PubMed Health⌕ Search

Biomedical subjects

T Sakuma

Publications and source records attributed to T Sakuma.

At least 109 records · Page 6Linked to original sources
PubMed1996

[Assessment of a new TNM classification produced by UICC for resected lung cancer with intrapulmonary satellite tumor(s)].

We examined the efficacy of a new classification produced by International Union Against Cancer (UICC) in 1993 for 61 patients who underwent resection of lung cancer with intrapulmonary satellite tumor(s) during 1952 to June 1991. Survival rate after resection was calculated according to the new classification. Survival rate of patients with stage I lung cancer was 67% at four years after surgery, that with stage IIIA was 33% and stage IIIB 5% at five years after surgery. There was a significant difference between the survival of stage IIIA and stage IIIB. Five year survival of patients with N0 or N1 lung cancer was 62%, which was significantly better than four year survival (3%) with N2, N3, or NX lung cancer. Five year survival for patients with squamous cell carcinoma was 61%, which was significantly better than that (9%) with adenocarcinoma. The new TNM classification produced by UICC is acceptable in investigating lung cancer with ipsilateral satellite tumor(s). It is necessary to investigate lung cancer with contralateral satellite tumor(s). Prognosis of patients with N0 or N1 lung cancer, especially squamous cell carcinoma, even if with intrapulmonary satellite tumor(s), was relatively good after resection. Such lung cancers may be synchronous multiple lung cancers from a therapeutic point of view.

Adult↗
PubMed1995

Isolation and characterization of a new cDNA clone belonging to the cytochrome P450 2C gene subfamily in hamsters.

Cytochrome P450s are heme-containing proteins which evolved from an ancestral gene to form a large superfamily of enzymes. We previously isolated three distinct CYP2C cDNAs, namely CYP2C25, 2C26, and 2C27, from liver cDNA libraries of male and female Syrian hamsters. In the present study, we isolated another cDNA clone, assigned as CYP2C28, from the same male cDNA library. This cDNA consisted of 1556 nucleotides and encoded a polypeptide of 490 amino acids. CYP2C28 showed relatively low identities to other hamster CYP2C forms (71.4-72.6% in amino acid sequences) and showed the highest similarity to rat CYP2C24 (88.7%), while the other hamster CYP2C forms showed high similarities among themselves (> 90.2%). CYP2C28 protein expressed in yeast catalyzed the N-demethylation of aminopyrine and benzphetamine, but did not catalyze the hydroxylation of tolbutamide, testosterone, and progesterone. Northern blot analysis demonstrated that CYP2C28 mRNA was expressed in hamster livers 1 week after birth, when the other hamster CYP2C forms were not detectable. The level of CYP2C28 mRNA increased to 3 weeks and then decreased with time in males. The level in females was lower than that in males. In adult hamsters, CYP2C28 was induced almost threefold by administration of phenobarbital but not affected by 3-methycholanthrene. On the other hand, administration of pregnenolone 16 alpha-carbonitrile induced CYP2C28 in females but not in males. These results indicate that CYP2C28 is a unique form in the hamster CYP2C subfamily.

Amino Acid Sequence↗
PubMed1995

Solid Tubular Carcinoma of the Breast: MR Imaging and Pathologic Correlation.

PURPOSE: Solid tubular carcinoma of the breast is a recognizable histologic type of invasive ductal carcinoma, characterized by rare axillary lymph nodal metastases and a good prognosis. The purpose of this study is to describe the magnetic resonance (MR) characteristics of solid tubular carcinoma and to emphasize the spotty appearance on the MR subtraction images. MATERIALS AND METHODS: We reviewed the MR findings of seven patients with biopsy-proven solid tubular carcinoma. Two of the 7 cases were of the pure type (more than 85% solid tubular component) and the remaining 5 were of the mixed type (50% to 85% solid tubular component). The mean age of the patients was 56 years. RESULTS: The mean size of the lesions was 28 mm. On T1-weighted images four of the lesions were visible and three were not identified. After Gd-DTPA all the lesions were enhanced. On the subtraction images, g" popcorn" appearence areas were noted in the stained mass. CONCLUSION: Our preliminary results suggest that solid tubular carcinomas have a characteristic apperarence on the subtraction MR images.

Journal Article↗
PubMed1995

Effects of hypothermia and hyperpotassium on alveolar fluid clearance in the resected human lung.

