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Biomedical subjects

K Ushio

Publications and source records attributed to K Ushio.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Pathological localization of benign paroxysmal positional vertigo--from three-dimensional analysis of nystagmus].

Although it has been speculated that benign paroxysmal positional vertigo (BPPV) derives from the utricle or posterior semicircular canal, the origin of BPPV is still controversial. In this study, we investigated the role of the utricle and semicircular canals (especially the vertical semicircular canal) relative to BPPV by three-dimensional analysis, focusing on the horizontal, vertical, and torsional positions by applying our computerized eye movement analysis system. In 13 subjects who were diagnosed as having BPPV, we carried out the positioning nystagmus tests, and analyzed three components of nystagmus. By using a pendular rotation stimulus, we also measured three components of eye movement elicited from the vertical semicircular canals in 5 normal subjects and 2 subjects from whom acoustic tumors were removed by the translabyrinthine approach. We compared two components (vertical and torsional) of BPPV with those of eye movements elicited from the vertical semicircular canals. In BPPV, the slow phase velocity of the torsional component was greater than that of the vertical component. Conversely, the amplitude of the vertical component from the vertical semicircular canals was greater than that of the torsional component. From these results, by analyzing the vestibuloocular reflex of vertical semicircular canals, it is difficult to support the idea that the pathology of BPPV is located in the posterior semicircular canal alone.

Adult↗
PubMed1997

3D analysis of nystagmus during peripheral vertiginous attacks.

In order to localize the site of lesion of peripheral vertigo, 3D analysis of nystagmus during peripheral vertiginous attacks was carried out. In comparison between the three components, the horizontal component had the largest ratio in each disease. Spontaneous nystagmus was directed toward the affected side in 3 cases and to the opposite side in 15. In patients with Menière's disease (MD), all subjects had horizontal and torsional components and had almost the same slow phase velocity in these two components. In patients with vestibular neuritis (VN) and Hunt's syndrome (HS), nystagmus was directed toward the opposite side. Furthermore, in VN, all subjects had an upward component, in addition to horizontal and torsional components. Inferring the focus from the character of nystagmus, it is speculated that the pathological changes are located in the entire inner ear in MD, whereas in VN the lesion is located in the horizontal and anterior semicircular canal or the superior vestibular nerve.

Adult↗
PubMed1996

Clinical implications of microsatellite instability in colorectal cancers.

BACKGROUND: Microsatellite instability (MI) has been reported in some sporadic colon tumors and in cases of hereditary nonpolyposis colorectal cancer (HNPCC). The criteria for HNPCC have not been fully defined, and clinical criteria are used to identify as many HNPCC patients as possible. To clarify the conformity of these criteria with the identification of eligible HNPCC cases, we analyzed MI in HNPCC patients diagnosed using clinical criteria. METHODS: Genomic DNA was extracted from surgical specimens of 56 colorectal cancers, including 36 from patients diagnosed with HNPCC using the clinical criteria. We analyzed four microsatellite loci using 32P-labeled primers. RESULTS: Among HNPCC patients diagnosed using clinical criteria, patients who were positive for MI accounted for 62% of Group A (a confirmed group) and 35% of Group B (a high risk group); only 5% of randomly selected colorectal cancer patients (Group C), were positive for MI. Furthermore, MI-positive tumors were found in patients who had a tendency for tumors to involve the right side of the colon, an association with cancers in other organs, a lower incidence of p53 protein positivity, and a higher proportion of poorly differentiated cancers. CONCLUSIONS: The presence of MI, in concert with modified clinical criteria, may identify legitimate cases of HNPCC in patients who might otherwise be excluded by the minimum criteria.

Age of Onset↗
PubMed1996

CT diagnosis of intraductal papillary neoplasm of the pancreas in comparison with histopathologic findings.

