Biomedical subjects

K Taguchi

Publications and source records attributed to K Taguchi.

At least 19 recordsLinked to original sources

PubMed2006

Ca channel currents inhibited by serum from select patients with Guillain-Barré syndrome.

We performed an electrophysiological study demonstrating inhibition of spontaneous muscle action potentials within a coculture of rat muscle and spinal cord by exposure to serum, as well as purified IgG, from patients with the acute motor axonal neuropathy (AMAN) variant of Guillain-Barré syndrome (GBS). However, exposure to serum from two patients with the acute inflammatory demyelinating polyneuropathy (AIDP) form of GBS had no effect. Using a whole-cell recording technique, we then investigated the effects of serum and purified IgG from patients with GBS on voltage-dependent calcium channel (VDCC) currents in nerve growth factor-differentiated PC12 cells. Serum from patients with GBS (AMAN) inhibited VDCC currents in PC12 cells, which was fully reversible by washing with the bath solution. Similarly, purified IgG from the serum of two patients with GBS (AMAN) also inhibited VDCC currents in PC12 cells. In contrast, sera from patients with AIDP and healthy volunteers did not affect VDCC currents in PC12 cells. These results suggest that muscle weakness in some patients with GBS might be induced by inhibition of Ca2+ channel currents within motor nerve terminals.

Action Potentials↗

PubMed2006

Contaminated oral intubation equipment associated with an outbreak of carbapenem-resistant Pseudomonas in an intensive care unit.

Twenty intensive care patients were diagnosed as infected or colonized by Pseudomonas aeruginosa within a one-month period; a rate three to four times higher than the typical background frequency of this infection in the intensive care unit (ICU). Patients with positive respiratory specimens were mechanically ventilated, which included re-used disinfected bite blocks during intubation. Fourteen specimens from 20 positive patients originated in the respiratory tract. Seven clonal variants were isolated and identified as originating from the same strain by pulsed-field analysis. These isolates were also matched to the strain detected on the re-used bite blocks, which had been disinfected with 140ppm sodium hydrochloride. Notably, Staphylococcus aureus was also detected on bite blocks sterilized with ethylene dioxide, indicating incomplete disinfection. In immunocompromised patients, re-use of bite blocks during intubation must be prohibited. Single-use kits or intubation without the use of bite blocks is recommended.

Carbapenems↗

PubMed2006

Involvement of brain protein kinase C in nitrous oxide-induced antinociception in mice.

Exposure of mice to the anesthetic gas nitrous oxide (N(2)O) produces a marked antinociceptive effect. Protein kinase C is a key regulatory enzyme that may be targeted by general anesthetics. However, a relationship between N(2)O-induced antinociception and protein kinase C has yet to be established. The present study was conducted to identify whether protein kinase C might influence N(2)O-induced antinociception in mice. Regular exposure (11 min) to N(2)O produced concentration-dependent antinociception in mice, as determined using the abdominal constriction test. N(2)O-induced antinociception was attenuated by i.c.v. pretreatment with phorbol 12,13-dibutyrate, a protein kinase C activator. This phorbol 12,13-dibutyrate antagonism of N(2)O-induced antinociception was reversed by i.c.v. pretreatment with calphostin C, a protein kinase C inhibitor. Long-term exposure (41 min in total, including 30 min prior to, and 11 min of analgesic testing) to 70% N(2)O produced reduced analgesic effects, compared with regular exposure to 70% N(2)O, thus indicating acute tolerance to N(2)O-induced antinociception. However, mice pretreated with calphostin C, chelerythrine, which is another protein kinase C inhibitor, and phorbol 12,13-dibutyrate, did not develop acute tolerance. Regarding activation of protein kinase C, regular exposure to 70% N(2)O did not increase protein kinase C within the membrane fraction of brain tissue, as determined by immunoblot analysis, but long-term exposure to 70% N(2)O did. The i.c.v. pretreatment with calphostin C and phorbol 12,13-dibutyrate prevented the increase in protein kinase C observed with long-term exposure to 70% N(2)O. These results suggest that brain protein kinase C negatively regulates the antinociceptive effect of N(2)O, and that activation of brain protein kinase C is related to the development of acute tolerance to N(2)O-induced antinociception in mice.

Analgesics↗

PubMed2006

Management of childhood and adolescent thyroid carcinoma: long-term follow-up and clinical characteristics.

