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Biomedical subjects

H Kikuchi

Publications and source records attributed to H Kikuchi.

At least 253 records · Page 14Linked to original sources
PubMed1997

Features of DNA oligonucleosomal fragmentation in human tumor cell lines and its detection by flow cytometry: utility and limitations.

Cultured HL-60, HeLa S3 and WiDr cells were treated with various doses of ethanol, then subjected to flow cytometry and gel electrophoresis of cellular DNA. On electrophoresis of DNA from HL-60 cells treated with 0.5 or 1.0 mM ethanol, a ladder pattern was recognized after 3 h. At higher doses of ethanol (2.0 and 5.0 mM), a smear pattern resulted. On flow cytometry, however, A0 cells (lower fluorescence level than G0+G1 cells) were noted from 0.5 to 5.0 mM ethanol. The observation of A0 cells at higher doses indicated loss of DNA after random DNA degradation. HeLa S3 and WiDr cells were partially detached from flasks after administration of ethanol and separated into adherent and non-adherent categories. In DNA from non-adherent HeLa S3 cells treated with 0.5 mM ethanol, a ladder pattern was observed after 24 h. On flow cytometry, prior to the appearance of A0 cells, an accumulation in the G2 + M-phase became obvious after 3 h. Increased mitotic indices indicated that this phenomenon was due to M-phase arrest. Adherent HeLa S3 cells showed no DNA oligonucleosomal fragmentation or A0 cells. These findings indicate that detection of A0 cells by flow cytometry is not proof of cell death by DNA oligonucleosomal fragmentation.

Apoptosis↗
PubMed1997

"Cavernous sinus EEG": a new method for the preoperative evaluation of temporal lobe epilepsy.

PURPOSE: In presurgical evaluation of temporal lobe epilepsy (TLE), invasive methods are necessary if results of various noninvasive methods are not sufficiently convergent enough to identify the epileptogenic area accurately. To detect the epileptiform discharges originating specifically from the mesial temporal lobe, we applied the cavernous sinus catheterization technique. METHODS: We placed Seeker Lite-10 guide wire electrodes into bilateral cavernous sinus through the internal jugular veins to record EEG (cavernous sinus EEG) in 6 patients with intractable TLE. Scalp EEG was simultaneously recorded in all 6 and electrocorticogram (ECoG) was also recorded in 4. RESULTS: The cavernous sinus EEG demonstrated clear epileptiform discharges, sometimes even when they were absent on the simultaneously recorded scalp EEG. The epileptiform discharges recorded from the cavernous sinus electrodes were specifically associated with those in the mesial temporal region on ECoG. Ictal EEG pattern originating from mesial temporal lobe was also clearly documented on the cavernous sinus EEG. CONCLUSIONS: This new, semi-invasive method of identifying epileptogenic areas can detect the epileptiform discharges specifically arising from the mesial temporal lobe; it is as useful as or complements the invasive techniques such as foramen ovale or depth recording.

Adolescent↗
PubMed1997

[A pathological study of cytomegalovirus infections in autopsied cases with adult T-cell leukemia].

In this study, cytomegalovirus (CMV) infection was found in eleven of 21 autopsied cases (52.4%) with adult T-cell leukemia (ATL). Seven cases (63.6%) revealed disseminated infection in more than three organs. The lungs were involved in all eleven cases (100%), adrenal glands in eight cases (72.7%), esophagus in four cases (36.4%), and stomach, small intestine and urinary bladder in three cases (27.3%). Histopathological findings suggested that lung involvement was the cause of death in five of the 11 cases, the small intestine were involved in two of the 3 cases, and the adrenal glands were involved in one of the 8 cases. In summary, CMV infection was found to be the main cause of death in five (45.5%) of the 11 ATL patients.

Adrenal Glands↗
PubMed1997

[Immunodeficiency and carcinogenesis in patients with chronic active Epstein-Barr virus infection].

