VT recurrence and predictors in patients with VT inducibility at the end of VT ablation

Background

A successful Radiofrequency (RF) ablation of ventricular tachycardia (VT) can prevent VT recurrence. It has been reported that VT non-inducibility at the end of RF ablation is associated with less likely VT recurrence in ischemic cardiomyopathy (ICM) and non-ICM (NCIM). However, it is not clear whether we should use VT non-inducibility as routine end point in RF ablation of VT.

Purpose

The aim of this study was to evaluate VT recurrence in patients who couldn't be achieved VT non-inducibility at the end of RF ablation and the factors attributed to VT recurrence in ICM and NICM patients.

Methods

Between January 2009 and April 2020, 84 consecutive patients (ICM: 34, NICM: 50) underwent RF ablation for drug-resistant VT in our hospital. VT non-inducibility was defined as any ventricular tachy-arrhythmia, including clinical VT, non-clinical VT, and VF, was not induced by programed stimuli at the end of session. Non-inducibility was achieved in 37 patients but it was not achieved in 47 patients (ICM: 18, NICM: 29). To evaluate the validity of “non-inducibility” as an end point of VT ablation, 47 patients (male: 40, mean age: 66±15 years) in whom non-inducibility of any ventricular tachyarrhythmia was not achieved were studied. The primary endpoint was recurrence of any sustained VT and VF during follow up period (mean follow-up period was 1.4 (range, 0.0, 2.0) years.)

Results

Mean left ventricular ejection fraction (LVEF) was 36±13%. Epicardial ablation was required in 8 patients. 32 patients had electrical storm at the time of ablation. Among them, 21 patients had VT recurrence and 26 patients had non-VT recurrence during follow-up period. VT recurrence rate was significantly lower in patients with LVEF≥35% than those with LVEF<35% (HR=0.31, 95% CI 1.25–9.92). Multivariate survival analysis identified LVEF≥35% (HR=0.34, 95% CI 0.10–0.98) and ablation of VT isthmus (HR=0.18, 95% CI 0.02–0.78) as independent predictors of non-VT recurrence.

Conclusions

Even if non-inducibility of any ventricular tachyarrhythmia wasn't achieved at the end of ablation, the patients with LVEF≥35% or who had ablated of VT isthmus might prevent VT recurrence. The validity of non-inducibility of any ventricular tachyarrhythmia should be evaluated in each patient's background.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Abbott, Medtronic

SAT0005 INHIBITION OF HEPATOCYTE GROWTH FACTOR/C-MET SIGNALING ABROGATES JOINT DESTRUCTION BY SUPPRESSING MIGRATION OF MONOCYTES TO SYNOVIUM IN RHEUMATOID ARTHRITIS

Background:

Hepatocyte growth factor (HGF), originally discovered as a mitogen of hepatocytes, binds to receptor-tyrosine kinase c-Met and has been shown to be a multi-functional cytokine that promotes processes such as cell proliferation, survival, differentiation, migration, and angiogenesis1. Since HGF/c-Met signaling also leads to tumorigenesis and cancer invasion, that has recently attracted attention as a target for anticancer agents2. However, in reports of rheumatoid arthritis (RA), though anti-inflammatory and antiangiogenic mechanisms related to HGF/c-Met signal inhibition have been reported, the role of HGF in RA bone destruction through monocyte migration remains unclear3.

Objectives:

To determine the expression of HGF in RA biological fluids, the role it plays in monocyte migration and the therapeutic effect of a savolitinib, a specific c-Met inhibitor, in arthritis model mice.

Methods:

HGF/c-Met expression in serum, synovial fluid (SF), and synovial tissues (STs) obtained from RA patients and control subjects, as well as RA fibroblast-like synoviocytes (FLSs) was evaluated by ELISA and immunostaining. To determine the function of HGF in RA SFs, we preincubated RA SFs with a neutralizing anti-HGF antibody and measured the ability of these SFs to induce the human acute monocytic leukemia cell line (THP-1) chemotaxis. Additionally, examinations of SKG mice treated with savolitinib (2.5 mg/kg/day) for 4 weeks were conducted.

Results:

HGF level in serum from RA patients was significantly higher as compared to the controls (930 ± 97 vs. 476 ± 97 pg/mL, p <0.01) and decreased by drug treatment for 24 weeks (1147 ± 284 vs. 539 ± 160 pg/mL, p <0.05). Additionally, HGF level in SF from RA patients was higher as compared to SF from osteoarthritis patients (1632 ± 366 vs. 566 ± 140 pg/mL, p <0.05). HGF and c-Met expressions were also noted in RA STs. Stimulation of RA-FLS with TNF-α increased HGF/c-Met expression in a concentration-dependent manner, and c-Met signal inhibition by SU11274 suppressed production of fractalkine/CX3CL1, CXCL16, and MIP-1α/CCL3 (mean 50%, 56%, 90%, respectively). When HGF was removed by immunoprecipitation, migration of THP-1 in RA-SF was suppressed (mean 23%). In SKG mice, savolitinib significantly suppressed ankle bone damage on µCT, with an associated reduction in number of tartrate-resistant acid phosphatase-positive osteoclasts.

Conclusion:

HGF is produced by inflammation in synovium associated with RA, and then activates monocyte migration to synovium tissue and promotes bone destruction through its own chemotactic effect as well as enhanced chemokine production. These results indicate that a strategy that targets c-Met signaling may be important for resolving bone destruction in RA.

