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T Hirai

Publications and source records attributed to T Hirai.

At least 199 records · Page 11Linked to original sources
PubMed1998

[Long-term survival in surgical cases of non-small cell lung cancer with mediastinal nodal involvement].

We studied long-result of the patients with mediastinal lymph node metastasis (N2) in lung cancer. From 1981 to 1991 in National Sanatorium Nishi-Gunma Hospital, we have performed a lobectomy or pneumonectomy with mediastinal lymph node dissection for 306 patients with non-small cell lung cancer. Six operative deaths were excluded (operative death rate: 2.0%). Of these, 53 patients (17%) were diagnosed as adenocarcinoma or squamous cell carcinoma with N2 disease pathologically. The patient consisted of 31 men and 22 woman whose ages ranged from 18 to 73 years, with a mean age of 58.1 years. The results were: Mean survival period was 39 month. Five-and 10-year survival rates were 18.9% and 12.6%, respectively. By motive of detection, the group of following other disease had a better prognosis than the group of having symptom. By pT-factor, T1 had a better prognosis than T3. By the number of nodal involvement level, 1 level had a better prognosis to compared to 3 or more than 4 levels. There were 10 patients of 5-year or over survivors after surgery, none of whom had primary site in left upper lobe. Analysis with a Cox's proportional hazard model demonstrated that the number of nodal involvement level was a useful factor in prognosis.

Adolescent↗
PubMed1997

Surface of bacteriorhodopsin revealed by high-resolution electron crystallography.

Bacteriorhodopsin is a transmembrane protein that uses light energy, absorbed by its chromophore retinal, to pump protons from the cytoplasm of bacteria such as Halobacterium salinarium into the extracellular space. It is made up of seven alpha-helices, and in the bacterium forms natural, two-dimensional crystals called purple membranes. We have analysed these crystals by electron cryo-microscopy to obtain images of bacteriorhodopsin at 3.0 A resolution. The structure covers nearly all 248 amino acids, including loops outside the membrane, and reveals the distribution of charged residues on both sides of the membrane surface. In addition, analysis of the electron-potential map produced by this method allows the determination of the charge status of these residues. On the extracellular side, four glutamate residues surround the entrance to the proton channel, whereas on the cytoplasmic side, four aspartic acids occur in a plane at the boundary of the hydrophobic-hydrophilic interface. The negative charges produced by these aspartate residues is encircled by areas of positive charge that may facilitate accumulation and lateral movement of protons on this surface.

Bacteriorhodopsins↗
PubMed1997

The 3.0 A projection structure of microsomal glutathione transferase as determined by electron crystallography of p 21212 two-dimensional crystals.

Two-dimensional crystals of rat microsomal glutathione transferase were grown during dialysis of detergent-solubilized enzyme after addition of a small amount of phospholipid. The crystals had two-sided plane group symmetry p21212 with a calibrated unit cell size of a=91.90 A, b=90.83 A. Electron diffraction patterns were recorded showing significant reflections extending to 3.0 A. A combination of these structure factor amplitudes with phases from high-resolution images following image processing was used to calculate a projection map of the protein. The asymmetric unit of the structure consists of three microsomal glutathione transferase molecules. The local 3-fold axis at the center of the trimer is delineated by six parallel alpha-helices, two from each monomer. The two helices differ significantly in their respective projection structure. The inner helical core of the trimer is partly surrounded by elongated domains with extensions towards the helices and which contain resolved density maxima at a spacing of 4 to 5 A. A well-defined strong peak is localized close to the elongated domain and at a distance of about 9.5 A from two of the inner helices.

Crystallization↗
PubMed1997

The three-dimensional structure of aquaporin-1.

