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Biomedical subjects

Y Yamamura

Publications and source records attributed to Y Yamamura.

At least 37 records · Page 2Linked to original sources
PubMed2001

Lymph node metastasis and preoperative diagnosis of depth of invasion in early gastric cancer.

BACKGROUND: No reports have, to date, focused on the relationship between preoperative determination of the depth of invasion and lymph node metastasis. The present study, under the leadership of the Japanese Gastric Cancer Association, was designed to form a basis for decision making in limited treatment for early gastric cancer (EGC). METHODS: From eight major hospitals in Japan, 2672 gastric cancers whose preoperative depth of invasion was mucosal(M-cancer), and 6209 EGCs, consisting of 3584 mucosal(m-) and 2625 submucosal(sm-) cancers, were collected by questionnaire. All registered patients underwent gastrectomy with D1 or more extensive lymphadenectomy between 1985 and 1998. RESULTS: The accuracy of preoperative diagnosis of depth of invasion of M-cancers was 80.2% (2144/2672). However, of the total of 2432 M-cancers in which no nodal involvement was observed intraoperatively (N0), histological examination of the resected specimens confirmed that lymph node metastasis was absent in 2353 (96.8%). The frequencies of lymph node metastasis in early gastric, m-, and sm-cancers were 8.9%, 2.5%, and 17.6%, respectively. Node involvement was associated with a higher frequency of undifferentiated than differentiated histology, as well as with greater tumor size. The incidences of lymph node metastasis in m-cancers with a diameter of less than 4 cm, and in sm-cancers with a diameter below 1 cm were 1.3% (37/2837) and 4.9% (4/82), respectively. These metastases rarely extended beyond the first tier. CONCLUSION: N0 and M-cancers, m-cancers less than 4 cm in diameter, and sm-cancers no larger than 1 cm in diameter may be appropriate indications for limited surgery.

Chi-Square Distribution↗
PubMed2001

Iron accumulation in the substantia nigra of autosomal recessive juvenile parkinsonism (ARJP).

Autosomal recessive juvenile parkinsonism (ARJP) is a distinct clinical and genetic entity characterized by highly selective neuronal death in the substantia nigra (SN) and locus coeruleus neurons without Lewy body formation. The mechanism of neuronal death of ARJP is still unknown. Our study demonstrated that iron staining was more intense in ARJP than in both controls and sporadic Parkinson's disease (PD), and there were differences in the pattern of distribution of iron staining between ARJP and PD. In addition neurites of SN in ARJP showed intense iron staining. Thus, we postulate that oxidative stress may play an important role in the neurodegeneration that occurs in ARJP.

Journal Article↗
PubMed2001

Enhanced interferon-gamma by CD8+ CD28- lymphocytes from HIV+ patients.

Flow cytometric analysis of T cells from HIV+ and normal individuals activated for 15 hr showed that the percentage of cells producing interferon-gamma (INFgamma) was enhanced approximately threefold (39 compared to 14%) in the HIV+ CD8+ population. Activation modes, other than anti-CD3 with PMA, were ineffective, and in no case did the percentage of HIV+ CD4+ T cells show increased INFgamma production over controls. Enhanced INFgamma production was not induced by either anti-CD3 or PMA alone, or anti-CD3 or ConA with anti-CD28, or enhanced by N-acetylcysteine. In contrast to INFgamma production, the percentage of CD4+ T cells producing interleukin-2 (Il-2) greatly exceeded that of the CD8+ T cells. The results from flow cytometry analyses of HIV+ CD8+ T cells was supported by quantitative analysis of INFgamma mRNA (by PCR) and INFgamma secretion by ELISA. These methods showed a sixfold and three- to fivefold increase, respectively, on a per cell basis. As HIV infection progresses, as shown by loss of CD4+ T cells, the proportion of CD8+ CD28- T cells increases, and it is this T cell subset that is responsible for 80% or more of the enhanced INFgamma production. The enhanced INFgamma in HIV+ patients derives from two factors: the increase in CD8+ CD28- cells to 70% and the percentage producing INFgamma (60%, compared to 21% for CD8+ CD28+ cells). Our findings of a substantial increase in INFgamma production in HIV infection arising from the increased number of CD8+ CD28- T cells are compatible with clinical studies which show elevated INFgamma in HIV+ serum and INFgamma producing CD8+ T cells dominating HIV+ lymph nodes. We also found a significantly decreased proliferative response of the HIV+-derived CD8+ T cell fraction with coactivator anti-CD-28, in contrast to PMA (with anti-CD3), which is probably a reflection of the diminished population of CD8+ CD28+ T cells in HIV+ donors compared to normal donors (30.7 compared to 67.9%).

