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Biomedical subjects

M Monden

Publications and source records attributed to M Monden.

At least 271 records · Page 15Linked to original sources
PubMed1996

Separate analysis of nuclear and cytosolic Ca2+ concentrations in human umbilical vein endothelial cells.

Ca2+ concentration inside human umbilical vein endothelial cells was studied separately in cytosol and nucleus by a confocal laser scanning microscopy using fluo-3. The in vivo calibration curve for cytosol and nucleus showed good linearity between fluorescence intensity and Ca2+ concentration in cytosol ([Ca2+]i) and nuclei ([Ca2+]n). After calibration, [Ca2+]n was constantly higher than [Ca2+]i before and after the chelation of extracellular Ca2+ suggesting an active Ca2+ accumulation system on nuclear membrane. [Ca2+]n was also constantly higher than [Ca2+]i after the stimulation of thrombin (0.05 U/ml), FCS (10%), and thapsigargin (Tsg, 1 microM). The temporal change of [Ca2+]n and [Ca2+]i was identical, and [Ca2+]i gradient towards the nucleus and peripheral or central [Ca2+]n rise was observed after these stimulations. From these results, [Ca2+]n is not only regulated by the active Ca2+ accumulation system on nuclear membrane at rest but also the generation of inositol-triphosphate. FCS caused heterogeneous [Ca2+]n or [Ca2+]i rise from cell to cell; single spike or oscillatory change of [Ca2+]n and [Ca2+]i was observed in about 56% of cells, which were completely abolished by the chelation of extracellular Ca2+, suggesting that FCS stimulated [Ca2+]n and [Ca2+]i rise solely depending on Ca2+ influx from extracellular medium. The higher concentration of [Ca2+]n and heterogeneous [Ca2+]n rise may have important roles in nuclear-specific cellular responses.

Aniline Compounds↗
PubMed1996

Genetic mechanisms in esophageal carcinogenesis: frequent deletion of 3p and 17p in premalignant lesions.

Although dysplasia of the esophagus is thought to be the precursor lesion of esophageal squamous cell carcinoma (ESC), the sequence of genetic events during esophageal carcinogenesis is unclear. Using the polymerase chain reaction, we examined allelic losses at microsatellite loci in DNAs isolated from 106 lesions among 32 patients with ESC. Allelic losses on 3p or 17p occurred frequently even in dysplastic lesions (9 of 21 and 13 of 24 samples, respectively) including lesions with mild dysplasia (3p, 4 of 10 samples; 17p, 6 of 14 samples, respectively), and allelic losses on these chromosomal arms were also observed in cancerous tissues. We also detected allelic losses of the short and long arms of chromosome 9 at a low frequency in lesions with mild dysplasia and often in lesions with severe dysplasia and in intraepithelial cancers. Our results suggested that inactivation of tumor suppressor genes on 3p and 17p occurs at a very early stage of esophageal carcinogenesis and that genes on 9p and 9q are likely to play important roles in malignant changes. Comparison of the genetic alterations in precancerous dysplastic lesions with those in carcinomas supports the idea that ESC arises from the dysplastic lesion.

Alleles↗
PubMed1996

Decreased E-cadherin expression is associated with haematogenous recurrence and poor prognosis in patients with squamous cell carcinoma of the oesophagus.

Reduced expression of E-cadherin is associated with tumour invasiveness and metastasis. To elucidate whether E-cadherin expression correlates with clinical outcome in patients with oesophageal cancer, 62 patients were investigated immunohistochemically using an anti-E-cadherin monoclonal antibody (HECD-1). Eight patients had normal levels of expression in the tumour, 25 had tumours that expressed high levels (50 per cent or more tumour cells staining positive for E-cadherin) and 29 had tumours expressing low levels (less than 50 per cent of cells expressing E-cadherin). Patients with normally expressing tumours had a better prognosis at 3 years than those with low-expressing tumours (P < 0.05). Postoperative death was correlated significantly with lymphatic invasion, lymph node metastasis, E-cadherin expression and depth of invasion (P < 0.05). Furthermore, haematogenous recurrence was correlated with E-cadherin expression (rs = 0.38, P < 0.01) and blood vessel invasion (rs = 0.28, P < 0.05). These results suggest that evaluation of E-cadherin immunoreactivity may predict haematogenous recurrence and poor prognosis in patients with oesophageal cancer.

