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Biomedical subjects

K Aoki

Publications and source records attributed to K Aoki.

At least 379 records · Page 21Linked to original sources
PubMed1996

Genome analysis of adenovirus type 3 isolated in Japan.

Adenovirus type 3 (Ad3) isolates, isolated from 45 patients with acute conjunctivitis during the year 1990 in Japan, were studied by DNA restriction enzyme analysis with restriction endonucleases recognizing 6-bp sequences (BamHI, SmaI, HindIII, BglII) and endonucleases recognizing 5- or 4-bp sequences (HinfI and TaqI). All 45 isolates of Ad3 were identified as the genome type Ad3f by six endonucleases. They were further classified into three varieties by HinfI, varieties H1 (87.5%), H2 (8.9%), and H3 (2.2%), and into five varieties by TaqI, varieties T1 (75.6%), T2 (13.3%), T3 (2.2%), T4 (4.5%), and T5 (8.9%). The use of HinfI and TaqI was sufficient to distinguish six subgenome types: types Ad3fH1T1, Ad3fH1T2, Ad3fH1T4, Ad3fH1T5, Ad3fH2T1, and Ad3fH3T3. Among them, Ad3fH1T1 was predominant in areas where the virus is epidemic. The study showed that the same Ad3 genome type, genome type Ad3f, caused acute viral conjunctivitis even in different areas in Japan. The source and the route of infection were suggested to be common in areas where the virus is epidemic.

Adenovirus Infections, Human↗
PubMed1996

Rapid diagnosis of adenoviral conjunctivitis by PCR and restriction fragment length polymorphism analysis.

To detect and identify adenovirus (Ad), we used a combination of PCR and restriction fragment length polymorphism (RFLP) analysis. Nested PCR with two primer sets that hybridize to the conserved region for hexon proteins of 14 prototypes of Ad, Ad serotype 1 (Ad1) to Ad8, -11, -14, -19, -37, -40, and -41, amplified a 956-bp DNA fragment. The amplified fragments from the 14 prototypes were completely differentiated with a combination of three restriction endonucleases, EcoT14I, HaeIII, and HintI. We applied this new method for 127 samples of conjunctival scrapings from patients with conjunctivitis and compared the results with those obtained with the combination of culture isolation and a neutralization test (NT). PCR gave a positive result in 69 of 127 cases (54.3%), while only 61 of the 127 samples (48.0%) tested positive by culture isolation. Compared with isolation, the PCR method had a sensitivity of 100% (61 of 61). Positive PCR samples were further classified as Ad37 (59.5%), -3(31.9%), -11 (4.3%), -8 (2.9%), and -4 (1.4%) by PCR-RFLP analysis. Of eight samples that were PCR positive and culture isolation negative, six were Ad37 and two were Ad8 by PCR-RFLP analysis. These differentiations of isolation-positive samples were identical to the results obtained by the NT. It took only 3 days to detect and identify Ad by PCR-RFLP analysis, whereas it took at least 3 weeks by culture isolation and NT. Our newly developed method of detecting and typing human Ad by PCR-RFLP analysis is more sensitive, accurate, and rapid than the conventional method of culture isolation and an NT.

Adenoviruses, Human↗
PubMed1996

Anti beta 2glycoprotein I antibodies and lupus anticoagulant in patients with recurrent pregnancy loss: prevalence and clinical significance.

