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Biomedical subjects

M Sumi

Publications and source records attributed to M Sumi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Comparison of sonography and CT for differentiating benign from malignant cervical lymph nodes in patients with squamous cell carcinoma of the head and neck.

OBJECTIVE: We compared the ability of sonography and CT to differentiate benign from malignant cervical lymph nodes in patients with squamous cell carcinoma of the head and neck. MATERIALS AND METHODS: We analyzed 209 cervical nodes (102 metastatic and 107 nonmetastatic) from 62 patients with head and neck cancer. These nodes were topographically correlated by node between images and surgical specimens, and accordingly between sonography and CT. RESULTS: The area under the receiver operating characteristic curve (A(z) value) for the overall impressions of metastatic or nonmetastatic nodes was significantly greater for sonography (power Doppler sonography plus gray-scale sonography, 0.97 +/- 0.005; gray-scale sonography, 0.95 +/- 0.004) than for CT (0.87 +/- 0.018). Receiver operating characteristic curve analysis also showed that the greater ability of sonography to depict the internal architecture of the nodes (A(z) value, 0.96 +/- 0.006) compared with CT (A(z) value, 0.81 +/- 0.027) significantly contributed to the better performance of sonography compared with CT in diagnosing metastatic nodes in the neck. On the other hand, size criterion (the short-axis diameter) was equally predictive in sonography and CT. The greater contributions of internal architectures relative to the size criterion of the node in the sonographic assessment for metastatic nodes were further evidenced by the findings that sonography provided higher sensitivity and specificity than CT did, whereas the cutoff points for the short-axis diameter in both tests were equivalent. CONCLUSION: Sonography performed significantly better than CT in depicting cervical metastatic nodes. Sonography could be a useful adjunct to CT in surveying cervical metastatic nodes.

Aged↗
PubMed2001

Contribution of doppler sonography blood flow information to the diagnosis of metastatic cervical nodes in patients with head and neck cancer: assessment in relation to anatomic levels of the neck.

BACKGROUND AND PURPOSE: Although sonographic evaluation of cervical adenopathy by use of size criteria is effective, the sensitivity and specificity fall short of that required to make adequate judgments regarding neck dissection. Therefore, we tested whether the combined use of size criteria and Doppler sonographic findings would improve the predictive ability for metastatic cervical nodes. METHODS: We analyzed 338 histologically proved cervical lymph nodes (108 metastatic and 230 nonmetastatic) in 73 patients with head and neck cancer. The sonographic topography of the nodes was compared with dissected specimens, and their position in the neck was categorized into three levels (I, II, and III+IV). The diagnostic accuracy of sonography was evaluated by using the single criterion of short-axis diameter of the node or by the combined criteria of short-axis diameter and Doppler blood flow features (the absence or presence of normal hilar flow). RESULTS: As compared with the single criterion of short-axis nodal diameter, the combined criteria of nodal size and Doppler blood flow patterns increased the diagnostic accuracy of sonography at all levels in the neck. Accordingly, the best cut-off values were improved to 6, 7, and 5 mm for nodes at levels I, II, and III+IV, respectively. In addition, the combined criteria yielded high sensitivites (> or = 89%) and specificities (> or = 94%). CONCLUSION: Hilar blood flow information obtained by Doppler sonography significantly improves diagnostic accuracy for the detection of nodes metastatic from head and neck squamous cell carcinoma.

Aged↗
PubMed2001

[Right ventricular outflow tract reconstruction for pulmonary atresia with ventricular septal defect: the possibility of ventriculo-arterial direct anastomosis].

Between September 1997 and December 2000, 29 patients with pulmonary atresia associated with ventricular septal defect were undergone corrective surgery. The age at operation ranged from 24 days to 14.7 years. The 5 patients were younger than 3 months. The body weight at operation ranged from 1.5 kg to 35.8 kg. 10 patients had MAPCAs. 21 patients had been undergone modified Blolock-Taussig shunt and/or uniforcalization of pulmonary artery (PA). We could perform right ventricular outflow tract reconstruction with ventriculo-arterial direct anastomosis in 19 patients (65%) (4/10; patients with MAPCAs, 3/5; younger than 3 months). We performed pulmonary angioplasty on stenotic and/or underdeveloped leasions as a concomitant procedure in 13/19 cases. Our technique is composed of 4 points, (1) fully mobilizing central and distal pulmonary artery (PA), (2) dissecting the PA with connective tissue together, (3) pulmonary arterial wall flap, (4) right ventricular outflow tract reconstruction during cardiac arrest.