Adult↗
PubMed1996

The coagulofibrinolytic state of patients with primary varicose veins of the lower legs.

The relationship between a local hypercoagulable state and primary varicose veins of the lower legs was investigated by measuring the plasma levels of D-dimer (DD) and the thrombin-antithrombin-III complex (TAT) in 122 consecutive patients before treatment, and in 46 patients after surgical intervention and compression sclerotherapy. Elevated levels of DD and TAT were found in 25% and 20%, respectively, of the 122 patients, being significantly elevated in the patients with thrombophlebitis compared to the patients with no dermal symptoms, pigmentation, or stasis dermatitis. There was no significant difference in either parameter among eight groups of patients classified according to their valvular incompetence. The levels of DD and TAT were elevated before treatment in 25% and 20%, respectively, of 45 treated patients, but became significantly reduced after treatment. These results indicate that even though the local hypercoagulable state in varicose veins without thrombophlebitis is too subtle to be detected by systemic parameters such as DD and TAT, a local hypercoagulable state can be detected in a certain proportion of patients with venous stasis by these parameters.

Adult↗
PubMed1996

Plasma hepatocyte growth factor levels are increased in systemic inflammatory response syndrome.

Interleukin-1 (IL-1), a cytokine released from macrophages by endotoxin stimulation, has been shown to upregulate the genetic expression of the hepatocyte growth factor (HGF). The present study was conducted to determine whether plasma HGF is increased in patients with systemic inflammatory response syndrome (SIRS). The plasma levels of HGF, endotoxin, and beta-glucan were measured in 41 surgical patients without hepatic diseases, 18 of whom had been diagnosed with sepsis, and 33, with nonseptic SIRS. The plasma HGF was found to be significantly increased in the 18 patients with sepsis, at 0.69 +/- 0.47 ng/ml (mean +/- SD), and in the 23 patients with nonseptic SIRS, at 0.49 +/- 0.37 ng/ml, compared to values in 40 normal controls, at 0.10 +/- 0.03 ng/ml (P < 0.001). No significant correlations were observed between the plasma levels of HGF and endotoxin (r = 0.02) or beta-glucan (r = -0.05) in any of the patients; however, plasma HGF was significantly correlated with the WBC count (r = 0.34, P < 0.05) and with total bilirubin (r = 0.45, P < 0.01). Plasma HGF was also strongly correlated with alanine transaminase (ALT) in 8 patients with ALT levels higher than 50 U/l (r = 0.70), but there was no such correlation in 33 patients with ALT levels of 50 U/l or less (r = 0.30). Thus, although the clinicopathologic significance of HGF is not well understood, the present findings indicate that plasma HGF increases in response to infection or inflammation.

Digestive System Neoplasms↗
PubMed1996

A newly-designed shape-memory coil stent for esophageal stricture: a preliminary report.

A newly designed coil esophageal endoprosthesis was developed using a thermal shape-memory titanium-nickel alloy. The major advantages of this stent lie in (a) its small diameter while in its compressed state in ice water and (b) the large lumen which is achieved once it has been warmed to body temperature. The technical feasibility and tissue compatibility of this stent were tested on four beagle dogs: two with an anastomotic stricture and two with a stenosis induced by the injection of monoethanolamine oleate. The teflon-coated stent was inserted under fluoroscopy and removed 4 weeks after implantation. No signs of esophageal reobstruction were observed in any of the animals after implantation or extraction of the stent, although the dog which had received the first stent without teflon coating developed obstruction caused by granulation tissue. Our preliminary experience strongly suggests that the shape-memory alloy stent with teflon coating may be used in the endoscopic treatment of anastomotic stenosis after esophagectomy, as well as of esophageal obstruction caused by carcinoma.

Alloys↗
PubMed1996

Analysis of cytotoxic activity of the CD4+ T lymphocytes generated by local immunotherapy.

