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Biomedical subjects

K Kitamura

Publications and source records attributed to K Kitamura.

At least 145 records · Page 8Linked to original sources
PubMed2000

Molecular dynamics simulations of bovine cathepsin B and its complex with CA074.

To promote our better understanding of the dynamic stability of the bovine cathepsin B structure, which is characterized by an extra disulfide bond at Cys148-Cys252 from the other species, and of the binding stability of CA074 (a cathepsin B-specific inhibitor), molecular dynamics (MD) simulations were performed for the enzyme and its CA074 complex, assuming a system in aqueous solution at 300 K. The MD simulation covering 400 ps indicated that the existence of a Cys148-Cys252 disulfide bond increases the conformational flexibility of the occluding loop, although the conformational stability of the overall structure is little affected. The structural characteristics of the complex elucidated by X-ray analysis were suggested to be also intrinsic and stable in the dynamic state; the hydrogen bonding/electrostatic interactions between the main and side chains of CA074 and the Sn and Sn' subsites of the enzyme were maintained throughout the MD simulation. Furthermore, the simulation made clear that the binding of CA074 significantly restricted the conformational flexibility of the substrate binding region, especially the occluding loop, of cathepsin B. Statistical analyses during the simulation suggest that the selectivity of CA074 for cathepsin B stems from the tight P1'-S1' and P2'-S2' interactions, assisted in particular by double hydrogen bonds between the carboxyl two oxygens of the CA074 C-terminus and the imidazole NH groups of His110 and His111 residues.

Animals↗
PubMed2000

Labyrinthine involvement and multiple perforations of the tympanic membrane in acute otitis media due to group A streptococci.

We present here three cases of acute otitis media caused by a virulent group A streptococcal infection that rapidly led to deterioration in hearing. Two of the three cases presented with severe sensorineural and mixed hearing loss with multiple tympanic membrane perforations, and the third presented with severe bilateral sensorineural hearing loss following acute otitis media involving group A streptococci. All patients were treated with systemic (piperacillin) and topical antibiotics (ofloxacin ear drops): one patient also received a systemic steroid (betamethasone). Deafness persisted in one patient but in the other two, hearing gradually recovered. Severe cytotoxicity was considered to have occurred in all patients, resulting in multiple perforations of the tympanic membrane and necrosis in the middle ear.

Adult↗
PubMed2000

Atypical aortic coarctation with resistant hypertension treated with axilloiliac artery bypass.

A 68-year-old woman was found to have atypical coarctation of the aorta, accompanied by systolic hypertension of the upper extremities despite administration of five types of antihypertensive drugs. Since the systolic hypertension was resistant to the conventional antihypertensive therapy, axilloiliac artery bypass grafting with a subcutaneous tunnel was performed to alleviate the pressure gradient. Systolic blood pressure was successfully reduced and hypertension was controlled after surgery.

Aged↗
PubMed2000

Health effects of chronic exposure to polychlorinated dibenzo-P-dioxins (PCDD), dibenzofurans (PCDF) and coplanar PCB (Co-PCB) of municipal waste incinerator workers.

A national survey of polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) in emission gases from the municipal waste incinerators in 1997 revealed that the Nose Bika Center was heavily contaminated by PCDF. Ninety-four workers underwent a physical examination, and blood biochemistry, lymphocyte marker, and NK activity studies were carried out, along with blood dioxin measurements. Information on working history, life-style, and dietary habits was obtained by questionnaire and interview. The blood dioxin levels were as follows. The median TEQ of dioxins was 39.7 pg I-TEQ/g lipid, and the range was 13.3 to 805.8. The median 2,3,7,8-TCDD concentration was 3.9 pg TEQ/g lipid, and the range was <1 pg TEQ/g lipid (one case) to 13.4 pg TEQ/g lipid. The median TEQ of coplanar PCB was 10.8 pg I-TEQ/g lipid, and the range was 3.1 to 54.2 pg TEQ/g lipid. The congener-specific distribution was quite similar to that in soil around incinerator and waste in the factory. The relationship between dioxin concentrations and work history in the factory showed that the fluidized incinerator and fly ash treatment areas were high-risk work areas. Correlation analyses between body burden, PCDD/PCDF TEQ, Co-PCB TEQ and various laboratory data showed significant positive correlations between dioxin levels and GGT, total protein, uric acid and calcium, and a negative correlation with Fe. However, these correlations disappeared as a result of multivariate analysis adjusted for age, smoking status, and alcohol drinking. Increased NK activity and lower response to PHA stimulation remained significant even after adjusting for age. History of hyperlipidemia and allergy had significantly increased odds ratios. A study on the risk to other workers in the same type of incinerators is under way. Health effects of chronic exposure mainly to PCDF will be clarified by follow-up.

Adolescent↗
PubMed2000

[Phaeomycotic cyst caused by Phaeoacremonium parasiticum].

