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Biomedical subjects

T Seki

Publications and source records attributed to T Seki.

At least 829 records · Page 46Linked to original sources
PubMedDate not supplied

Expression of basic fibroblast growth factor in hyperplastic parathyroid glands from patients with multiple endocrine neoplasia type I.

Primary hyperparathyroidism was investigated using the presence of basic fibroblast growth factor (bFGF) from the immunohistochemical viewpoint with an anti-bFGF antibody in hyperplastic parathyroid glands of patients with multiple endocrine neoplasia type I (MEN-I) and of patients with non-MEN. The results corresponded well with the data from the DNA analysis. Twenty-five hyperplastic parathyroid glands from 11 patients with MEN-I and 38 glands from 20 patients with non-MEN primary hyperparathyroidism were stained immunohistochemically according to the avidin-biotin-peroxidase complex procedure. When 50% or more of the cells appeared uniformly stained, it was judged positively stained. In addition, 18 hyperplastic parathyroid glands from patients with MEN-I patients and 24 hyperplastic parathyroid glands from non-MEN patients were also analyzed for DNA using flow cytometry. The ratio of positively stained hyperplastic parathyroid glands was 72% in MEN-I patients and 18% in non-MEN patients. The difference between the two groups was significant (p < 0.01). The nodules consisted of oxyphilic cells in 7 of 25 hyperplastic parathyroid glands from MEN-I patients and in 10 of 38 hyperplastic parathyroid glands from non-MEN patients, and all the cells were positive for bFGF. There was no significant correlation between bFGF staining and the DNA ploidy pattern. bFGF possibly plays a role in the development of parathyroid gland hyperplasia, especially in MEN-I patients. The increase of oxyphilic cells may be correlated with the expression of bFGF.

Fibroblast Growth Factor 2↗
PubMedDate not supplied

The 'double cortex' syndrome on MRI.

We report a 6-year-old girl with diffuse subcortical heterotopia (band heterotopia), an unusual type of ectopic gray matter on magnetic resonance imaging (MRI). Her cerebral parenchyma had four layers consisting of cortex, thin outer white matter, diffuse subcortical heterotopia, and inner white matter around the lateral ventricles, giving the appearance of a 'double cortex'. The overlying cortex had midly broad gyri, especially in the frontal lobes. MRI showed the appearance of laminar heterotopia, a classical pathological entity. The double cortex syndrome is presumably a radiological delineation of laminar heterotopia. Her development was slightly delayed and she was clumsy and easily upset, with poor impulse control. However, her daily life was largely unaffected in spite of the severe abnormalities on MRI. She had abnormal movements during sleep, and sleeping EEG showed high voltage spindles in the bilateral frontal areas but no epileptic discharges. It could not be determined whether or not these movements were epileptic. The double cortex syndrome, an anomaly of the central nervous system associated with mental retardation, epilepsy, behavioral problems, and exclusive occurrence in girls, will be established as a clinico-radiological entity.

Brain Diseases↗
PubMedDate not supplied

Magnetic resonance signal intensity ratio of gray/white matter in children. Quantitative assessment in developing brain.

Magnetic resonance imaging (MRI) findings in 87 children with various clinical entities were used to determine the signal intensity ratio of gray/white matter in T1- and T2-weighted images using a 1.5 T MR Scanner. Signal intensity ratio changes in both T1- and T2-weighted images correlated well with advancing age (y = 0.9349-0.001575, r = -0.584, P < 0.0001 in T1-weighted images; y = 0.9798 + 0.002854, r = 0.723, P < 0.0001 in T2-weighted images), but the correlation was more linear when we included only normally developed (34) children (y = 0.9689-0.001967, r = -0.654, P < 0.0001 in T1-weighted images; y = 0.9882 + 0.002965, r = 0.747, P < 0.0001 in T2-weighted images). Abnormal ratios were observed in patients with congenital hydrocephalus, inherited metabolic diseases and cerebral palsy. Although the gray/white matter differentiation would not delineate the myelination itself, measurement of the signal intensity ratio of gray/white matter is a practical way to evaluate delayed myelination in a busy MR center.

Adolescent↗
PubMedDate not supplied

Practical guidelines for physicians in the management of febrile seizures.

Recent studies have shown that adequate medication can prevent the recurrence of febrile seizures (FS). It has also been clarified that the vast majority of, though not all, FS patients follow a benign course. Then, questions arise as to whether or not FS should be prevented, particularly in light of the risks of side effects from drugs. Which kinds of FS can be prevented, if necessary? The guidelines presented here are aimed primarily at helping general practitioners in considering how to manage FS most appropriately. The guidelines stress that judgements should be individualized, while referring to a few specific 'warning factors'. The guidelines follow a 'laissez-faire' principle for the majority of FS cases, whereas intermittent therapy with diazepam and continuous medication with either phenobarbital or valproate are indicated in other limited cases meeting respective definite criteria.

