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Biomedical subjects

T Aoki

Publications and source records attributed to T Aoki.

At least 271 records · Page 15Linked to original sources
PubMed1999

Molecular analysis of complement component C8beta and C9 cDNAs of Japanese flounder, Paralichthys olivaceus.

The amino acid sequences of the human terminal complement components show extensive structural similarity to each other. In this study the C8beta and C9 cDNAs of Japanese flounder, Paralichthys olivaceus, were cloned and analyzed. The derived deduced amino acid sequences of the two terminal components were homologous to those of humans, in that the sequences of both species contained LDL receptor, EGF precursor, and two thrombospondin domains. Japanese flounder C9 was found to have a second thrombospondin region in the C-terminus, similar to that reported for rainbow trout and pufferfish. Moreover, these two complement component cDNAs of Japanese flounder had partial similarity to human perforin. These findings show that Japanese flounder C8beta and C9 have similar structures, which supports the hypothesis that the terminal complement genes originated from the same ancestral gene. Collectively, these features emphasize the strong similarity among the members of the terminal complement family.

Amino Acid Sequence↗
PubMed1999

The radiological findings in chronic expanding hematoma.

OBJECTIVE: To identify the characteristic MRI findings of chronic expanding hematoma correlated with the pathology. DESIGN AND PATIENTS: Three patients who had a chronic expanding hematoma involving the musculoskeletal system were reviewed retrospectively. RESULTS AND CONCLUSION: Huge soft tissue masses suggestive of malignancy with destruction of the bony structure were revealed on radiography and computed tomography. MRI showed the masses to exhibit heterogeneous signal intensity on both T1 and T2-weighted images with a peripheral rim of low signal intensity, reflecting the central zones of fluid collection due to fresh and altered blood with a wall of collagenous fibrous tissue. These MRI findings were seen in all three patients and are considered to be characteristic; they assist in differentiation from neoplasm in consideration of the history of trauma or surgery.

Aged↗
PubMed1999

Intracranial hemorrhage in an infant owing to vitamin K deficiency despite prophylaxis.

A 3-month-old male infant with intracranial hemorrhage attributable to a vitamin K deficiency is reported. Vitamin K2 was administered orally at birth and then at 5 days and I month of age. Oral antibiotics were also given 2 days before the onset of bleeding. Although the incidence of intracranial hemorrhage resulting from vitamin K deficiency has decreased since the introduction of vitamin K2 prophylaxis, spontaneous intracranial hemorrhages are still being reported in infants. We suggest that vitamin K prophylaxis is needed especially for breast-fed infants and for those undergoing antibiotic therapy.

Cerebral Hemorrhage↗
PubMed1999

Immediate increase of portal pressure, reflecting sinusoidal shear stress, induced liver regeneration after partial hepatectomy.

The mechanisms whereby hepatocytes in the normal liver can be primed for replication following partial hepatectomy (PHx) are poorly understood. To determine whether "shear stress," which is induced by acute portal hypertension after PHx, is involved in liver regeneration, we studied liver regeneration in rats with splenic transposition (SPT) in which we can minimize the postoperative elevation of portal pressure. Rats underwent 70% PHx following splenic transposition or sham surgery and were killed at various time points to measure portal pressure and other factors. In the control groups, the portal pressure was significantly increased immediately after surgery, peaking at 48 h, and returning to near the preoperative levels by 168 h after PHx. In the SPT group, although portal pressure increased immediately, it decreased to the control levels 6 h after PHx and thereafter repeatedly increased. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels peaked at 24 and 6 h after PHx, respectively. Proliferative cell analysis was done using MIB-5 antibody, and there were no significant differences between the two groups. Furthermore, liver weight was restored in the same way in both groups. Taken together, the results suggest that an immediate increase in portal pressure is necessary for the initiation of liver regeneration.

Animals↗
PubMed1999

Tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) stimulate osteoclastic bone resorption.

