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Biomedical subjects

M Suzuki

Publications and source records attributed to M Suzuki.

At least 163 records · Page 9Linked to original sources
PubMed2002

Cellular component of vascular calcification. Fibroblasts are essential for calcium deposition in cultured cells.

It has been reported that calcium deposition and calcium content in cultured human aortic smooth muscle cells (SMC) increased when the cells are incubated in a medium with a high phosphate concentration (2 mM). To determine the cellular components or soluble factors contributing to the deposition, we cultured commercially available SMC, fibroblasts (Fb) and endothelial cells (Ed). These cells and their mixtures were incubated for 10 days in normal or high-phosphate media. Calcium crystals were stained by the von-Kossa staining and counted in the defined area. Calcium content was measured by a colorimetric assay. SMC were incubated in high-phosphate media (up to 2 mM) or beta-glycerophosphate (beta-GP) media, resulting in no obvious deposition of calcium crystals, irrespective of the coating of type I collagen on the dish. Next, various combinations of cells were cultured, and a significant number of depositions were observed only when Fb were included in the combination. The calcium content was significantly higher in cultures of SMC and Fb. The calcium deposition on single or mixture of the cells did not increase compared with control when cells were incubated in a high concentration of phosphate, cultured in the existence of beta-GP or uremic serum. We therefore conclude that Fb, rather than SMC or Ed, are essential for calcium deposition and calcium accumulation in culture. Phosphate concentration in the medium and uremic serum did not influence the deposition of calcium.

Calcification, Physiologic↗
PubMed2002

Production of cartilage link protein by human granulosa-lutein cells.

Link protein (LP), an extracellular matrix protein in cartilage, stabilizes aggregates of hyaluronic acid (HA) and proteoglycans, including aggrecan and inter-alpha-trypsin inhibitor (ITI). We have shown previously that cartilage LP is present in the maturing rat and mouse ovary. In the present study, we have employed immunohistochemistry to examine the anatomical distribution of cartilage LP in the human ovary. The expression of cartilage LP was selectively detected in the cells within the granulosa compartment of the preovulatory dominant follicle. The HA-positive granulosa-lutein cells were found to be a cartilage LP-positive subpopulation. We subsequently studied the in vitro expression of cartilage LP in cultured human granulosa-lutein cells obtained at oocyte retrieval for in vitro fertilization. Analysis of cultured cells by enzyme-linked immunoaffinity assay, Western blotting and immunofluorescence microscopy revealed that gonadotropin stimulates cartilage LP production. Time-course studies indicated that the cartilage LP production was induced as early as with gonadotropin stimulation for 2 h, and the effect was sustained up to 8 h. Western blot analysis further revealed the presence of the macroaggregates composed of HA, ITI and cartilage LP in the gonadotropin-stimulated granulosa-lutein cell extracts. Collectively, the present results raise the possibility that cartilage LP forms extracellular structures that may have a regulatory function in the developing follicle in the human ovary.

Adult↗
PubMed2002

Transforming growth factor-beta gene polymorphism in sarcoidosis and tuberculosis patients.

SETTING: Transforming growth factor-beta (TGF-beta) plays an important role in many diseases, influencing as it does such processes as immune responses, fibrosing processes, and angiogenesis. Recently, polymorphisms have been described for TGF-beta that are associated with the risk of several diseases. In this study, we investigated whether TGF-beta 1 polymorphism has an effect on sarcoidosis and tuberculosis. OBJECTIVE: TGF-beta 1 Codon 10 T869C polymorphism was investigated in 110 healthy control subjects, 104 sarcoidosis patients, and 101 tuberculosis patients. DESIGN: The TGF-beta genotype was determined using polymerase chain reaction restriction fragment length polymorphism. RESULTS: We found no significant differences in TGF-beta genotypes between sarcoidosis patients and healthy controls or tuberculosis patients and controls. The long axis of the tuberculin skin test was larger in the CC type compared with the CT type. However, there was no association between the TGF-beta genotype and the roentgenographic stage, the disappearance of shadows, or organ involvement in sarcoidosis, nor any association between genotype, the extent or type of roentgenographic shadow, or detected volume of tubercle bacilli in tuberculosis. CONCLUSION: From the results, we believe that TGF-beta polymorphisms on the whole do not have a strong influence on disease onset or clinical progression in sarcoidosis and tuberculosis, although this polymorphism might have an effect on the immune response in a tuberculosis host.

