wild-type cells. Obg(P168-->V) exerted a more accentuated suppressive effect on aerial mycelium formation than did the wild-type Obg protein. In contrast, Obg(G171-->A) accelerated the development of aerial mycelium. These results show that Obg protein functions as a pivotal regulator for the onset of cell differentiation through its ability to bind GTP. Western analysis revealed that expression of obg is regulated in a growth phase-dependent manner, indicating a sharp decrease just after onset of aerial mycelium development or at the end of vegetative growth. Obg was a membrane-bound protein as determined by immunoelectron microscopy.

Bacterial Proteins↗

Chronic pancreatitis: functional testing.

This article reviews the evolution of functional testing of the pancreas in Japan for the diagnosis and treatment of chronic pancreatitis (CP), contrasting the pre- with the postsecretin test (S test) era. In the pre-S test era, the diagnosis was based on symptoms, clinical findings, fasting serum diastase levels, and the vagostigmin- and ether-stimulation test unless morphologic evidence was available. The S test and CCK-pancreozymin (PZ) test (PS test) were introduced into Japan around 1963 and have been used as the gold standard of the exocrine pancreatic-function test. Through a series of attempts at standardization in 1971, 1985, and 1987, the method was standardized to collect duodenal juice for 60 min through a double- or triple-lumen tube after a bolus or during a continuous i.v. injection of secretin (100 U). The S test, however, is an invasive and cumbersome procedure. As a result, N-benzoyl-L-tyrosal-p-aminobenzoic acid (BT-PABA) testing and fecal chymotrypsin testing were introduced into Japan in the middle and late 1970s, respectively. Although simple and noninvasive, these two methods were found have lower sensitivity and specificity than the conventional S test. These two methods, therefore, are presently used more often for monitoring the course of disease and therapeutic effects. Additionally, the glucose tolerance test can be performed to detect endocrine pancreatic insufficiency.

4-Aminobenzoic Acid↗

Prolyl hydroxylase and tissue inhibitor of metalloproteinase in pure pancreatic juice in patients with chronic pancreatitis.

Prolyl hydroxylase is a key enzyme in collagen synthesis, and tissue inhibitor of metalloproteinase (TIMP) is known to suppress collagenolytic enzymes. To see whether the levels of these two enzymes in serum and human pure pancreatic juice (PPJ) are good indicators of pancreatic fibrosis in chronic pancreatitis (CP), we examined 15 controls, 14 alcoholics without evident pancreatic diseases (7 current drinkers and 7 former drinkers), and 19 patients with CP. Levels of the two enzymes were determined by a sandwich enzyme immunoassay method. TIMP-1 levels in PPJ were significantly higher in patients with CP than in controls and alcoholics, with overlap in only a few exceptional patients. A significant inverse correlation between TIMP-1 and bicarbonate output in PPJ was observed. Prolyl hydroxylase levels in PPJ, in contrast, were significantly higher in current drinkers than in patients with CP, controls, and former drinkers, with overlap in only a few exceptional patients with relapsing CP. Identical results were obtained even when the enzyme levels were expressed as nanograms per milligram of protein. Serum levels of prolyl hydroxylase and TIMP-1 showed no significant differences among controls, current alcoholics, former alcoholics, and patients with CP. These results indicate that the raised level of TIMP-1 in PPJ, unlike that of prolyl hydroxylase, is a good indicator of pancreatic fibrosis in CP.

Adult↗