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Biomedical subjects

T Yamagami

Publications and source records attributed to T Yamagami.

At least 55 records · Page 3Linked to original sources
PubMed2000

Trace analysis of pesticide residues in water by high-speed narrow-bore capillary gas chromatography-mass spectrometry with programmable temperature vaporizer.

A method for the rapid trace analysis of 17 residual pesticides in water by narrow-bore capillary (I.D. 100 microm) gas chromatography-mass spectrometry (GC-MS) using a programmable temperature vaporizer (PTV) was discussed. The method consisted of a large-volume injection (40 microl) by a PTV, high-speed analysis using a narrow-bore capillary column and MS detection. The PTV with solvent vent mode was very useful for large-volume injection into a narrow-bore capillary column because the injected solvent volume could be reduced to less than 2 microl. The analysis time was 8.5 min [less than 50% of the analysis time using conventional columns (I.D. 250 microm)]. A 10-ml volume of river water was extracted by dichloromethane (4 ml), and then the extract was condensed to 1 ml. This extract was analyzed. Mean recoveries for river water spiked at 100 pg/ml ranged from 83.4 to 96.7%. The limit of detections of the 17 pesticides ranged from 1 to 100 pg/ml.

Gas Chromatography-Mass Spectrometry↗
PubMed2000

Reference data of forearm bone mineral density in healthy Japanese male and female subjects in the second decade based on calendar age and puberty onset: Japanese Population Based Osteoporosis (JPOS) study.

Osteoporosis is a major public health problem in Japan. The second decade is an important period in which to attain a high peak bone mass. However, normal values of forearm bone mineral density (BMD) are not well known in children and adolescents. BMD at one-third of forearm length proximal to the ulnar end plate (BMD1/3) and the ultradistal forearm (BMDud) was measured using dual-energy X-ray absorptiometry (DXA) in 1207 (631 males, 576 females) Japanese subjects aged 9-18 years. Puberty onset was assessed by questionnaire, by obtaining the time that pubic hair appeared in males and the time that menstruation started in females. BMD1/3 and BMDud increased steadily with age in males. In relation to puberty development, these parameters also increased after puberty onset although the increase in BMD1/3 was not statistically significant after the fifth year from puberty onset and that of BMDud was not significant after the sixth year from puberty onset. BMD1/3 and BMDud increased with age and then plateaued in females. The increase in BMD1/3 was not statistically significant after 15-16 years of age and that of BMDud was not significant after 13-14 years of age. In relation to puberty development, the increase in BMD1/3 leveled out after the fourth year from puberty onset and that of BMDud also plateaued after the third year from puberty onset. We provide reference values of forearm BMD in Japanese children and adolescents by DXA according to calendar age and puberty development. Peak bone mass of the forearm may be in the late second decade in Japanese females.

Absorptiometry, Photon↗
PubMed2000

Intrahepatic portosystemic venous shunt associated with biliary atresia: case report.

We describe an infant with intrahepatic portosystemic venous shunt (IPSVS), which was detected by MR angiography. IPSVS is rare and its cause is disputed. However, with improvements in imaging the number of reports of IPSVS identified incidentally in patients without definite symptoms is increasing. The present case is the first associated with congenital biliary atresia and the youngest reported in the literature.

Biliary Atresia↗
PubMed2000

Angiomyolipoma arising in the thigh.

A 41-year-old man presented with an asymptomatic mass in the right medial thigh. Magnetic resonance imaging (MRI) revealed a well-demarcated, 10-cm mass in the right adductor muscles. The margins of the mass exhibited high signal intensity and the rest showed low or iso signal intensity on T1-weighted MR images. However, the high signal intensity was decreased on T2-weighted images with fat suppression. The central part of the tumor was of inhomogeneous high signal intensity on T2-weighted images; after Gd-DTPA injection it enhanced in homogeneously on T1-weighted images with fat suppression. On dynamic computed tomography (CT) in the arterial phase, there were strongly enhancing spotty areas in the tumor. At surgery, a yellow-whitish tumor was resected and a pathological diagnosis of angiomyolipoma (AML) in the thigh was made.

Adipose Tissue↗
PubMed2000

[Probe types of Norwalk-like viruses genome detected by RT-PCR with seven primer pairs in Yamanashi Prefecture].

