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Biomedical subjects

T Sano

Publications and source records attributed to T Sano.

At least 253 records · Page 14Linked to original sources

Microradiographic and microscopic investigation of a rare case of complex odontoma.

An extremely rare case of odontoma that erupted into the oral cavity is presented. The lesion was surgically removed from a 14-year-old girl and examined by soft x-ray radiography, microradiography, and microscopy to determine whether the lesion was complex or compound. Macroscopically, the surface of the lesion was slightly lobular and solid, resembling the surface of an osteoma. The soft x-ray radiograph obtained from the surgical specimen showed radially arranged radiopaque spicules. Microradiographically, dentin was shown to be present in relatively large quantities and to form the bulk of the tumor, with irregular enamel and cementum in small quantities. There were numerous, comparatively well-formed, enamel-free, toothlike structures in the peripheral region of the tumor. Microscopically, the toothlike structures were seen to be arranged radially; this corresponded to the microradiographic findings. Each structure consisted of a central core of pulp tissue encased in a shell of dentin. In the central area of the mass, there was an irregular conglomerate of dentin, enamel, cementum, and pulp tissue. The findings showed that the lesion was a complex odontoma.

Adolescent↗

A photodetoxification mechanism of the cyanobacterial hepatotoxin microcystin-LR by ultraviolet irradiation.

When microcystin-LR was exposed to UV, three major nontoxic compounds were formed. These compounds were identified as [4(E),6(Z)-Adda5]- and [4(Z),6(E)-Adda5]microcystin-LR, which are geometrical isomers of the Adda [3-amino-9-methoxy-2,6,8-trimethyl-10-phenyl-4(E),6(E)-decadienoic acid] moiety of microcystin-LR, and a novel compound, tricyclo-Adda [(2S,3S,1'R,3'S,4'S,5'R,6'R,7'R)-3-amino-5-(4',6'-dimethyl-3'-methoxy tricyclo[5.4.0.0(1',5')]undeca-8',10'-dien-6'-yl)-2-methy l-4(E)-pentenoic acid]-containing microcystin-LR ([tricyclo-Adda5]microcystin-LR), which was formed by [2 + 2] addition between the benzene ring and the double bond at position 6-7 of the Adda moiety of the microcystin. The geometrical isomers were formed reversibly, and their equilibrium constants were almost the same. [Tricyclo-Adda5]microcystin-LR was also formed reversibly and was decomposed under UV light. These results suggest that the breakdown of microcystin-LR by UV irradiation proceeds via [tricyclo-Adda5]microcystin-LR.

Animals↗

Telomerase activity in 144 brain tumours.

Unlimited proliferation in immortalized cells is believed to be highly dependent on the activity of telomerase, a ribonucleoprotein that synthesizes telomeric repeats onto chromosome ends. Using a polymerase chain reaction-based telomeric repeat amplification protocol (TRAP) assay, we analysed telomerase activity in 99 benign and 45 malignant brain tumours. The TRAP assay results were quantitated by normalizing the telomerase activity of each specimen to that of human glioma cell line T98G to obtain the relative telomerase activity. Telomerase activity was also assessed visually from the autoradiograms as being positive or negative. One hundred and sixteen tumours with negative telomerase activity had null relative telomerase activity, whereas 28 tumours with positive telomerase activity had relative telomerase activities of 12-84.3% (mean 0% vs 36.1 +/- 19.3%, P < 0.0001). Thus, quantification of telomerase activity confirmed the results of the visual evaluation of telomerase activity on autoradiograms. Based on the assessment, malignant brain tumours had a higher positive rate of telomerase activity than benign tumours (57.8% vs 2.0%, P < 0.001). These data indicate that positive telomerase activity is strongly associated with malignant brain tumours and is rather rare in benign tumours, such as neurinomas or meningiomas.

Brain Neoplasms↗

Familial isolated primary hyperparathyroidism with parathyroid carcinomas: clinical and molecular features.