The effect of hypothermia and hyperpotassium on alveolar fluid clearance in the resected human lung was examined by instilling an isosmotic albumin solution with a potassium concentration of 0.3 mEq/l or 20 mEq/l into one segment of a resected lobe within 10 min of surgical removal for bronchogenic carcinoma. The experiments were carried out at 37 degrees C, 25 degrees C, and and 8 degrees C over 4 hr, after which the alveolar fluid was aspirated. Alveolar fluid clearance was calculated by a simple equation using the changes in the albumin concentration of the alveolar fluid. It was found that although hypothermia at 8 degrees C abolished alveolar fluid clearance completely, alveolar fluid clearance at 25 degrees C was not different from that at 37 degrees C. Moreover, although the potassium concentration increased in the alveolar fluid at 37 degrees C and 8 degrees C, hyperpotassium did not affect the alveolar fluid clearance. These findings indicate that the net transport of potassium leans to influx from the alveolar epithelial cells into the alveolar spaces when the alveolar potassium concentration is low, and to efflux from the alveolar spaces when the alveolar potassium concentration is high. Thus, we conclude that hypothermia abolishes alveolar fluid clearance in resected human lungs, but that the potassium concentration in alveolar fluid does not affect alveolar fluid clearance.

Aged↗
PubMed1995

Hormonal regulation of the mRNA level of male-dominant cytochrome P450 (CYP2C27) in hamster livers.

Hormonal regulation in the expression of CYP2C27, a male-predominant form of cytochrome P450 in the hamster, was investigated. The mRNA level of CYP2C27 was five-fold higher in male than in female livers. The mRNA level was suppressed by both gonadectomy and hypophysectomy in male, while the mRNA level was increased by the same treatment in female, resulting in the disappearance of sex difference. In both sexes, treatment of the gonadectomized animals with testosterone induced the cytochrome over the level of sham- operated males. Treatment of the hypophysectomized animals with testosterone elevated the level in females. On the other hand, oestradiol did not show any effects on either the gonadectomized or the hypophysectomized animals of both sexes. Twice-daily injection of growth hormone to hypophysectomized animals restored the level in males. Continuous infusion of growth hormone to hypophysectomized animals suppressed the level in both sexes. These results indicate that the expression of CYP2C27 in hamsters is under the control of endocrine factors and suggest that the gonadal-pituitary axis pathway is a control mechanism as proposed in rats and mice.

Androgens↗
PubMed1995

An ultrasound biomicroscopic study of filtering blebs after mitomycin C trabeculectomy.

PURPOSES: To investigate the relation between filtering bleb function and ultrasound biomicroscopic images, and to establish a new classification system for filtering blebs according to these images. METHODS: After trabeculectomy with mitomycin C, the filtering blebs of 117 eyes from 117 patients with various types of glaucoma were examined using ultrasound biomicroscopy. Four parameters of the images-intrableb reflectivity, visibility of the route under the scleral flap, formation of a cavernous fluid-filled space, and bleb height-were correlated with the level of intraocular pressure (IOP). RESULTS: Reflectivity inside the bleb and visibility of a route under the scleral flap were highly associated with IOP control. Blebs were classified into four categories according to the four measured parameters: type L (low-reflective), type H (high-reflective), type E (encapsulated), and type F (flattened). Eyes with good IOP control had mainly type L blebs. Type E and type F blebs were seen mostly in eyes requiring additional medication. CONCLUSION: The structure inside a filtering bleb is visible by ultrasound biomicroscopy, and bleb function is significantly associated with its ultrasound biomicroscopic image in eyes trabeculectomized with adjunctive mitomycin C.

Adolescent↗
PubMed1995

Sequence-specific DNA recognition of the Escherichia coli Ada protein associated with the methylation-dependent functional switch for transcriptional regulation.

The Escherichia coli Ada protein, a suicidal DNA methyltransferase, is converted into a transcriptional regulator for methylation-resistance genes by the transfer of a methyl group from a DNA methylphosphotriester to its own Cys69 residue. Here, we report the DNA recognition mode and the functional switch mechanism of the N-terminal 16 kDa fragment of the Ada protein. NMR analysis has revealed that the segment from residues 102 to 123 forms a helix-turn-helix structure. A site-directed mutagenesis study has shown that the second helix in the helix-turn-helix structure plays a crucial role in specific recognition of DNA. These results imply that the sequence-specific interaction of the Ada protein with DNA occurs through the helix-turn-helix motif. NMR experiments on the methylated protein-DNA complex showed line broadening for the amide proton signals from the helix-turn-helix motif and for the protons in the vicinity of Cys69. In the case of the nonmethylated protein-DNA complex, signal broadening was observed only for protons from the helix-turn-helix. These findings suggest that the residues in the vicinity of Cys69 come into direct contact with the cognate DNA after methylation. We propose that the direct contact of this region is a major factor for the "switch" that converts the Ada protein from a nonspecific DNA binding form to a transcription factor.

