Requirement for tyrosine kinase-ERK1/2 signaling in alpha 1 beta 1 integrin-mediated collagen matrix remodeling by rat mesangial cells

Abnormal mesangial extracellular matrix remodeling by mesangial cells (MCs) is the hallmark of progressive glomerulonephritis (GN). We recently showed, using a type I collagen gel contraction assay, that alpha 1 beta 1 integrin-dependent MC adhesion and migration are necessary cell behaviors for collagen matrix remodeling. To further determine the mechanism of alpha 1 beta 1 integrin-mediated collagen remodeling, we studied the signaling pathways of MCs that participate in the regulation of collagen gel contraction. Immunoprecipitation and phosphotyrosine detection revealed that gel contraction is associated with the enhanced activity and phosphorylation of ERK1/2 by MCs. The tyrosine kinase inhibitors herbimycin and genistein inhibited collagen gel contraction dose dependently. Furthermore, targeting ERK1/2 activity with a MEK inhibitor, PD98059, and antisense ERK1/2 hindered gel contraction in a dose-dependent manner. Similar inhibitory effects on gel contraction and ERK1/2 phosphorylation were observed when MC-mediated gel contraction was performed in the presence of function-blocking anti-alpha1 or anti-beta1 integrin antibodies. However, cell adhesion and migration assays indicated that PD98059 and antisense ERK1/2 blocked alpha 1 beta 1 integrin-dependent MC migration, but did not interfere with collagen adhesion, although there was a marked decrease in ERK1/2 phosphorylation and ERK1/2 protein expression in cell adhesion on type I collagen. None of the above could affect membrane expression of alpha 1 beta 1 integrin. These results suggested that ERK1/2 activation is critical for the alpha 1 beta 1 integrin-dependent MC migration necessary for collagen matrix reorganization. We therefore conclude that ERK1/2 may serve as a possible target for pharmacological inhibition of pathological collagen matrix formation in GN.

A novel bioactive 31-amino acid endothelin-1 is a potent chemotactic peptide for human neutrophils and monocytes

Endothelin (ET)-1(1-31) is a novel 31-amino acid-length peptide derived from big ET-1 by chymase or other chymotrypsin-type proteases and is a major ET derivative in human neutrophils. In this study, we revealed that ET-1(1-31), but not big ET, exhibited chemotactic activities toward human neutrophils and monocytes as an inflammatory mediator, although the effects were less potent than those of formyl-methionyl-leucyl-phenylalanine or interleukin-8. However, the chemotactic effects of ET-1(1-31) were much greater than those of the 21-amino acid ET-1, ET-1(1-21). Checkerboard analyses revealed that the effects are chemotactic rather than chemokinetic. The effects of ET-1(1-31) are not mediated by interleukin-8 or monocyte chemoattractant protein-1. The chemotactic effects and an increase in intracellular-free Ca(2)(+) caused by ET-1(1-31) were significantly inhibited by BQ123, an ET(A) receptor antagonist, but not by BQ788, an ET(B) receptor antagonist, suggesting that ET-1(1-31) mediates chemotaxis through an ET(A) or ET(A)-like receptor.

Prognostic significance of BRCA1 expression in Japanese sporadic breast carcinomas

BACKGROUND

BRCA1 is a tumor suppressor gene that is responsible for hereditary breast and ovarian carcinoma syndrome. The primary objective of the current study was to investigate the influence of BRCA1 expression on the prognoses of sporadic breast carcinomas.

METHODS

A cohort of 175 Japanese women with invasive breast carcinoma who had no family history in first-degree relatives was studied. Expression of BRCA1 was determined by an immunohistochemical procedure in which the MS110 monoclonal antibody was used. Kaplan--Meier and Cox proportional regression survival analyses were used to compare negative and positive BRCA1 patients.

RESULTS

One hundred fifteen (65.7%) of the 175 specimens showed positive BRCA1 staining (> 10% cells were immunoreactive). During a median follow-up of 4.4 years, negative BRCA1 patients had worse disease free survival than positive BRCA1 patients (35 % vs. 7%, respectively; P < 0.0001). BRCA1 expression was significantly inversely correlated with histologic grade (P < 0.0001) but not with lymph node status or other conventional prognostic markers. In multivariate analysis using the Cox regression model, positive BRCA1 emerged as an independent prognostic indicator for disease free survival.

