Biomedical subjects

I Murakami

Publications and source records attributed to I Murakami.

At least 73 records · Page 4Linked to original sources

PubMed1995

The theory of the curvature-constraint line for amodal completion.

Amodal completion of partly occluded figures is analyzed as natural computation. Here amodal completion is shown to consist of four subproblems: representation, parsing, correspondence, and interpolation. Second, each problem is shown to be basically solvable on the basis of the generic-viewpoint assumption. It is also argued that the interpolation problem might be the key problem because of mutual interdependence among the subproblems. Third, a theory is described for the interpolation problem, in which the generic-viewpoint assumption and the curvature-consistency assumption are presumed. The generic-viewpoint assumption entails that the orientation and the curvature should not change at the point of occlusion. The curvature-consistency assumption entails that the hidden contour should have the minimum number of inflections to maintain continuity in orientation and curvature. The shape of the interpolated contour represented qualitatively in terms of the number of inflections can uniquely be determined when the location of the terminators and local orientation and curvature of the visible contours at the terminators are given. Fourth, it is shown in an instant psychophysics that the theory is highly consistent with human performance.

Adult↗

PubMed1995

[Relationship between impaired blood pressure control and multiple system involvement in chronic alcoholics].

Chronic ethyl alcohol (ethanol) abuse is associated with different types of neurological involvement. Impaired blood pressure control such as in hypertension and/or orthostatic hypotension is a known autonomic dysfunction in chronic alcoholics. Although abstinence appears to improve blood pressure, the precise mechanisms underlying the effects of alcohol remain unknown. We suspected that abnormal blood pressure might influence the outcome of alcohol-related neurological symptoms. We therefore reviewed the alcohol history of 28 male patients admitted to our hospital with multiple system involvement. No family history of spinocerebellar degeneration was found. All of the patients had a history of chronic alcohol abuse. The duration of alcohol abuse in 28 patients was 28.8 + 11.2 yrs. Daily ethanol consumption was less than 83 ml in 6 patients between 83 ml and 138 ml in 11 and more than 138 ml in 11. We assessed the relationship between impaired blood pressure control, clinical characteristics, and outcome after abstinence for a period ranging from 30 days to 6 years in 22 chronic alcoholics who had drunk more than 83 ml/day. All of the patients had various types of autonomic dysfunction, and a high incidence of impaired blood pressure control and decreased CVR-R were noted. The symptoms improved or even completely resolved after cessation of alcohol consumption, however, 8 of the 22 patients in our study reached a plateau and have permanent symptoms. Patients with no improvement as a result of abstinence had a long history of excessive drinking. Brain CT/MRI, SPECT and P300 studies were conducted. SPECT and P300 were performed in both the supine and standing position in 5 and 7 patients, respectively. Five patients who had severe orthostatic hypotension with syncope were found to have cerebrovascular lesions on MRI. Changes in P300 amplitude and/or distribution and latency were noted after a fall in blood pressure. Although the etiology of impaired blood pressure control in alcoholics remains unknown, we believe that abnormal blood pressure affects the outcome of alcohol-related neurological symptoms.

Adult↗

PubMed1995

Bauhinia purpurea and Pisum sativum lectin binding in human breast.

The binding of biotinylated bauhinia purpurea (BPA) and pisum Sativum (PSA) lectins to paraffin-embedded tissue sections from 10 normal breast and 55 breast carcinoma has been investigated by applying avidin biotin peroxidase method (ABC). BPA showed very low affinity for normal breast epithelium and the binding was confined to the luminal surface. Eighty-seven percent carcinoma bound BPA, and the staining patterns varied depending on the histologic grade of tumors: luminal surface binding in grade 1 carcinomas; diffuse, granular cytoplasmic with para- or perinuclear deposits and staining along the plasma membrane in grade 2 and grade 3 carcinomas. PSA bound consistently to the luminal surface of all ducts and acinar cells of normal breast tissue. PSA was reactive with all carcinoma but the staining profiles were similar regardless of the tumor differentiation. It is concluded that the lectins used in this study have limited usefulness in routine diagnosis.

Breast↗

PubMed1994

Gas gangrene following sacral pressure sores.