Adolescent↗
PubMed2000

Fractionated stereotactic radiotherapy of brain metastases from renal cell carcinoma.

PURPOSE: To retrospectively evaluate the effectiveness of fractionated stereotactic radiotherapy (FSRT) for brain metastases from renal cell carcinoma (RCC). METHODS AND MATERIALS: From May 1983 to September 1998, 35 patients with brain metastases from RCC underwent radiotherapy at the National Cancer Center Hospital, Tokyo; 10 patients treated initially with FSRT (FSRT group); 11 with surgery followed by conventional radiotherapy (S/CR group); and 14 with conventional radiotherapy (CR group). Survival and local control rates were determined for patients who had an ECOG performance status of 0-2. RESULTS: Overall median survival rate was 18 months, and actuarial 1- and 2-year survival rates were 57.6% and 31.0%, respectively. Median survival rates were 25.6 months for the FSRT group, 18.7 months for the S/CR group, and 4.3 months for the CR group. Significant prognostic factors associated with survival were age less than 60 years and good performance status. In patients treated with FSRT, imaging studies revealed that 21 of 24 tumors (88%) were locally controlled during a median follow-up time of 5.2 months (range 0.5-68). Actuarial 1- and 2-year local control rates were 89.6% and 55.2%, respectively. No patient suffered from acute or late complications during and following FSRT. CONCLUSIONS: FSRT offers better tumor control and prolonged survival over the S/CR or CR groups, and should be considered as primary treatment for brain metastases from RCC. Patients under 60-years-old and those with a good performance status at the beginning of radiotherapy had a better prognosis.

Brain Neoplasms↗
PubMed2000

The external radiotherapy with three-dimensional conformal boost after the neoadjuvant androgen suppression for patients with locally advanced prostatic carcinoma.

PURPOSE: To analyze the results in patients with locally advanced prostatic carcinoma treated by hormonal therapy followed by external radiotherapy using three-dimensional conformal radiation therapy (3D-CRT) boost. METHODS AND MATERIALS: From 1987 to 1995, 46 patients with histologically proven locally advanced adenocarcinoma of the prostate were treated with 3D-CRT at the National Cancer Center Hospital, Tokyo. The neoadjuvant androgen suppression started immediately after the diagnosis followed by radical radiation therapy, according to the prospective protocol. They were treated with photons of 6-14 MV for wide fields and the boost, of which a multiple-leaf collimator of 2-cm width was available. The boosted dose was delivered with the rotational 3D-CRT, after the delivery of whole pelvis 4-field box from a dose of 40-46 Gy up to 66 Gy. The planning target volume encompassed 1 cm outside throughout the clinical target volume, and the prostate and the seminal vesicles were included in the boost field. RESULTS: The 3D-CRT boost treatment completed as planned in all 46 patients. The median follow-up for all the patients was 60 months (range, 5-120 months). Nineteen of 46 patients died. Of these, 11 patients died of the intercurrent diseases. For all 46 patients, the 5- and 8-year overall survival rates were 61.3% and 42.4%, and the 5- and 8-year cause-specific survival rates were 82.4% and 64.4%, respectively. The prostate-specific antigen (PSA) relapse-free rates for 5- and 8-year were 64.6% and 52.5%, and the clinical local control rates for 5 and 8 years were 75.3% and 69.9%, respectively. The preradiation therapy PSA and the Gleason score were the factors that significantly associated with PSA relapse-free survival. Sixteen of 46 patients (35%) showed at least one form of late toxicities. Of these, 3 patients experienced late complications of Grade 3 (urinary, 2, proctitis, 1). CONCLUSION: The treatment results were fairly good and were consistent with those in Western countries, indicating that this study shows the preliminary status of 3D-CRT for the locally advanced prostate cancer in Japan. Preradiation therapy PSA seems to be a significant predictor of PSA relapse-free survival (p = 0.004) after neoadjuvant androgen suppression.

