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Biomedical subjects

T Tamura

Publications and source records attributed to T Tamura.

At least 631 records · Page 35Linked to original sources

A randomized prospective study of imipenem-cilastatin with or without amikacin as an empirical antibiotic treatment for febrile neutropenic patients.

To evaluate the effect of adding amikacin (AMK) to imipenem-cilastatin (IPM/CS), we conducted a randomized controlled trial in patients who experienced neutropenia (< 1,000/mm3) and fever (> 38 degrees C) induced by cancer chemotherapy. There were 70 patients who entered the trial; 34 and 36 patients received IPM/CS plus AMK (arm A) and IPM/CS (arm B), respectively. There was no significant difference in patient characteristics between the two groups. Among 67 evaluable patients, 29 of 32 (91%) and 25 of 35 (71%) responded to the antibiotics therapy in arm A and B, respectively, with EORTC criteria (p < .047). Median days of antibiotics administration and of febrile episode over 38 degrees C were not statistically significantly different between arm A and B. There was no patient with severe side effects, such as seizure, and 17 patients (30%) experienced emesis in both groups. These data suggest IPM/CS plus AMK is therapeutically superior to IPM/CS alone in patients with neutropenic fever induced by cancer chemotherapy.

Adult↗

The factor dominating the determination of left ventricular filling varies during the first five days after acute myocardial infarction.

BACKGROUND: Left ventricular diastolic dysfunction may occur after the onset of acute myocardial infarction. Left ventricular diastolic filling dynamics are related to many factors. To evaluate the influence of left ventricular filling pressure on Doppler-derived left ventricular diastolic flow profiles in patients with acute myocardial infarction, we studied serial changes in filling during the first 5 days after the onset of uncomplicated acute myocardial infarction. METHODS: The study population consisted of 14 patients with acute myocardial infarction and 15 normal subjects: Doppler echocardiographic studies (left ventricular transmitral inflow and outflow velocity patterns) were performed on admission, and on the third and fifth days after infarction. Hemodynamic parameters were measured simultaneously using Doppler echocardiography. RESULTS: The E wave was lower, the A wave and A:E ratio were higher, deceleration half time and isometric relaxation time were prolonged, and peak left ventricular ejection flow velocity was lower in myocardial infarction patients than in normal subjects. The E wave and pulmonary capillary wedge pressure were positively correlated on the first and the third day (r = 0.77, P < 0.001, and r = 0.67, P < 0.01, respectively), but not on the fifth day. The E wave and isometric relaxation time were negatively correlated on the fifth day (r = -0.72, P < 0.01), but not on the first and third day. CONCLUSION: Left ventricular filling pressure (preload) was an important mechanism for maintaining left ventricular filling during the first 3 days, but the relaxation of the ventricle began to play a dominant role on the fifth day.

Aged↗

The effect of platelet-activating-factor antagonist TCV-309 on arrhythmias and functional recovery during myocardial reperfusion.

BACKGROUND: We investigated the effects of a platelet-activating-factor antagonist TCV-309, an antagonist of metabolites of ischemia, on arrhythmias and functional recovery during in-situ reperfusion in dogs. METHODS: Open-chest anesthetized dogs were subjected to ligation of the left anterior coronary artery. Ischemia was maintained for 20 min after which reperfusion was allowed. A cardiac surface ECG was recorded continuously with the II limb lead. Monophasic action potential, left ventricular segment shortening measured by sonomicrometer, and left ventricular pressure were recorded simultaneously under atrial pacing (group A, n = 14). In a second group of dogs, TCV-309 (1 mg/kg) was administered before coronary artery occlusion (group B, n = 12). The hearts were constantly paced through the right atrium at 120 beats/min throughout all experiments. Measurements were continuously obtained from before drug administration to 30 min after reperfusion. RESULTS: The 90% repolarization time of monophasic action potentials in group B revealed significant recovery compared with group A until the fifth minute after reperfusion (P < 0.02). Reduction of severe ventricular arrhythmias was observed during reperfusion in group B (P < 0.05). The percentage segment shortening and left ventricular pressure did not differ significantly between the groups. CONCLUSION: The platelet-activating-factor antagonist had beneficial effects on arrhythmias but not on functional recovery during reperfusion after brief coronary artery occlusion in situ in dogs.

Action Potentials↗

A new genus of the order Actinomycetales, Couchioplanes gen. nov., with descriptions of Couchioplanes caeruleus (Horan and Brodsky 1986) comb. nov. and Couchioplanes caeruleus subsp. azureus subsp. nov.