Anticardiolipin antibodies (aCL) were found to recognize beta 2glycoprotein I (beta 2GPI) structure altered by its interaction with an oxygen modified solid phase surface by gamma-ray radiation. Lupus anticoagulant (LA) has been reported to comprise anti prothrombin antibodies, anti factor X antibodies and anti beta 2GPI antibodies. The present study focuses on the possible association between antibodies against the altered beta 2GPI structure (anti beta 2GPI antibodies) and LA in patients with recurrent pregnancy loss. Moreover, the clinical significance of both subgroups of so-called antiphospholipid antibodies were investigated to cast light on the controversy of whether aCL and LA are risk factors for pregnancy losses. One hundred and ninety five women with a history of two or more unexplained consecutive miscarriages and 100 control pregnant women were tested. Lupus anticoagulant was detected by the dilute phospholipid activated partial thromboplastin time. Anti beta 2GPI antibodies were measured by the ELISA method using commercially oxygenated microtiter plates. Twenty two (11.3%) and 19 (9.7%) of the 195 recurrent aborters were, respectively, positive for LA and anti beta 2GPI antibodies. Seven (3.6%) of the aborters had both of them. None of the control pregnant women had LA. Three of the control pregnant women had anti beta 2GPI antibodies. Nine (40.9%) of 22 aborters with positive-LA had a history of miscarriages in the second trimester as compared to 8 (4.6%) of 173 aborters with negative-LA. (P = 0.000007, Odds ratio = 14.3). None of the 12 aborters with anti beta 2GPI antibodies but no LA had a history of second trimester-fetal loss. These results support the hypothesis that aCL and LA define two distinct but partly related populations and that aCL include two subtypes of antibodies, with and without LA activity. LA and anti beta 2GPI antibodies appear to be associated with pregnancy loss, with LA being linked not only to abortions in the first trimester but also to miscarriages in the second trimester.

Abortion, Habitual↗
PubMed1996

Ganglioneuroma: computed tomography and magnetic resonance features.

12 patients who had histological proven ganglioneuromas were investigated by computed tomography (CT) and magnetic resonance (MR) imaging. CT scans (n = 11), conventional spin-echo MR images (n = 10) and dynamic MR images (n = 5) were acquired. All lesions showed a well defined, oval shape. Five lesions (42%) showed calcification which was punctate in four and coarse in one on CT. CT attenuation was predominantly low in three of 10 (30%) and intermediate in the remaining seven (70%). In all lesions MR signals were mainly of low intensity on T1 weighted images (T1WI) and of high intensity on T2 weighted images (T2WI). Dynamic MR studies in five cases showed a lack of early enhancement but gradual increasing enhancement. One case had a ganglioneuroblastoma component which showed soft-tissue density and coarse calcifications on CT scans, MR images with intermediate intensity on T1WI and T2WI and early enhancement and little washout on dynamic MR images. In conclusion, ganglioneuroma typically shows punctate calcification and low attenuation on CT and marked hyperintensity on T2WI with gradual increasing enhancement on dynamic MR images. If a ganglioneuroma has atypical CT and MR features, coexistence of a malignant component should be considered.

Adolescent↗
PubMed1996

The influence of work loads on regional differences in sweating rates.

The influence of work loads (20, 40 and 60% VO2max) on regional differences in sweating rates was investigated in six healthy male students. The ratios of local sweating rate (msw) on the chest and back to estimated total sweating rate (mean msw of four sites examined x body surface area) at 20% work load were significantly greater than those on the forearm and forehead, whereas the ratio on the forehead at 60% work load was greater than at the other sites. The ratios on the forearm at 40 and 60% work loads were significantly greater than at 20% work load. The regional differences in sweating rates change with the increase in work load as seen by the greater variation in the ratios of msw on each site at 20% work load compared with 40 and 60% work loads. The results indicate that redistribution of this sweat activity to whole body or head with the rise in work load induces favorable conditions for evaporation and controlling brain temperature.

Adult↗
PubMed1996

Report by the Research Committee of the Ministry of Education, Science, Sports and Culture on evaluation of risk factors for cancer.