Adenocarcinoma↗
PubMed2000

Radiotherapy for hepatocellular carcinoma.

PURPOSE: To retrospectively evaluate the effectiveness of radiotherapy with or without transarterial embolization (TAE) and/or percutaneous ethanol injection (PEI) in patients with hepatocellular carcinoma who were ineligible for surgery. PATIENTS AND METHODS: From October 1984 to November 1997, 62 patients underwent radiotherapy receiving 50 to 70 Gy in 25 to 35 treatments with or without transarterial embolization and/or percutaneous ethanol injection and were followed for a median period of 8.6 months (1.5 to 92 months). RESULTS: Overall median survival rates were 9.5 months. Significant prognostic factors were the extent of pretreatment liver function impairment, radiation field size and the existence of tumor thrombosis. Six-month and 1-year local control rates were 67 and 54%, respectively. Seven of the 8 patients who suffered from hepatic failure had poor pretreatment liver functions. CONCLUSION: Radiotherapy with or without transarterial embolization and/or percutaneous ethanol injection appears effective in controlling hepatocellular carcinoma and prolonged survival. Individualized treatment strategies are presented depending on the tumor presentation and the degree of liver function impairment.

Aged↗
PubMed2000

The M intermediate of Pharaonis phoborhodopsin is photoactive.

The retinal protein phoborhodopsin (pR) (also called sensory rhodopsin II) is a specialized photoreceptor pigment used for negative phototaxis in halobacteria. Upon absorption of light, the pigment is transformed into a short-wavelength intermediate, M, that most likely is the signaling state (or its precursor) that triggers the motility response of the cell. The M intermediate thermally decays into the initial pigment, completing the cycle of transformations. In this study we attempted to determine whether M can be converted into the initial state by light. The M intermediate was trapped by the illumination of a water glycerol suspension of phoborhodopsin from Natronobacterium pharaonis called pharaonis phoborhodopsin (ppR) with yellow light (>450 nm) at -50 degrees C. The M intermediate absorbing at 390 nm is stable in the dark at this temperature. We found, however, that M is converted into the initial (or spectrally similar) state with an absorption maximum at 501 nm upon illumination with 380-nm light at -60 degrees C. The reversible transformations ppR if M are accompanied by the perturbation of tryptophan(s) and probably tyrosine(s) residues, as reflected by changes in the UV absorption band. Illumination at lower temperature (-160 degrees C) reveals two intermediates in the photoconversion of M, which we termed M' (or M'(404)) and ppR' (or ppR'(496)). A third photoproduct, ppR'(504), is formed at -110 degrees C during thermal transformations of M'(404) and ppR'(496). The absorption spectrum of M'(404) (maximum at 404 nm) consists of distinct vibronic bands at 362, 382, 404, and 420 nm that are different from the vibronic bands of M at 348, 368, 390, and 415 nm. ppR'(496) has an absorption band that is shifted to shorter wavelengths by 5 nm compared to the initial ppR, whereas ppR'(504) is redshifted by at least 3 nm. As in bacteriorhodopsin, photoexcitation of the M intermediate of ppR and, presumably, photoisomerization of the chromophore during the M --> M' transition result in a dramatic increase in the proton affinity of the Schiff base, followed by its reprotonation during the M' --> ppR' transition. Because the latter reaction occurs at very low temperature, the proton is most likely taken from the counterion (Asp(75)) rather than from the bulk. The phototransformation of M reveals a certain heterogeneity of the pigment, which probably reflects different populations of M or its photoproduct M'. Photoconversion of the M intermediate provides a possible pathway for photoreception in halobacteria and a useful tool for studying the mechanisms of signal transduction by phoborhodopsin (sensory rhodopsin II).

Archaeal Proteins↗
PubMed2000

Long-term observations of a patient with choroidal melanoma following fractionated stereotactic radiotherapy: a case report.

