Biomedical subjects

T Ichikawa

Publications and source records attributed to T Ichikawa.

770 records · Page 43Linked to original sources

PubMedDate not supplied

Production of cyclic nucleotides from normal human brain.

Concentrations of cyclic AMP and cyclic GMP in arterial and internal jugular venous (IJV) blood were determined at the resting wakeful state in thirty surgical patients without neurological deficits. The levels of cyclic AMP in artery and IJV were 32.1 +/- 3.0 and 40.0 +/- 4.1 pmol/ml (means +/- standard errors), respectively, while those of cyclic GMP in artery and IJV were 12.2 +/- 2.7 and 14.4 +/- 3.0 pmol/ml, respectively. Concentrations of both cyclic nucleotides in IJV were significantly higher (P less than 0.001) than those in artery. IJV-arterial differences for cAMP and cGMP were 7.9 +/- 1.7 and 2.1 +/- 0.5 pmol/ml, respectively. The results indicate that both cyclic nucleotides are constantly produced and released from the normal human brain.

Adolescent↗

PubMedDate not supplied

The effects of extreme hemodilutions on the autoregulation of cerebral blood flow, electroencephalogram and cerebral metabolic rate of oxygen in the dog.

The effects of profound (hematocrit value, Ht 20%) and extreme (Ht 5%) hemodilutions on the relationship between the mean arterial pressure (MAP) and the cerebral blood flow (CBF) were studied in pentobarbital-anesthetized dogs. A regression line was found between the CBF and Ht values during normotensive hemodilution (MAP 100 torr): CBF (ml/100g X min) = -98.9 log Ht (%) + 195.5 (p less than 0.001). The CBF was increased by hemodilution, but the range of its autoregulation was narrowed, suggesting a progressive susceptibility of CBF to blood pressure with hemodilution. The electroencephalogram (EEG) was not significantly changed by hemodilution within the range of the CBF autoregulation, below which it became slowed. In contrast, the cerebral metabolic rate of oxygen (CMRo2) was decreased by hemodilution even within the range of the CBF autoregulation, while there were no significant differences in CMRo2 values between MAPs of 100 and 40 torr. Thus, the brain function in terms of the EEG seemed to correlate more with the autoregulatory mechanism of the CBF than with the CMRo2 value in the hemodiluted states.

Animals↗

PubMedDate not supplied

[Clinical evaluation of basic fetoprotein in bladder cancer].

PURPOSE: The early diagnosis of bladder cancer allows for effective local treatment and optimizes the success of surgical therapy. Basic fetoprotein (BFP), measured using a rapid latex immuno-agglutination method, was introduced for the detection of transitional cell carcinoma. The objective of this study was to determine whether there was a correlation between urine BFP level and the grade or stage of bladder cancer, and whether the level could serve as a biochemical marker of bladder cancer. MATERIALS AND METHODS: Single voided specimens were obtained from 66 patients with confirmed or suspicious bladder cancer on cystoscopy, urine cytology or BFP. Each sample was divided into 3 aliquots of which 1 was for urine analysis, 1 was tested for BFP according to latex immunoagglutination method and 1 was sent for cytological examination. All patients subsequently underwent bladder biopsy. RESULTS: There were 54 (82%) patients with biopsy confirmed bladder cancer and 12 (18%) with benign conditions of the bladder. Overall sensitivity with BFP and urine cytology was 38.9% and 48.1% respectively. Specificity was 58.3% and 75.0%, and positive predictive value was 80.8% and 89.7%, respectively. The positive rate of BFP and cytology was higher in invasive cancer (75% and 100%, respectively) than in superficial cancer (36% and 28%). There was no correlation between BFP level and tumor grade, while cytology had a strong association. Linear regression analysis showed the significant correlation between BFP level and tumor size (r = 0.695, p < 0.0001). The detection rate of bladder cancer was higher by the combination of BFP and cytology than by using alone. CONCLUSIONS: BFP in conjunction with urine cytology can increase the detection rate of bladder cancer. But BFP alone cannot be used as a screening test for bladder cancer.

