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Biomedical subjects

J Watanabe

Publications and source records attributed to J Watanabe.

At least 235 records · Page 13Linked to original sources
PubMed1994

A small pedunculated adenomatous polyp of the colon found to contain the focus of invasive carcinoma extending to the serosa: report of a case.

A small pedunculated polyp was detected among other polyps in the transverse colon of a 64-year-old man, the resected specimen of which showed an adenomatous polyp 1 cm in diameter, containing the foci of adenocarcinoma invading the submucosa, muscularis, and serosa. This case report stresses the importance of performing careful pathologic examination of resected specimens obtained from endoscopic polypectomy, even for small pedunculated colon polyps.

Adenocarcinoma↗
PubMed1994

Absence of paravascular nerve projection and cross-innervation in interscapular brown adipose tissues of mice.

To determine whether a paravascular nerve projection or cross-innervation exists in the interscapular brown adipose tissue (BAT), the distribution of noradrenergic or peptidergic nerve fibers in intact or denervated interscapular BAT pads of mice was examined histochemically. Noradrenaline (NA) fibers were visualized by the glyoxylic acid condensation method, and neuropeptide Y (NPY) and substance P (SP) fibers were detected immunohistochemically. Numerous NA-positive fibers and a few NPY- or SP-positive fibers were observed around intralobular arterioles in intact BAT pads. Some NA-positive fibers and very few NPY- or SP-positive fibers were seen around interlobular arteries. NA- and NPY-positive fibers were also found around brown adipose cells in the parenchyme of BAT, whereas SP-positive fibers were absent around the cells. However, all sections cut from denervated BAT pads of unilaterally or bilaterally denervated animals showed a total absence of NA-, NPY- or SP-positive nerve fibers. Therefore, neither a paravascular projection of NA, NPY, and SP fibers to the BAT nor a cross-innervation of these nerve fibers between the left and right BAT pads exists in the mouse BAT.

Adipose Tissue, Brown↗
PubMed1994

Establishing a physical map of chromosome No. 4 of Plasmodium falciparum.

We isolated a panel of 20 DNA probes that hybridize specifically to chromosome No. 4 of Plasmodium falciparum and used them to construct a restriction map of chromosome No. 4 in the FCR3 strain. These probes were partially sequenced and had an insert size range of 70-310 bp (average 160 bp) and a GC content range of 19-53% (average 35%). Three probes were identical to previously described P. falciparum sequences. Two probes were homologous to an 18-bp repetitive sequence in a previously cloned P. falciparum gene but were not homologous to other parts of the gene. One probe sequence is a homologue of the heat shock protein, DnaJ. The location of these probes and four previously cloned probes on chromosome No. 4 were determined by using eight restriction enzymes that recognize 6-bp sites containing only G or C and 10 restriction enzymes that recognize 6-bp sites containing four G or C and two A or T. The locations of the probes were well distributed along the chromosome. Three probes were located at two sites and two probes were found at at least four sites on chromosome No. 4. Maps of chromosome No. 4 of the FCR3 strain, and three laboratory-selected, pyrimethamine-resistant derivative strains were constructed. Two of the strains, FCR3-D81 and FCR3-D85, each had two polymorphic forms of chromosome No. 4. Each of those polymorphic chromosomes had a duplicated part of the center of the chromosome making the cell diploid for the genetic material in that region. Those chromosomes also had an amplification and probable intrachromosomal translocation of a 50-kb fragment of chromosome No. 4. One strain derived from FCR3-D7, FCR3-D7-1 contained 20 copies of a tandemly amplified fragment carrying the dihydrofolate reductase-thymidylate synthase gene and an amplification of an unrelated part of the chromosome.

Animals↗
PubMed1994

Age-related changes in fibre number, fibre size, fibre type composition and adenosine triphosphatase activity in rat soleus muscle.

To study the aging of muscle fibres in red skeletal muscle, fibre number, fibre diameter and fibre type composition in the soleus muscle of male rats of 3, 12 and 24 months old were examined. The total number of muscle fibres remained unchanged, while average diameter increased slightly with increasing age. The staining intensity of myosin adenosine triphosphatase (ATPase) activity in the fibres decreased with advancing age. Therefore, observation on the basis of myosin ATPase histochemistry alone is not adequate to study the aging of muscle fibres. In the muscles of 24 month-old animals, four fibre types were recognized; 1) many (52%) type I-O fibres showing weak ATPase and succinate dehydrogenase (SDH) reactions with slight subsarcolemmal aggregates of diformazan (SAD); 2) some (33%) type M fibres showing weak ATPase and intense SDH reactions with marked SAD; 3) a few (12%) type O fibres showing weak ATPase and intense SDH reactions without SAD; and 4) very few (4%) type IIA fibres. Histochemical and morphometric results suggest that type I-O, type M and type O fibres are derived from type I, type I and type IIA fibres, respectively. Furthermore, no transitional fibres from type IIA to type I were observed. Therefore, age-related changes in fibre type composition in the muscle cannot be explained by the simple idea that most type IIA fibres are transformed into type I fibres.

