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Biomedical subjects

T Sekiguchi

Publications and source records attributed to T Sekiguchi.

At least 19 recordsLinked to original sources
PubMed1992

Intra- and extracellular localization of hyaluronic acid and proteoglycan constituents (chondroitin sulfate, keratan sulfate, and protein core) in articular cartilage of rabbit tibia.

To demonstrate the intra- and extracellular localization of hyaluronic acid (HA) in articular cartilage of the rabbit tibia, biotinylated HA binding region, which specifically binds to the HA molecule, was applied to the tissue. In comparison with the localization of HA, that of chondroitin sulfate (CS), keratan sulfate (KS), and the protein core (PC) of the proteoglycan was examined by immunohistochemistry. Strong positive staining for HA was detected in chondrocytes located in the transition between the superficial and middle zones of the tissue. Pre-treatment with chondroitinase ABC, keratanase II, or trypsin enhanced the stainability for HA in peri- and intercellular matrices. Immunohistochemistry with or without enzymatic pre-treatment demonstrated that immunoreactivity for CS, KS, and PC was distinctly discerned in chondrocytes and in the extracellular matrix located in the middle and deep zones. In particular, the immunoreactivity for KS and PC was augmented by pre-treatment with chondroitinase ABC not only in chondrocytes but in the extracellular matrix located in the middle and deep zones. Microbiochemical analysis corresponded well with histochemical and immunohistochemical results. These results suggest that HA is abundantly synthesized and secreted in chondrocytes located in the transition between the superficial and middle zones.

Aggrecans↗
PubMed1992

DNA-binding domain of RCC1 protein is not essential for coupling mitosis with DNA replication.

The RCC1 protein that is required for coupling mitosis with the S phase has a DNA-binding domain in the N-terminal region outside the repeat. We found that RCC1 protein without any DNA-binding activity complemented the tsBN2 mutation with the same efficiency as that of intact RCC1 protein. In ts+ transformants of tsBN2 cells transfected with the RCC1 cDNA lacking the DNA-binding domain, an endogenous RCC1 disappeared at 39.5 degrees C, and the deleted RCC1 protein encoded by the transfected cDNA was found in the cytoplasm, but a significant amount of it was also found in the nuclei. This deleted RCC1 protein was eluted from the nuclei with the same concentration of NaCl and DNase I as was used for the intact RCC1 protein in BHK21 cells. Furthermore, the deleted RCC1 protein co-migrated with the nucleosome fraction on sucrose density gradient analysis. These results indicate that the RCC1 protein binds chromatin with the aid of other unknown protein(s). Thus, the DNA-binding domain of RCC1 protein is not essential for coupling between the S and M phases, but was shown instead to function as a nuclear translocation signal.

Amino Acid Sequence↗
PubMed1992

[Irritable bowel syndrome--criteria, sub-classification, etiology].

The irritable bowel syndrome (IBS) is a very common condition in gastroenterology clinics, but yet it is one of the pooly understood. A international working team in Rome, 1988, proposed that IBS is a functional intestinal disorder with chronic or recurrent gastrointestinal symptoms without structural or biochemical abnormalities. IBS was sub-classified into 3 groups; abdominal pain as the prominent feature with diarrhea, with constipation, with both while painless diarrhea and simple constipation without pain were excluded from IBS. There is a lot of data suggesting that IBS has a gut dysmotility, which is influenced by many stimuli (food, hormone, drug, menses, mechanical dilatation), including psychological stress. Moreover, currently available evidences implicate that IBS is a more generalized disorder of smooth muscle function not only in the intestine but also outside of the intestine.

Colonic Diseases, Functional↗
PubMed1992

[Clinical studies on cefprozil in pediatrics].

Cefprozil (CFPZ, BMY-28100) fine granules were given orally to 21 children with acute bacterial infections including 15 cases of acute tonsillitis and 3 each of acute bronchitis and urinary tract infections. Good to excellent clinical responses were obtained in 19 of the 21 patients and bacterial eradications were obtained for all 11 strains found in these cases. Loose stool and eosinophilia were observed in 1 case each. From the above clinical results, it appears that CFPZ is a useful antibiotic for the treatment of pediatric patients with various bacterial infections.

Acute Disease↗
PubMed1992

[Clinical effects of six-month short time biofiltration].