Adult↗

PubMedDate not supplied

Fast dynamic MRI of aortic dissection: flow assessment by subsecondal imaging.

PURPOSE: The aim of this study was to evaluate fast dynamic MRI, which consists of a subsecondal MRI sequence combined with a rapid contrast medium infusion technique, in examining clinical cases of aortic dissection. MATERIALS AND METHODS: The subjects consisted of 27 patients with aortic dissection. Turbo-FLASH imaging of the aorta was conducted to obtain 50 image frames within 40 seconds. RESULTS: Recognition of the intimal flap and differentiation of the true channel from the false channel was easily accomplished in all 15 patients with a patent false channel. The entry site was detected in 13 of 15 patients. Differentiation of slow flow from thrombus in the false channel was possible in all 27 cases, and the relationship between the lesion and the main branches of the aortic arch was identified in 26 of 27 cases. CONCLUSION: Fast dynamic MRI may provide a large amount of information that is useful for the diagnosis of aortic dissection.

Aortic Dissection↗

PubMedDate not supplied

Local recurrence of breast cancer demonstrated on 99mTc-MIBI scintigraphy.

We present a postmastectomy patient in whom a mass was palpated in the chest wall. It appeared to be difficult to determine whether the chest wall mass was local recurrence of breast cancer or granulation induced by mastectomy on computed tomography (CT). The mass was successfully demonstrated on 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) scintigraphy as an area of increased accumulation, and was considered to be a recurrent tumor. Surgical resection was performed, and the mass was histopathologically proven to be recurrence. 99mTc-MIBI scintigraphy may contribute to the detection of local recurrence or distant metastasis in addition to the diagnosis of primary breast cancer and axillary metastasis.

Breast Neoplasms↗

PubMedDate not supplied

Influence of occlusal scheme on the pressure distribution under a complete denture.

PURPOSE: The purpose of this study was to estimate which occlusion offers the best conditions of pressure distribution on the supporting structure under a complete denture when crushing food. MATERIALS AND METHODS: Simulated maxillary and mandibular complete dentures with three different posterior occlusal schemes--fully balanced occlusion, lingualized occlusion, and monoplane occlusion--were fabricated. Eight pressure transducers were placed in the basal surface of a mandibular denture. The pressure distribution on the mandibular edentulous mouth model with 1.5-mm-thick artificial tissue under a complete denture was recorded when crushing three different foods: soft food (kamaboko), peanuts, and carrot. The mean pressure values at each measurement point and the force required for each test were compared using one-way analysis of variance with P < or = 0.05 representing statistical significance. RESULTS: The required force for crushing a soft food or carrot in the left molar region in monoplane occlusion was significantly larger than that required in fully balanced occlusion or lingualized occlusion. In crushing soft food, fully balanced occlusion showed significantly higher pressure values on the working side than in monoplane occlusion or lingualized occlusion. In crushing the carrot, the pressure values in fully balanced occlusion and in lingualized occlusion were significantly lower than those in monoplane occlusion. CONCLUSION: These results demonstrate that with fully balanced occlusion and lingualized occlusion a large occlusal force is not needed for crushing hard food, and the stress to the supporting tissues is smaller than with monoplane occlusion.

Alveolar Process↗

PubMedDate not supplied

Effect of concurrent intra-arterial infusion of platinum drugs for patients with stage III or IV uterine cervical cancer treated with radical radiation therapy.

