Biomedical subjects

K Araki

Publications and source records attributed to K Araki.

At least 145 records · Page 8Linked to original sources

PubMed1997

Thyroid cancer in children: report of three cases and a review of the Japanese literature.

We experienced three cases of thyroid cancer in children less than 15 years of age between 1982 and 1995. We herein present these three cases with a review of 141 reported cases of childhood thyroid cancer in Japan. Our patients were 6, 13, and 14 years old. The patients, all girls, were diagnosed as having thyroid cancer based on diagnostic imaging. One of them was also diagnosed by a fine-needle aspiration biopsy (FNAB). One of them underwent subtotal thyroidectomy, and the other two underwent lobectomy. Modified neck dissections were performed on all three. Pathologically, the tumors were all papillary carcinomas. Multiple lymph node metastases were present in all patients. However, the postoperative courses have been good, and there have been no signs of recurrence, 10, 8, and 2 years after their respective operations. In 144 reported cases of childhood thyroid cancer in Japan including ours, the youngest patient was a 2-year-old boy, and the female to male ratio was 2.1:1. FNAB was performed in 25 cases, and 23 (92%) of the tumors were diagnosed as malignant. Histologically, 76% were papillary carcinoma and 20% follicular carcinoma. At operation, lymph node metastases were found in 80% of the cases, and lung metastases in 17%. For treatment, 88% of the patients received a more extensive operation than a lobectomy. Of the 144 patients, 8 died.

Adolescent↗

PubMed1997

Varioliform mucosal polypoid lesions in intestinal tract in a patient with adult T-cell leukemia.

We describe a case of adult T-cell leukemia (ATL) with intestinal infiltration. In the early clinical stage, the endoscopic findings for the intestine were similar to those of amebic enterocolitis, i.e., varioliform mucosal polypoid lesions, and amebic cyst was detected with stool examination. Although no specific pathological factor could be identified on biopsy, the patient was treated for amebiasis as a diagnostic therapy. The findings of varioliform mucosal polypoid lesions were detected in the duodenum on endoscopic examination, but the lesions eventually disappeared during the treatment for amebiasis. We then suspected lymphoma partially masked by the amebiasis. Immunological staining of a specimen of the colonic mucosa revealed T cell invasion and Southern blotting demonstrated adult T-cell leukemia provirus invasion. Thus, ATL cell infiltration of the intestinal tract was confirmed. It is suggested that systemic disease should also be considered when varioliform mucosal polypoid lesions are found on colonoscopic examination.

Amebiasis↗

PubMed1997

Reliability of ultrasonography and sialography in the diagnosis of Sjögren's syndrome.

OBJECTIVE: The purpose of this study was to evaluate quantitatively observer performance with ultrasonography and sialography in the diagnosis of parotid gland involvement of Sjögren's syndrome. STUDY DESIGN: Sixty-four parotid gland sialograms and 65 ultrasonograms were prepared for observer performance experiments. They included both modalities in 24 Sjögren's syndrome and 19 nonspecific parotitis cases, 21 normal parotid gland sialograms, and 22 normal ultrasonograms in healthy volunteers. The images were randomly sequenced and presented to five observers who were asked to describe several findings and finally to determine the imaging diagnosis by ranking the abnormal features and the diagnosis on a five-point-rating scale. Observer performance was evaluated on the basis of the reliability of findings interpreted and the diagnostic accuracy of each modality from observers' rating scores. RESULTS: The diagnostic accuracy of sialography was very high, nearly perfect. The diagnostic accuracy of ultrasonography was lower than that of sialography, resulting from the lower incidence of characteristic findings in the disease groups and lower sensitivity on ultrasonography. In the differentiation of Sjögren's syndrome from the normal, however, the diagnostic accuracy of ultrasonography increased to 80% for all cases, and up to nearly 90% in the advanced sialographic stages. CONCLUSION: Ultrasonography is useful for the diagnosis of Sjögren's syndrome in the advanced stages. Taking the noninvasiveness of this technique into account we recommend first applying ultrasonography to the diagnosis of Sjögren's syndrome and performing sialography when no positive findings are detected on ultrasonography.

