Biomedical subjects

H Takagi

Publications and source records attributed to H Takagi.

At least 271 records · Page 15Linked to original sources

PubMed1998

A gonadotropin-releasing hormone analogue impairs glucose tolerance in a diabetic patient.

Changes in serum glucose levels were examined in a female with insulin-independent diabetes who received a gonadotropin-releasing hormone (GnRH) analog treatment for pelvic endometriosis. The mean blood glucose levels were higher on busereline therapy, and higher levels of hemoglobin A1c were noted on busereline therapy (range 6.9-12.5%) versus pre- and post-treatment (range 5.1-5.9%). Hormonal alteration induced by GnRH analog treatment may impair glucose tolerance.

Adult↗

PubMed1998

Drastic elevation of serum CA125, CA72-4 and CA19-9 levels during menses in a patient with probable endometriosis.

Levels of CA125, CA72-4 and CA19-9, serum markers for ovarian cancer, were measured throughout menstrual cycles in a patient with probable pelvic endometriosis. The patient had CA125 levels >1000 U ml(-1), CA72-4>10 U ml(-1) and CA19-9>150 U ml(-1) during but not after menses (P<0.01). In luteal phase and premenstrual phase, the levels of these markers seemed to return normal ranges, although CA125 remained over the upper normal limit. Knowledge that a physiological elevation of these markers may occur during menses might avoid misinterpretation.

Adnexal Diseases↗

PubMed1998

Identification of estrogen-modified nucleosides from calf thymus DNA reacted with 6-hydroxyestrogen 6-sulfates.

Two estrogen sulfates, pyridinium 3-methoxyestra-1,3, 5(10)-trien-6alpha-yl sulfate (3MeE-6alpha-S) and its 6beta-isomer (3MeE-6beta-S), synthesized as model compounds to demonstrate the carcinogenesis of estrogen, were found to react with calf thymus DNA to produce steroid-modified DNA adducts. Digestion of the DNA by nuclease P1 and phosphodiesterase I followed by alkaline phosphatase gave a deoxyribonucleoside fraction, of which N2-[3-methoxyestra-1,3, 5(10)-trien-6alpha-yl]deoxyguanosine, N2-[3-methoxyestra-1,3, 5(10)-trien-6beta-yl]deoxyguanosine, N6-[3-methoxyestra-1,3, 5(10)-trien-6beta-yl]deoxyadenosine, and N6-[3-methoxyestra-1,3, 5(10)-trien-6alpha-yl]deoxyadenosine (identified as a base adduct) were identified using HPLC by comparing them with authentic specimens prepared by reacting dG and dA with both sulfates. No steroid-dC adduct was detected in the digestion products of the DNA adduct, although dC reacted with the sulfates to form N4-[3-methoxyestra-1,3,5(10)-trien-6beta-yl]deoxycytidine. These results mean that estrogen 6-sulfate has an ability to modify DNA via the amino group of a guanine or adenine residue in DNA. The present studies imply that a sequential metabolism (hydroxylation and sulfation) at the C6-position of the estrogen molecule causes damage to DNA.

Animals↗

PubMed1998

Porcine alpha-1,3-galactosyltransferase: full length cDNA cloning, genomic organization, and analysis of splicing variants.

Full length cDNA and genomic DNA of porcine alpha-1,3-galactosyltransferase were isolated, and their structures were analysed. The coding region was encoded by six exons as in the mouse, and the length of each exon was conserved between the two species. The porcine exons were designated Exon 4-9, since in the mouse coding exons started from Exon 4. Introns tended to be longer in the porcine gene; the distance from Exon 4 to the 3'-end of Exon 9 was 24 kb, while this region was 18 kb in the mouse gene. The cDNA structure was extended from the previous data to the 3'-end and to the 5' side of the cDNA. In addition to a cDNA clone with all coding exons, clones lacking parts of these exons were isolated and their structures were determined. One variant lacked Exon 5; the second, Exons 5 and 6; and the third, Exons 5, 6 and 7. The last variant was not found in the mouse, and cDNA transfection of this variant yielded scarcely any enzymatic activity using asialo alpha1-acid glycoprotein as a substrate, and decreased activity using N-acetyllactosamine as a substrate.

Amino Acid Sequence↗

PubMed1998

Establishment of complement-resistant retroviral vector by homologous restriction factor 20 gene.

