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T Nitta

Publications and source records attributed to T Nitta.

At least 19 recordsLinked to original sources
PubMed2006

Interpretation of scintigraphic findings of oral malignant tumours with a new scanning agent of technetium-99m-hexakis-2-methoxy-isobutyl-isonitrile (Tc-99m-MIBI).

OBJECTIVES: The purpose of this study was to investigate the usefulness of a new scanning agent of technetium-99m-hexakis-2-methoxy-isobutyl-isonitrile (Tc-99m-MIBI) for the diagnosis of malignant tumours of the head and neck. METHODS: Scintigraphy with Tc-99m-MIBI was performed in 19 patients with malignant tumours of the head and neck. Factors of the early and delayed static scans (hot, warm or cold uptake), the early and delayed retention indexes, the blood flow index and the tumour retention index were obtained from Tc-99m-MIBI scintigraphy. Tumour retention indexes were classified into three grades; slightly (>0.9), moderately (0.9-0.8) and severely (0.8>) decreased. Grade of tissue differentiation of tumour (well, moderately or poorly differentiated) and tumour size (T1 approximately T4) were examined using the excised tumour. Scintigraphic indexes and tumour characteristics were compared. RESULTS: The early static scan and tumour size showed a correlation with the blood flow index. However, the delayed static scan did not show any relationship with blood flow index and tumour size. The tumour retention index had a tendency to decrease in malignant tumours, and showed a significant correlation with the grade of tissue differentiation of the tumour. CONCLUSIONS: The tendency of the tumour retention index to decrease in Tc-99m-MIBI scintigraphy showed the malignancy of tumour and would be useful for the diagnosis of malignant tumours of the head and neck.

Adult↗
PubMed2005

Thallium-201 chloride (Tl-201) accumulation and Na+/K+-ATPase expression in tumours of the head and neck.

OBJECTIVES: The purpose of this report was to evaluate the relationship between the tumour retention index of thallium-201 chloride (Tl-201) scintigraphy and the Na+/K+-ATPase expression in tumours of the head and neck. METHODS: Tl-201 scintigraphy was performed in 146 patients (129 with malignant tumours, ten with benign tumours and seven with inflammation). The tumour retention index was obtained from the early and delayed dynamic Tl-201 scans. The Na+/K+-ATPase expression was evaluated immunohistochemically in 61 of 129 patients with malignant tumour. Furthermore, another 22 patients with benign tumour were evaluated immunohistochemically as a benign control. Comparison of the correlations between the grade of histopathological differentiation of tumour, the tumour retention index of Tl-201 scintigraphy and the Na+/K+-ATPase expression was performed. RESULTS: The grade of histopathological differentiation of tumour, the tumour retention index of Tl-201 scintigraphy and the expression of Na+/K+-ATPase showed a good correlation indicating that Na+/K+-ATPase plays an important role in transportation for Tl-201 to go through the tumour cell membrane. CONCLUSIONS: Na+/K+-ATPase is one of the most important factors for Tl-201 accumulation in tumour.

Adenocarcinoma↗
PubMed2005

Expression of permeability-glycoprotein (P-gp) and uptake of technetium-99m-hexakis-2-methoxy-isobutyl-isonitrile (99Tcm-MIBI) in malignant tumour of the head and neck.