Aging↗
PubMed1994

Interindividual difference in expression of human Ah receptor and related P450 genes.

The genomic clones of human aryl hydrocarbon receptor (Ahr) and Ahr nuclear translocator (Arnt) were isolated, and the structures of exon-intron junctions of these genes were partially determined. Based on the sequence information, a quantitative RT-PCR analysis was developed, and the expression of these genes was studied in various human tissues. mRNAs for Ahr and Arnt were widely expressed in human tissues and abundantly in lung. Individual difference in expression levels of Ahr and Arnt mRNA was observed in liver, lung and blood. In order to examine whether expression levels of Ahr and Arnt were associated with those of CYP1A1, we studied the expression of these mRNAs in blood among 20 healthy subjects, taking account of individuals' cigarette smoking habits. We found that the expression levels of CYP1A1 appeared to associate with those of Ahr and Arnt mRNAs (P < 0.06), and also that the expression of Ahr and Arnt was influenced by cigarette smoking. The expression of human Ahr and Arnt is reported here for the first time, providing a quantitative RT-PCR analysis as a useful tool for further studies.

Adult↗
PubMed1994

Effects of ryanodine on development of myogenic response in rat small skeletal muscle arteries.

OBJECTIVE: The aim was to elucidate the functional role of the sarcoplasmic reticulum in myogenic contraction. METHODS: Small arteries which perfuse the rat gracilis muscle were isolated and cannulated. The inner diameter was measured under no flow condition. Myogenic contraction was induced by increasing transmural pressure from 40 to 100 mm Hg. The diameter transient and the steady state internal diameter were analysed at 40 (ID40) and 100 mm Hg (ID100) of lumen pressure. RESULTS: In control, the vessels dilated immediately after the pressure change, and then constricted over approximately 4 min (the diameter decay). ID40 and ID100 were 120(SEM 16) and 108(12) microns (n = 6, p < 0.05), respectively. Ryanodine (10(-5) M) decreased ID40 to 82(8) microns. The relative rate of the diameter decay in the first 1 min was lower in the ryanodine treated vessels than in control, at 43(1)% v 74(7)%, n = 6 (p < 0.05). While KCl constriction was similar to that of ryanodine, the diameter decay was identical to that of control. Thus a decrease in baseline diameter was not of itself the cause of the depressed rate of diameter decay in the ryanodine treated vessels. Nisoldipine (10(-6) M) abolished myogenic contraction. CONCLUSIONS: Ryanodine sensitive sarcoplasmic reticular function is probably involved in the mechanism for developing the myogenic response in rat skeletal muscle small arteries.

Animals↗
PubMed1994

Different regulation and expression of the human CYP2E1 gene due to the RsaI polymorphism in the 5'-flanking region.

The effects of two genetically associated polymorphisms [c1 allele: PstI -, RsaI +; c2 allele: PstI +, RsaI -] in the 5'-flanking region on the regulation and expression of the human CYP2E1 gene were investigated. DNase I footprinting and CAT activity analyses using various deletion mutants constructed with DNA segments from genotype A (c1/c1) or C (c2/c2) and SV40 or an endogenous promoter showed that the RsaI polymorphism affects the binding of a transcription factor and the transcriptional activation of CYP2E1, while the PstI polymorphism has little effect. The correlation between the genotypes and expression levels of CYP2E1 mRNA were examined in peripheral lymphocytes of 86 individuals by RT-PCR, the alcohol consumption by the subjects being taken into account. In non-drinkers, the mean ratio of the expression of CYP2E1 mRNA to that of GAPDH mRNA in genotype B (c1/c2) was 1.7-fold higher than that in genotype A (0.05 < p < 0.10). As compared to non-drinkers with genotype A, subjects with genotype B who drank alcohol on a daily basis expressed about 2.0-fold higher levels of CYP2E1 mRNA (p < 0.01). These results indicate that a RsaI polymorphism in the 5'-flanking region of CYP2E1 may lead to inter-individual differences in CYP2E1-mediated microsomal drug oxidation activities, including oxidation of N-nitrosamines.

Alleles↗
PubMed1994

Markers of hepatitis C and B virus infections among blood donors in Ho Chi Minh City and Hanoi, Vietnam.