A 60-year-old man with choroidal melanoma was treated with fractionated stereotactic radiotherapy and followed for 6 years. During this period, the tumor has not changed in size, and the patient has experienced only a slight decrease in visual acuity. In this case, stereotactic radiotherapy appears to have been safe and effective and may also be a cost-effective alternative to particle or plaque therapy.

Choroid Neoplasms↗
PubMed2000

CT-assisted transbronchial brachytherapy for small peripheral lung cancer.

Transbronchial brachytherapy for small peripheral lung cancer was developed with the use of the CT-guided bronchoscopy technique. Under CT guidance, an applicator carrying a dummy source was introduced into a lesion and stabilized. A radioactive source was then delivered through the applicator using a high dose rate remote afterloading system. For multiple radiation fractions, a marker was placed immediately under the pleura in a peripheral bronchus penetrating the lesion using the CT-guided barium marking technique. During brachytherapy, an applicator with a dummy source was inserted under fluoroscopic guidance up to the marker. A radioactive source was subsequently delivered. CT-assisted transbronchial brachytherapy allows radiation to be delivered from inside a lesion. This minimizes radiation damage to noncancerous tissue and offers distinct advantages over conventional radiation techniques.

Adenocarcinoma↗
PubMed2000

Platinum-based chemotherapy with or without thoracic radiation therapy in patients with unresectable thymic carcinoma.

BACKGROUND: Thymic carcinoma is a rare mediastinal neoplasm with poor prognosis. Although the clinical benefit of chemotherapy for thymic carcinoma is controversial, cisplatin-based chemotherapy with or without radiation therapy is ordinarily adopted in advanced cases. We evaluated the clinical outcome of platinum-based chemotherapy with or without radiation therapy in unresectable thymic carcinoma patients. METHODS: Ten patients with unresectable thymic carcinoma were treated with platinum-based chemotherapy with or without radiation therapy in the National Cancer Center Hospital between 1989 and 1998. We reviewed the histological type, treatment, response and survival of these patients. RESULTS: Four of the 10 patients responded to chemotherapy and both the median progression-free survival period and the median response duration were 6.0 months. The median survival time was 11.0 months. There was no relationship between histological classification and prognosis. CONCLUSIONS: Platinum-based chemotherapy with or without thoracic radiation is, regardless of tumor histology, marginally effective in advanced thymic carcinoma patients, giving only a modest tumor response rate and short response duration and survival.

Adult↗
PubMed2000

Effects of three characteristic amino acid residues of pharaonis phoborhodopsin on the absorption maximum.

Phoborhodopsin (pR or sensory rhodopsin II, sRII) or pharaonis phoborhodopsin (ppR or pharaonis sensory rhodopsin II, psRII) has a unique absorption maximum (lambda max) compared with three other archaeal rhodopsins: lambda max of pR or ppR at ca 500 nm and others at 560-590 nm. Alignment of amino acid sequences revealed three sites characteristic of the shorter wavelength-absorbing pigments. The amino acids of these three sites are conserved completely among archaeal rhodopsins having longer lambda max, and are different from those of pR or ppR. We replaced these amino acids of ppR with amino acids corresponding to those of bacteriorhodopsin, Val-108 to Met, Gly-130 to Ser and Thr-204 to Ala. The lambda max of V108M mutant was 502 nm with a slight redshift. G130S and T204A mutants had lambda max of 503 and 508 nm, respectively. Thus, each site contributes only a small effect to the color tuning. We then constructed three double mutants and one triple mutant. The opsin-shifts of these mutants suggest that Val-108 and Thr-204 or Gly-130 are synergistic, and that Gly-130 and Thr-204 work additively. Even in the triple mutant, the lambda max was 515 nm, an opsin-shift only ca 30% of the shift value from 500 to 560 nm. This means that there is another yet unidentified factor responsible for the color tuning.

Amino Acid Sequence↗
PubMed2000

[Clinical quality assurance at institutions according to a patterns of care study. Japanese PCS Working Group].