Lifestyle habits and other living conditions in Japanese have progressively been changing after the World War II, and the changing trend has been accelerated since 1970. The frequency and distribution of cancer by site in Japan showed marked secular changes during the past decades, just as reflecting the above changes in environmental factors. A large scaled cohort study on cancer at moment was strongly anticipated in Japan, after the cohort study by Dr. Hirayama et al. had ended around 1980 with unexpectedly fruitful results. However, financial problems and other conditions hindered to start such cohort studies. A multicentered collaborative cohort study had planned among the epidemiologists and epidemiology oriented clinicians who have been working on cancer in the communities, resolving problems on cost and others for long term epidemiological issues. A new cohort with a total of 125 thousands of healthy inhabitants living in the areas scattered throughout country was established in 1988-1990, although they were not randomly distributed in area. Some 30 thousands industrial worker cohort has joined in this study, which will be separately analysed. The study was partly granted by the Ministry of Education, Science, Sports and Culture and largely supported by local government and volunteers in each area for ten years. A research committee on this study was organized and are following up all subjects participated for more than ten years, mainly pursuing mortality status, and incidence of cancer for about half population of the cohort is also under study. About 1,000 deaths per year were observed in the first four years and more than 30% were due to cancer. The proportion of moved out of town was small being about 1% per year. The distribution of cancer deaths by site for the first four years was similar to those of general population. This report summarized the study plan and the epidemiological characteristics of the cohort at entry of the study. It also gives a brief account of activities until 1994.

Adult↗
PubMed1996

[The estrogen-induced changes of estrogen receptor in seminal vesicle of immature castrated rat].

We have already reported that estrogen treatment given to immature castrated rats caused proliferative changes in both collagen and smooth muscle in the seminal vesicles of immature rats detected by light microscopy. Herein, we studied the estrogen-induced changes in estrogen receptor (ER) in the seminal vesicles of immature castrated rats by means of enzyme immunoassay, an immunohistochemical method and RT-PCR, to clarify the mechanism of estrogen induced proliferation of collagen and smooth muscle. Immature rats (3 weeks old) were castrated and left untreated for 3 weeks and then injected subcutaneously with estradiol-17 beta (E2-17 beta, 5 micrograms/day) for 7 days before they were killed. The nuclear ER content per gland, mg tissue and mg protein in the seminal vesicles of castrated rats increased markedly compared with those of non-treated rats. Castration also enhanced ERmRNA expression. The immunohistochemical analysis demonstrated the obvious tissue distribution by which the nuclear ER positive cells were densely distributed in the periglandular stroma. The nuclear ER contents per gland, mg tissue and mg protein in the seminal vesicles of estrogen-treated castrated rats were greater than those in castrated rats. Estrogen treatment further enhanced ERmRNA expression in the castrated rats. The immunohistochemical studies demonstrated that the nuclear ER positive cells appeared among the glandular epithelial cells, basal cells and the peripheral stromal cells, in addition to the periglandular stromal cells. These findings suggest that ER is related to the estrogen induced proliferation of collagen and smooth muscle in the seminal vesicles of immature castrated rats.

Animals↗
PubMed1996

[Transesophageal echocardiography as a early postoperative monitoring patients after cardiovascular surgery: analysis of 500 consecutive studies].

In cardiac surgery significant residual lesions increase postoperative morbidity and mortality. To evaluate the usefulness of transesophageal echocardiography (TEE) as a early postoperative monitor in patients immediately after cardiovascular surgery, 500 consecutive patients were studied from April 1990 to December 1994. TEE was performed at the bedside in the intensive-care unit in all of these patients. TEE detected findings unsuspected by other perioperative tests or clinical examination in 103 (20.6%) of 500 patients. Imaging revealed unsatisfactory operative results that necessitated further surgery in 18 (3.6%) of the 500 patients. These data indicate that early postoperative TEE is useful in assessing immediate operative results and identifying patients with unsatisfactory results who are at increased risk for postoperative complications.

Cardiac Surgical Procedures↗
PubMed1996

[A case report of active aortic prosthetic valve endocarditis due to methicillin-resistant Staphylococcus epidermidis].