OBJECTIVES: The purpose of this study is to estimate the role of permeability-glycoprotein (P-gp) in the technetium-99m-hexakis-2-methoxy-isobutyl-isonitrile (99Tc(m)-MIBI) scintigraphy. METHODS: 71 patients with squamous cell carcinoma (39 patients with well differentiated, 19 with moderately differentiated and 13 with poorly differentiated tumour) were examined. Eighteen of these patients underwent 99Tc(m)-MIBI scintigraphy (early and delayed scans). The tumour retention index, obtained from the ratio of the accumulation of the delayed scan to that of the early scan, was divided into three groups. The immunohistochemical evaluation of P-gp expression was performed in all 71 patients. Levels of the P-gp expression were classified into three grades (score 0, 1 and 2). Correlations among the tumour retention index, the P-gp expression and the tumour tissue differentiation were evaluated. RESULTS: 17 of 18 patients showed a decreasing of the tumour retention index ranging from 0.70 to 0.93 (mean+/-SD=0.850+/-0.071). The tumour retention index showed a statistical correlation with the P-gp expression and the tumour tissue differentiation (chi-squared=7.802>7.779, P=0.10 and 16.835>14.860, P=0.005, respectively). Moreover, there was a statistical correlation between the P-gp expression and the tumour tissue differentiation (chi-squared=14.863>14.860, P=0.005). CONCLUSION: There is a possibility that the P-gp expression is high in the high-grade malignant tumours and P-gp causes the decrease of tumour retention index.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2001

Involvement of polyamines in B cell receptor-mediated apoptosis: spermine functions as a negative modulator.

The B cell lymphoma WEHI231 has been used as a model for studying clonal deletion of B cells on the basis of its ability to undergo growth arrest and apoptosis by B cell antigen receptor (BCR) cross-linking. To comprehensively analyze the genes involved in BCR-mediated apoptosis, we applied the technique of serial analysis of gene expression (SAGE) to WEHI231. Comparison of expression patterns revealed that BCR cross-linking caused coordinate changes in the expression of genes involved in polyamine metabolism. Polyamines are ubiquitous compounds required for cell proliferation and homeostasis. The coordinate expression of the polyamine-related genes was confirmed by semiquantitative reverse transcriptase-polymerase chain reaction analysis. During apoptosis, the genes involved in polyamine biosynthesis were downregulated, whereas those involved in polyamine catabolism were upregulated, suggesting that intracellular polyamines play a role in BCR-mediated apoptosis. Levels of intracellular putrescine, spermidine, and spermine were reduced after BCR cross-linking. These effects were prevented by concurrent CD40 stimulation, which blocked BCR-mediated apoptosis. Furthermore, addition of spermine could repress the BCR-mediated apoptosis by attenuating the mitochondrial membrane potential (Deltapsim) loss and activation of caspase-7 induced by BCR signaling. These findings strongly suggest that polyamine regulation is involved in apoptosis during B cell clonal deletion.

Animals↗
PubMed2001

Dose escalation study of irinotecan combined with carboplatin for advanced non-small-cell lung cancer.

From December 1994 to July 1997, we conducted a dose escalation study of irinotecan combined with carboplatin in 17 patients with advanced non-small-cell lung cancer (NSCLC) to determine the maximum tolerated dose and the dose-limiting toxicities. Irinotecan was administered intravenously over 90 min on days 1, 8 and 15, with carboplatin given at an area under the concentration-time curve dose of 5 mg/ml x min (calculated using Calvert's formula) on day 1. The starting dose of irinotecan was 30 mg/m2 and dose escalation was done in 10-mg/m2 increments. Treatment was repeated at 28-day intervals for at least two cycles. The dose-limiting toxicities were neutropenia and thrombocytopenia, since three out of five patients given 60 mg/m2 of irinotecan developed grade 4 neutropenia and thrombocytopenia. The overall response rate was 35.3%. The median survival time and the 1-year survival rate were 10.5 months and 35.3%, respectively. The maximum tolerated dose of irinotecan with this regimen was 60 mg/m2, while 50 mg/m2 can be recommended for future use. Further studies of this combination in advanced NSCLC are warranted.

Adult↗
PubMed2001

Serial change in the atrial transport function after the radial incision approach.