Homologous restriction factor 20 (HRF20, CD59) is one of the complement regulatory factors. In this study, the complement-resistant retroviral vector, which possesses the HRF20 gene as a selection gene, was constructed and examined. The virus-producing cell, transduced with complement-resistant retroviral vector, was established after complement-dependent selection. NIH3T3 and PK15 cells transduced with this virus-producing cell were successfully selected by complement-dependent selection, which showed significant expression of the HRF20 antigen. In addition, these cells, transduced with tissue plasminogen activator (tPA) cDNA using complement-resistant retroviral vector, expressed tPA antigen after complement-dependent selection. These findings suggest that complement-resistant retroviral vector can be used for the double transduction of HRF20, as well as other genes.

3T3 Cells↗

PubMed1998

An increase of circulating leptin in patients with liver cirrhosis.

OBJECTIVE: Leptin, the ob gene product, is an anorexigenic peptide secreted from adipose tissue. However, the mechanism of leptin clearance/degradation has not been well determined in humans. The present study was undertaken to examine a possible involvement of liver in determining circulating leptin concentrations in humans. SUBJECTS: In the present study 58 healthy control subjects and 68 patients with liver cirrhosis (LC) without any renal dysfunction were randomly included. METHOD: The serum immunoreactive leptin (IRL) concentrations relative to the body mass index (BMI) were determined. Serum IRL and estradiol (E2) concentrations were assayed by radioimmunoassay (RIA). RESULTS: The correlations between the BMI and circulating IRL concentrations were all significant in male healthy controls (M-C), male patients with LC (M-LC), female healthy controls (F-C) and female patients with LC (F-LC). Circulating IRL concentrations were significantly higher than control in F-LC but not M-LC groups. The ratio of circulating IRL concentrations to the BMI was significantly higher in the M-LC group than in the M-C group and also significantly higher in the F-LC group than in the F-C group. The correlation between the IRL/BMI ratio and serum total bilirubin concentrations was significant (r = 0.417, P < 0.05) in the M-LC group, but not in the F-LC group. There was no significant correlation of the IRL/BMI ratio to serum E2 or albumin concentrations in either M-LC or F-LC groups. CONCLUSION: The present data demonstrated that the rate of increase in circulating IRL concentrations with the BMI was higher in LC patients of both genders. Liver may play a role in determining circulating leptin levels.

Aged↗

PubMed1998

Effects of local administration of osteocalcin on experimental tooth movement.

The purpose of this study was to evaluate the effects of local administration of osteocalcin, a major noncollagenous bone matrix protein, on experimental tooth movement in rats. An orthodontic elastic band was inserted between the upper first and second molars, and the first molar was moved mesially. Purified osteocalcin (0 to 10 micrograms) in 20 microliters of phosphate-buffered saline was injected into the region of the root bifurcation of the first molar daily for 4 days. Tooth movement increased significantly following the injections. Histological studies revealed that the injections markedly stimulated the appearance of osteoclasts on the pressured side of the alveolar bone surface. The results suggest that osteocalcin has an additive effect on the rate of orthodontic tooth movement through the enhancement of osteoclastogenesis on the pressured side.

Alveolar Process↗

PubMed1998

Effect on colon cancer cells of human interferon-beta gene entrapped in cationic multilamellar liposomes.

When cultured cells of human colon cancer cell line SW480 were transfected with human interferon-beta (hIFN-beta) gene by means of cationic multilamellar liposomes, the endogenously produced hIFN-beta exhibited a remarkable anti-proliferative effect on the cells, which was more effective than that of exogenously added hIFN-beta. This effect lasted for several days, and was blocked completely by the addition of sufficient amounts of anti-hIFN-beta antibody. From experiments using a transwell plate and an infusion pump, we found that endogenously produced hIFN-beta acted effectively on the cells around the transfectants and that the growth-inhibitory effect was totally retained upon continuous dilution of the medium. These data indicate that hIFN-beta expressed endogenously by transfer of its gene acted on these cancer cells mainly in a paracrine manner. Although the transfection with hIFN-gamma gene also revealed a definite growth-inhibitory effect on the same tumor cells, the extent was less than that of hIFN-beta gene.

Antibodies↗

PubMed1998

Undifferentiated pancreatic cancer associated with humoral hypercalcemia of malignancy.