The reverse transcription-polymerase chain reaction (RT-PCR) gene assay, as well as electron microscopic examination, is commonly used to detect Norwalk-like viruses (NLVs). Types and number of primer pairs used are considered to be of critical importance for efficiency of the RT-PCR detection. This study was performed to determine primer pairs useful for the detection of NLVs. NLVs genes were detected by RT-PCR in 48 cases in Yamanashi Prefecture between December 1997 and March 2000. The probe type of the gene was G2P-C in 21, G2P-B in 10, G2P-A in 6, G1P-A in 3, G1P-B in 2, and a mixture of G2P-A and G2P-B in 6. The NLVs genes of G2P-C and G2P-B were estimated to have undergone mutation in the polymerase region and poorly specific to the primer pair 35/36, a combination that has been used most commonly for the RT-PCR assay in Japan. The primer pair G2R1/F1 that amplifies the capsid (CAP) region of NLVs genes can detect all NLVs genes of the Genogroup2. The combination of this primer pair with another primer pair G1R1/F1, which like G2R1/F1, amplifies the CAP region, makes discrimination between NLVs of different groups possible. Consequently, this combination, may be the most useful for the NLVs detection by RT-PCR.

DNA Primers↗
PubMed2000

The aetiology of non-tumorous enhancement in the hepatic hilum shown on CT hepatic arteriography.

The causes of non-tumorous abnormalities in the hepatic hilum seen on CT hepatic arteriography were investigated. 13 patients with non-tumorous defects of portal perfusion in the hepatic hilum on CT arterial portography underwent both CT hepatic arteriography from the common hepatic artery and CT obtained during proper hepatic arteriography. The findings of non-tumorous portal defects on these two angiographic studies using helical CT were compared. In the 13 patients, 14 non-tumorous defects of portal perfusion in the hepatic hilum on CT arterial portography were detected as enhanced areas in 10 regions (dorsum of segment IV, 7/10; dorsum of the lateral segment, 3/4) on CT hepatic arteriography via the common hepatic artery, but none were enhanced on CT obtained during proper hepatic arteriography. In conclusion, the main cause of non-tumorous enhancement in the hepatic hilum seen on CT hepatic arteriography is non-portal direct inflow via the parabiliary venous system.

Aged↗
PubMed2000

Increased hepatic arterial blood flow after decreased portal supply to the liver parenchyma owing to intrahepatic portosystemic venous shunt: angiographic demonstration using helical CT.

This study was conducted to investigate the haemodynamics of the liver parenchyma in the presence of intrahepatic portosystemic venous shunt. 3 patients with intrahepatic portosystemic venous shunts and 24 patients with normal intrahepatic haemodynamics underwent both CT arterial portography and CT during hepatic arteriography. Angiographic findings with helical CT were compared, and CT attenuated values were measured in both groups. The liver parenchyma on CT arterial portography had lower attenuation than on CT during hepatic arteriography in all patients with intrahepatic portosystemic venous shunts. Overall average CT attenuation was 92.2 +/- 7.7 Hounsfield units (HU) on CT arterial portography and 149.9 +/- 8.5 HU after CT during hepatic arteriography, with the opposite findings in all patients without intrahepatic portosystemic venous shunt: CT attenuation 142.0 +/- 25.7 HU on CT arterial portography and 100.7 +/- 16.4 HU after CT during hepatic arteriography. In conclusion, the portal venous supply to the liver parenchyma decreased due to intrahepatic portosystemic venous shunts, with a compensatory increase in hepatic arterial blood supply.

Adult↗
PubMed2000

Non-tumorous enhancement caused by cholecystic venous inflow shown on biphasic CT hepatic arteriography: comparison with hepatocellular carcinoma.

The haemodynamics in non-tumorous abnormalities on CT arterial portography (CTAP) owing to cholecystic venous direct inflow to the liver were compared with the haemodynamics in hepatocellular carcinoma. 53 patients who simultaneously underwent CTAP and CT during hepatic arteriography (CTHA) to detect hepatocellular carcinoma had the late phase added to CTHA. Changes in size, shape and pattern of 47 non-tumorous enhancement abnormalities on the liver around the gall bladder or in the dorsum of segment IV between the early and late phases on biphasic CTHA as well as of 60 tumorous lesions were determined. Enhancement on biphasic CTHA was seen in all 47 lesions with a non-tumorous portal defect (early phase alone, n=8; late phase alone, n = 3; both, n = 36). In these 47 lesions, the size and the shape of enhancement changed in 63.8% and 51.1%, respectively, between the early and late phases on CTHA; the pattern of enhancement did not change in 72.3%. On the other hand, the size of enhancement on biphasic CTHA changed in only 16.7% of 60 tumours, and the shape in only 5%, although the enhancement pattern changed in a large proportion (80%). In conclusion, owing to the difference in haemodynamics, non-tumorous abnormalities caused by cholecystic venous inflow and tumours are clearly delineated on biphasic CTHA. Thus, adding the late phase to previous single phase CTHA (i.e. performing biphasic CTHA) is useful in differentiating the two entities.