OBJECTIVE: Familial isolated primary hyperparathyroidism (FIHP) is a rare hereditary disorder. We present four patients from a single family with FIHP, and genetic analysis of their parathyroid adenomas and parathyroid carcinoma. DESIGN: DNA was extracted from tumours resected at surgery. Tumours were examined for loss of heterozygosity (LOH) with microsatellite polymorphic markers. PATIENTS: The 27-year-old proband (Patient 1) died of parathyroid carcinoma with metastases to the lungs and chest wall. Sixteen years later, his 34-year-old sister (Patient 2) presented with a neck tumour and primary hyperparathyroidism. Family screening revealed parathyroid tumours in his 36-year-old sister (Patient 3) and 29-year-old cousin (Patient 4). Histological examination of resected tumours showed parathyroid carcinoma and adenoma in Patient 2, a parathyroid adenoma in Patient 3, and an atypical parathyroid adenoma in Patient 4. Autopsy of the proband ruled out multiple endocrine neoplasia (MEN) type 1, and the three patients who underwent parathyroidectomy did not exhibit any abnormalities in the pancreas or the pituitary gland. RESULTS: Analysis of tumour DNA from one parathyroid carcinoma (Patient 2), the atypical parathyroid adenoma (Patient 4), and two parathyroid adenomas (Patients 2 and 3) showed limited LOH on chromosomes 13q12.3-q32 in an adenoma of Patient 2 and 9p21-p22 and 13q12.3-q32 in an adenoma of Patient 3. CONCLUSION: These results suggest the possible contribution of tumour suppressor genes including the retinoblastoma gene and the hereditary breast cancer susceptibility gene (BRCA2) on 13q to parathyroid tumours in this family.

Adenoma↗

Immunohistochemical analysis of Ki-67 antigen and Bcl-2 protein expression in prostate cancer: effect of neoadjuvant hormonal therapy.

OBJECTIVE: To determine differences in the immunohistochemical (IHC) expression of Bcl-2 protein and Ki-67 antigen in patients with prostatic cancer who underwent radical prostatectomy with or without neoadjuvant hormonal therapy. MATERIALS AND METHODS: Ki-67 antigen and Bcl-2 protein were detected by IHC using MIB-1 and Bcl-2 antibodies in prostatectomy specimens from 28 patients who received hormonal therapy before surgery (group 1) and 51 patients who did not (group 2). RESULTS: In group 2, the mean MIB-1 index increased with increasing grade of tumour, from 11.6% in low-grade to 24.7% in high-grade tumours (P = 0.002). Bcl-2 expression did not correlate with either tumour grade or stage. In group 1, there were no correlations between Bcl-2 expression or MIB-1 index and tumour grade or stage. More tumours in group 1 were Bcl-2-positive (16 of 28, 57%) than were tumours in group 2 (11 of 51, 22%; P = 0.003). The mean (SD) MIB-1 index of tumours in group 2 [15.6 (14.4)%], was significantly greater than that of tumours in group 2 [6.8 (7.5)%; P = 0.004]. CONCLUSIONS: These results indicate that Bcl-2 positivity is increased by androgen ablation therapy and conversely, that the proliferative activity of cancer cells is significantly reduced. The expression of Bcl-2 protein may play a role in the ability of prostate cancer cells to survive in an androgen-deprived environment.

Aged↗

The outcome of surgical treatment for gastric carcinoma in the elderly.

Surgeons are increasingly being faced with the problem of treating elderly gastric carcinoma patients. The purpose of this study was to elucidate the feasibility of surgical treatment for these patients. Among 4740 gastric carcinoma patients treated from 1971 to 1990, 112 (2.4%) were aged 80 or over. The results of treatment in this elderly group were compared retrospectively with those in 2664 younger gastric carcinoma patients (aged 50-69, control group, 56.2%). The TNM stage distribution and the curative resection rates (75.9 vs 81.4%) were similar between the groups. Reduced nodal dissection was more common in the elderly group. The elderly had a higher incidence of preoperative risk factors (76.8 vs 53.1%) and 90-day mortality (10.7 vs 3.9%). However, the postoperative complication rates were similar between the groups. The 90-day mortality rates in the elderly group were higher in the subgroups undergoing total gastrectomy or D2 dissection. In the patients without pre-existing morbidity, the 30-day mortality, 90-day mortality and postoperative complications were similar between the groups. The 5-year survival rate after curative resection of the elderly group was significantly lower than that of the control group (44.4 vs 74.0%). This difference lost significance when non-cancer death was excluded (62.5 vs 79.9%). We believe that, although gastrectomy can be carried out safely in elderly patients, extended surgery should be limited to those without preoperative morbidity.