The entry and exit of water from cells is a fundamental process of life. Recognition of the high water permeability of red blood cells led to the proposal that specialized water pores exist in the plasma membrane. Expression in Xenopus oocytes and functional studies of an erythrocyte integral membrane protein of relative molecular mass 28,000, identified it as the mercury-sensitive water channel, aquaporin-1 (AQP1). Many related proteins, all belonging to the major intrinsic protein (MIP) family, are found throughout nature. AQP1 is a homotetramer containing four independent aqueous channels. When reconstituted into lipid bilayers, the protein forms two-dimensional lattices with a unit cell containing two tetramers in opposite orientation. Here we present the three-dimensional structure of AQP1 determined at 6A resolution by cryo-electron microscopy. Each AQP1 monomer has six tilted, bilayer-spanning alpha-helices which form a right-handed bundle surrounding a central density. These results, together with functional studies, provide a model that identifies the aqueous pore in the AQP1 molecule and indicates the organization of the tetrameric complex in the membrane.

Animals↗
PubMed1997

Simultaneous analysis of several non-steroidal anti-inflammatory drugs in human urine by high-performance liquid chromatography with normal solid-phase extraction.

A practical and reproducible high-performance liquid chromatographic method using normal solid-phase extraction has been developed for the simultaneous analysis of twelve non-steroidal anti-inflammatory drugs (NSAIDs) in human urine. A urine specimen mixed with acetate buffer pH 5.0 was purified by solid-phase extraction on a Sep-Pak Silica cartridge. The analyte was chromatographed by a reversed-phase Inertsil ODS-2 column using a phosphate buffer-acetonitrile at pH 5.0 as the mobile phase, and the effluent from the column was monitored at 230 or 320 nm. Absolute recoveries were greater than 73% for all of the twelve NSAIDs. The present method enabled simple manipulation and isocratic HPLC with UV analysis as well as high sensitivity of 0.005 microg/ml for naproxen, and 0.05 microg/ml for sulindac, piroxicam, loxoprofen, ketoprofen, felbinac, fenbufen, flurbiprofen, diclofenac, ibuprofen and mefenamic acid as the quantitation limit in human urine using indomethacin as an internal standard.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1997

Determination of methotrexate and its main metabolite 7-hydroxymethotrexate in human urine by high-performance liquid chromatography with normal solid-phase extraction.

A practical and sensitive high-performance liquid chromatographic method using normal solid-phase extraction has been developed for the determination of methotrexate (MTX) and its main metabolite 7-hydroxymethotrexate (7-OH-MTX) in human urine. A urine specimen followed by the addition of pH 5.0 acetate buffer was purified by solid-phase extraction on a Sep-Pak silica cartridge. The analyte was chromatographed on a reversed-phase Inertsil ODS-2 column using phosphate buffer-acetonitrile at pH 5.3 as the mobile phase, and the effluent from the column was monitored at 303 nm. A good linear relationship between peak height and concentration was found for both of MTX and 7-OH-MTX in the range 5 to 1000 ng/ml of human urine. The inter-day coefficients of variation for the assay (n = 5) were 8.8% (5 ng/ml), 3.4% (50 ng/ml) and 2.0% (500 ng/ml) for MTX, and 7.2, 2.7 and 2.3% for 7-OH-MTX in urine, respectively. The present method should prove useful for the evaluation of urinary drug excretion in patients undergoing MTX low-dose therapy.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1997

Enhancing effect of thoraco-laparotomy on liver metastasis and the role played by active oxygens in its mechanism.

The enhancing effect on liver metastasis produced by the excessive surgical stress of thoraco-laparotomy (TL), and its regulation with a radical scavenger, were studied in 10-week-old Donryu rats. The rats were divided into three groups: those given thoraco-laparotomy for 1 h (the TL group); those given laparotomy alone for 1 h (the L group); those given a short laparotomy (the C group). The effects of treatment with 5 mg/kg of EPC-K1 was assessed in the TL group. A rat hepatocellular carcinoma cell line AH 60C (5 x 10(5) cells) was administered into the portal vein under general anesthesia. The number of metastatic liver nodules was counted 3 weeks later, and the lipid peroxide (LPO) levels of the liver and serum were measured by the TBA method on postoperative days (PODs) 1, 2, and 3. The number of metastatic liver nodules was 40.6 +/- 29.7, 15.0 +/- 15.8, and 13.7 +/- 9.4 in the TL, L, and C groups, respectively. When EPC-K1 was administered to the TL group, the LPO level on POD 1 decreased from 49.8 +/- 25.8 to 18.9 +/- 7.9 nM/g, and the number of metastatic liver nodules decreased from 27.2 +/- 30.0 to 8.9 +/- 12.7 in parallel. The findings of this study suggested that the excessive surgical stress produced by thoraco-laparotomy enhanced liver metastasis in parallel with an increase in LPO levels; however, the radical scavenger EPC-K1 could aid in reversing this effect.