We present a case of undifferentiated pancreatic cancer associated with humoral hypercalcemia of malignancy (HHM) in which parathyroid hormone-related protein (PTH-rP) is identified as the causative factor of hypercalcemia. A 61-year-old man was hospitalized with right hypochondralgia. Ultrasound examination and computed tomography demonstrated a large mass in the pancreatic head with liver metastases. Biopsy of the pancreatic tumor demonstrated undifferentiated carcinoma. Serum calcium level and PTH-rP were elevated. Bone scan with technetium-99 demonstrated no accumulation in the bones. Immunohistochemical staining for PTH-rP was weakly positive in the tumor cells. We considered that PTH-rP was the causative factor of HHM in this case from laboratory data and immunohistochemical findings. This rare case was successfully treated with pamidronate disodium, which is a type of bisphosphonate derivative. We compared this case with previously reported cases.

Antineoplastic Agents↗

PubMed1998

Cloning of the gene encoding a protochlorophyllide reductase: the physiological significance of the co-existence of light-dependent and -independent protochlorophyllide reduction systems in the cyanobacterium Plectonema boryanum.

Cyanobacteria have two protochlorophyllide (Pchlide) reductases catalyzing the conversion of Pchlide to chlorophyllide, a key step in the biosynthetic pathway of chlorophylls (Chls); a light-dependent (LPOR) and a light-independent (DPOR) reductase. We found an open reading frame (ORF322) in a 2,131-bp EcoRI fragment from the genomic DNA of the cyanobacterium Plectonema boryanum. Because the deduced amino acid sequence showed a high similarity to those of various plant LPORs and the LPOR activity was detected in the soluble fraction of Escherichia coli cells over-expressing the ORF322 protein, ORF322 was defined as the por gene encoding LPOR in P. boryanum. A por-disrupted mutant, YFP12, was isolated by targeted mutagenesis to investigate the physiological importance of LPOR. YFP12 grew as well as wild type under low light conditions (10-25 muE m-2 s-1). However, its growth was significantly retarded as a result of a significant decrease in its Chl content under higher light conditions (85-130 muE m-2 s-1). Furthermore, YFP12 stopped growing and suffered from photobleaching under the highest light intensity (170 muE m-2 s-1). In contrast, a chlL-disrupted (DPOR-less) mutant YFC2 grew as well as wild type irrespective of light intensity. From these phenotypic characteristics, we concluded that, although both LPOR and DPOR contribute to Chl synthesis in the cells growing in the light, the extent of the contribution by LPOR increases with increasing light intensity; without it, the cells are unable to grow under light intensities of more than 130 muE m-2 s-1.

Amino Acid Sequence↗

PubMed1998

Random mutagenesis into the conserved Gly154 of subtilisin E: isolation and characterization of the revertant enzymes.

We analyzed the role played by the conserved Gly154, a constituent of the P1 substrate-binding pocket of Bacillus subtilis subtilisin E, in the catalytic properties of the protease. Using an Escherichia coli expression system, the termination codon at position 154 in subtilisin E was first introduced to abolish the catalytic activity through truncation of the C-terminus from amino acid residues 154-275. We then attempted to obtain revertants with substitutions of various amino acids at position 154 by the polymerase chain reaction using a mixture of oligonucleotides. In addition to the Gly residue (wild-type), six amino acid substitutions (Ala, Arg, Leu, Phe, Pro and Thr) gave caseinolytic activity. When assayed with synthetic peptide substrates, most of the revertants showed a considerable decrease in specific activity and a P1 specificity similar to that of the wild-type enzyme. An Ala154 mutant purified from the periplasmic space in E. coli, however, resulted in an up to 2.3-fold preference for Val rather than Pro as a P2 substrate relative to the wild-type. Further, a significant 2-10-fold increase in the catalytic efficiency occurred in the Gly127Ala plus Gly154Ala combination variant, relative to the single Gly127Ala variant, without any change in the restricted specificity. The kinetic data and molecular modeling analysis demonstrate the important role of position 154 in the catalytic efficiency as well as in the substrate specificity of subtilisin E.

Amino Acid Sequence↗

PubMed1998

Engineering subtilisin YaB: restriction of substrate specificity by the substitution of Gly124 and Gly151 with Ala.