We previously reported that the anti-tumour effect of OK-432 is considerably enhanced by its intratumoral injection together with fibrinogen. In the present study, we generated killer T cells by culturing tumour-infiltrating lymphocytes from thyroid cancer patients who had received this local immunotherapy. Phenotypic analysis revealed that the T cells were positive for CD3+, CD4+, Leu8-, CD45RO+ and T-cell receptor (TCR)alpha beta+, as well as showing strong surface expression of HLA-DR, CD25, LFA-1 and ICAM-1. The generated CD4+ T cells secreted interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, TNF-beta, and interleukin (IL)-6 (but not IL-4), and exhibited a high level of cytolytic activity against several tumour cell lines. The cytolytic activity of these T cells for Daudi cells was inhibited by preincubation with an anti-intercellular adhesion molecule (ICAM)-1 antibody, but not by preincubation with anti-TCR alpha beta, anti-CD2, or anti-LFA-1 antibodies. Pretreatment with anti-ICAM-1 antibody inhibited T-cell cytolytic activity, but not conjugation with target cells. In addition, incubation with immobilised anti-ICAM-1 enhanced the secretion of IFN-gamma by T cells. We conclude that ICAM-1 expressed on the effector cytotoxic CD4+ T lymphocytes delivers regulatory signals that enhance IFN-gamma secretion.

Adjuvants, Immunologic↗
PubMed1996

Expression of p21 (WAF1/CIP1) protein in clinical thyroid tissues.

p21 (WAF1/CIP1) protein expression in various thyroid tissues, including thyroid carcinoma, was studied by means of immunohistochemistry using anti-p21 monoclonal antibody. Normal follicles and hyperplasias rarely expressed p21, whereas immunohistochemically positive cells were also too rarely found in follicular adenomas to justify these cases being classified as positive. Twenty eight of the 93 carcinomas examined (30.1%), however, were positive for p21. Of the p21-positive cases, 80% of the undifferentiated and 28.6% of the poorly differentiated carcinomas showed lesions co-expressing p21 and p53. If diffuse immunoreactivity of p53 reflects the p53 mutation, our results indicate that p21 in these carcinomas can be induced by p53-independent as well as by p53-dependent pathways. On the other hand, well-differentiated carcinomas did not co-express these two proteins and it therefore remains unclear whether p53-independent or p53-dependent pathways are predominant in this type of carcinoma. The incidence of expression of p21 was very similar in undifferentiated (26.3%), poorly (28.0%) and well-differentiated carcinomas (32.7%), even though they are characterised by different degree of malignancy. Furthermore, no correlation between p21 expression and either clinical parameters or patient's prognosis could be established. These results suggest that p21 is only marginally related to the characteristics of thyroid carcinoma and can play only an adjuvant role in regulating the progression of this carcinoma.

Antibodies, Monoclonal↗
PubMed1996

Calpain activation in plasma membrane bleb formation during tert-butyl hydroperoxide-induced rat hepatocyte injury.

BACKGROUND & AIMS: The mechanism of plasma membrane blebbing (dissociation of the lipid bilayer from the membrane cytoskeleton) in hepatocyte injury is not known. The aim of this study was to investigate the role of calpain, a calcium-dependent cytosolic protease, in bleb formation induced by oxidative stress. METHODS: Hepatocytes from Wistar rats were injured with tertbutyl hydroperoxide in the presence or absence of ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) or a specific calpain inhibitor, calpeptin (Z-Leu-nLeu-H). Bleb formation was examined by phase-contrast and transmission electron microscopies. Intracellular calcium concentration was measured using Fura-2. Western blot analyses were performed for cytoskeletal proteins (talin, alpha-actinin, and vinculin) and the intermediate (activated) and proactivated forms of calpain mu. RESULTS: tert-Butyl hydroperoxide induced a sustained increase in intracellular calciu, bleb formation, and, ultimately, hepatocyte death. Talin and alpha-actinin were degraded in a time-dependent manner, although no apparent changes of actin filament were observed. Before the cytoskeletal protein degradation, the intermediate form of calpain mu appeared as its proactivated form decreased. In addition, calpeptin or EGTA inhibited not only calpain mu activation but also cytoskeletal protein degradation and bleb formation. CONCLUSIONS: In tert-butyl hydroperoxide-treated hepatocytes, the activation of calpain promotes membrane blebbing via degradation of cytoskeletal proteins.