Adult↗
PubMed2002

Bronchopleural fistula after lung cancer surgery. Multivariate analysis of risk factors.

BACKGROUND: To elucidate retrospectively the risk factors for bronchopleural fistulae after lung cancer surgery. METHODS: The subjects were 1,177 patients with lung cancer who underwent surgery between 1983 and 1997. Twenty-two clinical factors were examined by logistic analysis. RESULTS: Bronchopleural fistulae were observed in 35 patients (32 males, 3 females) with a mean age of 64 years. Eighteen (51%) of 35 patients died of BPF-related complications. The significant risk factors obtained by univariate analysis were male gender, heavy smoking, current smoking, low level of %FVC, metastases to lymph nodes, squamous cell carcinoma, increased WBC, decreased albumin, advanced postsurgical stage, sleeve lobectomy, and resection of the right lower lobe or middle and lower lobe. The significant risk factors noted by multivariate analysis were heavy smoking (30 or more pack/years), current rather than past smoking, metastases to lymph nodes, decreased albumin (3.5 mg/dl or less), and resection of the right lower lobe or middle and lower lobe. CONCLUSIONS: The above risk factors must be taken into account before surgical techniques followed by adequate perioperative management are selected.

Adolescent↗
PubMed2002

[Long-term results of the operation for the aortic arch aneurysm].

Between October, 1991, and October, 2001, 60 patients underwent aortic arch replacement with or without an aortic arch branched graft for atherosclerotic arch aneurysms. Their mean age was 70.1 +/- 8.6 years. Eight (13.3%) patients were operated on an emergency basis because of rupture or impending rupture of aneurysms. All operations were performed with hypothermic extracorporeal circulation. Selective cerebral perfusion for cerebral protection during aortic arch repair and systemic circulatory arrest during distal graft anastomosis was used in 56 patients. Mean selective cerebral perfusion time was 86.1 +/- 12.1 minutes. A total of 14 concomitant procedures were done. Overall in-hospital mortality was 3.3%. Postoperative temporary and permanent neurologic dysfunction were 1.6% and 1.6%. Long-term follow-up was 100% complete. There were 6 late deaths with the cumulative survival rate was 74.6 +/- 8.8%. A subsequent aortic operation was necessary for the treatment of an aortic abnormality distal to the arch in 6 patients. Reoperation free rate was 85.2 +/- 5.8%. In conclusion, cerebral protective effect of antegrade selective cerebral perfusion and total arch replacement with an aortic arch branched graft could substantially reduce in-hospital mortality and postoperative neurologic dysfunction and a satisfactory long-term results could be obtain in patients with atherosclerotic arch aneurysms.

Aged↗
PubMed2002

Peripheral pulmonary atelectasis and oxygentation impairment following coronary artery bypass grafting.