We report two cases of gas gangrene developed from sacral pressure sores. The first case was clostridial and the second, non-clostridial gas gangrene. Both patients died within two months. The first patient, a 56-year-old woman suffering from palsy of the lower half of the body for 3 weeks, developed a sacral pressure sore. One month later, crepitus by palpation and gas formation in the X-ray film were detected in the hip and right thigh. A culture of odoriferous pus yielded Clostridium limosum in addition to Staphylococcus intermedius, Enterococcus faecalis, Pseudomonas aeruginosa, and Bacteroides fragilis. Blood culture yielded Bacteroides fragilis. The patient died 50 days after admission in spite of surgical debridement and aggressive therapy with high doses of antibiotics and hyperbaric oxygen. The second patient, a 70-year-old man suffering from diabetic nephropathy, arteriosclerosis obliterans of the lower limbs, and cerebral infarction, developed a large decubitus ulcer covering the whole sacral area. Crepitus and gas were detected in the soft tissue of the left gluteal region. Almost the entire gluteus maximus muscle was necrotic. Bacteroides fragilis, methicillin-resistant or -sensitive Staphylococcus aureus and Escherichia coli were isolated from the muscle. Bacteroides fragilis was also obtained by blood culture. The patient died on the 72nd day after admission.

Aged↗

PubMed1994

Malignant peripheral nerve sheath tumor with prominent intracytoplasmic vacuolation: report of a case.

A case of malignant peripheral nerve sheath tumor with uncommon features is reported. A mass was noted in the left thigh of a 16 year old man. Histologically, most areas of the tumor exhibited the typical appearance of malignant peripheral nerve sheath tumor, but some tumor cells had rounded nuclei and cytoplasm, resembling an epithelioid pattern. It was noted that some rounded tumor cells showed prominent intracytoplasmic vacuolation. Immunohistochemically, almost all of the tumor cells, including the rounded and vacuolated ones, were positive for S-100 protein and vimentin. Electron microscopic study revealed well-developed cytoplasmic processes, intracytoplasmic intermediate-sized filaments, basement lamina formation and extracellular long-spacing collagens. These findings were compatible with those of Schwann cell differentiation. Moreover, ultrastructurally, the vacuolated spaces contained a few granular materials and were derived from the dilatation of the rough endoplasmic reticulum. It is speculated that intracytoplasmic vacuolation in malignant peripheral nerve sheath tumor would be caused by degeneration of the tumor cells.

Adolescent↗

PubMed1994

[A suspected case of T0N1M0 small cell carcinoma of the lung].

A 51-year-old man was admitted to our hospital with a chief complaint of cough. His chest X-ray and CT scan revealed enlargement of a left hilar lymph node. However, no primary lesion was apparent in the rest of the lung. Bronchofiberscopic findings were essentially normal. At surgery the mass was determined to be an enlarged lymph node (No. 11). No apparent malignant lesion was identified in the lung. Postoperative pathological examination showed small cell carcinoma in a part of the No. 11 lymph node. Despite a thorough systemic examination, no primary foci were detected. We have been following up this patient with chemotherapy for the approximately 2 year period since the operation, but no primary lesions have been detected as yet. Therefore, we speculate that this patient is a very rare case of primary unknown T0N1M0 lung cancer.

Carcinoma, Small Cell↗

PubMed1994

Bauhinia purpurea agglutinin (BPA) binding sites in human gastrointestinal tract.

The binding of biotinylated BPA to parraffin sections of 18 normal gastrointestinal tract mucosa, 5 nonneoplastic polyps (NNP), 12 adenomas, and 59 carcinomas was studied by using avidinbiotin peroxidase complex (ABC) technique. In normal mucosa BPA appeared to bind both mucus and nonmucus glycoproteins but goblet cell mucus showed a decrease in binding and increase in binding of nonmucus glycoproteins as the cells lose their differentiation. BPA showed characteristic binding patterns in adenoma and carcinoma that differed from the pattern in normal mucosa. In normal mucosa linear binding to the apical cytoplasm in the columnar cells of the surface epithelium was observed, whereas in adenomas and carcinomas, in addition to the linear binding to the apical cytoplasm, diffuse cytoplasmic and granular deposits in the supranuclear, paranuclear or infranuclear zones were seen. Our findings suggest that BPA binding patterns in normal and neoplastic mucosa are related to the degree of cellular differentiation. In the process of malignant transformation the carbohydrate distribution undergoes progressive changes through the adenoma carcinoma sequence. These changes are related to the degree of dysplasia in adenomas and to the degree of differentiation in carcinomas.