Humans↗
PubMedDate not supplied

Structural organization of the rat thy-1 gene.

Thy-1 is a differentiation marker expressed predominantly on thymocytes, T cells and brain tissue. Its presence on murine peripheral T cells but not B cells has long been used to distinguish between these two populations of lymphocytes. Although analogues of Thy-1 have been described in several mammalian species, its tissue distribution in different species varies widely, precluding its use as T-cell-specific marker. The Thy-1 molecule is a cell-surface glycoprotein of relative molecular mass 18,000, one-third of which represents carbohydrate; the protein moieties of the rat and murine Thy-1 molecules have been sequenced and found to consist of 111 and 112 amino acids, respectively. An unusual aspect of Thy-1 is the apparent absence of a hydrophobic segment comparable to that observed in other membrane glycoproteins which would allow integration of Thy-1 within the membrane lipid bilayer. This has prompted speculation that Thy-1 is anchored to the cell surface by some other hydrophobic component such as glycolipid. Here we report the structure of thy-1 complementary DNA and genomic clones and describe the exon-intron organization of the gene. More importantly, our data indicate that Thy-1 is initially synthesized as a molecule of 142 amino acids, 31 amino acids longer at the carboxyl end than the Thy-1 molecule isolated and characterized by Campbell et al. An extremely hydrophobic region of 20 amino acids lies within this 31-amino acid stretch and may represent the transmembrane segment responsible for anchoring Thy-1 to the cell membrane.

Amino Acid Sequence↗
PubMedDate not supplied

Prostaglandin synthesis inhibitor improves hypotension during normothermic cardiopulmonary bypass.

Hypotension is a major systemic side effect during cardiopu monary bypass (CPB), especially at normothermia. We previously reported that prostaglandin (PG) might play a substantial role in hypotension. The purpose of this study was to clarify whether a PG synthesis inhibitor (PGSI) could improve hypotension during CPB. Thirty-six patients undergoing cardiac surgery with normothermic CPB (35-37 degrees C) were divided into two groups: a PGSI group (n = 18), whose members wer given a PGSI before and during CPB, and a control group (n = 18). In both groups, perfusion flow was sufficient and pressure was maintained at above 45 mm Hg by infusion of metaraminol, a vasoconstrictor. The mean arterial pressure throughout CPB was significantly higher in the PGSI group than in the control group (57 +/- 4 vs. 48 +/- 3 mm Hg, p < 0.01), whereas the dose of infused metaraminol was significantly lower in the PGSI group (13 +/- 7 vs. 21 +/- 6 mg, p < 0.01). The blood base excess was not significantly different (1.0 +/- 1.6 vs. 1.7 +/- 1.9 mmol/L, p = 0.28), and urine output was significantly higher in the PGSI group (503 +/- 179 vs. 354 +/- 112 ml/hr, p < 0.01). In conclusion, PGSI can improve hypotension during CPB and increase urine output without impairing peripheral circulation.

Aged↗
PubMedDate not supplied

CT evaluation of invasive trophoblastic disease.

We report the use of dynamic CT for the evaluation of trophoblastic disease of the uterus. In five cases showing evidence of persistent trophoblastic disease after evacuation of a molar gestation, contrast enhancement of the myometrium demonstrated several hypodense foci surrounded by highly enhanced areas. These observations were not found in two cases of successfully evacuated hydatidiform mole without sequela. A case of choriocarcinoma showed a large central nonenhanced lesion with peripheral contrast enhancement. Filling defects in a markedly contrast enhanced lesion probably represent hydatids penetrating the myometrium and should suggest invasive mole.

Adult↗
PubMedDate not supplied

MR imaging of peripheral cholangiocarcinoma.

A prospective study was performed to compare MR spin-echo (SE) sequences [repetition time/echo time (TR/TE) 2,000/80, 500/44 ms], unenhanced CT, and rapid intravenous contrast enhanced CT in eight consecutive patients with peripheral cholangiocarcinoma. All the tumors (ranging from 5 to 9.6 cm in size) were detected with all four techniques. Tumor contrast, however, was qualitatively greatest on long TR/TE SE images. With long TR/TE SE images, tumors were demonstrated as well-demarcated homogeneous regions of high signal intensity, and the anatomic relations between tumors and intrahepatic blood vessels were easily perceived. Detection of small intrahepatic metastatic foci was best on long TR/TE images. Tumor invasion of the portal vein's branches was also best seen on long TR/TE SE images. These results indicate that long TR/TE SE sequence is the most effective initial screening method in demonstrating the presence and determining resectability of peripheral cholangiocarcinoma.

Adenoma, Bile Duct↗
PubMedDate not supplied

Liver metastases from colon cancer with intra-bile duct tumor growth: radiologic features.