References:

[1] Nakamura T, Nishizawa T, Hagiya M, Seki T, Shimonishi M, Sugimura A, Tashiro K, Shimizu S. Molecular cloning and expression of human hepatocyte growth factor. Nature. 1989 Nov 23;342(6248):440-3

[2] Lee D, Sung ES, Ahn JH, An S, Huh J, You WK. Development of antibody-based c-Met inhibitors for targeted cancer therapy. Immunotargets Ther. 2015 Feb 9;4:35-44.

[3] Koch AE, Halloran MM, Hosaka S, Shah MR, Haskell CJ, Baker SK, Panos RJ, Haines GK, Bennett GL, Pope RM, Ferrara N. Hepatocyte growth factor. A cytokine mediating endothelial migration in inflammatory arthritis. Arthritis Rheum. 1996 Sep;39(9):1566-75

Disclosure of Interests:

None declared

Minimally invasive spinal decompression for degenerative lumbar spondylolisthesis and stenosis maintains stability and may avoid the need for fusion

Aims

The aim of this study was to investigate the clinical and radiographic outcomes of microendoscopic laminotomy in patients with lumbar stenosis and concurrent degenerative spondylolisthesis (DS), and to determine the effect of this procedure on spinal stability.

Patients and Methods

A total of 304 consecutive patients with single-level lumbar DS with concomitant stenosis underwent microendoscopic laminotomy without fusion between January 2004 and December 2010. Patients were divided into two groups, those with and without advanced DS based on the degree of spondylolisthesis and dynamic instability. A total of 242 patients met the inclusion criteria. There were 101 men and 141 women. Their mean age was 68.1 years (46 to 85). Outcome was assessed using the Japanese Orthopaedic Association and Roland Morris Disability Questionnaire scores, a visual analogue score for pain and the Short Form Health-36 score. The radiographic outcome was assessed by measuring the slip and the disc height. The clinical and radiographic parameters were evaluated at a mean follow-up of 4.6 years (3 to 7.5).

Results

There were no significant differences in the preoperative measurements between the group and no significant differences between the clinical parameters at the final follow-up. The mean percentage slip was 17.1% preoperatively and 17.7% at the final follow-up (p = 0.35). Progressive instability was noted in 13 patients (8.2%) with DS and 6 patients (7.0%) with advanced DS, respectively (p = 0.81). There was radiological evidence of restabilization of the spine in 30 patients (35%) with preoperative instability. The success rate of microendoscopic laminotomy was good/excellent in 166 (69%), fair in 49 (20%) and poor in 27 patients (11%) in both groups.

Conclusion

Microendoscopic laminotomy is an effective form of surgical treatment for patients with DS and stenosis. Preservation of the stabilizing structures using this technique prevents postoperative instability. Cite this article: Bone Joint J 2018;100-B:499-506.

Receptor activator of NF-kappaB ligand induces the fusion of mononuclear preosteoclasts into multinucleated osteoclasts

The osteoclasts are bone-resorbing multinucleatedcells formed by the fusion of mononuclearpreosteoclasts (pOCs) of hematopoietic origin.Although receptor activator of NF-kappaBligand (RANKL) has been shown to regulate osteoclastdifferentiation and function, its effect on the fusionof pOCs into multinucleated osteoclast-like cells(OCLs) has not been known. Using our fusion assaysystem, that is not contaminated with multinucleatedcells (MNCs) and osteoblastic cells, we determined theeffect of RANKL on the fusion of pOCs into MNCs. WhenpOCs were cultured on the plates, most of pOCs diedand disappeared from the plates within 24 h in theabsence of additives, but pOCs were fused to MNCswithin 6 h in the presence of RANKL. RANKL-inducedMNCs showed typical properties of OCL such astartrate-resistant acid phosphatase (TRAP) activity,actin ring formation, and bone-resorbing activity. Thefusion of pOCs into OCLs induced by osteoblastic cellsor RANKL was inhibited by OPG/OCIF, but that inducedby IL-1beta was not. Both RANKL- andIL-1beta-induced OCL formation from pOCs wasinhibited by ZLLL-H, a peptide inhibitor ofproteasome. These findings indicate that RANKLsupports the survival of pOCs and induces the fusionof pOCs into OCLs and suggest that NF-kappaBactivation is involved in these processes induced byRANKL and IL-1beta.

Low affinity IgE receptors: regulation and functional roles in cell activation

The low affinity IgE receptors (Fc epsilon RII/CD23) homologous to animal lectins have the unique property of cleaving-off the extracytoplasmic portion as the soluble form (IgE binding factor; IgE-BF). Molecular analysis using Fc epsilon RII/CD23 cDNA proved that Fc epsilon RII is not unique to B lymphocytes but is expressed on a variety of cell lineages including T lymphocytes, macrophages and eosinophils. In these cell types, IL-4 is a general inducer of this molecule while IFN-gamma down-regulates B cell Fc epsilon RII/CD23 and up-regulates Fc epsilon RII/CD23 on macrophage and eosinophil cell lines. As predicted by the expression of Fc epsilon RII/CD23 in some HTLV-1(+) T cell lines, Fc epsilon RII/CD23 proved to be induced on normal peripheral T lymphocytes by IL-4 or IL-2 in the presence of additional permissive signals. As indicated by IL-2-dependent Fc epsilon RII/CD23 induction, there is an interesting bilateral co-regulation between Fc epsilon RII/CD23 and the 55 kDa chain of the IL-2 receptor complex with Tac antigen (IL-2R/p55(Tac]. Triggering of Fc epsilon RII/CD23 resulted in the enhanced expression of IL-2R/p55(Tac), whereas IL-2 enhanced the expression of Fc epsilon RII/CD23 in some systems. It is suggested that the triggering of cell surface Fc epsilon RII/CD23 by natural ligands is effectively buffered by soluble Fc epsilon RII/CD23 (IgE-BF).