Analysis of Variance↗

PubMed1997

Morphologic analysis of odontogenic cysts with computed tomography.

PURPOSE: The purpose of this study was to analyze the effects of lesion site and epithelial keratinization on the morphologic characteristics of odontogenic cysts and clarify determinate factors for cyst morphology. MATERIAL AND METHODS: Computed tomographic images of 92 odontogenic cysts were analyzed: 31 primordial, 31 dentigerous and 30 radicular. Thirty-four cysts were located in the maxilla (6 primordial, 10 dentigerous, and 18 radicular) and 58 in the mandible (25 primordial, 21 dentigerous, and 12 radicular). Histologically, 31 cysts showed epithelial keratinization (18 primordial and 13 dentigerous). No keratinization was seen in radicular cysts. The morphologic features of cysts were assessed by measuring long length parallel to dental arch and short length vertical to it and calculating the long/short ratio. In addition, the computed tomography pattern of the cyst was classified into unilocular, lobulated, and multilocular patterns. Appearance of the sclerotic rim and surrounding cortex were classified into three and four patterns respectively to evaluate the developmental features of the cyst. RESULTS: As a whole, the long length of the primordial cysts was statistically larger than the other two cyst groups and resulted in a larger long/short ratio. Statistical differences of CT pattern were also seen among cyst groups. There was no preference in any cyst group for the appearance of the sclerotic rim and cortex. There were statistical differences between maxilla and mandible in short axis and long/short ratio. The maxillary cysts generally showed round shapes irrespective of their histologic characteristics. A multilocular pattern was more frequent in the keratinized group of mandibular primordial cysts. In dentigerous cysts, a multilocular pattern was seen only in the keratinized group and the long/short ratio was statistically larger; cyst shape was elliptical along the long axis. CONCLUSION: Our results demonstrated morphologic differences of odontogenic cysts caused by lesion site and keratinization. The dentigerous cyst with predominant keratinization should be included in the primordial cyst (odontogenic keratocyst) group.

Adult↗

PubMed1997

Cytotoxic glycosides from Albizia julibrissin.

During the course of a study of leguminous plants, cytotoxicity was demonstrated by the crude saponin fraction of Albizia julibrissin. Following chromatographic purification, the structures of three novel saponins, julibrosides I-III (1-3), inclusive of a cytotoxic principle, were elucidated. A comparison of the cytotoxicity of julibrosides (1-3) and their prosapogenins (4-15) prepared by alkaline hydrolysis clearly indicated that both an alpha-L-arabinofuranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->3)]-alpha- L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl ester unit and a monoterpene-quinovopyranosyl moiety are crucial substituents for cytotoxicity among this class of compounds. The hydroxy group at C-16 of aglycon may play an important role in mediating cytotoxicity, and the N-acetyl-glucosamine moiety at C-3 seems to enhance activity because 3 showed the strongest cytotoxicity.

Antineoplastic Agents, Phytogenic↗

PubMed1997

Two-dimensional gray-scale clustering for texture analysis.

OBJECTIVES: To develop a new quantitative method for the visual discrimination of image texture. METHODS: Two kinds of image phantoms were prepared, one for evaluating the effects of change in size and gray values of individual pixels (primitives) on perceived coarseness and the other for evaluating changes in groups of pixels (clusters) on perceived heterogeneity. The phantom images were displayed on a CRT and presented to 11 observers who assessed heterogeneity and coarseness on a 10-point scale between -5 and +5. On the basis of the observers' results, a new texture analysis method termed two-dimensional gray-scale clustering analysis was developed and applied to measure quantitatively the texture of the phantoms. The results obtained were then compared with those of the visual evaluation. RESULTS: The size of the primitives and the clusters greatly affected the visual evaluation of heterogeneity and coarseness. Changes in the gray value had only a slight effect. The intra-observer variation for heterogeneity was significantly larger than that for coarseness. Two-dimensional gray-scale clustering analysis could differentiate heterogeneity from coarseness. A high correlation was obtained between the visual evaluation and the quantitative data. CONCLUSION: Quantitative two-dimensional gray-scale clustering analysis appears to be a useful means of texture analysis.