Aged↗

Frequent expression of bcl-2 protein in solitary fibrous tumors.

The distinction of solitary fibrous tumors from histologically similar neoplasms is often difficult because they rarely occur at a variety of extrapleural sites. CD34 immunoreactivity has recently been recognized to be an adjunct for the diagnosis of solitary fibrous tumors. However, it is now known that CD34 staining is not entirely specific for this entity. We evaluated 23 solitary fibrous tumors and 54 other spindle cell tumors often considered in the differential diagnosis for immunoreactivity using monoclonal antibodies directed against bcl-2 protein, which protects cells from apoptosis and CD34. The patients with solitary fibrous tumors comprised 11 men and 12 women, ranging in age from 35 to 85 years (mean, 57.6 years). Fourteen tumors arose in the pleura, four in the retroperitoneum, three in the superficial soft tissue and one each in the mediastinum and uterine cervix. Nineteen of 23 solitary fibrous tumors (83%), irrespective of tumor site, demonstrated diffuse cytoplasmic staining for bcl-2 protein. bcl-2 immunoreactivity was also observed in five of seven neurofibromas (71%), eight of 10 synovial sarcomas (80%) and one of three spindle cell lipomas (33%). CD34 immunoreactivity was present in all but one solitary fibrous tumor (96%), seven of seven neurofibromas (100%), three of three spindle cell lipomas (100%), five of five dermatofibrosarcomas (100%), three of three hemangiopericytomas (100%) and two of seven malignant fibrous histiocytomas (29%). To date, most of the pleural and extrapleural cases have not shown aggressive features. We suggest that bcl-2 protein can be used together with CD34 in the diagnosis of solitary fibrous tumor to distinguish this entity from other spindle cell neoplasms.

Adult↗

Primary liposarcoma of the stomach: a case report and a review of the literature.

Primary liposarcoma of the stomach is rare and only seven cases have been described in the English literature. Here we report the eighth case, which occurred in a 68-year-old woman who presented with repeated tarry stools and hematemesis. Endoscopic examination revealed a large ulcerated submucosal mass at the gastric angle. The patient was treated by total gastrectomy. On microscopic examination, the tumor showed the features of a well differentiated sclerosing liposarcoma. Immunohistochemically, many spindle to stellate tumor cells were diffusely positive for vimentin and CD34. Positivity for S-100 protein was found in the adipocytic component, including lipoblasts, in addition to some spindle-shaped tumor cells. On ultrastructural examination, the spindle to stellate cells had features characteristic of fibroblasts. No recurrence or metastasis was seen during 13 months. Liposarcoma of the stomach has to be considered in the differential diagnosis with other submucosal lesions, such as gastric lipoma and gastrointestinal stromal tumor.

Aged↗

True calcium absorption in the intestine is enhanced by fructooligosaccharide feeding in rats.

Fructooligosaccharides (FOS) have been shown to stimulate apparent calcium absorption in the intestine. In this study, we examined the effect of FOS on true calcium absorption using the calcium balance in combination with the 45Ca kinetics method. Sixteen 45-d-old male Wistar rats were randomly divided into two groups, a control group (n = 8) and a FOS group (n = 8). The diet fed to the FOS group contained 5% FOS, at the expense of half of the sucrose in the control diet. After an adaptation period (3 d) and a free-access period (3 d) that were used to estimate the amount of food required for pair-feeding on the basis of calcium, all of the rats were pair-fed throughout the experiment from the age of 51 d. A constant amount of calcium was fed to the rats in each group (95 mg /d). At age 60 d, a 3-d metabolic study was started by the intravenous injection of 45Ca. Several variables were calculated on the bases of measurements of calcium intake, calcium in feces and serum, and 45Ca in feces, urine and serum. Both true and apparent calcium absorption in the intestine (Vad and Vna) and urinary calcium were significantly greater in rats that had been fed FOS. There were no differences between the groups in endogenous net calcium excretion into feces (Vf; Vad - Vna). The calcium balance was also enhanced by FOS. Calcium balance in the FOS group was significantly correlated with the absorbed calcium (r2 = 0.936, P < 0.01), as was that in the control group (r2 = 0.994, P < 0.01). These results suggest that the increased true calcium absorption and balance produced by FOS feeding might improve bone calcification.