CONCLUSIONS

The results of this study suggest that BRCA1 may be a valuable marker for identifying women with sporadic breast carcinoma at high risk of developing recurrence, and who may be candidates for trials investigating new therapies in combination with standard adjuvant therapy.

Adenocarcinoma arising in gastric heterotopic pancreas: clinicopathological and immunohistochemical study with genetic analysis of a case

Heterotopic pancreas in the stomach is a relatively common congenital condition, but the risk of malignant transformation is extremely low. In this study, we describe a case of adenocarcinoma arising from a gastric heterotopic pancreas and we consider its morphological and immunohistochemical features and genetic analysis, in order to examine its histogenesis. This unusual sequela was seen in a 57-year-old woman. Image studies showed a protruding lesion with a central ulcer located in the lesser curvature from the angle to the body of the stomach. A biopsy specimen confirmed this lesion as adenocarcinoma before total gastrectomy. The tumor showed mixed patterns of solid neoplastic-cell proliferation and moderately differentiated glandular structures, and also showed transitional lesions to obvious malignancy, that is, dysplasia, or adenocarcinoma in situ. Neoplastic cells had positive immunoreactivity for carbohydrate antigen (CA) 19-9, mucin (MUC) 1, and insulin, and the mutant allele-specific amplification method revealed a point mutation at K-ras codon 12 (GGT [Gly]-->GAT [Asp]), which is the most common mutational change observed in patients with pancreatic carcinoma. The features of the present case provide clear evidence that this tumor originated from heterotopic pancreatic tissue rather than from gastric epithelium.

Relationship between functional deficit and severity of experimental fast-strain injury of rat skeletal muscle

We developed a rat model of fast-strain muscle injury to examine the relationship between functional deficit and the degree of muscle damage. A single fast strain was applied to the right plantaris (Plt) muscle of adult male rats. A tetanic contraction was induced by stimulating the sciatic nerve. Three types of strain injuries were produced by manipulating the timing of strain and contraction conditions, including applying the strain at: (1) the shortening phase (SP), (2) the full contraction phase (FCP) during tetanic contraction and (3) when the muscle is not contracting, i.e. non-contraction (NC). The contralateral Plt muscle was used as the control. Morphological and functional analysis were performed and the severity of strain injury was estimated by measuring [3H]thymidine labelling 48 h after the strain was applied. The results show a significant decrease in tension output in all three groups at 5 min after strain application (P < 0.01). The functional deficit lasted for 3 weeks in the NC group, while rats of the SP and FCP groups showed recovery 1 week after strain. Increased uptake of [3H]thymidine was similar in SP and FCP groups, but 3.5-fold higher in NC than in SP and FCP groups (P < 0.01). Histological analysis revealed an increase in the size of interstitial spaces of the muscle in NC compared to SP and FCP groups (P<0.05). Our results suggest that the contraction of muscle fibres limits the severity of connective tissue damage, and that muscle damage accompanied by disruption of the muscle connective tissue network requires a relatively longer recovery time.

Anabolic steroids increase exercise tolerance

The influence of an anabolic androgenic steroid (AAS) on thymidine and amino acid uptake in rat hindlimb skeletal muscles during 14 days after a single exhaustive bout of weight lifting was determined. Adult male rats were divided randomly into Control or Steroid groups. Nandrolone decanoate was administered to the Steroid group 1 wk before the exercise bout. [3H]thymidine and [14C]leucine labeling were used to determine the serial changes in cellular mitotic activity, amino acid uptake, and myosin synthesis. Serum creatine kinase (CK) activity, used as a measure of muscle damage, increased 30 and 60 min after exercise in both groups. The total amount of weight lifted was higher, whereas CK levels were lower in Steroid than in Control rats. [3H]thymidine uptake peaked 2 days after exercise in both groups and was 90% higher in Control than in Steroid rats, reflecting a higher level of muscle damage. [14C]leucine uptake was approximately 80% higher at rest and recovered 33% faster postexercise in Steroid than in Control rats. In a separate group of rats, the in situ isometric mechanical properties of the plantaris muscle were determined. The only significant difference was a higher fatigue resistance in the Steroid compared with the Control group. Combined, these results indicate that AAS treatment 1) ameliorates CK efflux and the uptake of [3H]thymidine and enhances the rate of protein synthesis during recovery after a bout of weight lifting, all being consistent with there being less muscle damage, and 2) enhances in vivo work capacity and the in situ fatigue resistance of a primary plantarflexor muscle.

