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Biomedical subjects

Osamu Takahashi

Publications and source records attributed to Osamu Takahashi.

At least 19 recordsLinked to original sources

A retrospective review of 226 hospitalized patients with fever.

OBJECTIVE: To describe characteristics and outcomes for patients hospitalized with fever, not only patients with fever of unknown origin (FUO). METHODS: Medical records were reviewed for 226 consecutive patients hospitalized in a Japanese referral hospital with fever as one of the clinical problems. RESULTS: Although the majority of illnesses involved some sort of infection (54%), noninfectious inflammatory diseases, particularly adult Still's disease (n=6) and primary vasculitis syndromes (n=5) including 3 cases of Behçet's disease, represented the leading cause in patients who met the definition of FUO [16/51(31%)]. Tuberculosis (n=6) and psychological disorders (n=6) were associated with late diagnosis. However, there was only one patient meeting the definition of FUO among those with a psychological disorder. Among the patients with prolonged fever who did not strictly meet the definition of FUO, there was a considerable number of patients with critical illnesses, such as intra-abdominal abscess, polymyalgia rheumatica, sarcoidosis, ulcerative colitis, Castleman's disease, hematological and solid malignancies, and panhypopituitarism. Drug-induced fever, systemic viral infection and unspecified vasculitis were difficult to definitively diagnose, although these pathologies were suspected as causes of fever. Follow-up of patients without definitive diagnosis at discharge confirmed that the fever subsided spontaneously or the cause of fever was properly treated after diagnosis in every patient and that none died of the underlying febrile illness. CONCLUSIONS: The present findings, from all patients displaying fever at hospitalization, are in agreement with findings from prior FUO series. Strict use of the definition of FUO is thus unwarranted when managing patients with prolonged fever.

Adult↗

Intestinal surgery in advanced ovarian cancer.

PURPOSE OF REVIEW: This review examines the current role of intestinal surgery in advanced ovarian cancer. Institutions differ considerably in surgical procedures and therapeutic outcomes for this disease. Moreover, therapeutic outcomes are influenced by the inclusion criteria for surgical procedures and the degree of surgical completion. We discuss the role of intestinal surgery and suggest surgical indications for intestinal surgery in advanced ovarian cancer. RECENT FINDINGS: Prognosis in advanced ovarian cancer is better when there is a smaller postoperative tumor mass. However, it is necessary to investigate the effects of intestinal surgery on residual tumor mass and its prognostic benefits. Here, recent reports were reviewed to ascertain the usefulness and safety of intestinal surgery for advanced ovarian cancer and examine surgical indications and institutional requirements. SUMMARY: By performing aggressive intestinal surgery such as combined bowel resection, optimal cytoreductive surgery can be performed in 70-98% of cases. The morbidity associated with intestinal surgery is acceptably low. Prognostic benefits for intestinal surgery are clear in patients with operable ovarian cancer with no residual disease. Women with suspected ovarian cancer should therefore be referred to centers with experienced tumor surgeons.

Colectomy↗

Inner-shell excitation spectroscopy and fragmentation of small hydrogen-bonded clusters of formic acid after core excitations at the oxygen K edge.

Inner-shell excitation spectra and fragmentation of small clusters of formic acid have been studied in the oxygen K-edge region by time-of-flight fragment mass spectroscopy. In addition to several fragment cations smaller than the parent molecule, we have identified the production of HCOOH.H+ and H3O+ cations characteristic of proton transfer reactions within the clusters. Cluster-specific excitation spectra have been generated by monitoring the partial ion yields of the product cations. Resonance transitions of O1s(C[double bond]O/OH) electrons into pi(CO)* orbital in the preedge region were found to shift in energy upon clusterization. A blueshift of the O1s(C[double bond]O)-->pi(CO)* transition by approximately 0.2 eV and a redshift of the O1s(OH)-->pi(CO)* by approximately 0.6 eV were observed, indicative of strong hydrogen-bond formation within the clusters. The results have been compared with a recent theoretical calculation, which supports the conclusion that the formic-acid clusters consist of the most stable cyclic dimer andor trimer units. Specifically labeled formic acid-d, HCOOD, was also used to examine the core-excited fragmentation mechanisms. These deuterium-labeled experiments showed that HDO+ was formed via site-specific migration of a formyl hydrogen within an individual molecule, and that HD2O+ was produced via the subsequent transfer of a deuterium atom from the hydroxyl group of a nearest-neighbor molecule within a cationic cluster. Deuteron (proton) transfer from the hydroxyl site of a hydrogen-bond partner was also found to take place, producing deuteronated HCOOD.D+ (protonated HCOOH.H+) cations within the clusters.