BACKGROUND: Severe pulmonary oxygenation impairment occurred in some patients with pleurotomy during the harvest of the internal mammary artery graft followed by coronary artery bypass grafting (CABG). Peripheral pulmonary atelectasis in the postoperative chest X-ray was detected in these patients. We studied the efficacy of intraoperative positive end-expiratory airway pressure (PEEP) therapy for the prevention of postoperative pulmonary oxygenation impairment. METHODS: The pleural cavity was intraoperatively opened in 40 patients with solitary CABG procedure performed during 5 years since January 1992. These patients were divided into two groups. Intraoperative PEEP therapy, which is initiated just after pleurotomy, was not used in 32 patients before May, 1996 (control group) and used for recent 8 patients with pleurotomy (PEEP group). The mean age of patients was 60 years old in the control group and 68 in the PEEP group. RESULTS: Respiratory insufficiency (A-aDO2 >400 mmHg and RI >1.5) was detected in 6 patients in the control group. Three out of these 6 patients required long-term mechanical respiratory support over a week. No respiratory insufficiency occurred in patients of the PEEP group. Values of PaO2, A-aDO2, respiratory index and shunt ratio were significantly worse in the control group than in the PEEP group. CONCLUSIONS: In conclusion, PEEP therapy may prevent pulmonary atelectasis and oxygen impairment after CABG.

Aged↗
PubMed2002

[Cardiovascular surgery in patients with Marfan syndrome].

The natural history of patients with Marfan syndrome is depressing, however, cardiovascular surgery can improve the prognosis. We reviewed the results of this surgical procedure for 10 years. Fourteen Marfan patients underwent cardiovascular surgery for a total of 21 times. Hospital mortality was 4.8% (1 case died on the 105th day after entire thoraco-abdominal aortic replacement because of pyothorax and sepsis), and the 5- and 10-year Kaplan-Meier survival was 92.9% and 77.4% respectively. Reoperation free rate was 51.4% and 38.6% respectively. Cardiovascular surgery in Marfan syndrome can be performed with good result. Aggressive surgical management and close follow-up of patients who undergo surgery is important.

Acute Disease↗
PubMed2002

[Angiosarcoma arised from a solitary schwannoma of the chest wall].

Angiosarcomas rarely develop within a peripheral nerve or a peripheral nerve sheath tumor. A 68-year-old woman was admitted for right hemothorax. She had suffered from the left thoracic empyema and the right chest wall tumor which had been regarded as schwannoma clinically. Anemia got serious due to continuous bloody effusion. Although bleeding point was not detected by thoracotomy. The right chest wall tumor was resected. Postoperatively bloody effusion still drained continuously, she died ten days after the operation. Resected tumor was almost necrotized. The tumor was diagnosed as angiosarcoma pathologically, in which a part of schwannoma component resided. It is indicated that angiosarcoma in this case arised from degenerated schwannoma. It is necessary to consider angiosarcoma, rarely arised from degenerated schwannoma, during conservative, long-term observation on the care of schwannoma.

Aged↗
PubMed2002

Catalytic ozonation of an organophosphorus pesticide using microporous silicate and its effect on total toxicity reduction.

Catalytic ozonation is promising as one of the advanced oxidation processes because of its effective use of ozone and its improved treatability of organic compounds through radical reactions. In this article, we investigated the feasibility of microporous silicates as a potential catalyst for a catalytic ozonation process. Organophosphorus insecticide, dichlorvos (DDVP), was employed as a model chemical for assessing conventional ozonation and catalytic ozonation, because its oxidative intermediate is toxic and is not degraded by direct ozonation. It was found that ozone was well adsorbed and simultaneously decomposed in microporous silicates, resulting in the production of possible radical species. In the presence of microporous silicates, radical reactions by decomposed ozone were evidenced by phosphate ion release that shows a degradation of a toxic intermediate of DDVP. Accordingly, cytotoxicity was successfully decreased. In a continuous treatment process combining a conventional ozonation vessel and a microporous silicate column for an effective use of residual ozone, enhanced degradation of DDVP was demonstrated by a decrease of DOC, an increase of the PO4(3-) concentration and reduction in the cytotoxicity. This new treatment mechanism is likely to be promising as an advanced water treatment process particularly when we think about better toxicity reduction of wastewaters.

Adsorption↗
PubMed2002

Preservation of human cell bioassay device for the on-site evaluation of environmental waters.