Three adult patients with chronic active Epstein-Barr virus infection (CAEBV) had high anti-EBV-VCA antibody, positive anti-EA, low anti-EBNA and were associated with systemic lymphadenopathies and immunosuppression. The case 1 and 2 had elevated serum immunoglobulin levels, and recurrent infections, and case 3 showed pancytopenia. These 3 cases developed both EBV and latent membrane protein (LMP) positive malignant histiocytosis, EBV positive but LMP negative plasmacytoma, and EBV negative acute myelogeneous leukemia, respectively. It was suggested that CAEBV belonged to high risk groups for the development of malignant neoplasms. Since HLA of the case 1 and his father was identical, we conducted a in vitro cytotoxicity test using EBV transformed autologous B lymphocytes, K562 cells, and Raji cells to clarify the association of immunosuppression and HLA. The case 1 showed a low level of specific cytotoxicity to autologous EBV transformed B cells, while his parents were negative for the specific cytotoxicity. The patient and his parents developed inducible cytotoxicity to all targets after in vitro incubation of peripheral mononuclear cells with recombinant interleukin 2 (rIL-2) for 7 days. The patient and his mother showed lower enhancement of cytotoxicity, while HLA identical father could induce good cytotoxic activity to all targets as well as normal controls, indicating that a low IL-2 induced cytotoxic activity observed in CAEBV was independent of HLA associated immunoregulation at least in the case 1. Further studies are required to clarify the exact mechanisms responsible for the development of CAEBV.

Adult↗
PubMed1997

Cerebral aneurysms arising at nonbranching sites. An experimental Study.

BACKGROUND AND PURPOSE: The origin and pathogenesis of cerebral aneurysms arising at nonbranching sites are not clear. Using our animal model to induce cerebral aneurysms in rats, we examined induced aneurysms that developed at nonbranching sites. METHODS: In 35 Sprague-Dawley rats, the left common carotid artery was ligated and renal hypertension was produced to induce cerebral aneurysms. Twelve months later, the circle of Willis was carefully examined under a dissecting microscope. RESULTS: Other than cerebral aneurysms at branching sites of the circle of Willis, aneurysmal bulges developing at nonbranching sites were found in the proximal portion of the posteriorice rebral artery (P1) on the side of carotid ligation, which supposedly acted as a major collateral pathway after the ligation, in 19 of 35 treated rats. A total of 30 lesions were found in these 19 rats, and they were classified into fusiform aneurysms (22 lesions) involving the entire vessel wall for a short distance and saccular aneurysms (8 lesions) involving only a part of the wall and expanding laterally from the vessel wall. These P1s became larger in caliber and more tortuous after ligation. Aneurysms developed more frequently in proportion to these changes in these vessels. Moreover, most aneurysms in these vessels developed at or near the curvatures. All of the lateral aneurysms were found on the lateral wall of the curvatures of the vessels. CONCLUSIONS: The present findings indicate that cerebral aneurysms at nonbranching sites and saccular aneurysms at branching sites can occur under the same etiologic conditions. The site of origin is strongly related to hemodynamic stress.

Animals↗
PubMed1997

Favorable effect of hemodialysis on decreased serum antioxidant activity in hemodialysis patients demonstrated by electron spin resonance.

There is considerable evidence that uremic patients are in a highly peroxidative state. The purpose of this study was to investigate the serum antioxidant activity that may regulate, or represent, the redox state in vivo. Serum from pre- and posthemodialysis patients and from healthy control subjects was added to a system generating the hydroxyl radical, and then the signal intensities of reactive oxygen species were measured by electron spin resonance and spin-trapping technique. The electron spin resonance signals of the reaction mixture containing prehemodialysis sera were significantly stronger than those of the reaction mixture containing healthy sera (P < 0.001, n = 19), and there was no significant difference in the signals between the reaction mixture containing posthemodialysis and healthy sera. These findings demonstrated that serum antioxidant activity in hemodialysis patients is significantly decreased, and this pathological condition is improved by hemodialysis treatment.

Adult↗
PubMed1997

Neurotoxicity testing of a new bioactive bone cement.

Bioactive bone cement (BABC) is a novel artificial bone cement. It has some noteworthy characteristics that are applicable to neurological surgery. The toxicity of BABC to the nervous system was tested by implanting BABC and polymethylmethacrylate (PMMA) cement as a control at the parietal and the suboccipital regions of the skull in beagles. The auditory brainstem response (ABR) was tested before and after implantation. Sections of the cerebral cortex and the acoustic nerve were examined at 3 and 6 months after implantation. No abnormal ABR was found in any animals. Histological examination of the cerebral cortex and acoustic nerve demonstrated slight gliosis in both the BABC and PMMA cement groups, but no other abnormalities.