Thymidine phosphorylase expression correlates with tumor differentiation and Bcl-2 in invasive breast cancer

BACKGROUND

Angiogenesis plays an important role in the growth and metastasis of solid tumors. Several angiogenic factors have been identified, and thymidine phosphorylase (TP) is thought to be one such factor. To date, little information is available on the relationship between TP and other clinicopathological variables.

METHODS

Formalin-fixed, paraffin-embedded materials from 116 primary breast carcinomas were used. The expression of TP, estrogen receptor, Bcl-2, Bax, p53, c-erbB-2 and MIB-1 was examined by immunohistochemical methods.

RESULTS

Nuclear and/or cytoplasmic TP expression was observed in the neoplastic cells, and accentuation of TP was often present at the infiltrating tumor edge and intraductal spread region. Tumor cell TP expression was significantly inversely correlated with histological grade (p< 0.05) and positively correlated with Bcl-2 expression, but no association with other tumor variables was found.

CONCLUSIONS

TP is associated with Bcl-2 expression and tumor differentiation in breast cancer. TP may be a new prognostic parameter for breast cancer.

Cholesterol-lowering effect of NK-104, a 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, in guinea pig model of hyperlipidemia

Although benefits of statins have been demonstrated even in normolipidemic patients at high risk, the main target of statin therapy is the hypercholesterolemic patient. The aim of this study was to examine the hypocholesterolemic effect of NK-104 ((+)-monocalcium bis((3R,5S,6S)-7-[2-cyclopropyl-4-(4-fluorophenyl)-3-quinolyl]- 3,5-dihydroxy-6-heptenoate), CAS 147526-32-7), a potent 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor, and its mechanism of action in hypercholesterolemic animals. In guinea pigs fed a diet containing 15% (w/w) fat rich in laurate for 6 weeks, the liver cholesterol content was markedly increased and plasma total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) and LDL-apoB were elevated 4.8, 5.2 and 1.7 times, respectively, compared with normal diet fed animals. These changes were maintained by reduced LDL clearance in the presence of markedly cholesterol-enriched LDL in the plasma. In this model, the LDL-C reduction rates by 0.1, 0.3 and 1 mg/kg of NK-104 orally administered for 2 weeks (from week 4 to week 6), were 11, 27 and 32%, respectively, from controls, being similar in normal guinea pigs previously examined. Those for 3 and 10 mg/kg of atorvastatin (CAS 134523-00-5) were 25 and 39%, respectively. Thus about 10 times higher doses of atorvastatin were required than of NK-104 to cause a similar cholesterol-lowering effect. This reduction of plasma cholesterol was accompanied by an improvement of LDL clearance (24 and 47% increase in fractional catabolic rate by 1 mg/kg of NK-104 and 10 mg/kg of atorvastatin, respectively) and LDL composition. In conclusion, in guinea pig hypercholesterolemia caused by high-laurate diet, NK-104 and atorvastatin lowered plasma cholesterol levels with an improvement of LDL composition and with an increase in LDL clearance, presumably through reduction of the liver cholesterol content, although hepatic cholesterol synthesis might have been markedly suppressed in this model.

Electron paramagnetic resonance study on free radical scavenging and/or generating activity of dopamine-4-O-sulfate

The free radical scavenging and/or generating activity of dopamine-4-O-sulfate was examined and compared with that of dopamine. In humans, dopamine mostly exists in two isomeric forms of sulfate ester conjugates as metabolites; i.e., dopamine-3-O-sulfate and dopamine-4-O-sulfate in the circulation. Dopamine is generally believed to be oxidized by molecular oxygen or another reactive oxygen species under physiological conditions, to form oxidized dopamine derivatives that are cytotoxic. However, it is not known whether dopamine conjugates are generated on interaction with reactive oxygen species or not. In the present study, we measured the susceptibility to oxidization of dopamine-4-O-sulfate by using electron paramagnetic resonance (EPR) spectroscopy and optical absorption spectrometry. Dopamine was easily oxidized and dopamine-derived radicals appeared, whereas dopamine-4-O-sulfate was not oxidized under physiological conditions. Furthermore, dopamine-4-O-sulfate did not react with a strong oxidizing agent, sodium periodate. These results suggest that dopamine-4-O-sulfate has resistance against autoxidation, and seems to be a stable metabolite of dopamine.