Algorithms↗

PubMed1997

Computed tomography of carcinoma of the upper gingiva and hard palate: correlation with the surgical and histopathological findings.

OBJECTIVES: To clarify the diagnostic utility of CT in the evaluation of carcinoma of the maxillary gingiva and hard palate. METHODS: The CT scans of 27 patients with squamous cell carcinoma of the upper gingiva and hard palate were reviewed. Tumor extent and bone destruction were compared with the surgical and histopathological findings to estimate the sensitivity, specificity and accuracy of CT. RESULTS: The primary tumor was detected by CT in 89% of patients. The grade of bone destruction determined by CT correlated well with that verified at surgery or by histopathological examination. The sensitivity, specificity, and accuracy of CT for invasion to the buccal mucosa were 64%, 89% and 75% respectively. For maxillary sinus invasion, CT showed low specificity but high sensitivity. The accuracy was 86% when the criterion for sinus invasion was the presence of an enhanced mass continuous with the primary tumor. CONCLUSION: CT is helpful for the evaluation of tumor extent in the upper gingiva and hard palate carcinoma. However, invasion of the maxillary sinus should be considered carefully, because CT findings suggestive of destruction of the floor of the maxillary sinus are not always consistent with sinus invasion.

Adult↗

PubMed1997

Species-dependent migration of fish hatching gland cells that express astacin-like proteases in common [corrected].

Two constituent proteases of the hatching enzyme of the medaka (Oryzias latipes), choriolysin H (HCE) and choriolysin L (LCE), belong to the astacin protease family. Astacin family proteases have a consensus amino acid sequence of HExxHxxGFxHExxRxDR motif in their active site region. In addition, HCE and LCE have a consensus sequence, SIMHYGR, in the downstream of the active site. Oligonucleotide primers were constructed that corresponded to the above-mentioned amino acid sequences and polymerase chain reactions were performed in zebrafish (Brachydanio rerio) and masu salmon (Oncorynchus masou) embryos. Using the amplified fragments as probes, two full-length cDNA were isolated from each cDNA library of the zebrafish and the masu salmon. The predicted amino acid sequences of the cDNA were similar to that of the medaka enzymes, more similar to HCE than to LCE, and it was conjectured that hatching enzymes of zebrafish and masu salmon also belonged to the astacin protease family. The final location of hatching gland cells in the three fish species: medaka, zebrafish and masu salmon, is different. The hatching gland cells of medaka are finally located in the epithelium of the pharyngeal cavity, those of zebrafish are in the epidermis of the yolk sac, and those of masu salmon are both in the epithelium of the pharyngeal cavity and the lateral epidermis of the head. However, in the present study, it was found that the hatching gland cells of zebrafish and masu salmon originated from the anterior end of the hypoblast, the Polster, as did those of medaka by in situ hybridization. It was clarified, therefore, that such difference in the final location of hatching gland cells among these species resulted from the difference in the migratory route of the hatching gland cells after the Polster region.

Amino Acid Sequence↗

PubMed1997

Endosonography-guided endoscopic resection of duodenal carcinoid tumor.

Endoscopic resection techniques using snare polypectomy with or without submucosal saline injection have also been applied to resect smaller duodenal carcinoid tumors. We report on two patients where endoluminal ultrasound using a small diameter probe was used to visualize the adherence of the carcinoids to the underlying wall layers and the separating effect of subtumoril saline injection. One patient, in whom a clear separation between the tumor and the underlying tissue after saline injection was visualized, underwent successful endoscopic resection. In the other patient no clear separation could be achieved after saline injection and the patient underwent surgical removal of his tumor; both tumors were 1 cm or less in their maximal diameter.