Animals↗
PubMed1997

Endovascular treatment of a partially thrombosed giant basilar tip aneurysm using interlocking detachable coils--case report.

A 65-year-old female presented with visual acuity loss. Magnetic resonance imaging confirmed the presence of a partially thrombosed giant aneurysm on the basilar tip. Cerebral angiography showed the opacified lumen of the aneurysm was 25 x 15 mm with a broad-based neck. Using a transfemoral approach, a microcatheter was guided through the vertebral artery and placed directly into the aneurysm under local anesthesia. Interlocking detachable coils were deposited into the patent portion of the aneurysm, resulting in 95% obliteration of the aneurysm and preservation of the parent artery. No complication was observed during or after surgery. Follow-up angiography 2 months later demonstrated the aneurysm was 95% occluded. No coil compaction was observed. Endovascular coil embolization therapy provides a therapeutic option for management of basilar tip aneurysms.

Aged↗
PubMed1997

Potential efficacy of basic fibroblast growth factor incorporated in biodegradable hydrogels for skull bone regeneration.

Biodegradable gelatin hydrogels incorporating basic fibroblast growth factor (bFGF) were evaluated for their efficacy in bone regeneration using a rabbit model. Hydrogels with water contents of 85% and 98% were prepared using chemical crosslinking of gelatin with an isoelectric point of 4.9 in aqueous solution and, after freeze drying, were impregnated with an aqueous solution of bFGF to obtain bFGF-incorporated gelatin hydrogels. When they were implanted into bone defects measuring 6 mm in diameter in rabbit skulls (six animals/group), complete closure of the defect was observed at 12 weeks after implantation, regardless of the water content of the hydrogels. In contrast, bFGF did not enhance bone regeneration when applied to the skull defect in solution with phosphate-buffered saline (PBS). Also, gelatin hydrogels lacking bFGF were not effective in inducing bone formation, with fibrous tissue growing into the defect instead, similar to the skull defect seen in control rabbits treated with PBS. This indicates that the presence of hydrogels did not interfere with bone regeneration at the skull defect, probably because of their disappearance during biodegradation. It is concluded that the gelatin hydrogel is a promising matrix for effective induction of biological activity of bFGF for bone regeneration in skull and sinus defects.

Animals↗
PubMed1997

Development of a dural substitute from synthetic bioabsorbable polymers.

A new bioabsorbable composite sheet was developed to provide a substitute for the dura mater and was evaluated histologically and biomechanically using rats and rabbits. This composite, composed of two L-lactic acid-epsilon-caprolactone (50% L-lactic acid, 50% epsilon-caprolactone) copolymer films and a poly(glycolic acid) nonwoven fabric, displayed good mechanical properties and was completely absorbed 24 weeks after implantation in the back of rats. Histological evaluation of the composite sheet was undertaken by implanting it in 31 rabbits with dural defects and examining the sites of implantation 2 weeks to 26 months later. No infection, cerebrospinal fluid leakage, evidence of convulsive disorders, significant adhesion to underlying cortex, or calcification was noticed in any cases. In addition, the regenerated duralike tissue had a high pressure-resistant strength 2 weeks after implantation. The authors conclude that this new bioabsorbable composite sheet can be successfully used as a dural substitute.

Absorption↗
PubMed1997

[Functional changes in the cochlea of guinea pigs in chronic renal failure--electrocochleography. Effect of noise exposure].

An animal model of chronic renal failure (CRF) was created by the 5/6 nephrectomy procedure in guinea pigs. Levels of serum Cr and BUN were abnormally elevated at 1,2 and 3 months after the procedure. ECoG (CAP, CM) was recorded through a silver ball electrode placed on the round window 1,2 and 3 months after surgery. EP was measured with a glass microelectrode from the scala media via the round window membrane. Only slight ECoG changes were seen 1 month after surgery. On the other hand, moderate or profound changes were observed 2 and 3 months after-surgery. No significant decrease in EP was found in the post-surgery animals which distinctly showed abnormal CAP, CM, although a limited number of animals were studied. The above results indicate that CRF is one of the etiological factors of cochlear dysfunction and the sensory hair cells appeared to be the site of the lesion. To study the interaction between noise exposure and CRF, 1 month post-surgery animals with only a little change in ECoG were exposed to a broad band noise. Changes in the ECoGs were followed up for 6 hours after the noise exposure. In contrast to the controls, animals with CRF did not recover from the reduced ECoG which occurred immediately after the noise exposure. This suggests synergistic interaction between noise and CRF.

