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Biomedical subjects

T Koizumi

Publications and source records attributed to T Koizumi.

At least 55 records · Page 3Linked to original sources

[Dental treatment in the north area of Ishigaki Island in Okinawa].

Dental treatment and oral health care were performed on inhabitants in the north area of Ishigaki Island in Okinawa. There are no dentists in the area at present. One hundred sixty-six patients received treatment taking 528 man-days, during the period from November 9 to December 8, 2000. The area has 2 primary schools and 1 junior high school. The average DMFT of the children in the primary schools was 1.31, and in the junior high school it was 4.98. Compared with Japanese national survey data, the children in the area had a higher DMFT. Among the treatment procedures, the rate of conservative treatment was 62%, most of which was composite resin filling. Preventive measures for dental disease were offered to the inhabitants by means of topical fluoride application or oral health education. The period of this promotion was too short to perform complete dental treatment and to prevent caries and periodontal disease. It seems that primary prevention and higher dental hygiene education are needed for inhabitants in no-dentist areas, because the inhabitants do not have access to dental service easily.

Community Dentistry↗

[Treatment of phimosis with betamethasone ointment in children].

OBJECTIVE: We evaluated the efficacy of betamethasone ointment in the treatment of childhood phimosis and determined the most effective concentration of betamethasone. MATERIAL AND METHODS: Between August 1996 and May 2000, 69 patients (median age 3.0, range 0-12) presented to our department with severe phimosis (grade 4, Tsugaya's classification), and were enrolled in this study and treated with betamethasone ointment for 4 weeks. The ointment was applied on the narrowed preputial skin twice a day by parents. During the first week, parents were asked not to retract the foreskin. After this period, parents were encouraged to retract the foreskin gently and without intense tension. The concentration of betamethasone were 0.12%, 0.05% and 0.025%. If the patients become to be able to retract foreskin satisfactory, we consider the state as complete response. If he become to be able to retract to allow partial exposure of the glans, we consider the state as partial response. We compared the efficacy among each of the concentrations, and at 3 months after the end of the treatment, we also assessed the adverse effects and recurrence. RESULTS: The overall success rate was 85.5%. Success rates with 0.12%, 0.05% and 0.025% ointment were 96.8%, 82.8% and 55.6%, respectively (p = 0.0001). The 0.12% ointment was most effective. Recurrence was observed in 3 patients (4.3%). No adverse effects were observed in any of the patients. CONCLUSIONS: Treatment with betamethasone ointment is very effective, easy and safe. We recommend betamethasone ointment as the first treatment of choice for childhood phimosis.

Betamethasone↗

[Comparison of digital subtraction angiography, CT angiography, and ultrasonic Doppler examination in the evaluation of penile arterial lesions].

BACKGROUND: CT angiography reconstructed by a multidetector-row helical CT scanner is a newly developed form of imaging. We compared CT angiography and ultrasonic Doppler examination with digital subtraction angiography (DSA) in the diagnosis of arterial lesion. METHOD: Eighteen patients with arteriogenic erectile dysfunction (ED) underwent color Doppler study, DSA, and CT angiography after providing informed consent. The CT angiography images were obtained by a multidetector-row helical CT scanner, Asteion TSX021A (TOSHIBA). We injected prostaglandin E1 into the penile cavernous body, and then rapidly infused nonionic contrast medium into the antecubital vein. DSA and CT angiography images of the bilateral internal pudendal arteries and cavernous arteries were examined for stenotic lesions or occlusion. We also compared the peak systolic blood flow velocity in the cavernous artery measured by color Doppler ultrasound with CT angiography and DSA. RESULTS: The CT angiography and color Doppler studies were performed on an outpatient basis, but DSA required hospitalization. In the 36 internal pudendal arteries, DSA represented 22 normal arteries and 14 stenosis or occlusions. CT angiography showed 15 normal arteries and 21 occlusions. For the diagnosis of stenosis or occlusion in the internal pudendal artery, the CT angiography image had a good agreement, with a sensitivity of 1.00, specificity of 0.68, and accuracy of 0.81. For diagnosis in the cavernous artery, CT angiography image also showed a good agreement with DSA; however, the quality of the images of fine arteries was better in the DSA images. The inferior view and internal view of the pelvis in CT angiography were helpful for visualizing the internal pudendal artery, especially at the pubic bone. There was insufficient correlation between peak systolic blood flow velocity and DSA findings. There were no serious complications involved in either examination. CONCLUSIONS: CT angiography has not yet reached the same level as DSA in the evaluation of fine arteries. However, CT angiography can produced images sufficient for the diagnosis of arteriogenic ED with some advantages. We believe that with improvement, CT angiography will become an adequate replacement for DSA in the diagnosis of penile arterisl lesion.