AIM: This analysis was performed to evaluate clinical factors such as local tumor control, control of distant metastasis, survival, and complications in children and adolescents with thyroid carcinoma. MATERIALS AND METHODS: From 1960 to 2003, 21 children and adolescents (16 girls and 5 boys, aged 4 to 15 years) were treated for thyroid carcinoma in our departments. Clinical data, operative findings, pathological findings, operative procedures, intra- and postoperative complications and follow-up were evaluated. Follow-up of patients ranged from 3 to 42 years (median, 20 years). RESULTS: Papillary carcinoma was found in 20 patients (95%) and follicular carcinoma in one patient. Cervical lymph node metastases were found in 12 out of 21 patients (57.1%) when thyroid carcinoma was diagnosed, and 5 patients (23.8%) had pulmonary metastasis. In patients with pulmonary metastasis, total thyroidectomy and bilateral radical lymph node resection was performed in 3 patients, lobectomy of the thyroid and radical lymph node resection in one patient, and partial thyroidectomy in one patient. All three patients who underwent total thyroidectomy are still alive. Internal irradiation by 131I and thyroid hormone replacement therapy was administered to 2 of 3 patients with pulmonary metastasis. CONCLUSION: Despite metastasis in the lymph nodes and even the lungs, the prognosis for patients with papillary carcinoma is good. Total thyroidectomy and positive 131I therapy are recommended for childhood and adolescent thyroid carcinoma with pulmonary metastasis.

Adenocarcinoma, Follicular↗

PubMed2006

Gastric mucin phenotype defines tumour progression and prognosis of intrahepatic cholangiocarcinoma: gastric foveolar type is associated with aggressive tumour behaviour.

AIMS: To identify the role of mucus core protein (MUC) in intrahepatic cholangiocarcinoma (ICC). METHODS AND RESULTS: We examined the expression profile of MUC2, MUC5AC and MUC6 by immunohistochemical staining in 100 ICCs and compared the clinicopathological factors and the immunohistochemical results. The expression frequency was: MUC2, 9%; MUC5AC, 40%; and MUC6, 21%. According to the gastric mucin expression profile, ICCs were classified into the following groups: null type (n = 43), gastric foveolar type (n = 36), pyloric gland type (n = 11) and gastric combined type (n = 10). Half of the gastric foveolar type and the gastric combined type were located in the hilar region, but the other types were predominant at the periphery (P = 0.0004). Well-differentiated components were more often detected in the gastric combined type and the pyloric gland type (P = 0.0281). The gastric foveolar type was associated with a higher incidence of lymph node metastasis (P < 0.0001). The pyloric gland type was associated with better survival and the gastric foveolar type was associated with worse survival. The gastric mucin phenotype was an independent prognostic factor by multivariate survival analysis. CONCLUSION: The gastric foveolar type of ICC was more often associated with aggressive tumour development, whereas the pyloric gland type exhibited less aggressive behaviour.

Adult↗

PubMed2005

'Scirrhous' type hepatocellular carcinomas: a special reference to expression of cytokeratin 7 and hepatocyte paraffin 1.

AIMS: 'Scirrhous' hepatocellular carcinoma (scirrhous HCC) is extremely rare and its characteristics remain unclear. We investigated the clinicopathological and immunohistochemical features of scirrhous HCC, compared with those of ordinary hepatocellular carcinoma (ordinary HCC). METHODS AND RESULTS: We compared the clinicopathological and immunohistochemical features of 20 resected cases of scirrhous HCC with those of 69 resected cases of ordinary HCC. Scirrhous HCC was characterized by its gross and histological findings, such as a higher proportion of contiguous multinodular type tumours, the absence of a complete fibrous capsule around the tumour, the absence of tumour necrosis and highly preserved portal tracts in the tumour. The immunohistochemical results revealed a significantly higher expression of cytokeratin 7 and a significantly lower expression of hepatocyte paraffin 1 in scirrhous HCC than in ordinary HCC (P<0.0001, respectively). There were no significant differences in proliferative activity and survival curves between the patients with scirrhous HCC and those with ordinary HCC. CONCLUSION: Scirrhous HCC has several particular gross, histological and immunohistochemical features. In particular, we would like to emphasize the greater immunohistochemical expression of cytokeratin 7 and lower expression of hepatocyte paraffin 1 in scirrhous HCC than in ordinary HCC.

Adenocarcinoma, Scirrhous↗

PubMed2003

Biochemical and ultrastructural analyses of IgLON cell adhesion molecules, Kilon and OBCAM in the rat brain.

