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Biomedical subjects

M Hashimoto

Publications and source records attributed to M Hashimoto.

At least 325 records · Page 18Linked to original sources
PubMed1999

Differences in heart rate variability between young and elderly normal men during graded head up tilt.

An autoregressive spectral analysis of heart rate variability (HRV) was used to analyze the differences in autonomic functions during graded head up tilt (HUT) between young and elderly men. After recording at the 0 degree position, the table was rotated to an upright position. The incline of the table was increased progressively to 15 degrees, 30 degrees and 60 degrees. The data obtained from seven young subjects (mean age of 20.0 years) and nine elderly subjects (mean age of 63.3 years) were analyzed. The high frequency components expressed by normalized units (HFnu) were used as the parasympathetic indicators, and HFnu decreased with tilt angle in both age groups. These results suggested that parasympathetic withdrawal have an important role in adaptation to an upright posture in both age groups. However, mean HF amplitude at the 0 degree position in elderly men was not significantly different from that of young men at 60 degrees tilt. A significant interaction effect (age group x tilt angle) was found for mean HF amplitude. The increase of the low frequency components expressed by normalized units (LFnu) and the LF-to-HF ratio in elderly subjects from 0 degree to 15 degrees seemed to be larger than that in young subjects. Sympathetic activities may be sensitive to lower levels of orthostatic stress in the elderly, and the elderly workers are easily affected by a change in workload. Therefore, keeping the workload lower and constant may be recommended to avoid excessive sympathetic activation among the elderly.

Adolescent↗
PubMed1999

A case of intraabdominal bleeding following pancreatoduodenectomy successfully treated by transcatheter arterial embolization.

A 58-year-old male underwent pancreatoduodenectomy based on a diagnosis of middle bile duct cancer. Because abdominal drainage revealed bile leakage 5 days postoperatively, leakage at the site of cholangiojejunostomy was diagnosed, and continuous aspiration was performed. Seventeen days postoperatively, pus was discharged through the abdominal drain. Because bleeding was detected by abdominal drainage, and shock ensued 20 days postoperatively, emergency abdominal angiography was carried out to identify the bleeding site. A false aneurysm in the proper hepatic artery and extravasation from the gastroduodenal artery stump were recognized, and therefore, the proper hepatic artery and common hepatic artery were embolized at a site distal to the false aneurysm using microcoils. Celiac arteriography after transcatheter arterial embolization (TAE) did not show extravasation, and revealed blood flow from the right inferior phrenic artery to the liver. Liver function was normal after TAE, and the patient recovered and was discharged from the hospital 54 days postoperatively. This paper presents a patient in whom intraabdominal bleeding due to leakage at the site of cholangiojejunostomy complicated by infection was successfully treated by hemostasis with TAE.

Abdomen↗
PubMed1999

A long-term survival patient with advanced gallbladder cancer massively metastasizing to the liver.

A case of gallbladder carcinoma was reported. A 42-year-old woman was admitted with epigastralgia. Abdominal ultrasonography, computed tomography, and other diagnostic modalities suggested gallbladder carcinoma with multiple liver metastases. These findings indicated no surgical procedure because of the advanced nature of her disease. After the hepatic arterial chemoinfusion therapy, her multiple liver metastatic lesions showed a decrease in size and number. Therefore, extended left lobectomy of the liver with gallbladder and bile duct resection were performed. Five years after initial operation, a solitary liver metastatic lesion (S5) was diagnosed by ultrasonography. Partial resection of the liver was performed for the liver metastasis, and her postoperative recovery was uneventful and had a good follow-up course. One year after the second operation bone metastases occurred, therefore, peroral administration of UFT (Tegafur + Uracil) and radiation therapy for the metastatic lesions of sternum and lumbar vertebra (L1) were performed.

Adult↗
PubMed1999

Internal mammary artery embolization for hemoptysis.

