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Biomedical subjects

Y Tokunaga

Publications and source records attributed to Y Tokunaga.

At least 109 records · Page 6Linked to original sources
PubMed1997

[Surgical management of intractable epilepsy in patients with ganglioglioma].

Long-standing intractable seizures are common manifestation of cerebral gangliogliomas. There is much controversy regarding the most appropriate surgical treatment (lesionectomy vs resection of the epileptogenic cortex with the lesion) for patients with intractable epilepsy associated with gangliogliomas. We reported 2 cases, in which the favorable seizure outcome was obtained following lesionectomy alone. (Case 1) Nine-year-old female developed attack of abnormal sensation in her left upper limb followed by motor seizure in her left limbs since 5 years old. MRI revealed hyperintense tumor in the right medial frontal lobe. Chronic invasive subdural recording showed that ictal onset zone was located in the hand motor area. Following lesionectomy alone, she became free from seizures. (Case 2) Eight-year-old girl had intractable generalized seizure since 6 years old. MRI revealed a cystic tumor in the right parietal lobe. She had multiple spike foci on electroencephalography and magnetoencephalography, and intraoperative electrocorticography failed to reveal the paroxysm. Following lesionectomy, she had good relief with less than one minor seizure per 1-3 months. Thus, lesionectomy, even without resection of the epileptogenic cortex, may improve seizure outcome in patients with ganglioglioma-associated epilepsy.

Brain Neoplasms↗
PubMed1997

[Six patients in whom exacerbation of asthma was complicated by mediastinal emphysema].

We encountered 6 patients with bronchial asthma complicated by mediastinal emphysema. Their average age was 21 years. All were atopic and had histories of asthma in childhood. In 5 of the 6, mediastinal emphysema developed when the patients had upper respiratory infections. In 3, the mediastinal emphysema worsened. After insertion of subcutaneous drains to decrease intramediastinal pressure, the conditions of those 3 patients improved remarkably. The conditions of the other 3 improved after medication only. During the period of this study, 1.24% of all patients treated at Hiroshima Asa Citizen's Hospital for exacerbations of asthma had mediastinal emphysema.

Adolescent↗
PubMed1997

Ultrastructure of the synovial sensory peptidergic fibers is distinctively altered in different phases of adjuvant induced arthritis in rats: ultramorphological characterization combined with morphometric and immunohistochemical study for substance P, calcitonin gene related peptide, and protein gene product 9.5.

OBJECTIVE: To characterize sequential ultramorphological changes in synovial sensory peptidergic fibers in different phases of adjuvant induced arthritis. METHODS: Topographically defined regions of the tarsal joints from arthritic rats were evaluated 7, 10, 14, and 21 days after inoculation with Freund's adjuvant. Peptidergic fibers were identified by high resolution video microscope, then fibers containing calcitonin gene related peptide (CGRP) were visualized by electron microscopy. Morphometric quantification of synovial fibers immunohistochemically stained for CGRP, substance P (SP), and protein gene product 9.5 (PGP 9.5) was done at this time. RESULTS: The control synovial lining contained numerous ramified axon terminals, whereas the sublining contained mostly nerve fiber bundles, except for axon terminals visible around the blood vessels. In arthritis, on Day 14, there were few immunoreactive nerve fibers and terminals. Instead, electron microscopy disclosed numerous activated and/or degenerated axons [CGRP: 2973 +/- 345 vs 495 +/- 288; SP: 657 +/- 344 vs 199 +/- 60; PGP 9.5: 4473 +/- 944 vs 886 +/- 299, all p < 0.05 (units: microm/mm2)]. On Day 21 CGRP and PGP 9.5 immunoreactive fibers were numerous again (4892 +/- 551 and 3613 +/- 1350, respectively), but SP immunoreactive nerve fibers did not seem to regenerate (126 +/- 44). Regenerating nerve fibers had a distinctive ultrastructure and they were always seen in association to Schwann cells. CONCLUSION: The healthy synovial lining is innervated by peptidergic nerve terminals. During the inflammatory phase of arthritis neuropeptides are locally released due to stimulation and degeneration of the axons. The apparently unaffected Schwann cells seem to play a pivotal role in subsequent regeneration of peptidergic axons. However, the ultrastructure and the neuropeptide content (and probably the function) of the regenerating axons are different from those of the normal synovial nerve fibers.

