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Biomedical subjects

M Sakamoto

Publications and source records attributed to M Sakamoto.

At least 433 records · Page 24Linked to original sources
PubMed1994

Early advanced hepatocellular carcinoma: evaluation of CT and MR appearance with pathologic correlation.

PURPOSE: To determine the computed tomographic (CT) and magnetic resonance (MR) imaging appearances of early advanced hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Twenty-seven surgically resected cases of early advanced HCC were studied with CT, CT during arterial portography, CT arteriography, and MR imaging. RESULTS: The sensitivity of standard CT (unenhanced, early, and late CT combined) for the detection of early advanced HCC was 81%, while that of standard MR imaging (T1- and T2-weighted MR imaging combined) was 83%. A nodule-in-nodule appearance was identified in approximately one-third to one-half of cases. Signal behavior of early and advanced components of early advanced HCC followed the expected behaviors of isolated early HCC and isolated advanced HCC, respectively. Tumor size was accurately estimated with standard CT and standard MR imaging. CONCLUSION: More research must be performed to ascertain whether any relationship exists between the different types of HCC and the clinical outcome.

Aged↗
PubMed1994

Hiccuplike response elicited by mechanical stimulation of dorsal epipharynx of cats.

To identify the site for triggering hiccup, we recorded activities from the diaphragm (DIA), posterior cricoarytenoid muscle (PCA) of the larynx, and abdominal muscle (ABD) along with intrapleural pressure (Ppl) in anesthetized spontaneously breathing cats. To directly access the epipharynx and to observe glottic movement, we made a submental opening at the level rostral to the epiglottis. Mechanical stimulation of the epipharynx evoked a fixed motor pattern of hiccup: DIA showed spasmodic discharge, and Ppl exhibited spiky negative pressure swing; phasic (inspiratory) discharge of PCA was inhibited, and glottic adduction was revealed by direct observation; and ABD remained suppressed during this response. Chlorpromazine hydrochloride or CO2 inhalation suppressed the response, and the intensity of the response varied according to phase of the respiratory cycle, being largest at midinspiration and least at midexpiration. These are compatible with clinical data on human hiccup. Mechanical stimulation of various parts other than the epipharynx failed to evoke the hiccuplike response. The triggering site was located in the dorsal wall of the epipharynx overlying the occipital bone. These results indicate that mechanical irritation of the dorsal epipharynx is essential for triggering hiccup.

Animals↗
PubMed1994

Epidermal growth factor concentrations in seminal plasma from patients with hypogonadism--changes after hormone replacement.

Epidermal growth factor (EGF) content in seminal plasma of 17 patients with androgen deficiency (12 Klinefelter's syndrome and 5 hypogonadotropic hypogonadism) was determined before and after hormone replacement. No significant increase of plasma testosterone level was demonstrated after testosterone administration in Klinefelter's syndrome, although the level in 4 of 5 patients with hypogonadotropic hypogonadism reached the normal range. In 16 patients, except 1 with hypogonadotropic hypogonadism with no increase of blood testosterone level, prostate volume increased after hormone therapy, and volumes after treatment were significantly larger than those before treatment. On the other hand, EGF concentration in seminal plasma remained at the pretreatment level in most patients. It is therefore concluded that although the prostate volume increases to almost normal after treatment, prostate function does not improve in most patients, indicating that in patients with hypogonadotropic hypogonadism fertility potential may remain low, even if they obtain normal seminal parameters after treatment.

Adult↗
PubMed1994

Effects of systemic cooling and rewarming on the evoked spinal cord potentials and local spinal cord blood flow in dogs.

Changes in evoked spinal cord potential (ESCP) and in local spinal cord blood flow (local SCBF) were measured simultaneously in eight dogs in the course of systemic cooling and rewarming using a water mattress. PaCO2 was maintained at 35-40 mm Hg (temperature-uncorrected values) by adjusting ventilatory volume every 1 degree C change of esophageal temperature under N2O (60%)-O2-isoflurane (1.15%) anesthesia. Local SCBF and arterial blood pressure decreased and ESCP latencies increased linearly with the decrease in body temperature to 23-24 degrees C. The conductive ESCPs (non-synaptic components) showed temporary augmentation in amplitude before eventual decrease under cooling. These showed a tendency to return to the precooling baselines after the initiation of rewarming. These results demonstrate that conductive ESCPs could be available for intraoperative monitoring of spinal function under hypothermia down to 23-24 degrees C.