A 71-year-old woman with active aortic prosthetic endocarditis due to Methicillin-resistant Staphylococcus epidermidis (MRSE) and subannular mycotic aneurysm and paravalvular leakage and acute mitral regurgitation underwent emergent surgical treatment. The mycotic aneurysm was closed using a prosthetic patch after surgical debridement. Re-aortic valve replacement with a 21-mm Hancock II prosthesis was performed at the paraannular position by utilizing the patch. Mitral valve was also replaced with a 27-mm Hancock II prosthesis. Antibiotic therapy was provided by vancomycin combined with rifampicin and gentamicin. The following regimen was given, vancomycin 1 g i.v. q12h for 6 weeks plus gentamicin 80 mg/day i.v. for 4 weeks plus rifampicin 450 mg/day orally for 6 weeks. Vancomycin and gentamicin doses were modified appropriately according to the monitored serum levels in the patient with renal failure. Postoperative course was uneventful. The patient is doing well 11 months after surgery and no recurrence of infection has been seen. We conclude that prompt surgical removal of the infected sources and appropriate antibiotic therapy based on the bacteriology may be the only curative treatment for uncontrolled infection at the active phase of MRSE prosthetic endocarditis.

Aged↗
PubMed1996

[Rapid detection and identification of human adenovirus directly from conjunctival scrapings by polymerase chain reaction and restriction fragment length polymorphism analysis].

Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis were combined for detection and identification of adenovirus (Ad), a common agent of conjunctivitis in Japan. Nested-PCR with two primer sets that hybridize to the conserved region for hexon protein of 14 prototypes of Ad serotype 1 to 8, 11, 14, 19, 37, 40, and 41, amplified 956 bps DNA fragment. The amplified fragments from 14 prototypes were completely differentiated with the combination of three restriction endonucleases, Eco T14I, Hae III, and Hin fI. We applied this new method to 70 conjunctival scrapings from patients with conjunctivitis, and compared the results with those of the combination of culture isolation and neutralization test. PCR was positive in 38 out of 70 samples (54.3%), whereas 33 of 70 samples (47.1%) were positive by cell culture. Compared with cell culture isolation, the PCR method had a sensitivity of 100% (33 of 33). Positive PCR samples were further classified into Ad 37 (44.7%), 3 (39.5%), 11 (7.9%), 8 (5.3%), and 4 (2.6%) by PCR-RFLP analysis. Of five samples that were PCR positive and cell culture negative, three samples were Ad 37 and two were Ad 8 by PCR-RFLP analysis. These differentiations of cell culture positive samples were identical to the results of the neutralization test. It took only about three days to detect and identify Ad by PCR-RFLP analysis, whereas it took at least two weeks by culture isolation and neutralization test. Our newly developed method of detecting and typing human Ad by PCR-RFLP analysis is more sensitive, accurate, and prompt than the conventional cell culture isolation and neutralization test.

Adenovirus Infections, Human↗
PubMed1996

Serotyping of Chlamydia trachomatis from inclusion conjunctivitis by polymerase chain reaction and restriction fragment length polymorphism analysis.

A molecular biological method of detecting and serotyping Chlamydia trachomatis (C. trachomatis) directly from conjunctival specimens by polymerase chain reaction (PCR) was developed and applied to the diagnosis of inclusion conjunctivitis. We amplified 1.2 kbp DNA fragments of ompA gene from 15 reference strains of C. trachomatis by two-step PCR using two pairs of primers. Restriction fragment length polymorphism analysis using a combination of three endonucleases (HinfI, HindIII and HhaI) completely differentiated 13 of the 15 serovars; the exceptions were B and Ba. We then used this method for 18 strains of C. trachomatis isolated from Japanese patients with inclusion conjunctivitis, serotyping them into six groups: D (5/18), G (5/18), E (3/18), H (2/18), F (1/18), and K (1/18). In our comparison of cell culture isolation with PCR analysis of 38 conjunctival swabs from 35 patients in Sapporo with follicular conjunctivitis, 8 were positive in culture isolation and were also positive in two-step PCR. Twenty-five of 26 strains (the 18 isolated strains and 8 strains amplified by two-step PCR) were genotyped to D, G, H, E, F, and K. One isolated strain could not be identified. The C. trachomatis which causes inclusion conjunctivitis in Japan appears to have a distribution of serovars similar to that of the sexually transmitted diseases.