The clinical effects of six-month short time biofiltration (SBF) were evaluated using a B-A-B' study (B, B': conventional bicarbonate hemodialysis; CBHD, A:SBF) in ten patients maintained on CBHD three times a week. An F80 hemodiafilter (1.9 m2, polysulfone, Fresenius) was used. In addition to routine clinical parameters for a patient on regular dialysis treatment, plasma von Willebrand factor antigen (vWF) (an index of stimulation of vascular endothelium), and the methylguanidine/creatinine ratio (MG/Cr) and malondialdehide (MDA) (indices of the levels of oxygen radicals), were evaluated. Nine patients completed the study, one patient dropping out at the 12th week of A because of muscle cramps during SBF. The treatment time was 2 hours in six cases and 2.5 hours in three cases. The mean blood flow rate was 280 +/- 42 (SD) minutes. Using the urea kinetics model, the mean KT/V was 1.26 +/- 0.28, and the mean protein catabolic rate was 1.22 +/- 0.18 g/kg body weight/day at the end of A. No change in ultrafiltration, blood pressure, cardiac function (assessed by echocardiography), CTR, human atrial natriuretic peptide, total protein, albumin, uric acid, serum creatinine, sodium, calcium, inorganic phosphorus, vWF, or MDA was found between each period. Blood urea nitrogen, c-PTH, and MG/Cr increased during the A period. Serum magnesium and beta-2 microglobulin decreased during the A period. Blood gas results, on the whole, did not change. In a patients, however, acidosis gradually developed. An increase in substitution fluid from 5 L/session to 7.5 L/session improved the acid-base balance in that patient. In conclusion, SBF is as effective as CBHD in removing small molecules and maintaining cardiocirculatory status, and is superior to CBHD in removing beta 2-microglobulin and is less stimulative to the endothelium than CBHD.

Adult↗
PubMed1992

[Clinical effect of proton pump inhibitors on reflux esophagitis].

The clinical efficacy of proton pump inhibitors (PPI, omeprazole 20 mg or lansoprazole 30 mg), once daily, after breakfast, was studied in patients with erosive/ulcerative reflux esophagitis. The following results were obtained. 1) Twenty-four hour esophageal pH monitoring was performed before treatment and on 7th day of PPI medications. Omeprazole reduced the percent time pH less than 4 from 29.1 to 1.2 and lansoprazole from 68.0 to 2.4. 2) The cumulative disappearance rate of overall symptom was 52% after 1 week and 62% after 2 weeks with omeprazole these were 66% and 91%, and with lansoprazole respectively 3) The endoscopic healing rate was 63% was after 2 weeks and 76% after 4 weeks with omeprazole medication, and 76% and 97% respectively with lansoprazole. These results indicate that PPI medication inhibits the acid reflux almost completely and is a more useful therapeutic agent for GERD than H2-antagonists.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1992

[Clinical studies on panipenem/betamipron in pediatrics].

Panipenem/betamipron (PAPM/BP) was given by 30 minutes drip infusion to 15 children with acute bacterial infections including 11 with acute pneumonia, 2 each with staphylococcal scalded skin syndrome and urinary tract infections. Good to excellent clinical responses were obtained in all of the 15 patients and bacterial eradications were obtained for all 12 strains identified in these cases. Urticaria considered to be drug related was observed in 1 patient. Slight elevations of GOT and GPT and eosinophilia were observed in 1 case each. From the above clinical results, it appears that PAPM/BP is a useful antibiotic for treatment of pediatric patients with various bacterial infections.

Acute Disease↗
PubMed1992

Behavioral analysis of internal memory states using cooling-induced retrograde amnesia in Limax flavus.

Temporal evolution of internal memory states in a terrestrial mollusk, Limax flavus, was studied using cooling-induced retrograde amnesia. The slug was conditioned to avoid carrot odor by temporally correlated presentation of carrot juice and a bitter-taste stimulus of quinidine sulfate. We could induce retrograde amnesia by cooling of the conditioned slug immediately after the training trial. Thus, we studied the memory states in the slug using the retrograde amnesia according to strategies used in the studies of memory states in mammals or insects. In the early process of memory acquisition, at least two distinctive memory states were observed, short-term memory and long-term memory (LTM). For LTM, two states were also observed. One was a reactivated state of LTM, which was sensitive to the cooling used to induce the amnesia. The other was a so-called resting state of LTM, which was insensitive to cooling. A few days after memory acquisition, further evolution was observed in that the amnesia could not be induced even if the memory trace was reactivated. The results obtained in Limax flavus was comparable with those obtained in a variety of animals.

Amnesia↗
PubMed1991

Acute effects of intravenous nicardipine on hemodynamics and cardiac function in patients with a healed myocardial infarction and no evidence of congestive heart failure.