Animals↗
PubMed1996

G protein-gated K+ channel (GIRK1) protein is expressed presynaptically in the paraventricular nucleus of the hypothalamus.

We prepared a specific antibody against GIRK1, the major subunit of the G protein-gated K+ (KG) channel. Immunohistochemical study revealed that GIRK1 immunoreactivity was detected in the presynaptic, but not in the postsynaptic, region in the paraventricular nucleus of the rat hypothalamus (PVN). Therefore, activation of the KG channel may underlie presynaptic inhibition of neurotransmitter release by various agonists, such as dopamine, noradrenaline, opioids, and histamine, in PVN.

Adenosine↗
PubMed1996

FK506 (tacrolimus) and its immunoreactive metabolites in whole blood of liver transplant patients and subjects with mild hepatic dysfunction.

PURPOSE: To determine the concentrations of FK506 and its metabolites in blood from liver transplant patients and subjects with hepatic dysfunction. METHODS: HPLC was combined with an enzyme-linked immunosorbent assay (ELISA) to determine the concentrations of FK506 and its immunoreactive metabolites in human whole blood. RESULTS: In four liver transplant patient, most of the immunoreactivity was seen in the HPLC fractions where unchanged FK506 eluted. FK506 accounted for about 95% or more of the total immunoreactivity in the first days of posttransplant. Immunoreactivity observed in the nonFK506 fractions ranged from 1.6% to 10.7% of the total immunoreactivity; about 30% of the nonFK506 immunoreactivity was due to M-III(15-O-demethyl FK506). Blood from subjects with mild hepatic dysfunction was examined at 1.5 and 6 hours after an oral and intravenous dose, respectively, by HPLC-ELISA. Regardless of the route of administration, more than 96% of the total immunoreactivity was recovered in the FK506 fraction. M-III was detected in the blood of 3 of 6 subjects after an oral dose, but in none of these after an intravenous dose. CONCLUSIONS: ELISA is an appropriate method for therapeutic drug monitoring of FK506.

Adult↗
PubMed1996

Physicochemical characterization of bisphosphonic carboxyfluorescein for osteotropic drug delivery.

Disodium (fluorescein-6-carbonyloxy)acetoaminomethylene bisphosphonate (CF-BP), a prodrug of 6-carboxy-fluorescein, is efficiently absorbed by the skeleton where it hydrolyses to carboxyfluorescein. An osteotropic drug-delivery system based on this bisphosphonic prodrug has been developed as a novel method for site-specific and controlled delivery of drugs to the bone. In this study the physicochemical properties of the prodrug have been characterized by investigating the affinity of CF-BP for hydroxyapatite and the hydrolysis of the compound to carboxyfluorescein. In the binding study, CF-BP bound very rapidly to hydroxyapatite without degradation and carboxyfluorescein was subsequently gradually released by hydrolysis of bound CF-BP. Hydrolysis of CF-BP in buffer solutions followed pseudo-first-order kinetics, and quantitative regeneration of carboxyfluorescein was observed. In addition, regeneration of carboxyfluorescein from CF-BP was accelerated in the presence of fresh rat plasma. These results suggest that CF-BP has the physicochemical properties required for site-specific and controlled delivery of carboxyfluorescein to bones.

Animals↗
PubMed1996

Cytomegalovirus-induced interstitial pneumonitis in a patient with systemic lupus erythematosus.

We report an unusual case of cytomegalovirus (CMV) interstitial pneumonitis (IP) occurring in a 51-year-old Japanese woman with systemic lupus erythematosus (SLE). She developed hypoxemia after intensive immunosuppressive therapy with prednisolone and cyclophosphamide. Fine crackles were audible in the lower lungs bilaterally. Chest X-ray and computed tomography confirmed the presence of IP. CMV-antigenemia was confirmed by immunological staining of leukocytes using the peroxidase-labeled monoclonal antibody, HRP-C7. Hypoxemia improved gradually on methylprednisolone pulse therapy and gancyclovir, and CMV-antigen positive leukocytes disappeared from the peripheral blood. Data suggest the importance of CMV as a cause of IP in SLE, and the usefulness of the assay for CMV-antigenemia with C7-HRP for rapid diagnosis.