Animals↗

Spherulitic brushite stone in the dental pulp of a cow.

Pulp stones of human teeth usually contain biological apatite. In the dental pulp of a cow, aged 12 years, we observed spherulitic pulp stones, up to approximately 200 microns in diameter, consisting of radially arranged crystals with several kinds of light microscopy and scanning electron microscopy including the secondary electron and the backscattered electron signals. The crystals extending fan-like towards the periphery showed a rectangular shape, and they had subunits of elongated crystallites and fine slits of NaOCl-dissolved substances, probably including organic matter and amorphous mineral. By using energy-dispersive X-ray microanalysis, large amounts of Ca and P, and trace elements of Na, Mg, Cl, and Fe were detected from the stones. The calcium phosphate crystals were identified as biological brushite by shape, Ca/ P molar ratio, and electron diffraction pattern. Core regions of the stones containing granular structures, probably erythrocytes, were always present in blood vessels, and rectangular crystals frequently penetrated the vessel walls. Under the decalcified sections, the nidi were completely or incompletely dissolved, but the peripheries showed a radial arrangement of erythrocytes. Thus, the nidi may be thrombus or necrotic blood cells including erythrocytes. Such calcospherulites in the dental pulp of a cow were similar to the spherulitic pulp stones in human deciduous teeth reported previously, however, their nidi were present in different regions.

Animals↗

Second primary rhabdomyosarcomas in patients with bilateral retinoblastoma: a clinicopathologic and immunohistochemical study.

We reviewed six cases of rhabdomyosarcoma as a rare second primary malignancy in children with bilateral retinoblastoma after irradiation treatment. The patients comprised four females and two males (age range 1 year 4 months-7 years 11 months). Second tumors arose in the temporal muscle inside or close to the previously irradiated fields. All the children were alive and well 24-72 months after diagnosis. Microscopic examination showed proliferation of closely packed, small round cells with scanty cytoplasm, coarse nuclear chromatin, and increased mitotic activity without a myxoid background nor obvious alveolar architecture. The most characteristic feature was the presence of rosette-like structures in four tumors. Immunoreactivity for many skeletal muscle markers was evident, including desmin (six of six), muscle-specific actin (HHF35) (six of six), sarcomeric actin (six of six), myogenin (six of six), vimentin (six of six), and myoglobin (three of six). On reverse transcriptase-polymerase chain reaction examination, three second tumors lacked specific chimeric transcripts for alveolar rhabdomyosarcoma and Ewing's sarcoma. Unexpectedly, variable reactivity for neurofilament (150 kd) was identified in six of six second tumors as well as 15 of 20 sporadic primary rhabdomyosarcomas (75%) examined as controls, the result being confirmed by Western blot analysis. In addition, staining for retinoblastoma-susceptibility gene protein was negative in all second tumors, in contrast to positivity in 14 of 17 sporadic primary tumors (82%). This finding suggests that retinoblastoma-susceptibility gene abnormalities could be associated with the development of second primary rhabdomyosarcoma. We consider that knowledge of the occurrence of rhabdomyosarcoma and appropriate immunohistochemical study are helpful for avoiding a misdiagnosis of recurrent retinoblastoma or Ewing's sarcoma when encountering patients with a history of bilateral retinoblastoma who developed second small round cell neoplasms.

Antigens, Neoplasm↗

Perineurial malignant peripheral nerve sheath tumor (MPNST): a clinicopathologic, immunohistochemical, and ultrastructural study of seven cases.