BACKGROUND: The left atrial transport function recovers slowly over several months after the maze procedure (Maze), but remains at a low level even during the long-term postoperative period. Because the Maze leaves an insufficient left atrial transport function, patients may still be prone to thromboembolism after the Maze. The radial incision approach (Radial) has been shown to preserve greater atrial transport function than does the Maze in the early postoperative period. METHODS: To examine the serial change in the atrial transport function after the Radial, out of 32 patients who underwent the Radial, 15 patients were assessed by transthoracic Doppler echocardiography 1, 3, 6, and 12 months after surgery. The atrial filling fraction and peak A/E velocity ratio were determined from the flow-velocity spectra across the mitral and tricuspid valves. The incidence of thromboembolic events was examined in 21 patients who were followed for more than 3 months after the Radial. The data were compared with data obtained from 13 patients after (41 +/- 6 months) the Maze III procedure. RESULTS: The left atrial transport function after the Radial increased within 3 months to a significantly greater level than did that after the Maze in the longterm. The atrial filling fraction was 28.2% +/- 7.9% at 3 months after the Radial and 15.1% +/- 4.0% at 41 months after the Maze (p < 0.01). The peak A/E ratio was 0.52 +/- 0.18 at 3 months after the Radial and 0.25 +/- 0.07 at 41 months after the Maze (p < 0.01). This increased atrial transport function was maintained for an extended period after the Radial. There were no thromboembolic events in any of the patients after the Radial or Maze, irrespective of postoperative anticoagulant therapy. CONCLUSIONS: The Radial approach prevents thromboembolism by restoring sufficient atrial transport function more effectively and faster than does the Maze.

Aged↗
PubMed2001

A stone developed within the dilated intravesical ureter following ureteroscopy.

A 58-year-old man presented with a stone within the dilated intravesical ureter, which was probably attributable to a previous ureteroscopy. Transurethral incision of the right intravesical ureter and lithotripsy were carried out without subsequent urinary tract impairment. Although some complications resulting from ureteroscopy, such as ureteral stricture, ureteral perforation and vesicoureteral reflux, have been reported, this complication is considered to be very rare.

Humans↗
PubMed2001

Cryoablation of ventricular tachycardia guided by return cycle mapping after entrainment.

BACKGROUND: Although the implantable cardioverter-defibrillator effectively prevents sudden cardiac death, patients are still prone to recurrence of ventricular tachyarrhythmias. Electrophysiologically guided surgery is the most effective modality in abolishing ventricular tachycardia, having a lower recurrence rate than pharmacologic therapy or catheter ablation. Return cycle mapping after entrainment has been shown to localize the central common pathway, which is the target region for ablation, without pacing at the pathway or recording the potentials from the pathway. METHODS: To determine the accuracy and usefulness of return cycle mapping in surgery for ventricular tachycardia, we cryoablated 8 morphologies of ventricular tachycardia induced in postinfarction dogs with the guidance of return cycle mapping. The ventricular tachycardia was entrained from 3 to 5 different epicardial sites at a paced cycle length 10 to 20 ms shorter than the ventricular tachycardia cycle length and the epicardium was mapped with 61 unipolar electrodes during cessation of entrainment to construct return cycle maps. The return cycle was determined by subtracting the first activation time from the second activation time after the last stimulus in each electrode location, and the maps were then displayed on a computer. RESULTS: The total analysis process was completed within 3 minutes by means of a computer with custom-made programs. The activation map during ventricular tachycardia did not localize the central common pathway in any morphology of ventricular tachycardia, because the pattern of activation was concentric and diastolic potentials were not recorded. Cryoablation of the region where the isotemporal lines of the return cycle equal to the ventricular tachycardia cycle length intersected resulted in termination of ventricular tachycardia in all morphologies. The intersection was 26 +/- 9 mm from the earliest activation site. Epicardial mapping with 253 electrodes during cryothermia showed that the region localized by return cycle mapping was the central common pathway sandwiched between the lines of conduction block and that the cryolesion connected the lines of block, blocked the rotating wave front, and resulted in termination of the ventricular tachycardia. CONCLUSION: Return cycle mapping provides an accurate and rapid means of localizing the central common pathway without the need for recording potentials from the pathway or pacing at the pathway in ablation for ventricular tachycardia.