PURPOSE: The purpose of this study was to explore the effect of concurrent intra-arterial infusion of platinum drugs in patients with stage III or IV uterine cervical cancer treated with radical radiation therapy. PATIENTS AND METHODS: Thirty-three patients with advanced (stage IIIA, 2; IIIB, 28; IVA, 3) uterine cervical squamous cell carcinoma were randomized into a concurrent intra-arterial infusion of platinum drugs with radiation therapy (IAPRT) group (18 patients) and a radiation therapy alone group (15 patients). After altering intrapelvic blood flow by embolization of the superior and inferior gluteal arteries under pelvic angiography, intra-arterial infusion of platinum drug through catheters inserted into both internal iliac arteries was performed concurrently with radiation therapy. One-shot infusion of cisplatin (100 mg/m2) twice with a 2- to 3-week interval was performed in eight patients, weekly infusion of carboplatin (100 mg/m2) via a reservoir five to six times was performed in four patients, and daily shot of cisplatin (10 mg/body) or 21 days via a reservoir was performed in six patients. Radiation therapy consisted of external-beam irradiation of 50 Gy/25 fractions/5 weeks for the whole pelvis with midline block after 30 Gy and intracavitary high-dose-rate brachytherapy using tandem and ovoids of 24 Gy/4 fractions/4 weeks to point A. RESULTS: The local complete response rate of the IAPRT group was 94% and was significantly higher than that of the radiation therapy group (67%). There were no significant differences in local response in the three drug delivery methods. Two- and 5-year overall survival rates were 54.5% and 44.4% in the IAPRT group, and 74.5% and 50.0% in the radiation therapy group, respectively. There was no significant difference between the two groups. In the IAPRT group, grade 3 or 4 acute bowel complications were seen in 33% of patients, grade 3 or 4 late bowel complications were seen 44%, and grade 3 or 4 myelosuppression was seen in 33%, and these complications were seen more in the IAPRT group than in the radiation therapy group and caused death in some patients. CONCLUSIONS: IAPRT had a better local response than radiation therapy but showed no proof of control over recurrence and had a poorer survival than radiation therapy. There were many local recurrences and distant metastases, contrary to the better first response of the IAPRT group over the radiation therapy group. Complications of the IAPRT group were very severe and made the patient's performance status and prognosis worse than in the radiation therapy group. We need to design some methods to decrease these complications to make use of the good local response acquired with IAPRT. Furthermore, we should re-examine the indication of IAPRT in patients with a large tumor because local recurrence and distant metastasis would be inevitable.

Adenocarcinoma↗

PubMedDate not supplied

Phosphorylation status and function of P53 are inversely related to protein kinase C activation.

The role of phosphorylation in the regulation of p53 protein function is little understood. We have addressed the role of protein kinase C (PKC) in the phosphorylation. Exposure to the protein kinase inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7), increased the phosphorylation of wild type p53 protein, whereas exposure to the tumor promoter phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate (TPA), decreased it in vivo following 3 hours incubation with mouse epidermal JB6 cells. Exposure to the c-AMP dependent protein kinase (PKA) activator, forskolin, did not decrease the phosphorylation of p53 protein. In the transient transfection/luciferase reporter transactivation assay, H7 modestly increased the mouse double minute (MDM) 2 reporter transactivation activity of p53 protein after 24 hours treatment, and TPA completely blocked it. These results suggest that the accelerated phosphorylation of wild type p53 protein is inversely related to PKC activation, and that p53 phosphorylation may have some relation to transcription factor function.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMedDate not supplied

Treatment of solitary small hepatocellular carcinoma: consideration of hepatic functional reserve and mode of recurrence.

BACKGROUND/AIMS: Hepatocellular carcinoma (HCC) recurs frequently after initial treatment. The subsequent prognosis varies with the mode of recurrence. Some patients die of hepatic failure even though the HCC is controlled. We consider the clinical stage (CS), using the modified Child-Pugh classification, to be an important factor influencing the prognosis of these patients. METHODOLOGY: To determine the most effective treatment for HCC, we examined 105 patients with solitary small HCC who were followed-up for more than 1 year after initial treatment. All of them were judged to be cured according to imaging or histological studies. The initial treatments were hepatic resection (n = 43), percutaneous ethanol injection therapy (PEIT, n = 33), and percutaneous microwave coagulation therapy (PMCT, n = 29). The modes of recurrence were divided into intrahepatic metastasis (IM) and multicentric occurrence (MO). RESULTS: Prognosis of MO was superior to that of IM in CS I patients, but there was no difference in prognosis between these modes in CS II. The hepatic resection group had more MO recurrences in CS I patients and more IM recurrences in CS II patients. IM developed frequently after PEIT and PMCT, regardless of the CS. Prognosis with hepatic resection was superior to that of the other treatments in CS I patients, but there was no difference in prognosis among the 3 treatment modalities in CS II patients. CONCLUSIONS: These data indicate that hepatic resection is the first choice for treating HCC in CS I patients, and that PEIT or PMCT is preferable for CS II patients.