Adult↗
PubMed2001

The relationship between alphaB-crystallin and neurofibrillary tangles in Alzheimer's disease.

AlphaB-crystallin is known as a small heat shock protein with a cytoprotective function. This study was undertaken to investigate the relationship between alphaB-crystallin and changes seen in Alzheimer's disease. The distribution and immunohistochemical characteristics of alphaB-crystallin positive neurones in the cerebral cortices of 4 patients with Alzheimer's disease were examined. AlphaB-crystallin positive neurones were mainly distributed in the limbic and paralimbic regions, namely parahippocampal gyrus, fusiform gyrus, cingulate cortex, middle and superior frontal gyrus, and insular cortex, which corresponded to commonly affected regions in Alzheimer's disease. Moreover, such neurones were present predominantly in the III or V layer of the cerebral cortex. The number of alphaB-crystallin positive neurones increased in parallel with the neuronal loss. Logistic regression analysis revealed a significant relation between the density of alphaB-crystallin positive neurones and that of extracellular neurofibrillary tangles (NFTs), with a correlation coefficient (r) of 0.57 and P < 0.0001 in 14 regions of the cerebral cortex. In contrast, the relation was not statistically significant between the density of alphaB-crystallin positive neurones and that of classical senile plaques, diffuse plaques or intracellular NFTs. Modified Gallyas-Braak (GB) staining on alphaB-crystallin positive neurone demonstrated several patterns of the structures: faint GB positive structures in the swollen perikaryon with straight neurites, fine granules compressed and contorted into fuzzy bundles, intensely GB positive filamentous structures together with fine granules and very intensely GB positive ring-like NFTs in a swollen perikaryon with curved neurites. In positive neurones, the density of ring-like NFTs correlated with that of atrophic perikaryon, or bent neurites and a decrease in the immunoreactivity of alphaB-crystallin. These data suggest that a close relationship exists between the appearance of alphaB-crystallin in neurones, extracellular NFTs, and neurofibrillary formation in alphaB-crystallin positive neurones in Alzheimer brain.

Aged↗
PubMed2001

[Effect of mouth wash on the removing fluticasone propionate delivered by dry powder inhaler in mouth].

The effect of mouth wash on the removal of drug residues in both mouth and pharynx after the use of fluticasone propionate dry powder inhaler (FP-DPI) was studied. The concentration of FP in mouth wash after sprinkle and inhalation of Flutide 50, 100, 200 Rotadisk was determined by HPLC-UV. The total amount of the removed FP was measured by the sum of the concentration of FP in 5 times of mouth washes. The mouth wash procedures removed totally 79.3 +/- 4.4% (50 micrograms), 68.5 +/- 3.6% (100 micrograms), 69.3 +/- 3.4% (200 micrograms) of sprinkled amount of FP and 29.5 +/- 11.1% (50 micrograms), 35.6 +/- 6.6% (100 micrograms), 31.6 +/- 8.3% (200 micrograms) of inhaled, respectively. It was required for the removal of 90% of the totally recovered FP to do two times of mouth washes in each case. These data suggest that the mouth wash is an effective precaution for candidiasis induced by FP delivered by DPI.

Administration, Inhalation↗
PubMed2001

[Development of an inspection-supporting system using drug images for unit dose packages].

