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T Aihara

Publications and source records attributed to T Aihara.

At least 19 recordsLinked to original sources
PubMed1998

Previously undescribed spondyloepiphyseal dysplasia associated with craniosynostosis, cataracts, cleft palate, and mental retardation: report of four sibs.

We report on four Japanese sibs (three brothers and one sister) with a previously unreported syndrome of spondyloepiphyseal dysplasia, craniosynostosis, cataracts, cleft palate, and mental retardation. Most clinical manifestations were evident neonatally, but skeletal changes and cataracts became substantial in early childhood. Radiological anomalies comprised coronal synostosis, mild epiphyseal dysplasia, particularly in the distal tibiae, strikingly delayed patellar ossification, mild metaphyseal splaying, hypoplastic ilia with iliac flare, and platyspondyly with ovoid-shaped or posteriorly humped vertebral bodies. The nonconsanguineous parents were mildly mentally retarded, and sibs of both gender were equally affected; thus, inheritance was likely autosomal recessive.

Abnormalities, Multiple↗
PubMed1998

A distinct subtype of "metatropic dysplasia variant" characterised by advanced carpal skeletal age and subluxation of the radial heads.

BACKGROUND: "Metatropic dysplasia variants" are a group of bone dysplasias whose skeletal abnormalities are similar to, but milder than, those of classical metatropic dysplasia. The genetic and phenotypic heterogeneity has not been thoroughly elucidated. OBJECTIVE: The objective was to designate a distinct subtype of these metatropic dysplasia variants. MATERIALS AND METHODS: The subjects were four Japanese patients, two sporadic cases and two siblings, who all had identical skeletal changes. The radiological features in these patients were compared with those of previously reported metatropic dysplasia variants. RESULTS: Moderate platyspondyly with pear-shaped and/or anterior-tongued vertebral bodies, halberd pelvis, and dumbbell deformity of the tubular bones were regarded as hallmarks of metatropic dysplasia variants. The peculiar skeletal change in our patients was advanced carpal skeletal age in childhood, unlike most patients reported as metatropic dysplasia variants who manifest delayed carpal ossification. Another hallmark was congenital dislocation of the radial heads. A description of a patient with similar skeletal changes was found in the literature. CONCLUSION: These patients are considered to represent a distinct subgroup of metatropic dysplasia variants. It remains unknown whether the present siblings represent an autosomal recessive trait or an autosomal dominant trait with germinal mosaicism related to increased paternal age.

Abnormalities, Multiple↗
PubMed1998

Spontaneous regression of localized neuroblastoma detected by mass screening.

PURPOSE: To clarify whether and when neuroblastomas identified through screening do regress, and to ascertain how to treat them appropriately, we observed screened patients who had localized tumors, without any therapeutic intervention. PATIENTS AND METHODS: The criteria for the observation program were as follows: disease stage I or II; tumor less than 5 cm in diameter; no invasion to the intraspinal canal or growth to the great vessels; urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA) less than 50 microg/mg creatinine; and informed consent. Of 25 patients identified through screening for 6-month-old infants in Saitama Prefecture, Japan between April 1994 and March 1996, 11 patients who met the criteria and one other patient with stage III tumor were enrolled onto the program. They were examined by abdominal ultrasonography (US) and their urinary VMA and HVA levels were assessed approximately once per month. The observation periods ranged from 4 to 27 months. RESULTS: The 11 tumors decreased in size, although one of these 11 tumors initially enlarged until the patient was 12 months of age and decreased in size thereafter. One other tumor slightly increased in size. Urinary VMA levels decreased in all patients. None of the tumors had completely disappeared by the last observation day. CONCLUSION: Our results suggest that regression of screened neuroblastoma is not a rare phenomenon. At present, it seems reasonable to adopt a wait-and-see strategy, with careful observation, for selected stage I or II tumors identified in infants screened at 6 months of age.

Homovanillic Acid↗
PubMed1997

Detection of pancreatic and gastric cancer cells in peripheral and portal blood by amplification of keratin 19 mRNA with reverse transcriptase-polymerase chain reaction.

Reverse transcriptase-polymerase chain reaction (RT-PCR) targeted at keratin 19 mRNA was applied to detect circulating cancer cells in the peripheral and portal blood of pancreatic and gastric cancer patients. Keratin 19 mRNA expression was studied by RT-PCR in cancer tissues (12 pancreatic and 15 gastric cancers) and in peripheral and/or portal blood samples from patients with pancreatic cancer (stage I, n = 5; stage II, n = 1; stage III, n = 15; stage IV, n = 19), gastric cancer (stage la,b, n = 28; stage II, n = 9; stage IIIa,b, n = 5; stage IVa,b, n = 7) and benign pancreatic diseases (n = 7). Peripheral blood samples from 50 healthy volunteers served as controls. RT-PCR was conducted in duplicate in each sample, and only samples showing keratin 19 transcript in both determinations were considered as being positive. All the pancreatic and gastric cancers, but none of the control blood samples, were found to be positive. Dilution study using pancreatic cancer cells serially mixed against peripheral blood showed that detection sensitivity was more than one cancer cell in 10(6) peripheral blood mononuclear cells. In pancreatic cancer patients, RT-PCR analysis of the portal blood samples gave positive results in one stage III and one stage IV patient, and that of peripheral blood samples gave positive results in 2 stage IV patients. No positive results were obtained in any of the blood samples from gastric cancer patients. Our results indicate that incidence of circulating cancer cells is unexpectedly very low even in advanced pancreatic and gastric cancer patients.