Antioxidants inhibit JNK and p38 MAPK activation but not ERK 1/2 activation by angiotensin II in rat aortic smooth muscle cells

Angiotensin II (Ang II) induces vascular smooth muscle cell (VSMC) hypertrophy, which results in several cardiovascular diseases. Ang II-induced cellular events have been mediated, in part, by reactive oxygen species (ROS) which also involve activation of mitogen-activated protein (MAP) kinases. Although it has been proposed that the therapeutic administration of antioxidants is useful for vascular diseases, the precise mechanisms which regulate ROS-sensitive signaling events have not been well characterized. Thus, we hypothesized that antioxidants may affect ROS-mediated MAP kinases activation induced by Ang II. The present findings showed that Ang II stimulated rapid and significant activation of ERK 1/2, JNK and p38 MAPK in cultured rat aortic smooth muscle cells (RASMC). Ang II-induced ERK 1/2 activation was not affected by all antioxidants examined, whereas JNK was sensitive to all antioxidants. In contrast, p38 MAPK activation was inhibited by DPI and ascorbic acid concentration-dependently, but by NAC only at high concentration. DETC and Trolox C had no effects on p38 MAPK activation by Ang II. We further examined the effects of antioxidants on Ang II-induced increases in oxygen consumption as an index of ROS generation in RASMC. DPI strongly inhibited Ang II-induced increases in oxygen consumption. DETC also inhibited Ang II-induced oxygen consumption, whereas ascorbic acid markedly augmented it. These findings suggest that the inhibitory effects of antioxidants on MAP kinases activation in VSMC are attributable, in part, to their modulating effects on ROS generation by Ang II in VSMC. Thus, inhibition of MAP kinases by antioxidants may imply their usefulness for relief of cardiovascular diseases.

Roles of thromboxane A2 and leukotriene B4 in radicular pain induced by herniated nucleus pulposus

Biologically active substances, such as prostaglandins, thromboxanes, and leukotrienes, which are metabolites involved in the arachidonic acid cascade, are detected in herniated disc samples obtained from patients with lumbar disc herniation. However, little is known concerning the relationships between these substances and clinical symptoms such as radicular pain. Thromboxane A2 (TXA2) induces not only potent platelet aggregation, but also blood vessel contraction. Leukotriene B4 (LTB4), a potent chemotactic agent, plays a role in inflammatory reactions by recruiting neutrophils and lymphocytes. The purpose of this study was to examine the roles of TXA2 and LTB4 in the hyperalgesia induced by application of nucleus pulposus to the lumbar nerve root in the rat. TXA2 synthetase inhibitor and LTB4 receptor antagonist, which were injected into the epidural space, decreased mechanical hyperalgesia at both three and seven days after epidural injection. There were no significant differences in sensitivity to noxious thermal stimuli following application of the nucleus pulposus or an epidural injection. Epidural injection of LTB4 receptor antagonist and/or TXA2 synthetase inhibitor may attenuate the painful radiculopathy due to lumbar disc herniation. In conclusion, our findings suggest that TXA2 and LTB4 may play significant roles in mechanical hyperalgesia induced by autologous nucleus pulposus.

Hypermethylation does not account for the frequent loss of the retinoic acid receptor beta2 in breast carcinoma

Hypermethylation of the retinoic acid receptor (RAR) beta2 has been detected in breast cancer cell lines and is known to repress the level of RAR beta2 transcription. RAR beta2 mRNA loss has often been detected in breast cancer tumors, whether promoter region methylation of the RAR beta2 gene accounts for its loss is still unknown. We examined the methylation status of RAR beta2 in breast tumors; 21 out of 50 (42%) breast tumors showed RAR beta2 hypermethylation. RT-PCR analysis showed a complete loss of RAR beta2 mRNA expression in 15 out of 43 (35%) breast tumors. No correlation between the hypermethylation and RAR beta2 loss was found, suggesting that hypermethylation is not fully responsible for the loss of expression of the RAR beta2 gene during breast tumorigenesis.

