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Biomedical subjects

K Kitahara

Publications and source records attributed to K Kitahara.

At least 55 records · Page 3Linked to original sources
PubMed1996

Changes in descemet membrane and endothelium after corneal epithelial abrasion alone and with photorefractive keratectomy in rabbits.

OBJECTIVES: To investigate the effects of epithelial abrasion on the corneal endothelium and Descemet membrane in rabbits and to compare the changes with those after excimer laser photoablation of the cornea. METHODS: Central epithelial abrasions, 6 mm in diameter, were created by mechanical removal of the cells, and the specimens were examined from 24 hours up to 30 days by transmission electron microscopy. Corneas that were photoablated by an excimer laser and nontreated normal corneas were investigated as controls. RESULTS: Corneas denuded of epithelium showed massive enlargement of the mitochondria in the endothelium and exhibited a layer of electron-dense fibrillogranular material that had migrated forward through the Descemet membrane. These alterations were similar to the changes observed after photoablation of the cornea by an excimer laser. CONCLUSION: It was postulated that the extrusion of electron-dense material in the Descemet membrane observed after excimer laser ablation might have occurred primarily not as a result of shock waves, but from destruction of the epithelial integrity.

Animals↗
PubMed1996

Diffuse ganglioneuromatosis with plexiform neurofibromas limited to the gastrointestinal tract involving a large segment of small intestine.

A rare case of diffuse ganglioneuromatosis with plexiform neurofibromas limited to the gastrointestinal tract in a 20-year-old man is reported. The patient had no cafe-au-lait spots or any apparent tumorous lesions affecting other organs. A fan-shaped resection of the mesentery, including 200cm of the ileum, together with ileocecal resection was done, and the diagnosis was histologically confirmed. The relationship between this benign tumor and other neurogenic disorders is discussed, along with a review of the literature. Long-term follow up of this patient is required because of the possible development of von Recklinghausen's disease or multiple endocrine neoplasia type IIb.

Adult↗
PubMed1996

N-terminal sequence of amino acids and some properties of an acid-stable alpha-amylase from citric acid-koji (Aspergillus usamii var.).

An acid-stable alpha-amylase (AA) was purified from an acidic extract of citric acid-koji (A. usamii var.). The N-terminal sequence of the first 20 amino acids of the enzyme was identical with that of AA from A. niger, but the two enzymes differed in molecular weight. HPLC analysis for identifying the anomers of products indicated that the AA hydrolyzed maltopentaose (G5) at the third glycoside bond predominantly, which differed from Taka-amylase A and the neutral alpha-amylase (NA) from the citric acid-koji.

Amino Acid Sequence↗
PubMed1996

Intraocular hemorrhage developing during interferon therapy.

A 43-year-old man with chronic active hepatitis C was treated with interferon-beta (IFN-beta) at a dosage of 6 x 10(6) IU/day for a planned 6-week period. Ocular hyperemia, ophthalmalgia, and increased intraocular pressure in the right eye developed 20 days after the start of treatment. Intraocular pressure remained high, even after discontinuation of IFN therapy, laser therapy, and iridectomy. Two days later, the right eye was removed because perforation had occurred. The ocular symptoms that developed in this case were thought to have been caused and exacerbated by IFN administration.

Adult↗
PubMed1996

Intrahepatic portosystemic venous shunt: report of two cases assessed by helical computed tomography.

BACKGROUND: Three-dimensional (3D) anatomic analysis was carried out, using helical computed tomography (helical CT), to evaluate its usefulness in two cases of large intrahepatic portosystemic venous shunt (IPSVS). METHODS: Case 1, a 74-year-old man with type-C hepatitis, underwent hepatic angiography to confirm suggested IPSVS of the left hepatic lobe in 1994. Case 2, a 62-year-old woman with liver cirrhosis associated with type-B hepatitis, was hospitalized for evaluation of suspected hepatocellular carcinoma in 1994. Hepatic angiography disclosed a large IPSVS in the right hepatic lobe. Retrospective evaluation of CT showed that the size of this shunt had increased over the 5 years 3D anatomic analysis was carried out, and the shunt vessels were clearly demonstrated. CONCLUSION: 3D anatomic analysis using helical CT was less invasive and useful for evaluating large IPSVS.