Nitric oxide in pulp cell growth, differentiation, and mineralization

Dental preparation sometimes causes transient congestion, edema, and necrosis of the pulp. We hypothesized that nitric oxide (NO) is involved in the pathophysiological changes in pulp after preparation. The mRNA and protein expression of the inducible isoform of NO synthase (iNOS) was examined in murine pulp after dental preparation. The effects of NO on the proliferation, mineralization, and apoptosis of pulp cells were also studied in vitro. We found that not only iNOS, but also mRNAs for alkaline phosphatase and plasma membrane glycoprotein-1, were expressed in the pulp after preparation. NOC-18, an NO donor, suppressed the proliferation of pulp cells without inducing cell death, whereas it promoted the mineralization of cells cultured in the presence of beta-glycerophosphate, ascorbic acid, dexamethasone, and KH(2)PO(4). Under these conditions, NOC-18 induced the apoptosis of pulp cells. These results suggest that NO regulates the growth, apoptosis, and mineralization of pulp cells.

Destruxins, cyclodepsipeptides, block the formation of actin rings and prominent clear zones and ruffled borders in osteoclasts

Bone-resorbing osteoclasts exhibit polarized morphological structures such as actin rings, clear zones, and ruffled borders. To gain insight into the mechanism of bone-resorbing activity of osteoclast and to discover new types of anti-resorptive agents, we have screened for natural compounds that inhibit the bone-resorbing activity of osteoclast-like multinucleated cells (OCLs). Destruxin B (DestB) and E (DestE), cyclodepsipeptides, were found to inhibit pit formation without affecting osteoclast differentiation and survival. Destruxins reversibly induced morphological changes in OCLs in a dose-dependent manner (DestB, 0.2-1 microM; DestE, 0.01-0.05 microM) and inhibited pit formation. Destruxin-induced morphological changes were accompanied by disruption of the actin rings in OCLs. The formation of actin rings in OCLs after adhesion was also inhibited by destruxins. Electron microscopical analysis revealed that destruxin-treated OCLs on dentine slices have no prominent clear zones and ruffled borders. The effective concentrations of destruxins on the morphological changes were almost the same as those that inhibited bone resorption in organ culture system. These results suggest that the anti-resorptive effects of destruxins result from induction of a disorder of the morphological structures in polarized OCLs.

Involvement of vacuolar H+ -ATPase in incorporation of risedronate into osteoclasts

Although osteoclasts incorporate bisphosphonates during bone resorption, the mechanism of this incorporation by osteoclasts is not known. We previously reported that bisphosphonates disrupt the actin rings (clear zones) formed in normal osteoclasts, but did not disrupt actin rings in osteoclasts derived from osteosclerotic oc/oc mice, which have a defect in the gene encoding vacuolar H(+)-ATPase (V-ATPase). The present study showed that V-ATPase is directly involved in the incorporation of risedronate, a nitrogen containing bisphosphonate, into osteoclasts. Treatment of osteoclasts with risedronate disrupted actin rings and inhibited pit formation by osteoclasts on dentine slices. Bafilomycin A(1), a V-ATPase inhibitor, inhibited the pit-forming activity of osteoclasts but did not disrupt actin rings. Risedronate failed to disrupt actin rings in the presence of bafilomycin A(1). E-64, a lysosomal cysteine proteinase inhibitor, showed no inhibitory effect on the demineralization of dentine by osteoclasts but inhibited the digestion of dentine matrix proteins without disrupting actin rings. Risedronate disrupted actin rings even in the presence of E-64. Treatment of osteoclasts placed on plastic plates with risedronate also disrupted actin rings. Bafilomycin A(1) but not E64 prevented the disruption of actin rings in osteoclasts treated with risedronate on plastic plates. Inhibition of V-ATPase with bafilomycin A(1) also prevented disruption of actin rings by etidronate, a non-nitrogen-containing bisphosphonate. These results suggest that V-ATPase induced acidification beneath the ruffled borders of osteoclasts and subsequent bone demineralization triggers the incorporation of both nitrogen-containing and non-nitrogen-containing bisphosphonates into osteoclasts.

Simple decompression with small skin incision for cubital tunnel syndrome

Eighteen elbows in 17 patients with cubital tunnel syndrome were treated by simple decompression using only a 1.5-2.5 cm skin incision with no endoscopic assistance. According to McGowan's criteria, three elbows were classified preoperatively as grade I, six as grade II and nine as grade III. The mean follow-up period was 14 months (range 3-25). Clinical results were evaluated as excellent for four elbows, good for ten and fair for four. Improvement of symptoms occurred in all patients and dislocation of the ulnar nerve was not observed. Simple decompression through a small skin incision can be recommended for the treatment of cubital tunnel syndrome, if the indication is appropriate.

The bovine fibroblast growth factor receptor 3 (FGFR3) gene is not the locus responsible for bovine chondrodysplastic dwarfism in Japanese brown cattle

Fibroblast growth factor receptor 3 (FGFR3) is one of the four distinct membrane-spanning tyrosine kinase receptors for fibroblast growth factors. The FGFR3 is a negative regulator of endochondral ossification and mutations in the FGFR3 gene have been found in patients of human hereditary diseases with chondrodysplastic phenotypes. Recently, we mapped the locus responsible for hereditary chondrodysplastic dwarfism in Japanese brown cattle to the distal region of bovine chromosome 6 close to the FGFR3 gene, suggesting that FGFR3 was a positional candidate gene for this disorder. In the present study, we isolated complementary DNA (cDNA) clones containing the entire coding region of the bovine FGFR3 gene. Comparison of the nucleotide sequence between affected and normal animals revealed no disease-specific differences in the deduced amino acid sequences. We further refined the localization of FGFR3 by radiation hybrid mapping, which is distinct from that of the disease locus. Therefore we conclude that bovine chondrodysplastic dwarfism in Japanese brown cattle is not caused by mutation in the FGFR3 gene.