As both tissue inhibitor of metalloproteinases-1 (TIMP-1) and TIMP-2 have been reported to inhibit bone resorption, we examined whether TIMP-1 or TIMP-2 in fetal calf serum (FCS), with which culture media were supplemented, affected osteoclastic bone resorption in vitro. Contrary to our expectation, almost complete suppression of osteoclastic bone resorption was observed when both TIMP-1 and TIMP-2 were removed from the FCS. Bone resorption was, however, almost fully restored by the addition of recombinant TIMPs. TIMPs stimulate bone resorption at significantly lower concentrations (approximately ng/ml) than those (approximately micrograms/ml) required to inhibit bone resorption. To understand the mechanism of TIMP-dependent bone resorption, we counted and compared the number of tartrate-resistant acid phosphatase-(TRAP-) positive and multinuclear cells in cultures containing either 10% FCS or TIMP-1-free and/or TIMP-2-free FCS. There was essentially no difference in number among these, suggesting that the TIMP role seems to be related to the functional expression of osteoclasts. Metalloproteinase inhibitors, either BE16627B[L-N-(N-hydroxy-2-isobutylsuccinynamoyl)-seryl-L-val ine] or R94138 ¿N-methyl-(3S)-2-[(2R)-2-hydroxycarbamoylmethylundecanoyl] hexahydropyridazine-3-carboxamide¿, could not replace TIMPs, suggesting that the osteoclast-stimulating activity of TIMPs cannot be ascribed to merely their inhibitory effect on matrix metalloproteinases.

Acetamides↗
PubMed1999

Chromosomal mapping of two RBP-J-related genes: Kyo-T and RBP-L.

We have recently isolated two genes encoding proteins which have either homology or affinity to RBP-J, a transcription factor involved in Notch signaling. Kyo-T interacts with RBP-J and possibly regulates the function of RBP-J. RBP-L has a highly homologous region with RBP-J but the function of RBP-L is unknown. Fluorescence in situ hybridization analysis of human metaphase chromosomes localized Kyo-T and RBP-L to Xq26 and 20q12-13.1, respectively.

Base Sequence↗
PubMed1999

Thoracoscopic resection of the lung with the ultrasonic scalpel.

We used an ultrasonic scalpel, the Harmonic Scalpel (Ethicon Endo-Surgery, Cincinnati, OH), for limited thoracoscopic resection of the lung in 30 consecutive patients. There were no problems with bleeding in any of the 30 patients. After resection with Harmonic Scalpel the lung was closed with absorbable sutures. In 10 patients the operation was converted to lobectomy, and lymph node dissection was done because intraoperative histopathologic examination revealed lung cancer. Postoperative complications were not observed in the remaining 20 patients who had limited resection only. The Harmonic Scalpel is a useful tool for partial lung resection procedures.

Endoscopy↗
PubMed1999

Efficacy and safety of extended thymectomy for elderly patients with myasthenia gravis.

BACKGROUND: The number of elderly patients who are diagnosed as myasthenia gravis (MG) is increasing in Japan. Although several factors affecting thymectomy have been well documented, few studies have focused on the efficacy and safety of thymectomy for elderly patients older than 60 years. METHODS: We evaluated 94 patients with MG who underwent extended thymectomy, and divided them into two groups: patients younger than 59 years and patients older than 60 years. Preoperative patient data, pathology of the thymus, complications, and clinical outcome were evaluated. RESULTS: In 69 young patients and 25 elderly patients, we observed no significant differences between the two groups with regard to preoperative data. Thymic hyperplasia was present in 45% of the young group and 16% of the elderly group. Remission and improvement rate were 40% and 57% in the young group and 8% and 75% in the elderly group, respectively. There were no serious complications, except one early death due to gastrointestinal bleeding in the elderly group. CONCLUSIONS: We conclude that thymectomy is a safe and effective alternative for elderly patients with MG.

Adolescent↗
PubMed1999

Hypolipidemic effect of NK-104, a potent HMG-CoA reductase inhibitor, in guinea pigs.