Amino Acid Sequence↗
PubMed1995

Ceroid pigment deposition in circulating blood monocytes and T lymphocytes in Hermansky-Pudlak syndrome: an ultrastructural study.

An electron microscopic study of peripheral leukocytes obtained from a 39 year old woman with Hermansky-Pudlak syndrome was performed. Ceroid pigment granules were found within the lysosomes in 3.5% of monocytes and 5.4% of lymphocytes. Infrequently, pigment granules were also found in the parallel tubular arrays of lymphocytes. The lymphocytes containing ceroid pigment granules were confirmed to be T cells by immunoelectron microscopy. It was speculated that intralysosomal accumulation of ceroid pigment granules in Hermansky-Pudlak syndrome may be due to lysosomal dysfunction.

Adult↗
PubMed1995

Structural characteristic of splenic sinuses in idiopathic portal hypertension.

Splenic sinuses in idiopathic portal hypertension (IPH; 8 patients), liver cirrhosis (LC; 14 patients) and in regenerating autotransplanted spleens from 25 rats were compared with each other by scanning electron microscopy (SEM) and immunohistochemistry using antibodies against proliferating cell nuclear antigen (PCNA). Spleens obtained from six patients with gastric carcinoma and from five untreated adult rats were examined as controls. SEM of the sinuses showed that in IPH endothelial cells became irregular in shape, and the interendothelial slits of sinuses were irregularly enlarged. Sinus endothelial processes traversing the sinusal lumen were also found. The same changes were observed in the proliferating sinuses during regeneration of splenic tissue after autotransplantation in rats, but disappeared when the regeneration was completed. Irregular endothelial cells were few in LC. PCNA-positive sinus endothelial cells were increased in number in IPH as compared with those in LC; the mean number of PCNA-positive ones per cm2 was 45.4 in IPH and 8.2 in LC. It was suggested that, from SEM observation of sinus endothelial cells and counting PCNA-positive sinus endothelial cells, the sinuses of the spleen in IPH consist of proliferating endothelial cells or are in the state of increased proliferation. In conclusion, splenomegaly in IPH was presumed to be caused by proliferation of sinus endothelial cells, and by the increased splenic blood flow in the irregularly widened interendothelial slits of the sinuses.

Adult↗
PubMed1995

[Blood levels of cyclosporine, acute rejections and the prognosis of the allografts in pediatric renal allograft recipients].

BACKGROUND AND METHODS: Results of a total of 46 pediatric (mean age; 9.0 years), living-related, cyclosporine-treated renal allograft recipients were analyzed retrospectively to study 1), the effects of an acute rejection on the long-term allograft function and 2), the relationship between the cyclosporine blood levels and the frequency of acute rejections. In addition, sequential allograft biopsies (100 days, one, two and three years post-transplant) were performed in all cases to see if clinical symptoms correlated with histological changes. RESULTS: After a mean follow up of 3.3 (range 1-6) years, 15 of 22 (68%) recipients who had no signs of acute rejection, 6 of 12 (50%) who had acute rejections but responded completely to therapy, and none of the remaining 12 cases who failed to recover completely from acute rejections showed good allograft functions and normal histology on biopsy. Thirty-four of 46 cases had no clinical signs of rejection at 100-day allograft biopsy. Yet, histological changes compatible with acute rejection were noted in 11 of 34. Treatments of the rejection were promptly started on these patients and the prognosis was excellent in six cases. The mean blood trough levels of cyclosporine were significantly lower in patients who developed an acute rejection during the first week following transplantation as compared to those without rejection episodes during the same period, 165.5 ng/ml and 204.1 ng/ml, respectively. Furthermore, the mean blood cyclosporine trough levels in patients who experienced rejections during two, three and five weeks after transplantation were definitely lower than those who did not experience such episodes; 124.5 ng/ml, 101 ng/ml and 149.3 ng/ml versus 241.7 ng/ml, 217.7 ng/ml and 201.1 ng/ml respectively, although the number of the cases was too small to reach statistical significance. CONCLUSION: The results indicate that the long-term allograft function would depend on whether there were episodes of acute rejections, and/or how the allograft responded to the treatments. Since the introduction of cyclosporine has made it difficult to detect acute rejections by clinical findings alone such as blood chemistry or urinalysis, the role of routine allograft biopsies is very important in renal transplantation. It seems likely that low blood levels and/or acute decline of cyclosporine during early postransplant period could increase the possibility of episodes of acute rejection. Since it is well documented that cyclosporine induces less renal parenchymal damages in children, the blood through levels of the drug should be kept at between 200 and 300 ng/ml within 5 weeks of transplantation in order to reduce the risk of acute rejections and to improve the chance of long-term allograft survival.