CONCLUSION: The existence of excrescent nodules in the cystic component of intraductal papillary neoplasms (IPN) on computed tomography (CT) is useful for differentiating between malignant and benign lesions. BACKGROUND: We sought to evaluate the ability of CT to differentiate malignant from benign lesions in IPN of the pancreas. METHODS: CT findings in 20 cases of IPN (11 benign and 9 malignant lesions) were compared with histopathological findings from subsequent surgery. RESULTS: The size of the cystic portion on CT did not correlate with the malignant potential of the lesion. Seven (78%) of 9 malignant lesions had excrescent nodules on CT, whereas 1 (9%) of 11 benign lesions did.

Adenoma↗
PubMed1996

Serous cystadenoma of the pancreas communicating with a pancreatic duct.

CONCLUSION: To differentiate serous cystadenoma from other cystic lesions communicating with the pancreatic duct, careful radiological examination is necessary. BACKGROUND: Communication between the cystic cavity and the pancreatic duct in an ordinary serous cystadenoma is uncommon, although it is not uncommon in other cystic lesions, such as pseudocyst, mucinous cystadenoma/adenocarcinoma, and intraductal papillary tumor. METHODS. A serous cystadenoma of the pancreas communicating with main pancreatic duct in a 76-yr-old male is reported. RESULTS: The communication was preoperatively demonstrated by endoscopic retrograde cholangiopancreatography and confirmed by histopathological examination of the resected specimen.

Aged↗
PubMed1996

Molecular nature of colon tumors in hereditary nonpolyposis colon cancer, familial polyposis, and sporadic colon cancer.

BACKGROUND & AIMS: Microsatellite instability (replication error [RER]) is a characteristic of tumors in hereditary nonpolyposis colon cancer (HNPCC), but the mechanism of HNPCC carcinogenesis is not yet understood. To clarify the nature of HNPCC tumors, RER and genetic changes were compared between HNPCC and non-HNPCC tumors. METHODS: RER and genetic changes were analyzed in 21 HNPCC, 389 familial adenomatous polyposis, and 206 sporadic tumors using polymerase chain reaction, single-strand conformation polymorphism, sequencing, and Southern hybridization. RESULTS. in HNPCC, 95% tumors at all stages showed RER positivity (altered loci, 4.3 of 5). In familial adenomatous polyposis and sporadic tumors, RER positivity (1.7 of 5) was 3% in adenoma and intramucosal carcinoma, 13%-24% in invasive carcinoma, and 35% in carcinoma metastasized to liver. Fifty percent of RER-positive HNPCC tumors had both germline and somatic mutations of hMSH2 or hMLH1 gene, whereas 6% of RER-positive non-HNPCC had somatic mutation. APC, p53, and K-ras-2 mutations and loss of heterozygosity of tumor-suppressor genes were significantly less frequent (P = 0.03 to 0.0006) but transforming growth factor beta type II receptor mutation was significantly more frequent (P = 0.000001) in HNPCC than in non-HNPCC. CONCLUSIONS: RER positivity occurs from an early stage of carcinogenesis in HNPCC but in later stages in non-HNPCC. Most HNPCC tumors may develop through different genetic changes from those in the adenoma-carcinoma sequence, although a certain percentage develops through APC mutation.

Adaptor Proteins, Signal Transducing↗
PubMed1996

Prognosis of hereditary nonpolyposis colorectal cancer (HNPCC) and the role of Japanese criteria for HNPCC.