Adult↗

Age-related changes in skin permeability of hydrophilic and lipophilic compounds in rats.

The effect of age on intact and stripped skin permeability of lipophilic (ketoprofen and isosorbide dinitrate) and hydrophilic permeants (deuterium oxide and diclofenac sodium) was investigated using STD: Wistar male rats aged 5 to 180 days. The permeability of permeants through intact skin increased with increasing lipophilicity of the permeants at each age, indicating that the permselective property of rat skin is revealed even at 5-days-old. The permeability coefficients through intact skin decreased with increasing age, and the extent of these decreases was higher for lipophilic permeants than that for hydrophilic permeants. On the other hand, the stripped skin permeability of permeants was almost the same at each age, and with aging each permeability coefficient through stripped skin decreased up to 21 days, dramatically during 21-90 days and then gradually again to 180 days. The thickness of the stratum corneum and stripped skin increased according to age with faster growth during 21-90 days. The reciprocal of the mean thickness of stratum corneum and stripped skin correlated well with intact skin and stripped skin permeability (r > 0.9), respectively. These results clarified that the permselectivity of rat skin against lipophilicity of permeant exists at the latest from 5 days after birth. In addition, it is speculated that the thickness of skin is a large factor in the decrease of its permeability with age.

Aging↗

Stereoselective pharmacokinetics and pharmacodynamics of organic nitrates in rats.

Plasma concentration and vasodilating effect after i.v. bolus injection of stereoisomeric organic nitrates were evaluated. Pharmacokinetics of mononitrates was analyzed with a linear one-compartment model. The apparent volumes of distribution were almost identical, but systemic clearances were different among stereoisomers. The concentration data after dinitrate administration could be described based on a two-compartment model with elimination only from the central compartment via metabolism to mononitrate, and then mononitrate-dependent metabolic clearance was estimated. In the vasodilation by mononitrate administered intravenously, the maximum effect was not observed. The reduction of mean arterial pressure from baseline level was related to plasma concentration with a log-linear model. The pharmacological effect following dinitrate dosing was analyzed by a sigmoidal Emax model assuming a simple additive effect of dinitrate and mononitrate. Although almost the same Hill's constant and maximum effect (Emax) values were estimated, the concentrations required to produce 50% of Emax (EC50) differed among stereoisomers. The clearance and EC50 values of stereoisomers with nitrate group at the exo position were generally higher than those with the same group at the endo position. This suggests that the stereostructure of organic nitrates controls the vasodilator potency and duration of action.

Animals↗

[Two cases of pulmonary disease with perinuclear anti-neutrophil cytoplasmic antibody].

