Search PubMed⌕ Search

Biomedical subjects

H Shima

Publications and source records attributed to H Shima.

At least 91 records · Page 5Linked to original sources
PubMed1998

[AIDS among the Japanese-Brazilian residents of the Sao Paulo municipality: size and profile of the studied group].

The study aimed to know the spread of AIDS epidemic among Japanese and their descendents, living on São Paulo Municipality. The authors dimension the total number of cases, since the beginning of the epidemic till july, 1994 and characterized the profile of the group in terms of sex, age, school degree, civil status, sexual option, occupation, exposed category and mean survival.

Acquired Immunodeficiency Syndrome↗
PubMed1998

One additional mutation at exon A amplifies thermolability of androgen receptor in a case with complete androgen insensitivity syndrome.

We have previously demonstrated a substitutional mutation (glycine to alanine at position 820) of the androgen receptor (AR) gene in a patient with complete androgen insensitivity syndrome (CAIS). We first examined whether the mutation could lead to a disorder in AR binding activity in in vitro expression experiments. In a luciferase assay, the effect of the mutant AR on a target's gene was definitely impaired. However, the mutant AR had less thermal instability compared to that of the patient's fibroblast cell lines established in a whole-cell binding assay. In order to analyze the cause of the thermal instability, a further analysis of exon A in the AR gene was performed because the previous study had been performed only between exon B and H encoding the DNA-binding domain and the hormone-binding domain. The second mutation (leucine to proline at position 257) was newly identified. In in vitro expression experiments, the AR with both mutations showed marked thermal instability, whereas the AR with a mutation in exon A had no effect on thermal stability. The results show that the N-terminal domain might also play an important role in amplifying or modifying the AR binding activity.

Androgen-Insensitivity Syndrome↗
PubMed1998

Shortage of glutamine (CAG) homopolymeric repeats suppresses the expression of the androgen receptor in familial cases with complete androgen insensitivity syndrome.

The androgen receptor gene of two familial cases with complete androgen insensitivity syndrome was analyzed. The shortage of glutamine homopolymeric repeats (13 repeats) in the N-terminal domain of the androgen receptor of the patients was identified by DNA sequence analysis. In vitro transfection experiments with the patients' androgen receptor gene indicated that the expression of the androgen receptor in transfected COS-7 cells was decreased by 10% as compared to that of the wild type androgen receptor gene. The thermal stability of the 5 alpha-dihydrotestosterone-androgen receptor complex was also partially impaired. The capacity of the androgen receptor to activate target gene transcription was partially disturbed in a luciferase assay. The shortened glutamine homopolymeric repeats might therefore be related to the pathogenesis of complete androgen insensitivity syndrome.

Adult↗
PubMed1998

[Effect of the skull on brain perfusion SPECT imaging].

Because attenuation gradually decreases reconstructed counts from the periphery to the center portion of the object, the deep region far from the detector is not clearly observed if attenuation is not compensated. In brain perfusion SPECT, diagnosis is sometimes made using filtered back projection images without attenuation compensation (FBP). Brain perfusion SPECT has the unique characteristic that the radiopharmaceutical accumulates only within the brain and is never taken up by the surrounding skull. This study investigated the effect of skull on brain perfusion SPECT reconstructed with FBP. We theoretically derived the relation between the counts of brain and the linear attenuation coefficient of skull. It was found that the difference in reconstructed counts between the deep gray matter and peripheral gray matter decreased due to the existence of the skull. This result indicated that the deep gray matter was inclined to be visible if the FBP images were displayed according to relative counts normalized to the maximum count of each image. In order to confirm this, we made a numerical phantom with realistic human brain and skull contours on the basis of MR images from a normal volunteer. The linear attenuation coefficient of brain was assumed to be 0.15 cm-1, while that of skull was assumed to be 0.26 cm-1 (denoted as BONE+) or 0 cm-1 (BONE-). In accordance with the theoretical results, the deep gray matter of BONE+ images was more clearly observed than that of BONE- images, if these were displayed using the relative counts of each images. The physical phantom experiments also supported the theoretical and numerical phantom studies.

Cerebrovascular Circulation↗
PubMed1998

[Arterial infusion chemotherapy with SMANCS-Lipiodol for multiple hepatocellular carcinoma].

Fifty-five patients with hepatocellular carcinoma were treated with oily anticancer agent SMANCS dissolved in Lipiodol (SMANCS-LPD). The local response rate after the first arterial infusion in all patients was 39%, against 63% in 27 patients with Lipiodol accumulation occupying more than two thirds of tumor areas. The infusion therapy with SMANCS-LPD is adapted for a vascular-rich hepatocellular carcinoma. An infusion of 4 mg of SMANCS was ineffective for patients with tumors distributing in bilateral lobes of liver. Thus, an increase of infusion dosage or repeated infusions were recommended for such cases.