Animals↗
PubMed1997

[The serum zinc level in patients with tinnitus and the effect of zinc treatment].

We measured the serum zinc level in patients with tinnitus and evaluated the effectiveness of zinc in the treatment of tinnitus. Blood zinc levels were measured in 121 patients with tinnitus. All patients were examined between 1995 and 1997 at the outpatient clinic of otorhinolaryngology St. Marianna University Toyoko Hospital. Forty-seven patients who had received any drug such as a calcium channel blocker and others or had been affected by any diseases were excluded and therefore 74 patients consisting of 46 females (62%) and 28 males (38%) were investigated. Twenty two healthy volunteers served as a control group. The mean age and standard deviations for the tinnitus group and the control group were 47.8 +/- 17.1 and 31.4 +/- 8.2 years, respectively. There was a significant decrease (p < 0.0001) in serum zinc levels in patients with tinnitus compared with the control group. Because there was a significant difference (p < 0.0001) in age distribution between tinnitus and control groups, patients were selected by their age in order to neglect the effect of aging. In this situation, a significant difference (p < 0.01) was noted between the tinnitus group and control group. Low blood zinc level was defined by using the mean and standard deviation for the control group (mean-1 S.D.). We treated patients with low blood zinc levels. A total dose of 34-68 mg of Zn++ was administered daily for over 2 weeks. The degree of tinnitus was expressed on a numeric scale from 0 to 10 before and after treatment. Blood zinc levels were significantly elevated (p < 0.05) after treatment. We found a significant decrease (p < 0.01) in the numeric scale. These findings suggest that zinc is useful in at least some patients suffering from tinnitus. It is possible to classify patients with tinnitus by measuring serum zinc level and this leads to improvement of the overall treatment effect.

Adolescent↗
PubMed1997

[Serum selenium contents in cancer patients].

The conclusions were confirmed by determining the serum Selenium levels in 2099 cancerous of non-cancerous patients as follows: 1) The mean serum Selenium levels of males is significantly higher than in females. 2) Serum Selenium levels tend to decrease with age. 3) The serum Selenium levels of cancerous patients is significantly lower than in non-cancerous patients. 4) No significant difference in the serum Selenium levels was observed between cancerous patients with and without metastasis. Most patients without metastasis are free from cancer after surgery, so the low serum Selenium level in cancerous patients may not be induced by the tumor but was present before the tumor.

Adult↗
PubMed1997

[A malignant rhabdoid tumor appearing simultaneously in the kidney and the brain of an infant: case report].

A 6-month-old female was admitted to the hospital with bad temper and decreased sucking power. CT scans revealed tumors in her right kidney and left cerebellum. The patient underwent right radical nephrectomy to excise the kidney tumor. The pathological diagnosis was malignant rhabdoid tumor (MRT). Seven days later, the patient underwent left suboccipital craniectomy for total excision of the cerebellar tumor. The cerebellar tumor existed extraaxially, and consisted of a solid mass lesion and a cystic lesion. Histological examination revealed that it was also a malignant rhabdoid tumor. A follow-up CT, 1.5 months after surgery, revealed a recurrence of the kidney tumor and metastasis to the chest wall and lung. The patient received 16.9 Gy radiotherapy to the abdominal tumor and chemotherapy with etoposide, carboplatin, and ifosfamide. However, she died of respiratory insufficiency 4 months after surgery, though neither recurrence nor metastasis was found in the brain. Nor was there evidence of leptomeningeal dissemination. MRT is a highly malignant tumor that occurs most frequently in the kidney. However, it can also occur in other tissues, including the brain. This tumor occurs most commonly in children under 2 years of age. There is a 3:2 male predominance. The median length of overall survival of MRT in the brain is 6 months. MRT contains nests or sheets of rhabdoid cells. A typical rhabdoid cell has an eccentric round nucleus with a prominent nucleolus and a plump cell body. MRT is composed entirely or partly of rhabdoid cells. Many MRTs have other components, such as PNET areas, mesenchymal area, and epithelial areas. For this reason, they are sometimes called atypical teratoid/rhabdoid tumors. MRTs in the brain contain fewer rhabdoid cell areas than MRT in the kidney. This makes diagnosing MRT in the brain more difficult. A careful search of the entire specimen for variations in pattern and cell type, along with application of immunohistochemical methods is the most useful method of obtaining a diagnosis. In our case, the cerebellar tumor consisted of rhabdoid cell areas, mesenchymal areas, and PNET areas. The cerebellar tumor contained fewer rhabdoid cell areas than the kidney tumor. However, the rhabdoid cell areas in the cerebellar tumor were almost the same as those in the kidney tumor. Furthermore, immunohistochemical staining was positive for vimentin and keratin in the rhabdoid cell areas. Therefore, we were able to make a diagnosis of MRT. It is possible that some of the previously reported cases diagnosed as CNS PNET were actually MRT in the brain, especially if the cases were associated with MRT in the kidney.