We encountered two cases of perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA). The first was a case of idiopathic interstitial pneumonia diagnosed in a 73-year-old man since 1998. He was admitted to our hospital because of renal failure and anemia. The serum level of p-ANCA on admission was 264 EU, and specimens obtained by percutaneous renal biopsy showed crescentic glomerulonephritis and vasculitis due to p-ANCA. He was treated with prednisolone pulse therapy and prednisolone (PSL), however interstitial pneumonia occurred during PSL tapering. We treated him for pulmonary fibrosis with plasmapheresis, methylprednisolone (mPSL) and cyclophosphamide (CPA), which suppressed the progress of the interstitial pneumonia. The second case was one of massive pulmonary hemorrhage in a 68-year-old man who was admitted to our hospital. Physical examination revealed anemia: the laboratory data, renal failure; and the serum level of p-ANCA was elevated to 611 EU. The specimens obtained by percutaneous renal biopsy showed crescentic glomerulonephritis and vasculitis. The renal failure was not improved by PSL, but, together with the inflammation, responded to the combination of PSL and CPA. However, both patients died of serious infection. They were regarded as compromised patients because of the therapy mentioned above. No standard therapy has been established against p-ANCA positive pulmonary disease with renal failure. The treatment should control the progression of interstitial pneumonitis and pulmonary hemorrhage. It is important to consider the possibility of serious infection.

Aged↗

[Brown-Séquard syndrome and cervical CSF leakage due to a knife injury: a case report].

We report a case of Brown-Séquard syndrome and cervical CSF leakage caused by a knife injury. A 34-year-old man was involved in a fight and was stabbed on his occiput and back with a knife. Neurological examination on admission showed right hemiparesis, right hemihypesthesia and left hemihypalgesia, indicating Brown-Séquard syndrome. Furthermore, cerebrospinal fluid was leaking from the occipital stab wound. Head CT scan showed massive accumulation air in the subarachnoid space. Cervical MRI showed that the injury tract reached to the space between the occipital bone and the atlas. One week after admission, suboccipital craniectomy and duraplasty were performed because of continuous CSF leakage. Although, the CSF leakage recurred due to the wound infection, it disappeared naturally as the patient's general condition improved. Follow-up MRI studies demonstrated the cervical spinal lesion as hyperintensity on T2WI, which localized at the right side of the spinal cord. The patient's hemiparesis gradually improved and he underwent rehabilitation. Spinal cord injury due to a stab wound by a knife is rare in Japan. In this case, we suppose that the mechanism of spinal cord injury was due to direct injury by a knife avoiding the lateral corticospinal tract because his right hemiparesis obviously improved.

Adult↗

[A case of primary leiomyosarcoma of the pulmonary artery].

A 74-year-old woman was admitted to our hospital because of right chest pain. The chest radiograph showed right hilar pulmonary artery dilatation. A mass exhibiting low intensity in T1-weighted images and high intensity in T2-weighted images was disclosed in the right pulmonary artery. Because of its clinical course and the MRI findings, the mass was thought to be tumorous tissue, and so pneumonectomy was performed. Leiomyosarcoma was diagnosed from the histological findings. Primary artery sarcoma is rare and the prognosis is considered to be extremely poor. The patient was successfully treated and had a good clinical outcome.

Aged↗

[A case of renal cell carcinoma complicated with interstitial pneumonitis, complete A-V block and pleural effusion during interferon-alpha therapy].

A 76-year-old man with postoperative renal cell carcinoma accompanied by multiple lung metastasis was being treated with recombinant interferon-alpha. After administration of 3 MU/day on 3 days/week for 1 month, he complained of headache and tinnitus. During continuous treatment for 3 months, he complained of appetite loss, low-grade fever and dyspnea. He was then referred to our Department of Internal Medicine. Electrocardiography indicated a complete A-V block, and chest radiography (CXR) showed a reticular shadow in both lower lung fields and bilateral pleural effusion. Chest computed tomography (CT) indicated subpleural emphysematous changes, multiple nodules, consolidation shadow with ground glass opacity in both lower lobes, and bilateral pleural effusion. The findings in the bronchoalveolar lavage (BAL) fluid included increases in the numbers of lymphocytes and eosinophils. We reached a diagnosis of interferon-alpha-induced pneumonitis on the basis of the patient's clinical course, and the CXR, chest CT and BAL fluid findings. Treatment with methylprednisolone pulse therapy for 3 days and then administration of prednisolone for 1 month resulted in marked improvement in the complete A-V block and interstitial pneumonitis. At day 7 after discontinuation of prednisolone, the serum level of C-reactive protein increased, and CXR showed bilateral pleural effusion. We therefore believe that the pleural effusion was probably also induced by interferon-alpha. Interferon is an effective drug for chronic hepatitis C and malignant diseases. Many complications have been reported during interferon therapy. However, although these complications, such as interstitial pneumonitis, complete A-V block and pleural effusion, have rarely been reported, careful attention is required during interferon therapy in case any appear.