PURPOSE: The purpose of this study was to determine the factors influencing development of blood supply from the internal mammary artery and to discuss the value of embolization of the abnormal branches from this vessel using small particles following occlusion of the normal distal branches using microcoils in treating hemoptysis. MATERIAL AND METHODS: Five patients with hemoptysis underwent internal mammary artery embolization with coaxial microcatheter systems. Bronchoscopy, chest radiographs, and CT were performed to determine the site and extent of the basic disease before embolotherapy in all patients. RESULTS: In all patients, pulmonary lesions had extended from the lung to the adjacent pleural surface at the anterior lung field. Four patients underwent embolization from the proximal portion of the internal mammary artery following distal coil embolization. One patient who underwent only proximal embolization had recurrent bleeding. CONCLUSION: The internal mammary artery contributes to the perfusion of lesions responsible for hemoptysis when the basic lesion involves the pulmonary parenchyma adjacent to the anterior pleural surface. Initial distal occlusion of the internal mammary artery may improve the efficacy of embolization of this artery for hemoptysis.

Aged↗
PubMed1999

[Continuous total intravenous anesthesia is useful for postoperative pain management].

We compared postoperative pain in two groups. All anesthetic agents were continuously administered intravenously in a continuous PKF (propofol 2-10 mg.kg-1.h-1, ketamine 240 micrograms.kg-1.h-1 and fentanyl 0.4 microgram.kg-1.h-1) group. In a control group, anesthesia was maintained by GOI (N2O-oxygen-isoflurane). Twenty-two patients scheduled for gynecological lower abdominal surgeries were divided into the continuous PKF group (n = 11) and the GOI group (n = 11). Epidural anesthesia was employed in both groups, using local anesthetic agents and fentanyl during surgeries and for 24 hrs postoperatively. To evaluate pain, VAS and Prince Henry Score on rest, cough and movement were taken 2 hrs and 5 hrs postoperatively, and in the morning and afternoon of the 1st as well as 2nd postoperative days. The continuous PKF group showed lower scores than the GOI group. It is a great advantage to use continuous PKF for postoperative pain management, and our data indicate that low dose ketamine may induce pre-emptive analgesia.

Abdominal Pain↗
PubMed1999

[Effect of macro-creatine kinase in serum on dry chemistry methods results for total creatine kinase activity].

Most enzymes in serum that are measured in clinical laboratories can occur in macro-molecular forms in a significantly number of patients. Within dry chemistry (DC) multilayer film, physical barriers may prevent contact macro-molecular enzyme forms with the active reagent ingredients. Here, serum samples with macro-creatine kinase (macro-CK) type 1: CK-immunoglobulin complex or type 2: oligomer mitochondrial CK (CKm) were analyzed for total CK activity on three different DC analyzers: VITROS 700XR, FUJIDRYCHEM 5000, SPOTCHEM SP4410 and a classic wet chemistry (WC) analyzer: HITACHI 7350. Macro-CKs were detected and identified by electrophoresis on cellulose acetate. Serum with high amounts of oligomer CKm gave CK values by all of DC methods significantly lower than that by the WC method (p < 0.05). Oligomer CKm gradually converts into monomer forms in serum after storage. With increase in day after storage at 4 degrees C, there was a gradual shift in which percent of total CK activity for oligomer CKm decreased while the ratio of total CK activity, DC method/WC method increased. The principle of analytical method for CK activity determination is commonly to all of the DC methods, the WC method and the electrophoretic analysis. These suggest that oligomer CKm is sieved by DC multilayer film elements. In contrast, each of DC method produced highly corrected CK activities for sample containing CK-immunoglobulin complex. This difference in the effects of macro-CKs may depend upon physicochemical characteristics of analytical DC elements.

Blood Chemical Analysis↗
PubMed1999

[Assessment of a new non-invasive cerebral blood flow determination method using the brain uptake ratio of 99mTc-ECD].

We modified the method of calculating brain uptake ratio (BUR) reported previously, and devised a new non-invasive cerebral blood flow measurements for 99mTc-ECD that does not require blood sampling. This method yields BUR that is not influenced by the gamma camera type and the choice of acquisition-reconstruction conditions, when corrected by the SPECT/Planar cross calibration coefficient. A good correlation was observed between the BUR obtained by this method and the cerebral blood flow (CBF) obtained by the 123I-IMP continuous arterial blood sampling method. And based on these results, it is now possible to convert BUR to CBF. This method is applicable to small field type of gamma cameras, and it is expected to be useful as a routine test.