Aged↗
PubMed1996

Expression of cyclin D1, CDK4 and p27KIP1 is associated with the p16MTS1 gene status in human esophageal carcinoma cell lines.

p16MTS1/INK4A negatively regulates cell cycle progression by inhibiting the cyclin D/CDK4 complex that phosphorylates pRb. Frequent homozygous deletions of the p16 gene were recently found in various tumor cell lines. We examined the relationship between the genetic status of p16 and the expression of the cell cycle regulating molecules in human esophageal carcinoma cell lines. Out of eight human esophageal carcinoma cell lines, seven (67.5%) and six (75%) cell lines showed homozygous deletions of the p16 and p15 genes, respectively. All the p16-negative cell lines expressed high levels of cyclin D1, CDK4 and p27KIP1 proteins. Interestingly, the expression level of cyclin D1 was closely correlated to the levels of not only CDK4 but also p27KIP1 protein in p16-negative cell lines. Furthermore, all the p16-negative cell lines expressed Rb protein of approx 110 kDa which corresponds to the phosphorylated form, whereas the cell line with intact p15 and p16 genes did not express pRb. These results suggest that the expression of cyclin D1, CDK4, Rb and p27 is associated with the p16 gene status in esophageal carcinoma cell lines. Alternatively, loss of the p16 gene and subsequent over-expression of cyclin D1 and CDK4 might be involved in autonomous growth of esophageal carcinoma cells.

Adenocarcinoma↗
PubMed1995

Concurrent amplification of cyclin E and CDK2 genes in colorectal carcinomas.

The genetic changes of cyclin A, DI, E and CDK2 were examined in human colorectal carcinomas by Southern-blot analysis. Gene amplification of cyclin E was detected in 5 of 53 (9.4%) primary colorectal carcinoma tissues. Interestingly, in 3 of 5 tumors showing cyclin E gene amplification, the CDK2 gene was amplified simultaneously with rearrangements. No obvious correlation was detected between gene amplification and clinicopathological features of colorectal carcinomas. Out of 7 colon carcinoma cell lines, 2 showed gene amplification of cyclin E without gene amplification of CDK2. No amplification of cyclin A or DI gene was found in any of the colorectal carcinoma tissues or colon carcinoma cell lines. Our results suggest that the concurrent amplification of cyclin E and CDK2 genes may play a role in colorectal carcinogenesis.

Aged↗
PubMed1995

Frequent amplification of the cyclin E gene in human gastric carcinomas.

We searched for genetic alterations of the cyclin D1 and cyclin E genes in 45 human gastric carcinoma tissues. Expression of cyclin E mRNA and protein was also analyzed in eight of them by Northern and Western blots and immunohistochemical staining. The cyclin E gene was amplified 3-10 fold in seven gastric cancer tissues (15.6%), of which six were advanced gastric cancers. All of the cases with the cyclin E gene amplification displayed lymph node metastasis. Moreover, the case with the gene amplification overexpressed the cyclin E mRNA and protein. One of eight gastric cancer cell lines, MKN-7, shared the cyclin E gene amplification, and all of the gastric cancer cell lines expressed high levels of the cyclin E mRNA and protein even without gene amplification. Amplification of the cyclin D1 gene was not observed in any of the gastric carcinoma tissues or gastric carcinoma cell lines. These results suggest that the gene amplification and overexpression of cyclin E play an important role in the abnormal growth and progression of gastric carcinoma.

Aged↗
PubMed1995

Serial transesophageal echocardiography imaging of a postoperative aortic ring abscess: a case report.

Transesophageal echocardiography (TEE) was used for the serial observation of a postoperative perivalvular abscess of a prosthetic aortic valve in a 65-year-old man who underwent aortic valve replacement for aortic regurgitation. Five months later, TEE revealed an aortic ring abscess. Ascending aortic grafting (Bentall method) and translocation of the aortic prosthetic valve were conducted for progressive mechanical valve dysfunction. Postoperative TEE showed flow between the left ventricular outflow tract and the abscess, which was unrestricted 1 month later. Associated clinical improvement suggested that washout of the abscess was a critical factor. This case illustrates the usefulness of TEE for examining postoperative aortic ring abscess.

Abscess↗
PubMed1995

Hepatopancreatoduodenectomy for squamous and adenosquamous carcinoma of the gallbladder.