Journal Article↗

Molecular diversity of alveolates associated with neritic north atlantic radiolarians.

Seven species of polycystine radiolarians and one phaeodarian species were investigated in order to determine the diversity of their associate organisms and their species specificity. Twelve partial 18S ribosomal DNA (rDNA) sequences were obtained showing a high diversity of associates, both within spumellarian and nassellarian radiolarians and among species. Two of the sequences obtained are highly similar to Scrippsiella, a dinoflagellate genus already reported as a symbiont of polycystine radiolarians. Nine of the new 18S rDNA sequences group with various alveolates. Some of these groups include parasites, such as the lethal endoparasite Amoebophrya, while others consist of non-annotated novel organisms found worldwide in various types of marine environments. We also obtained a sequence from a bacillariophytan highly similar to the 18S rDNA of the diatom species Diatoma tenue, which may derive from radiolarian food. Additionally, this is the first study to report on a phaeodarian associate.

Animals↗

Effect of pressure on the vibrational structure of insensitive energetic material 5-nitro-2,4-dihydro-1,2,4-triazole-3-one.

The Raman spectra of alpha form 5-nitro-2,4-dihydro-1,2,4-triazole-3-one (alpha-NTO, space group P) were measured in a high-pressure vessel diamond anvil cell (DAC). The pressure was increased to 27.6 GPa. In general, Raman bands show a blue shift because of the nature of the molecule packing as a high-pressure effect, but some particular bands exhibited a red shift, disappearance, split, or slight shifting in our experiments. Those red-shifting bands concerning hydrogen bonds, i.e., carbonyl and amino groups, are likely to work as a stabilizer against stimuli to the molecule or crystal. This stabilizing nature might characterize the insensitivity of NTO. Molecular dynamic (MD) calculations were performed to reveal the high-pressure effect of the alpha-NTO crystal. The coordinates of individual atoms in the crystal structure were obtained using X-ray diffraction analysis. The pressure dependence of the power spectra of the correlation functions of the C=O bond length in NTO was calculated. A unique high-pressure effect of the alpha-NTO crystal was found on the power spectra. The peak frequency in the power spectrum of the C=O stretching vibration exhibited a red shift with an increase in pressure to 10.0 GPa, while the peak intensity considerably decreased under the same pressure process, because this bond length increased with an increase in pressure to 10.0 GPa. At a pressure of >20.0 GPa, a blue shift appeared. These results of the MD calculations are in good agreement with our experimental data.

Journal Article↗

Why are physicians not persuaded by scientific evidence? A grounded theory interview study.

BACKGROUND: The government-led "evidence-based guidelines for cataract treatment" labelled pirenoxine and glutathione eye drops, which have been regarded as the standard care for cataracts in Japan, as lacking evidence of effectiveness, causing great upset among ophthalmologists and professional ophthalmology societies. This study investigated the reasons why such "scientific evidence of treatment effectiveness" is not easily accepted by physicians, and thus, why they do not change their clinical practices to reflect such evidence. METHODS: We conducted a qualitative study based on grounded theory to explore physicians' awareness of "scientific evidence" and evidence-supported treatment in relation to pirenoxine and glutathione eye drops, and to identify current barriers to the implementation of evidence-based policies in clinical practice. Interviews were conducted with 35 ophthalmologists and 3 general practitioners on their prescribing behaviours, perceptions of eye drop effectiveness, attitudes toward the eye drop guideline recommendations, and their perceptions of "scientific evidence." RESULTS: Although few physicians believed that eye drops are remarkably effective, the majority of participants reported that they prescribed eye drops to patients who asked for them, and that such patients accounted for a considerable proportion of those with cataracts. Physicians seldom attempted to explain to patients the limitations of effectiveness or to encourage them to stop taking the eye drops. Physicians also acknowledged the benefits of prescribing such drugs, which ultimately outweighed any uncertainty of their effectiveness. These benefits included economic incentives and a desire to be appreciated by patients. Changes in clinical practice were considered to bring little benefit to physicians or patients. Government approval, rarity of side effects, and low cost of the drops also encouraged prescription. CONCLUSION: Physicians occasionally provide treatment without expecting remarkable therapeutic effectiveness, as exemplified by the use of eye drops. This finding highlights that scientific evidence alone cannot easily change physicians' clinical practices, unless evidence-based practices are accepted by the general public and supported by health policy.