Novel polymorphisms of prostate-specific antigen (PSA) gene associated with PSA mRNA expression in breast cancer

A growing body of evidence suggests that prostate-specific antigen (PSA) is a novel prognostic factor for breast cancer. The molecular mechanism of variant PSA expression in breast cancer has remained poorly understood in spite of intensive research. Previous studies have shown that the coding region of the PSA gene is not a target for mutations in prostate cancer and breast cancer. The purpose of this study was to analyze genetic variations in the promoter region of the PSA gene, and to detect whether such variations are correlated with PSA mRNA expression in breast tumors. We identified two polymorphisms in the proximal promoter region of the PSA gene. These polymorphisms are located at positions -252 (G or A) and -205 (A or AA), and generate three genotypes. The genotypes were associated with PSA mRNA expression. Our findings suggest that these polymorphisms identified in the proximal promoter region may affect the transcriptional activity of PSA.

Evaluation of carriers of bone morphogenetic protein for spinal fusion

STUDY DESIGN

Posterolateral lumbar transverse process fusion in a rabbit model was performed using two different carriers for recombinant human morphogenetic protein-2, one having a porous structure and the other being a Type I collagen sheet.

OBJECTIVES

To compare the effectiveness of two different carriers for recombinant human morphogenetic protein-2 in achieving lumbar intertransverse process arthrodesis.

SUMMARY OF BACKGROUND DATA

The application of osteoinductive growth factors at various anatomic sites, such as in long bones and spinal segments, has been performed experimentally by many researchers. Although many carriers of osteoinductive factors have been reported, the most effective carrier has not been established. We have reported the efficacy of sintered bovine bone, True Bone Ceramics, which is coated with Type I collagen as a carrier of recombinant human bone morphogenetic protein-2 in achieving lumbar intertransverse process arthrodesis. True Bone Ceramics is a crystallized form of bone minerals made from sintering bovine bone at high temperatures and possesses natural trabecular structure. The crystalline character of True Bone Ceramics is similar to that of artificial hydroxyapatite. In this study we focused on the structure of two different carriers to facilitate osteosynthesis in lumbar arthrodesis.

METHODS

Fifty-four adult rabbits underwent bilateral lumbar intertransverse process arthrodesis at L4-L5. The animals were divided into five groups and had implants placed as follows: Group 1, autograft group, harvested autologous corticocancellous bone from the posterior iliac crest; Group 2, TBC group, True Bone Ceramics alone; Group 3, TBC-TBMP group, True Bone Ceramics coated with Type I collagen infiltrated with 100 microg of recombinant human bone morphogenetic protein-2; Group 4, collagen group, Type I collagen sheet; and Group 5, collagen-BMP group, implanted collagen sheet containing 100 microg of recombinant human bone morphogenetic protein-2. Spinal fusion was evaluated by radiographic analysis, manual palpation, biomechanical testing, and histologic examination at both 3 and 6 weeks after surgery.

RESULTS

Radiographs in the TBC-TBMP group showed a continuous trabecular pattern within the intertransverse area at 3 weeks after surgery. The fusion mass in the intertransverse area was more prominent than in the other groups. At 3 weeks after surgery the TBC-TBMP group had higher fusion rates based on manual palpation, and the fusions showed significantly higher tensile strength and stiffness. The histologic findings in the TBC-TBMP group at 3 weeks after surgery showed a cortical bone rim around the edge of the fusion mass, and contiguous new bone appearing between the recipient bone and the matrix of TBC without evidence of foreign body formation. In the collagen-BMP group, less mature bone formation was present within the grafted area and the new bone was not contiguous, even at 6 weeks after surgery.

CONCLUSIONS

As a carrier for recombinant human bone morphogenetic protein-2, True Bone Ceramics, possessing a bony or porous structure, was more effective than a Type I collagen sheet in achieving a faster and stronger lumbar spinal fusion in a rabbit model.

Long-term regulation of catecholamine formation by ouabain in cultured bovine adrenal chromaffin cells

The long-term effects of ouabain, an inhibitor of Na+/K+ -ATPase, on catecholamine formation in cultured bovine adrenal chromaffin cells were examined. The increase in [14C]catecholamine formation from [14C]tyrosine induced by ouabain was dependent on incubation time, and its maximal effect was observed after incubation for 8 h. The stimulatory effect of ouabain was concentration dependent (10-300 nM), causing maximal stimulation at 300 nM. The formation of [14C]catecholamines induced by ouabain was not increased by incubation with [14C]DOPA instead of [14C]tyrosine. Ouabain-induced [14C]catecholamine formation was influenced by decreases in extracellular Ca2+ concentration, but not by the presence of cycloheximide or actinomycin D. These results suggested that ouabain stimulates continuous activation of hydroxylation of tyrosine through a Ca2+ -dependent mechanism in cultured bovine adrenal chromaffin cells.