Animals↗
PubMed2001

Human T-cell leukemia virus type 1 (HTLV-1) infection of mice: proliferation of cell clones with integrated HTLV-1 provirus in lymphoid organs.

Human T-cell leukemia virus type 1 (HTLV-1) is suggested to cause adult T-cell leukemia after 40 to 50 years of latency in a small percentage of carriers. However, little is known about the pathophysiology of the latent period and the reservoir organs where polyclonal proliferation of cells harboring integrated provirus occurs. The availability of animal models would be useful to analyze the latent period of HTLV-1 infection. At 18 months after HTLV-1 infection of C3H/HeJ mice inoculated with the MT-2 cell line, which is an HTLV-1-producing human T-cell line, HTLV-1 provirus was detected in spleen DNA from eight of nine mice. No more than around 100 proviruses were found per 10(5) spleen cells. Cellular sequences flanking the 3' long terminal repeat (LTR) and the clonalities of the cells which harbor integrated HTLV-1 provirus were analyzed by linker-mediated PCR. The results showed that the flanking sequences are of mouse genome origin and that polyclonal proliferation of the spleen cells harboring integrated HTLV-1 provirus had occurred in three mice. A sequence flanking the 5' LTR was isolated from one of the mice and revealed the presence of a 6-nucleotide duplication of cellular sequences, consistent with typical retroviral integration. Moreover, PCR was performed on DNA from infected tissues, with LTR primers and primers derived from seven novel flanking sequences of the three mice. Data revealed that the expected PCR products were found from lymphatic tissues of the same mouse, suggesting that the lymphatic tissues were the reservoir organs for the infected and proliferating cell clones. The mouse model described here should be useful for analysis of the carrier state of HTLV-1 infection in humans.

Animals↗
PubMed2001

Syncope induced by tobacco smoking in the head-up position.

A 26-year-old man had a loss consciousness for a few minutes while smoking in the standing position, and was referred to hospital. No abnormalities were found in a computed tomography examination of his head, in a 24-h electrocardiogram or in an exercise tolerance test. The head-up tilt test (HUT) while tobacco smoking elicited a positive response in the tilted position, but the HUT without tobacco smoking was negative. The most noteworthy effect of tobacco smoking during the HUT was the high level of plasma epinephrine compared to the levels seen during supine smoking or the HUT alone. Syncope induced by tobacco smoking in the standing position is rare and the mechanism may be the same as that underlying neurally mediated syncope.

Adult↗
PubMed2001

Carboplatin calculated with Chatelut's formula plus etoposide for elderly patients with small-cell lung cancer.

OBJECTIVE: This dose escalation was conducted to evaluate the applicability of Chatelut's dosing, and to determine the efficacy and toxicity of carboplatin with etoposide in previously untreated elderly patients (>70 years) with small cell lung cancer. PATIENTS AND METHODS: Seventeen patients were treated with etoposide for 3 days and carboplatin calculated dose using Chatelut's formula on day 1 intravenously. The starting doses of etoposide on days 1 to 3, and carboplatin using the area under the concentration versus time curve (AUC) were 90 mg/m2 and 4 mg/ml x min, respectively. RESULTS: The median age was 77 years (range 71 to 87). Dose-limiting toxicity (DLT) was seen at level 4 (AUC 5 mg/ml x min of carboplatin and etoposide 100 mg/m2). Hematologic toxicity was the primary DLT. Grade 4 thrombocytopenia and Grade 4 leukopenia were observed at level 4. Non-hematologic toxicity was insignificant. The overall response rate was 94%. CONCLUSION: Etoposide at 100 mg/m2 and AUC of carboplatin of 4.5 mg/ml x min as calculated using Chatelut's formula every four weeks is the recommended dose for further phase II trials for elderly patients with small cell lung cancer.

Aged↗
PubMed2001

[Availability of NMP22 (nuclear matrix protein 22) for the diagnosis of urothelial cancer].