In 1991, the Japan Research Society for Cancer of the Colon and Rectum proposed clinical criteria (Japanese criteria) for hereditary nonpolyposis colorectal cancer (HNPCC). According to the Japanese and Amsterdam criteria, three groups of patients are defined: 1) those diagnosed as having HNPCC using the Amsterdam criteria (Amsterdam HNPCC); 2) those classified as Japanese criteria category A (putative HNPCC-A) and 3) those classified as Japanese criteria category B (putative HNPCC-B). In order to evaluate the prognosis of HNPCC and the role of the Japanese criteria, the clinicopathological characteristics, recurrence and survival rates of Amsterdam HNPCC (n 14) and putative HNPCC-A (n 31) and B (n 100) patients were studied, and compared with those of patients with sporadic colorectal cancer (controls, n 1604). The Amsterdam clinicopathological characteristics and those of putative HNPCC were the same as those reported previously. Neither local nor distant recurrences were observed in the Amsterdam HNPCC and putative HNPCC-A during a median follow-up period of 137 months. The 5-year survival rates of the Amsterdam HNPCC, putative HNPCC-A, B, and control patients were 92.3%, 81.2%, 66.5% and 60.0%, respectively, and those of the former two groups were significantly better than those of the others (P<0.05). These results show that the prognosis of HNPCC is better than that of sporadic colorectal cancer, and that the Japanese criteria, especially for category A, can be used to select putative HNPCC patients from among those with sporadic colorectal cancers.

Adult↗
PubMed1996

Loss or somatic mutations of hMSH2 occur in hereditary nonpolyposis colorectal cancers with hMSH2 germline mutations.

Hereditary nonpolyposis colorectal cancer (HNPCC) is a major cancer susceptibility syndrome known to be caused by the inheritance of mutations in DNA mismatch repair genes, such as hMSH2, hMLH1, hPMS1 and hPMS2. To investigate the role of genetic alterations of hMSH2 in HNPCC tumorigenesis, we analyzed 36 Japanese HNPCC kindreds as to hMSH2 germline mutations. Moreover, we also examined somatic mutations of hMSH2 or loss of heterozygosity at or near the hMSH2 locus in the tumors from the hMSH2-related kindreds. Germline mutations were detected in five HNPCC kindreds (5/36, 14%). Among them, three were nonsense mutations, one was a frameshift mutation and the other was a mutation in an intron where the mutation affected splicing. Loss of heterozygosity in four and somatic mutations in one were detected among the eight tumors with hMSH2 germline mutations. All these alterations were only detected in genomic instability(+) tumors, i.e., not in genomic instability(-) ones, indicating that mutations of hMSH2 were responsible for at least some of the tumors with genomic instability. These data establish a basis for the presymptomatic diagnosis of HNPCC patients, and constitute further evidence that both DNA mismatch repair genes and tumor suppressor genes may share the same requirement, i.e., two hits are necessary to inactivate the gene function.

Alleles↗
PubMed1996

Computed tomography of pancreatic adenocarcinoma: comparison of tumor size measured by dynamic computed tomography and histopathologic examination.

Our objective was to assess the detection rate and the accuracy of tumor size determination in pancreatic ductal adenocarcinoma using dynamic computed tomography (CT). Preoperative dynamic CT was evaluated in 35 surgically resected pancreatic ductal adenocarcinomas and the findings were compared with the results of histopathological examination. Pancreatic adenocarcinoma was visualized by dynamic CT as a low-density mass in 97% of cases. All three lesions < or = 2 cm in size were demonstrated in good contrast to normal pancreatic parenchyma. The tumor size measured on dynamic CT showed a good correlation with that measured histopathologically, especially in small tumors. Dynamic CT was useful for evaluating the extent of pancreatic adenocarcinoma, especially for small tumors. The detectability of lesions by CT depended on the manner of tumor extension and the degree of associated pancreatitis as well as the tumor size.

Adenocarcinoma↗
PubMed1995

Germ line mutations of hMSH2 and hMLH1 genes in Japanese families with hereditary nonpolyposis colorectal cancer (HNPCC): usefulness of DNA analysis for screening and diagnosis of HNPCC patients.