Humans↗
PubMed1997

Stimulus-dependent induction of long-term potentiation in CA1 area of the hippocampus: experiment and model.

In the CA1 area of the hippocampus, the magnitude of long-term potentiation (LTP) depends not only on the frequency of applied stimuli, but also on their number. With a slice preparation using extracellular recording in the hippocampus CA1 of a guinea pig, we investigate the magnitude of LTP induced by electrical stimuli with a range of frequencies and the number of applied stimuli. We find that the magnitude of the saturated potentiation obtained with periodic stimuli largely depends on the frequency and is insensitive to the number of stimuli, once the saturation level has been obtained. Furthermore, we investigated nonperiodic stimuli and found that the magnitude of the saturated potentiation is also sensitive to the statistical correlation between successive interstimulus intervals, even when their average frequency is held constant. In order to explain the LTP dependence on these various experimental parameters, we propose a simple mathematical model for the induction of LTP. In the model, an exponentially decaying element released as a result of previous stimuli is coupled with a new stimulus to act as the potentiation force, and the magnitude of potentiation is determined by this potentiation force. We can determine the decaying time constant of this hypothetical element as a model parameter by fitting the model to the experimental data. The time scale is found to be of the order of 200 msc. A molecular or cellular factor with this decaying time constant is likely to be induced in LTP induction.

Animals↗
PubMed1997

The production and clearance of endothelin and its influence on kidney function after liver transplantation in rats.

To assess the involvement of endothelin-1 (ET-1) in rat liver allograft rejection, we evaluated ET-1 expression in tissues obtained from BN (RT1n) to BN rats (group 1), and DA (RT1a) to BN rats (group 2). The ET-1 levels in group 1, determined by radioimmunoassay, remained low in the serum, liver, and bile, but in group 2, they peaked on postoperative day (POD) 5 in the liver, kidney, bile, and urine, at 344 +/- 31.6 pg/gwet, 306 +/- 97.4 pg/gwet, 1008 +/- 258 pg/day, and 156 +/- 45 pg/day, respectively, whereas levels in the serum peaked on POD 7 at 38.7 +/- 13.1 pg/ml. In the portal vein (PV) ET-1 showed extremely high levels without statistical difference between groups 1 and 2, at 93.0 +/- 15.5, and 83.0 +/- 9.84 pg/ml on POD 7, respectively. However, in the suprahepatic vena cava (SHVC) and the abdominal aorta (AO), the ET-1 levels were statistically higher in group 2 compared to group 1 (P < 0.01). Immunohistochemical staining showed decreased staining of the liver and kidney in group 2 on POD 7. In conclusion, increasing levels of ET-1 were released from the liver and kidney during the early stage of rejection, resulting in the high ET-1 levels in these tissues, which were cleared promptly. However, an increased production of ET-1 was not observed in association with the release of ET-1.

Animals↗
PubMed1997

[Identification of predictive factors associated with recurrent restenosis after second percutaneous transluminal coronary angioplasty].

The predictive factors of a second restenosis after repeated percutaneous transluminal coronary angioplasty (PTCA) were investigated by review of the records of 100 consecutive patients who underwent second angioplasty for restenosis of the same site. PTCA was successful in 97 (97%) of these patients, but 38 patients (39%) developed a second restenosis (recurrent restenosis group) and 59 did not (no recurrent restenosis group). The clinical, angiographic and procedural factors at the second PTCA of the two groups of patients were compared. The major risk factors (hypertension, diabetes mellitus, hyperlipidemia) and type and morphology of the lesion (eccentricity, calcification, length, bend) at repeat PTCA did not differ significantly between the recurrent restenosis and no recurrent restenosis groups. The mean intervals from the initial to the second PTCA were significantly shorter in the recurrent stenosis group than in the no recurrent restenosis group (2.1 +/- 1.1 vs 3.4 +/- 1.3 months, p < 0.001). Sixteen (76%) of 21 patients had a second restenosis at an interval between the two PTCAs of < 3 months, compared with 22 (29%) of 76 patients with an interval of > or = 3 months (p < 0.001). Patients who undergo a second angioplasty procedure within 3 months from the previous procedure at the same site have a much higher risk of recurrent restenosis and these patients may benefit from an alternative therapeutic approach.

Aged↗
PubMed1996

Histologic characteristics of breast cancers with occult lymph node metastases detected by keratin 19 mRNA reverse transcriptase-polymerase chain reaction.