Malignant transformation of cerebello-pontine angle epidermoid

A 55-year-old woman presented with fever and a stiff neck due to an intracranial poorly differentiated carcinoma at the right cerebellopontine angle. The patient suffered from typical trigeminal pain and had undergone a removal of the right cerebellopontine angle epidermoid 13 years before at another hospital. On admission, MRI imaging showed a lesion at the right cerebellopontine angle with marked contrast enhancement. Partial removal of the tumor was achieved. A histological examination of the tumor showed a poorly differentiated carcinoma accompanied by typical desquamated tissue of the epidermoid. The patient died 3 months after the operation because of aggressive meningeal carcinomatosis.

Lack of noninvasive markers of ventricular repolarization inhomogeneity in patients with idiopathic ventricular tachyarrhythmia

Noninvasive markers reflecting repolarization inhomogeneity have been proposed to be useful indices for identifying patients at risk of ventricular arrhythmias based on organic heart disease. In this study, we clarify whether or not repolarization inhomogeneity markers are useful in patients with idiopathic ventricular tachycardia (VT). We investigated T-wave alternans (TWA) and corrected QT-interval dispersion (QTD) in 84 consecutive patients with idiopathic VT, 90 patients with VT associated with organic heart disease (organic VT), and 87 normal individuals. VT was defined as tachycardia lasting > or =5 consecutive ventricular ectopic beats at a rate of > or =120 beats/min. TWA was positive in 20 of 84 patients (24%) with idiopathic VT, 59 of 90 patients (66%) with organic VT, and 16 of 87 normal individuals (18%). The alternans voltage was 2.6 +/- 3.1 micro V in idiopathic VT patients, 5.6 +/- 6.4 micro V in organic VT patients, and 2.9 +/- 5.7 micro V in normal individuals. QTD were 53 +/- 20 ms in idiopathic VT patients, 92 +/- 20 ms in organic VT patients, 46 +/- 18 ms in normal individuals, respectively. A positive TWA test result was seen more (P <.01) frequently, and QTD was longer (P <.01) in organic VT patients compared to normal individuals, whereas there was no difference between idiopathic VT patients and normal individuals. In addition, in patients with idiopathic VT, neither did any of these measurements differ between patients with sustained VT (lasting for > or =30 s) and those with nonsustained VT. Noninvasive markers of repolarization inhomogeneity, such as TWA and QTD, are not useful for identifying patients with idiopathic VT. Repolarization inhomogeneity may not affect to the pathogenesis of idiopathic VT.

Clinical usefulness of the combination of T-wave alternans and late potentials for identifying high-risk patients with moderately or severely impaired left ventricular function

Ventricular tachyarrhythmia (VT) is an independent risk factor for an increased overall mortality in patients with impaired left ventricular (LV) function, but there is not an established noninvasive tool to detect such patients. The present study aimed to clarify the most useful noninvasive approach for identification of patients with moderately or severely impaired LV function complicated by VT. Sixty-seven patients in New York Heart Association (NYHA) classes I-III with an LV ejection fraction (LVEF) less than 40% and an LV end-diastolic dimension (LVDD) of at least 55 mm on echocardiography were enrolled. Impaired LV function was caused by either ischemic (n=30) or nonischemic dilated cardiomyopathy (n=37). T-wave alternans (TWA), QT dispersion (QTD), and late potentials (LP) on signal-averaged electrocardiography were sequentially determined without using antiarrhythmic drugs. VT was defined as more than 6 consecutive ventricular ectopic beats. The mean NYHA class was 1.9+/-0.7, mean LVEF was 31+/-8%, and mean LVDD was 65+/-10mm. A history of VT was present in 26 of the patients (39%). Univariate and multivariate logistic analysis showed that TWA and LP were closely related to VT, whereas NYHA> or =III, LVEF<30%, LVDD> or =70mm, and QTD> or =90ms were not. The combination of TWA and LP had the most significant value (p=0.0004, odds ratio=8.44) by univariate analysis, and only this combination had significant value in multivariate analysis (p=0.04). Therefore, the combination of TWA and LP could be a useful index for identifying those patients with impaired LV function who are at risk for VT.

Comparison of T-wave alternans and QT interval dispersion to predict ventricular tachyarrhythmia in patients with dilated cardiomyopathy and without antiarrhythmic drugs: a prospective study

Microvolt T-wave alternans (TWA) and QT interval dispersion (QTD), which reflect temporal and spatial repolarization abnormalities, respectively, have been proposed as useful indices to identify patients at risk for ventricular tachyarrhythmias (VTs). The purpose of this study was to clarify which repolarization abnormality marker is more useful in predicting arrhythmic events in patients with dilated cardiomyopathy (DCM). Forty-two consecutive nonischemic DCM patients underwent the assessment of TWA and QTD. Patients undergoing antiarrhythmic pharmacotherapy, except beta-blockers and those with irregular basic rhythms, were excluded from entry. Eight patients were also excluded because of indeterminate test results. Therefore, 34 DCM patients were prospectively assessed. The end point of the study was the documentation of VT defined as > or = 5 consecutive ectopic beats during the follow-up period. TWA and QTD (> or = 65 msec) were positive in 24 (80%) and 11 (37%) of 30 patients with available follow-up data, respectively. There was no relationship between TWA and QTD. During a follow-up of 13+/-11 months, VTs occurred in 13 patients (43%). In Cox regression analysis, TWA was a significant risk stratifier (p=0.02), whereas QTD was not. The sensitivity, specificity, and positive and negative predictive values of TWA in predicting VTs were 100%, 35%, 54%, and 100%, respectively. TWA could be a useful noninvasive index to identify patients at risk for VTs in the setting of DCM. This study may suggest that temporal repolarization abnormality is associated more with arrhythmogenesis than with spatial repolarization abnormality in DCM patients.