The 3-D structure of subtilisin YaB was computer modelled using the structures of subtilisin BPN', subtilisin Carlsberg and thermitase as templates. Gly124 and Gly151 located on both sides of the waist of the S1 pocket were selected for site-directed mutagenesis based on the modelled structure. The mutated ale genes coding for the mutant subtilisin YaB were expressed in Bacillus subtilis DB104. All of the G124 and G151 series of mutants exhibited an increase of relative catalytic activity for elastin-orcein against casein and myofibrillar proteins. The S1 substrate specificity of G124A, G124V and G151A mutants were assessed using various carbobenzoxy-amino acid-nitrophenyl esters and succinyl-Ala-Ala-(Pro or Val)-(Ala, Phe or Leu)-p-nitroanilide [AA(P/V) (A/F/L)]. While G124A and G124V mutants hydrolyzed only Ala and Gly esters, G151A mutant hydrolyzed Ala, Leu and Gly esters. The G124A and G124V mutants did not hydrolyze AAPF and AAPL. However, these two mutants hydrolyzed AAPA and AAVA with kcat/Km values approximately 3-10-fold higher than those of the wild-type enzyme. The G151A mutant did not hydrolyze AAPF, but hydrolyzed AAPL, AAPA and AAVA with kcat/Km values approximately 1-4-fold higher than those of the wild-type enzyme. These results clearly indicate that the S1 substrate specificity of G124A and G124V mutants was restricted to Ala and Gly, and G151A mutant to Ala, Gly and Leu.

Alanine↗

PubMed1998

Immunohistochemical and molecular biological studies of serous cystadenoma of the pancreas.

Seven cases of pancreatic serous cystadenoma were examined immunohistochemically and molecular biologically. Six were benign tumors and one was clinically malignant. Immunohistochemical studies were performed with the avidin-biotin peroxidase complex technique on paraffin-embedded tumor tissue and were stained with antibody to carcinoembryonic antigen (CEA), CA19-9, and p53 protein. Two-stage polymerase chain reaction-restriction fragment length polymorphism analysis was used to detect K-ras oncogene mutation at codon 12. No tumor cells were stained with anti-CEA and anti-p53 protein, but two cases were stained focally with anti-CA19-9. One case was benign and one was clinically malignant. In the anti-CA19-9 staining, tumor cells of the benign case were positive only on the apical membrane and supranuclear cytoplasm of the cells, whereas those of the clinically malignant case were positive over the entire surface and cytoplasm of the cells. All seven cases were without K-ras gene mutation. So the features of serous cystadenoma of the pancreas suggest a tumor genesis different from that of ductal adenocarcinoma. They also suggest a relationship between immunohistochemical localizations of CA19-9 in the tumor cells and the biological behavior of the tumor itself.

Adult↗

PubMed1998

Quantitative analysis of foveal retinal thickness in diabetic retinopathy with the scanning retinal thickness analyzer.

PURPOSE: This study sought to measure foveal retinal thickness in patients with diabetic retinopathy and to investigate the relationship between foveal thickness and visual acuity, biomicroscopic findings, and angiographic features. METHODS: A commercial scanning retinal thickness analyzer was used to measure retinal thickness. A laser slit was projected onto the retina and scanned in 400 milliseconds across the central area of the fundus. The image where the laser slit intersects with the retina was digitally recorded and analyzed. Retinal thickness was measured in 35 patients (35 eyes; patient age, 57 +/- 13 years) with diabetic retinopathy. Patients also were examined by fluorescein angiography and slit-lamp biomicroscopy to detect foveal thickening. RESULTS: Linear regression analysis indicated a significant correlation between foveal thickness and visual acuity (adjusted R2 = 0.72, P < 0.001). Foveal thickness was abnormal in 6 (100%) of 6 eyes in which foveal thickening was detected with slit-lamp biomicroscopy. Foveal thickness also was abnormal in 9 (31%) of 29 eyes that appeared normal by biomicroscopic examination. Foveal thickness was 136 +/- 65 microns in 7 eyes without leakage, 175 +/- 35 microns in 13 eyes with questionable leakage, and 291 +/- 120 microns in 7 eyes with definite leakage (P = 0.0075). CONCLUSIONS: Retinal thickness analysis is shown to be more sensitive than slit-lamp biomicroscopy for detecting small changes in retinal thickness. Retinal thickness analysis may prove to be a useful, noninvasive modality for the development or regression of macular edema.