We have already developed a novel disposable bioassay device based on the low-density lipoprotein (LDL) uptaking activity of human hepatoblastoma Hep G2 cells in our previous work. However, this device is not readily applicable to evaluate river water toxicity on-site because it cannot be preserved for more than one week. In this work, we developed the method for preservation of the device to enable it to be preserved for at least one month. The device can be supplied to individual environmental sites without any facilities for cell culture. We can evaluate river water toxicity by 2 hours of exposure after thawing. Therefore, this kind of device could be a promising tool for daily water quality management.

Biological Assay↗
PubMed2001

Problems with peritoneal cytology in second-look laparotomy performed in patients with epithelial ovarian carcinoma.

BACKGROUND: The recurrence rate of ovarian carcinoma is high even when a second-look laparotomy (SLL) is negative. In the current study, the accuracy of peritoneal cytology as an evaluation method of SLL was examined. METHODS: The positive SLL rate and the diagnostic accuracy of peritoneal cytology were evaluated in 101 patients with epithelial ovarian carcinoma. RESULTS: Twenty-three of the 101 patients (23%) were positive based on SLL. The factors considered to be high risk factors for a positive SLL were advanced disease (Stages III and IV by the International Federation of Gynecology and Obstetrics [FIGO] classification), serous adenocarcinoma, and maximum residual tumor > 2 cm after primary surgery (P < 0.05). Of the 23 patients found to be positive on SLL, peritoneal cytology was positive in 6 patients, in whom the percentage was low (26%). The remaining 17 patients (74%) demonstrated false-negative cytology. Of these 17 patients, the tumor tissues were found to be capsulated completely with connective tissues in all biopsy specimens from 9 patients (53%) and in all but 1 biopsy specimen in 6 patients (35%), together accounting for a capsulation rate of 88%. Conversely, clear exposure of the tumor tissues was observed in at least two biopsy specimens in those patients demonstrating positive cytology (P < 0.01). CONCLUSIONS: Peritoneal cytology in SLL was found to result in a high false-negative rate. One of the reasons for this was considered to be capsulation of the lesions with proliferated connective tissues, which may have been the result of by chemotherapy.

Adult↗
PubMed2001

Transfection of young guinea pig vestibular cells in vitro with an adenovirus vector.

This study shows distributions of lacZ-positive cells in the vestibular labyrinthine explants of young guinea pigs with mature ears. When adenovirus lacZ vectors were administered to the vestibular labyrinth following removal of the otoconial membrane, lacZ-positive cells were observed in the mesothelial cells in the perilymphatic space, in the sensory and supporting cells in the utricle and ampulla, and in the transitional and dark cells in the ampulla. When the otoconial membrane was preserved, lacZ-positive cells were not distributed in the utricular sensory epithelium. These findings suggest that adenovirus vectors can transform a variety of vestibular epithelial cells, but that it is difficult for adenovirus vectors to pass through the otoconial membrane.

Adenoviridae↗
PubMed2001

Radiation risk to low fluences of alpha particles may be greater than we thought.

Based principally on the cancer incidence found in survivors of the atomic bombs dropped in Hiroshima and Nagasaki, the International Commission on Radiation Protection (ICRP) and the United States National Council on Radiation Protection and Measurements (NCRP) have recommended that estimates of cancer risk for low dose exposure be extrapolated from higher doses by using a linear, no-threshold model. This recommendation is based on the dogma that the DNA of the nucleus is the main target for radiation-induced genotoxicity and, as fewer cells are directly damaged, the deleterious effects of radiation proportionally decline. In this paper, we used a precision microbeam to target an exact fraction (either 100% or < or =20%) of the cells in a confluent population and irradiated their nuclei with exactly one alpha particle each. We found that the frequencies of induced mutations and chromosomal changes in populations where some known fractions of nuclei were hit are consistent with non-hit cells contributing significantly to the response. In fact, irradiation of 10% of a confluent mammalian cell population with a single alpha particle per cell results in a mutant yield similar to that observed when all of the cells in the population are irradiated. This effect was significantly eliminated in cells pretreated with a 1 mM dose of octanol, which inhibits gap junction-mediated intercellular communication, or in cells carrying a dominant negative connexin 43 vector. The data imply that the relevant target for radiation mutagenesis is larger than an individual cell and suggest a need to reconsider the validity of the linear extrapolation in making risk estimates for low dose, high linear-energy-transfer (LET) radiation exposure.