The clinical quality assurance (QA) of an institution is important in any multiinstitutional prospective study. Patterns of Care Study (PCS) is a well-known study for QA activity in the United States. PCS is a nationwide retrospective study done by two-staged cluster sampling of institutions and patients and external audits. After data are accumulated, National averages on various survey items are calculated as a QA measure. In 1996, PCS was imported into the radiation oncology field in Japan with the support of the Ministry of Health and Welfare. Preliminary results showed significant differences in treatment process, structure, and preliminary outcome according to the stratification of institutions. These data can be useful in improving the structure and process at the institutional as well as the national level. PCS will also clarify the dissemination of positive clinical results into national practice.

Esophageal Neoplasms↗
PubMed1999

Developmental and dynamic canal stenosis as radiologic factors affecting surgical results of anterior cervical fusion for myelopathy.

STUDY DESIGN: The correlation between preoperative and postoperative lateral functional radiograms and clinical results was analyzed in 74 cases of myelopathy treated by anterior cervical fusion. OBJECTIVES: To clarify the correlation between clinical results and radiologic findings (developmental and dynamic stenosis). SUMMARY OF BACKGROUND DATA: Although radiologic changes have been reported at the disc level adjacent to anterior cervical fusion, the question of whether these radiologic findings affect the clinical results of anterior fusion has not been resolved. METHODS: The "deteriorated" results group (28 cases) was composed of cases with deterioration of 2 points or more in the Japan Orthopedic Association score at follow-up compared with the postoperative best score. The "good" results group (46 cases) exhibited a recovery rate of > or = 50%. The two groups were compared in lateral functional roentgenograms on which the sagittal canal diameter in each vertebra and the diameter between the inferoposterior lip of the vertebral body and the anterior margin of the lamina of the distal vertebra in the extended neck were measured. A diameter of less than 12 mm was defined as developmental canal stenosis or dynamic canal stenosis. RESULTS: Fifty-four percent of the cases in the deteriorated results group had developmental canal stenosis, whereas the same findings were identified in only 2% of the cases in the good results group (P < 0.01). Preoperative dynamic canal stenosis at the disc level adjacent to the fusion was found in 64% of the patients in the deteriorated results group and in only 4% of the patients in the good results group (P < 0.01). CONCLUSIONS: Patients in the deteriorated results group showed a higher incidence of preoperative developmental and/or dynamic canal stenosis at the adjacent disc level than those in the the good results group. These results indicate that patients with preoperative developmental canal stenosis are not suitable candidates for anterior cervical fusion. When dynamic canal stenosis is found below or above the level of fusion, simultaneous fusion is recommended to avoid deterioration of the myelopathy.

Cervical Vertebrae↗
PubMed1999

Positioning proton-donating residues to the Schiff-base accelerates the M-decay of pharaonis phoborhodopsin expressed in Escherichia coli.

Phoborhodopsin (also called sensory rhodopsin II, sR-II) is a receptor for the negative phototaxis of Halobacterium salinarum (pR), and pharaonis phoborhodopsin (ppR) is the corresponding receptor of Natronobacterium pharaonis. pR and ppR are retinoid proteins and have a photocycle similar to that of bacteriorhodopsin (bR). A major difference between the photocycle of the ion pump bR and the sensor pR or ppR is found in their turnover rates which are much faster for bR. A reason for this difference might be found in the lack of a proton-donating residue to the Schiff base which is formed between the lysine of the opsin and retinal. To reconstruct a bR-like photochemical behavior, we expressed ppR mutants in Escherichia coli in which proton-donating groups have been reintroduced into the cytoplasmic proton channel. In measurement of the photocycle it could be shown that the F86D mutant of ppR (Phe86 was substituted by Asp) showed a faster decay of M-intermediate than the wild-type, which was even accelerated in the F86D/L40T double mutant.

Archaeal Proteins↗
PubMed1999

Molecular identification of human G-substrate, a possible downstream component of the cGMP-dependent protein kinase cascade in cerebellar Purkinje cells.