Aged↗

PubMed1997

Efficiency of recombination by Cre transient expression in embryonic stem cells: comparison of various promoters.

The Cre-loxP recombination system of bacteriophage P1 is frequently utilized in genetic manipulation in embryonic stem (ES) cells. The level of Cre expression is critical to induce loxP site-specific recombination in ES cells. To compare the efficiency of recombination, we constructed four Cre expression vectors driven by different promoters: cytomegarovirus/chicken beta-actin (CAG) promoter, human polypeptide chain elongation factor 1alpha (hEF-1alpha) promoter, mouse phosphoglycerate kinase-1 (mPGK) promoter, and polyoma enhancer/herpes simplex virus thymidine kinase (MC1) promoter. We introduced these Cre expression vectors by electroporation into three ES cell lines carrying a single copy of CAG-loxP-chloramphenicol acetyltransferase (CAT) gene-loxP-beta-galactosidase (beta-gal) gene construct. Since the Cre-mediated recombination leads to excision of the CAT gene, the efficiency of recombination can be monitored as beta-gal expression. No selection system was used in the experiments. The maximum recombination frequency was obtained when the CAG promoter was used, followed by the hEF-1alpha promoter, the mPGK promoter and the MC1 promoter in order. These results indicate that the efficiency of recombination in transient expression system correlates with the promoter activity of Cre expression vector. Thus, it is important to choose the promoter for effective recombination by Cre.

Actins↗

PubMed1997

Displacement of the double-lumen endobronchial tube can be detected by bronchial cuff pressure change.

We measured the bronchial cuff pressure of left-sided double-lumen endobronchial tubes (DLTs) in 54 patients to confirm the effect of DLT displacement on cuff pressure. After positioning the cephalad surface of the bronchial cuff of the DLT 2.5 cm distal to the carina (23 patients in the first part of the study) or just below the carina (23 patients in the second part), the cuff was withdrawn in 0.5-cm steps during right-sided, one-lung ventilation. The bronchial cuff pressure was measured, and the capnogram and pressure-volume loop, displayed by a side-stream spirometer, was evaluated. After positioning the cephalad surface of the bronchial cuff just below the carina (eight patients in the third part), bronchial cuff pressure was measured while confirming the position of the bronchial cuff during the 30 min of the operative procedure. The bronchial cuff pressure decreased significantly by 28.4 cm H2O (P < 0.01) and 21.3 cm H2O (P < 0.01) in the first and second parts, respectively, before the pressure-volume loop or the capnogram changed. The bronchial cuff pressure in the third part showed no significant change. We conclude that bronchial cuff pressure monitoring was very helpful in detecting displacement of the DLT during right-sided, one-lung ventilation.

Adult↗

PubMed1997

Effects of self washout structure on the antithrombogenicity and the hemolytic properties of a centrifugal pump.

Antithrombogenicity in an initial type (N1) of a centrifugal pump (CP) developed in our institute is provided by the central balancing hole of an impeller. A new CP (N2) was modified to obtain better antithrombogenicity, in which the balancing hole was widened to improve self washout flow velocity (Vsf), and an edge of the thrust bearing was rounded off to minimize flow separation. Effects of the modifications were assessed in vitro and in vivo studies. The Vsf of the N1 and the N2 evaluated by a Doppler velocimeter were 12.8 and 22.1 cm/s, respectively. Flow around the thrust bearing, which was visualized by a light cutting method, confirmed less flow stagnation in the N2. The hemolytic indices of the N1 and the N2 were 0.023 and 0.008 mg/dl, respectively. In vivo antithrombogenicity and the hemolytic properties of the N2 and the N1 were investigated without anticoagulation therapy in 3 goats. In each goat the N2 was driven for 1 week and exchanged for the N1, which was driven for the same period. Red thrombi at the thrust bearing were found in 2 N1s, and 2 small thrombi were on the impeller of another N1, whereas a thrombus of less than 1 mm3 at the TB was noted in 1 N2. Plasma free hemoglobin was not increased in either CP. These results indicate that the N2 has better antithrombogenicity and hemolytic properties than the N1.