When inspecting unit-dose packaged drugs, there would be some possibility of inspection errors and ultimately dispensing errors due to pharmacist's incorrect memory of drug identification. Therefore, this study was aimed to establish a computer-aided system for inspecting drugs of unit dose packages more accurately and efficiently. First, we analyzed the identifiability of 5846 tablets and capsules using drug codes, in order to define an identification problem for unit dose-packaged drugs. It was shown that as much as 36% of the drugs do not have any codes, 4.0% of the code-marked drugs have identical codes with others, and that 9.7% of the drugs with codes on both sides of the surface share the same code with other drugs. Thus, it was clearly shown that in many cases it is impossible to identify pharmaceuticals exactly using drug codes only. On the other hand, it was indicated that approximately 80% of the drugs which were not identified with drug codes only, could be identified when additional information on drugs' color, size, form, and splitting line was provided. Therefore, in this study, we designed an inspection-supporting system to present promptly all the information necessary for the drug identification by displaying real drug images as linked with prescribing information on the monitor. Retrieval of prescription data from the order entry host was automatically performed by entering patient's ID number or by selecting a patient from the name list of patients at the inspection terminal computer. Moreover, the system was equipped with abilities to automatically check drug interactions and duplicate prescriptions, to provide various information of prescribed drugs and to monitor patients' drug history. We used the developed system and evaluated that it is a useful tool for accurate and efficient inspection of unit dose-packaged drugs. In addition, the quality of drug inspection increased by utilizing system functions such as checking drug interactions and providing drug information.

Clinical Pharmacy Information Systems↗
PubMed2001

Metallothionein expression and tumor growth in the transplantable pregnancy-independent mouse mammary tumor.

In various human tumors, a metal binding protein, metallothionein (MT) is reported to play an important role in carcinogenesis. In the present preliminary study, MT expression and tumor growth were investigated in transplantable pregnancy-independent mammary tumors (TPIMT) derived from pregnancy-independent mammary tumors (PIMT) in GR/A mice, in order to study the possible role of MT in mammary carcinogenesis. TPIMT as well as PIMT showed MT expression in tumor cells in all of the successive transplantations. A negative correlation was observed between MT expression in transplanted tumor tissues and their growth in the hosts (r=-0.53, p<0.05). The present study indicates that MT is a useful marker of tumor progression in TPIMT.

Animals↗
PubMed2001

Reconstructing population history using JC virus: Amerinds, Spanish, and Africans in the ancestry of modern Puerto Ricans.

The roots of the Hispanic populations of the Caribbean Islands and Central and South America go back to three continents of the Old World. In Puerto Rico major genetic contributions have come from (1) Asians in the form of the aboriginal Taino population, an Arawak tribe, present when Columbus arrived on the Island, (2) Europeans, largely Spanish explorers, settlers, government administrators, and soldiers, and (3) Africans who came as part of the slave trade. Since JC virus (JCV) genotypes characteristic of Asia, Europe, and Africa have been identified, and excretion of JCV in urine has been proposed as a marker for human migrations, we sought to characterize the JCV strains present in a Caribbean Hispanic population. We found that the strains of JCV present today in Puerto Rico are those derived from the Old World populations represented there: Types 1B and 4 from Spain, Types 3A, 3B, and 6 from Africa, and Type 2A from Asia. The Type 2A genotype represents the indigenous Taino people. This JCV genotype was represented much more frequently (61%) than would be predicted by the trihybrid model of genetic admixture. This might be attributable to characteristics of JCV Type 2A itself, as well as to the nature of the early relationships between Spanish men and native women. These findings indicate that the JCV strains carried by the Taino Indians can be found in today's Puerto Rican population despite the apparent demise of these people more than two centuries ago. Therefore, molecular characterization of JCV provides a tool to supplement genetic techniques for reconstructing population histories including admixed populations.

Adult↗
PubMed2001

Mycobacterium kansasii arthritis of the foot in a patient with systemic lupus erythematosus.