Blood donors in two cities in Vietnam were tested for markers of hepatitis C virus (HCV) and hepatitis B virus infections. Antibody to HCV was detected by passive hemagglutination with antigens of the second generation in 101 (20.6%) of 491 donors in Ho Chi Minh City; it was detected less frequently (P < 0.001) in donors in hanoi (4 [0.8%] of 499). HCV RNA was tested for in donors with antibody by PCR with nested primers from the 5'-noncoding region and detected in 79 donors in Ho Chi Minh City and 4 donors in Hanoi. HCV RNA was genotyped by PCR with type-specific primers from the core gene. Of 83 HCV carriers from Vietnam, 24 (29%) were infected with HCV of genotype I/1a 19 (23%) were infected with II/1b, 4 (5%) were infected with III/2a, and 2 (2%) were infected with mixed genotypes (I/1a and II/1b); HCV genotypes in the remaining 34 (41%) donors, including all 4 donors in Hanoi, were not classifiable into I/1a, II/2a, IV/2b, or V/3a. Of the 10 isolates with unclassifiable genotypes, 2 showed substantial sequence divergence within the 5'-noncoding region from reported isolates with known genotypes (I/1a to 6a). An analysis of part of the core gene sequence indicated that six of the remaining isolates most likely represented new HCV genotypes. Hepatitis B surface antigen and the corresponding antibody, respectively, were detected in 15 (3.1%) and 234 (47.7%) donors in Ho Chi Minh City as well as 15 (3.0%) and 248 (49.7%) donors in Hanoi. These results indicate an extensive spread of HCV among Ho Chi Minh City donors and HCV of novel genotypes in vietnam.

Adult↗
PubMed1994

Measurement of NADPH-cytochrome P-450 reductase content in rat liver sections by quantitative immunohistochemistry with a video image processor.

We have a quantitative light microscopic immunohistochemical method using video image processing. First, an antigen (NADPH-cytochrome P-450 reductase) content in homogenates of livers of rats was measured by enzyme immunoassay. Then frozen sections from rat livers were incubated with the anti-NADPH-cytochrome P-450 reductase antibody under saturation conditions by the indirect immunoperoxidase method. Subsequently, relative staining intensities in small portions and those in wide areas in the sections were measured with a video image processor. Finally, the resulting relative values obtained from the small portions were converted into absolute NADPH-cytochrome P-450 reductase contents using the results of enzyme immunoassay and the average relative staining intensity obtained from the wide areas in the sections. The reductase content in sections from rat livers measured by the image processing method coincided with the content measured by the microphotometric method using a nitrocellulose model system. The present image processing method is applicable to measurement of contents of antigens that can not be immobilized in model systems.

Animals↗
PubMed1994

Gastric emptying-limited oral absorption of alpha-linolenic acid administered as a milk fat-globule membrane (MFGM) emulsion in rats.

As a study to assess the potential application of milk fat-globule membrane (MFGM), which is of natural origin and expected to be a safer alternative to synthetic emulsifiers, to pharmaceutical dosage forms, the oral absorption of alpha-linolenic acid was evaluated by the analysis of gastrointestinal disposition after oral administration as an MFGM emulsion to rats. A linear model incorporated with first-order gastric emptying followed by first-order intestinal absorption was fitted to the data of the remaining fraction of alpha-linolenic acid versus time profiles for the stomach and small intestine to estimate the rate constants of gastric emptying (kg) and intestinal absorption (ka). The ka (0.045 min-1) was about 4 times larger than the kg (0.011 min-1). The kg was comparable to the apparent oral absorption rate constant estimated by the pharmacokinetic analysis of plasma concentration data. These results suggest that the oral absorption of alpha-linolenic acid administered as MFGM emulsion is gastric emptying-limited and, hence, any change in the intestinal absorption process would only modestly affect its oral absorption.

Animals↗
PubMed1994

Influence of urethane anesthesia and abdominal surgery on gastrointestinal motility in rats.

The influence of various experimental treatments on propulsive gastrointestinal motility was examined in rats, using inulin as a marker. In unanesthetized rats without any surgery, the distribution center of inulin, which was expressed as a dimensionless distance normalized by the length of the small intestine, reached 0.587 down the intestinal tract from the pylorus 60 min after the intragastric administration of inulin. However, the distribution center of inulin moved only 0.061 in 60 min in unanesthetized rats with minimial abdominal surgery for intraduodenal administration of inulin, and did not move in unanesthetized rats with cannulas for perfusion or in the rats anesthetized with urethane and treated with abdominal surgery. In urethane-anesthetized rats without surgery, almost 100% of the inulin was recovered from the stomach 60 min after intragastric administration. These results suggest that gastrointestinal motility is extensively suppressed by minimal abdominal surgery as well as by anesthesia.

Abdomen↗
PubMed1994

The inhibitory effects of tea polyphenols (flavan-3-ol derivatives) on Cu2+ mediated oxidative modification of low density lipoprotein.