Aged↗

Can we omit para-aorta lymph node dissection in endometrial cancer?

BACKGROUND: Patients with endometrial cancer can present with various complicating illnesses, including obesity, diabetes mellitus, hypertension and advanced aging. These patients are at high risk of severe post-operative complications. Thus, the question of whether or not to perform systemic pelvic and para-aortic lymphadenectomy remains controversial for all patients. It is reported that external iliac lymph nodes are the most commonly involved lymph nodes in endometrial cancer, and para-aortic lymph node (PAN) metastases spread via a route shared by the common iliac lymph nodes. The aim of this study was to evaluate the potential efficacy of omitting PAN dissection when metastasis of the common iliac and external iliac lymph nodes is negative. METHODS: Between January 1994 and June 2004, a total of 101 patients at Akita University Hospital who had undergone total hysterectomy and bilateral salpingo-oophorectomy, total pelvic lymphadenectomy and para-aortic lymphadenectomy to the level of the renal vein for endometrial cancer were enrolled in this study. RESULTS: Eleven patients in all were found to have metastasis for PANs. Among 13 patients with common and/or external iliac positive lymph nodes, 10 showed PAN metastasis. Of the 88 patients with negative lymph nodes, 87 showed no PAN metastasis. Based on these data, common and/or external iliac lymph nodes had 90.9% sensitivity (10/11) and 96.7% specificity (87/90) for detecting PAN metastasis. CONCLUSION: Para-aortic lymphadenectomy might be avoided by the negativity of such lymph nodes, thereby minimizing post-operative complications.

Adenocarcinoma, Clear Cell↗

Theoretical study of ion desorption from poly-(methyl methacrylate) and poly-(isopropenyl acetate) thin films through core excitation.

Site-specific chemical reactions following core excitation of poly-(methyl methacrylate) (PMMA) and poly-(isopropenyl acetate) (PiPAc) thin films were investigated. New x-ray absorption spectra of PMMA and PiPAc at the C and O K edges and theoretical spectra within the framework of density functional theory using model molecules were reported, and some new peak assignments were proposed for these spectra. Core-hole excited state molecular dynamics simulations were performed to discuss dissociation dynamics for the target systems, and some specific reaction mechanisms were discussed and explained theoretically; for example, the amount of CH3 ion fragments for PMMA was enhanced at the C and O K edges through the existence of the repulsive sigma*(O-CH3) excited state.

Journal Article↗

Auger decay calculations with core-hole excited-state molecular-dynamics simulations of water.

We report a new theoretical procedure for calculating Auger decay transition rates including effects of core-hole excited-state dynamics. Our procedure was applied to the normal and first resonant Auger processes of gas-phase water and compared to high-resolution experiments. In the normal Auger decay, calculated Auger spectra were found to be insensitive to the dynamics, while the repulsive character of the first resonant core-excited state makes the first resonantly excited Auger decay spectra depend strongly on the dynamics. The ultrafast dissociation of water upon O(1s)-->4a(1) excitation was analyzed and found to be very sensitive to initial vibrational distortions in the ground state which furthermore affect the excitation energy. Our calculated spectra reproduce the experimental Auger spectra except for the Franck-Condon vibrational structure which is not included in the procedure. We found that the Auger decay of OH and O fragments contributes to the total intensity, and that the contribution from these fragments increases with increasing excitation energy.