Kilon (kindred of IgLON) and opioid-binding cell adhesion molecule belong to the IgLON subgroup of immunoglobulin superfamily together with the limbic system-associated membrane protein and neurotrimin. In the present study, we have analyzed biochemical and ultrastructural characterization of Kilon and opioid-binding cell adhesion molecule such as regional and developmental expression patterns, light and electron microscopic localization, and intermolecular interactions. Western blotting revealed a widespread distribution pattern of Kilon with high expression levels in the olfactory bulb, cerebral cortex, diencephalon, hippocampus, and cerebellum and low expression levels in the medulla oblongata and spinal cord. In contrast, opioid-binding cell adhesion molecule showed a regionally restricted expression pattern with high levels only in the cerebral cortex and hippocampus. Expression of Kilon and opioid-binding cell adhesion molecule was increased gradually during postnatal development and maintained until adulthood. Light microscopic immunohistochemistry demonstrated that the localization of opioid-binding cell adhesion molecule and Kilon coincided well with that of vesicle-associated membrane protein 2, a synaptic marker protein, in the cerebral cortex and hippocampus of adult brain. In the cerebellum, Kilon-immunoreactive puncta were observed to colocalize well with that of vesicle-associated membrane protein 2, while opioid-binding cell adhesion molecule immunoreactivity was observed only at part of synaptic glomeruli in the granular layer and rare in the molecular layer. Electron microscopic analysis revealed that Kilon and opioid-binding cell adhesion molecule immunoreactivity was observed mainly at postsynaptic sites of dendritic and somatic synapses in adult cerebral cortex and hippocampus. Only trace levels of Kilon and opioid-binding cell adhesion molecule were detected in the soluble fraction of a cortical homogenate, although a substantial amount of F3 was present in the soluble fraction. A binding analysis using a cross-linker and the immunoprecipitation technique demonstrated that Kilon and opioid-binding cell adhesion molecule interacted heterophilically and homophilically. These findings show that Kilon and opioid-binding cell adhesion molecule are clearly distinguishable from each other in regional expression and localization, and binding patterns. These differences possibly represent diverse functions of each IgLON molecule.

Animals↗

PubMed2003

Dendrite-associated opioid-binding cell adhesion molecule localizes at neurosecretory granules in the hypothalamic magnocellular neurons.

Opioid-binding cell adhesion molecule (OBCAM) is a member of the immunoglobulin superfamily containing limbic system-associated membrane protein (IgLON) subgroup of glycosylphosphatidylinositol-anchored immunoglobulin cell adhesion molecules. We have previously found that OBCAM is localized preferentially to dendrites compared with somata and terminals of hypothalamic vasopressin-secreting magnocellular neurons. This localization indicates that OBCAM is one of the dendrite-associated cell adhesion molecules. In the present study, we further characterized the localization and the sorting mechanism, and activity-dependent changes of this molecule in vasopressin-secreting magnocellular dendrites. Confocal microscopic observation revealed the preferential localization of OBCAM at the neurosecretory granules in the vasopressin-positive dendrites. Electron microscopic observation using chromogen-intensified and gold-conjugated methods also demonstrated the OBCAM labeling at most of the neurosecretory granules within the dendrites, while the labeling within the somata was observed at only a few neurosecretory granules. I.c.v. colchicine administration resulted in the disappearance of OBCAM immunoreactivity from the dendrites and in its concomitant accumulation at the somata, suggesting that OBCAM is synthesized at the somata and transported to the dendrites by dendrite-associated neurosecretory granules. During the postnatal development, OBCAM immunoreactivity targeted to vasopressin-positive dendrites became clear from at least 3 weeks after birth, although it appeared at only a few somata 2 weeks after birth. Phosphatidylinositol specific phospholipase C treatment of the membrane fraction of the supraoptic homogenate solubilized OBCAM. Kilon, another IgLON member, was also shown to localize at the neurosecretory granules of vasopressin-positive dendrites via the glycosylphosphatidylinositol anchor. High K(+)-stimulation appeared to cause the diffusion of OBCAM-labeled gold particles from neurosecretory granules together with the exocytosis. These findings indicate that OBCAM is synthesized within the somata, attached to vasopressin neurosecretory granules via the glycosylphosphatidylinositol anchor, and transported to the dendrites. Moreover, the subcellular localization of OBCAM is changed in an activity-dependent manner.

Animals↗

PubMed2003

Angiopoietin switching regulates angiogenesis and progression of human hepatocellular carcinoma.