PURPOSE: Our goal was to characterize the radiologic features of liver metastases from colon cancer with intrahepatic bile duct (IHBD) dilatation. METHOD: Radiologic findings of liver metastases from colon cancer with IHBD dilatation of four patients were compared with pathologic findings. RESULTS: The cause of bile duct dilatation in all cases was due to papillary tumor growth in the bile duct. In two patients, intra-bile duct tumor growth (IBDTG) was observed on imaging. In the other two patients, IBDTG was not observed, but a nontapered abrupt obstruction of a dilated bile duct was seen, corresponding to the microscopically proven papillary tumor growth in the ductal lumen. In three patients who underwent an extensive hepatic resection, there has been no recurrence. In one patient who had a nonanatomic limited resection, a recurrence was seen 1 year after surgery. CONCLUSION: When liver tumor with IBDTG is suspected on imaging, liver metastases should be considered in the differential diagnosis besides hepatocellular carcinoma or cholangiocellular carcinoma. Careful preoperative assessment for IBDTG by imaging is essential to determine the extent of surgical resection.

Aged↗
PubMedDate not supplied

Low prevalence of hepatitis C virus infection in patients with auto-immune hepatitis type 1.

Hepatitis C virus (HCV) antibodies were measured in 28 patients with auto-immune hepatitis type 1 using six different assay kits, three for C100-3 antibody and three for second generation HCV antibody, and two confirmatory tests to determine the prevalence of HCV infection in auto-immune hepatitis. These patients were confirmed to have human leucocyte antigen DR 4 or 2 which is susceptible to auto-immune hepatitis in Japanese. Of the 28 patients, four (14.3%) were positive for HCV antibody in all assays and reacted positively in at least one of the two confirmatory tests, indicating a true positive finding. Eight were positive for HCV antibody only by the Ortho ELISA kit and were negative in both confirmatory tests. The cut-off level for these results was low and became negative soon after the patients received corticosteroid treatment. Thus, these eight patients are presumed to be false-positive reactors. Hepatitis C virus RNA was detected in the serum of two of the four patients with HCV antibody and in none of 24 patients without HCV antibody. No significant difference was observed between the patients with and without HCV antibody in terms of clinical background, liver function tests and auto-antibodies. Our results showed that the prevalence of a past or present HCV infection in patients with auto-immune hepatitis in Japan is low; thus, auto-immune hepatitis is thought to be distinct from hepatitis type C. However, it is also suggested that HCV infection can potentially trigger auto-immune hepatitis.

Adult↗
PubMedDate not supplied

Intracellular application of calmidazolium increases Ca2+ current through activation of protein kinase A in cultured vascular smooth muscle cells.

In the present study, we investigated the actions of calmodulin (CaM) and CaM-dependent protein kinase II (CaMK-II) on the L-type Ca2+ currents (ICa(L)) of cultured vascular smooth muscle (VSM) cells (A7r5 cell line), using the whole-cell voltage clamp method. The peak IBa (Ca2+ channel using 5 mM Ba2+ as charge carrier) was evoked every 15 s by a test potential to +10 mV from a holding potential of -60 mV. To test the effect of CaM on IBa, 1 microM calmidazolium (CMZ), an inhibitor of CaM, was added to the pipette solution (pCa of 6.5 or 300 nM [Ca]i). The amplitude of maximally activated IBa was -4.3 +/- 0.5 pA/pF (n = 13) for control and -8.1 +/- 0.9 pA/pF (n = 14) in the presence of CMZ. This difference was statistically significant (p = 0.016). The CMZ stimulation of IBa was not abolished when 5 microM KN-62, a specific inhibitor of CaMK-II, was included in the pipette (-9.5 +/- 1.1 pA/pF; n = 10). Introduction of CaMK-II itself intracellularly had no effect on the basal IBa. On the other hand, the CMZ stimulation of IBa was prevented by both H-7, a nonspecific protein kinase inhibitor, and H-89, a specific inhibitor of protein kinase A (PK-A). Since CMZ is a strong inhibitor of Ca2+/CaM-dependent phosphodiesterase (type I PDE), we studied the effect of 8-methoxymethyl-3-isobutyl-1-methylxanthine (MIBMX), another specific inhibitor of the PDE. MIBMX, like CMZ, stimulated IBa: control, -4.6 +/- 0.4 pA/pF (n = 10); MIBMX, -9.6 +/- 1.2 (n = 8), and CMZ, -7.9 +/- 0.9 (n = 15). 0.1 mM 8Br-cAMP, a membrane permeable cAMP analogue, stimulated IBa by +42%: before, -3.7 +/- 0. 7 pA/pF; after, -5.2 +/- 1.0 (n = 6). In conclusion, Ca2+ channels of VSM cells might not be directly regulated by the CaM/CaMK-II pathway. Therefore, the CMZ stimulation of IBa might occur due to the increase in intracellular concentration of cAMP produced by inhibition of CaM-dependent PDE.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