Animals↗
PubMed1997

Dynamic MRI of meningiomas and schwannomas: is differential diagnosis possible?

We studied 23 patients with meningiomas and 14 with schwannomas using dynamic spin-echo (TR/TE 200/15 ms) MRI. Histologically the meningiomas were classified according to the 1993 WHO classification. Serial images were obtained every 30s for 210s after rapid injection of gadopentetate dimeglumine (0.1 mmol/kg). The contrast-enhancement ratio (CER) was divided into three patterns; a sharp rise with a peak within 60 s (A), a relatively rapid increase with a peak between 60 and 210s (B), a slow increase without a peak (C). The patterns were correlated with the histology of the tumors. The signal intensities of the tumours on T2-weighted images were also analyzed and correlated with the dynamic patterns. Meningiomas had more varied dynamic patterns than schwannomas. Almost half of the meningiomas showed pattern A, and one third pattern C. Of six meningiothelial meningiomas showed pattern A; all schwannomas and fibrous meningiomas showed pattern C. Various patterns were observed in transitional meningiomas. Of the 8 meningiomas showing pattern C, only one gave high signal on T2-weighted images, and could not be differentiated from the schwannomas. Thus, one third of meningiomas could not be differentiated from schwannomas by the dynamic contrast enhancement alone. However, when this was combined with the signal intensity on T2-weighted images, most meningiomas could be differentiated from schwannomas.

Brain↗
PubMed1997

Laparoscopic-assisted colon surgery by abdominal wall lifting with newly developed lifting bars.

BACKGROUND: The aim of the study is to evaluate the efficacy of laparoscopic-assisted colon surgery by lifting the abdominal wall with newly developed lifting bars. METHODS: We have made and used two kinds of lifting bars: type I and type T. Two I-type lifting bars are used in transverse colectomy and right hemicolectomy. One I-type lifting bar and one T-type bar are used in sigmoid colectomy and low anterior resection. After the intestine is dissected and the mesenterium is treated under laparoscopy, a small laparotomy wound about 4 to 6 cm long is made, and the intestine is pulled out of the body for extracorporeal anastomosis. RESULTS: The mean operating time was 153.8 +/- 51.9 min, and no particular complications were noted. CONCLUSIONS: Since postoperative pain is mild and postoperative recovery is rapid, this method is considered to be an effective surgical procedure.

Abdominal Muscles↗
PubMed1997

Tongue motor skills and masticatory performance in adult dentates, elderly dentates, and complete denture wearers.

STATEMENT OF PROBLEM: For complete denture wearers the tongue plays an important role in the retention and stability of dentures and has a great influence on masticatory function. PURPOSE OF STUDY: The purpose of this study was to elucidate the relationship between tongue motor behavior and masticatory function. MATERIAL AND METHODS: Thirty healthy, normal adult dentates, 10 normal elderly dentates, and 20 complete denture wearers whose dentures were constructed by the same methods and materials were selected. Tongue motor skills were examined by an ultrasound system and masticatory performance was evaluated by the sieving method. RESULTS: The tongue motor skills of elderly dentates and complete denture wearers were statistically lower compared with those of adult dentates (p < 0.05, Duncan test). Tongue motor skills of complete denture wearers were statistically correlated with age (p < 0.01). Masticatory performance was statistically lower in relation to age in complete denture wearers (p < 0.01). The correlation coefficient was 0.74 between tongue motor skill and masticatory performance in complete denture wearers, which was statistically significant (p < 0.01). CONCLUSION: Age-related decreases in tongue motor skills and masticatory performance were demonstrated by ultrasound observations and sieving methods.