Antigens, Viral↗
PubMed1996

Osteotropic drug delivery system (ODDS) based on bisphosphonic prodrug. III: Pharmacokinetics and targeting characteristics of osteotropic carboxyfluorescein.

An osteotropic drug delivery system (ODDS) based on a bisphosphonic prodrug has been developed as a novel method for site-specific and controlled delivery of drugs to the bone. The pharmacokinetics and the targeting efficiency of a bisphosphonic prodrug of carboxyfluorescein (CF), disodium (fluorescein-6-carbonyloxy) acetoaminomethylene bisphosphonate (CF-BP), was investigated in rats. After intravenous injection, CF-BP was rapidly taken up into the skeleton, and subsequently cleared from the bone by hydrolysis of its ester linkage at a half-life of 3.2 days. On the other hand, the bone concentration of regenerated CF gradually increased to reach the maximum at 14 days and slowly decreased up to 56 days. Kinetical analysis revealed that bone tissue acts as a reservoir of regenerated CF to supply the parent compound into the systemic circulation. In contrast with CF-BP, CF injected intravenously showed rapid clearance from the plasma and extremely low bone distribution. Therapeutic availability (TA) and drug targeting index (DTI), which were calculated on the basis of the AUCs for CF in the bone and plasma after injection of CF-BP and CF, were 1551 and 6689, respectively. These results suggest that ODDS has a potential to improve not only apparent potency but also therapeutic index of the drugs which exhibit their pharmacological effects in the bone.

Animals↗
PubMed1996

[Systemic vascular change associated with moyamoya-like cerebrovascular disease and microvascular coronary artery disease].

A 34-year-old man with hypertension and diabetes mellitus developed dizziness and visited our institute. He had history of headache with numbness of the right hand since age 15 years and left occipital lobe infarction at age 28 years. The cerebral angiogram showed several changes peculiar to advanced stage of moyamoya disease (spontaneous occlusion of the circle of Willis), i.e. segmental stenoses or occlusions of bilateral internal carotid arteries, left vertebral artery and left posterior cerebral artery with abnormal vascular networks at the bilateral basal ganglia. He was also diagnosed to have asymptomatic ischemic heart disease. The coronary angiogram showed diffuse sclerotic lesions of left anterior descending and right coronary arteries without significant stenosis, which suggested the presence of microvascular lesion as a cause of myocardial ischemia. Coronary disease has been rarely reported as a complication of moyamoya disease, and microvascular coronary artery disease has never been described. Moyamoya disease should be regarded as a part of systemic vascular disorders, and the evaluation of extracerebral cardiovascular system is necessary to clarify pathophysiology of this disease.

Adult↗
PubMed1995

Osteotropic drug delivery system (ODDS) based on bisphosphonic prodrug. I: synthesis and in vivo characterization of osteotropic carboxyfluorescein.

An osteotropic drug delivery system (ODDS) based on a bisphosphonic prodrug was designed as a novel method for site-specific and controlled delivery of drugs to the bone. Due to the chemical adsorption of bisphosphonic promoiety to the mineral component, hydroxyapatite, a bisphosphonic prodrug is predominantly taken up into the bone. To verify the concept, bisphosphonic promoiety was chemically introduced into 6-carboxyfluorescein (CF) as a model compound and the disposition after intravenous injection was studied in rats. The bisphosphonic prodrug of CF, disodium (fluorescein-6-carbonyloxy) acetoaminomethylene bisphosphonate (CF-BP) was highly taken up to the skeleton (62.1% of dose) and the remainder was excreted into the urine (35.9% of dose). Subsequently, regeneration of CF by hydrolysis of CF-BP in the bone was observed. The microscopic observation showed that CF-BP was buried into the bone with a calcification of the bone. According to the remodeling of the bone, bisphosphonic prodrug buried was supposed to be released in the vicinity of the osteoclast or resorption surface of the bone. Thus, it is suggested that ODDS has a potential to achieve osteoclast-specific or resorption surface-specific targeting of the drugs.

Animals↗
PubMed1994

Primary central nervous system lymphomas. Immunophenotypic, virologic, and cytogenetic findings of three patients without immune defects.