Aged↗

Effects of lecithinized superoxide dismutase and a neutrophil elastase inhibitor (ONO-5046) on hyperoxic lung injury in rat.

Reactive oxygen and neutrophil metabolites have been implicated in the development of hyperoxic lung injury. We determined the protective effects of either a superoxide dismutase or neutrophil elastase inhibitor and the combination of both agents on the development of hyperoxic lung injury in rats. Two drugs (lecithinized superoxide dismutase and ONO-5046) were used in the present study. Lecithinized superoxide dismutase, a lecithin derivative bound to recombinant CuZn superoxide dismutase, has a higher affinity for cells such as polymorphonuclear leukocytes and endothelial cells than recombinant human superoxide dismutase. N-[2-[4-2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl]¿ aminoacetic acid (ONO-5046), a specific neutrophil elastase inhibitor, which was developed as a low-molecular weight inhibitor, showed protective effects against various lung injuries. Rats were exposed to over 90% oxygen for 72 h, and bronchoalveolar lavage was performed to evaluate the permeability and neutrophil accumulation in the lungs. Rats were treated with lecithinized superoxide dismutase (30,000 U/day, intravenously n=7) or ONO-5046 (10 mg/kg, intramuscularly twice a day, n=7) or a combination of both drugs (n=7). Albumin concentration and neutrophil counts in bronchoalveolar lavage fluid were compared between animals with and without drug treatment. Either lecithinized superoxide dismutase or ONO-5046 treatment significantly decreased albumin concentration and neutrophil counts in bronchoalveolar lavage fluid compared to those in the animals of the hyperoxia-alone group (n=9). However, albumin leakage and neutrophil accumulation in the rat lung treated with combined agents were identical to that of either the lecithinized superoxide dismutase or ONO-5046 treatment. These findings suggest that lecithinized superoxide dismutase and ONO-5046 are useful drugs to protect against hyperoxic lung injury in rats. However, there were no additive effects by the combination in preventing hyperoxic lung injury.

Albumins↗

Ion pair skin transport of a zwitterionic drug, cephalexin.

The ion pair skin transport of cephalexin was investigated using various counter ions and solvents. The permeability of cephalexin was enhanced by 1-alkylsulfonates (ASs) at pH 3.0 and by tetraalkylammoniums (AAs) at pH 7.0; the enhancing ratio increased with the number of carbon atoms in their alkyl chains. The corresponding effects of these additives were observed on the partitioning of cephalexin. Most of the additives did not affect the skin transport of D-mannitol and cortisone. These results suggest that the enhanced transport of cephalexin results from the ion pair formation with additives. Although ASs increased the partitioning of cephalexin above that of AAs, the transport enhancement effect of ASs was lower than AAs having the same number of carbon atoms in their alkyl chains, indicating higher diffusivity of the ion pairs with AAs in skin. Moreover, the transport enhancement by AAs increased even more when ethanol-buffer solutions were used as solvents. The conductivity measurement of dissolving solutes in donor solvents showed that the further enhancement might be caused by the increasing ion pair formation in solvents with low dielectric constants. To obtain the maximum enhancement of skin transport of zwitterionic drugs via ion pair concept, one should select a counter ion having high lipophilicity and small volume, and a solvent with suitable pH and low dielectric constant.