Adolescent↗
PubMed1996

[Nonrheumatic calcification of the mitral valve in patients with stenotic calcified bicuspid aortic valve].

The pathogenesis of nonrheumatic calcification of the mitral valve was investigated by analyzing the clinical and echocardiographic characteristics of patients with mitral valvular calcification without any findings suggestive of rheumatic heart disease or infective endocarditis. Calcification of the mitral valve was observed in nine patients, who all had calcified stenotic (aortic valve area < 1 cm2) bicuspid aortic valve. Calcification of the mitral valve was localized to the basal portion of ventricular aspect of the anterior mitral leaflet and contiguous to that of the aortic valve. Mobility and thickness of the mitral leaflet was normal except for the calcified portion. Calcification of the mitral valve was not contiguous to posterior mitral annular calcification nor was related to direction of aortic regurgitant flow. In patients with calcified stenotic bicuspid aortic valve, calcification of the mitral valve was not associated with location of the two aortic cusps, aortic valve area, aortic valvular peak pressure gradient, direction of the left ventricular outflow, end-diastolic left ventricular outflow tract dimension, end-diastolic dimension of the aortic annulus, incidence of aortic regurgitation, calcification of the aortic arch, or risk factors of atherosclerosis. Six patients with mitral valvular calcification had aortic valve replacement. Preoperative coronary angiogram of these patients was normal. Calcification of the aortic valve was on the ventricular and aortic aspects. The calcification of the aortic valve, anterior mitral ring, or anterior mitral leaflet was not rheumatic in these six patients. Rheumatic disease, risk factors of atherosclerosis, mechanical stress by left ventricular outflow or aortic regurgitant flow, or mitral annular calcification did not appear to be related to mitral valvular calcification. The distribution of aortic and mitral valvular calcification suggested that the calcification of the mitral valve was due to progression of calcification of the bicuspid aortic valve.

Aged↗
PubMed1996

Cytokine production in children outgrowing hen egg allergy.

BACKGROUND: Approximately 40 to 80% of egg-allergic children outgrow egg allergy after 2 to 5 years. OBJECTIVE AND METHODS: To detail the immunologic mechanisms involved in the development of tolerance to egg proteins, the balance between interleukin 4 (IL4) and interferon-gamma (IFN-gamma) synthesis in patients with active atopic dermatitis allergic to hen egg and in those outgrowing hen egg allergy was evaluated. RESULTS: A marked increase in IL4 and a decrease in IFN-gamma synthesis by peripheral blood lymphocytes following ovalbumin (OVA) specific in vitro stimulation was observed in active atopic dermatitis. In contrast, OVA-induced IL4 synthesis in patients in remission was comparable to that in normal individuals. An intriguing finding was higher production of IFN-gamma by lymphocytes from ovalbumin-insensitive patients in remission as compared to normal individuals following antigen stimulation, although cell proliferation in OVA-stimulated lymphocytes was reduced in patients during remission. CONCLUSION: OVA antigen may be capable of inducing a population of Th1-type cells to produce cytokines such as IFN-gamma, resulting in suppression of Th2-type responses, i.e. IL4 secretion. We speculate that the changes in the balance of relevant antigen-induced cytokine synthesis seen in such patients may be causally associated with the improvement in their clinical status.

Antigens↗
PubMed1996

[Third mitral valve replacement--review of clinical aspects and surgical management in 10 cases].

Third mitral valve replacement (3rd MVR) have become more frequent as use of replacement procedures has become more widespread. However, little information exists to clearly document the determinants of 3rd MVR. To evaluate backgrounds and risks and complications of 3rd MVR, we reviewed data on 10 patients (6 male and 4 female, age averaged 58 +/- 8 years) who underwent 3rd MVR because of prosthetic valve malfunction during December 1986-May 1995. This represented 7.1% of total number of reoperations for valve surgery (10/140) during that period. The incremental effect of the 3rd MVR on hospital mortality and mobidity was studied by comparing first mitral valve replacement (1st MVR) and second mitral valve replacement (2nd MVR) and 3rd MVR. After an interval of 134 +/- 23 months, 3rd MVR was undertaken for congestive heart failure due to primary tissue failure in 65%, paravalvular leakage in 20%, prosthetic valve endocarditis in 15%. One patient died at 11 days postoperatively, for a mortality rate of 10%. Cause of death was related to multiple organ failure due to low cardiac output syndrome. The surgical risk of 2nd MVR and 3rd MVR is higher than that of 1st MVR, but there is no conclusive evidence that the difference between 2nd MVR and 3rd MVR is statistically significant. With improvement intraoperative strategies, the operative risk in patients undergoing 3rd MVR has been markedly reduced.