Phaeoacremonium parasiticum was identified as the causative agent of a phaeomycotic cyst seen just below the right knee of a 59-year-old healthy woman. She had no history of trauma. Direct KOH examination of the pus aspirated from the subcutaneous nodule revealed abundant mycelia, which were not too deeply brown in color. The nodule was surgically excised, and there was no recurrence during a half year of observation. Tissue section of the excised material revealed rather a large cavity extending from the cutis to the subcutis. The cavity had a thick wall composed of granulomatous tissues. Mycelial and yeast-like fungal elements were seen within the cavity and the granulomatous tissues. A dematiaceous fungus was cultured from both pus and the excised material. The isolates were characterized by a dark green to black colony, unbranched or infrequently branched, brownish conidiophores bearing an aculeate monophialide with a narrow funnel-shaped collarette, and slimy, hyaline, one-celled, ellipsoid to allantoid conidia.

Cysts↗
PubMed2000

[Bilateral facial palsy in a patient with human immunodeficiency virus infection--a case report].

We report a 37-year-old male with bilateral peripheral facial palsy associated with HIV infection. He was serologically tested for HIV and was found to be positive (by Western blot and ELISA). Serum chemistry studies showed elevated HIV RNA and were negative for p24 antigen. The CD4+ count was 533 cells x 10(6) per liter, with a CD4+:CD8+ ratio of 0.47. Since there was no evidence of any other underlying systemic illness, his facial palsy was considered to be secondary to HIV infection.

Adult↗
PubMed2000

[Oral allergy syndrome in patients with Japanese cedar pollinosis].

Patients with pollinosis sometimes complain of oral symptoms (itching and tingling with or without edema of the lips, mouth and tongue) after eating fresh fruits and vegetables. This condition has been termed Oral Allergy Syndrome (OAS). Twenty-three patients with Japanese cedar pollinosis and OAS for fresh fruits and vegetables were included in this study. Their mean age was 31.3 years (range = 5 to 62). The fruits that caused OAS in these patients included melon, apple, peach, and kiwi fruit. Most patients with OAS exhibited hypersensitivity to more than two foods. Specific IgE antibodies to inhaled allergens of mite, Japanese cedar pollen, birch pollen, melon, apple, peach, and kiwi were evaluated using the Pharmacia CAP system. Eleven of the 16 subjects with specific IgE antibodies for birch pollen, did not suffer symptoms during the birch and alder pollen season. In subjects with specific IgE antibodies for fruits, 13 out of 20 patients showed specific IgE antibodies for apple, and 8 out of 9 patients with OAS for apples were also positive for specific IgE antibodies for apples. On the other hand, 17 patients had no specific IgE antibodies for melon, and only two patients and one patient showed specific IgE antibodies for kiwi fruit and peach, respectively. These results suggest that the evaluation of specific IgE antibodies to birch pollen and apple may be useful for diagnosing OAS in patients with Japanese cedar pollinosis.

Adult↗
PubMed2000

[Investigation of the resolution and count recovery coefficients of a whole-body PET scanner (Shimadzu SET-2400W) in 2D and 3D mode image].

UNLABELLED: We measured the resolution and count recovery coefficients (RC) of the SET-2400W whole-body PET scanner (Shimadzu Co., Japan) in the 2D and 3D clinical modes. METHOD: The 3D images were reconstructed by using the full 3D image reconstruction method (3-D reprojection algorithm: 3DRP) and the Fourier rebinning method (FORE). The 2D images were reconstructed with conventional filtered back-projection method (FBP). The measurements of resolution and recovery coefficient were according to JRIA (Japan Radioisotope Association) protocols. RESULTS: The transaxial resolutions of all methods were better than 7 mm FWHM at a radius of 10 cm with 1.25 cm-1 cutoff frequency. The average slice width of 2D FBP, 3DRP and FORE are 5.8 mm, 8.0 mm and 6.8 mm respectively at the center of transaxial field of view. The RC values were measured in a range from 10 mm to 27 mm at 6 cm from the center with the cylindrical and spherical hot area phantoms. In all methods, RC values at 27 mm diameter were nearly 1.0 in both type of hot area. RC values at 10 mm diameter in 2D FBP, 3DRP and FORE of cylindrical hot area were 0.69, 0.72, 0.73 and those of spherical hot area were 0.52, 0.51, 0.53 respectively. CONCLUSION: At the SET-2400W, resolution and recovery coefficient of 3D mode image under the clinical mode showed the value which did not differ from the 2D mode image.

Image Processing, Computer-Assisted↗
PubMed2000

[Efficacy and safety of cefozopran (CZOP) monotherapy and combination therapy with CZOP and amikacin (AMK) for infections accompanying hematological diseases].

We evaluated efficacy and safety of monotherapy with CZOP (1-2 g x 2/day) and combination therapy with CZOP (1-2 g x 2/day) and AMK (200 mg x 2/day) for infections in patients with hematological diseases. Efficacy was evaluated in 71 patients of monotherapy group and 70 patients of combination therapy group. Underlying diseases were mostly leukemia and lymphoma. Infections included sepsis, suspected sepsis, pneumonia and so on. Efficacy in CZOP monotherapy was excellent in 21 patients (31.3%), good in 23 patients (34.3%), fair in 5 patients (7.5%) and the efficacy rate was 65.7%. On the other hand, in combination therapy, each was 14 patients (21.2%), 23 patients (34.8%), 12 patients (18.2%) and the efficacy rate was 56.1%. Side effects such as eruption were noted in 2 patients. Abnormal laboratory findings were noted in 9 patients. All side effects as well as abnormal laboratory findings were minimal. It was concluded that CZOP monotherapy was effective in the treatment of various infections accompanying hematological diseases.