Tea polyphenols (flavan-3-ol derivatives) suppressed the oxidative modification of low density lipoprotein (LDL) which is assumed to be an important step in the pathogenesis of atherosclerosis lesions. Inhibitory experiments on the oxidative impairment of porcine serum LDL by flavan-3-ols were carried out by incubating them at 37 degrees C in the presence of 5 microM Cu2+. The oxidation of LDL was monitored either by an absorption increase at 234 nm due to the conjugated diene formation, or the formation of hydroperoxides and thiobarbituric acid reactive substances (TBARS). It was found that the oxidation was strongly inhibited by various flavan-3-ols, and a lag time over 100 min appeared, depending on the types of flavan-3-ols used. The activities based on the prolongation of the lag time were in the order of (-)-epigallocatechin (EGC) < (+)-catechin (C) < (-)-epicatechin (EC) < (-)-epicatechingallate (ECG) < (-)-epigallocatechingallate (EGCG). IC50 of flavan-3-ols on Cu2+ mediated hydroperoxides and TBARS formation of LDL were 0.90, 0.95 microM for ECG and 2.38, 2.74 microM for EGC, respectively. It was found that the Cu2+ mediated cholesterol ester degradation in LDL was almost completely inhibited by 5.0 microM C or EGCG. Cu2+ mediated apolipoprotein B-100 fragmentation was also inhibited (up to 60%) in the presence of C or EGCG.

Animals↗
PubMed1994

Inter-organ relation between salivary gland and kidney in lithium excretion. IV. Saturation of inhibitory effect of NaCl on ductal reabsorption of Li+ in beagle dogs.

The inhibitory effect of NaCl coadministration on the reabsorption of Li+ in the salivary ducts and the renal tubules was investigated in beagle dogs. Following the bolus intravenous administration of LiCl (0.145 meq/kg), 50 ml of NaCl solution (100, 200 meq/l) was administered orally each hour, and parotid saliva (Pr) and mandibular-sublingual saliva (MS) were collected under the continuous stimulation of salivation with citric acid. The renal clearance of Li+ increased with the increased concentration of administered NaCl solution. This could be a result of the competitive inhibition of the tubular reabsorption of Li+ by Na+. The salivary clearance of Li+ also tended to increase by the administration of NaCl. These results suggest the existence of a reabsorption process of Li+ in the salivary glands similar to that in the renal tubule. However, when the administered NaCl was increased from 100 to 200 meq/l, the renal clearance was further increased, but the salivary clearance was not. This suggests that the transport capacity of Li+ reabsorption is relatively small in the salivary glands, compared with that in the renal tubule, and that the inhibitory effect of NaCl on Li+ reabsorption had already reached a maximum level when 100 meq/l NaCl was administered.

Absorption↗
PubMed1994

Evaluation of milk fat-globule membrane (MFGM) emulsion for oral administration: absorption of alpha-linolenic acid in rats and the effect of emulsion droplet size.

The performance of milk fat-globule membrane (MFGM) emulsion as an oral dosage form was evaluated in rats using [14C]alpha-linolenic acid as a lipophilic model solute. For emulsions prepared by homogenization alone, the area under the plasma concentration versus time curve (AUC) after oral administration tended to be larger for MFGM emulsion, 35.0 +/- 2.5 micrograms eq.h/ml (mean +/- S.E., n = 3), than for Tween 80 emulsion, 28.5 +/- 0.6 micrograms eq.h/ml at p < 0.1, though the peak plasma concentration (Cmax) and the time required to reach Cmax (Tmax) were not significantly different. The absorption in the intestinal loop was not significantly different between the two emulsions, either. Thus, MFGM emulsion, compared with Tween 80 emulsion, did not show an obvious advantage or enhancement in the oral and intestinal absorption of alpha-linolenic acid, except for a slight increase in AUC. However, MFGM could be a good alternative to a synthetic emulsifier for oral use, considering that it is of natural origin and may be safer. In addition, it was shown that the AUC, as well as the absorption in the intestinal loop, was decreased for a MFGM emulsion in which the droplet size was reduced by sonication, presumably because of the observed decrease in alpha-linolenic acid concentration in the water phase, which was assumed to be the result of an increased distribution of alpha-linolenic acid, due to its amphipathic nature, to the increased oil-water interface.

Administration, Oral↗
PubMed1994

Enhancing effect of 4-hydroxy-3-nitrophenylacetic acid on transcription of the ice nucleation-active gene of Xanthomonas campestris.

Cultivation of an ice nucleation-active strain of Xanthomonas campestris in the presence (1 ppm) of 4-hydroxy-3-nitrophenylacetic acid resulted in enhancement of its ice-nucleation activity. Both the ice-nucleation-active protein, InaX, and its mRNA were effectively expressed in the bacterial cells cultured in the presence of this compound. This indicates that this compound stimulated the biosynthesis of the ice-nucleation-active protein.

Bacterial Proteins↗