Brain↗
PubMed1999

Diurnal variation of autonomic nervous activity in the rat: investigation by power spectral analysis of heart rate variability.

We studied the diurnal variations of autonomic nervous function in rats. For this purpose, a long-term electrocardiogram (ECG) was recorded from conscious and unrestrained rats using a telemetry system, and the autonomic nervous function was investigated by the power spectral analysis of heart rate variability. No arrhythmias were observed in the ECG of any of the rats. Nocturnal patterns, in which the values of heart rate in the dark phase (2000-0600) were higher than those in the light phase (0600-2000), were observed. All normal rats shared a characteristic pattern in their power spectrum analysis. Both low-frequency and high-frequency power in the light phase were higher than those in the dark phase. However, these differences were not statistically significant (P > .05). The low frequency to high frequency ratio also showed a nocturnal pattern. The value in the dark phase was significantly higher (P < .05) than that in the light phase. These results suggest that the sympathetic nervous activity is predominant in the dark phase in rats. Therefore, we believe that this information may be useful for future biobehavioral studies.

Animals↗
PubMed1999

[Latent factors aggravating airway allergic symptom in urban population: the involvement of urban living environments].

The involvement of urban living environments in IgE-increase (atopy) and ECP-increase (enhanced eosinophil activity), the inter-relationship of IgE-increase and ECP-increase, and their involvement in developing airway allergic symptoms were studied on a population of adult nonsmoking women, in order to elucidate the latent factors aggravating airway allergic symptoms in an urban population. In our earlier study on child asthma in 1994, we examined the relationship between living environments and mite proliferation in asthma and non-asthma groups and the involvement of mite proliferation in developing atopy in the non-asthma group. The asthma group consisted of 190 children under 12 years old who had been recently diagnosed as having bronchial asthma and under the care of Osaka Prefectural Habikino Hospital. The non-asthma group consisted of 78 children under 12 years old who had been under care at Osaka Prefectural Hospital but had no present history of allergic symptom. The adult woman group consisted of 423 non-smoking women who had been diagnosed as having no allergic disease by the medical examination done at Yao City, Osaka, each March from 1995 to 1997. Individual living environments such as housing and heating styles were surveyed by questionnaire. Also, the amount of mite allergen (Dp: Dermatophagoides pteronyssinus, Df: Dermatophagoides farinae) in room and bedding dust (only in the case of children) and the concentration of continine in urine were examined as objective indicators for the load of environmental allergen and the indoor air pollution by tobacco smoke, respectively. Atopy was diagnosed according to whether Dp-specific immunoglobulin E (Dp-IgE) was present/absent (positive/negative), and ECP-increase was defined as serum ECP concentration over 10 ng/ml. The results were as follows: 1. An environment of higher humidity (dampness) causing a room to become moldy appeared to enhance mite proliferation, while heating only with an electric heater or kotatsu appeared to suppress it. 2. Living environments were involved in the development of atopy in children and adult women through the effects on mite proliferation. In the case of children, heating with oil or gas heater appeared to have a positive effect while reinforced concrete housing a negative effect, probably by effects on the immune system. However, in the case of adult women, such modification was not observed. 3. Passive smoking in adult women was related to ECP-increase. 4. IgE-increase and ECP-increase appeared to be involved in each other. 5. Among airway allergic symptoms such as cough, sputum and wheeze, atopy was involved in wheeze, and ECP-increase in cough.

Adult↗
PubMed1999

[A case of recurrent colon cancer with complete response to modulation chemotherapy using low-dose leucovorin and 5-fluorouracil].