Acute Disease↗
PubMed1995

[Assessment of nucleolar organizer regions (Ag-NORs) in bronchial dysplasia and roentgenographically occult bronchogenic squamous cell carcinoma].

Mean argyrophil nucleolar organizer regions (Ag-NORs) per nucleus were determined on columnar epithelium, bronchial dysplasia, roentgenographically occult squamous cell carcinoma and squamous cell carcinoma with roentgenographically findings in 76 formalin-fixed, paraffin-embedded resected specimens. 1) Mean Ag-NOR counts per nucleus (mean +/- standard deviation) were 1.67 +/- 0.30 in 10 columnar epitheliums, 2.74 +/- 0.41 in 13 lesions with bronchial dysplasia, 3.75 +/- 0.59 in 57 lesions with roentgenographically occult squamous cell carcinoma and 4.44 +/- 0.51 in 14 lesions with squamous cell carcinoma with roentgenographically findings. There were significant differences between each two groups. 2) In lesions with squamous call carcinoma, mean Ag-NOR counts per nucleus of T2, T3 or T4 tumor were significantly higher than those of T1 tumor. Mean Ag-NOR counts per nucleus of N1 or N2 tumor were significantly higher than those of N0 tumor.

Aged↗
PubMed1995

[MR imaging of infected spondylodiskitis: interval signal change in vertebral body (including enhanced image of vertebral body)].

A retrospective evaluation of MRI was carried out in 22 patients with spondylodiskitis. Low signal intensity on T1-weighted images and high or low signal intensity on T2-weighted images were observed. Sixteen patients underwent follow-up examinations after the initial examination. Various signal changes in the vertebral body were recognized. The longer the period of follow-up, the less abnormal the signal intensity became on both T1- and T2-weighted images. Several cases showed no change in signal intensity. In all of 17 patients re-examined after injection of Gd-DTPA, infected vertebral bodies were enhanced. We classified the enhancing patterns of infected vertebral bodies in three types: A) homogeneous, B) homogeneous with strong enhancement adjacent to the end plate, C) inhomogeneous. Pyogenic spondylodiskitis tended to show patterns A or B, and tuberculous spondylodiskitis pattern C. The enhancement effect disappeared after normalization or remission of laboratory findings. In two cases, the enhancement effect remained even after laboratory findings became normal. Contrast MRI was useful for understanding infectious state.

Adolescent↗
PubMed1995

[Observation of the chamber angle in primary angle-closure glaucoma with an ultrasound biomicroscope].

We observed the chamber angle in 47 eyes of 29 patients with primary angle-closure glaucoma using ultrasound biomicroscopy in dark and illuminated conditions. All observations were made before surgical intervention and without any drugs affecting pupillary reaction. Ultrasound biomicroscopy was repeated following laser iridotomy in 23 of the eyes. Out of 115 angle locations examined where no synechiae had been found by pressure gonioscopy, appositional angle closure was seen at 65 locations (57%) in 33 eyes (70%) in dark conditions. At 30 angle locations in 18 eyes, the appositional closure began in the vicinity of Schwalbe's line. After iridotomy, appositional closure was not observed even in dark conditions. Ultrasound biomicroscopy in dark conditions seems to be a promising procedure to visualize appositional angle closure in eyes with a narrow angle.

Aged↗
PubMed1995

Efficient complementary DNA directed expression of human fetal liver cytochrome P450 (CYP3A7) in insect cells using baculovirus.