Adenocarcinoma↗

PubMed1994

Lectin histochemistry of normal lung and pulmonary carcinoma.

Normal bronchopulmonary tissues and pulmonary carcinomas including three major types (squamous cell carcinoma, adenocarcinoma, and small-cell carcinoma) were studied using three biotinylated lectins (Bauhinia purpurea [BPA], Phaseolus vulgaris [PHA], and Maclura pomifera [MPA]) by avidin biotin peroxidase complex (ABC) method. The study demonstrated that BPA binds with macrophages and pneumocytes of normal tissue, and with adenocarcinoma and small-cell carcinoma, but nonreactive with squamous cell carcinoma. PHA and MPA bound to all the normal components of bronchopulmonary tree and carcinomas of all types. Adenocarcinoma showed the highest density of reacting sites for BPA and MPA, and squamous cell carcinoma showed the highest binding sites for PHA, while small-cell carcinoma were the lowest reacting variant for all lectins. Lectins used in this study have limited usefulness for the diagnosis of pulmonary neoplasms.

Adenocarcinoma↗

PubMed1993

Motion capture changes to induced motion at higher luminance contrasts, smaller eccentricities, and larger inducer sizes.

In the stimulus configuration for "motion capture" phenomenon, we varied luminance contrast of the center disk (target), eccentricity and stimulus size. The subjects had to judge the direction of perceived target motion. We found that motion capture changed to induced motion (the direction of illusory motion was reversed) at smaller eccentricities and larger stimulus sizes. At intermediate eccentricities, motion capture changed to induced motion with increasing luminance contrast of the target. By using magnitude estimation, we also found that even a luminance-defined target was captured ("homochromatic motion capture") and that a moving target was captured by a stationary inducer ("position capture"). Both motion and position capture effects were commonly observed at lower luminance contrasts of the target, larger eccentricities and smaller sizes. From these results, we propose a model of center-surround antagonistic motion contrast detectors in motion processing.

Contrast Sensitivity↗

PubMed1993

Spindle cell hemangioendothelioma: a report of two cases.

Two cases of spindle cell hemangioendothelioma (SCH) are reported. One of the patients was a 16 year old Japanese female, who had been suffering from Ollier's disease (multiple enchondromatosis) since 3 years of age and had developed multiple SCH in the right leg at the age of 11 years. Spindle cell hemangioendothelioma lesions coincided with the site of enchondromatosis and increased in number thereafter. This is the first report of Ollier's disease complicated with multiple SCH. Another patient, a 33 year old Japanese female, who was a carrier of hepatitis B virus (HBV), developed solitary SCH in the lateral aspect of the right ankle where a lipoma was extirpated 10 years previously. Tumor cells of both cases were composed of four cell types: (i) spindle cells; (ii) epithelioid cells; (iii) vacuolated endothelial cells; and (iv) usual endothelial cells. Endothelia in the cavernous area and vacuolated cells reacted to Ulex europaeus agglutin 1 (UEA-I), factor VIII-related antigen and vimentin. Spindle cells and epithelioid cells reacted only to vimentin.

Adolescent↗

PubMed1993

Bauhinia purpurea lectin (BPA) binding spectra in hyperplastic human tonsil and in peripheral blood: immunohistochemical, immunoelectron microscopic, and flow cytometric analyses.