Journal Article↗

What is the origin of the premotor potential recorded from the second lumbrical?

When recording with a palm electrode, a premotor potential (PMP) precedes the compound muscle action potential that is evoked from the second lumbrical muscle following median nerve stimulation. The origin of this PMP has been uncertain. We demonstrate that median sensory nerve action potentials (SNAPs) can be recorded orthodromically with the palm electrode and conclude that the origin of the PMP is a median SNAP arising from antidromically activated digital sensory branches.

Action Potentials↗

Male reproductive toxicity of four bisphenol antioxidants in mice and rats and their estrogenic effect.

Male mice and rats were fed a diet containing four bisphenol antioxidants, 2,2'-methylenebis(4-ethyl-6-tert-butylphenol) (ME), 2,2'-methylenebis(4-methyl -6-tert-butylphenol) (MM), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol) (BM), or 4,4'-thiobis(3-methyl-6-tert-butylphenol) (TM) at levels of 0.06-0.25% for 2 months. BM and TM decreased epididymal, seminal vesicular, prostate and preputial weights, and injured seminiferous tubules in mice in a dose-dependent fashion. BM and TM also reduced sex accessory organ weights and sperm production capacity in rats, but MM and ME were more toxic to rats than BM and TM. ME and MM did not bind ERalpha up to 10(-3) M, while BM and TM competitively bound ERalpha against beta-estradiol (E2). Fifty percent inhibitory concentrations (IC50 s) of BM, TM, and bisphenol A (positive control) against E2-binding were 7.3 x 10(-6) M, 1.8 x 10(-5) M, and 1.4 x 10(-5) M, respectively. When ovariectomized (OVX) mice were sc administered TM at doses of 60 and 300 mg/kg/day for 4 days, or when OVX mice were fed BM in the diet at a level of 0.25% for 2 months, uterine weight was significantly increased. These results suggest that BM and TM are weakly toxic, possibly through an estrogenic mechanism to male reproductive organs in mice as well as rats, while MM and ME may be the direct testicular toxins in rats but not mice.

Animals↗

Evaluation of cuff-wrapping methods for the determination of ankle blood pressure.

OBJECTIVE: The ankle-brachial index, which is calculated by dividing ankle systolic blood pressure by brachial systolic blood pressure, is useful in diagnosing peripheral arterial disease. Consensus has not been reached, however, on a standard method for measuring ankle systolic blood pressure. This study evaluated two cuff-wrapping methods for measuring ankle systolic blood pressure, compared with intra-arterial pressure as a gold standard. METHODS: Study participants were 24 consecutive adult patients who underwent surgery under general anesthesia at Kyoto Prefectural University Hospital in Japan between January and March 2002. Indirect ankle systolic blood pressure was measured in the posterior tibial artery using a Doppler device and two cuff-wrapping methods: spiral, and straight. Direct ankle systolic blood pressure was measured in the dorsalis pedis artery. RESULTS: Mean difference in ankle systolic blood pressure between indirect and direct measurements (indirect minus direct) was 1.4 mmHg [standard deviation of the difference (SDd), 17.6 mmHg] with the straight method and -1.4 mmHg (SDd, 22.2 mmHg) with the spiral method. The limit of agreements (mean difference +/-2 SDd) and intraclass correlation coefficient between two observers were -17.6 to 20.1 mmHg and 0.94, respectively, for the straight method and -39.4 to 40.0 mmHg and 0.78, respectively, for the spiral method. CONCLUSIONS: The straight method, the same cuff-wrapping method used for measuring brachial blood pressure, appears to represent a more suitable wrapping method because of better interobserver reproducibility. Accuracy and reproducibility of indirect ankle systolic blood pressure measurement, however, were not adequately improved by either of the wrapping methods.

Adult↗

Clinical prediction rules for bacteremia and in-hospital death based on clinical data at the time of blood withdrawal for culture: An evaluation of their development and use.