Animals↗
PubMed1996

Clonal analysis of precancerous lesion of hepatocellular carcinoma.

BACKGROUND & AIMS: It remains to be established whether precancerous lesion (dysplastic nodule) of hepatocellular carcinoma (HCC) is a neoplastic or hyperplastic lesion. Clonal analysis of this lesion was conducted to elucidate this important issue on histogenesis. METHODS: The method for clonal analysis was based on restriction fragment length polymorphism of the X chromosome-linked phosphoglycerokinase gene and on random inactivation of the gene by methylation. Clonal somatic mutations were also analyzed by DNA fingerprinting with two multilocus probes (33.6 and 33.15), and loss of heterozygosity was studied using five single-locus probes (MS1[1p33-p35], MS31[7p22-pter], MS43a[12q24.3-qter], MS8[5q35-qter], and g3[7q36-qter]). RESULTS: Clonal analysis by the phosphoglycerokinase gene-based method showed that all of the five dysplastic nodules and seven HCCs were monoclonal in origin. DNA fingerprinting showed clonal somatic mutations in six of 10 dysplastic nodules and in six of nine HCCs. Loss of heterozygosity was found in one dysplastic nodule (7p22-pter) and two HCCs (1p33-p35 and 12q24.3-qter). CONCLUSIONS: These results confirm monoclonality of HCC and show that hepatic precancerous lesion (dysplastic nodule) is not a hyperplastic but a neoplastic lesion, consisting of monoclonal cells with genetic alterations.

Aged↗
PubMed1996

Regulation mechanism of ERM (ezrin/radixin/moesin) protein/plasma membrane association: possible involvement of phosphatidylinositol turnover and Rho-dependent signaling pathway.

The ERM proteins, ezrin, radixin, and moesin, are involved in the actin filament/plasma membrane interaction as cross-linkers. CD44 has been identified as one of the major membrane binding partners for ERM proteins. To examine the CD44/ERM protein interaction in vitro, we produced mouse ezrin, radixin, moesin, and the glutathione-S-transferase (GST)/CD44 cytoplasmic domain fusion protein (GST-CD44cyt) by means of recombinant baculovirus infection, and constructed an in vitro assay for the binding between ERM proteins and the cytoplasmic domain of CD44. In this system, ERM proteins bound to GST-CD44cyt with high affinity (Kd of moesin was 9.3 +/- 1.6nM) at a low ionic strength, but with low affinity at a physiological ionic strength. However, in the presence of phosphoinositides (phosphatidylinositol [PI], phosphatidylinositol 4-monophosphate [4-PIP], and phosphatidylinositol 4.5-bisphosphate [4,5-PIP2]), ERM proteins bound with a relatively high affinity to GST-CD44cyt even at a physiological ionic strength: 4,5-PIP2 showed a marked effect (Kd of moesin in the presence of 4,5-PIP2 was 9.3 +/- 4.8 nM). Next, to examine the regulation mechanism of CD44/ERM interaction in vivo, we reexamined the immunoprecipitated CD44/ERM complex from BHK cells and found that it contains Rho-GDP dissociation inhibitor (GDI), a regulator of Rho GTPase. We then evaluated the involvement of Rho in the regulation of the CD44/ERM complex formation. When recombinant ERM proteins were added and incubated with lysates of cultured BHK cells followed by centrifugation, a portion of the recombinant ERM proteins was recovered in the insoluble fraction. This binding was enhanced by GTP gamma S and markedly suppressed by C3 toxin, a specific inhibitor of Rho, indicating that the GTP form of Rho in the lysate is required for this binding. A mAb specific for the cytoplasmic domain of CD44 also markedly suppressed this binding, identifying most of the binding partners for exogenous ERM proteins in the insoluble fraction as CD44. Consistent with this binding analysis, in living BHK cells treated with C3 toxin, most insoluble ERM proteins moved to soluble compartments in the cytoplasm, leaving CD44 free from ERM. These findings indicate that Rho regulates the CD44/ERM complex formation in vivo and that the phosphatidylinositol turnover may be involved in this regulation mechanism.