Animals↗
PubMed1994

Cadmium stimulation of glycosaminoglycan synthesis by cultured vascular endothelial cells: comparison of various cell types.

We investigated the effect of cadmium on the synthesis of glycosaminoglycans (GAGs) in confluent cultures of vascular endothelial cells derived from bovine aorta. Cadmium markedly increased the incorporation of [3H]glucosamine into GAGs in both the cell layer and the conditioned medium but decreased [35S]sulfate in the cell layer. This suggested that cadmium induced the GAG synthesis by endothelial cells accompanied by a reduction of the sulfation of cell-associated GAGs. Of the tested heavy metals, the [35S]sulfate incorporation in the cell layer was significantly decreased by lead; zinc slightly but significantly increased the [35S]sulfate incorporation; manganese and copper failed to change the [3H]glucosamine and [35S]sulfate incorporation; and the incorporation of [3H]glucosamine was increased only by cadmium. On the other hand, vascular smooth-muscle cells and fibroblastic Balb/3T3 cells responded to cadmium in a way similar to vascular endothelial cells, while fibroblastic IMR-90 cells, Chang liver cells and epithelial LLC-PK1 cells altered the [3H]glucosamine and [35S]sulfate incorporation after exposure to cadmium in different manners. The alteration of GAGs induced by cadmium may be involved in the pathogenesis of the metal.

Animals↗
PubMed1994

Lipase-catalyzed hydrolysis of some racemic 1-acetoxy-2-arylpropanes.

Racemic 1-acetoxy-2-phenylpropane (12) and 1-acetoxy-2-(2-naphthyl)propane (33) were hydrolyzed with lipase at 35-36 degrees C for 2 and 24 h to give predominantly (S)-2-phenyl-1-propanol (11) and (S)-2-(2-naphthyl)-1-propanol (32), respectively. However, racemic 1-acetoxy-2-(1-naphthyl)propane (25) was recovered intact even when the reaction was carried out for 240 h. On the other hand, the enantioselectivities towards racemic 2-phenyl (16), 2-(p-tolyl) (20), 2-(1-naphthyl) (28), and 2-(2-naphthyl) (36) derivatives of 1-acetoxy-2-propanol were very low.

Hydrolysis↗
PubMed1994

Prediction of collapse with magnetic resonance imaging of avascular necrosis of the femoral head.

In order to predict the probability of collapse of a femoral head in which there is avascular necrosis, we used magnetic resonance imaging to evaluate sixty-six hips (fifty patients) in which avascular necrosis was in the early stages and in which collapse of the head was not yet visible. The hips were followed radiographically for an average of forty-nine months (range, sixteen to eighty-four months), and with magnetic resonance imaging for an average of forty-four months (range, twelve to seventy-three months). Twenty-one (32 per cent) of the femoral heads had collapsed by thirty-two months. Of the twenty-three femoral heads in which necrosis involved at least one-fourth of the diameter of the head and encompassed at least two-thirds of the major weight-bearing area, seventeen (74 per cent) had collapsed by thirty-two months.

Adult↗
PubMed1994

Age differences in characteristics of the attention process of electrodermal activity during auditory stimulation.

Age differences in characteristics of the attention process of electrodermal activity during passive and active listening tasks were studied with 43 nursery and 49 primary school children and 38 university students. The procedure included baseline recording, a passive listening task, instruction, and an active listening task. Significant differences in skin conductance response (SCR) were found among the three age groups. The SCR became smaller for the groups of increasing ages only for the active listening task. As the trials progressed, there was a trend in the three age groups for decreasing SCR amplitude during the passive listening task.

Adolescent↗
PubMed1994

[Histological and radiobiological study on adult cases with ataxia telangiectasia].

Ataxia telangiectasia (AT) is a hereditary disease that involves both the immune and nervous system; its pathogenesis is believed to be due to disturbances in DNA repair system. Because children are usually affected, reports concerning adult patients are rare. In the present study, we performed comprehensive clinical, histological, and radiobiological examinations on two adult female siblings, currently 23 and 19 years old. The initial symptom was an ataxic gait, which began in the elder sister at the age of 20 and the younger sister at the age of 18. Both had mild telangiectasia in the bulbar conjunctiva and auricula. The neurological manifestations of both were gaze nystagmus, cerebellar ataxia, hyporeflexia, and vibratory sensation disturbance. Only the elder sister showed stocking type sensory disturbance. The MRI of both patients revealed cerebellar atrophy, especially in vermis. After either X-ray irradiation or bleomycin treatment, fibroblast survival curve showed a marked, dose-dependent declined in both patients compared with normal controls. Similar patterns were observed in both patients. After bleomycin treatment, no differences in the survival ratio of cultured fibroblasts could be found between these adult patients and those observed in younger children with classic AT. Biopsied sural nerves showed a decrease in the number of large myelinated fibers, with a few myelinated axons having relatively thin myelin. There were severe atrophic changes, with regenerative myelinated fibers in the elder sister. In conclusion, both adult patients with delayed onset AT displayed similar bleomycin hypersensitivity in fibroblasts as would be expected in children with AT. Radiobiological examinations and sural nerve biopsy suggest that both disturbed cellular regeneration and atrophic process may play a role in the neural involvement in this disease.