Aged↗
PubMed1998

[Breath-hold 3D MR urography with 2 ml Gd-DTPA injection].

Breath-hold gadolinium-enhanced 3D MR urography was performed in five healthy volunteers. Enhanced 3D fast gradient-echo with a spectral IR pulse sequence was used for depicting MR urography, which was obtained 5-10 minutes after the injection of 2 ml of gadopentate dimeglumine (0.013-0.02 mmol/kg). The urinary tract was depicted as a high-signal intensity area, and detectability of the non-dilated urinary tracts was superior to that of heavy T2-weighted images. At the same time, comparison between the urinary tract and vascular structure could be made using breath-hold contrast-enhanced 3D MR angiography with an additional Gd-DTPA injection.

Adult↗
PubMed1998

[MR cholangiopancreatography of pancreas divism and anomalous arrangement of the pancreaticobiliary ducts].

The purpose of this study was to evaluate the usefulness of MR cholangiopancreatography (MRCP) for pancreas divism and anomalous arrangement of pancreaticobiliary ducts (APBD). In 214 patients, MRCP was performed. In 204 patients (94%), pancreaticobiliary ductal junction could be recognized. Pancreas divism was observed in 13 of 204 patients (6%), and APBD was observed in 10 of 204 patients (5%). Dynamic MRCP after secretin stimulation was useful for diagnosing pancreas divism and APBD.

Bile Ducts↗
PubMed1998

[Combined scatter and attenuation correction for 201Tl myocardial perfusion SPECT using OS-EM algorithm].

There are two possible ways to obtain scatter-corrected images with the ML-EM (maximum likelihood expectation maximization) algorithm: one is the subtraction of scatter estimate si from projection data pi, and then (pi-si) is used for scatter-corrected projection data (denoted as SC(T)); the other method is the addition of scatter estimate si to the projections calculated from the reconstructed image without performing data subtraction (SC(E)). This paper investigated these two ML-EM algorithms of combined scatter and attenuation correction on 201Tl myocardial perfusion SPECT imaging. Scatter windows were placed one full width at half maximum (FWHM) below and above the photopeak centerline. The scatter fraction in the primary peak was estimated using trapezoidal approximation by the triple energy window method. Phantom and clinical images were reconstructed using 6 iterations of ordered subsets EM algorithm (OS-EM). A cylindrical phantom with a cold-rod insert and a heart/thorax phantom with liver insert were used to evaluate scatter and the attenuation compensation technique. A cylindrical phantom filled with uniform 201Tl solution was used to evaluate statistical noise. The percent root-mean-square uncertainty (%RMSU) was used as a quantitative measure of noise amplification. %RMSU showed that the SC(E) method amplified noise less in comparison with the SC(T) method, however, no significant difference in image quality was observed between the two methods. In conclusion, both the SC(T) and SC(E) methods provided significant and similar improvement in the removal of scatter in 201Tl myocardial perfusion SPECT imaging.

Absorption↗
PubMed1998

[Women and AIDS: profile of an infected population and its social implications].

This study aimed to identify the profile of women with AIDS from a Health Service located in São Paulo City, from October to December, 1995. The data obtained from medical charts allowed to characterize the profile in terms of age, school degree, marital status, occupation, exposed category and mean survival time. Besides, it was possible to know the number of children--sons and daughters of those women--that might be real or potential AIDS' orphans, an important social problem involving the phenomena. Authors discuss the women's particularities in the process of the disease and the social implications related to the spread of the infection in this group.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Induction of minisatellite mutation in NIH 3T3 cells by treatment with the tumor promoter okadaic acid.

Okadaic acid (OA) is a strong tumor promoter of mouse skin carcinogenesis and also a potent inhibitor of serine/threonine protein phosphatases. OA induces various genetic alterations in cultured cells, such as diphtheria-toxin-resistance mutations, sister chromatid exchange, exclusion of exogenous transforming oncogenes, and gene amplification. The present study revealed that it caused minisatellite mutation (MSM) at a high frequency in NIH 3T3 cells, although no microsatellite mutation was found. Nine of 31 clones (29%) exhibited MSM after 6 days of OA treatment, as opposed to only 1 of 30 clones (3%) without OA exposure. Moreover, NIH 3T3 cells treated with OA acquired tumorigenicity in nude mice, giving rise to 7 tumors within 25 weeks in 20 sites where 3 x 10(6) cells were injected. In contrast, the same numbers of untreated cells gave rise to only one tumor, and the tumor grew much slower. All of three OA-induced tumors examined manifested the MSM. The findings thus point to a molecular mechanism by which OA could function as a tumor promoter, and also the biological relevance of the induction of MSM in the tumorigenic process by OA.