Most malignant peripheral nerve sheath tumors (MPNST) are schwannian in nature. The pathologic features of MPNST with perineurial cell differentiation remain to be characterized. To determine the clinicopathologic, immunohistochemical, and ultrastructural characteristics of perineurial MPNST, 121 MPNST from the Mayo Clinic Tissue Registry were examined. Of these 23 spindle cell tumors with long processes disposed in whorls or storiform patterns, features typical of perineurioma, were studied. On the basis of immunohistochemistry (epithelial membrane antigen+/S-100-), 5 perineurial MPNST were identified among 23 tumors selected. These and two previously characterized perineurial MPNST are the subject of this study. None of seven tumors was associated with NF-1. Patients included five males and two females ranging in age from 11 to 83 years (mean, 45.7 years). The tumors measured 1.5 to 30 cm (mean, 9.1 cm) and arose in the extremities (two), trunk (two), face (one), mediastinum (one), and retroperitoneum (one). Only one tumor was nerve associated (phrenic nerve). All tumors were surgically removed. No encapsulation or neurofibroma components were noted. Necrosis was seen in three lesions. Four tumors were classified as high-grade malignant and three as low grade. Mitotic indices varied from 1 to 85/10 high-power fields (median, 16). Immunoreactivities included epithelial membrane antigen (100%), vimentin (100%), Leu-7 (57%), and CD34 (14%). Stains for S-100 protein, muscle markers, and cytokeratin were nonreactive. Ultrastructurally, perineurial-like cells were noted in three tumors and cells intermediate between perineurial and Schwann cells in one. Four tumors recurred and two metastasized; no deaths of disease were noted at follow-ups of 28 to 98 months (mean, 66.9). In conclusion, 4% of MPNST show perineurial cell differentiation. An NF-1 association has yet to be described. Nerve involvement is infrequent. Their immunophenotype (epithelial membrane antigen+/S-100-) frequently indicates ultrastructural perineurial differentiation. The prognosis of perineural MPNST appears to be more favorable than that of conventional MPNST.

Adult↗

Coexpression of HGF and c-Met/HGF receptor in human bone and soft tissue tumors.

To understand the interaction between hepatocyte growth factor (HGF) and its receptor c-Met on various bone and soft tissue tumors, their expressions were investigated by western blot analysis, immunohistochemistry and enzyme immunoassay. Western blot analysis revealed that c-Met protein was expressed in 21 (38.8%) of 54 tumors, which detailed to seven (25.9%) of 27 bone tumors and 14 (51.8%) of 27 soft tissue tumors. Most malignant fibrous histiocytomas (MFH) and all neurofibromas expressed c-Met protein. The highest expression of c-Met protein was seen in a case of biphasic synovial sarcoma, where its immunoreactivity was localized only on the epithelial component and not on the sarcomatous component. By enzyme immunoassay for HGF, all but one MFH showed HGF production and the mean level of HGF was the highest among the tumors investigated. Neurofibromas and osteosarcomas had the next highest mean levels of HGF production, respectively. Coexpression of HGF and c-Met was observed in 19 (35.2%) of 54 tumors and was frequently observed in neurofibroma, followed by MFH and synovial sarcoma. Although the mode of interaction between HGF and c-Met varies among the various bone and soft tissue tumors including MFH, their signaling system may play an important role in the development and progression of bone and soft tissue tumors.

Blotting, Western↗

c-Met expression of thyroid tissue with special reference to papillary carcinoma.