Assessment of noninvasive markers in identifying patients at risk in the Brugada syndrome: insight into risk stratification

OBJECTIVES

The aim of this study was to compare the use of various noninvasive markers for detecting risk of life-threatening arrhythmic events in patients with Brugada syndrome.

BACKGROUND

The role of conduction disturbance in arrhythmogenesis of the syndrome is controversial, whereas it is well established that repolarization abnormalities are responsible for arrhythmias. The value of noninvasive markers reflecting conduction or repolarization abnormalities in identifying patients at risk for significant arrhythmias has not been shown.

METHODS

We assessed late potentials (LP) using signal-averaged electrocardiography (ECG), microvolt T-wave alternans (TWA), and corrected QT-interval dispersion (QTD) in 44 consecutive patients who had ECGs showing a pattern of right bundle branch block and ST-segment elevation in leads V1 to V3 but structurally normal hearts. The patients were compared with 30 normal individuals.

RESULTS

Eleven patients were excluded from data analysis because of an absence of ECG manifestations of Brugada syndrome at the time of the tests. A history of life-threatening events defined as syncope and aborted sudden death was present in 19 of 33 patients (58%); in 15 of the 19 patients, stimulation induced ventricular fibrillation or polymorphic ventricular tachycardia. The LP were present in 24 of 33 patients (73%); TWA were present in 5 of 31 patients (16%); and a QTD >50 ms was present in 9 of 33 patients (27%). The incidence of LP in Brugada patients was significantly (p < 0.0001) higher than in the controls, whereas incidences of TWA and QTD were not significantly different. Multivariate logistic regression analysis revealed that the presence of LP had the most significant correlation to the occurrence of life-threatening events (p = 0.006).

CONCLUSIONS

Late potentials are a noninvasive risk stratifier in patients with Brugada syndrome. These results may support the idea that conduction disturbance per se is arrhythmogenic.

Mac-1-dependent tyrosine phosphorylation during neutrophil adhesion

Activated neutrophils display an array of physiological responses, including initiation of the oxidative burst, phagocytosis, and cell migration, that are associated with cellular adhesion. Under conditions that lead to cellular adhesion, we observed rapid tyrosine phosphorylation of an intracellular protein with an approximate relative molecular mass of 92 kDa (p92). Phosphorylation of p92 was inducible when Mac-1 was activated by phorbol 12-myristate 13-acetate, the beta(2)-specific activating antibody CBR LFA-1/2, or interleukin-8 (77 amino acids). In addition, tyrosine phosphorylation of p92 was dependent on engagement of Mac-1 with ligand. Several observations suggest that this event may be an important step in the signaling pathway initiated by Mac-1 binding. p92 phosphorylation was specifically blocked with antibodies to CD11b, the alpha-subunit of Mac-1, and was rapidly reversible on disengagement of the integrin ligand interaction. Integrin-stimulated phosphorylation of p92 created binding sites that were recognized in vitro by the SH2 domains of c-CrkII and Src. Our observations suggest that neutrophil adhesion mediated through the binding of the beta(2)-integrin Mac-1 initiates a signaling cascade that involves the activation of protein tyrosine kinases and leads to the regulation of protein-protein interactions via SH2 domains, a key process shared with growth factor signaling pathways.

Prognostic factors for recurrence in stage II and III gastric cancer patients receiving a curative resection and postoperative adjuvant chemotherapy

Prognostic value of clinicopathologic factors and biologic markers was analyzed in 185 patients who received a curative resection and adjuvant chemotherapy of pathologically confirmed stage II or III gastric cancer. No difference was found between the chemotherapeutic regimens according to the frequency of recurrence, but tumor type, histology, depth of invasion, nodal metastasis, and lymphatic and venous invasion were significantly different between recurrent (n=62) and non-recurrent (n=123) patients. However, the degree of lymphatic dissection and the patterns of biological markers (DNA ploidy, p53 staining and PCNA labeling) were not different. Hepatic metastasis and venous invasion were more frequent on patients recurring within one year, compared to those who recurred later. Multivariate analyses showed that depth of invasion, level 2 lymph node metastasis and tumor histology were risk factors for recurrence. Pathologic factors were more important for predicting recurrence than biological markers.

[Patient compliance and the quality of life are well maintained in weekly paclitaxel and carboplatin therapy for advanced gynecologic cancers in Japanese women]

OBJECTIVES

To assess patient compliance and efficacy of a combination chemotherapy consisting of weekly administration of paclitaxel and carboplatin for gynecologic malignancy in Japanese women.

METHODS

Fourteen ovarian and three uterine cancer patients received 80 mg/m2 of paclitaxel (paclitaxel) and AUC 1.5 to 2.0 of carboplatin weekly. The toxicity was evaluated and patients' QOL was tested.

