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Biomedical subjects

M Hatakenaka

Publications and source records attributed to M Hatakenaka.

17 recordsLinked to original sources
PubMed2003

Gallium-67 scintigraphy in the diagnosis and management of chronic sarcoid myopathy.

The authors describe a patient with chronic sarcoid myopathy. Except for the presence of left posterior synechia, no other organ involvement was observed. Gallium-67 ((67)Ga) scintigraphy showed many intense nodular uptake areas in both the upper and lower extremities. Treatment with oral prednisolone 30 mg/day resulted in a marked improvement on (67)Ga scintigraphy. This case suggests that (67)Ga scintigraphy is useful for the differential diagnosis of systemic myopathies and also for monitoring the effect of glucocorticoid treatment.

Aged↗
PubMed2001

Expression of the c-myc and c-fos genes as a potential indicator of late radiation damage to the kidney.

PURPOSE: To evaluate proliferative response according to c-myc and c-fos gene expression as an early indicator of late radiation damage to the kidney. METHODS AND MATERIALS: c-myc and c-fos gene expression was measured in the irradiated kidney of C3H/HeSlc mice using reverse transcriptase-polymerase chain reaction (RT-PCR) 24 h after 9, 12, and 15 Gy as well as 2 and 7 days after 15 Gy. In a second experiment, 12 Gy was administered to the right kidney plus the lower half of left kidney. The mice underwent left nephrectomy 24 h after, and the correlation between increased gene expression and elevation of the blood urea nitrogen (BUN) level representing late functional damage was investigated. RESULTS: c-myc and c-fos expression increased in 1 of 10 controls and in 8 of 10 and 7 of 10 mice that received 15 Gy, respectively. Expression increased dose-dependently from 9 to 15 Gy. In mice having an increased BUN level, 7 of 10 and 8 of 10 were positive for c-myc and c-fos, respectively. All 6 mice having an unchanged BUN level were negative for c-fos, while 5 were negative for c-myc. CONCLUSION: Measurement of c-myc and c-fos gene expression is potentially an early indicator of late radiation damage to the kidney.

Animals↗
PubMed2001

MR imaging findings of uterine endometrial stromal sarcoma: differentiation from endometrial carcinoma.

Endometrial stromal sarcoma (ESS) is a rare malignant neoplasm of the uterus. We retrospectively analyzed pelvic MR imaging in 8 cases of ESS to determine the characteristic MR findings of ESS. Magnetic resonance images of 8 cases of ESS were evaluated for findings including the size, margin of the tumor, nodular lesions at the tumor margin, intramyometrial worm-like nodular extension, multiple nodular mass formation, hemorrhage, and necrosis in the tumor. The degree of contrast enhancement was also analyzed. The MR imaging findings of 21 consecutive cases of endometrial carcinoma (EC) were also evaluated and compared with those of ESS. The mean and the standard deviation of the maximum diameter of ESS and EC were 8.80 +/- 4.99 and 3.93 +/- 2.47 cm, respectively. Increased enhancement in at least a part of the tumor was observed in five of the six analyzed ESS cases and in 2 of 12 analyzed EC cases. The irregular margin, nodular lesions at the margin, intramyometrial nodular extension, and multiple nodular mass formation were more frequently seen in cases of ESS than in cases of EC. Magnetic resonance imaging can play a role in both diagnosing ESS as well as in differentiating ESS from EC.

Aged↗
PubMed2001

Effects of aging on muscle T2 relaxation time: difference between fast- and slow-twitch muscles.