Cerebellar Neoplasms↗
PubMed1997

[A case of cavernous dural arteriovenous fistula resulting in intracerebral extravasation during transvenous embolization].

Cortical venous drainage has been described as one of the major risk factors for dural arteriovenous fistula, which may induce venous hypertension leading to venous ischemia or intracerebral hemorrhage. However, it is rather rare to observe cortical venous drainage manifesting in this way in the cavernous sinus region. We report a case of a 55-year-old gentleman with a right cavernous dural arteriovenous fistula, presenting with conjunctival chemosis, exophthalmus and ocular hypertension on the affected side. Magnetic resonance imaging showed a small intracerebral hemorrhage in the right frontal lobe. Cerebral angiography revealed a dural arteriovenous fistula in the right cavernous sinus draining into the right olfactory vein via the uncal vein, as well as into the superior and inferior ophthalmic veins. This unusual cortical venous reflux was thought to be consistent with the intracerebral hemorrhage found on the magnetic resonance imaging. The patient underwent transvenous embolization for the dural arteriovenous fistula using an inferior petrosal catheterization into the uncal vein was difficult, and the cortical venous reflux through the vein seemed to be slight. However, extravasation of the contrast material occurred in the right frontal lobe after obliteration of the ophthalmic veins during the procedure. The cause of the extravasation was suspected to be the same olfactory vein that had been involved in the previous intracerebral hemorrhage. The obliteration of the dural fistula was continued rapidly, and the fistula disappeared after the embolization. Neurologically, the patient had no noticeable troubles, except for a mild headache. The pretreatment symptoms were alleviated within several days, and the patient was discharged in a week. We emphasize the following points from this rare case in order to facilitate a safer procedure during transvenous embolization for cavernous dural arteriovenous fistula. It is important to obliterate the cortical venous drainage as early as possible, even if the reflux is small or the catheterization is difficult. Repeated, careful sinography is useful for the evaluation of the drainage pattern at certain stages during the transvenous embolization procedure.

Arteriovenous Fistula↗
PubMed1997

[Diffuse alveolar hemorrhage associated with idiopathic interstitial pneumonia syndrome after allogeneic bone marrow transplantation].

A 24-year-old male with myelodysplastic syndrome (refractory anemia) was treated with allogeneic bone marrow transplantation (BMT) from HLA-identical brother on September 9, 1994, after conditioning with busulfan and cyclophosphamide. From early in April 1995, the patient complained of cough and fever. Chest X-ray showed interstitial infiltrates involving hilar and lower lung fields. Although pulmonary infiltrates were resolved with methylprednisolone pulse therapy, on May 19, the patient rapidly deteriorated with dyspnea. Diffuse alveolar infiltrates appeared on chest X-ray and he died of respiratory failure. At autopsy, diffuse alveolar hemorrhage accompanied with thickening of the alveolar walls and interstitial infiltration of lymphocytes was demonstrated. There was no evidence of bleeding in other organs. This is a rare case of diffuse alveolar hemorrhage in the late stage of allogeneic BMT. This report should lead to an evaluation of this disease by the collection of similar cases.

Adult↗