RESULTS

Neutropenia higher than grade 3 were observed in 29.4%. Four patients received G-CSF support. Grade 1 neurotoxicity was seen in 76.5% of patients. Evaluation of QOL by EORTC-QLQC30 showed significantly better tolerance of a weekly than monthly regimen. Three out of four patients with lung metastasis showed complete disappearance of the lesions. One patient with stage IIIb cervical cancer underwent postchemotherapy-hysterectomy and a complete pathological response was confirmed. The overall response rate was 64.7% including patients previously treated with platinum based multidrug regimens.

CONCLUSIONS

A weekly paclitaxel and carboplatin regimen was well tolerated by Japanese women. The regimen was active in over 60% of cases and it also appeared active in multidrug resistant cases.

Intracellular calcium and protein kinase C mediate expression of receptor activator of nuclear factor-kappaB ligand and osteoprotegerin in osteoblasts

Receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) produced by osteoblasts/stromal cells are involved as positive and negative regulators in osteoclast formation. Three independent signals have been proposed to induce RANKL expression in osteoblasts/stromal cells: vitamin D receptor-, cAMP-, and gp130-mediated signals. We previously reported that intracellular calcium-elevating compounds such as ionomycin, cyclopiazonic acid, and thapsigargin induced osteoclast formation in cocultures of mouse bone marrow cells and primary osteoblasts. Increases in calcium concentration in culture medium also induced osteoclast formation in cocultures. Treatment of primary osteoblasts with these compounds or with high calcium medium stimulated the expression of both RANKL and OPG messenger RNAs (mRNAs). 1,2-Bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid)-tetra(acetoxymethyl)ester, an intracellular calcium chelator, suppressed both ionomycin-induced osteoclast formation in cocultures and expression of RANKL and OPG mRNAs in primary osteoblasts. Phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C, also stimulated osteoclast formation in these cocultures and the expression of RANKL and OPG mRNAs in primary osteoblasts. Protein kinase C inhibitors such as calphostin and staurosporin suppressed ionomycin- and PMA-induced osteoclast formation in cocultures and expression of RANKL and OPG mRNAs in primary osteoblasts. Ionomycin stimulated RANKL mRNA expression in ST2 and MC3T3-G2/PA6 cells, but not in MC3T3-E1 or NIH-3T3 cells. These effects were closely correlated with osteoclast formation in response to ionomycin in cocultures with these stromal cell lines. OPG strongly inhibited osteoclast formation induced by calcium-elevating compounds and PMA in cocultures, suggesting that RANKL expression in osteoblasts is a rate-limiting step for osteoclast induction. Forskolin, an activator of cAMP signals, also stimulated osteoclast formation in cocultures. Forskolin enhanced RANKL mRNA expression but suppressed OPG mRNA expression in primary osteoblasts. These results suggest that the calcium/protein kinase C signal in osteoblasts/stromal cells is the fourth signal for inducing RANKL mRNA expression, which, in turn, stimulates osteoclast formation.

[Successful TS-1 therapy in a patient with non-resectable gastric cancer and renal dysfunction]

A 73-year-old woman presented to our hospital with epigastric pain and swelling of the left upper limb. Enlarged lymph nodes with adhesion were palpable in the left cervical region and supraclavicular fossa. Tests were performed with the thought that the left upper limb swelling was secondary to venous compression by the enlarged lymph nodes. Gastroscopy detected a torose lesion on the anterior wall at the gastric angle and biopsy revealed that it was moderately differentiated adenocarcinoma. MRI showed metastasis to the sixth cervical vertebra and the first thoracic vertebra. Based on these findings, she was diagnosed as having progressive gastric cancer with metastasis to Virchow's lymph node and the cervical and thoracic vertebrae. Because it was considered impossible to perform radical gastrectomy, chemotherapy was given. Since renal dysfunction was suggested by a serum Cr of 1.5 mg/ml and a Ccr of 26.2 ml/min, TS-1 was administered at a lower dose (50 mg/day for 4 weeks) than usual, followed by 2 weeks off therapy to complete 1 course. During TS-1 therapy, the plasma 5-FU concentration at 4 h was 129.5 ng/ml, indicating that an effective plasma level of the drug was achieved. TS-1 therapy was considered effective because it reduced the diameter of the primary tumor and the lymph node metastasis, with only mild adverse reactions including myelosuppression.

Luteinizing hormone depletes ascorbic acid in preovulatory follicles

OBJECTIVE

The objective of the present studies was to determine whether luteinizing hormone (LH) depletes ascorbic acid in the preovulatory follicle.

DESIGN

Controlled, prospective experimental study.

SETTING

University-based research center.

ANIMAL(S)

Sprague-Dawley female rats.

INTERVENTION(S)

Follicular growth and ovulation were induced in immature rats by gonadotropin treatment.

MAIN OUTCOME MEASURE(S)

Analysis of ovary, follicle, and oocyte levels of ascorbic acid by colorimetric analysis and high-pressure liquid chromatography.

RESULT(S)

Ovarian ascorbic acid was maximally depleted (50%) within 2 h of LH treatment and was sustained for 8 h. Follicle ascorbic acid levels were unchanged 1 h after LH injection but were significantly reduced within 2 h (40%). Incubation of isolated preovulatory follicles for 3 h with hCG or with menadione (a generator of oxygen radicals) reduced ascorbic acid levels. Isolation of cumulus-enclosed or denuded oocytes depleted ascorbic acid to undetectable levels, but follicular ascorbic acid levels were only moderately depleted by isolation and incubation. Accumulation of ascorbic acid by oocytes was significantly enhanced by the presence of intact cumulus cells.