3T3 Cells↗
PubMed1997

cDNA cloning of a novel B subunit of Xenopus protein phosphatase 2A and its biological activity in oocytes.

We have cloned a cDNA encoding a novel B regulatory subunit of protein phosphatase 2A (PP2A) from a Xenopus oocyte cDNA library. The novel B subunit, termed B beta', shows the strongest overall sequence similarity to, but a distinct N-terminal sequence from, the beta isoform of the human/rat B subunit. When expressed ectopically in Xenopus oocytes, the B beta' isoform can augment the endogenous PP2A activity and inhibit oocyte maturation induced by progesterone. These results suggest that the B beta' isoform can form a complex with other PP2A subunits to make a trimeric PP2A holoenzyme in Xenopus oocytes and may negatively control the initiation of oocyte maturation.

Amino Acid Sequence↗
PubMed1997

Esophageal metastasis from prostate cancer: diagnostic use of reverse transcriptase-polymerase chain reaction for prostate-specific antigen.

An extremely rare case of esophageal metastasis from prostate cancer is reported. A 65-year-old man presented with anorexia and back pain. Upper gastrointestinal X-ray fluoroscopy and endoscopy revealed a shallow longitudinal ulcer, with converging mucosal folds, approximately 5 cm above the esophagogastric junction. The histological diagnosis of the biopsied specimen was adenocarcinoma. Blood biochemistry revealed elevated serum prostate-specific antigen (PSA) and gamma-seminoprotein levels. Ultrasonography of the prostate disclosed a hypoechoic lesion in the left lobe, and needle biopsy led to the diagnosis of prostatic adenocarcinoma. Since there was no finding suggestive of a primary lesion, apart from that in the prostate, we conducted reverse transcriptase-polymerase chain reaction (RT-PCR) for PSA. PSA-positive mRNA was demonstrated in the tissue of the esophageal tumor. There are three reports on metastasis to the esophagus from prostate cancer, but this is the first case of esophageal metastasis from prostate cancer without any evidence of metastasis to other organs. The importance of RT-PCR for the diagnosis of primary lesions of metastatic cancer is discussed.

Adenocarcinoma↗
PubMed1997

Precision of the gallbladder ejection fraction obtained with Tc-99m-pyridoxyl-5-methyl-tryptophan (99mTc-PMT) hepatobiliary scintigraphy as compared with the contraction ratio in three-dimensional computed tomography.

UNLABELLED: The gallbladder ejection fraction (GBEF) obtained with Tc-99m-pyridoxyl-5-methyl-tryptophan (99mTc-PMT) hepatobiliary scintigraphy has been used as a parameter of gallbladder function. To determine the accuracy of GBEF, the relationship with the contraction ratio of the gallbladder (GBCR) obtained with three-dimensional helical computed tomography (3D-CT) was studied. PATIENTS AND METHODS: A normal volunteer, 8 patients suffering from cholecystolithiasis and a patient with gallbladder dyskinesia were examined. The percent initial dose (%ID) for the gallbladder and GBEF with hepatobiliary scintigraphy were used to compare the volume of the gallbladder and GBCR which was measured by 3D-CT. RESULTS: The %ID of the gallbladder was correlated with the volume of the gallbladder by 3D-CT (Y = 1.000X - 1.818, r = 0.928). GBEF was correlated well with GBCR by 3D-CT (Y = 0.916X + 6.296, r = 0.975). CONCLUSIONS: The %ID of the gallbladder obtained with hepatobiliary scintigraphy may be a good indicator of the volume of the gallbladder. The accuracy of GBEF was confirmed by comparison with 3D-CT examination. GBEF is considered a useful parameter of pathophysiological gallbladder function.

Adult↗
PubMed1997

Increased Ca2+ sensitivity of contractile elements via protein kinase C in alpha-toxin permeabilized SMA from young spontaneously hypertensive rats.