ADP Ribose Transferases↗
PubMed1996

Determination of the presence of interleukin-6 in bile after orthotopic liver transplantation. Its role in the diagnosis of acute rejection.

OBJECTIVE: The authors evaluated the significance of interleukin-6 (IL-6) in bile in the diagnosis of acute rejection after liver transplantation. SUMMARY BACKGROUND DATA: Interleukin-6 in blood has not been shown to be useful as a marker of acute rejection in clinical liver transplantation. In a rat liver transplantation model, the authors have found that bile IL-6 levels correlated well with the severity of rejection as determined histologically, whereas kinetics of serum IL-6 differed among rats without any definite feature related to graft rejection. METHODS: Fifty-one patients who underwent orthotopic liver transplantation between May 1990 and February 1991 at the University of California, Los Angeles, were included in the study. After liver transplantation, bile and blood were collected daily, and IL-6 levels were measured by the enzyme-linked immunosorbent assay. RESULTS: Bile IL-6 increased to 1228 +/- 317 pg/mL on the day of transplantation and decreased to 50 pg/mL or less within 48 hours. Patients who had uneventful postoperative courses had low levels of bile IL-6 throughout their hospitalization. In patients with acute rejection, bile IL-6 significantly increased (1090 +/- 990 pg/mL; p<0.05), but decreased in response to antirejection therapy. In patients who had liver dysfunction due to ischemic change or sepsis, bile IL-6 did not increase. Patients with cholangitis had significantly increased levels of bile IL-6 (146 +/- 47; p<0.05). Interleukin-6 in blood increased with many kinds of complications other than rejection and seemed to be less specific than that in bile. CONCLUSIONS: Measurement of IL-6 in bile may be a useful, noninvasive tool for diagnosing acute rejection.

Acute Disease↗
PubMed1996

Primary human fibroblasts induce diverse tumor invasiveness: involvement of HGF as an important paracrine factor.

Fibroblasts have been considered to play an important role in tumor progression. In order to evaluate the contribution of fibroblasts to tumor invasion, TE2-NS, an esophageal cancer cell line, was cultured on collagen gel containing primary fibroblasts derived from normal esophageal submucosa or cancerous tissues of seven esophageal cancer patients. TE2-NS showed diverse invasiveness into the underlying gel containing fibroblasts, but did not invade the gel not containing fibroblasts. The invasiveness of TE2-NS, which expressed hepatocyte growth factor (HGF) receptor, was well-correlated with the concentration of HGF in conditioned medium. Administration of neutralizing antibody against HGF effectively suppressed the invasion, but application of recombinant HGF without fibroblasts induced little invasion into the gel. Fibroblasts from non-cancerous tissue generally secreted a larger amount of HGF and induced tumor invasion to a greater extent than those from cancer tissue, with large diversity. Interestingly, HGF secretion of fibroblasts from non-cancerous tissue was stimulated by co-culture with TE2-NS in two lines, but not in the other four. These results indicate that HGF is an important paracrine factor which induces tumor cell invasion, and the diversity of HGF production by fibroblasts might suggest different potentiality to induce tumor invasion among patients.

Cadherins↗
PubMed1996

A prospective randomized trial of the preventive effect of pre-operative transcatheter arterial embolization against recurrence of hepatocellular carcinoma.

To clarify whether pre-operative transcatheter arterial embolization (TAE) improves survival after hepatectomy, a prospective randomized comparative study was done. Of a total of 115 registered patients having solitary hepatocellular carcinoma (HCC) 2 to 5 cm in diameter, 18 (15.7%) were excluded after randomization. As a result, 97 patients were chosen as subjects and divided into two groups: hepatectomy with (group A: n=50) and without (group B: n=47) pre-operative TAE. The period of observation of the patients who survived the surgery was between 4.0 and 6.6 years. The randomization appeared to have provided well-balanced groups of patients and the clinico-pathological characteristics of the two groups were quite similar. The necrotic part of the cancerous lesions, as confirmed by operative specimens, amounted to 74.8+/-33.4% (mean +/-SD) in group A and 6.8+/-7.2% in group B (P<0.01). However, the cancer-free survival rates after hepatectomy in both groups showed little difference (39.1+/-7.0 (%+/-SE) and 31.1+/-0.1, respectively). We speculate that TAE is not effective against such HCC accessory lesions as minute intrahepatic metastasis and tumor thrombus and that pre-operative TAE does not improve post-operative survival.