Animals↗

PubMed1997

Scalp-recorded, ictal focal DC shift in a patient with tonic seizure.

PURPOSE: We recorded focal ictal DC shifts from scalp electrodes in a 9-year-old boy with intractable, clinically generalized tonic seizures. The patient had a high intensity signal abnormality of the left temporal cortex with thickening of the gyri on T2-weighted MRI. METHODS: Scalp digital EEGs were recorded using electrodes made of silver/silver chloride. The low frequency filter (LFF) was set at 0.016 Hz. Recorded seizures were subsequently analyzed with LFF settings of 1.0, 0.016 and 0.03 Hz. RESULTS: All recorded seizures initially showed diffuse, low voltage, high frequency activity (electrodecremental pattern) followed 10-20 s later by quasirhythmic activity over the left frontotemporal region. In two seizures, LFF of 0.016-0.03 Hz revealed a slow negative shift over the left frontotemporal area simultaneously with onset of the bilateral electrodecremental pattern. However, in the other seizures, this initial slow negative shift was obscured by artifacts. Subsequent electrocorticography (ECoG) delineated frequent epileptiform discharges in the left temporal as well as frontal cortex. CONCLUSIONS: Scalp-recorded ictal DC shifts may help identify focal epileptogenic brain area in patients with clinically generalized seizures although the technique is vulnerable to artifact.

Child↗

PubMed1997

[Isolation frequency and biological characteristics of the multiple-antibiotic resistant Pseudomonas aeruginosa isolated from clinical specimens].

Isolation frequency of multiple-antibiotic resistant Pseudomonas aeruginosa (MARPA) was 11.9% (fifty six strains) of a total of four-hundred seventy-one strains of P. aeruginosa isolated from clinical specimens at the Kyorin University Hospital from October 1994 to December 1996. Eighteen strains of MARPA and thirteen strains of antibiotic sensitive P. aeruginosa (ASPA) isolated from clinical specimens in internal medicine ward A were determined O serotype, and characterized with production of pyocyanin, pyoverdin, hemolysin, elastase, and caseinase. Sixteen strains (88.9%) of MARPA were identified as serotype C. The ability to produce pyocyanin, hemolysin, elastase, and caseinase was not detected in all MARPA. One side, thirteen strains of ASPA showed various serotypes, i.e., B: 5 strains (38.4%), G: 4 strains (30.8%), C: 2 strains (15.4%), E: 1 strain (7.7%) and unknown type: 1 strain (7.7%), and the production of both hemolysin and pyoverdin was observed in 13 strains (100%), pyocyanin in 8 strains (61.5%), elastase and caseinase in 9 strains (69.2%) of ASPAs, which suggests that ASPAs do maintain the synthetic ability of pathogenic factors and pigments, but MARPAs do not. These results indicate that from epidemiological points of view the current strains of MARPA spread from one clone within the internal medicine ward A with nosocomial outbreak by serotype C.

Ampicillin Resistance↗

PubMed1997

An immuno- and enzyme cytochemical study of the H(+)-K+ ATPase in human parietal cells after administration of tetragastrin and omeprazole.

The presence of subunit proteins, 1H9 for the alpha-subunit and 2B6 for the beta-subunit, of H(+)-K+ ATPase and its activity in tubulovesicles and intracellular canaliculi of gastric parietal cells were immunocytochemically and enzyme cytochemically examined. Specimens were taken from healthy human volunteers by endoscopic biopsy in resting, tetragastrin-stimulated and omeprazole-inhibited conditions. H(+)-K+ ATPase was present in both intracellular canaliculi and tubulovesicles in these three conditions. Gold particles of the alpha-subunit decreased in number, and those showing the beta-subunit increased under both gastrin-stimulating and omeprazole-inhibiting conditions compared with parietal cells in the resting state. We suggest that the administration of tetragastrin and omeprazole alter the turnover rate of each subunit of H(+)-K+ ATPase, resulting in the difference of the proportions of alpha- and beta-subunits. Moreover, the activity of H(+)-K+ ATPase was detected strongly beneath the membrane of microvilli and weakly in that of tubulovesicles under these three conditions. After 7 days of daily oral omeprazole intake, H(+)-K+ ATPase in parietal cells were detected in intracellular canaliculi and tubulovesicles. However, the H(+)-K+ ATPase activity in tubulovesicles was diminished 1 h after omeprazole intake, and the activity in intracellular canaliculi was completely inhibited even 3 h after omeprazole administration. These results show that omeprazole inhibited the H(+)-K+ ATPase activity in both intracellular canaliculi and tubulovesicles.