CYP3A7 is a form of cytochrome P450, which is expressed specifically in human fetal livers. NPVHF1, a recombinant baculovirus containing the entire coding region of CYP3A7, was constructed and infected to Spodoptera frugiperda (Sf9) cells. Upon infection with NPVHF1, the Sf9 cells expressed the CYP3A7 to the maximum content of 0.2 nmol per mg of whole cell lysates 72 hours after infection. A 5.5-fold expression level (1.1 nmol per mg of whole cell lysates) was attainable when cultured in the presence of externally added hemin. A catalytic activity of the CYP3A7 expressed in the Sf9 cells was confirmed by the umu gene expression mutation assay, in which aflatoxin B1 was activated to a mutagen by the expressed CYP3A7 in the presence of NADPH-cytochrome P450 reductase and cytochrome b5. From these results, it is concluded that the baculovirus expression system enables the high-level expression of CYP3A7 and will be a very useful tool for the characterization of CYP3A7.

Aflatoxin B1↗
PubMed1995

[Neutrophil elastase in postoperative pleural effusion of patients who had undergone pulmonary resections].

We determined whether activity of neutrophil elastase increases in pleural effusion after lobectomy for the neoplasm in the lung. Samples of pleural effusion were obtained 3 and 24 h postoperatively and samples of the peripheral blood were obtained preoperatively, 3 h, 24 h, and 1 w postoperatively, then the neutrophil counts, the levels of neutrophil elastase and alpha 1-antitrypsin by enzyme-linked immunosorbent assay, the activity of neutrophil elastase using succinyl-(L-alanine) 3-p-nitroanilide were measured. We found that the levels of neutrophil elastase increased 170 times greater in pleural effusion than in peripheral blood 3 h after lobectomy. However, the levels of alpha 1-antitrypsin did not increase in pleural effusion. The activity of neutrophil elastase increased to 0.54 +/- 0.1 mumol/min/l in pleural effusion 3 h after lobectomy, however the activity of neutrophil elastase was under the sensitivity level of detection in the peripheral blood after lobectomy. In conclusion, there is an imbalance between the levels of neutrophil elastase and alpha 1-antitrypsin in pleural effusion after lobectomy, the imbalance resulting in the increased activity of neutrophil elastase which probably is relating to tissue injury in the pleural spaces.

Aged↗
PubMed1995

[Surgical treatment of lung cancer over 80 years of age: investigation from post operative complications].

Seventeen patients with lung cancer over 80 years were treated surgically from 1983 through 1993 in our department. Thirteen patients were male and four were female. The histology of the tumor was adenocarcinomas, squamous, large and small cell carcinomas, in 9, 6, 1 and 1 cases, respectively. More than single lobectomy was performed in each patient. Unilateral pulmonary occlusion test was applied in patients whose expected contralateral FEV1.0/BSA was less than 800 ml.m2, or expected residual FEV1.0/BSA was less than 850 ml.m-2. Postoperative cardiovascular complications, such as PAT, PAC, PVC or Af, were seen in 9 patients, respiratory problems, namely, sputa retention, retained secretions or atelectasis, in 7 patients. Blood chemistry and hematology were performed for about three weeks after operations, and found increases in serum transaminases, and leukocytosis. However, there were no operative death. We conclude that some patients over 80 years of age are candidates for surgery after careful cardiopulmonary preoperative evaluation.

Adenocarcinoma↗
PubMed1995

[Does nocturnal hypoxia relate to acute exacerbation of chronic respiratory failure with right heart failure in late sequelae of pulmonary tuberculosis?].

Thirty-eight patients with late sequelae of pulmonary tuberculosis (TB seq.) were studied to clarify whether or not nocturnal oxyhemoglobin desaturation (NOD) could relate to acute exacerbation of chronic respiratory failure (AE). All patients had been untreated with home oxygen therapy, because they were not severely hypoxic. We performed sleep studies, pulmonary function tests and arterial blood gas analysis and investigated past history about AE in each patient. Twelve patients had experienced AE with right heart failure and they were classified as CHF (congestive heart failure) group. The rest was classified as Non-CHF group. These two groups were compared as for each variables examined. There was no difference between the two groups in age, body weight, %VC, FEV1.0%, and awake PaO2. Awake PaCO2 was significantly higher in CHF group. Although no difference was observed in baseline SaO2, the degree of NOD was significantly greater in CHF group when evaluated by lowest SaO2 during sleep and 85% desaturation time (total time spent with SaO2 less than 85%). Moreover, 21 of Non-CHF and 6 of CHF were studied for cardiac parameters using right side cardiac catherization. While the differences of mean pulmonary arterial pressure and cardiac output between the two groups were not significant, pulmonary arteriolar resistance was higher in CHF group. We concluded that NOD in TB seq. had a major role in AE with right heart failure. We speculated that AE might be caused, at least partly, by pulmonary vasopressor response to recurrent NOD.

Acute Disease↗