Acute effects of intravenous nicardipine (10 micrograms/kg) on systemic hemodynamics and cardiac function were evaluated in 17 patients with a healed myocardial infarction and no evidence of congestive heart failure. Mean New York Heart Association functional class was 1.6 +/- 0.5 (mean +/- standard deviation). Aortic systolic pressure (p less than 0.001) and left ventricular end-diastolic pressure decreased (10 +/- 3 to 8 +/- 3 mm Hg, p less than 0.01), and systemic vascular resistance decreased significantly (p less than 0.001), whereas pulmonary and right atrial pressure and pulmonary arteriolar resistance did not change. Cardiac and stroke indexes showed biphasic changes. Although positive and negative maximal rate of left ventricular pressures decreased significantly (p less than 0.05 and p less than 0.01, respectively), they did not change significantly when aortic systolic pressure was corrected. There was a significant inverse correlation between the negative rate of left ventricular pressure/aortic systolic pressure before nicardipine infusion and its maximal percent increase after infusion (r = -0.56, p less than 0.05), indicating a beneficial effect on diastolic relaxation in patients with impaired diastolic function. Our data show that a low dose (10 micrograms/kg) of intravenous nicardipine exerts a favorable effect on impaired diastolic function, but depresses left ventricular pump function with much less effect on right heart circulation.

Adult↗
PubMed1991

Comparative efficacy of acid reflux inhibition by drug therapy in reflux esophagitis.

The advent of histamine H2 receptor antagonists (H2-RA) has allowed the treatment of reflux esophagitis (RE) to be controlled over a relatively long term. The authors have experienced some cases resistant to H2-RA, but it was revealed that these cases can be successfully treated with proton pump inhibitors. It has been suggested that esophagogastric dysmotility can lead to RE. RE has been treated for many years by using GI-prokinetic agents, which theoretically inhibit acid reflux and improve esophageal acid clearance. In order to compare the effects on acid reflux of an H2-RA (famotidine), a proton pump inhibitor (omeprazole) and a GI-prokinetic agent (cisapride), we measured the 24-hour pH in the esophagus and stomach simultaneously, before and after treatment in 17 patients with RE. It was found that the proton pump inhibitor was the most effective drug for inhibiting esophageal acidification, followed by famotidine and then cisapride. Furthermore, we found that cisapride often actually exacerbated acid reflux. The differences in inhibitory effects on acidification allowed us to draw conclusions regarding the treatment of RE. It was concluded that the stronger the inhibitory effect of a drug on acid secretion, the more useful it was in the treatment of RE. The GI-prokinetic drug did not inhibit acid reflux as much as we had expected.

Adult↗
PubMed1991

Effects of famotidine on upper gastrointestinal motility in patients with progressive systemic sclerosis.

The effects of famotidine on human upper gastrointestinal motility were investigated, together with the relationship of gastric alkalinization and serum gastrin levels to changes produced by famotidine. Intravenous famotidine (20 mg), at a dose level in which an inhibitory effect on acetylcholinesterase activity is not recognized, was given to 13 patients with progressive systemic sclerosis but no other disorders. Gastric phasic motor activity was not changed significantly, but the lower esophageal sphincter pressure was elevated significantly in comparison with 15 controls given physiological saline, even when gastric phasic motor activity was taken into consideration. Gastric alkalinization with 7% sodium bicarbonate did not significantly increase the sphincter pressure in all 7 subjects so treated. No significant correlation was recognized between the serum gastrin level, the lower esophageal sphincter pressure, and the gastric motility index in any of the 3 groups. It was, therefore, concluded that intravenous administration of famotidine affected upper gastrointestinal motility, especially the lower esophageal sphincter pressure, through an as yet unknown mechanism other than inhibition of acetylcholinesterase activity, gastric alkalinization, or elevation of serum gastrin levels.

Adult↗
PubMed1991

The human CCG1 gene, essential for progression of the G1 phase, encodes a 210-kilodalton nuclear DNA-binding protein.

The human CCG1 gene complements tsBN462, a temperature-sensitive G1 mutant of the BHK21 cell line. The previously cloned cDNA turned out to be a truncated form of the actual CCG1 cDNA. The newly cloned CCG1 cDNA was 6.0 kb and encoded a protein with a molecular mass of 210 kDa. Using an antibody to a predicted peptide from the CCG1 protein, a protein with a molecular mass of over 200 kDa was identified in human, monkey, and hamster cell lines. In the newly defined C-terminal region, an acidic domain was found. It contained four consensus target sequences for casein kinase II and was phosphorylated by this enzyme in vitro. However, this C-terminal region was not required to complement tsBN462 mutation since the region encoding the C-terminal part was frequently missing in complemented clones derived by DNA-mediated gene transfer. CCG1 contains a sequence similar to the putative DNA-binding domain of HMG1 in addition to the previously detected amino acid sequences common in nuclear proteins, such as a proline cluster and a nuclear translocation signal. Consistent with these predictions, CCG1 was present in nuclei, possessed DNA-binding activity, and was eluted with similar concentrations of salt, 0.3 to 0.4 M NaCl either from isolated nuclei or from a DNA-cellulose column.