RATIONALE, AIMS AND OBJECTIVES: To develop clinical prediction rules for true bacteremia, blood culture positive for gram-negative rods, and in-hospital death using the data at the time of blood withdrawal for culture. METHODS: Data on all hospitalized adults who underwent blood cultures at a tertiary care hospital in Japan were collected from an integrated medical computing system. Logistic regression was used for developing prediction rules followed by the jackknife cross validation. RESULTS: Among 739 patients, 144 (19.5%) developed true bacteremia, 66 (8.9) were positive for gram-negative rods, and 203 (27.5%) died during hospitalization. Prediction rule based on the data at the time of blood withdrawal for culture stratified them into five groups with probabilities of true bacteremia 6.5, 9.6, 21.9, 30.1, and 59.6%. For blood culture positive for gram-negative rods, the probabilities were 0.6, 4.7, 8.6, and 31.7%, and for in-hospital death, those were 6.7, 15.5, 26.0, 35.5, and 56.1%. The area of receiver operating characteristic for true bacteremia, blood culture positive for gram-negative rods, and in-hospital death were 0.73, 0.64, and 0.64, respectively, in original cohort and 0.72, 0.64, and 0.64 in validation respectively. CONCLUSIONS: The clinical prediction rules are helpful for improved clinical decision making for bacteremia patients.

Aged↗

Adenofibroma of the endometrium protruding into the vaginal cavity: findings on transvaginal ultrasonography, MRI and CT.

Adenofibroma is a rare benign biphasic neoplasm that is classified into the mixed epithelial and mesenchymal tumor group. We report the case of a 42-year-old woman with adenofibroma of the endometrium protruding into the vagina. Transvaginal ultrasonography revealed the tumor as an intravaginal mass containing multiple cystic components. Magnetic resonance imaging (MRI) showed a heterogeneous high-intensity mass filling the vaginal cavity on T2-weighted imaging, with a low-contrast enhanced septum identified within the mass on gadolinium-enhanced, T1-weighted imaging. Contrast-enhanced computed tomography (CT) showed a heterogeneous low-attenuating multicystic mass filling the vaginal cavity. Although preoperative diagnosis of this rare tumor is very difficult, the combination of MRI, CT, and ultrasonography offers a useful diagnostic tool.

Adenofibroma↗

[Study of the echocardiographic diagnosis of acute pulmonary thromboembolism and risk factors for venous thromboembolism].

OBJECTIVES: To identify the relationship of risk factors for atherosclerosis with venous thromboembolism (VTE) and the utility of transthoracic echocardiography in acute pulmonary thromboembolism (APTE). METHODS: In 75 patients with VTE (VTE group), 101 patients with suspected VTE (N group), and 50 control subjects (control group), the frequency of atherosclerosis risk factors such as hyperlipidemia, obesity, hypertension, smoking, and diabetes mellitus and the number of risk factors were evaluated. Transthoracic echocardiographic findings such as tricuspid regurgitation, right ventricular dilation, pulmonary hypertension, and right ventricular dysfunction were evaluated in 15 patients with APTE (APTE group) and 38 patients in the N group (NC group). RESULTS: The incidence of hyperlipidemia in the VTE group was statistically higher than that in the control group (odds ratio 2.16, 95% confidence interval 1.43-3.08). Additionally, the incidence of obesity was higher in the VTE and N groups than in the control group (odds ratio was 2.76, 95% confidence interval 1.67-4.37). Risk factors other than obesity and hyperlipidemia and the number of risk factors were not significant. The incidence of tricuspid regurgitation, right ventricular dilation, and pulmonary hypertension in APTE was statistically greater than that in NC group. Right ventricular dilation and right ventricular dilation + tricuspid regurgitation are reliable findings in echocardiography. However, even combining with tricuspid regurgitation, right ventricular dilation is insufficient to identify or screen patients with APTE. CONCLUSIONS: Hyperlipidemia and obesity may be risk factors for VTE. However, obese patients can manifest similar findings to VTE. Although transthoracic echocardiograpghy is not recommended as a diagnostic or screening test in APTE, it should be used as an ancillary test.