During our taxonomic study of motile actinomycetes, soil isolate RA 335 was found to form a blue substrate mycelium and aerial mycelia with motile arthrospores and to have lysine as the cell wall diamino acid. Actinoplanes caeruleus IFO 13939T (T = type strain) and "Actinoplanes azureus" IFO 13993T are known to have the same characteristics. Therefore, the taxonomic position of these three strains was studied. Aerial mycelia of these strains fragmented during the growth cycle and produced motile spores arranged in chains within the mycelia. Sporangia were not observed. The strains contained menaquinone 9(H4), had guanine-plus-cytosine contents of 69.9 to 72.1 mol%, and had D-glutamic acid, D- and L-serine, glycine, L-alanine, and L-lysine as cell wall amino acids (type A3 alpha). The taxonomic characteristics of these strains differ from those of the previously described motile actinomycetes. On the basis of morphological, physiological, and chemotaxonomic data and the results of DNA-DNA hybridization and comparative 16S rRNA studies, we propose a new genus, Couchioplanes, for these organisms. The type species is Couchioplanes caeruleus comb. nov. (type strain, IFO 13939), which is divided into two subspecies, Couchioplanes caeruleus subsp. caeruleus subsp. nov. (type strain, IFO 13939) for A. caeruleus IFO 13939T and strain RA 335 and Couchioplanes caeruleus subsp. azureus (type strain, IFO 13993) for "A. azureus" IFO 13993T.

Actinomycetales↗

Luteococcus japonicus gen. nov., sp. nov., a new gram-positive coccus with LL-diaminopimelic acid in the cell wall.

A new gram-positive, nonmotile coccus is described. Strains IFO 12422T (T = type strain) and IFO 15385 in the Institute for Fermentation, Osaka, culture collection, which were isolated from soil and water, respectively, have the following chemotaxonomic characteristics: menaquinone MK-9(H4); G + C content of DNA of 67 mol%; and LL-diaminopimelic acid, alanine, glycine, and glutamic acid in a molar ratio of ca. 1:2:1:1 (type A3 gamma). Mycolic acids are not present. The taxonomic characteristics of these organisms are different from those of previously described gram-positive, high-G + C-content cocci. The partial 16S rRNA sequence indicated that IFO 12422T represents a distinct line of descent among gram-positive bacteria with a high G + C content. The name Luteococcus japonicus gen. nov., sp. nov. is proposed. The type strain is strain IFO 12422.

Base Composition↗

Transfer of Propionibacterium innocuum Pitcher and Collins 1991 to Propioniferax gen. nov. as Propioniferax innocua comb. nov.

16S ribosomal DNA analysis indicates that Propionibacterium innocuum is a phylogenetic neighbor of Luteococcus japonicus and that this pair of organisms branches intermediately between the genus Propionibacterium on the one side and the genera Aeromicrobium and Nocardioides on the other side. Phenotypically, strains of P. innocuum differ from species of Propionibacterium by exhibiting aerobic growth and possessing arabinose in the cell wall, they differ from species of Aeromicrobium and Nocardioides by the formation of propionic acid, and they differ from species of Luteococcus in morphology. Consequently, P. innocuum should not be classified with authentic Propionibacterium species, and the transfer of P. innocuum Pitcher and Collins 1991 to a new genus, Propioniferax, as Propioniferax innocua gen. nov., comb. nov. is proposed.

DNA, Bacterial↗

Melanosis Riehl-like facial pigmentation in a Japanese case of AIDS.

An AIDS patient with the cardinal complaint of severe pigmentation on the face is reported. Hyperpigmentation is an unusual symptom of AIDS. This is a Japanese patient who presented melanosis Riehl-like discoloration. The importance of pigmented lesions in patients who have not been given any anti-HIV agents has not been emphasized in the literature.

Acquired Immunodeficiency Syndrome↗

Phase I and pharmacokinetic study of paclitaxel by 24-hour intravenous infusion.