Mutations in hMSH2 and hMLH1 genes were analyzed in patients from 11 Japanese families that had been diagnosed as carrying hereditary nonpolyposis colorectal cancer (HNPCC) by clinical examination. Germ line mutations of hMSH2 gene were identified in 5 independent families in which colorectal (87% of patients), endometrial (30%), ovarian (17%), gastric (14%), and other cancers existed. Five mutations detected between codons 136 and 811 included single-base substitutions (C-->T and T-->G), a T deletion, and an A insertion, all of which produced stop codons resulting in truncated proteins, and an A-->T substitution at splice donor site of exon 5 which resulted in deletion of this exon. Moreover, one HNPCC family was presumed to have germ line mutation of hMSH2 gene because a somatic mutation of hMSH2 gene was detected in a cancer from a patient in this family. In addition to these 11 families already diagnosed with HNPCC, 3 new families with germ line mutations of hMSH2 gene and hMLH1 gene were found through analysis of DNA from patients who had multiple cancers with alteration in microsatellite DNA. These mutations included an AG deletion at codons 877-878 of hMSH2 gene, an AAG deletion at codons 616-618 of hMLH1 gene, and a C-->T single-base substitution at codon 217 of hMLH1 gene. Seven of eight germ line mutations found in this study are new mutations that have not been reported previously. In families in which germ line mutations were identified presymptomatic examination was then carried out using polymerase chain reaction single-strand conformation polymorphism analysis of DNA from peripheral blood, and the result was the detection of family members predisposed to HNPCC who did not yet show signs of cancer. These results indicate the value of DNA analysis in the screening and diagnosis of HNPCC patients and families.

Adult↗
PubMed1995

Ductal adenocarcinoma of the pancreas associated with intratumoral calcification.

An invasive ductal carcinoma of the pancreas with intratumoral calcification is reported in a 59-yr-old female. The calcification was preoperatively demonstrated by ultrasonography and computed tomography. On the cut surface of the resected specimen of the pancreas tail, calcification was observed in the central part of the ductal adenocarcinoma. Although calcification is not uncommon in chronic pancreatitis or serous cystadenoma, mucinous cystadenoma/adenocarcinoma, solid and cystic tumor, and islet cell tumor, intratumoral calcification is uncommon in an ordinary ductal adenocarcinoma of the pancreas. For differential diagnosis from other conditions associated with calcification, careful examinations are necessary.

Calcinosis↗
PubMed1995

Three-component analysis of benign paroxysmal positional nystagmus.

Three-component analysis of Benign Paroxysmal Positional Nystagmus (BPPN), focusing on the horizontal, vertical, and torsional, using a computerized eye movement analysis system, was carried out in 10 patients. Using a pendular rotation stimulus, we also measured three components of eye movement elicited from the vertical semicircular canals in normal subjects. We compared two components (vertical and torsional) of BPPN with that of eye movements elicited from the vertical semicircular canals. In BPPN, the torsional component of eye movements was larger than that of the vertical component. Conversely, the vertical component from the vertical semicircular canals was larger than that of the torsional component. From these results, by analysing the vestibulo-ocular reflex of the vertical semicircular canals, it is difficult to support the idea that the pathology of the BPPV is localized in the posterior semi-circular canal alone.

Electronic Data Processing↗
PubMed1995

Nystagmus in benign paroxysmal positional vertigo: a three-component analysis.

Three-component analysis of nystagmus was carried out in 10 patients with benign paroxysmal positional vertigo (BPPV), focusing on the horizontal, vertical and torsional components, with the aid of a computerized eye movement analysis system. Using a pendular rotation stimulus we also measured three eye components of eye movement evoked from the vertical semicircular canals in 3 normal subject; two components (vertical and torsional) of nystagmus in patients with BPPV were compared with that of eye movements derived from the vertical semicircular canals. The time course of slow phase velocity of three components in BPPV patients was similar. In BPPV, the torsional component of eye movements was larger than that of the vertical component without obvious horizontal eye deviation. On the other hand, the vertical component from vertical semicircular canals was larger than that of the torsional component. From the view point of the vestibulo-ocular reflex, it is difficult to support the idea that the pathology of BPPV is localized only to the posterior semicircular canal.

Electronystagmography↗
PubMed1994

Clinical application of IS & C system in the National Cancer Center Hospital.