Amino Acid Sequence↗
PubMed1991

Molecular cloning of the human gene, CCG2, that complements the BHK-derived temperature-sensitive cell cycle mutant tsBN63: identity of CCG2 with the human X chromosomal SCAR/RPS4X gene.

A temperature-sensitive mutant tsBN63 cell line was isolated by the fluorodeoxyuridine method from the BHK21/13 cell line after mutagenesis with nitrosoguanidine. When cultures of tsBN63 cells growing asynchronously at 33.5 degrees C were shifted to 39.5 degrees C, a nonpermissive temperature, the ability for protein synthesis was rapidly reduced and cell proliferation stopped mainly at G1 phase, and partly at G2 phase. Synchronized cultures of tsBN63 cells did not commence DNA synthesis when shifted up in G1 phase. The human gene complementing the tsBN63 mutation was cloned by DNA-mediated gene transfer and its cDNA of 1.1 kb conferring ts+ phenotype on tsBN63 cells was isolated from the cDNA library of Raj (mer+) cells with a frequency of 10(-3). On the basis of the determined nucleotide sequence, the isolated human gene turned out to be the X chromosomal RPS4X encoding the ribosomal protein S4. The size of the CCG2 gene was estimated to be about 12 kb by complementation analysis of the tsBN63 mutation with cloned genomic DNA.

Amino Acid Sequence↗
PubMed1991

[Interdigestive migrating complex (IMC) and effect of cisapride in patients with non-ulcer dyspepsia (NUD)].

The 24-hr gastric and duodenal pressure measurement was performed in 5 patients with non-ulcer dyspepsia (NUD). The reduction of incidence of IMC and prolongation of the first appearance of IMC after evening meal were observed in NUD patients. The gastroprokinetic agent, cisapride 5 mg, 3 times a day for 7 days significantly increased the incidence of IMC and shortened the time before the first appearance of IMC after evening meal. This result indicates that in NUD patients impaired gastrointestinal motility is present in fasting phases and cisapride may be useful for correcting motility disorders.

Aged↗
PubMed1991

[Clinical studies on cefpirome in pediatrics].

Cefpirome (CPR, HR 810) was given intravenously to 10 children with acute bacterial infections including 8 with acute pneumonia, 1 each with acute pleuritis and urinary tract infections. Good to excellent clinical responses were obtained in all of the 10 patients and bacterial eradication were obtained for all 8 strains found in these cases. Slight elevation of GOT, GPT and eosinophilia were observed in 1 case each. From the above clinical results, it appears that CPR is a useful antibiotic for treatment of pediatric patients with various bacterial infections.

Adolescent↗
PubMed1990

The relationship between interdigestive gallbladder and gastroduodenal motility in man.

The relationship between interdigestive gallbladder and gastroduodenal motility simultaneously with the behavior of plasma motilin and CCK levels in 20 subjects was investigated. We used an infusion catheter method for the measurement of gastroduodenal motility, and real-time ultrasonography for the measurement of gallbladder size. In gastric phase II, the gallbladder contracted with extension of the major axis and shrinking of the minor axis, with its minimum volume being 84% of the volume in phase I. The gallbladder then filled rapidly assuming a sphere-like shape with extension of the minor axis and shrinking of the major axis in gastric phase I. This motility was recognized only during the gastrointestinal interdigestive migrating complex (GI-IMC) cycle, originating in the stomach, and was associated with an increase of motilin levels, it was not seen before or after the intestinal IMC (I-IMC), which originated in the duodenum without contraction of the stomach or an increase of motilin levels. Furthermore no apparent relationship was recognized between CCK and gastric or gallbladder motility. Our findings suggest that gallbladder motility in the interdigestive period has a close relationship with gastroduodenal motility and is related to the appearance of the GI-IMC.

Adult↗
PubMed1990

Protein engineering for thermostability.

Studies with small, monomeric proteins indicate that, to some extent, the effects of amino acid substitutions can be predicted. However, conformational and other changes may complicate the prediction. Site-directed mutagenesis is leading both to a better understanding of protein stability and to the production of more stable proteins.

Amino Acid Sequence↗