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Biomedical subjects

K Itoh

Publications and source records attributed to K Itoh.

At least 487 records · Page 27Linked to original sources

Effect of 10% phosphoric acid conditioning on the efficacy of a dentin bonding system.

The efficacy of a commercial total-etch wet-bonding dentin bonding system and the effect of conditioning using 10% phosphoric acid both on the Ca-content in the substrate dentin and on the efficacy of the experimental contraction gap-free dentin bonding system were evaluated by measuring the wall-to-wall polymerization contraction gap width of a commercial light-activated resin composite filled into a cylindrical cavity prepared in extracted human dentin. The Ca-content in the dentin was measured with an EDS. Complete marginal adaptation was obtained only in the experimental contraction gap-free dentin bonding system group. The Ca-content in the dentin was rapidly reduced by the 10% phosphoric acid conditioning. It was concluded that the dentist should not decalcify the dentin cavity wall possibly by using a dentin conditioner such as 10% phosphoric acid because the resin composite paste is apt to separate easily from the decalcified dentin cavity wall during polymerization.

Acid Etching, Dental↗

Marginal adaptation of commercial compomers in dentin cavity.

The dentin cavity adaptation and setting characteristics of four commercial compomers were evaluated by measuring the wall-to-wall contraction gap width in the cylindrical dentin cavity and measuring the compressive strength for a maximum of 14 days after setting. The dentin cavity wall was pretreated by the dentin adhesives according to each manufacturer's instructions or the experimental contraction gap-free dentin bonding system. Complete marginal integrity was obtained in only one compomer and two resin composites which were combined with the experimental dentin bonding system. The compressive strength of two resin composites and two compomers ten minutes after setting was comparable to that after 14 days which indicated that the compomers exhibited setting characteristics as rapidly as the resin composite. It was concluded that a high efficacy dentin bonding system is required for commercial compomers to prevent gap formation during irradiation caused by the rapid setting shrinkage.

Analysis of Variance↗

2-HEMA-free dentin bonding system to prevent contraction gap.

The effects of 2-hydroxyethyl methacrylate (2-HEMA) both in the primer and in the commercial dentin bonding agent on the efficacy of the dentin bonding system was evaluated by measuring the polymerization contraction gap width of a commercial resin composite restored in a cylindrical dentin cavity prepared in an extracted human molar. Contraction gap formation was prevented in the group of the EDTA-conditioning followed by glyceryl mono-methacrylate, ethylene glycol and 1,6-hexanediol priming regardless of the 2-HEMA content in the dentin bonding agent containing 10-methacryloxydecyl dihydrogen phosphate. However, gap formation could not be prevented completely by the 2-HEMA priming. Therefore, it was possible to conclude that 2-HEMA was neither essential in the primer nor in the dentin bonding agent because of its low bonding efficacy and the resulting side effects on skin tissue as a delayed allergic reaction.

Dental Bonding↗

Decreased expression of cold-inducible RNA-binding protein (CIRP) in male germ cells at elevated temperature.

Physiological scrotal hypothermia is necessary for normal spermatogenesis and fertility in mammals. Cirp is a recently identified cold-inducible RNA-binding protein that is inducible at 32 degrees C in mouse somatic cells in vitro. Cirp is constitutively expressed in the testis of mouse and structurally highly similar to RBM1, a candidate for the human azoospermia factor. To elucidate the role played by Cirp in spermatogenesis, we investigated its expression levels during spermatogenesis and after heat stress. In the mouse testis, cirp mRNA was detected in the germ cells, and the level varied depending on the stage of differentiation. Also, a high level of Cirp protein was detected immunohistochemically in the nucleus of primary spermatocytes. Expression of Cirp was decreased in the GC-2spd(ts) mouse germ cell line when culture temperature was raised from 32 degrees C to 37 degrees C. When mouse testis was exposed to heat stress by experimental cryptorchidism or immersion of the lower abdomen in warm (42 degrees C) water, the expression of Cirp was decreased in the testis within 6 hours after either treatment. In human testis with varicocele analyzed immunohistochemically, germ cells expressed less Cirp protein than those in the testis without varicocele. These results demonstrated that CIRP expression is down-regulated at elevated temperature in male germ cells of mice and humans. Analysis of Cirp expression in the testes will help elucidate the molecular mechanisms leading to male infertility.

Adult↗

[The influence of the physician's speciality on ambulatory "essential laboratory tests"].