Paclitaxel, a new antitubular agent, appears to be one of the most promising single agents for the chemotherapy of various solid tumors. The primary objectives of this phase I study of paclitaxel using 24-h continuous intravenous infusions were to determine the maximum tolerated dose of paclitaxel administered by this schedule to Japanese patients with solid tumors and to evaluate the pharmacokinetics of paclitaxel. Eighteen patients received one of five doses of paclitaxel, 49.5, 75, 105, 135 or 180 mg/m2. Premedication with diphenhydramine, dexamethasone, and ranitidine was used to prevent acute hypersensitivity reactions. Pharmacokinetic data were obtained from all 18 patients. Dose-limiting toxicities observed at 180 mg/m2 consisted of grade 4 granulocytopenia associated with grade 3 infection. No severe HSRs or cardiac toxicity were detected. Reversible toxicities observed included liver dysfunction, alopecia, peripheral neuropathy and myalgias. Pharmacokinetic studies performed using high-performance liquid chromatography demonstrated that plasma concentrations of paclitaxel increased during the 24-h infusion and declined immediately upon cessation of the infusion with a half life of 13.1-24.6 h (75-180 mg/m2). Less than 10% of paclitaxel was excreted in the urine within 72 h. The peak plasma concentrations and the areas under the concentration-versus-time curves increased linearly with the dose administered. Antitumor activity was observed in one patient with pulmonary metastasis from pharyngeal cancer. Based on these studies a phase II trial dose of 135 mg/m2 administered over 24 h was chosen.

Adolescent↗

A randomized cross-over study of high-dose metoclopramide plus dexamethasone versus granisetron plus dexamethasone in patients receiving chemotherapy with high-dose cisplatin.

We carried out a randomized, single-blind, cross-over trial to compare the antiemetic effect, for both acute and delayed emesis, of granisetron plus dexamethasone (GRN+Dx) with that of high-dose metoclopramide plus dexamethasone (HDMP+Dx). Fifty-four patients with primary or metastatic lung cancer, given single-dose cisplatin (> 80 mg/m2) chemotherapy more than twice, were enrolled in this study. They were treated with both HDMP+Dx and GRN+Dx in two consecutive chemotherapy courses. On day 1, patients experienced a mean of 2.5 (SD = 4.3) and 0.1 (SD = 0.4) episodes of vomiting in the HDMP+Dx and the GRN+Dx groups, respectively (P = 0.0008). Complete response rate on day 1 was 45 and 90% in the HDMP+Dx and the GRN+Dx groups, respectively (P = 0.0001). Patients treated with GRN+Dx had a tendency to suffer more episodes of vomiting than the HDMP+Dx group on days 2-5, but it was not statistically significant. Twenty-four patients (57%) preferred the GRN+Dx treatment and 14 patients (33%), HDMP+Dx. In the HDMP+Dx group, nine patients (21%) had an extrapyramidal reaction, and 5 patients (12%) had constipation that lasted for at least two days. In contrast, no patients had extrapyramidal reactions, and 18 patients (43%) had constipation in the GRN+Dx group (P < 0.01). GRN+Dx was more effective than HDMP+Dx only in preventing the acute emesis induced by cisplatin. An effective treatment for delayed emesis is still needed.

Adult↗

CPT-11: population pharmacokinetic model and estimation of pharmacokinetics using the Bayesian method in patients with lung cancer.

In this study, we aimed to develop a population pharmacokinetic model for CPT-11 and to use the Bayesian method to estimate CPT-11 pharmacokinetic parameters in each of 43 patients who received combined therapy consisting of CPT-11 and etoposide. The group was divided into first and second data sets of 30 and 13 patients, respectively. We developed a population pharmacokinetic model of CPT-11 based on the first data set. The individual pharmacokinetic parameters [area under the concentration curve (AUC) and clearance (CL)] were subsequently estimated by using the Bayesian method on the second data set. Plasma CPT-11 concentrations were measured by high-performance liquid chromatography, and compartmental pharmacokinetic models were fitted by the Bayesian method. The population pharmacokinetic model was developed by using the nonlinear mixed effect model. We selected the volume of the central compartment (Vc), CL, and distribution rate constants (K12, K21) as population pharmacokinetic parameters. The population mean values (CV%) of Vc, CL, K12, and K21 were, respectively, 31.8 (15.7%) liter/m2, 14.1 (27.8%) liter/h/m2, 1.1 (8.4%)/h, and 0.41 (30.3%)/h. Residual intraindividual variability was 22.9%. The optimal sampling regime for estimation of the AUC and CL in using the Bayesian method was the two time points of 1 and 8 h post infusion. The mean predictive error, the mean absolute predictive error, and the root mean squared error were -3.3, 9.4, 3.2% (AUC) and 6.3, 10.0, 3.5% (CL), respectively. We concluded that the AUC and CL of CPT-11 could be estimated from plasma concentrations at two times by using the Bayesian method.