Adult↗

PubMed1998

Tumor-specific activation of mitogen-activated protein kinase in human colorectal and gastric carcinoma tissues.

To search for the signaling events in colorectal carcinoma relevant to its tumorigenesis, we investigated the activity of mitogen-activated protein kinase (MAPK) in human colorectal carcinoma tissues and paired normal tissues. Of 64 cases examined, approximately 75% (48 cases) showed tumor-specific activation of MAPK by in situ kinase renaturation assay, as well as in vitro kinase assay with immunoprecipitated MAPK. In addition, tumor-specific activation of MAPK was associated with the activation of MAPK kinase in the cases we examined. However, no clear correlation of MAPK activation with lymph node involvement, metastatic rate, stage, histological classification, age or sex was observed. These results suggest that the MAPK pathway is involved in colorectal tumor development, but its activation alone is not sufficient for malignant conversion. In contrast to colorectal carcinoma, gastric carcinoma tissues showed a lower rate of MAPK activation, suggesting that the signaling pathway activated in colorectal carcinoma tissues may differ in part from that of gastric carcinoma.

Adult↗

PubMed1998

Accidental transmission of HCV and treatment with interferon.

Accidental transmission of contagious pathogens, especially hepatitis C virus (HCV), by needlestick or other means as an occupational hazard for medical staff is of concern. We retrospectively analysed cases of work-related accidental injury with pathogens such as hepatitis B virus (HBV), HCV, syphilis and human immunodeficiency virus (HIV) reported to the centres for disease control at 15 hospitals (total 5776 beds) in the Gunma prefecture, Japan, from December 1990 to August 1993 (24.7 months). There were 416 such cases (16.8 cases/month), with an incidence of 0.2-3.5 accidents per month per hospital. Such accidents occurred in 297 (71.2%) nurses, 98 (23.5%) medical doctors, 13 (3%) laboratory technicians, four (1.0%) hospital maintenance workers, one (0.2%) assistant nurse, one secretary and two others. There were 323 (77.6%) injuries caused by needlestick, 42 (10.1%) from suture needles or surgical knife cuts, 17 (4.1%) from blood splatters from patients into the eyes or mouth, 10 (2.4%) from contact with injured skin and 24 (5.8%) simple skin contacts. Of the pathogens, 60.3% were HCV, 22.6% HBV, 5.8% syphilis, 0.7% HIV and 10.6% were of unknown origin. Four cases (1.6%) of HCV infection were found and treated with one or two courses of interferon therapy, and HCV was subsequently cleared. All four patients were cured with interferon therapy. None of the HBV-injured cases resulted in infection, possibly because of prophylaxis with HB immunoglobulin and HB vaccine. No HIV or syphilis infection was contracted. In summary, chronic HCV infection acquired as an occupational hazard can be cured by appropriate treatment, such as with interferon, after early detection of the infection.

Accidents, Occupational↗

PubMed1998

Immunological features of patients with primary biliary cirrhosis (PBC) overlapping systemic sclerosis: a comparison with patients with PBC alone.

To characterize the immunological features of patients with primary biliary cirrhosis (PBC) overlapping systemic sclerosis (SSc), 26 patients with PBC were classified according to the presence of scleroderma-related features (Raynaud's phenomenon, sclerodactyly etc.). The patients were classified into 10 patients with PBC overlapping SSc (PBC-SSc), four patients with some scleroderma-related features although not meeting the criteria of SSc (PBC-SSc spectrum) and 12 patients with PBC alone. Sera from PBC-SSc showed a significantly higher positivity to anti-centromere antibody (P< 0.01) and to E1beta of pyruvate dehydrogenase complex (P< 0.005) than those from patients with PBC alone. The same tendency was observed in PBC-SSc spectrum patients. Patients with PBC exhibiting scleroderma-related features, in both the PBC-SSc and PBC-SSc spectrum, may comprise a subset in PBC, not only clinically, but also immunologically.

Adult↗

PubMed1998

Hepatic hydrothorax in the absence of ascites.

Pleural effusion due to hepatic cirrhosis and ascites is well known, but hepatic hydrothorax in the absence of ascites is a rare complication. We report a case of liver cirrhosis due to hepatitis C virus with a large and recurring pleural effusion that had an apparent abdominal source in the absence of ascites. We review the characteristics and treatment for hepatic hydrothorax in the absence of ascites.

Adult↗