The characteristics of squamous or adenosquamous cell carcinoma of the gallbladder differ quite markedly from those of adenocarcinoma, although the incidence is extremely low. Recently, we encountered both of the former types of gallbladder carcinoma: a 77-year-old man with squamous cell carcinoma and a 70-year-old man with adenosquamous cell carcinoma of the gallbladder. Both had a large mass in the gallbladder fossa region with infiltration to the liver and invasion of the duodenum. Hepatopancreatoduodenectomy was performed on both of these patients. The TNM stage of the former was IV (T4N0M0) and of the latter IV (T4N0M0) and of the latter IV (T4N1bM0). The former has remained well without recurrence for about 1 year and 4 months after the operation, while the latter died of recurrent disease 6 months after operation. The true reason for the difference in the prognosis of these two patients was not known. However, hepatopancreatoduodenectomy is considered to be a most adaptable operative procedure for squamous or adenosquamous cell carcinoma of the gallbladder in view of their mode of spread, and the presence of lymph node metastasis might be a factor of poor prognosis.

Aged↗
PubMed1995

[Long-term results of surgical treatment for renal pelvic and ureteral tumors].

Fifty eight cases of primary tumors in the renal pelvis and ureter were treated at Toranomon Hospital between 1983 and 1992. They consisted of 32 renal pelvic tumors, 21 ureteral tumors and 5 tumors at both sites. The age of the patients ranged from 30 to 84 years (mean 63.1). Surgery was performed in 56 cases. Radical nephroureterectomy with concomitant ipsilateral retroperitoneal lymph node dissection was performed in 38 cases. The other surgeries were radical nephroureterectomy without lymph node dissection in 9, nephrectomy in 4, resection of ureter and reanastomosis in 3, radical nephroureterectomy and cystectomy in 1 and partial nephrectomy in 1. Pathologically, 53 were transitional cell carcinoma (TCC), 2 were TCC plus squamous cell carcinoma and 1 was TCC plus adenocarcinoma. Over-all survival rates (Kaplan-Meier) of 56 surgical cases at 1, 3, 5 years were 92.2, 83.7 and 72.8%, respectively. Combination chemotherapy (M-VAC or CAP) was performed in 9 cases of metastatic disease and 1 case of bilateral disease. Of these 10 cases, one achieved complete remission, 2 no change and 7 had progressive disease. Adjuvant chemotherapy was performed in 21 cases after surgery. These 21 patients were of high risk in recurrence either Grade 3 or pT3. However, the 5-year survival rate was 77.3% in these patients. Thus we conclude that the adjuvant chemotherapy in high risk patients was effective in our cases.

Adult↗
PubMed1994

Frequent loss of heterozygosity of the long arm of chromosome 7 is closely associated with progression of human gastric carcinomas.

Loss of heterozygosity (LOH) on the long arm of chromosome 7 was examined using 5 polymorphic marker probes on 98 gastric carcinomas to elucidate a novel locus for development and progression of the tumors. Twenty-six (32%) of 82 informative cases showed LOH on 7q on at least one locus of 5 loci. Among 5 loci, LOH at D7S95 locus was most frequent, the incidence being 53% in well-differentiated gastric carcinomas and 33% in poorly differentiated and scirrhous gastric carcinomas respectively. At 3 loci, c-met, D7S63 and D7S22, the incidence of LOH was about 30% and 10% in well-differentiated and poorly differentiated gastric carcinoma cases respectively. In contrast, LOH at D7S64 was not detected in any gastric-carcinoma cases. Deletion mapping of 7q revealed that D7S95 locus was the essential region of LOH. Eight (62%) of 13 cases with LOH at D7S95 locus belonged to the most advanced stage grouping. Furthermore, 6 (75%) of 8 cases with abdominal dissemination showed LOH at D7S95. Therefore, cases with LOH at D7S95 showed significantly worse prognosis than the cases without the LOH in the stage-III and stage-IV groups. These findings overall suggest that D7S95 locus on 7q may contain a candidate suppressor gene for the progression of gastric carcinoma.

Adenocarcinoma↗
PubMed1994

[Endourologic treatment of the upper urinary tract obstruction in the advanced cancer patients].