Aged↗

PubMedDate not supplied

Three-dimensional bone response to commercially pure titanium, hydroxyapatite, and calcium-ion-mixing titanium in rabbits.

Three-dimensional bone response to 3 biomaterials--commercially pure titanium (Ti), hydroxyapatite (HA), and calcium-ion-mixing titanium (Ca-Ti)--embedded in the tibiae of rabbits was examined chronologically. The rabbits were sacrificed at 2, 4, and 8 weeks after implantation, and the percent bone volume around each implant was calculated from the implant surface to each of 4 measurements: 36 microns, 0.25 mm, 0.5 mm, and 1.0 mm in 2 regions (cortical bone and bone marrow regions). Percent bone volume in the cortical bone was consistent, whereas in the bone marrow region, the percent bone volume varied according to implant material, implantation period, and distance from the implant surface. With Ti implants the percent increased gradually up to 8 weeks at each distance, whereas in HA and Ca-Ti implants the percent was largest at 4 weeks and increased closer to the surface. The percent with Ti implants was largest at 36 microns to 0.25 mm. Aspect of bone response to Ca-Ti was its position intermediate between those of HA and Ti. The decrease of the percent at 8 weeks was smaller than HA.

Analysis of Variance↗

PubMedDate not supplied

A case of jugular foramen chordoma with extension to the neck: CT and MR findings.

We describe a case of jugular foramen chordoma with extracranial extension into the carotid, parapharyngeal, and perivertebral spaces through the jugular foramen. Although this type of extension is unusual, the differential diagnosis of head and neck tumors includes unusual extension of chordoma as well as extension of meningioma and neurinoma from the posterior skull base.

Aged↗

PubMedDate not supplied

Determination of total dietary fiber in Japanese foods.

Total dietary fiber was determined in Japanese foods by the Prosky-AOAC method. To accomplish the analyses of unsuitable samples, we introduced a few minor modifications to the versions for (i) seaweed and fruits, (ii) cereals, and (iii) fish and meats. These modified methods were used together with the standard method to obtain results with reasonably good relative standard deviation for 231 foods and 21 groups of mixed foods. In this study, dietary fiber was defined so as not to exclude the nondigestible polysaccharide portions of animal foods. A method was proposed which could estimate more accurately the fiber components of animal foods by measuring the "nondigestible protein" of the fiber sample of the fiber sample by the Biuret colorimetric method, instead of the Kjeldahl method, to avoid deducting the values for aminopolysaccharides. In Japanese diets, the amount of fiber obtained from animals foods was less than 5% of the total intake of dietary fiber.

Dietary Fiber↗

PubMedDate not supplied

Radiographic analysis of a two-piece apatite implant: Part II. Preliminary report of 2-year observation.

Marginal bone height and bone density were evaluated for 2 years after two-piece dense hydroxyapatite implant (Apaceram) placement using standardized radiography and digital image processing. The chronological changes in marginal bone height were divided into three groups: Group I-level was constant or became higher with time; Group II-bone decreased gradually after superstructure placement; and Group III-bone decreased in height rapidly after abutment placement. Bone density around the successful Apaceram implant, especially in the crestal region, increased clearly. The results suggest that bone resorption/formation around the implant is related to occlusal stress, and that adequate occlusal stress should be exerted on the implant at each phase after the implant placement.

Adult↗

PubMedDate not supplied

In vitro study of mandibular implant-retained overdentures: the influence of stud attachments on load transfer to the implant and soft tissue.

This study investigated the occlusal stress distribution to the implant and soft tissue for the implant-retained overdenture. The stress at the molar residual ridge and the strain around the implant were measured on an experimental resin cast using static and dynamic loading. The influence of connecting structures of stud attachments on stress distribution was discussed. The occlusal stress had a tendency to concentrate on the implant, especially in the areas distal to the implant. The modified magnetic attachment system, using a silicone-covered magnet, provided the optimal stress distribution.

Bite Force↗