The hypolipidemic effect of NK-104 and its mechanisms of action (effects on hepatic sterol synthesis, low density lipoprotein (LDL)-receptor expression and very low density lipoprotein (VLDL) secretion) were studied in guinea pigs using simvastatin as a reference substance. There was a dose-dependent and significant reduction of both plasma total cholesterol (17.4, 24.5 and 45.3% at 0.3, 1 and 3 mg/kg, respectively) and triglycerides (21.1 and 32.2% at 1 and 3 mg/kg, respectively) after 14-day administration of NK-104. Simvastatin at 30 mg/kg lowered plasma total cholesterol (25.0%) but not triglyceride levels. NK-104 (3 mg/kg) and simvastatin (30 mg/kg) inhibited hepatic sterol synthesis by approximately 80%, 3 h after dosing, and enhanced LDL receptor binding-capacity of liver membranes 1.5-fold after 14-day dosing. The former group accelerated LDL clearance somewhat more markedly than the latter, and increased fractional catabolic rate 1.8-fold (vs. 1.4-fold). Furthermore, only the NK-104 (3 mg/kg) suppressed VLDL secretion into the liver perfusate (triglyceride. 19.9%; apoB, 24.2%) with extensive reduction of hepatic sterol synthesis caused by prolonged action. These results indicate that NK-104 and simvastatin at 10 times the dosage of the former, similarly enhances hepatic LDL receptor; however, only NK-104 with prolonged action suppresses VLDL secretion to show higher cholesterol-lowering potency and triglyceride-reducing effect.

Animals↗
PubMed1999

Evaluation of preoperative and intraoperative arterial stimulation and venous sampling for diagnosis and surgical resection of insulinoma.

BACKGROUND: The precise intraoperative localization of insulinoma is essential for successful surgical treatment. In addition to various imaging modalities developed recently, arterial stimulation and venous sampling (ASVS) has also been used for tumor localization. METHODS: Preoperative and intraoperative ASVS procedures were performed in 6 patients with insulinoma. Intraoperative ASVS was performed before and after tumor resection. Immunoreactive insulin (IRI) concentrations and the IRI ratio (IRI concentration at each time interval after calcium injection/baseline IRI concentration) were determined by the conventional or a quick IRI method. RESULTS: The site of the tumor was identified preoperatively in all patients. The peak of the IRI ratio varied widely, but setting the cutoff value at 3.0 clearly differentiated peak IRA ratios in feeding arteries from those of nonfeeding arteries. Intraoperative ASVS showed a similar elevation of IRI levels, but the elevation disappeared after tumor resection in all but 1 patient. In 2 patients, resection of the tumor was confirmed during surgery by measuring IRI levels by the quick IRI method. CONCLUSIONS: A combination of ASVS and conventional imaging modalities is useful for precise localization of insulinoma. Resection of the tumor can be confirmed intraoperatively by comparing IRI levels associated with preoperative and postresective ASVS.

Adult↗
PubMed1999

Cerebrospinal fluid cytokine levels and dexamethasone therapy in bacterial meningitis.

OBJECTIVES: cerebrospinal fluid (CSF) levels of interleukin (IL)-1 beta and tumor necrosis factor (TNF) alpha were measured to assess the effect and application of dexamethasone (Dex) therapy for bacterial meningitis. METHODS: associations between clinical findings and CSF parameters were first investigated, and prognosis was compared between 25 patients with Dex and 12 without Dex therapy. RESULTS: patients with the presence of disturbed consciousness showed higher CSF levels of TNF alpha (mean: 3015 pg/ml) or protein (mean: 215 mg/dl) than those without it (both, P < 0.O5). Simultaneous increase of TNF alpha (> 1000 pg/ml) and protein (> 100 g/dl) was observed in 80%, of patients with profoundly disturbed consciousness. Patients with Dex therapy presented higher TNF alpha/protein levels at diagnosis than those without Dex therapy (P < 0.05). Despite worse conditions at diagnosis, only one of 14 Dex-treated patients whose initial CSF TNF alpha levels exceeded 1000 pg/ml developed deafness. On the other hand, two of four patients without Dex therapy who had the same TNF alpha level suffered from psychomotor retardation. The differences in the frequency of sequelae between those with and without Dex therapy were significant in patients showing high TNF alpha level (P < O.05), but not in those showing high CSF levels of IL-1 beta or protein. The logistic regression analysis indicated that high CSF protein level (P < O.0001), or no Dex therapy (P=0.0001) was the independent risk factor for sequelae. CONCLUSIONS: although the study number was small, our observations suggested that CSF TNF alpha/protein levels reflected the neurologic severity, and implied that early Dex therapy might be beneficial for patients with prominently high TNF alpha levels.