The National Cancer Center, Japan, has two hospitals at present, and these two hospitals are in the process of sharing their respective split clinical functions. On the other hand, patients may visit one or both hospitals, in many cases depending on their need and convenience, for which both hospitals should maintain the same clinical level to comply with the needs of the patients by a common access to the individual medical data and information. Therefore, the possibility of transmitting such medical information between the two hospitals using the IS & C system has been studied, and such a system has almost been completed for the transmission of endoscopic images. No problems exist in terms of interchangeability; however, it is necessary to integrate it with the hospital information system to avoid a complicated keyboard process before practical endoscopic examination.

Cancer Care Facilities↗
PubMed1992

[Determination of protoporphyrins in blood using HPLC. Standardization of protoporphyrins and interlaboratory comparison of analyses].

1) In order to compare the results of determination of protoporphyrin IX (PP) and zinc protoporphyrin IX (ZP) using HPLC, the preparation procedures for standard solutions of PP and ZP were studied at four laboratories. According to the methods mutually agreeable to the four laboratories, the absorption values using UV-Vis spectrometer from the 4 laboratories were found to be identical. 2) The total of 28 whole blood samples obtained from the same workers whose Pb-B levels ranged from 2.9 to 87.9 micrograms/dl were sent to the 4 laboratories for determination of PP and ZP. The laboratories were allowed to use their own HPLC apparatus, column, mobile phase and fluorometric detectors, although the same procedures were used to prepare the standard solutions of PP and ZP. The results showed that significant biases in ZP and PP levels were found between two out of the 4 laboratories, but the ZP values corrected by the recovery rate showed no statistical difference among the laboratories. 3) Blood levels of ZP, total protoporphyrin (TP, calculated by PP+ZP/1.1), and PP determined by HPLC method correlated well with free erythrocyte protoporphyrin (FEP) determined by the method of extraction into the acidic solvent. The correlation coefficients between Pb-B and log TP, ZP, FEP or PP were 0.82-0.84, 0.80-0.83, 0.786, or 0.70-0.73, respectively. 4) The coincident ratios of PP/TP obtained at 4 laboratories ranged from 12.1 to 19.0%. These values were within a relatively narrow range, although two different kinds of organic solvents (DMF: N',N'-dimethylformamide or Methanol/triton-X 100) were used in the extraction steps.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromatography, High Pressure Liquid↗
PubMed1992

[Effect of hydrolysis conditions on the determination of urinary 2,5-hexanedione in workers exposed or not exposed to N-hexane].

In order to determine the optimal conditions of acid hydrolysis for urinary 2,5-hexanedione (HD) measurement, the effects of urine pH or volume of HCl added to urine and hydrolysis period were studied using gas chromatography-mass spectrometry (GC-MS). When 0.3 ml of concentrated HCl was added to 3 ml of urine, complete hydrolysis to liberate HD was attained 2 h after the start of heating at 100 degrees C for urine from non-exposed subjects. On the contrary, in urine from exposed subjects most of HD was liberated in 30 min at 100 degrees C, suggesting that the urinary substrates converted to HD by acid hydrolysis were different between exposed and non-exposed subjects. It was confirmed that hydrolysis for 2 h at 100 degrees C with 0.3 ml of concentrated HCl added to 3 ml of urine gave the most reliable levels and the greatest amounts of HD in both urine from exposed and non-exposed subjects. Reference values were determined by the hydrolysis conditions presented here. In 84 males, 52 females, and 136 with sexes combined the urinary HD levels were 0.35, 0.49, and 0.39 mg/l (geometric mean), respectively. Urinary HD levels determined without hydrolysis (free HD) were less than 0.006 mg/l in 31 control subjects examined. In urine from exposed subjects the amount of free HD was about one-fifth of the total HD (free plus conjugated HD) as determined with acid hydrolysates, although the percentage of free to total HD varied from 0.4 to 28%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