CONCLUSION(S)

Elevation of LH and the production of oxygen radicals deplete ascorbic acid in the preovulatory follicle.

Atrial double potentials associated with the elimination of the electrical connection between the coronary sinus (CS) and the left atrium in two cases of Wolff-Parkinson-White syndrome with a CS-connected accessory pathway

A curious retrograde conduction in connection with the coronary sinus (CS) musculature was observed in 2 patients. After the failed ablation procedure, the atrial electrogram during ventricular pacing presented double potentials, the first component of which was sharp and with an activation sequence that was the same before ablation (CS distal to proximal). The second component of the double potentials was dull and had a decremental property; its activation sequence was in reverse (proximal to distal). In both cases, the first component disappeared after successful ablation. These findings suggest that the first component was the CS electrogram conducted over the accessory pathway and the second component was the left atrial electrogram conducted through the inter-atrial septum. The separation of each electrogram is probably the result of a block between the accessory pathway connected to the CS musculature and the left atrium. These are unusual cases of an accessory pathway connected to the CS musculature, which separates the left atrial myocardium at the distal portion from the ostium.

[Three long surviving patients with gastric cancer metastasizing to the liver under interdisciplinary therapy]

In 30 patients with gastric cancer metastasizing to the liver over the past 15 years at our hospital the primary foci in the stomach could be resected in a curative manner. The authors report herein three long surviving patients in this series. [Case 1] A 49-year-old male. Distal gastrectomy was performed in November 1984. Metastasis to the liver occurred in June 1986. The right lobe of the liver was resected in November 1987 after transcatheter arterial embolization (TAE). Although hepatic arterial infusion chemotherapy was conducted, the cancer metastasized to the whole body, and the patient died in December 1991. [Case 2] A 65-year-old female. Distal gastrectomy was performed in July 1994. The left hepatic lobe and segment 5 in the right lobe were resected in June 1995. Although TAE was performed six times starting in December 1996, the patient died of hepatic failure in July 1999. [Case 3] A 73-year-old male. This patient simultaneously received distal gastrectomy and extended resection of the posterior hepatic segments in September 1997. Cancer recurred in the remaining liver in July 1998. Although microwave coagulation therapy (MCT) and TAE were performed, the patient died of hepatic failure in January 2000. In these patients who survived for a long period, the primary focus was well-differentiated adenocarcinoma under sufficient local control with metastasis limited to the nearest regional lymph nodes (group 1 lymph nodes). The patients could undergo interdisciplinary therapy, including hepatectomy, MCT, TAE, and hepatic arterial infusion chemotherapy.

[A case report of intra-thoracic biliary fistula after percutaneous microwave coagulation therapy]

Among the locoregional therapies for hepatic malignant tumor, percutaneous microwave coagulation therapy (PMCT) has spread widely as a minimally invasive therapy. We performed PMCT on 40 patients under hepatic blood flow interruption with the aim of improving the radical treatment and expanding the coagulation area by single microwave delivery. A patient with a 2.5 cm lesion in S5 of the liver under PMCT transdiaphragmatically, but he developed a postoperative biliary fistula with consequent development of an intra-thoracic abscess through the diaphragm. Biliary fisture and liver abscess disappeared with open drainage under thoracotomy and laparotomy. Liver abscess has occasionally been reported as a PMCT complication, whereas there have been no reports, to the authors' knowledge, about intra-thoracic abscess as a PMCT complication, as in our case. It should be kept in mind that the penetration of the diaphragm as a route for PMCT may result in a biliary fistula flowing into the thorax, leading to a very serious condition.

[Transcatheter arterial chemo-embolization using degradable starch microspheres (DSM) markedly effective for post-hepatectomy intra-hepatic recurrence in a patient with cholangioma]

Transcatheter arterial chemo-embolization (TACE) using degradable starch microspheres (DSM) was performed for multiple recurrence after hepatectomy in a patient with cholangiocarcinoma. The patient was a 68-year-man. He received treatment for hepatitis type C starting in 1996 at a nearby hospital. In November 1997, an increased AFP level was noted and a CT scan of the abdomen revealed an abnormal shadow in the liver. On May 21, 1998, imaging results led to the diagnosis of cholangiocarcinoma or a mixed type of hepatocellular carcinoma with cholangioma. Hepatic S7 sub-sequential resection was performed. The lesion was found to be a tumor-forming type, measuring 2.2 x 2.0 cm in diameter, diagnosed histopathologically as cholangiocarcinoma, tw (-), but Stage III since a nodule suggesting intrahepatic metastasis was noted in the cut surface of the resected liver. CT scan after a month revealed multiple metastatic lesions in the liver. TACE was performed by administering 450 mg of DSM, 10 mg of MMC and 30 mg of FARM, given in three divided doses on October 30, 1998, and February 9, 1999, according to Seldinger's method. A CT scan on January 31, 2000 revealed nearly complete remission of the hepatic SOL. Accordingly, TACE was considered to be useful therapy in combination with DSM, MMC and FARM for intrahepatic recurrence of cholangiocarcinoma.