Aged↗
PubMed2000

Positions of disulfide bonds in rye (Secale cereale) seed chitinase-a.

The positions of disulfide bonds of rye seed chitinase-a (RSC-a) were identified by the isolation of disulfide-containing peptides produced with enzymatic and/or chemical cleavages of RSC-a, followed by sequencing them. An unequivocal assignment of disulfide bonds in this enzyme was as follows: Cys3-Cysl8, Cys12-Cys24, Cys15-Cys42, Cys17-Cys31, and Cys35-Cys39 in the chitin-binding domain (CB domain), Cys82-Cys144, Cys156-Cys164, and Cys282-Cys295 in the catalytic domain (Cat domain), and Cys263 was a free form.

Amino Acid Sequence↗
PubMed2000

Cloning, sequencing, and expression of the tulip bulb chitinase-1 cDNA.

A cDNA encoding tulip bulb chitinase-1 (TBC-1) was cloned using a combination of immunoscreening from a lambda ZAP cDNA library with anti-TBC-1 antiserum and the 5' rapid amplification of cDNA end (RACE) method, and sequenced. The cDNA consists of 1,106 nucleotides and included an open reading frame encoding a polypeptide of 314 amino acids. Comparison of the deduced amino acid sequence and the determined protein sequence indicated the presence of a signal peptide and an extra peptide composed of 26 and 13 amino acids at the N- and C-termini, respectively. The deduced sequence of TBC-1 had 10-20% and 63% sequence similarities to plant class III chitinases and gladiolus bulb class IIIb chitinase (GBC-a), respectively. The cDNA encoding mature TBC-1 was amplified by polymerase chain reaction (PCR), ligated into the expression vector pET-22b, and expressed in Escherichia coli BL21(DE3). The recombinant TBC-1 (rTBC-1) expressed in E. coli was purified by gel filtration followed by ion-exchange chromatography. Specific activity of the rTBC-1 was almost same as the authentic TBC-1 toward glycolchitin. This is the first report on the cDNA cloning of a class III chitinase having C-terminal extra peptide.

Amino Acid Sequence↗
PubMed2000

Calcification of the cervical ligamentum flavum--case report.

A 52-year-old male presented with calcification of the cervical ligamentum flavum manifesting as hypesthesia of the bilateral middle, ring, and little fingers and ulnar halves of both forearms, as well as motor weakness in the bilateral upper extremities and gait disturbance. Cervical x-ray tomography detected a round calcified mass on the posterior wall of the cervical canal at the C-5 level. Computed tomography showed the round, nodular calcified mass more clearly. Magnetic resonance imaging showed an epidural low intensity mass compressing and distorting the cervical cord at the C-5 level on both T1- and T2-weighted images. Administration of gadolinium-diethylenetriaminepenta-acetic acid caused marginal enhancement of the mass. The lesion was eventually removed by posterior laminectomy. The mass was composed of a very hard crystal-like calcified deposition in the ligamentum flavum. X-ray diffraction analysis of the histological specimen showed calcium pyrophosphate dihydrate (CPPD) and hydroxyapatite in the crystal-like substance, confirming that CPPD is responsible for calcification of the cervical ligamentum flavum.

Calcinosis↗
PubMed2000

Repertoire selection by pre-B-cell receptors and B-cell receptors, and genetic control of B-cell development from immature to mature B cells.

During B-cell development the surrogate light (SL) chain is selectively expressed in progenitor and precursor B cells during the developmental stages of D(H) to J(H) and V(H) to D(H)J(H) rearrangements. Approximately half of all muH chains produced by these rearrangements cannot pair with SL chains and cannot form a pre-B-cell receptor (pre-BCR). A spectrum of affinities between VpreB and individual V(H) domains generates preB cells with pre-BCR of different fitness which, in turn, determines the extent of the pre-B II-cell proliferation and the fidelity of allelic exclusion of the H chain locus. Once pre-BCR is expressed, SL chain expression is turned off. As pre-B II cells proliferate, SL is diluted out, thus limiting pre-BCR formation. As a consequence, pre-B II cells stop proliferating, become small and resting and begin to rearrange the L chain loci. Multiple rearrangements of the kappaL chain alleles are often detected in wild-type small pre-B II cells. Around 20% of the muH chain-expressing small pre-B II cells also express L chains but do not display the Ig on the surface. Hence, it is likely that not all L chains originally generated in resting pre-B II cells can pair with the muH chain previously present in that cell. The best fitting ones are selected preferentially to generate sIg+ B cells. Furthermore, the transition of immature B cells from the bone marrow to spleen and their development to mature cells appear as two separate steps controlled by different genes.