BACKGROUND: Primary central nervous system (PCNS) lymphoma is a relatively rare disease, but an increasing incidence is reported. The Epstein-Barr virus (EBV), which is often found in lymphomas of immunocompromised patients, has been implicated in the development of lymphomas. Many cytogenetic analyses of nodal B cell lymphomas have been performed, but few studies on PCNS lymphomas have been reported. METHODS: The detection of EBV genome using the polymerase chain reaction (PCR) method and cytogenetic studies were performed, in addition to histopathologic and immunophenotypic approaches in biopsied tissue from three patients with PCNS lymphoma. Immunosuppressive states and exposure to mutagens were not clear in all patients. RESULTS: Histopathologic examination disclosed a diffuse type of malignant lymphoma in all patients. Immunophenotypic studies revealed B cell phenotype in all patients, two of whom showed positive reaction for CD5. The PCR method revealed no involvement of EBV genome in tumors in any patients. The cytogenetic study showed clonal chromosome abnormalities in all patients, and abnormalities of chromosome 1 (1q21), 6 (-6, 6q15 and 6q21), 7 (-7 and 7p15), and 14 (14q24 and 14q32) were prominent. The t(6;14)(q15;q32) observed in Patient 1 is the first case to be reported in human de novo lymphoma. CONCLUSIONS: These findings indicate that the causative role of EBV in PCNS lymphoma without immune defects is not clear. The cytogenetic findings were similar to those observed in nodal B-cell lymphoma, suggesting that the origin of PCNS lymphoma cells does not differ from nodal B cell lymphoma cells cytogenetically.

Aged↗
PubMed1994

Presacral epidermal cyst found in an adult male with a high CEA content: report of an unusual case.

A 63-year-old Japanese man presented with constipation, having noticed flat stools for several years. Digital examination of the rectum, followed by barium enema, colono-fiberscopy, computed tomography (CT), and magnetic resonance imaging (MRI) revealed an oval mass located between the retrorectal and presacral space without any mucosal lesion. This mass had narrowed the rectal lumen by compressing the rectum anteriorly. Although the plasma levels of the tumor markers were within the normal range, those of the tumor contents were elevated with a carcinoembryonic antigen (CEA) of 118 ng/mL, while the alpha-fetoprotein (AFP) value was 1 ng/mL. The tumor was completely extirpated through an abdominal incision, and there has been no evidence of recurrence thus far. Histological examination showed that the tumor wall was made of keratinized stratified squamous epithelium without any cutaneous adnexal structure, and hence it was diagnosed as an epidermal cyst. CEA was identified in these benign epithelial cells by immunoperoxidase staining using a monoclonal antibody. To the best of our knowledge, there have been only four other cases with a presacral epidermal cyst documented in the Japanese literature, all of whom were female. Our patient is the first reported case of an adult male with a presacral epidermal cyst.

Carcinoembryonic Antigen↗
PubMed1994

Living related liver transplantation in children.

We reviewed 37 living related liver transplantations (LRLT) performed by our department during the last 27 months on children with end-stage liver disease. The patients were 15 boys and 22 girls aged 7 months to 15 years with biliary atresia (27), cryptogenic cirrhosis (3), Budd-Chiari syndrome (2), progressive intrahepatic cholestasis (2), protoporphyria (1), Wilson's disease (1), and fulminant hepatitis (1). The donors were 14 fathers and 23 mothers. Grafts were made from the left lateral segment (19), left lateral segment with partial S4 (11), left lobe (6), and right lobe (1). After graft harvesting all donors resumed normal liver function and normal life. The recipient underwent total hepatectomy with preservation of the inferior vena cava. FK506 and low-dose steroids were used for immunosuppression. The survival rate was 90% (27/30) in elective cases and 57% (4/7) in emergency cases. Six recipients had functioning grafts but died of extrahepatic complications. Hepatic vein stenosis occurred in 3 cases at 3 months after LRLT and was successfully treated by balloon dilatation. Portal vein stenosis occurred in 1 case at 8 months after LRLT and was also safely dilated. We incurred no hepatic artery thrombosis after introducing microsurgery techniques. Among 12 viral, 5 bacterial, and 3 fungal postoperative infections, 1 Candida pneumonia and 1 EBV-associated lymphoma were lethal. Three patients with ABO-blood group compatible grafts and one with an incompatible graft developed acute rejection, which was controlled in evey case by steroid bolus and/or increasing the dose of FK506. There were no definite episodes of rejection in ABO-identical cases. Children with moderate growth retardation (> or = -1.5 SD of normal growth) caught up in growth soon after LRLT, but those with severe retardation (<-1.5 SD) were slow to attain age-normal height. Appropriate timing, meticulous surgical procedures, and comprehensive management of complications are crucial for successful outcome with LRLT. LRLT is a promising option for alleviating the shortage of livers for pediatric transplantation and may be regarded as an independent modality to supplement cadaver donation.