The purpose of this study was to examine the influence of a physician's speciality on the choice of "essential laboratory tests" and their response to the test results. A retrospective case-control study was conducted in divisions of the Department of Internal Medicine in Jichi Medical School Hospital. Twenty-seven parameters were evaluated in 213 outpatients (mean age 47 +/- 17 years; 53% female). Forty-three percent (2443 of 5751) of the tests were conducted by the physician under study and 10.5% (257 of 2443) of their tests were abnormal. The physician's speciality influenced the choice of the ambulatory medical examinations and their response to abnormal tests. Physicians tend to be more sensitive to the abnormality of tests related to their specialty. Hence, it is necessary to constitute guidelines on the response to abnormal "essential laboratory tests".

Adolescent↗

Active immunotherapy with ultraviolet B-irradiated autologous whole melanoma cells plus DETOX in patients with metastatic melanoma.

Our objective was to determine the clinical activity, toxicity, and immunological effects of active immunotherapy using UVB-irradiated (UVR) autologous tumor (AT) cells plus adjuvant DETOX in metastatic melanoma patients. Eligibility included nonanergic patients fully recovered after resection of 5 or more grams of metastatic melanoma. Treatment consisted of intradermal injections of 10(7) UVR-AT plus 0.25 ml of DETOX every 2 weeks x 6, then monthly. Peripheral blood mononuclear cells (PBMCs) were harvested for cytotoxicity assays, and skin testing was performed for delayed-type hypersensitivity (DTH) determinations before the first, fourth, seventh, and subsequent treatments. Forty-two patients were treated, 18 in the adjuvant setting and 24 with measurable disease. Among the latter group, there were two durable responses in soft-tissue sites and in a bone metastasis. Treatment was well tolerated. Thirty-five patients were assessable for immunological parameters; 10 of these patients, including the 2 responders, demonstrated early induction of PBMC cytotoxicity against AT cells that persisted up to 10 months on treatment before falling to background levels. In five of seven patients, the fall-off heralded progressive disease. Late induction of a weak DTH reaction to AT cells was observed in eight patients. Active immunotherapy with UVR-AT + DETOX had modest but definite clinical activity in advanced melanoma. The induction of both PBMC cytotoxicity and DTH reactivity to AT cells supported a specific systemic immune effect of treatment, although the former more closely followed disease course in this study.

Adjuvants, Immunologic↗

Accumulation of iodine-131-iodocholesterol in renal cell carcinoma adrenal metastases.

Adrenocortical scintigraphy is a useful technique for differentiating between types of nonhyperfunctioning adrenal masses. Metastatic tumors do not normally accumulate radioiodocholesterol and show discordant uptake on scintigrams. We present two patients who showed accumulation of 131I-6beta-iodomethyl-19-norcholesterol (NP59) in the adrenal metastases from renal cell carcinoma. In one patient with bilateral adrenal metastases, accumulation in the primary tumor as well as adrenal metastases was demonstrated. The adrenal metastases in both patients were resected and were histologically proven to be metastases from clear-cell renal carcinoma. Accumulation of NP59 in metastatic adrenal tumors, although a very rare finding, suggests a pitfall in the differential diagnosis of adrenal cortical tumors.

19-Iodocholesterol↗

Effect of beta-sitosterol on ultrastructure of liver cells in young and aged mice.

The effects of beta-sitosterol on liver ultrastructure were studied using young and aged male mice. Both groups of mice were fed a beta-sitosterol or a control diet. The beta-sitosterol diet contained 1% beta-sitosterol. Ultrastructural differences in the liver cells were evident between two groups fed the two diets. The number of peroxisomes was significantly greater in the liver cells of both young and aged mice fed the beta-sitosterol diet than in those fed the control diet. There were also significant differences in the maximum length of lipid droplets between the young and aged mice fed the beta-sitosterol diet. These results suggest that beta-sitosterol affects liver ultrastructure, and that some ultrastructural differences in liver cells exist between young and aged mice fed the beta-sitosterol diets.

Aging↗

[Acute promyelocytic leukemia relapse as leukemia cutis shortly after complete remission with all-trans retinoic acid].

A 56-year-old man was admitted to our hospital in September, 1996. Chromosomal translocation (15; 17) and a PT-PCR study for PML-RAR alpha mRNA were positive in bone marrow aspirates, and acute promyelocytic leukemia was diagnosed. After CR was obtained with all-trans retinoic acid (ATRA) followed up with chemotherapy, the RT-PCR became negative. When he was readmitted in April, 1997, skin eruption on his chest and extremities were observed. Specimens taken for biopsy revealed leukemia cutis, and RT-PCR became positive in the same specimen. Bone marrow PT-PCR was also positive without abnormal promyelocytes. Although he was treated with oral ATRA 80 mg/day again, no significant improvement in leukemia cutis was noted. After combined therapy with Ara-C and acularubicin, skin eruption disappeared and bone marrow RT-PCR became negative. A second CR was then obtained. Although it is unknown whether the administration of ATRA is related to extramedullary relapse or not, we recommend combined chemotherapy for such cases.