We evaluated the availability of NMP22 for the diagnosis of urothelial cancer. Of 154 patients with gross hematuria or microscopic hematuria, 14 patients with bladder cancer and 4 patients with upper urothelial cancer were detected. Of 73 patients continued to be followed for urothelial cancers, 11 patients with bladder cancer were detected. NMP22 was not available when a large number of RBC was present in urine. Also, NMP22 was significantly higher in patients with urothelial cancers. Interpretation of the ROC curve indicated an optimal cutoff value of 9.2 u/ml. Using 9.2 u/ml as a cutoff, the sensitivity and specificity were, respectively 87.0% and 64.0% in patients with hematuria, and 81.8% and 78.7% in patients with a history of TCC. This indicated that when NMP22 was used for the diagnosis of urothelial cancers, 12.0 u/ml, the value recommended as a cutoff in Japan, might be too high to differentiate patients with urothelial cancers.

Biomarkers, Tumor↗
PubMed2001

[Small cell carcinoma of the urinary bladder: a case report].

We report a case of small cell carcinoma of the urinary bladder. A 60-year-old man with microscopic hematuria was referred to our hospital. Cystoscopy revealed a sessile tumor on the left lateral wall of the urinary bladder. The patient underwent transurethral resection of the bladder tumor (TUR-Bt). Because of muscle invasion (pT2), total cystectomy was recommended, but was not performed because the patient would not give consent for the operation. Six months after TUR-Bt, invasive bladder tumor recurred and total cystectomy was performed. Pathological examination of the operative specimen revealed small cell carcinoma. Adjuvant combined therapy of irradiation and chemotherapy (nedaplatin and etoposide) was ineffective. Metastases to retroperitoneal lymph nodes, lung and liver were detected soon after the adjuvant therapy. The patient died 15 months after his first visit to our hospital.

Carcinoma, Small Cell↗
PubMed2000

Immunohistochemical study of MUC1 mucin in premalignant oral lesions and oral squamous cell carcinoma: association with disease progression, mode of invasion, and lymph node metastasis.

BACKGROUND: MUC1 mucin is a transmembrane, mucin-like glycoprotein encoded by the MUC1 gene. Although MUC1 expression has been identified in a variety of neoplastic tissues, to the authors' knowledge, few studies have examined MUC1 expression in premalignant and malignant oral lesions. METHODS: A total of 36 specimens of oral epithelial dysplasia, 12 carcinoma in situ (CIS) specimens and 77 specimens of oral squamous cell carcinoma (OSCC), were examined by both light and electron microscopy using immunohistochemical staining of MUC1 mucin. Relations between staining patterns and clinicopathologic findings also were examined. RESULTS: Distinct membrane MUC1 mucin staining patterns were identified in epithelial dysplasia (33.0%), CIS (50.0%), and OSCC (59.7%) cases. A predominantly cytoplasmic staining pattern was detected in epithelial dysplasia (5.6%), CIS (41.7%), and OSCC (32.5%) cases. Significant positive correlations were found between MUC1 mucin membranous immunoreactivity and disease progression from epithelial dysplasia to OSCC (P < 0.01), mode of tumor invasion (P < 0.02), and lymph node metastasis (P < 0.01). Furthermore, the malignant transformation of oral epithelium, tumor invasion, and tumor metastasis were associated with higher MUC1 mucin expression in the cytoplasm (P < 0.01). In addition to the usual cell surface expression, cytoplasmic expression of MUC1 mucin was confirmed by colloidal gold labeling with transmission electron microscopy. CONCLUSIONS: The results of the current study suggest that determination of MUC1 mucin expression may be a parameter in the diagnosis of premalignant and malignant lesions arising in the oral cavity and that this expression may affect the malignant behavior of OSCC. MUC1 mucin expression may be a useful diagnostic marker for prediction of the invasive/metastatic potential of OSCC.

Carcinoma, Squamous Cell↗