Adolescent↗
PubMed1999

Human monoclonal antibody 28K29 highly reactive with lung adenocarcinomas of all grades of differentiation and with large cell carcinomas.

Human monoclonal antibody (mAb) 28K29 was previously established by fusing regional lymphocytes from a lung adenocarcinoma patient with human-mouse heteromyeloma. This mAb was shown to have an antigen localized in the membrane and cytoplasm of lung cancer cells. This mAb was investigated for reaction with tissue sections from formalin-fixed paraffin-embedded blocks from 100 patients with lung cancer. The mAb 28K29 reacted with 83% (5/6) of the well-differentiated, 79% (22/28) of the moderately-differentiated, and 67% (4/6) of the poorly-differentiated lung adenocarcinoma sections. The mAb also reacted with 35% (14/40) of the squamous cell carcinoma sections, 70% (7/10) of the large cell carcinoma sections, and 20% (2/10) of the small cell carcinoma sections. In Western blot analyses, a broad band at a molecular weight of approximately 600 kDa was detected in extracts from the lung cancer tissues positive for immunohistostaining with the mAb 28K29. The results of the study suggest that the expression of the 28K29 antigen is independent of the histological differentiation grade in lung adenocarcinoma and that this antigen might be a useful marker for detection of both large cell carcinoma and adenocarcinoma of the lung as well as for investigation of the putative transition of large cell carcinoma to adenocarcinoma proposed by Yesner.

Adenocarcinoma↗
PubMed1999

Some observations on the direction of scratch marks.

This study consists of two parts. In the first we recorded 1696 scratch marks seen on 69 pruritic patients. The scratch marks followed a consistent pattern on the skin, which was independent of the cause of the itching. The most striking feature was a longitudinal alignment on the limbs. Next we tried to relate our findings to experimental work that suggests that itching is extinguished most effectively by counterstimuli applied within the same dermatomal segment. If this is the case, sufferers from itchy skin diseases might be expected to scratch itchy points on their skin using strokes directed along dermatomal lines, thereby gaining maximal relief. We used the data obtained during the first part of our study to test this possibility. Fifty-one percent of the scratch marks analyzed ran at an angle of less than 20 degrees to the nearest interdermatomal line (significantly higher than the 22.5% expected by chance). However the tendency for scratch marks to run along dermatomal lines was confined to the limbs. In addition, the preferred scratch directions of a group of nonitchy subjects, not driven by the need to alleviate actual itching, coincided closely with the pattern of scratch marks seen on the itchy patients. The direction of scratch marks may therefore be determined as much by mechanical factors affecting the ease of scratching as by the distribution of dermatomes.

Adolescent↗
PubMed1999

Detecting expression of keratins 8/18 in human HaCaT keratinocytes.

Differences in treatment solution affect the efficiency of keratin extraction in cultured human squamous cell carcinomas, malignant melanomas, and melanocytes. Using an aqueous solution that is excellent for cultured cells, we focused this study on the expression of keratin subunits in the spontaneously immortalized human keratinocyte cell line HaCaT. We extracted several keratin (K) subunits, namely K4, K7, K8, K15, K17, and K18, and ATP synthase alpha-chain, in addition to those previously reported by Boukamp et al. (J Cell Biol 1988;106:761-771) in human HaCaT keratinocytes. In particular, K8 and K18 subunits, which are related to tumorigenesis, may be very important subunits within the specificities of immortalized HaCaT cells. Vimentin, which is frequently co-expressed in cultured epithelial cell lines, was not expressed.