Adult↗
PubMed1996

Role of interleukin-6 in skeletal muscle protein breakdown and cathepsin activity in vivo.

In order to elucidate the acute and chronic effects of interleukin-6 (IL-6) on muscle protein degradation, the weight of skeletal muscles and the activities of lysosomal cathepsins (B and L) in the muscles were examined in two animal models. Two intraperitoneal injections of recombinant human IL-6 into rats did neither significantly affect the cathepsin activities in the soleus and the extensor digitorum longus muscles nor the weight of these muscles. On the other hand, the gastrocnemius muscles of the IL-6 transgenic mice underwent severe atrophy accompanied by a marked increase in cathepsin activities. We conclude that IL-6 mediates muscle protein degradation with enhancing lysosomal cathepsin activity, and that these muscle reactions are mandated by chronic exposure to a high level of IL-6.

Animals↗
PubMed1996

3DFT-flash MR imaging of pancreatic cancer with gadopentetate dimeglumine.

PURPOSE: We evaluated the usefulness of dynamic 3-dimensional Fourier transformation (3DFT) fast low angle shot (FLASH) MR imaging using gadopentetate dimeglumine (Gd-DTPA) to assess the extent of pancreatic cancer. MATERIAL AND METHODS: Breath-hold 3DFT-FLASH MR images (20/4; 25 degrees flip angle; 7 partitions; 3-5-mm slice thickness) were obtained before the ++administration of 0.1 mmol/kg of Gd-DTPA, just after (early phase), and 1 and 2 min (late phases) after in 14 patients with pancreatic cancer. All patients underwent surgical removal or laparotomy. We compared the findings of T1-, T2-, and postcontrast T1-weighted spin-echo (conventional SE) and 3DFT-FLASH imaging with histologic or surgical findings. RESULTS: Dynamic MR images could delineate the pancreatic tumors more clearly than the conventional SE images, and were useful for diagnosing vessel invasion. The contrast-to-noise ratio between the pancreatic cancer and the surrounding pancreatic parenchyma was significantly higher with the dynamic 3DFT-FLASH image than with the conventional SE images (p<0.01). CONCLUSION: Dynamic 3DFT-FLASH MR imaging with Gd-DTPA is useful in delineating and evaluating the extent of pancreatic cancer.

Adult↗
PubMed1996

Investigation of the oxytocin receptor expression in human breast cancer tissue using newly established monoclonal antibodies.

The expression of the oxytocin (OT) receptor (OTR) in breast cancer was studied using newly established anti-OTR monoclonal antibodies. Immunoblotting indicated that the antibody 2F8 recognized a 70K OTR in the pregnant myometrium and breast cancer tissue. Among 57 breast cancer patients, we detected OTR immunoreactivity in 52 (91.2%) by immunohistochemistry using 2F8. Using another monoclonal antibody for different receptor domains, 1-2, the staining profile was identical in all positive samples. Of 52 OTR-positive samples, 28 were diffusely positive (> 80% of cancer cells were stained), and 24 were partially positive (< 80% cells were stained). The ratio of estrogen receptor-positive samples was slightly higher among those that were diffusely positive, but there was no apparent relationship between OTR expression and other clinical parameters. We also confirmed the expression of the OTR in positively stained samples by means of Northern blotting and RT-PCR at the transcription level. The OTR messenger RNA and RT-PCR product were the same size as those in the pregnant myometrium. We also determined the expression of the OTR using flow cytometry in four breast cancer cell lines (MCF-7, MDA-MB-231, MDA-MB-361, and MDA-MB-468). However, OT had no significant effect on their growth during a short period (7 days) of culture. These findings indicated that the OTR is expressed in breast cancer derived not from the myoepithelium but from the glandular or ductal epithelium; however, the biological function of OT in breast cancer remains to be determined.

Adult↗