Adult↗
PubMed1997

Application of the Center for Epidemiologic Studies Depression Scale among first-visit psychiatric patients: a new approach to improve its performance.

BACKGROUND: Although the Center for Epidemiologic Studies Depression Scale (CES-D) is an internationally popular self-rating scale for depression both in community and clinical settings, extant literature concerning its validity has several shortcomings. The present paper aimed to overcome these problems. METHODS: We applied newer assessment technology of receiver operating characteristics (ROC) analyses and stratum-specific likelihood ratios (SSLRs) and cross-validated the results in the 'training' and 'testing' data sets of 591 patients representing various clinical settings all over Japan. RESULTS: The ROC analyses demonstrated that the CES-D had moderate convergent and discriminant validity to detect major depressive episodes among first-visit psychiatric patients. Selecting single optimal cutoffs, however, failed to arrive at consistent results across various settings. The efficacy of the instrument was most conveniently transportable into clinical practices when converted into SSLRs, which were 0.35 (95% CI: 0.25-0.49) for the score range 0-29, 2.3 (1.8-3.1) for the score range 30-49, and 11.7 (3.1-44.0) for the scores above 50. In addition, the SSLRs proved to be generalizable not only across various clinical settings in our sample but also across psychiatric, primary care and community samples in the published reports. CONCLUSION: Clinicians and clinical epidemiologists can apply the SSLRs of the CES-D to various settings to estimate the probability of suffering from a major depressive episode in a convenient and intuitive manner.

Comorbidity↗
PubMed1997

Metastatic gastric lymph node rate is a significant prognostic factor for resectable stage IV stomach cancer.

BACKGROUND: Stage IV gastric carcinoma is rarely curatively resected and almost invariably carries a poor prognosis. Several clinicopathologic factors are involved, but lymphatic spread of the cancer may significantly affect survival. STUDY DESIGN: A retrospective study was designed to evaluate whether the nodal metastatic rate (number of lymph node metastases/number of resected lymph nodes) is a parameter of lymphatic spread and could provide a significant prognostic factor. Several prognostic factors were assessed by multivariate analysis in 153 stage IV gastric carcinoma patients with histopathologic data on nodal metastasis. RESULTS: A significant difference in survival was observed in the stage IV cancer patients with total nodal or gastric nodal metastatic rates < 50% versus those with rates > 50%. Multivariate analysis revealed that a total nodal or gastric nodal metastatic rate > 50% was a highly significant prognostic factor. The gastric nodal metastatic rate can be used in patients who do not undergo an extended lymphadenectomy. CONCLUSIONS: Lymphatic spread of gastric carcinoma expressed in terms of the total nodal or gastric nodal metastatic rate is a significant prognostic factor. The latter can be calculated without pathologic data derived from extended lymphadenectomy, and so it is universally applicable.

Humans↗
PubMed1997

Two-stage arterialized flow-through venous flap transfer for third-degree burn defects on the dorsum of the hand.

A modified, two-stage arteriovenous flow-through venous flap was designed to repair skin defects due to third-degree burns on the dorsum of the hand in four patients. Two weeks after plasty of an arteriovenous (A-V) shunt between the greater saphenous vein and dorsalis pedis artery, the arterialized flow-through venous flap was transferred using the greater saphenous vein as the pedicle. The size of the flaps utilized ranged from 7 x 13 cm to 9 x 13 cm. In three patients the entire flap survived without complication. In one patient whose flap had only one drainage vein, the flap survived with superficial necrosis of about 10 percent of the flap at the borders. During the 2 weeks after A-V shunt creation, the authors believe that microcirculation around the arterialized vein probably develops, contributing to better irrigation and thereby to flap survival. Using this two-stage procedure, it might be feasible to obtain larger grafts and to attain a higher flap survival rate.