Mycobacterium kansasii, an atypical Mycobacterium, may cause serious illness in humans. We describe a M. kansasii infection of the foot joint, which was diagnosed in a 46-year-old woman with systemic lupus erythematosus. The diagnosis was based on a positive culture from degenerative tissue and histological diagnosis of a synovium. We reviewed the literature regarding M. kansasii infection of the joint, bone, and periarticular structures focusing on the complication of rheumatic diseases.

Arthritis, Infectious↗
PubMed2001

[Study on the intensity of MMC and UFT in postoperative adjuvant chemotherapy for gastric cancer--study report of JFMTC Study No. 10].

The purpose of this study was to investigate the correlation between efficacy and dose intensity of postoperative adjuvant chemotherapy with MMC and UFT. A total of 1,410 patients from 180 institutions were allocated into a low-dose group and a high-dose group. The patients in the low-dose group received MMC at 8 mg/m2 on the day of surgery and 3 capsules of UFT (300 mg in tegafur) daily for 6 months. The patients in the high-dose group received MMC at 8 mg/m2 on the day of surgery, and in weeks 4, 10, 16, and 22 after surgery and 6 capsules of UFT (600 mg in tegafur) daily for 6 months. The patients in the high-dose group tended to exhibit higher survival rates than those in the low-dose group, although the difference was not significant. For the n(+)ps(-) patients, however, the survival rates were significantly higher in the high-dose group (p = 0.043). The recurrence-free rates showed a similar tendency. The incidence rates of adverse events were significantly higher in the high-dose group than in the low-dose group. Compliance was poorer in the high-dose group. Although the number of adverse events increases, a better prognosis can be expected with a high dose. These results confirmed a dose-dependency in adjuvant chemotherapy with MMC and UFT.

Antibiotics, Antineoplastic↗
PubMed2001

Involvement of CYP2B6 in n-demethylation of ketamine in human liver microsomes.

Ketamine is metabolized by cytochrome P450 (CYP) leading to production of pharmacologically active products and contributing to drug excretion. We identified the CYP enzymes involved in the N-demethylation of ketamine enantiomers using pooled human liver microsomes and microsomes from human B-lymphoblastoid cells that expressed CYP enzymes. The kinetic data in human liver microsomes for the (R)- and (S)-ketamine N-demethylase activities could be analyzed as two-enzyme systems. The K(m) values were 31 and 496 microM for (R)-ketamine, and 24 and 444 microM for (S)-ketamine. Among the 12 cDNA-expressed CYP enzymes examined, CYP2B6, CYP2C9, and CYP3A4 showed high activities for the N-demethylation of both enantiomers at the substrate concentration of 1 mM. CYP2B6 had the lowest K(m) value for the N-demethylation of (R)- and (S)-ketamine (74 and 44 microM, respectively). Also, the intrinsic clearance (CL(int): V(max)/K(m)) of CYP2B6 for the N-demethylation of both enantiomers were 7 to 13 times higher than those of CYP2C9 and CYP3A4. Orphenadrine (CYP2B6 inhibitor, 500 microM) and sulfaphenazole (CYP2C9 inhibitor, 100 microM) inhibited the N-demethylase activities for both enantiomers (5 microM) in human liver microsomes by 60 to 70%, whereas cyclosporin A (CYP3A4 inhibitor, 100 microM) failed to inhibit these activities. In addition, the anti-CYP2B6 antibody inhibited these activities in human liver microsomes by 80%, whereas anti-CYP2C antibody and anti-CYP3A4 antibody failed to inhibit these activities. These results suggest that the high affinity/low capacity enzyme in human liver microsomes is mediated by CYP2B6, and the low affinity/high capacity enzyme is mediated by CYP2C9 and CYP3A4. CYP2B6 mainly mediates the N-demethylation of (R)- and (S)-ketamine in human liver microsomes at therapeutic concentrations (5 microM).

Aryl Hydrocarbon Hydroxylases↗
PubMed2001

[Rapid quantitative detection of free cancer cells in the peritoneal cavity of gastric cancer patients with real-time RT-PCR, and its prognostic significance].