We studied the binding of Bauhinia purpurea lectin (BPA) to human tonsils and peripheral blood mononuclear cells by immunohistochemical, immunoelectron microscopic, and flow cytometric techniques. The effect of several fixatives (acetone, ethanol, buffered and non-buffered formalin, B5, Bodian 11, Bouin's, Carnoy's, Zenker's, and glutaraldehyde) was also examined. BPA was reactive with germinal center lymphocytes, macrophages/histiocytes, follicular dendritic cells, squamous epithelial cells, and a subset of endothelial cells. Mantle zone and paracortical lymphocytes were non-reactive with BPA. The profile of the specific binding characteristic of BPA lectin was found to be influenced by the fixatives. Most significantly, formalin fixation greatly reduced overall binding intensity, particularly making germinal center lymphocytes totally non-reactive. The reaction intensity was most prominent in frozen sections or those fixed in Carnoy's or ethanol solution. The combination of heavy metal salt-containing fixatives with acetic acid usually did not enhance BPA binding. Glutaraldehyde solution used for immunoelectron microscopic study also preserved BPA receptors fairly well, and BPA was confined to the membrane in lymphocytes and to both the membrane and cytoplasm in macrophages/histiocytes and follicular dendritic cells. Neuraminidase treatment of tissues resulted in binding of BPA to lymphocytes that were non-reactive before treatment. Double-staining studies on cell suspensions from tonsils with FITC-BPA and PE-conjugated anti-CD3 or SIg reagents revealed that 28.4% of CD3+ cells and 61.3% or SIg+ cells were BPA reactive. In PBL, 65.6% and 81.4% of CD3+ and SIg+ cells, respectively, were BPA reactive. Neuraminidase treatment also increased the percentage of BPA-reactive lymphocytes. In conclusion, BPA is a marker for macrophages/histiocytes and germinal center lymphocytes, provided that the tissues are unfixed or fixed with suitable fixatives such as ethanol or Carnoy's solution.

Adolescent↗

PubMed1993

A case of chronic pancreatitis with pseudoaneurysm rupturing into a pseudocyst.

A 44-year-old man with alcohol-induced chronic pancreatitis was referred to our institute for evaluation of severe anemia. The hemoglobin was 2.6g/dl. The results of upper gastrointestinal and colonic examination were negative. Computed tomography and ultrasound examination revealed a pseudocyst in the head of the pancreas. A pseudoaneurysm of the anterior superior pancreaticoduodenal artery shown by angiography appeared to have caused gastrointestinal bleeding by rupturing into the pancreatic cyst connected to the main pancreatic duct. A pyrorus-preserving pancreaticoduodenectomy was performed successfully.

Adult↗

PubMed1993

Masticatory improvement using osseointegrated implants: analysis of Japanese patients' responses through questionnaires.

Masticatory improvement obtained by the use of osseointegrated implants (Brånemark System) was analyzed through questionnaires collected from 22 Japanese patients. The questionnaires were designed to assess mastication of different Japanese foods. The postoperative score of masticatory function obtained by analysis of the questionnaires was 90.9, as opposed to the preoperative score of 43.9. A multiple regression analysis indicated that the number of placed implants has no significant effect on the improvement of masticatory function, whereas preoperative performance does. Further, the degree of masticatory improvement showed variation according to the condition of the dental arch opposing the implant prostheses. The group having implant prostheses in the opposing arch showed the highest improvement.

Adult↗

PubMed1992

Fasting diet therapy for chronic urticaria: report of a case.

We used fasting diet therapy with a 28-year-old woman with chronic urticaria who responded only to systemic administration of glucocorticosteroids. The rashes began to decrease on the third therapeutic day and completely disappeared on the 11th day. Although the eruptions relapsed three days after the termination of the therapy, they were milder than previous ones. We also discussed the possible efficacy of fasting diet therapy for chronic urticaria as reported in the literature.

Adult↗

PubMed1992

An immunohistochemical and ultrastructural study of case of small-cell neuroendocrine carcinoma in the ampullary region of the duodenum.

One case of small-cell neuroendocrine carcinoma in the ampullary region of the duodenum is reported. The histological appearance of the tumor was identical to pulmonary small-cell carcinoma. Neuroendocrine differentiation was demonstrated immunohistochemically by positive immunoreaction for neuron specific enolase, Leu-7 and chromogranin, and ultrastructurally by the presence of scanty dense-core neurosecretory type granules. Small-cell neuroendocrine carcinoma in the ampulla of Vater is extremely rare. To our knowledge, this is the sixth reported case.

Ampulla of Vater↗

PubMed1992

Lectin binding patterns in normal liver, chronic active hepatitis, liver cirrhosis, and hepatocellular carcinoma. An immunohistochemical and immunoelectron microscopic study.