Bayes Theorem↗

Long-term clinical and angiographic follow-up after placement of Palmaz-Schatz coronary stent: a single center experience.

The purpose of this study is to evaluate long-term clinical and angiographic follow-up results after placement of the Palmaz-Schatz stent and angiographic follow-up results of repeat interventions for stent restenosis. From June 1990 to September 1993, the Palmaz-Schatz stent was placed in 411 patients, 427 lesions. Follow-up angiography was performed in 307 lesions at 3-6 months and in 189 lesions at 1 year. Palmaz-Schatz stent implantation resulted in 97.2% procedure success and 94.6% clinical success. Stent thrombosis was observed in 2.2%. Angiographic restenosis rate was 16.3% at 3-6 months study. At 1 year study, "new" restenosis occurred only in 2.3%. Minimal lumen diameter did not change between 6 months and 1 year (2.32 +/- 0.51 mm vs 2.30 +/- 0.54 mm). With the mean follow-up interval of 22 +/- 9 months, cardiac event-free survival was achieved in 74.3%. Among 50 lesions with restenosis, stent restenosis occurred diffusely in 15 lesions (30%), focally inside the stent in 22 lesions (44%) and focally at the stent border in 13 lesions (26%). Repeat interventions were performed in 35 lesions. Restenosis at 3 months after repeat intervention was demonstrated in 9 (32.1%) out of 28 lesions restudied. Restenosis rate after repeat intervention for diffuse stent restenosis was significantly higher than that for focal in-stent restenosis (75% vs 7.7%). Palmaz-Schatz stent implantation was associated with a high initial success rate and a low late restenosis rate. Luminal renarrowing did not occur beyond 6 months up to 1 year.

Coronary Angiography↗

Assignment of the human PAX4 gene to chromosome band 7q32 by fluorescence in situ hybridization.

Of the nine known members of a human paired box-containing gene family (Pax), only PAX4 has not been precisely localized. We screened a cosmid library of human genomic DNA using polymerase chain reaction products for PAX4 as a probe and isolated three positive cosmid clones. Sequence analysis revealed that at least two of them had exon-like sequences and showed extensive homology to Pax-4 in the mouse. These two cosmid clones were mapped to human chromosome band 7q32 by fluorescence in situ hybridization.

Animals↗

Assignment of the human moesin gene (MSN) to chromosome region Xq11.2-->q12.

The human moesin gene (MSN) was mapped to the long arm of the X chromosome. PCR products for the moesin gene cDNA were used as probes to isolate their corresponding cosmid clones. Fluorescence in situ hybridization (FISH) with two of the isolated cosmid probes showed signals at Xq11.2-->q12, whereas four other cosmids showed FISH signals on chromosome 5. Southern blot hybridization, using a PCR product corresponding to the 3' region of the moesin gene cDNA as a probe (probe-3), on one of the two cosmids that produced signals on the X chromosome gave 5.7- and 3.5-kb HindIII fragments. Further Southern hybridization of the DNA from XY, XX, and XXXXX individuals using probe-3 revealed a gene-dose effect of the X chromosome on the size of a 3.5-kb and a 3.0-kb HindIII fragment; in contrast, an invariant 9.8-kb band was present in the DNA of all individuals tested. Sequencing of an exon-intron border revealed that the two cosmids had predicted sequences. These results indicated that the two cosmids contained MSN, and it was consequently assigned to human chromosome region Xq11.2-->q12. These results strongly suggest that MSN may be removed from candidacy for Wiskott-Aldrich syndrome, which has been putatively mapped to Xp11.3-->p11.22.

Chromosome Mapping↗

Effect of gender on the left ventricular diastolic performance during isometric handgrip exercise in normal individuals.

To evaluate the effects of gender and isometric handgrip exercise on left ventricular diastolic function in normal individuals, atrial and rapid filling fraction were investigated using M-mode echocardiography in 35 postmenopausal women and 31 age-matched men. There were no significant differences in heart rate, mean blood pressure, atrial filling fraction, and rapid filling fraction at rest between women and men. When the amount of change in hemodynamic variable during exercise was compared, there were no significant differences in heart rate and mean blood pressure between women and men. But the increase in atrial filling fraction and the decrease in rapid filling fraction were significantly larger in women than in men. These data suggest that left ventricular diastolic function is restricted in postmenopausal women, and left atrial booster pump action is mobilized when afterload is increased during isometric handgrip exercise.

Aged↗

Lipodystrophia centrifugalis abdominalis infantilis occurring in the neck.