Adult↗

PubMed1997

Dirofilaria immitis: experimental infection of rabbits with immature fifth-stage worms.

To establish an animal model for human pulmonary dirofilariasis, we experimentally infected nine rabbits with immature fifth-stage worms of Dirofilaria immitis. The rabbits were infected by subcutaneous transplantation with various numbers of immature worms collected from 110- and 120-day-old infections of dogs. Four of seven rabbits infected with up to four larvae possessed encapsulated worms in the lungs at 196 or 308 days post-transplantation. Two rabbits transplanted with eight worms died of pulmonary hemorrhagic infarction 18 and 28 days post-transplantation. Marked histopathologic changes were observed in the lungs at the site of degenerating worms, which were encapsulated by a fibrous wall. Severe to mild infiltrations with eosinophils, heterophils, lymphocytes, plasma cells, and histiocytes were found in granulomas and their surrounding areas. The findings in these rabbits resemble those reported for human cases of pulmonary dirofilariasis.

Animals↗

PubMed1997

[Surgical treatment of aortic valve regurgitation due to nonpenetrating trauma of the chest--a case report and review of the literature in Japan].

A case report and a literature review of the patients in Japan who underwent surgical treatment of an aortic valve regurgitation due to nonpenetrating chest trauma are presented. A 70-year-old man was admitted to our hospital with multiple trauma, including fracture of sternum, caused by traffic accident. After treatment of respiratory and circulatory failure, he was found to have aortic regurgitation and subsequent congestive heart failure. The aortic valve replacement was performed and his postoperative course was good. The tear of aortic valve was detected in the noncoronary cusp, and the size of the tear was 4 mm. The aortic valve was not recognized the findings of inflammatory or rheumatic changes. Before this case, 15 cases were operated in Japan with the diagnosis of traumatic aortic regurgitation. We reviewed them in the table.

Accidents, Traffic↗

PubMed1997

[A study on the quantitative evaluation method of human alertness and its application].

This article presents an alertness evaluation method being analyzed by the authors, and discusses its application. With the aim of quantifying the physiological activity of the living body, the alpha-attenuation test (AAT) for evaluation of alertness was assessed. AAT is a method of quantitatively determining alertness level from alpha-wave power spectra during eye closure and opening. 1. The potential for quantification of diurnal change of alertness by the use of the AAT is suggested. Also rated, are a performance evaluation method based on reaction time and target tracking error and a subjective feeling evaluation method using an analog scale on a computer display. Using these methods of evaluation, measurements were made in 9 healthy men and women at 2-hour intervals over the period from 09: 30 to 19: 30. The findings are summarized as follows: 1) Alertness lowered from 13: 30 to 15: 30, as rated by diurnal change determined by the AAT 2) The performance test and subjective feeling scoring revealed decreased target tracing ability and extended reaction time from 13: 30 to 15: 30, accompanied by reduced performance, increased sleepiness, and failure to achieve accurate, quick action. 2. The relation between the quality of rest and the alpha-attenuation coefficient (AAC), the quantitative index of the AAT, was rated. There were some statistical significances between the quality of rest and the AAC. These results suggest that the AAC is found applicable to the quantitative assessment of diurnal changes of physiological activity, and that the AAC is reflected in the quality of rest.

Adult↗