Adult↗
PubMed1997

Variable tip angle slab selection pulses for carotid and cerebral time-of-flight MR angiography. Theory and experimental analysis.

OBJECTIVE: To determine the optimal parameters of variable tip angle slab selection (tilted optimized nonsaturating excitation, TONE) pulses in time-of-flight MR angiography, in order to produce the best visualization of vessels distal to the entry partition. MATERIAL AND METHODS: The influences of the mean flip angle (MFA) and the profile tilt of the TONE pulse in three-dimensional (3D) time-of-flight MR angiography were evaluated with a mathematical modeling of the flow signal amplitude. We compared the calculated flow signals with the signals from flow-phantom models and with those from 6 normal volunteers. 3D gradient echo images (TR/TE 30/7) were acquired with a single variable of the MFA and the profile tilt. The flow velocity of the phantom was maintained at 15 cm/s. Regions of interest were measured on the source images. We also evaluated the visualization of the cerebral vessels on maximum intensity projection images obtained with and without TONE pulses in 5 other healthy volunteers. RESULTS: The changes of flow signals in the phantom and in the volunteers were in good accord with those of the signals mathematically predicted and plotted by a computer, as each parameter was varied. The peripheral saturation was weaker at smaller MFA than at larger MFA. A greater profile tilt produced a more pronounced TONE effect than a lower one. The visualization of the peripheral cerebral vessels was markedly improved by the addition of the TONE pulse. CONCLUSION: Computer simulation is useful for examining the optimal TONE parameters. The TONE pulse markedly improves the visualization of the distal branches of the cerebral vessels.

Adult↗
PubMed1997

Lung cancer associated with Werner's syndrome: a case report and review of the literature.

A 52-year-old male had an abnormal shadow on a chest X-ray film. His parents were first cousins. His father, brother and two sisters had been diagnosed with Werner's syndrome. His lung lesion was diagnosed as lung cancer and right upper lobectomy was carried out. Histopathological examination of the resected specimen revealed bronchiolo-alveolar carcinoma with independent atypical adenomatous hyperplasia in the alveolar zone. The alveolar structures were those seen in aging lungs, suggesting a close relationship between Werner's syndrome and cancer development.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1997

A new macroscopic classification predicts prognosis for patient with liver metastases from colorectal cancer.

OBJECTIVE: The authors defined a new macroscopic classification of liver metastases from colorectal cancer. SUMMARY BACKGROUND DATA: There were different prognostic results after the same operative procedure for liver metastases with similar background factors. METHODS: Eighty-one resected liver metastases were classified into simple nodular (SN) or confluent nodular (CN) types according to the characteristics of the cut surface of the tumor. RESULTS: The 5-year survival rates after hepatectomy were 41.7% for the SN lesions (n = 39) and 23.1% for the CN lesions (n = 42). The difference between the survival curves was statistically significant (p = 0.0307). Multivariate analysis using Cox's proportional hazards model revealed that the macroscopic type (p = 0.023), the tumor diameter (p = 0.0001), and the presence of lymph node metastases (p = 0.0016) were statistically significant independent prognostic factors. CONCLUSION: The new macroscopic classification may be valuable as a prognostic factor reflecting the biologic behavior of liver metastases.

Colorectal Neoplasms↗
PubMed1997

Unusual masses found within ruptured silicone gel breast prostheses.

Imaging of breast implants has assumed more importance in medicine than ever before. Radiologists and surgeons alike have struggled to accurately identify folds in prostheses, rupture of prostheses, and migration of gel. Here we present two patients with an unusual presentation of masses within the gel of ruptured silicone gel-containing prostheses. In one instance, the mass was an organized hematoma. In the other, two round, calcified masses were found that we presume are hematomas that have become calcified over time. Radiologists and surgeons identifying spherical or ovoid masses seemingly within gel breast prostheses should entertain the possibility that the mass represents an organized hematoma and that the implant is ruptured.

Breast Implants↗