We experienced a case of lymph node recurrence from colon cancer with complete response to modulation chemotherapy using low-dose leucovorin and 5-FU. The patient was a 68-year-old male. He underwent sigmoid colon resection for sigmoid colon cancer in October 1993. In June 1994, he complained of left lower abdominal pain. Swelling of retroperitoneal lymph node was detected by CT scan and cytology revealed cancer cells in urine. He was diagnosed as having lymph node recurrence. He then was given modulation chemotherapy of 30 mg of leucovorin and 500 mg of 5-FU that were bolus injected intravenously for 5 days. After 2 cycles of this regimen, the recurrent mass disappeared completely for further examination. Until May 1998, he had received 14 cycles. Since this regimen started, his survival period has been 46 months, and his response duration 42 months.

Aged↗
PubMed1999

[Cytopathology of the breast--benign and malignant neoplastic conditions].

Breast cancer is one of the most common malignancies in women and the incidence has been increasing. Cytology plays a very important role not only in the diagnosis of breast lesions, but also in keeping the benign-to-malignant biopsy ratio low, so that unnecessary surgery is not performed. A fundamental feature of a benign aspirate is the presence of a dual population of ductal epithelial cells (variable within limits, but cohesive and orderly) and myoepithelial cells (naked, bipolar nuclei). Several cytologic features must be assessed to make the diagnosis of malignancy, including high cellularity, cell dissociation, large nuclear and cell size, cell pleomorphism, intracytoplasmic lumens (containing mucin), irregular nuclear margin, coarse chromatinic pattern, prominent nucleoli, and the presence of abnormal mitoses. Other criteria of lesser importance include necrosis, absence of myoepithelial cells and intranuclear inclusions. However, breast carcinomas do not always show every feature of malignancy. The well-differentiated or low-grade carcinomas are often difficult to differentiate from benign cells. It may be helpful to consider the clinical and radiological findings. We reported here, typical neoplastic lesions of the breast by correlating cytological with histopathological features.

Biopsy↗
PubMed1999

[Detection of hematopoietic stem cells by flow cytometry, hematology analyzer or in vitro culture method].

We describe 3 different ways to determine the number of hematopoietic stem or progenitor cells in peripheral blood and harvest juice for peripheral blood stem cell transplantation. Flow cytometric analysis of CD34 positive cells gives us relatively quick and reliable results, although it's quite expensive. Automated hematology analyzer, SE-9000, exhibits real time appearance of stem cell population in a least expensive way. Colony formation in vitro such as CFU-GM is a direct way to detect hematopoietic committed cells, however this is time-consuming. We have to choose proper ways for each institute.

Blood Cell Count↗
PubMed1999

Functional capacity of the cirrhotic liver after partial hepatectomy in the rat.

BACKGROUND: Posthepatectomy liver insufficiency is one of the most serious problems associated with a major hepatic resection, especially in the cirrhotic liver, which has less functional reserve than the normal liver. Evaluation of morphologic liver regeneration is important in cirrhotic rats, as well as in the normal liver, and assessment of functional capacity in cirrhosis is clinically important for preventing hepatic insufficiency of the remnant liver after hepatectomy. METHODS: We evaluated the functional capacity of the cirrhotic liver induced by carbon tetrachloride in rats and studied the correlation between morphologic and functional restoration of the liver after partial hepatectomy in comparison with healthy rats. Morphologic restoration of the liver after hepatectomy was evaluated on the basis of remnant liver weight, proliferating cell nuclear antigen labeling index, and the DNA content of the regenerating liver. Functional restoration was evaluated by the indocyanine green disappearance rate and serum aminopyrine clearance. RESULTS: Morphologic restoration in cirrhotic rats was delayed in comparison with healthy rats. Although functional capacity in the cirrhotic rats was diminished, functional restoration was advanced after a two-thirds hepatectomy, in comparison with morphologic restoration. CONCLUSIONS: Functional restoration in cirrhotic rats after partial hepatectomy is advanced in comparison with morphologic restoration.

Animals↗
PubMed1999

Successful tracheocarinal transplantation.