BACKGROUND: Amplification of keratin 19 mRNA (K19) by reverse transcriptase-polymerase chain reaction (RT-PCR) has been shown to be a sensitive method to detect occult breast cancer metastases in lymph nodes. METHODS: Axillary lymph nodes were obtained from 126 patients with breast cancer, and metastases in these lymph nodes were studied by both histologic examination and K19 RT-PCR. The patients were categorized into 3 groups according to the results of these 2 examinations, i.e., patients with 1) both histologically and K19 RT-PCR negative lymph nodes (metastases negative group [n = 91]); 2) histologically negative but K19 RT-PCR positive lymph nodes (occult metastases positive group [ n = 15]); and 3) histologically positive lymph nodes (metastases positive group [n = 20]). RESULTS: Various histologic parameters such as tumor size, histologic type, histologic grade, lymphatic invasion, vascular invasion, and estrogen receptor status were compared among these three groups. There were no significant differences among any of these histologic parameters between the metastases positive and occult metastases positive groups. Conversely, tumor size of the metastases positive (2.5 +/- 0.2 cm) and occult metastases positive (2.5 +/- 0.2 cm) groups was significantly (P < 0.05) greater than that of the metastases negative group (1.9 +/- 0.1 cm), and positivity of lymphatic vessel invasion in the former 2 groups (70% and 53%, respectively) was also significantly (P < 0.01) greater than that in the latter group (18%). CONCLUSIONS: These results demonstrate that histologic characteristics of breast cancers with occult metastases are similar to those of breast cancers with histologically detectable metastases.

Actins↗
PubMed1996

Demonstration of monoclonal origin of human parotid gland pleomorphic adenoma.

BACKGROUND: Parotid gland pleomorphic adenoma is histologically comprised of epithelial and mesenchymal elements. It remains to be established whether this neoplasm arises from epithelial and mesenchymal elements, or solely from the epithelial element. METHODS: In an attempt to resolve this issue, we have conducted clonal analysis on five pleomorphic adenomas. The method for clonal analysis was based on the trinucleotide repeat polymorphism of the x-chromosome-linked androgen receptor gene and on random inactivation of this gene by methylation. The epithelial and mesenchymal elements were obtained separately from the paraffin sections of the pleomorphic adenomas using a microdissection technique and then subjected to clonal analysis. RESULTS: Clonal analysis revealed that both epithelial and mesenchymal elements were monoclonal. In addition, the same allele of the androgen receptor gene was inactivated in both elements in every case. CONCLUSIONS: It is unlikely that the epithelial and mesenchymal elements of different origin happen to inactivate the same allele of the androgen receptor gene in all five tumors. Rather, it is more reasonable to consider that these two elements have a common single cell origin.

Adenoma, Pleomorphic↗
PubMed1996

A malignant Triton tumor in the anterior mediastinum requiring emergency surgery: report of a case.

We report herein the case of a 17-year-old woman with von Recklinghausen's disease who was diagnosed as having a giant malignant Triton tumor located in the anterior mediastinum, which had adhered to the heart and the great vessels. An emergency operation was performed to relieve the tracheobronchial stenosis and congestive heart failure caused by the pressure of the tumor. Extracorporeal circulation was not required and the tumor could be excised only piece by piece. To our knowledge, this is the first report of a malignant Triton tumor being located in the anterior mediastinum.

Adolescent↗
PubMed1996

Hypomelanosis of Ito associated with neuroblastoma.

We report a patient with hypomelanosis of Ito associated with neuroblastoma. Though not previously reported, the association is plausible since both conditions are forms of "neurocristopathy".

Adrenal Gland Neoplasms↗
PubMed1996

Venopelvic fistula: a rare complication of hyperalimentation.

The prolonged placement of a hyperalimentation catheter via the left great saphenous vein resulted in obstruction of the inferior vena cava and in the formation of a venopelvic fistula. Administration of hyperosmolar fluid via this catheter might be the cause of this complication.

Arteriovenous Fistula↗
PubMed1996

Clonal analysis of precancerous lesion of hepatocellular carcinoma.

BACKGROUND & AIMS: It remains to be established whether precancerous lesion (dysplastic nodule) of hepatocellular carcinoma (HCC) is a neoplastic or hyperplastic lesion. Clonal analysis of this lesion was conducted to elucidate this important issue on histogenesis. METHODS: The method for clonal analysis was based on restriction fragment length polymorphism of the X chromosome-linked phosphoglycerokinase gene and on random inactivation of the gene by methylation. Clonal somatic mutations were also analyzed by DNA fingerprinting with two multilocus probes (33.6 and 33.15), and loss of heterozygosity was studied using five single-locus probes (MS1[1p33-p35], MS31[7p22-pter], MS43a[12q24.3-qter], MS8[5q35-qter], and g3[7q36-qter]). RESULTS: Clonal analysis by the phosphoglycerokinase gene-based method showed that all of the five dysplastic nodules and seven HCCs were monoclonal in origin. DNA fingerprinting showed clonal somatic mutations in six of 10 dysplastic nodules and in six of nine HCCs. Loss of heterozygosity was found in one dysplastic nodule (7p22-pter) and two HCCs (1p33-p35 and 12q24.3-qter). CONCLUSIONS: These results confirm monoclonality of HCC and show that hepatic precancerous lesion (dysplastic nodule) is not a hyperplastic but a neoplastic lesion, consisting of monoclonal cells with genetic alterations.

Aged↗