RATIONALE AND OBJECTIVES: To determine whether the T2 relaxation time of skeletal muscle is affected by aging and to compare the effects of aging between fast- and slow-twitch muscles in a human study. To investigate the mechanisms of age-related changes in T2 relaxation time in an animal (mouse) study. METHODS: T2 relaxation times of the soleus (slow-twitch, rich in type I fiber) and gastrocnemius (fast-twitch, rich in type II fiber) muscles were examined in 59 healthy human subjects, 22 to 76 years of age, by clinical magnetic resonance imaging. In mice, T2 relaxation times, fat ratios, and extracellular space ratios (extracellular space/intracellular plus extracellular space) of the spinalis (fast-twitch, rich in type II fiber) muscles were also examined (group of 7 old mice, 24-26 months; group of 7 young mice, 8-10 weeks). RESULTS: In the human study, the T2 relaxation time of the gastrocnemius muscle increased significantly with aging (r = 0.53, P < 0.01) while that of the soleus muscle did not. In the animal study, the T2 relaxation time of the spinalis muscle was significantly longer (P < 0.05) and the extracellular space ratio of the spinalis muscle significantly wider (P < 0.01) in old than in young mice. No significant difference in fat ratio was observed between old and young mice. A significant, positive correlation was seen between the extracellular space ratio and T2 relaxation time (r = 0.84, P < 0.01). CONCLUSIONS: The T2 relaxation time of fast-twitch muscle increases with aging, due mainly to increased extracellular space, reflecting age-related type II fiber atrophy.

Adult↗
PubMed2001

Natural killer type 2 bias in remission of multiple sclerosis.

Multiple sclerosis (MS) is an autoimmune disease characterized by clinical relapse and remission. Because of the potential role of natural killer (NK) cells in the regulation of autoimmunity, we have examined cytokine profile and surface phenotype of NK cells in the peripheral blood of MS. Here we demonstrate that NK cells in the remission of MS are characterized by a remarkable elevation of IL-5 mRNA and a decreased expression of IL-12Rbeta2 mRNA, as well as a higher expression of CD95. Moreover, the NK cells from MS in remission produced much larger amounts of IL-5 than did those from controls after stimulation with phorbol myristate acetate (PMA) and ionomycin. These features are reminiscent of those of NK type 2 (NK2) cells that can be induced in a condition favoring functional deviation of T cells toward Th2. Remarkably, the NK cells lose the NK2-like property when relapse of MS occurs, but regain it after recovery. We also found that NK2 cells induced in vitro inhibit induction of Th1 cells, suggesting that the NK2-like cells in vivo may also prohibit autoimmune effector T cells. Taken together, it is possible that NK cells play an active role in maintaining the remission of MS.

Adult↗
PubMed2001

[A patient with myopathy due to preclinical Cushing syndrome].

A 57 year-old man with a history of diabetes mellitus was admitted to our hospital for the complaint of slowly progressive muscle weakness involving proximal limbs and head dropping. His serum CK level was within normal range, and muscle biopsy showed no inflammatory changes. To rule out myasthenia gravis, computerized tomography was done for the detection of thymoma, and detected an adrenal tumor in stead. He was not over-weighted, and his morning plasma levels of ACTH and cortisol were within normal ranges. Additional hormonal examinations revealed daily autonomous hypersecretion of cortisol. He received diagnosis of preclinical Cushing syndrome. After resection of the tumor, muscle weakness improved and his diabetes mellitus was controlled better. The muscle symptoms seem to be related with steroid myopathy. Preclinical Cushing syndrome should be included as a differential diagnosis for myopathy of unknown etiology.

Adrenal Gland Neoplasms↗
PubMed1999

Penetrating atherosclerotic ulcer at the proximal aorta complicated with cardiac tamponade and aortic valve regurgitation.

A 56-year-old man had a penetrating atherosclerotic ulcer originating in the proximal ascending aorta, which is an unusual case of penetrating aortic ulcer complicated with the aortic valve regurgitation and cardiac tamponade. This hemodynamically unstable patient was successfully treated by conservative management to control his blood pressure and was also monitored closely with follow-up imaging studies.

Aortic Diseases↗
PubMed1997

Acute suppurative perithyroiditis: MR findings.

We report the MR findings in two cases of acute suppurative perithyroiditis. MR has the advantages over other imaging modalities of being able to distinguish areas of inflammation from adjacent normal tissue and of allowing imaging in planes which more accurately demonstrate the extent of the lesion. MR imaging is one of the most useful methods to evaluate this entity.

Acute Disease↗
PubMed1997

Effect of caffeine on the mental calculation.