Alleles↗
PubMed2000

[Details and indications of pallidotomy and thalamotomy for Parkinson's disease].

Pallidotomy has recently regained acceptance as an effective treatment for Parkinson's disease. From our 50 cases of unilateral pallidotomy and 10 cases of staged bilateral pallidotomy, details and indications of the procedure is described. The unilateral pallidotomy is quite effective for L-dopa induced dyskinesia, which usually completely disappears soon after the operation. The effect is long-lasting. When on-off phenomenon exists, unilateral pallidotomy improves off-stage rigidity or akinesia. Symptoms during on-stage are not changed. Indications of pallidotomy is that(1) L-dopa induced dyskinesia, and(2) on-off phenomenon. Bilateral pallidotomy, even by staged one, causes severe drooling, or speech disturbance(the volume of the voice decreases and the articulation worsens), and is not recommended. Vim thalamotomy is, on the other hand, the established treatment for tremor of Parkinson's disease or of essential tremor. The effect is long-lasting. Rigidity or akinesia is not expected to be improved so much.

Dyskinesia, Drug-Induced↗
PubMed1999

Influence factors on the development of obesity in 3-year-old children based on the Toyama study.

BACKGROUND: Obesity in childhood increases the risk of obesity in adulthood. Obesity in adulthood is a risk factor for chronic diseases such as hypertension and atherosclerosis. Therefore, it is important to eliminate factors influencing the development of obesity in children from the viewpoint of preventive medicine. The purpose of this study is to elucidate the relationship between obesity and lifestyle in 3-year-old children in a case-control study. METHODS: Subjects were selected from the Toyama study at health checkups for 3-year-old children which are done routinely by local governments in Japan on all children of that age. A special questionnaire consisting of items on lifestyle and environmental factors of the children and past histories of parents was distributed to the Toyama study participants beforehand and was collected at the checkup. Matched-pair comparisons were performed between obese children whose body mass index was 18 or more (N = 427) and control children (N = 854) matched by sex and birth month. Multivariate stepwise conditional logistic regression analysis was also applied to assess the influence of confounding factors. RESULTS: The following six factors significantly influenced the development of obese 3-year-old children using the Mantel-Haenszel method: the mother's job, limited playtime outdoors (1 hour or less), snacking irregularity, an overweight father (body mass index >/= 24), an overweight mother (body mass index >/= 24), and overweight at birth (birth weight >/= 3,500 g). An overweight mother or father, limited playtime outdoors, overweight at birth, and snacking irregularity were significantly related to obesity in 3-year-old children after adjusting for confounding factors by multivariate stepwise conditional logistic regression analysis. CONCLUSIONS: We have suggested several factors influencing the development of obesity in 3-year-old Japanese children: parental overweight and overweight at birth as host factors, physical inactivity and snacking irregularity as behavioral factors, the mother's job as an environmental factor.

Body Mass Index↗
PubMed1999

The roles of preB and B cell receptors in the stepwise allelic exclusion of mouse IgH and L chain gene loci.

Membrane-bound preBCR of wild-type mice, and probably also preBCR-like V(preB) muH chain complexes in lambda5-deficient mice, signal allelic exclusion so that < 0.1% of all preB-II cells and all subsequent B lineage cells express two muH chains on their surface. On the other hand a large number of muH chains which are originally generated at the transition of preB-I to preB-II cells cannot pair with surrogate L chains, cannot form a preBCR on the surface and, hence, allow two H chain alleles to be productively rearranged in one B-lineage cell. By contrast membrane-bound BCR on immature B cells does not signal allelic or isotypic exclusion Of Ig kappaL and lambdaL chain gene loci. This allows the rearrangement machinery to remain active, and secondary L chain rearrangements on one kappaL chain allele are frequently observed. Rapid selection of fitting H/L chain pairs, forming BCR on the surface, allows B-lineage cells to enter the mature B cell pool where the rearrangement machinery is shut off, securing allelic exclusion of L chain loci in most B cells.

Alleles↗