Acute Disease↗

Disordered expression of HOX genes in human non-small cell lung cancer.

We hypothesized that the disordered tissue architecture in cancer results from the cells executing the program designed during ontogeny in a spatio-temporally inappropriate manner. HOX genes are known as master regulators of embryonic morphogenesis, and encode transcription factors which regulate the transcription of the downstream genes to realize the program of body plan. In this study, we quantified the expression levels of 39 HOX genes in 41 human non-small cell lung cancer (non-SCLC) and non-cancerous lung tissues by a comprehensive analysis system based on the real-time RT-PCR method. We found that the expression levels of HOXA1, A5, A10 and C6 in squamous cell carcinoma tissues (and HOXA5 and A10 in adenocarcinoma tissues) were significantly higher than those in the non-cancerous tissues. Comparison of HOX gene expressions between adenocarcinoma and squamous cell carcinoma tissues showed higher expressions of HOXA1, D9, D10 and D11 in squamous cell carcinoma tissues than in adenocarcinoma tissues. Immunohistochemical analysis revealed that HOXA5 and A10 proteins were localized in the cytoplasm of tumor cells in both adenocarcinoma and squamous cell carcinoma tissues. These results suggest that the disordered patterns of HOX gene expressions were involved not only in the development of non-SCLC but also in the histologically aberrant diversity such as adenocarcinoma and squamous cell carcinoma.

Adult↗

Prehospital management of sarin nerve gas terrorism in urban settings: 10 years of progress after the Tokyo subway sarin attack.

Chemical agents have been used previously in wartime on numerous occasions, from World War I to the Gulf War. In 1994 and 1995, sarin nerve gas was used first in peacetime as a weapon of terrorism in Japan. The Tokyo subway sarin attack was the first large-scale disaster caused by nerve gas. A religious cult released sarin gas into subway commuter trains during morning rush hour. Twelve passengers died and about 5500 people were harmed. Sarin is a highly toxic nerve agent that can be fatal within minutes to hours. It causes the clinical syndrome of cholinergic hyperstimulation by inhibition of the crucial enzyme acetylcholinesterase. Therapy of nerve agent toxicity is divided into three categories, decontamination, respiratory support, and antidotes. All of these therapies may be given simultaneously. This article reviews toxicology and management of this acute chemical emergency. To help minimize the possible catastrophic impact on the public, we make several recommendations based on analysis of the Tokyo subway sarin attack and systematically review the current scientific literature.

Antidotes↗

Validation of the auscultatory method for diagnosing peripheral arterial disease.

BACKGROUND: The Ankle brachial index (ABI) has been shown to be useful in diagnosing peripheral arterial disease (PAD). Ankle systolic blood pressures are measured by a Doppler device; however, general physicians cannot always use it in daily practice. The ausculutatory method (AUS) is an alternative method and quite easy to perform, but has not yet been validated in diagnosing PAD. OBJECTIVE: To validate AUS for diagnosing PAD based on ABI, compared with Doppler method as gold standard. METHODS: Cross-sectional study. Study subjects were 119 patients aged 50 years and older, who were consecutively admitted to the division of general internal medicine in two community hospitals in Japan. We measured the systolic blood pressures of the brachial and the posterior tibial arteries by two methods. We calculated the ABI from the systolic blood pressure obtained by these two methods. PAD was considered to be present when ABI </=0.90 by the Doppler method. RESULTS: PAD was diagnosed in 22 (18.5%) of 119 patients. Korotkoff sounds of legs were inaudible by AUS in 47 (39.5%) patients. The likelihood ratios for diagnosing PAD patients by AUS were 2.7 (95% CI 1.9 to 3.9) in cases with inaudible Korotkoff sounds, 0.7 (95% CI 0.2 to 1.9) when ABI </=0.9 and 0.09 (95% CI 0.02 to 0.4) when ABI >0.9. CONCLUSIONS: While AUS is not efficient enough to confirm the presence of PAD based on ABI, it could be clinically useful in excluding PAD when ABI >0.90. When measuring ankle blood pressure by AUS in the daily practice, it is important to realise its strengths and weaknesses.

Aged↗