BACKGROUND: When extensive portions of the trachea and carina are resected, grafting is required. METHODS: Two experiments were performed in dogs to assess the feasibility of extensive tracheocarinal replacement using short-segment tracheocarinal autografts, only to avoid the immunologic complexity of allografts. To determine the effect of tension on graft survival, extensive tracheal defects (12 to 18 rings) were created in four animals. These were subsequently reconstructed using 6-ring autografts. In the second experiment, three animals underwent excision of a maximal length of trachea determined in experiment 1 including the carina. Long-term viability of each graft was assessed using bronchoscopy and histologic examination. RESULTS: The limit of tracheal resection successfully reconstructed using a 6-ring autograft was 14 rings (experiment 1). The tracheal grafts in which the tension was greater than 1.2 kg did not maintain their structural integrity. All of the autografts in experiment 2 were subjected to a tension of less than 1.0 kg at the anastomoses, and showed long-term viability. CONCLUSIONS: We conclude that extensive tracheal and carinal defects may be successfully reconstructed using short-segment tracheocarinal grafts if the anastomoses are subjected to less than 1.0 kg of tension.

Airway Resistance↗
PubMed1999

A2E, a lipofuscin fluorophore, in human retinal pigmented epithelial cells in culture.

PURPOSE: To study A2E, a component of retinal pigmented epithelial (RPE) cell lipofuscin, after its internalization by cultured human RPE cells. METHODS: A2E was synthesized and incubated with an adult RPE cell line devoid of native lipofuscin. To investigate the cellular compartmentalization of A2E, cells were incubated simultaneously with A2E and a fluorescent acidotropic probe, (Lysotracker Red DND-99; Molecular Probes, Eugene, OR). Plasma membrane integrity was evaluated by assaying for leakage of the cytoplasmic enzyme lactate dehydrogenase (LDH), by fluorescence nuclear staining with a membrane-impermeant dye and by morphologic criteria. The emission spectrum of internalized A2E was also determined. The levels of A2E accumulated by the cultured cells were quantified by high-performance liquid chromatography and compared with amounts present in RPE isolated from human eyes. RESULTS: Internalization of A2E by the RPE cells was evidenced by the acquisition of intracellular granules detectable by fluorescence confocal imaging. Internalized A2E had an emission maxima of 565 to 570 nm. The levels of A2E accumulating in cells incubated with 10 to 25 microM A2E were comparable to the amounts of A2E present in equal numbers of RPE cells harvested from human eyes. Colocalization of A2E and the Lysotracker probe revealed a preferential accumulation in acidic organelles. The elevated LDH levels that were measured after exposure to 50 and 100 microM A2E were attributable to membrane damage in a subpopulation of the A2E-accumulating cells, determined by fluorescence nuclear labeling. CONCLUSIONS: Internalized A2E has an affinity for acidic organelles. The membrane damage exhibited by A2E-accumulating RPE is dependent on the concentration of A2E and reflects the ability of this amphiphilic compound to exert detergent-like effects.

Aged↗
PubMed1998

Isolation and one-step preparation of A2E and iso-A2E, fluorophores from human retinal pigment epithelium.

Age-related macular degeneration, a major cause of blindness for which no satisfactory treatments exist, leads to a gradual decrease in central high acuity vision. The accumulation of fluorescent materials, called lipofuscin, in retinal pigment epithelial cells of the aging retina is most pronounced in the macula. One of the fluorophores of retinal pigment epithelial lipofuscin has been characterized as A2E, a pyridinium bis-retinoid, which is derived from two molecules of vitamin A aldehyde and one molecule of ethanolamine. An investigation aimed at optimizing the in vitro synthesis of A2E has resulted in the one-step biomimetic preparation of this pigment in 49% yield, readily producing more than 50 mg in one step. These results have allowed for the optimization of HPLC conditions so that nanogram quantities of A2E can be detected from extracts of tissue samples. By using 5% of the extract from individual aged human eyes, this protocol has led to the quantification of A2E and the characterization of iso-A2E, a new A2E double bond isomer; all-trans-retinol and 13-cis-retinol also have been identified in these HPLC chromatograms. Exposure of either A2E or iso-A2E to light gives rise to 4:1 A2E:iso-A2E equilibrium mixtures, similar to the composition of these two pigments in eye extracts. A2E and iso-A2E may exhibit surfactant properties arising from their unique wedge-shaped structures.

Humans↗