Alpha Particles↗
PubMed2001

Evaluation of apoptosis and micronucleation induced by reactor neutron beams with two different cadmium ratios in total and quiescent cell populations within solid tumors.

PURPOSE: Response of quiescent (Q) and total tumor cells in solid tumors to reactor neutron beam irradiation with two different cadmium (Cd) ratios was examined in terms of micronucleus (MN) frequency and apoptosis frequency, using four different tumor cell lines. METHODS AND MATERIALS: C57BL mice bearing EL4 tumors, C3H/He mice bearing SCC VII or FM3A tumors, and Balb/c mice bearing EMT6/KU tumors received 5-bromo-2'-deoxyuridine (BrdU) continuously for 5 days via implanted mini-osmotic pumps to label all proliferating (P) cells. Thirty min after i.p. injection of sodium borocaptate-10B (BSH), or 3 h after oral administration of p-boronophenylalanine-10B (BPA), the tumors were irradiated with neutron beams. The tumors without 10B-compound administration were irradiated with neutron beams or gamma-rays. This neutron beam irradiation was performed using neutrons with two different Cd ratios. The tumors were then excised, minced, and trypsinized. The tumor cell suspensions thus obtained were incubated with cytochalasin-B (a cytokinesis blocker), and the MN frequency in cells without BrdU labeling (=Q cells) was determined using immunofluorescence staining for BrdU. Meanwhile, for apoptosis assay, 6 h after irradiation, tumor cell suspensions obtained in the same manner were fixed, and the apoptosis frequency in Q cells was also determined with immunofluorescence staining for BrdU. The MN and apoptosis frequencies in total (P + Q) tumor cells were determined from the tumors that were not pretreated with BrdU. RESULTS: Without 10B-compounds, the sensitivity difference between total and Q cells was reduced by neutron beam irradiation. Under our particular neutron beam irradiation condition, relative biological effectiveness (RBE) of neutrons was larger in Q cells than in total cells, and the RBE values were larger for low Cd-ratio than high Cd-ratio neutrons. With 10B-compounds, both frequencies were increased for each cell population, especially for total cells. BPA increased both frequencies for total cells more than BSH did. Nevertheless, the sensitivity of Q cells treated with BPA was lower than that of Q cells treated with BSH. Whether based on the MN frequency or the apoptosis frequency, similar results concerning the sensitivity difference between total and Q cells, the values of RBE, and the enhancement effect by the use of 10B-compound were obtained. CONCLUSION: Apoptosis frequency, as well as the MN frequency, can be applied to our method for measuring the Q cell response to reactor neutron beam irradiation within solid tumor in which the ratio of apoptosis to total cell death is relatively high, as in EL4 tumor. The absolute radiation dose required to achieve the same endpoint for Q cells is much higher than that for total cells when combined with 10B-compound, especially with BPA.

Animals↗
PubMed2001

Age-dependent impairment of delay and trace eyeblink conditioning in mice.

The age effect on classical eyeblink conditioning in unrestrained mice (C57BL/6J strain) was evaluated. Mice were trained at one of three age periods (8, 45-50 or 85-90 weeks). In the delay paradigm, significant learning deficits were evident in the 85-90 week-old group, but no deficits were observed in the behavior of the 45-50 week-old group. On the other hand, in the trace paradigm with a stimulus-free trace interval of 500 ms, significant deficits became apparent at the age of 45-50 weeks. These results indicate that trace eyeblink conditioning is more susceptible to age-related deterioration of memory in mice than delay eyeblink conditioning.

Aging↗