Animals↗

Chitosan citrate as film former: compatibility with water-soluble anionic dyes and drug dissolution from coated tablet.

Chitosan citrate solution containing 25% w/w propylene glycol was prepared and tested for its compatibility with some water soluble anionic dyes. The immiscibility between erythrosine, ponceau 4R, sunset yellow or tartrazine solutions and chitosan citrate solution was evident. The Fourier transform-infrared spectra revealed charged interaction between anionic dye and chitosan. Brilliant blue and green FS at concentration of 0.02-1.00% w/w polymer could be miscible with chitosan citrate solution due to the decrease in charge interaction by the positive charge on molecule of brilliant blue, which was also the composition in green FS. Propranolol HCl tablets coated with these colored film-coating solutions exhibited good appearance and no color migration. Drug dissolution from coated tablets was pH dependent, corresponding to the ability of chitosan to protonate in the medium. Color incorporation slightly retarded drug dissolution in acidic medium. Drug dissolved from coated tablet colored with brilliant blue was faster than from that colored with green FS. This was because brilliant blue had positive charge and more SO(3)H groups on its molecular structure, and exhibited higher water solubility. Accelerated condition could alter dissolution characteristics, and the Td+t(0) value from curve fitting between the dissolution profiles and Weibull equation was increased. However, drug dissolution from freshly prepared coated tablets, coated tablets after exposure to accelerated condition and after storage at room temperature for 12 months conformed to the monograph in USP XXIII.

Chitosan↗

Hypoxia-induced pulmonary blood redistribution in subjects with a history of high-altitude pulmonary edema.

BACKGROUND: Pulmonary hypertension has been suggested to play an important role in development of high-altitude pulmonary edema (HAPE), and individual susceptibility has been suggested to be associated with enhanced pulmonary vascular response to hypoxia. We hypothesized that much greater pulmonary vasoconstriction would be induced by acute alveolar hypoxia in HAPE-susceptible (HAPE-s) subjects and that changes in pulmonary blood flow distribution could be demonstrated by radionuclide study. METHODS AND RESULTS: We performed ventilation-perfusion scintigraphy in 8 HAPE-s subjects and 5 control subjects while each was in the supine position and acquired functional images of pulmonary blood flow and ventilation under separate normoxic and hypoxic (arterial oxygen saturation, 70%) conditions. We also measured acceleration time/right ventricular ejection time (AcT/RVET) with Doppler echocardiography under each condition in both groups. Moreover, we assayed human leukocyte antigen (HLA) alleles serologically in the HAPE-s group. Pulmonary blood flow was significantly shifted from the basal lung region to the apical lung region under hypoxia in HAPE-s subjects, although no significant change in regional ventilation was observed. With Doppler echocardiography, HAPE-s subjects showed increased pulmonary arterial pressure during hypoxia compared with control subjects. The magnitude of cephalad redistribution of lung blood flow was significantly higher in the HLA-DR6-positive than in HLA-DR6-negative HAPE-s subjects. CONCLUSIONS: These findings suggest that acute hypoxia induces much greater cephalad redistribution of pulmonary blood flow that results from exaggerated vasoconstriction in the basal lung in HAPE-s subjects. Furthermore, pulmonary vascular hyperreactivity to hypoxia may be associated with HLA-DR6.