OBJECTIVE: The purpose of the present investigation was to examine the Ca2+ sensitivity of the contractile elements via protein kinase C (PKC) in superior mesenteric artery (SMA) from young (5-6 weeks old) spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). METHODS: Staphylococcal aureus alpha-toxin, which produces pores in the plasma membrane too small to allow passage of proteins such as PKC, was used to investigate the signal transduction system in vascular smooth muscle cells. We investigated the Ca2+ sensitivity of the contractile apparatus via PKC in intact and alpha-toxin skinned SMA from young SHR and WKY. RESULTS: In intact SMA, high K+ responses were not different between SHR and WKY. However, phorbol 12,13-dibutyrate (PDBu, a PKC activator) augmented high K(+)-evoked contractions and PKC inhibitors, such as 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7) and calphostin C, suppressed them more in SHR as compared with WKY. In alpha-toxin skinned SMA, the [Ca2+]i-force relationship curve was not significantly different between SHR and WKY. However, PDBu augmented [Ca2+]i-evoked contractions and PKC inhibitors suppressed them more in SHR than in WKY. CONCLUSION: These results suggest that the Ca2+ sensitivity of the contractile elements via PKC is significantly greater in prehypertensive SHR than in age-matched WKY. This abnormality in small muscular arteries may be involved in the pathogenesis of hypertension in SHR.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1997

Initial experience with non-breath-hold magnetic resonance cholangiopancreatography: a new noninvasive technique for the diagnosis of choledochal cyst in children.

BACKGROUND/PURPOSE: Magnetic resonance cholangiopancreatography (MRCP) is an emerging tool for the noninvasive evaluation of the pancreaticobiliary tree. METHODS: Non-breath-hold MRCP was used in three children to evaluate choledochal cyst; a first for this new modality of diagnostic imaging. In all cases, the intrahepatic and extrahepatic bile ducts, and the pancreatic duct were clearly visualized. RESULTS: Two cases were found to have a fusiform choledochal cyst, and non-breath-hold MRCP demonstrated pancreaticobiliary malunion and a long common channel. In the remaining case, the size and location of the huge cyst prevented visualization of any pancreaticobiliary malunion. Endoscopic retrograde cholangiopancreatography (ERCP) in this patient failed to provide any additional information. All patients underwent cyst excision with hepaticoenterostomy, and made an uneventful recovery. CONCLUSIONS: Our initial experience suggests that non-breath-hold MRCP is a reliable method for the diagnosis of choledochal cyst in children and could replace ERCP.

Age of Onset↗
PubMed1997

DNA analysis of the androgen receptor gene in two cases with complete androgen insensitivity syndrome.

OBJECTIVE: Androgen insensitivity syndrome is an X-linked disorder of sexual differentiation resulting from abnormalities of the androgen receptor gene. In this study, we analyzed the androgen receptor gene in 2 cases with complete androgen insensitivity syndrome (CAIS). METHODS: DNAs were isolated from patients with CAIS, and the androgen receptor gene was amplified by a polymerase chain reaction. Sequence analysis of the androgen receptor gene was performed. RESULTS: In Patient 1, one substitutional mutation [glutamine (CAA) to arginine (CGA) at position 194] was identified in exon A, and the premature termination of the androgen receptor gene was also demonstrated due to the deletion of one nucleotide at the codon in exon C (position 597). In Patient 2, one substitutional mutation [arginine (CGC) to cysteine (TGC) at position 855] in exon G was identified. This position was located in the hormone-binding domain and appeared to be a hot spot of mutations because the mutations at the same position have been reported before in several unrelated cases. CONCLUSION: The results of this study suggest that these abnormalities might be related to the pathogenesis of complete androgen insensitivity syndrome.

Adult↗
PubMed1997

[Detection of methicillin-resistant Staphylococcus aureus (MRSA)--relation between respiratory tract and gastro-intestinal tract].

The study was conducted to elucidate the possibility of hospital infection of methicillin-resistant Staphylococcus aureaus (MRSA) through feces. Fecal cultures of 12 inpatients positive for MRSA in the respiratory tract and 11 inpatients negative for MRSA in the respiratory tract were performed from April to October in 1993. Fecal cultures of inpatients positive for MRSA in the respiratory tract were continued until September in 1996, finally a total of 50 cases were enrolled. MRSA was isolated from feces of 7 patients (58.3%) of the 12 patients positive for MRSA in the respiratory tract, while no MRSA was isolated from feces of 11 patients negative for MRSA in the respiratory tract. Twenty-seven patients (54.0%) of 50 patients positive for MRSA in the respiratory tract yielded MRSA in the feces. Twenty-three patients (85.2%) of the 27 patients positive for MRSA in the fecal flora had received H2-blocker, while 11 patients (47.8%) of the 23 patients negative for MRSA in the fecal flora received H2-blocker; these differences were statistically significantly (p < 0.01). These findings suggest the possible role of feces in hospital infection with MRSA and the necessity for careful administration of H2-blocker to patients positive for MRSA in the respiratory tract.

Aged↗