Bioprosthesis↗
PubMed1996

[Surgical pathology of infective endocarditis].

Underlying pathologic disorders of infected valves were analyzed in 36 consecutive patients with infective endocarditis (from April 1987 to May 1995) of 18 aortic, 11 mitral and 8 prosthetic valves. Among 29 cases of native valve endocarditis, 27 had known organic changes [aortic valve prolapse 8, bicuspid aortic valve 4, annuloaortic ectasia 1, mitral valve prolapse 9 (including 2 cases associated with hypertrophic cardiomyopathy), looping chordae 1, rheumatic heart disease 4]. However, the remaining two cases had unknown etiology. Histological examination of these two aortic valves revealed proliferation of small vessels and remnants of vascular smooth muscle cells, suggesting postinflammatory valve prolapse. Five cases with definite pathology had no clinical signs of infection. The preponderance of surgically resected valves with infective endocarditis in Japan is non-rheumatic in origin.

Adult↗
PubMed1995

Overexpression of the PRAD1 oncogene in a patient with prolymphocytic leukemia with t(11;14)(q13;q32).

Prolymphocytic leukemia (PLL) was diagnosed by morphologic and immunophenotypical studies in a 72-year-old Japanese man. Massive splenomegaly was present but lymphadenopathy was minimal in this case. Chromosomal analysis of peripheral mononuclear cells showed t(11;14)(q13;q32) in all metaphases examined, except for one normal karyotype. Northern blot analysis of RNA prepared from leukemic cells obtained from the patient revealed overexpression of the PRAD1/cyclin D1 proto-oncogene, which has not been described previously in patients with PLL.

Aged↗
PubMed1995

Liposome-mediated in vivo gene transfer of antisense K-ras construct inhibits pancreatic tumor dissemination in the murine peritoneal cavity.

K-ras point mutation occurs at a characteristically high incidence in human pancreatic cancer. Plasmids expressing antisense (AS), AS-K-ras-LNSX or sense K-ras gene fragment, were first transduced into three human pancreatic cancer cell lines (AsPC-1, MIAPaCa-2, and BxPC-3) by liposome-mediated transfection. A stable expression of antisense or sense K-ras RNA was detected by Northern blot analysis, and Western blot analysis confirmed a reduction of up to 20% of K-ras-specific p21 protein in AsPC-1 cells transduced with AS-K-ras-LNSX. The growth of pancreatic cancer cells with K-ras point mutations (AsPC-1 and MIAPaCa-2) was significantly suppressed after transduction of AS-K-ras-LNSX, although the effect of antisense construct was not found in cells with a wild-type K-ras gene (BxPC-3). Next, to test the efficacy in vivo, AsPC-1 cells were inoculated into the intraperitoneal cavity of nude mice, and 3 days later, the AS-K-ras-LNSX:liposome complex was injected i.p. 3 times. Twenty-eight days after tumor cell inoculation, 9 of 10 control mice developed peritoneal dissemination and/or solid tumors on the pancreas, whereas only 2 of 12 mice treated with AS-K-ras-LNSX showed any evidence of tumors. Although PCR analysis indicated that the injected DNA was delivered to various organs except for the brain, treatment-related toxicity was not observed. This study shows that the liposome-mediated in vivo gene transfer of antisense K-ras construct may be a useful therapeutic strategy for pancreatic cancer.

Animals↗