Determination of the levels of novel 31-amino acid endothelins and endothelins in human lungs

An effective method for determination of the levels of newly discovered 31-amino acid endothelins [ETs(1-31)] as well as big ETs and 21-amino acid ETs [ETs(1-21)], in human lungs has been developed. About 85% of ETs in human lung homogenates were recovered on acid extraction 8 times. Most of the published protocols for the determination of tissue ETs involve a reverse-phase minicolumn to separate proteins from peptides, after which the levels of ETs are directly determined by enzyme immunoassay. The levels determined, however, include fairly high amounts of non-bioactive ET metabolites in tissues and the data reported are diverse. We established an effective methods for the extraction and the separation of nine different muscle constricting ETs from their metabolites on a reverse-phase C18 column. Using this protocol, the levels of ETs in human lungs were determined by means of a sandwich-enzyme immunoassay specific for each ET derivative. The levels of ET-2(1-21) were the highest among those of ETs, and the levels of ETs(1-31) were in a similar range to those of big ETs but were lower than those of ETs(1-21). This method can be utilized to assess the pathophysiological roles of ETs(1-31) in various human organs.

Alteration in synaptic inputs through C-afferent fibers to substantia gelatinosa neurons of the rat spinal dorsal horn during postnatal development

The change in synaptic inputs through primary afferent C- and A-fibers during postnatal development was examined in substantia gelatinosa neurons of a rat spinal cord slice with an attached L5 dorsal root by use of the blind whole-cell patch-clamp technique; the synaptic responses were compared between the slices obtained from immature (postnatal days 21-23) and mature (postnatal days 56-60) male rats. The mono- and/or polysynaptic afferent inputs were monitored by recording glutamatergic excitatory postsynaptic currents and potentials evoked by stimulating C- and A-fibers, the identification of which was based on the values of threshold stimulus intensity and of the conduction velocity of the fibers, determined by intracellular recordings from dorsal root ganglion neurons. Immature substantia gelatinosa neurons received synaptic inputs through Abeta-, Adelta- and C-afferents, with proportions of 51%, 46% and 36%, respectively. In mature substantia gelatinosa neurons, C- and Adelta-afferent inputs were increased in number (to 84% and 86%, respectively), while Abeta-inputs were decreased to 9%. In both immature and mature rats, repetitive stimulation of C-afferents did not elicit any slow responses, which are longer in duration than the monosynaptic excitatory postsynaptic currents, although C-fibers are known to contain not only excitatory amino acids, but also neuropeptides such as substance P, which is thought to be involved in the production of slow responses. These results indicate that both C- and Adelta-afferents innervating substantia gelatinosa neurons are reorganized following maturation, accompanied by a withdrawal or elimination of Abeta-fibers from the substantia gelatinosa, probably due to a competition among the fibers during development. In spite of the developmental increase in C-fiber inputs, mature as well as immature substantia gelatinosa neurons did not display any slow synaptic responses, which appear to be mediated by transmitters other than excitatory amino acids.

Early complications of high-dose methylprednisolone sodium succinate treatment in the follow-up of acute cervical spinal cord injury

STUDY DESIGN

A prospective, randomized, and double-blind study comparing high-dose methylprednisolone sodium succinate (MPSS) with placebo, in the treatment of patients with acute cervical spinal cord injury.

OBJECTIVES

To evaluate the complications of high-dose MPSS in patients with acute cervical spinal cord injury when administered within 8 hours of injury.

SUMMARY OF BACKGROUND DATA

High-dose therapy with MPSS has been demonstrated to improve the recovery of motor function in patients with acute cervical spinal cord injury. However, little is known about the follow-up complications.

METHODS

Forty-six patients, 42 men and 4 women (mean age, 60.6 years; range, 18-84), were included in the study: 23 in the MPSS group and 23 in the placebo group. They were treated without surgery for spinal cord injury in the cervical spine, and were enrolled in the trial if a diagnosis had been made and treatment had begun within 8 hours. Complications of high-dose therapy with MPSS were compared with placebo treatment throughout the study period and up to 2 months after injury.