It has become clear that papillary carcinomas of the thyroid often express the receptor for c-Met/hepatocyte growth factor (HGF) receptor, but little is known about the role of the HGF and c-Met system in the pathogenesis of thyroid carcinoma. In this study, the expression of c-Met/HGF receptor was evaluated in thyroid tissue by western blot and immunohistochemistry, and compared with the concentration of HGF. Clinicopathological characteristics were also compared. Fifteen of 20 papillary carcinomas (75%) showed c-Met bands of 145 kDa. No or only a low frequency of c-Met expression was detected in healthy thyroid tissue (0/5), thyroiditis or Basedow's disease (0/2), adenomatous goiters (0/8), follicular adenomas (1/9, 11%) and undifferentiated carcinomas (0/2). These results were confirmed by immunohistochemistry, but a relatively higher frequency of c-Met expression was detected in adenomatous goiters (25%), follicular adenoma (44%) and papillary carcinoma (100%) using formalin-fixed and paraffin-embedded materials. A strong immunoreaction for c-Met was observed in the tumor cytoplasm of papillary carcinomas among the fibrous tissues situated at the periphery of the tumor. The densitometrically measured expression of c-Met had no relation to tumor stage in papillary carcinoma, but did correlate to the concentration of HGF in papillary carcinomas. In conclusion, in thyroid lesions, c-Met was highly expressed specifically in the cytoplasm of papillary carcinomas. c-Met expression was not related to the aggressiveness of the tumor but was related to the concentration of HGF, which was probably derived from the stroma. Also, the c-Met system might play a role in the pathogenesis of papillary carcinoma of the thyroid.

Adenoma↗

Immunohistochemical overexpression of p16 protein associated with intact retinoblastoma protein expression in cervical cancer and cervical intraepithelial neoplasia.

Both p16 and retinoblastoma (Rb) proteins are important tumor suppressors that regulate the cell cycle. The status of both proteins in invasive cervical cancer and cervical intraepithelial neoplasia (CIN) has not yet been examined. The aim of this study was to investigate the expression of p16 and Rb proteins by immunohistochemistry using 98 formalin-fixed and paraffin-embedded samples of various cervical neoplastic lesions. Strong immunoreactivity for the p16 protein was observed in both the nuclei and cytoplasm of all CIN and invasive cancer cases except several low-grade CIN lesions. Expression of Rb protein was also demonstrated in the scattered nuclei of neoplastic and normal cells in all cases investigated. The results suggest that the deletion or mutational inactivity of both p16 and Rb proteins may be a rare event in cervical carcinogenesis. Moreover, overexpression of the p16 protein may be a useful diagnostic marker for cervical neoplastic lesions on routine laboratory screening.

Adenocarcinoma↗

Gliosarcoma: an immunohistochemical, ultrastructural and fluorescence in situ hybridization study.

Three cases of primary gliosarcoma (GS) were studied by immunohistochemical, ultrastructural and fluorescence in situ hybridization (FISH) methods. All tumors occurred in the supratentorial regions of the body. No patient had a prior history of irradiation to the brain. All patients died of tumor within 1 year, and autopsies were performed in two cases. Microscopically, each of the three tumors showed a mixture of glioblastoma (GBM) and a sarcomatous component (SC), which resembled fibrosarcoma with various histological features. Numerous collagen and reticulin fibers were seen in the SC of all tumors. Glial fibrillary acidic protein (GFAP) was immunoreactive only in the gliomatous component (GC). Factor VIII-related antigen was negative except for endothelial cells. One tumor exhibited alpha-smooth muscle actin positivity in the SC. Expression of MIB-1 and p53 protein was demonstrated in both components for all tumors. Labeling indices (LI) for MIB-1 ranged from 7.7 to 36.1%, and LI for p53 protein ranged from 2.9 to 57.0%. Ultrastructurally, astrocytic cells were characterized by a polygonal configuration with many cytoplasmic projections and occasional filaments. Spindle-shaped fibroblasts in the SC contained well-developed rough endoplasmic reticulum. Fluorescence in situ hybridization (FISH) performed on fresh materials or paraffin-embedded tissue demonstrated single signals for chromosome 10 in 40.6-58.3% of cells and for chromosome 17 in 37.9-48.6% of cells. Two tumors were regarded as containing losses of both chromosomes 10 and 17, while the third showed a substantial loss only of chromosome 10. As similar aberrations have been reported in GBM, these chromosomal abnormalities suggest a common pathogenesis in GS and GBM.

Actins↗

Transitional cell papilloma in the fossa navicularis is positive for human papillomavirus.

Transitional cell papillomas rarely develop in the fossa navicularis of the anterior urethra. We observed such a case of transitional cell papilloma and detected human papillomavirus type 6 (HPV-6) DNA in this papilloma by polymerase chain reaction. To our knowledge this report is the first of HPV-infected transitional papilloma in the anterior urethra.

DNA, Viral↗