AIM: Angiopoietin 1 (Ang-1) and its antagonist, angiopoietin 2 (Ang-2), are novel ligands that regulate the Tie2 receptor. The Ang-2 gene is upregulated in the hypervascular type of human hepatocellular carcinoma (HCC). To gain a better understanding of the role of the Ang-Tie2 system in HCC the expression of these genes was investigated in a series of human HCCs. METHODS: The expression of the angiopoietin and Tie2 proteins was investigated in nine normal liver tissues and 52 surgically resected HCCs. In addition, the effects of hypoxic stimuli on Ang-1, Ang-2, vascular endothelial growth factor (VEGF), and erythropoietin (EPO) expression was investigated in Hep3B cells. RESULTS: Ang-1, rather than Ang-2, was more frequently expressed in the normal liver. Ang-1 was expressed in 68% of HCCs, whereas Ang-2 was expressed in 81%, and was significantly higher in poorly differentiated HCCs characterised by high vascularity (p = 0.02), and in tumours with a peliotic change (p = 0.02). Strong expression of Tie2 was seen in tumour vessels in accordance with Ang-2 expression. In Hep3B cells, hypoxic stimuli upregulated VEGF and EPO, but not Ang-1 or Ang-2. CONCLUSIONS: These data support the evidence that the reversal of Ang-1 and Ang-2 expression plays an important role in the angiogenic and dedifferentiation processes in HCC. The hypoxic stimuli were not responsible for Ang-2 upregulation, unlike that of VEGF, in human HCC cells.

Aged↗

PubMed2003

[Surgical treatment for pulmonary metastases from colorectal cancer].

Blalock first reported pulmonary resection for metastatic colorectal cancer in 1944. Since then, surgical resection of pulmonary metastases has been generally accepted as a standard therapeutic procedure in properly selected cases. Recently, the criteria of eligibility have been progressively expanded according to the development of radiological diagnosis using helical computed tomography (CT), widespread of minimum invasive video-assisted thoracic surgery. In this review summarized the surgical treatment of pulmonary metastases from colorectal cancer based on the recent literatures. Major areas of controversy remain with respect to the following aspects: prognostic factors (i.e., number of metastases, size of tumor, disease free interval, preoperative serum carcinoembryonic antigen level), procedure of operation (i.e., role of video-assisted thoracic surgery, lymphonode dissection), indication of surgical treatment on metastases both lung and liver, role of repeat thoracotomy for recurrence. For all above-mentioned points it appeared reasonable to try to the cooperative multicentric clinical prospective study.

Colorectal Neoplasms↗

PubMed2002

Toxicity assessment of 255 chemicals to pure cultured nitrifying bacteria using biosensor.

The bioassay has been attracting attention as a method of toxicity assessments of micropollutants in the environment. In this study, we report the characteristics (selectivity and sensitivity) of the nitrifying bacteria biosensor for 255 kinds of chemicals as a model of chemical contaminant in the environment and the results of evaluation of mixed samples of several substances. In the nitrifying bacteria respiration inhibition test using the biosensor, 56 chemicals were detected. It was found that this biosensor is especially sensitive to seven chemicals that have a thiocarbonyl functional group (>C=S), such as a thioamide group of thiocarbamate group. These chemicals are considered to specifically inhibit AMO by chelation of copper. The samples consisted of a mixture of seven types of anilines that inhibit respiration in the bacteria, a mixture of five types of chlorophenols, and a mixture of eight types of substances that contain thiocarbonyl groups were examined. All of the mixed samples inhibited the respiration of the nitrifying bacteria more than 10% by the inhibition rate, and observed a synergistic effects of the substances in the samples.

Aniline Compounds↗

PubMed2001

Disparate effects of interleukin 11 and thrombopoietin on megakaryocytopoiesis in vitro.

The effects of interleukin-11 (IL-11) and thrombopoietin (TPO) on murine megakaryocytopoiesis were studied using a serum-free culture system. Acting alone, both IL-11 and TPO increased the number of acetylcholinesterase (AchE)(+)cells (megakaryocytes), the latter being more potent than the former. TPO, but not IL-11, increased the mean AchE activity per megakaryocyte (AchE activity/megakaryocyte). TPO increased both the number of megakaryocytes with high ploidy, and of those with low ploidy. In contrast, IL-11 increased only the number of megakaryocytes with high ploidy. The effect of TPO on megakaryocyte ploidy was stronger than that of IL-11. Both IL-11 and TPO increased the proportion of large megakaryocytes, but the latter was more potent than the former. While the stimulatory effects of IL-11 and TPO on the number of megakaryocytes were enhanced by IL-3 or stem cell factor (SCF), synergism of IL-11 or TPO with IL-3 or SCF in stimulating AchE activity/megakaryocyte was inconsistent. IL-11 and TPO stimulated the formation of colony-forming units of megakaryocyte in the presence of IL-3, but not alone, with similar maximum colony numbers for both cytokines. Our findings thus demonstrate that IL-11 principally stimulates megakaryocyte maturation rather than the proliferation of megakaryocytes, whereas TPO stimulates both.