Acute Disease↗
PubMed1994

Long-term use of FK 506 in living related liver transplantation.

FK 506 (Tacrolimus) was used with steroids to treat 61 pediatric patients who received living related partial liver transplantation. Fifty-two recipients survived and 9 died between 6 months and 3 years after transplantation. In the surviving patients, oral doses of Tacrolimus were tapered from 0.298 +/- 0.277 mg/kg daily at 1 month after transplantation to 0.078 +/- 0.054 at 24 months after transplantation. The 12 h trough levels of Tacrolimus were 12.6 +/- 7.1 ng/ml and 4.1 +/- 2.4 at 1 and 24 months after transplantation, respectively. The percentage of recipients free from steroids was 77%, 97%, and 94% at 6, 12, and 24 months after transplantation, respectively. Liver allograft rejection was encountered in seven recipients, five of whom were treated by steroid pulse therapy and a dose increase of Tacrolimus; the remaining two required OKT3. However, there was no episode of rejection that required retransplantation. Infectious complications encountered in 34 patients included 12 bacterial, 3 fungal, and 19 viral infections. Two recipients died one of fungal pneumonia and one of Epstein-Barr virus-associated lymphoproliferative disorder. Regarding adverse reactions of Tacrolimus, hypertension was observed in 28 patients, diabetes mellitus in 3, pancreatitis in 3, convulsion in 1, tremor in 12, itching in 5, and pigmentation in the oral mucosa in 2. Slightly increased values of creatinine were observed in most of the patients; however, an abnormal increase of serum of serum creatinine (> 1.0 mg/dl) was confined to the complicated cases. Improvement of somatic growth was observed in 21 patients (62%) and 13 (75%) at 12 and 24 months after transplantation, respectively. The long-term use of Tacrolimus is highly effective in terms of its immunosuppressive potential and reduced adverse reaction. Steady growth development can be expected in pediatric recipients free from steroids.

Adolescent↗
PubMed1994

Living-related liver transplantation for fulminant hepatic failure in children.

Liver transplantation is increasingly accepted as a choice of treatment for fulminant hepatic failure (FHF) since it has been proved to significantly improve the survival rate in these patients compared with other therapeutic modalities. We have successfully performed a total of 76 living related liver transplantations (LRLT) three of which were for FHF. The first case was an 11-year-old boy with FHF due to an unidentified cause. He had required plasmapheresis a total of 24 times and haemofiltration to save his life before LRLT. He was transplanted with a left lobe (420 g) graft, calculated as 1.05% of his weight (40 kg). He recovered hepatic function uneventfully and was discharged from hospital after 7 weeks. The second case was a 13-year-old girl who developed FHF with grade III encephalopathy due to acute Wilson's disease, and was referred to us. She underwent LRLT with a left lobe graft (440 g), estimated as 0.95% of her weight (47 kg), which functioned well after surgery. The third case was a 13-year-old girl with grade II encephalopathy due to acute Wilson's disease. She was 27% obese with a body weight of 58 kg. She underwent LRLT with ABO blood group incompatibility with a left lobe (352 g), estimated as 0.80% of her weight (modified 44 kg). She was discharged with sensorimotor neuropathy due to vitamin B deficiency. The present results suggest that LRLT is feasible for FHF both clinically and ethically, and that a partial liver graft weighing around 1% of the recipient's weight can maintain the recipient's life. We limit the diagnostic indication for LRLT to chronic liver disease, since an urgent situation may affect a voluntary decision for the patient's parents to donate the partial liver. However, LRLT is thought to be an acceptable choice of treatment provided it is requested by the patient and family. Furthermore, it is a potential option for resolving the graft shortage in paediatric liver transplantation, being independent of cadaver donor availability.

Adolescent↗