Adolescent↗
PubMed2000

[A case of successful management of nonresectable advanced cholangiocellular carcinoma by intermittent hepatic arterial infusion at home].

An 82-year-old female was referred to our hospital because a 16 x 8 cm tumor detected in her liver by abdominal ultrasonography (echo, hereafter) and CT. The patient was diagnosed as having highly advanced cholangiocellular carcinoma (CCC) by abdominal angiography. Since excision of the tumor was impossible due to the patient's age, a reservoir was indwelled for intra-arterial injection into the liver. Continuous injection of 1,000 mg 5-FU over 24 hours was performed every 2 weeks using a portable disposable pump 70 times. The tumor has been markedly reduced since the start of chemotherapy, with a reduction rate (PR) of 98% over the 3 years until the present. Since the frequency of administration was low, only twice a month, the patient had few side effects despite her old age, and injections could be performed in the outpatient department. Usually, the prognosis for CCC is poor. However, the patient has maintained a good QOL with the periodic intra-arterial injection of the carcinostatic into the liver, and this treatment has had a strong antitumor effect. This chemotherapy is thus considered useful for CCC which can not be resected.

Aged↗
PubMed2000

[Changes in MR imaging appearance of breast cancer after intra-arterial infusion chemotherapy].

The purpose of this study was to evaluate whether the characteristic change in breast cancer related to chemotherapeutic response (CR) and the effect of invasion and toxicity in the skin and pectoralis muscle exist on MR imaging after intra-arterial infusion chemotherapy. A total of 11 patients with histologically proven breast cancer underwent MR study before and after chemotherapy. Changes in images and the dynamic curve-after-chemotherapy were evaluated, including time to maximum signal intensity (SI) and the early phase enhance ratio (EPER) in the tumor. In the tumor, changes in the dynamic curve, time to maximum SI, EPER and necrosis did not correlate with CR, but change in SI on T2-weighted images was suggested to do so. Changes in the dynamic curve and images in the pectoralis muscle and in images on the skin were suggested to correlate with CR. In addition, images changed for the worse in many cases of invasion and toxicity in the pectoralis muscle and in some cases of invasion in the skin. In conclusion, tumors had fewer imaging changes correlating with CR after intra-arterial infusion chemotherapy. Changes for the worse in images of the pectoralis muscle and skin may be useful for the evaluation of invasion.

Adult↗
PubMed2000

[Endoscopic extirpation for benign breast tumor].

Endoscopic extirpation using a fine endoscope and related devices via the extramammary approach (mainly the transaxillary approach) has been applied for benign breast tumors since 1997 in the Second Department of Surgery, Kyushu University. The operative procedures, morbidity, and mortality are presented here. We have treated 37 patients with a mean age of 27.6 years, whose tumors had been diagnosed as benign; average tumor diameter was 3.6 cm. Seven patients had multiple tumors, including 4 with bilateral lesions. The transaxillary approach was chosen in 35 patients and the inframammary approach, which was a procedure in the early phase, was chosen in the remaining 2 patients. Patients with benign tumors can thus avoid direct incision on the breast by endoscopic extirpation via the extramammary approach. We recommend this procedure as a new option instead of direct excisional biopsy for benign breast tumors.

Adult↗
PubMed2000

Histochemical correlates of (15)O-water-perfusable tissue fraction in experimental canine studies of old myocardial infarction.

UNLABELLED: A method has been proposed to quantitate the myocardial water-perfusable tissue fraction (PTF) in the area of hypoperfused asynergic segments using (15)O-water (H2(15)O) and PET. This study investigated the histochemical correlates of PTF (and perfusable tissue index, PTI) in a canine model of old myocardial infarction. METHODS: Myocardial infarction was produced in 12 mongrel dogs, and PET was performed 1 mo later, providing quantitative parametric images of PTF, regional myocardial blood flow (MBF), and extravascular density from H2(15)O, (15)O-carbon monoxide, and transmission datasets. At the end of scanning, the myocardium was sectioned, and the PET images were compared directly with the corresponding myocardial sections. RESULTS: The distribution of tissue necrosis identified by histochemical staining corresponded well with the defect in PTF but not in MBF. PTF agreed with the equilibrium images of myocardial H2(15)O distribution, obtained after injection of a large bolus of H2(15)O. The defect surface area identified on PTF agreed well quantitatively with the morphometric estimates of the surface area of myocardial infarction. PTI agreed with the absolute proportion of histochemically defined normal myocardium (0.87 +/- 0.09 and 0.83 +/- 0.08, respectively; P < 0.01). Both PTF and PTI decreased significantly in segments of myocardial infarction and showed a significant difference between the transmural and nontransmural myocardial infarction. CONCLUSION: The absolute mass and proportion of histochemically defined noninfarcted tissue may be quantitated with PTF and PTI in the area of myocardial infarction segments.

Animals↗