We studied the binding patterns of 14 lectins in human normal and cirrhotic liver (LC) tissues and hepatocellular carcinomas (HCC) using the ABC method. Lectins were divided into 4 groups according to their binding patterns in normal tissues: (A) PHA, MPA, LcH, RCA-I, and WGA, which bound to hepatocytes and all three types of sinusoidal cells; (B) BPA, GS-I, PNA, and SBA, which bound to Kupffer cells and endothelia of interlobular arteries and veins and bile duct epithelia in the portal tract, but not to hepatocytes; (C) UEA-I, which bound only to endothelia of interlobular arteries and veins and bile duct epithelia in the portal tract; (D) LBA, Lotus, LPA, and SJA, which showed no binding. Thus group B lectins may be useful markers of Kupffer cells. Only electron microscopic examination revealed the precise binding sites of lectins in sinusoidal cells and hepatocytes. Hepatocyte cell surface polarities demonstrated by lectin binding in LC and HCC were different from those in the normal liver. The binding pattern of PHA to LC hepatocytes changed from a membranous to both a membranous and a cytoplasmic pattern, and that of LcH to HCC cells changed to dot-like staining in the cytoplasm. These changes of polarities in LC and HCC might be caused by changes in the distribution of lectin-binding carbohydrates or by the altered glycosylation of glycoconjugates.

Carcinoma, Hepatocellular↗

PubMed1992

Bauhinia purpurea--a new paraffin section marker for Reed-Sternberg cells of Hodgkin's disease. A comparison with Leu-M1 (CD15), LN2 (CD74), peanut agglutinin, and Ber-H2 (CD30).

Thirty-three cases of Hodgkin's disease (thirteen nodular sclerosis, four diffuse, lymphocyte predominance, and sixteen mixed cellularity) were studied with Bauhinia purpurea (BPA), peanut agglutinin (PNA), anti-Leu-M1, LN2, and Ber-H2 by the avidinbiotin-peroxidase complex (ABC) method in paraffin sections. Reed-Sternberg (RS) cells and variants were stained positively with one or more of the reagents in all cases. BPA staining was positive in 32 of 33 cases (97.0%), PNA staining was positive in 23 of 33 cases (69.7%), Leu-M1 was positive in 13 of 33 cases (39.4%), LN2 was positive in 14 of 33 cases (42.4%), and Ber-H2 was positive in 24 of 33 cases (72.7%). Many RS cells were stained moderately to strongly and were readily recognized in 31 cases (96.9%) of BPA+, 10 (43.5%) of PNA+, 8 (61.5%) of Leu-M1+, 6 (42.9%) of LN2+, and 22 (91.7%) of Ber-H2+ cases; in the remaining positive cases, the RS cells were found only after careful searching. Three staining patterns were recognized: paranuclear, diffuse cytoplasmic, and membranous. These three patterns were obtained with all markers except for LN2. LN2 showed diffuse cytoplasmic staining in most of the positive cells, and a few cells showed paranuclear deposits. BPA reactivity was not affected by formalin fixation or paraffin embedding. Except for RS cells, BPA also showed dense cytoplasmic staining reaction with macrophage-histiocytes. Sixty cases of non-Hodgkin's diffuse lymphomas (30 T- and 30 B-cell origin) were also studied. Tumor cells were not stained with BPA, PNA, and Leu-M1, but stained positively with LN2 in six T-cell lymphomas and thirteen B-cell lymphomas, and with Ber-H2 in six T-cell lymphomas and one B-cell lymphoma. In conclusion, to facilitate the detection of RS cells and related variants in paraffin sections, BPA can be accepted as a useful marker due to its high-detection rate, reproducible staining pattern, and resistance to fixatives.

Antigens, CD↗

PubMed1992

[Urinary calcium excretion as an early prediction marker for pregnancy induced hypertension].

Two hundred and forty-nine healthy women at 36 weeks gestation and 38 women with pregnancy induced hypertension (PIH) underwent urinalysis for urinary calcium excretion to obtain the calcium/creatinine ratio. This ratio was significantly lower in the women with PIH than in the healthy pregnant women, and it was especially low in those with PIH who had no family history of hypertension. Three hundred forty-eight healthy women at 20 weeks of gestation underwent urinalysis to determine their calcium/creatinine ratio as a means to predict PIH in patients showing no symptoms. In the primiparous group with no family history 58% of the patients with a low calcium/creatine ratio eventually developed PIH. Using a receiver operator curve, we calculated a predictive threshold calcium value for PIH of 0.06 at six month's pregnancy. Thus urinary calcium excretion may be a useful early marker for PIH.

Biomarkers↗