88 cancer patients with an upper urinary tract obstruction were endourologically treated. The obstructions were caused by metastasis or invasion of cancer in all patients. First we tried to insert a ureteral stent catheter (STENT). When it failed percutaneous nephrostomy (PCN) was performed. Initially 69 and 19 patients were treated by STENT and PCN, respectively. Of 69 patients with STENT, 13 received PCN later. The average survival of all patients after treatment was 5.7 months. About 60% of the patients were discharged from hospital. The patients treated by STENT and PCN survived for 5.4 months and 6.7 months in average. The STENT was changed 1.8 times on the average in all patients. 79% of the patients who had been treated by STENT experienced only one or two times of STENT changes before dying. Patency period of inserted STENT was studied. On the average the STENT occluded after 72.4 days. The patent period of STENT was longer in the patients group of prophylactic STENT insertion for hydronephrosis. The period was shorter in the patients who showed gross hematuria at the time of surgery. Patent period of STENT was not related to STENT size. Although survival was not so long, over 60% of the patients were able to return to their homes. Endourologic treatment of urinary obstruction was performed in only 6 patients in 1985. The number of such cases has been increasing gradually and currently 20 patients are treated annually. It is supposed that there are many more cancer patients with urinary tract obstruction in their end-stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Efficacy of the "Gen-Probe Mycobacterium Tuberculosis Direct Test (MTD)" for detection of Mycobacterium tuberculosis in clinical specimens--comparison between the MTD and the test by culture on Ogawa's egg medium or in the MB Check System].

Three or more weeks are usually required for detecting Mycobacterium tuberculosis by the known culture methods, and therefore, the development of a rapid bacteriological diagnostic method for M. tuberculosis has been urgently awaited. Recently, Gen-Probe Inc. has developed the "Gen-Probe Mycobacterium Tuberculosis Direct Test (MTD)", which is based on amplification of the ribosomal RNA (rRNA) of M. tuberculosis in clinical specimens and hybridization of the amplified rRNA with a M. tuberculosis-specific DNA probe, as a rapid direct diagnostic method for tuberculosis. We therefore compared the sensitivity and specificity of the MTD in detecting M. tuberculosis with the culture methods on Ogawa's egg medium and in the MB Check System, using 107 clinical specimens as test material. The results obtained are as follows: 1. Of the 61 clinical specimens which were negative when cultured on Ogawa's egg medium, 13 (21.3%) were positive for M. tuberculosis using the MTD, and of the 48 clinical specimens which were negative when cultured in the MB Check System, 8 specimens (16.7%) were positive for M. tuberculosis using the MTD. 2. All of the specimens which yielded growth of M. tuberculosis (identified by the DNA probe) either on Ogawa's egg medium or in the MB Check System, except one, were positive for M. tuberculosis in the MTD. The only one exception was a specimen which was positive for M. tuberculosis in both Ogawa's medium and the MB Check System.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[A comparative study on the serum and tissue 5-FU concentrations in patients with hepatocellular carcinoma after preoperative oral administration of UFT and 5'-DFUR].

UFT or 5'-DFUR was orally administered to the patients with hepatocellular carcinoma preoperatively and the concentrations of these drugs and 5-FU in the serum, liver tissue and cancer tissue obtained at the time of operation were measured. The unchanged 5'-DFUR was not detected in any of these samples. The concentration of 5-FU in cancer tissue was significantly higher in UFT treated group (0.409 microgram/g) than that in 5'-DFUR group (0.040 microgram/g). However, the 5-FU levels in the serum and noncancerous liver tissue were also higher than those in the patients with other organ cancers. Although UFT is a useful drug for the adjuvant chemotherapy of hepatocellular carcinoma, the dose was considered to be minimized to avoid the side effects since the activity of drug-metabolizing enzymes may be decreased in hepatocellular carcinoma complicated with liver cirrhosis.

Administration, Oral↗
PubMed1993

[Optical density of human macular pigment in spectral sensitivity measurements].

Optical density of the human macular pigment was measured by studying the spectral sensitivities to 1 degree, 200 ms test flashes on a 430 nm monochromatic background in the fovea and 10 degrees outside the fovea. Narrow-band (6 to 10 nm half band width) interference filters were used for the test lights. The difference between the spectral sensitivity in the fovea and outside the fovea coincided with the optical density of the macular pigment estimated previously by psychophysical means. We suggest that this method is useful for investigating the optical density of human macular pigment.

Adult↗
PubMed1993

Occurrence of sequential intraocular tumors: malignant medulloepithelioma subsequent to retinoblastoma.

A 13-year-old boy, whose bilateral retinoblastoma had been treated by enucleation (OD) and irradiation (OS), developed anterior staphyloma (OS) necessitating the second enucleation. Histopathological, immunohistochemical and electron microscopic studies revealed malignant teratoid medulloepithelioma of the ciliary body, with demonstrated multipotential histogenesis. This is the first report which demonstrates the development of a second malignant intraocular tumor in an eye previously affected by hereditary retinoblastoma. Careful monitoring of patients who have had hereditary retinoblastoma is necessary because of the potential for a second malignancy.

Adolescent↗