RESULTS

The MPSS group had 13 patients (56.5%) with complications, whereas the placebo group had 8 (34.8%). The difference between the two groups was not statistically significant (P = 0.139). There were eight instances of pulmonary complication with MPSS (34.8%) and one instance (4.34%) with placebo (P = 0.009). There were four instances of gastrointestinal complication (17.4%) with MPSS and none with placebo (P = 0.036). Pulmonary (complications were more prevalent in patients aged more than 60 years (P = 0.029).

CONCLUSION

Aged patients with cervical spinal injury may be more likely to have pulmonary side effects (P = 0.029) after high-dose therapy with MPSS and thus deserve special care.

Hand-assisted laparoscopic splenectomy for idiopathic thrombocytopenic purpura during pregnancy

A successful case of a hand-assisted laparoscopic splenectomy with low-pressure pneumoperitoneum for autoimmune thrombocytopenic purpura in a patient at 23 weeks' gestation is reported. Preoperative splenic arterial embolization was performed on the same day as the operation using painless contour embolic material and super-absorbent polymer microspheres. The abdominal wall retraction method first was applied to avoid the effects of pneumoperitoneum on systemic hemodynamic alterations. However, a sufficient surgical view could not be obtained, as the intra-abdominal organs were elevated because of the enlarged uterus. A surgical view with 4 to 6-mm Hg pneumoperitoneum was available for the hand-assisted splenectomy. The postoperative course was uneventful, and the patient vaginally delivered a healthy infant. A hand-assisted laparoscopic splenectomy with low-pressure pneumoperitoneum after splenic arterial embolization would be feasible for patients with autoimmune thrombocytopenic purpura during a relatively advanced pregnancy.

[Intravascular malignant lymphomatosis: an autopsy case with generalized telangiectasia and various neurological manifestations]

We report a 73-year-old woman with intravascular malignant lymphomatosis (IML) who showed generalized telangiectasia as well as various neurological symptoms. In July 1998, she developed fever, dizziness, and confusion followed by left hemiparesis, and was admitted to our hospital on August 11, 1998. Laboratory tests indicated a normochromic normocytic anemia, thrombocytopenia, elevated serum lactic dehydrogenase (LDH), C-reactive protein (CRP), and cerebrospinal fluid protein. Magnetic resonance imaging (MRI) of the brain revealed an infarct-like lesion in the left frontal lobe and multiple white matter lesions. After admission, her neurological status deteriorated and lapsed into coma and quadriplegia. At the end of September 1998, generalized telangiectasia appeared, and she was diagnosed as IML on skin biopsy. Although combination chemotherapy failed to improve her neurological symptoms, telangiectasia disappeared in a few days, and the infarct-like lesion on MRI decreased in size. Serum LDH, CRP, and thrombocyte counts were normalized. Autopsy findings revealed perivascular clustering of B cell type lymphoma cells in the left frontal lobe where abnormal signal intensity was found on MRI, as well as the spleen and the bone marrow. This case emphasizes the importance of early diagnosis and treatment in IML.

Signal transduction of reactive oxygen species and mitogen-activated protein kinases in cardiovascular disease

Reactive oxygen species (ROS), generated by reduction-oxidation (redox) reactions, have been recognized as important chemical mediators that regulate signal transduction. It has been reported that increase in ROS generation may relate to a risk for cardiovascular diseases such as atherosclerosis, angina pectoris, and myocardial infarction. Therefore, understanding the ROS-generating biological processes and ROS-induced intracellular signaling will be informative to gain insights into the pathogenesis of these diseases. In this review, we focus on the sources and reactions of ROS in the cardiovascular system and the role of mitogen-activated protein (MAP) kinase pathway in redox-mediated signal transduction. Clinical implications of ROS and MAP kinase are then described to provide insight into the pathogenesis of various redox-sensitive cardiovascular diseases. The pathways responsible for ROS generation in the cardiovascular system may provide novel therapeutic targets.