The double blind study of the effect of caffeine on the mental calculation has been carried out every year in the undergraduate course of Clinical Pharmacology, Medical School, Kyushu University. The results obtained from 1980 to 1996 are summarized and evaluated.

Adult↗
PubMed1996

[Chest wall reconstruction using polyester mesh].

From January 1987 through December 1994, we performed chest wall reconstruction using the polyester mesh in 15 patients with lung cancer, 11 with empyema after open drainage, 8 with chest wall tumor and 1 with radiation dermatitis and costal chondritis. Twenty five patients were resected 3 or more ribs. Chest wall defects were reconstructed with the polyester mesh covered with Gore-Tex soft tissue patch. Twenty two cases passed more than a year without signs of infection and follow-up averaged 27.6 months. Polyester mesh was removed due to bronchial fistula (3 cases), deformities (3 cases) and abscess formation (1 case). In these cases, polyester mesh was well incorporated and had no foreign body change. In conclusion, the polyester mesh seems to be a dependable prosthetic material for chest wall reconstruction.

Adult↗
PubMed1994

Phosphatidic acid induces the release of beta-glucuronidase but not lactoferrin from electropermeabilized human neutrophils.

We studied the degranulation reaction of electropermeabilized human neutrophils induced by 1,2-didecanoyl-3-sn-phosphatidic acid (PA10). PA10 dose-dependently induced the release of beta-glucuronidase, an enzyme of azurophil granules, but did not induce the release of lactoferrin, a protein of specific granules. The enzyme release by PA10 absolutely required Ca2+, ATP, and Mg2+ and the concentrations for the half-maximal response were 2.5 microM, 60 microM, and 0.25 mM, respectively. Although Ca2+ alone at concentrations higher than 10 microM induced the release of both beta-glucuronidase and lactoferrin, the extents of the release were far less than that of the beta-glucuronidase release by PA10. Phorbol myristate acetate (PMA) and 1-oleoyl-2-acetyl-sn-glycerol induced the release of lactoferrin alone at concentrations of Ca2+ below 0.5 microM while they induced the release of both beta-glucuronidase and lactoferrin at higher Ca2+ concentrations, indicating that the degranulation induced by PA10 is not mediated by diacylglycerol which might be formed from PA. The degranulation reactions induced by PA10 and PMA were dose-dependently inhibited by staurosporine and calphostin C, protein kinase C inhibitors, although no direct activation of protein kinase C by PA10 was observed. The extent of the beta-glucuronidase release by PA10 was not enhanced by the addition of PMA. Propranolol, which inhibits protein kinase C as well as phosphatidic acid phosphohydrolase, strongly inhibited the degranulation reactions induced by PA10 and PMA. Ethanol, a metabolic modulator of phospholipase D, and cyclic AMP did not affect the degranulation reactions by PMA and PA10.(ABSTRACT TRUNCATED AT 250 WORDS)

Calcium↗
PubMed1993

[The changes in Ca(2+)-sensitivity of rabbit skeletal myofibrillar ATPase activity under various conditions].

Effect of the composition of the reaction mixture on the Ca(2+)-sensitivity of myofibrillar ATPase of rabbit skeletal muscle was investigated. The Ca(2+)-concentrations necessary for the half maximum ATPase activation were 2.95 x 10(-6) M at 50 mM KCl, 4.37 x 10(-6) M at 90 mM KCl and 5.25 x 10(-6) M at 130 mM KCl. Thus the Ca(2+)-sensitivity was definitely lower at higher KCl concentrations. The Ca(2+)-sensitivity was about 2 times higher at pH 7.3 (pCa50 5.65) compared to the Ca(2+)-sensitivity at pH 6.8 (pCa50 5.36). The change in the Mg-ATP concentration between 0.5 mM and 3.5 mM, did not significantly affect the Ca(2+)-sensitivity of myofibrillar ATPase, but affected biphasically the maximum ATPase activity. These change in the Ca(2+)-sensitivity at various conditions is considered to be due mainly to the property of troponin C, the Ca(2+)-receptive protein of myofibrils.