Humans↗

Thallium-201 scintigraphy to predict therapeutic outcome of iodine-131 therapy of metastatic thyroid carcinoma.

UNLABELLED: We studied the relationship between 201Tl uptake and the efficacy of radioiodine therapy in thyroid carcinoma. METHODS: Forty-four patients with metastases of well-differentiated thyroid carcinoma received 201Tl scintigraphy within the 2 mo before their initial 131I therapy. Patients were classified into two groups according to the tumor-to-background (T/B) ratio on the late 201Tl scan: high 201Tl uptake (T/B > or = 2.1) and low 201Tl uptake (T/B < 2.1). The therapeutic outcome was judged by the percent reduction in the tumor diameter at 6 mo after the treatment. The treatment was defined as effective when the tumor showed more than 50% reduction in the tumor diameter. The patients in whom radioiodine was ineffective were followed up to determine if the tumor showed further growth. RESULTS: Of the 44 patients, 25 had high 201Tl uptake and 19 had low 201Tl uptake. The therapy was effective in 15 patients and was ineffective in 29. All the patients in whom radioiodine was effective had low 201Tl uptake. On the other hand, 25 of 29 patients in whom radioiodine was ineffective had high 201Tl uptake. Eight patients, in whom radioiodine was ineffective despite good 131I uptake, had high 201Tl uptake. There were no significant differences in the positive predictive value and the negative predictive value for effective treatment between 201Tl scintigraphy and therapeutic dose 131I scintigraphy. Among the 25 patients in whom radioiodine was ineffective and who had high 201Tl uptake, the tumor diameter increased in 7 (28%). However, none of the tumors with low 201Tl uptake increased in size during the follow-up period. CONCLUSION: Thallium-201 scintigraphy has a high predictive value for the efficacy of radioiodine therapy in metastatic thyroid carcinoma. Thus, it is helpful in determining the indication for radioiodine therapy and it seems to be an adjunct to tracer dose 131I scintigraphy.

Adenocarcinoma, Follicular↗

Calcified pseudoaneurysm of the left ventricle.

Left ventricular pseudoaneurysm following acute myocardial infarction generally has an extremely poor prognosis without surgical repair. A rare case of long term survival for 23 years following cardiac rupture with subsequent development of a left ventricular pseudoaneurysm after acute myocardial infarction is reported. The patient suffered acute inferoposterior myocardial infarction in July 1974 at the age of 58 years. Clinical course and findings obtained on reassessment in 1992 (transesophageal echocardiography, chest computed tomography and left ventriculography) confirmed a left ventricular pseudoaneurysm. The patient refused surgical resection of the lesion, but remained alive and well in 1997 (81 years old). In this case, it is considered that containment of hemorrhage by pericardial adhesion prevented immediate tamponade and sudden death.

Aged↗

Acute idiopathic thrombocytopenic purpura presenting a high serum level of immunoglobulin E and eosinophilia in an elderly patient.

An 80-year-old Japanese woman having acute idiopathic thrombocytopenic purpura presented with an increased serum level of IgE and eosinophilia. No evidence for allergic, parasitic, collagen or malignant diseases was observed. The disease subsided with prednisolone therapy and she has been in remission for three years. Our case is one of the oldest ITP patients with increased IgE and eosinophilia.

Acute Disease↗

[Dissecting aneurysm of the extracranial vertebral artery causing TIA: a case report].

Spontaneous dissecting aneurysm of the extracranial vertebral artery is not frequent. We report a case of dissecting aneurysm of the left extracranial vertebral artery causing TIA. A 44-year-old man was admitted to our hospital with severe occipitalgia of sudden onset on Dec. 21, 1995. On admission, he presented with left hemiparesis and left hemidysesthesia. CT scan and SPECT showed no abnormal findings. His neurological deficits completely improved on the following day. Initial cerebral angiography performed on Dec. 27, 1995 showed pearl and string sign at V3 segment and irregular stenosis at V2 segment suggesting a dissecting aneurysm. We treated conservatively. Repeated angiography performed four weeks after the onset showed resolution of the stenosic lesion and disappearance of the aneurysm. We discussed diagnosis and etiology and treatment of dissecting aneurysm of the extracranial vertebral artery.

Adult↗