We have established a rapid and quantitative detection method using real-time RT-PCR on the LightCycler instrument. This method can reproducibly quantitate 10-10(5) CEA expressing colon carcinoma cells per 10(7) peripheral blood leukocytes, a sensitivity comparable with conventional RT-PCR with a wide linear measuring range. Analysis of peritoneal washes from 241 gastric cancer patients with this assay revealed relative values of CEA transcripts that correlate well with the depth of tumor invasion. The sensitivity and specificity of real-time RT-PCR with a cut-off value of 0.25 were 88% and 81%, respectively. At this cut-off value, patients in the real-time RT-PCR (+) group were found to suffer from peritoneal metastasis with a high frequency, while peritoneal recurrence was very rare among patients with real-time RT-PCR (-) results. These results indicate a positive correlation between CEA mRNA levels in peritoneal washes and patient prognosis. We conclude that real-time RT-PCR with hybridization probes is a sensitive, quantitative, specific and rapid method to detect free cancer cells in peritoneal washes.

Ascitic Fluid↗
PubMed2001

Polymorphisms of two fucosyltransferase genes (Lewis and Secretor genes) involving type I Lewis antigens are associated with the presence of anti-Helicobacter pylori IgG antibody.

Helicobacter pylori attach to the gastric mucosa with adhesin, which binds to Lewis b (Le(b)) or H type I carbohydrate structures. The Secretor (Se) gene and Lewis (Le) gene are involved in type I Le antigen synthesis. The present study was performed to investigate the possibility that Se and Le gene polymorphisms alter the risk of H. pylori infection. Two hundred thirty-nine participants were genotyped for Se and Le and tested for the presence of anti-H. pylori IgG antibodies. Using the normal gastric mucosa from 60 gastric cancer patients, we assessed immunohistochemically whether type I Le antigen expression depended on the Se and Le genotypes. The H. pylori infection rate was positively associated with the number of Se alleles (se/se group, 45.1%; Se/se group, 64.6%; and Se/Se group, 73.3%) and negatively associated with the number of Le alleles (le/le group, 76.4%; Le/le group, 68.3%; and Le/Le group, 55.6%). When the subjects were classified into three groups [low risk, (se/se, Le/Le) genotype; high risk, (Se/Se, le/le), (Se/Se, Le/le), and (Se/se, le/le) genotypes; moderate risk, other than low- or high-risk group], the odds ratio relative to the low-risk group was 3.30 (95% confidence interval, 1.40-7.78) for the moderate-risk group and 10.33 (95% confidence interval, 3.16-33.8) for the high-risk group. Immunohistochemical analysis supported the finding that Se and Le genotypes affected the expression of H. pylori adhesin ligands. We conclude that Se and Le genotypes affect susceptibility to H. pylori infection.

Adult↗
PubMed2001

[Clinical study on mortality of rheumatoid arthritis compared with malignant rheumatoid arthritis].

OBJECTIVE: To determine how the mortality of patients with rheumatoid arthritis (RA) behave in comparison with that of patients with malignant rheumatoid arthritis (MRA). METHODS: The mortality of RA patients selected at randam identified in 1991-2000 (n = 104) was compared with that of 18 MRA patients. Hazard ratios of death were calculated with a multivariate survival analysis. A clinical study of patients with both RA and MRA was performed in mortality. RESULTS: Excess mortality was seen in MRA patients in Kaplan-Meier survival curves (p = 0.02 by log-rank test). MRA patients were treated more often with cytostatic and immunosuppressive drugs. Infection was the main cause of death in both RA and MRA patients. Vasculitis was not reported as the cause of death in MRA patients. Secondary amyloidosis played an important role in RA death rather than MRA. CONCLUSION: There remained an excess mortality in MRA patients compared with RA, and infection was attributable to the key cause of death in both RA and MRA suggesting therapeutic side effects.

Aged↗
PubMed2001

[A case of cholinergic urticaria with epileptic seizure and abnormalities on electroencephalogram].