Acetylcholinesterase↗

PubMed2001

Stereoselective effect of (R)- and (S)-1-methyl-1,2,3,4-tetrahydroisoquinolines on a mouse model of Parkinson's disease.

We carried out behavioral, pathological, and biochemical studies in order to determine whether the stereo-structure of 1-methyl-1,2,3,4-tetrahydroisoquinoline (1-MeTIQ) affects the onset of Parkinson's disease-like symptoms, which are induced by 1,2,3,4-tetrahydroisoquinoline (TIQ) in mice. Pretreatment with (R)-1-MeTIQ or its racemate (RS)-1-MeTIQ prevented the TIQ-induced bradykinesia. Pretreatment with a combination of L-DOPA and carbidopa significantly prevented subsequent TIQ-induced bradykinesia. Furthermore, the pathological study demonstrated that either (R)-1-MeTIQ or its racemate protected against TIQ-induced loss of tyrosine hydroxylase-positive cells of the substantia nigra pars compacta. (R)-1-MeTIQ and its racemate also prevented the TIQ-induced reduction in the levels of dopamine and its metabolites in the striatum. Serotonin and its metabolite were not affected by repeated administration of (RS)-1-MeTIQ or its derivatives. On the other hand, (S)-1-MeTIQ induced moderate but significant bradykinesia, whereas (R)-1-MeTIQ did not induce this behavioral abnormality at all. In addition, (S)-enantiomer prevented the onset of TIQ-induced bradykinesia, though to a lesser extent than did either (R)-enantiomer or its racemate. However, (S)-enantiomer did not prevent the loss of tyrosine hydroxylase-positive neurons in the substantia nigra pars compacta. We concluded that (R)-1-MeTIQ, and not (S)-enantiomer, plays a crucial role in protection against TIQ-induced parkinsonism, a fact which suggests that enantiomeric biochemical events such as 1-MeTIQ biosynthesis may participate in the pathogenesis of Parkinson's disease.

3,4-Dihydroxyphenylacetic Acid↗

PubMed2001

Expression of a tumor-associated antigen RCAS1 in hepatocellular carcinoma.

RCAS1 has been reported as a tumor-associated antigen in uterine and ovarian carcinomas. In vitro studies on RCAS1 indicated that it might function as an apoptosis-inducing factor since binding between RCAS1 and its receptor induced apoptosis in receptor-expressing cells. In this study, 68 surgically resected samples of hepatocellular carcinoma (HCC) were prepared and RCAS1 expression was examined immunohistochemically, because RCAS1 was also positive in all HCC cell lines tested. Clinical and pathological parameters were then compared between RCAS1-positive and -negative HCC cases. As a result, RCAS1 is expressed in 26.5% of HCC cases and vascular invasion is observed at a much higher rate in the RCAS1-positive cases (72.2%) than in RCAS1-negative cases (24.0%). RCAS1 is not an antigen specific for gynecological cancers. In HCC cases, the RCAS1-positive percentage is not high, however, RCAS1-positive HCCs exhibited a trend towards invasive character.

Animals↗

PubMed2001

Biochemical and pathological study of endogenous 1-benzyl-1,2,3,4-tetrahydroisoquinoline-induced parkinsonism in the mouse.

We administered 1-benzyl-1,2,3,4-tetrahydroisoquinoline (1-BnTIQ; 80 mg/kg, i.p.), an endogenous neurotoxin known to cause bradykinesia, the Parkinson's disease-like symptom, in order to obtain biochemical and pathological evidence of behavioral abnormalities. Immunohistochemical analysis demonstrated that 1-BnTIQ did not decrease the number of tyrosine hydroxylase-positive cells in the substantia nigra. Biochemical analysis demonstrated significantly increased striatal dopamine (DA) content, while DA metabolites in the striatum remained at control levels. We concluded that the 1-BnTIQ-induced bradykinesia has a different mechanism of action than that underlying the MPTP-induced depletion of striatal DA neurons.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed2001

beta-Phenylethylamine modulates acetylcholine release in the rat striatum: involvement of a dopamine D(2) receptor mechanism.