We report a Japanese girl with atypical lipodystrophia centrifugalis abdominalis infantilis. The initial lesion developed on the neck as an area of erythema which showed centrifugal spread to the nape, submandibular area and upper breast and central fading to leave a residual depression and purplish brown pigmentation symmetrically. A central depression on the neck, nape, submandibular area and upper breast was surrounded by a distinctive erythematous, slightly elevated and indurated border. Histological examination of the erythematous border revealed inflammatory changes in the subcutaneous fat. Although this patient was affected in an unusual site, we concluded that she had lipodystrophia centrifugalis abdominalis infantilis, because of the overall features of the lesions.

Adipose Tissue↗

Temporary change of compound action potential amplitude after intense sound exposure.

Intense sound induces a temporary or permanent threshold shift. The aim of this study is to make an experimental model for temporary threshold shift (TTS) using guinea pigs. In this study, two kinds of sound exposure were used for inducing a threshold shift in the guinea pig; one of 110 dB SPL at 10 kHz for 10 min and the other of 120 dB SPL at 10 kHz for 5 min. The former condition produced different levels of reduction in compound action potential (CAP) immediately after sound exposure and different steady levels of CAP amplitude after recovery (within 120 min) in 10 guinea pigs. The latter condition produced a total loss of CAP amplitude immediately after sound exposure in 8 of 9 guinea pigs, and this condition continued for 120 min in 7 of the 9 guinea pigs. Additionally, in 2 of 3 guinea pigs which were exposed the sound of 120 dB SPL at 10 kHz for 5 min, the CAP amplitudes were almost the same as those of control animals 1 day after the exposure. One the basis of these results, we consider the sound of 120 dB SPL at 10 kHz for 5 min to be the optimal intensity and frequency of sound and duration of exposure for producing a TTS in the guinea pig.

Acoustic Stimulation↗

Detection of varicella-zoster virus DNA in conjunctivas of patients with herpes zoster.

Detection of varicella-zoster virus (VZV) DNA was carried out in the conjunctivas of 18 patients with herpes zoster by polymerase chain reaction. The rate of VZV DNA detection in conjunctivas was 3/4 in herpes zoster ophthalmicus associated with eruption on the dorsum nasi, 2/5 in herpes zoster ophthalmicus without eruption on the dorsum nasi, 1/2 in herpes zoster with eruption on the cheek and lower jaw, 1/2 in generalized herpes zoster and 0/5 in herpes zoster associated with eruption on the trunk or extremities, respectively. The reason for the detection of VZV DNA in conjunctivas is discussed.

Adult↗

Stimulation by peptide histidine methionine (PHM) of adrenocorticotropin secretion in patients with Cushing's disease: a comparison with the effect of vasoactive intestinal peptide (VIP) and a study on the effect of combined administration of corticotropin-releasing hormone with PHM or VIP.

The effect of peptide histidine methionine (PHM) on ACTH and cortisol secretion was examined in 12 female patients with Cushing's disease and 8 normal women. For comparison, we examined in both groups the effects of vasoactive intestinal peptide (VIP), human (h) CRH plus PHM, and hCRH plus VIP. Each peptide was given as an i.v. bolus in a dose of 100 micrograms, and plasma levels of ACTH and cortisol were measured before and at intervals up to 120 min after the injection. In all normal subjects, hCRH induced significant rises in ACTH (> 50% above the basal) and cortisol (> 20% above the basal), but PHM and VIP were without effect. In this group, hormonal responses after hCRH plus PHM and hCRH plus VIP were statistically indistinguishable from those after hCRH alone. Of the patients with Cushing's disease, 9 (75%) were responsive to hCRH, 5 (42%) were to VIP, and 3 (25%) were to PHM, showing significant increases in both ACTH and cortisol. All the 3 PHM responders were also responsive to VIP, and all the 5 VIP responders were also responsive to hCRH. Interestingly, the responders to VIP and PHM had higher ACTH and cortisol responses to hCRH compared with the nonresponders. In addition, in the patients with Cushing's disease the coadministration of hCRH with PHM or VIP produced additive increases in both ACTH and cortisol. These results suggest that PHM may be another hypothalamic hormone capable of paradoxically stimulating ACTH secretion in at least some patients with Cushing's disease. Although the ACTH-releasing action of PHM appears less potent than those of hCRH and VIP, the possibility was suggested that a certain common mechanism may operate in inducing the ACTH response to these 3 peptides.

Adrenocorticotropic Hormone↗