Hypolipidemic effect of NK-104 and other 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors in guinea pigs

Hypolipidemic effects of various HMG-CoA reductase inhibitors (statins) were examined in guinea pigs. After 2-week administration of NK-104 ((+)-monocalcium bis((3R,5S,6E)-7-[2-cyclopropyl-4-(4-fluorophenyl)-3-quinolyl]-3, 5-dihydroxy-6-heptenoate), CAS 147526-32-7), simvastatin (SV), pravastatin (PV), fluvastatin (FV), cerivastatin (CV) and atorvastatin (AV) to guinea pigs at various doses, which did not affect body weight, plasma and liver lipids were measured. Liver endoplasmic reticulum (ER) was isolated and measured for lipid content and activity of ER enzymes (NK-104: 3 mg/kg, SV: 30 mg/kg). Each statin except CV dose-dependently lowered total cholesterol (TC), with NK-104 showing the greatest effect. Only NK-104 and AV, long-acting statins, significantly lowered triglycerides (TG). A significant reduction of the liver cholesterol content was observed for NK-104 and AV. The liver TG content increased with dose for SV or PV, but not for NK-104 or AV. The TG content in ER and activity of diacylglycerol acyltransferase of ER, increased with SV and slightly with NK-104. Activity of microsomal triglyceride transfer protein, which is necessary for both apoB particle formation at rough ER and TG droplet production at smooth ER, increased by SV but not by NK-104. It is suggested that statins with prolonged action lower TG by decreasing cholesterol ester supply necessary for very low density lipoprotein formation and by attenuating an increase in TG production at ER after HMG-CoA reductase inhibition.

Biallelic inactivation of retinoic acid receptor beta2 gene by epigenetic change in breast cancer

A growing body of evidence supports the hypotheses that retinoic acid receptor beta2 (RAR beta2) is a tumor suppressor gene. Although the loss of RAR beta2 expression has been reported in many malignant tumors, including breast cancer, the molecular mechanism is still poorly understood. We hypothesized that loss of RAR beta2 activity could result from multiple factors, including epigenetic modification and loss of heterozygosity (LOH). Using methylation-specific polymerase chain reaction and LOH analysis, we found that biallelic inactivation via epigenetic changes of both maternal and paternal alleles, or epigenetic modification of one allele combined with genetic loss of the remaining allele, could completely suppress RAR beta2 expression in breast cancer. Thus, it is possible that substantial numbers of human cancers arise through suppressor gene silencing via epigenetic mechanisms that inactivate both alleles. Because of this, chromatin-remodeling drugs may provide a novel strategy for cancer prevention and treatment.

Effect of endothelin-1(1-31) on p38 mitogen-activated protein kinase in cultured human mesangial cells

It was reported that human chymase cleaves big endothelins (ETs) at the Tyr31-Gly32 bond and produces 31-amino acid ETs(1-31). In this study, we investigated the effect of ET-1(1-31) on p38 mitogen-activated protein kinase (p38-MAPK) activity in human mesangial cells (HMCs). By measuring the kinase activity, we demonstrated that ET-1 (1-31) activated the p38-MAPK dose-dependently (10(-9) M to 10(-7) M), which was inhibited by SB203580. The p38-MAPK activation induced by ET-1(1-31) peaked at 10 minutes. BQ123 almost abolished ET-1(1-31)-induced p38-MAPK activation, whereas BQ788 failed to inhibit it. These findings suggest that the stimulatory effect of ET-1(1-31) on p38-MAPK activation is mediated through ET(A) or ET(A)-like receptor. In conclusion, ET-1(1-31) induced increase in p38-MAPK activation in cultured HMCs.

A comparative study of surgical approaches for cervical compressive myelopathy

Since 1986, the authors have used anterior decompression and fusion to treat patients with one- or two-level lesions without spinal canal stenosis (Group A) and laminoplasty for patients with more than three-level lesions or spinal canal stenosis (Group P). The aim of this study was to compare surgical outcomes of anterior and posterior approaches for patients with cervical myelopathy because of spondylosis and disc herniation and to determine the cause of poor neurologic recovery after surgery. One hundred thirty-six patients were followed up for an average of 5.6 years. There were no significant differences in gender, preoperative neurologic deficits, axial symptoms, or duration of symptoms before surgery between the two groups. Mean recovery rates for disc herniations were 71.1% and 71.9% in Groups A and P, respectively. For spondylosis, mean recovery rates were 49.0% and 58.6% in Groups A and P, respectively. There were no differences in recovery rate for patients with either spinal disorder between Groups A and P. The neurologic recovery of patients with kyphotic spinal cord was inferior to that of patients with lordotic or straight spinal cord. It is possible that acquisition and maintenance of lordosis result in improvement of clinical outcomes after surgery for patients with myelopathy.