Adenosine Triphosphatases↗
PubMed1992

Effect of removal and reconstitution of troponins C and I on the Ca(2+)-activated tension development of single glycerinated rabbit skeletal muscle fibers.

The effect of troponin T treatment on the Ca(2+)-activated tension of single glycerinated rabbit skeletal muscle fibers was examined. The tension of the fiber was completely desensitized to Ca2+ by incubation in a solution containing an excessive amount of troponin T and reached a level of about 70% of the maximum tension of the control fiber. SDS/PAGE showed that most of troponins C and I was removed from the fiber by troponin T treatment. During the course of troponin T treatment, the cooperativity of Ca2+ activation (Hill coefficient) was decreased while pCa at half-maximal Ca(2+)-sensitive tension (pK) increased. Using the 26-K fragment of troponin T, the study indicated that the removal of troponins C and I was due to the replacement of the troponin C.I.T complex in the myofibrils of the fiber with the added troponin T. The troponin-T-treated fiber was again sensitized to Ca2+ by the addition of troponin C.I. The removal of troponin C by treatment with trans-1,2-cyclohexanediamine-N,N,N',N'-tetraacetic acid did not change the minimum tension of the fiber, from which troponin C.I was partially removed by troponin T treatment, but it decreased the height of maximum tension with a concomitant decrease in the Hill coefficient as well as a decrease in pK. The above findings suggested that pK is determined by the balance between two opposite actions through troponins C and I, while the extent of cooperativity of Ca2+ activation seemed to be related mainly to the content of troponin C.

Animals↗
PubMed1991

Replacement of three troponin components with cardiac troponin components within single glycerinated skeletal muscle fibers.

The tension of single glycerinated rabbit skeletal muscle fiber was desensitized to a Ca(2+)-concentration after treatment with an excessive amount of bovine cardiac troponin T and reached a level of about 70% of the maximum tension of the untreated fiber. A SDS-gel electrophoretic examination indicated that troponin C.I.T complex in the fiber was replaced with the added cardiac troponin T. The Ca(2+)-sensitivity of the tension of the troponin T-treated fiber was then recovered by the addition of bovine cardiac troponins I and C. The rabbit skeletal muscle fiber thus hybridized with bovine cardiac troponin C.I.T showed the same cooperativity of Ca(2+)-activation as the cardiac muscle.

Animals↗
PubMed1989

[Development and clinical application of ICG clearance meter].

We have developed a finger-piece method that can indicates an accurate concentration of ICG based on the two wavelength spectrophotometry. Seventy-eight subjects were evaluated by this new method. The ICG clearance curve obtained from ICG clearance meter showed a rapid increase 20 or 40 seconds after the bolus injection. The curve decreased gradually, and increased again at 60 or 70 seconds. Plasma disappearance rate (PDR) by this method (XK ICG) was calculated by the at least square method from 600 data obtained from 5 to 15 minutes after the injection. There was a significant correlation between conventional PDR (KICG) and new method (XK ICG) also. We assume that this method have a possibility to discover new aspect of pharmacokinetics of ICG.

Adolescent↗
PubMedDate not supplied

Use of immunocytochemistry on urinary sediments for the rapid identification of human polyomavirus infection. A case report.

The application of immunocytochemistry in urinary cytology for the identification of a human polyomavirus infection is described. The Papanicolaoustained slides of voided urine specimens of a 26-year-old man undergoing steroid therapy showed many inclusion-bearing epithelial cells. After subsequent destaining of the same slides, the presence of human papovavirus antigen in the nuclei of infected exfoliated cells was demonstrated by immunocytochemical staining with simian virus 40 antiserum and peroxidase. Papovaviruses were also detected by electron microscopic study of the smears, confirming the diagnosis of a human polyomavirus infection. The use of immunoperoxidase studies proved to be advantageous for the rapid cytodiagnosis of human polyomavirus infection in the urinary specimens in this case; such studies may be of particular value in equivocal cases to prove or disprove the viral nature of morphologic changes observed in routine preparations.

Adult↗