We report a 10-year-old boy with cholinergic urticaria associated with epileptic seizure and abnormalities on electroencephalogram. In March 1999, many red wheals developed over the entire body during exercise and at increased body temperature. In April, systemic red wheals developed during exercise. Simultaneously, loss of consciousness was noted for 2 to 3 minutes. After the patient's body was cooled, consciousness improved, and these exanthemas disappeared. In the Department of Dermatology, his illness was diagnosed as cholinergic urticaria. Neurologically, a heat tolerance and mental strain induced cholinergic urticaria, followed by generalized epilepsy(clonic seizure). In addition, electroencephalography revealed high voltage polyspikes and 14 Hz positive spikes. The mechanism involved in cholinergic urticaria associated with epileptic seizure was assumed as follows: sweat-promoting stimuli, such as heat, exercise and tension, stimulate the autonomic center in the diencephalon or brain stem, and excitation in the autonomic center is transmitted to the efferent sympathetic nerve, causing cholinergic urticaria; when the intensity of stimulation is high, the autonomic center exhibits abnormal activities and causes epileptic seizure.

Autonomic Nervous System↗
PubMed2001

HCV genotype analysis in HCV-HIV-co-infected Puerto Ricans who are injecting drug users: undetermined and mixed infections.

Direct percutaneous exposure is the main route of HCV transmission. In Puerto Rico half of people infected with HIV use illicit drugs. The effects of HCV in the course of HIV infection and vice versa have been extensively studied, but remain highly controversial. This may be due to HCV genetic heterogeneity. Therefore, a complex classification into genotypes has emerged that prompted us to determined how this impacts a population of intravenous drug users (IDUs) co-infected with HIV-1. Using Inno-LiPa II technique, we analyzed samples from 171 HCV-HIV-1-co-infected IDUs and 375 from a general HCV population of unknown HIV or source of infection status. Similar HCV genotype distribution was detected in these populations. HCV genotype 1a was the most frequently in IDUs-co-infected with HIV-1, followed by 1b and 3a. Twenty mixed infections and 5 undetermined genotypes were reported. A reduced HCV viral load was observed in HIV-1 positives with wasting syndrome. Individuals with a high HIV-1 viral load presented a low HCV viral load. There were no correlation between HCV genotypes and AIDS-related event. Patients with genotype 1b showed a higher HCV viral load. Males presented higher HCV viral load than females. Females were predominantly affected by genotype 1a, and men by 1a and 1b. Neither the HCV viral load nor the frequency of genotypes were influenced by the antiretroviral modality. The importance of continuous genotype monitoring is stressed.

Adult↗
PubMed2000

Critical role of Smads and AP-1 complex in transforming growth factor-beta -dependent apoptosis.

Transforming growth factor-beta1 (TGF-beta1) induces not only cell growth inhibition but also apoptosis in hepatocytes, myeloid cells, and epithelial cells. Although Smad proteins are identified as key signal transducers in TGF-beta1-dependent growth inhibition, their roles in the induction of apoptosis are unclear. We show here that both Smad proteins and AP-1 complex are involved in TGF-beta1 signaling for apoptosis. Overexpression of a dominant-negative Smad3 mutant or Smad7, both of which impair Smad-mediated signal transduction, inhibits TGF-beta1-dependent apoptosis. Only the JunD. FosB form of the AP-1 complex is markedly activated during TGF-beta1-dependent apoptosis. FosB substantially enhances Smad3. Smad4-dependent transcription, and dominant-negative FosB blocks TGF-beta1-dependent apoptosis but not growth inhibition. Expression of JunD.FosB enhances induction of apoptosis by TGF-beta1. Moreover, JunD.FosB binds to the 12-O-tetradecanoyl-13-acetate-responsive gene promoter element and recruits Smad3.Smad4 to form a multicomponent complex. These results suggest that Smad proteins and AP-1 complex synergize to mediate TGF-beta1-dependent apoptosis.

Animals↗