G-substrate, an endogenous substrate for cGMP-dependent protein kinase, exists almost exclusively in cerebellar Purkinje cells, where it is possibly involved in the induction of long-term depression. A G-substrate cDNA was identified by screening expressed sequence tag databases from a human brain library. The deduced amino acid sequence of human G-substrate contained two putative phosphorylation sites (Thr-68 and Thr-119) with amino acid sequences [KPRRKDT(p)PALH] that were identical to those reported for rabbit G-substrate. G-substrate mRNA was expressed almost exclusively in the cerebellum as a single transcript. The human G-substrate gene was mapped to human chromosome 7p15 by radiation hybrid panel analysis. In vitro translation products of the cDNA showed an apparent molecular mass of 24 kDa on SDS/PAGE which was close to that of purified rabbit G-substrate (23 kDa). Bacterially expressed human G-substrate is a heat-stable and acid-soluble protein that cross-reacts with antibodies raised against rabbit G-substrate. Recombinant human G-substrate was phosphorylated efficiently by cGMP-dependent protein kinase exclusively at Thr residues, and it was recognized by antibodies specific for rabbit phospho-G-substrate. The amino acid sequences surrounding the sites of phosphorylation in G-substrate are related to those around Thr-34 and Thr-35 of the dopamine- and cAMP-regulated phosphoprotein DARPP-32 and inhibitor-1, respectively, two potent inhibitors of protein phosphatase 1. However, purified G-substrate phosphorylated by cGMP-dependent protein kinase inhibited protein phosphatase 2A more effectively than protein phosphatase 1, suggesting a distinct role as a protein phosphatase inhibitor.

Amino Acid Sequence↗
PubMed1999

Quantitative detection of hepatitis B virus by transcription-mediated amplification and hybridization protection assay.

We have developed a sensitive and quantitative assay using transcription-mediated amplification and hybridization protection assay for the detection of hepatitis B virus (HBV) DNA in serum. The transcription-mediated amplification was carried out in a single tube. The hybridization protection assay was carried out in a microtiter plate with two probes with different specific activities to obtain a broad detection range. As a result, the assay had a detection range of 5 x 10(3) to 5 x 10(8) genome equivalents (GE)/ml and good quantitative accuracy on a logarithmic scale. A moderately sized manual assay run can be completed within 5 h. Measurements of the amounts of HBV DNA in clinical samples by the assay showed the amounts under various disease conditions to be widely distributed (more than 5 logs, from approximately 5 x 10(3) to 5 x 10(8) GE/ml). It was also shown that the amount of HBV DNA in one chronic hepatitis patient varied widely, with a range of more than 5 logs during long-term monitoring. Our assay has the potential to be used to monitor and determine the prognosis of HBV patients and carriers, especially during interferon treatment.

Carcinoma, Hepatocellular↗
PubMed1999

Sublingual gland: MR features of normal and diseased states.

OBJECTIVE: We describe the MR features of the sublingual gland in normal and diseased states. SUBJECTS AND METHODS: We used MR imaging to assess age-related changes in size and signal intensity of normal sublingual glands in 60 control subjects. The MR features of sublingual glands were also studied in 70 patients with cancer, cellulitis of the sublingual space, Sjögren's syndrome, or ranula. RESULTS: MR imaging efficiently revealed normal sublingual glands. On T1-weighted images, the MR signal intensity of the sublingual gland was lower than that of the surrounding fat but higher than that of muscle. The sublingual glands showed age-related decreases in size, with approximately 25% of the thickness present in the second decade of life being lost by the seventh decade. T1-weighted signal intensity of the parotid gland increased with age, but the signal intensity of the sublingual and submandibular glands did not. T1-weighted signal intensity of carcinomas in and near the sublingual space was lower than that of the sublingual glands, but T2-weighted signal intensity of carcinomas exceeded that of the glands. Gadolinium enhancement occasionally diminished the contrast between invading carcinomas and the glands. T1-weighted MR imaging showed that sublingual glands affected by Sjögren's syndrome exhibit features analogous to those of the other major salivary glands; however, the sublingual glands seemed to be less severely involved overall in this syndrome than the other major glands. We found that using fat suppression and short inversion time inversion recovery may be useful for assessment of sialadenitis of the gland. CONCLUSION: MR imaging is useful in depicting normal and diseased states of the sublingual gland.

Adolescent↗