We examined the effects of beta-phenylethylamine on striatal acetylcholine release in freely moving rats using in vivo microdialysis. beta-Phenylethylamine at 12.5 mg/kg, i.p. did not affect acetylcholine release in the striatum, whereas 25 and 50 mg/kg, i.p. immediately induced an increase in acetylcholine release in the striatum at 15-45 min. This increase following intraperitoneal administration of beta-phenylethylamine (25 mg/kg) was not affected by locally applied SCH-23390 (R(+)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine, 10 microM), a dopamine D(1) receptor antagonist, nor by raclopride (10 microM), a dopamine D(2) receptor antagonist. The increased release of acetylcholine induced by beta-phenylethylamine was suppressed by local infusion of tetrodotoxin (1 microM). In contrast, the extracellular acetylcholine level in the striatum was significantly decreased by local application of beta-phenylethylamine (10 and 100 microM) in the striatum via a microdialysis probe. The decrease was completely blocked by local co-application of raclopride (10 microM). The beta-phenylethylamine-induced decrease in striatal acetylcholine release was not affected by co-perfusion with SCH-23390 (10 microM). These results indicate that systemic administration of beta-phenylethylamine increases acetylcholine release, whereas locally applied beta-phenylethylamine decreases striatal acetylcholine release in freely moving rats. Furthermore, the dopaminergic system, through the dopamine D(2) receptor, is involved in the locally applied beta-phenylethylamine-induced decrease in acetylcholine in the striatum.

Acetylcholine↗

PubMed2001

Kinetic analysis of megakaryopoiesis induced by recombinant human interleukin 11 in myelosuppressed mice.

Recombinant human interleukin 11 (rhIL-11) has previously been shown to ameliorate thrombocytopenia in several animal models. To elucidate the mechanisms involved in rhIL-11-induced hematopoiesis, a kinetic analysis of megakaryopoiesis was performed in mitomycin C (MMC)-induced myelosuppressive mice. Mice intravenously injected with MMC (2 mg/kg) for two consecutive days from day -1 developed severe thrombocytopenia with a nadir of platelet counts at 24x10(4)/microl on day 12 and neutropenia. Treatment with rhIL-11 (500 microg/kg/day) from day 1 to 21 significantly ameliorated the degree and duration of thrombocytopenia and enhanced the platelet recovery, and also enhanced the recovery from neutropenia. In MMC-treated mice, the decreases in bone marrow megakaryocyte progenitors and megakaryocyte counts preceded the decrease in platelet counts by MMC treatment. RhIL-11 induced an increase in the number of megakaryocyte progenitors from day 4 to 14, followed by an increase in the megakaryocytes by day 20. There was a ploidy shift in megakaryocytes towards lower ploidy cells by day 9 in myelosuppressed mice. RhIL-11 caused a shift towards a higher ploidy with 32 and 64N on day 4, and 32N on day 14. These results suggest that rhIL-11 ameliorates the thrombocytopenia via the stimulation of both the maturation and commitment followed by the proliferation of megakaryocytic cells.

Alkylating Agents↗

PubMed2001

Immunohistochemical phenotypic alterations of rabbit autologous vein grafts implanted under arterial circulation with or without poor distal runoff-implications of vein graft remodeling.

Although intimal hyperplasia is a major cause limiting the long-term patency of the vein grafts, its precise mechanisms, including the effect of poor runoff, has not yet been well characterized. We thus designed the present study to try to determine the effect of poor runoff arterial flow to the phenotypic alterations of the graft wall by immnohistochemistry using anti-intermediate filaments (alpha-SM actin, desmin, and vimentin) and anti-myosin heavy chain (SM1, SM2, and SMemb) specific antibodies. Vein grafts implanted under the poor runoff hind limb of rabbits showed enhanced intimal hyperplasia, however, no apparent difference in the cytoskeleton expression, including intermediate filaments and MHC, between two groups until 4 weeks. Interestingly, six of eight vein grafts at 2 weeks after implantation in both groups showed the accumulations of perivascular fibroblast-like phenotype (negative for SM1, alpha-SM actin, and desmin) in some parts of the outer neointima, whereas the inner neointima at 2 weeks and the whole neointima at 4 weeks were mainly occupied by a smooth muscle phenotype (positive for these three). Although the cellular origin of these cells is still unknown, these results suggest that the migration of non-muscle mesenchymal cells is involved in the neointima and thus may provide a clue for better understanding vein graft remodeling.

Anastomosis, Surgical↗