Altitude Sickness↗

Quantitation of minimal residual disease in t(8;21)-positive acute myelogenous leukemia patients using real-time quantitative RT-PCR.

t(8;21) is one of the common chromosomal translocations in acute myelogenous leukemia (AML). Using a recently developed real-time quantitative polymerase chain reaction (PCR) system, we analyzed the minimal residual disease (MRD) in bone marrow samples from seven AML patients with t(8;21) at different time points during the clinical courses of their disease. Four of these patients received chemotherapy and allogenic bone marrow transplantation (allo-BMT), and the other three were treated with chemotherapy alone. Two of the patients that received allo-BMT suffered a relapse. In these patients, the levels of AML1-MTG8 mRNA expression were shown to quantitatively increase. After re-induction chemotherapy and donor lymphocyte infusion therapy, AML went into remission and the expression levels decreased. In the other two patients receiving allo-BMT, the disease went into remission and the level of AML1-MTG8 mRNA expression remained under the detectable range. The other three patients received several courses of chemotherapy, without allo-BMT, and all of them clinically reached the hematological and cytogenetic remission state. However, there were low but detectable levels of MRD in their bone marrow samples. These results suggest that the real-time quantitative PCR assay is very useful for the monitoring of MRD and detecting an early relapse. This assay may also be useful in determining the quantitative difference in myelo-ablative activity between the chemotherapy alone and chemotherapy in conjunction with allo-BMT.

Adult↗

Double cancer (lung and colon cancer) that showed complete remission with irinotecan and cisplatin combined chemotherapy.

We report a rare case of double (colon and lung) cancer which showed complete remission with chemotherapy with irinotecan (CPT-11) and cisplatin (CDDP). The patient was a 67-year-old man who was diagnosed as having double cancer (stage IIIb pulmonary adenocarcinoma and stage 0 [or 1] well-differentiated adenocarcinoma of the ascending colon). Two courses of chemotherapy (CPT-11, 60 mg/m2, days 1 and 8; CDDP, 30 mg/m2, days 1 and 8) were performed. The combination therapy of CPT-11 and CDDP was very effective. In Japan, there have been few published reports describing the use of CPT-11 for the treatment of gastrointestinal cancer. We think that the use of CPT-11 in gastrointestinal cancer is promising.

Adenocarcinoma↗

Trophoblastic cells expressing human chorionic gonadotropin genes in peripheral blood of patients with trophoblastic disease.

We attempted to identify the cells expressing alpha and beta subunits of human chorionic gonadotropin (hCG) in the peripheral blood of patients with trophoblastic disease and normal pregnant women by using reverse transcriptase polymerase chain reaction (RT-PCR) and Southern blot. By this method, the mRNAs of hCG alpha and hCG beta were detected in the peripheral blood mononulear cells (PBMNC) from 3 of 7 hydatidiform mole (mole) and 1 of 4 choriocarcinoma patients as well as from normal pregnant women during the first trimester. None of the mRNAs of hCG subunits was detected in the PBMNC from healthy male and nonpregnant healthy women examined. The expression of hCG alpha and hCG beta in patients with trophoblastic disease and normal pregnant women almost correlated with their plasma levels of intact hCG. The present study indicates that the cells expressing hCG alpha and hCG beta, which virtually represent trophoblasts, are circulating in the peripheral blood of patients with trophoblastic disease as well as of normal pregnant women.

Blotting, Southern↗

Pulmonary artery remodeling modifies pulmonary hypertension during exercise in severe emphysema.

To clarify the relation between the vessel remodeling and the physiology of pulmonary circulation in chronic obstructive pulmonary disease (COPD), we studied the pulmonary hemodynamics at rest and during exercise (25W) and the morphology of pulmonary arteries with external diameters of 100-200 microm in ten patients with severe emphysema. The wall thickness (WT) was defined as the intima plus media. The percent WT of the external diameter (% WT) in emphysema (36.0 +/- 4.3%) was significantly increased compared with that (22.6 +/- 3.3%) in five control lungs. The % WT was not related to pulmonary arterial pressure (Ppa) at rest, but was highly correlated with exercise Ppa (r = 0.721, P = 0.02) and with deltaPpa (Ppa during exercise-Ppa at rest) (r = 0.899, P = 0.0004). These findings suggest that pulmonary artery remodeling leads to reduced recruitability and distensibility of pulmonary vessels and is closely related to exercise pulmonary hypertension.

Aged↗