Adult↗
PubMed1994

[Experience of a double Malecot polyurethane intraurethral catheter in patients with dysuria].

We reviewed our experience of using double Malecot polyurethane intraurethral catheters (IUC). Ten patients with dysuria were treated between April 1991 and April 1993. Seven patients with benign prostatic hypertrophy (BPH) were judged as in a high risk group for operation. The three other patients had neurogenic bladder (two had underactive bladder and 1 had overactive bladder). Under local anesthesia, 150 ml of 0.1% Povidone iodine solution was infused into the bladder through a Nelaton catheter. Under guidance by ultrasonography, an IUC was placed into the bladder neck and posterior urethra using the specially designed introduction set. An long-term follow up of the BPH patients, two IUCs were removed for operation and one was exchanged for an indwelling catheter because of deterioration in general condition. In the neurogenic bladder patients, all IUC were removed because of the increase of residual urine, formation of a pseudourethra, or dislocation into the bladder. Side effects were observed in 6 patients such as, urethral bleeding and stone formation in the stent. Erosion and bleeding tendency in the urethral mucosa were shown in the prolonged duration cases. We conclude that a urethral stent is an effective devise for a high risk patient with benign prostatic hypertrophy but we must keep each patient under strict observation for complications during IUC placement.

Aged↗
PubMed1994

[Clinical study on renal pelvic and ureteral tumors].

Thirty five patients with renal pelvic and ureteral tumors were treated at our hospital between 1979 and December 1992. Thirty patients were male and five were female. They ranged in age from 44 to 80 years old (average 67.4 years). The most frequent symptoms were hematuria that was found in 31 cases (24 gross hematuria and 7 microscopic hematuria). Histopathologically, there were 30 transitional cell carcinomas (TCC), 1 squamous cell carcinoma (SCC), 2 TCC > SCC and 1 papillary adenocarcinoma. As to staging, 1 was pTis, 5pTa, 11pT1, 3pT2, 11pT3 and 4pT4. As to grading, 9 were G1, 16 G2 and 9 G3. The incidence of cancerous vessel invasion was noted in 8 of the 29 patients. The 5-year survival rate (Kaplan-Meier's method) was 44.9% for all of the patients. The 5-year survival rate according to staging and according to grading were as follows: 76.7% for low stage (pTis, pTa, pT1, pT2), 24.9% for high stage (pT3, pT4), and 83.3% for G1, 59.9% for G2 and 0% for G3. The 5-year survival rate was 20.8% and 68.7% in the patients with and without vessel invasion, respectively. Grade, stage and cancerous vessel invasion was suggested to be associated with the prognosis in renal pelvic and ureteral tumors.

Adenocarcinoma, Papillary↗
PubMed1994

Induction of metallothionein synthesis by bismuth in cultured vascular endothelial cells.

Metallothionein synthesis induced by bismuth nitrate was characterized using a cell culture system. It was found that bismuth (1-10 microM) significantly increased the intracellular accumulation of metallothionein in bovine aortic endothelial cells without an exhibition of cytotoxicity and a change of either general protein synthesis or proliferative DNA synthesis after a 24-h incubation. A low increase in the metallothionein accumulation was observed in bovine aortic smooth muscle cells; however, porcine kidney epithelial LLC-PK1 cells, human Chang liver cells and two human hepatoma cell lines (HLF cells and Hep-G2 cells) did not respond to bismuth. Other cations including cobalt, lead and zinc at 10 microM failed to induce metallothionein in endothelial cells, although cadmium at 1 microM was a strong inducer. Bismuth accumulated highly in endothelial cells but very slightly in LLC-PK1 cells and Chang liver cells. The present data suggest that bismuth is a selective inducer of metallothionein of vascular endothelial cells and this cell type particularly responds to the cation.