Cell Line, Transformed↗
PubMed1999

Objective scratch monitor evaluation of the effect of an antihistamine on nocturnal scratching in atopic dermatitis.

We previously reported a simple and easy-to-use device, Scratch Monitor for evaluation of nocturnal scratching. In the present study, the effect of an antihistamine (azelastine hydrochloride) on atopic dermatitis was investigated using this device. In 40 patients with atopic dermatitis, nocturnal scratching was measured by the monitor, when taking the drug and while off medication. Neither the 'sleeping time' nor the 'pre-asleep time' differed significantly, but there was a significant difference in 'scratch rate', 'minute scratch records', 'hourly awake number' and 'awake rate', which indicated that this drug alleviated nocturnal scratching and sleep disturbance. The difference was most prominent especially in patients with a serum IgE > or = 1000 IU/ml as well as in patients with mild symptoms and normal serum lactate dehydrogenase levels. The drug was more effective for nocturnal scratching in the early period, when the 'sleeping time' was divided into three equal parts (early, mid and late periods) and each period was compared.

Adolescent↗
PubMed1999

Radioimmunotherapy of human glioma xenografts in nude mice by indium-111 labelled internalising monoclonal antibody.

The potential of 111Indium (111In)-labelled internalising anti-integrin alpha 3 antibody GA17 in the radioimmunotherapy of human glioblastoma xenografts in nude mice was investigated. A radioisotope retention assay showed a rapid release of radioiodine from the glioblastoma cells after the binding of 125I-GA17, whilst 111In-GA17 was retained in the cells for a longer time period. The glioblastoma xenografts showed a high and prolonged uptake of 111In-GA17, and tumour uptake of 125I-GA17 was lower and decreased with time. In the mice which received two injections of 18.5 MBq of 111In-GA17, the growth of the subcutaneous tumour was significantly suppressed compared with the untreated group and mice injected with an 111In-labelled control antibody. These results indicate that GA17 was internalized into the glioblastoma cells and that 111In was retained within the cancer cells. The injection of a high-dose of 111In-GA17 can suppress the growth of tumour xenografts in nude mice.

Animals↗
PubMed1999

Successful tracheal transplantation using cryopreserved allografts in a rat model.

OBJECTIVES: The purpose of this study was to determine the appropriate cryopreservation period of tracheal allografts based on morphological and immunological findings and to test the possibility of tracheal transplantation in rats using cryopreserved allografts without immunosuppression. METHODS: Morphological and immunological studies were performed to compare the differences between non-cryopreserved grafts and cryopreserved grafts. Orthotopic tracheal transplantation using cryopreserved allografts, non-cryopreserved allografts, and non-cryopreserved autografts was performed and the rejection score of each group was evaluated. RESULTS: Epithelial cells were lost when the grafts were cryopreserved for more than 20 days. Immunohistochemical staining of the trachea revealed that the MHC classII antigen was expressed on normal epithelium. These findings suggest that cryopreservation for more than 20 days decreased the antigeneicity of allografts because of epithelial desquamation. All rats that received allografts cryopreserved for more than 20 days survived until the scheduled sacrifice day. Microscopically, cryopreserved allografts that had been preserved for more than 20 days had a significantly lower rejection score than that of non-cryopreserved allografts (P < 0.05). CONCLUSIONS: We conclude that the appropriate period for cryopreservation of allografts would be 20 days or more, because cryopreservation for more than 20 days depleted epithelium, which possessed the MHC classII antigen. Therefore, a longer period of cryopreservation decreases the antigeneicity of allografts. Rat tracheal transplantations using cryopreserved allografts is possible without immunosuppression when the grafts have been cryopreserved for more than 20 days.

Animals↗