Adenine↗
PubMed1994

Radiotherapy for hepatocellular carcinoma: clinicopathological study of seven autopsy cases.

The clinical value of radiotherapy for hepatocellular carcinoma (total tumor dose: 50-70 Gy) was evaluated in seven autopsied patients with nine tumors. A partial response as defined by the WHO criteria for chemotherapy was observed in three tumors (33%). Progressive and marked shrinkage of the noncancerous liver tissue within the irradiated field was also observed in all cases. Histological examination revealed viable cancer cells in all cases. These results indicate that local radiotherapy applying 50-70 Gy achieved some clinical benefit, but was not capable of curing hepatocellular carcinoma.

Aged↗
PubMed1994

Patient registration and treatment allocation in multicenter clinical trials using a FAX-OCR system.

This article describes the design and results of implementation of an automated patient registration and treatment allocation system (RETAS) used in multicenter clinical trials. RETAS was developed using a FAX-OCR system by which handwritten Japanese and English characters, as well as numericals and forms with check boxes, are sent from participating institutions by Fax, processed using an optical character reader, and then transmitted to a host computer at a statistical center. Based on the facsimile data, RETAS can automatically review eligibility, collect patient identification data and provide a randomized treatment allocation. RETAS permits uninterrupted, unattended operation at a statistical center, 24 hours a day, 7 days a week. Therefore, it drastically decreases the workload of personnel at the statistical center needed to support central telephone registration coverage. Consequently, staff members are free to focus on patient registration, treatment allocation, and follow-up of patients. The treatment allocation procedure in this system is based on Pocock and Simon's minimization method combined with Zelen's method for institution balancing. By this system it was possible to balance treatment numbers for each level of various prognostic factors over an entire trial and, at the same time, balance the allocation of treatments within an institution. The system currently supports the protocol of a clinical trial for Adjuvant Chemo-Endocrine Therapy for Breast Cancer in West Japan.

Computer Systems↗
PubMed1994

[A prospective study of steroid-induced osteonecrosis by MRI screening].

The first aim of this study was to investigate the efficacy of magnetic resonance imaging (MRI) for detecting multiple osteonecrosis, and the second aim was to determine the onset and early development of the osteonecrotic lesions by the MRI. MRI was employed to examine for osteonecrosis in the hip, knee, ankle and shoulder in 140 patients who received high-dosage corticosteroids (over 30 mg of prednisolone per day) for their condition. Osteonecrosis was indicated by the presence of band-like lesions on the MRI. In 33 hips of 20 patients, hip prostheses had already been performed because of osteonecrosis in the femoral head. One hundred and twenty (86%) of the 140 patients had affected joints. MRI showed osteonecrotic lesions in 176 hips of 99 patients, in 143 knees of 77 patients, in 46 ankles of 30 patients and in 44 shoulders of 25 patients. Osteonecrosis in the knee occurred very frequently, so MRI was useful to examine the knee to detect multiple osteonecrosis. When there was no osteonecrosis in either the hip or the knee, then osteonecrosis in the ankle or shoulder was rare. We concluded that MRI screening of both the hip and knee was sufficient to detect multiple osteonecrosis. A prospective study of osteonecrosis was carried out. A total of 35 patients who had undergone a first MRI examination within 6 months from high-dosage corticosteroid administration were followed up by MRI. Characteristic MRI findings of osteonecrosis were present in 13 patients (37%) involving 11 hips (16%) and 18 knees (26%). In the remaining 22 patients, MRI showed no abnormal findings. The appearance of band-like lesions on MRI occurred at approximately 3 months from the corticosteroid administration. In 4 hips of 2 patients and in 12 knees of 7 patients, the observed band-like lesions gradually diminished until approximately 1 year from the administration, but since then the band-like lesions showed no further reduction on MRI.

Adolescent↗
PubMed1994

[Changes in plasma interleukin 6 in a surgical case of left atrial myxoma].

It was recently described that the cardiac myxoma produced Interleukin-6 (IL-6) as a kind of cytokines, and the constitutional signs in patients with cardiac myxoma were due to the IL-6 production. We measured the values of plasma IL-6 concentration before and after surgical therapy. It was decreased from 7.2 pg/ml to less than 4.0 pg/ml two months after surgical removal of the myxoma. It is recommended that the measurement of IL-6 is useful for screening of cardiac myxoma and postoperative follow-up.

Biomarkers, Tumor↗