[Assessment of colorectal cancer patients exhibiting bilobular multiple hepatic metastases]

We assessed 23 patients who underwent surgical therapy of hepatectomy or microwave coagulation therapy (MCT) for bilobular multiple hepatic metastatic foci following curative resection of the primary lesion of colorectal cancer. Hepatectomy was the first surgical therapy for 10 patients, and 6 of them received combined intra-arterial chemotherapy. All 13 patients in the MCT group received intra-arterial chemotherapy, and 8 of them underwent combined hepatectomy. The two-year survival rate of the hepatectomy group, classified according to the first surgical therapy, was 40% against 52% in the MCT group. In comparison with the H2 (2-5 foci) patients in the hepatectomy group, there were 7 H2 patients in the MCT group, and the two-year survival rate of these 7 patients was 50%. No significant difference was observed between hepatectomy and the MCT as the first surgical therapy. The survival rates of the 5 patients who received treatment for recurrence after the first surgery and of the 18 patients without any recurrence treatment were 80% and 40%, respectively. No significant difference existed between the two groups, but a p value of 0.06 was noted. MCT was considered to be useful local therapy for cancer as the first therapy and as a therapy following recurrence.

A new assay for lipiodol in a tumor using a combination of m-chloroperbenzoic acid-mediated oxidation and the iodo-starch reaction

Lipiodol, an iodine adduct lipid, has been used as a targeting carrier of anticancer drugs in experimental animals and humans. In most studies, the concentrations of the anticancer drugs in tissues and organs have been monitored, but not of the carrier because a simple method for measuring lipiodol in biological organs did not exist. Here we present an analytical method for the quantitative determination of lipiodol in tissue. This method is based on the measurement of iodine released from lipiodol by an oxidative reaction. The released iodine was measured spectrophotometrically by monitoring the iodo-starch reaction. Using this method, we were able to demonstrate the tumor specificity of lipiodol using rabbits bearing VX2 tumors in the liver. The present method is also expected to be applicable to human cancers, such as hepatic and colon cancer.

A deletion of the paracellin-1 gene is responsible for renal tubular dysplasia in cattle

Various hereditary diseases analogous to particular human heritable diseases have been identified in cattle. Investigation of these cattle diseases will provide useful information regarding the pathogenesis of the corresponding human diseases. Renal tubular dysplasia is an autosomal recessive disease of Japanese black cattle characterized by renal failure and growth retardation. We have previously mapped the locus responsible for the disease within a region on bovine chromosome 1. In the present study, we further typed additional markers in this region and found that a genomic segment of bovine chromosome 1 including the microsatellite marker BMS4009 was deleted in the affected animals. Construction of a physical map covering this region with BAC clones and comparison of the nucleotide sequences of this region between normal and affected animals revealed that a region of 37 kb including exons 1 to 4 of the bovine paracellin-1 gene was deleted in the affected animals. The paracellin-1 gene, which is the causative gene for human renal hypomagnesemia with hypercaciuria and nephrocalcinosis, encodes a tight junction protein of renal epithelial cells. Therefore, we concluded that deletion of the paracellin-1 gene is responsible for renal tubular dysplasia of cattle, and the cattle disease could be a good model for the human disease.

Endovascular treatment of unusual multiple aneurysms of the internal carotid artery-posterior communicating artery complex--case report

A 79-year-old female presented with subarachnoid hemorrhage due to rupture of a rare true posterior communicating artery (PCoA) aneurysm and with poor general condition. Endovascular therapy was performed in the chronic stage. Right carotid angiography just before embolization demonstrated unusual multiple aneurysms of the internal carotid artery (ICA)-PCoA complex. Superselective angiography and aneurysmography using microcatheter revealed two separate aneurysms arising from the PCoA and the ICA-PCoA junction. Endovacular embolization using Guglielmi detachable coils (GDCs) was successfully performed for both aneurysms and complete occlusions were achieved with the PCoA fully patent. Embolization with GDCs is a good alternative to surgical clipping for PCoA aneurysm after careful evaluation of superselective angiography.

Importance of membrane- or matrix-associated forms of M-CSF and RANKL/ODF in osteoclastogenesis supported by SaOS-4/3 cells expressing recombinant PTH/PTHrP receptors

SaOS-4/3, a subclone of the human osteosarcoma cell line SaOS-2, established by transfecting the human parathyroid hormone/parathyroid hormone-related protein (PTH/PTHrP) receptor complementary DNA (cDNA), supported osteoclast formation in response to PTH in coculture with mouse bone marrow cells. Osteoclast formation supported by SaOS-4/3 cells was completely inhibited by adding either osteoprotegerin (OPG) or antibodies against human macrophage colony-stimulating factor (M-CSF). Expression of messenger RNAs (mRNAs) for receptor activator of NF-kappaB ligand/osteoclast differentiation factor (RANKL/ODF) and both membrane-associated and secreted forms of M-CSF by SaOS-4/3 cells was up-regulated in response to PTH. SaOS-4/3 cells constitutively expressed OPG mRNA, expression of which was down-regulated by PTH. To elucidate the mechanism of PTH-induced osteoclastogenesis, SaOS-4/3 cells were spot-cultured for 2 h in the center of a culture well and then mouse bone marrow cells were uniformly plated over the well. When the spot coculture was treated for 6 days with both PTH and M-CSF, osteoclasts were induced exclusively inside the colony of SaOS-4/3 cells. Osteoclasts were formed both inside and outside the colony of SaOS-4/3 cells in coculture treated with a soluble form of RANKL/ODF (sRANKL/sODF) in the presence of M-CSF. When the spot coculture was treated with sRANKL/sODF, osteoclasts were formed only inside the colony of SaOS-4/3 cells. Adding M-CSF alone failed to support osteoclast formation in the spot coculture. PTH-induced osteoclast formation occurring inside the colony of SaOS-4/3 cells was not affected by the concentration of M-CSF in the culture medium. Mouse primary osteoblasts supported osteoclast formation in a similar fashion to SaOS-4/3 cells. These findings suggest that the up-regulation of RANKL/ODF expression is an essential step for PTH-induced osteoclastogenesis, and membrane- or matrix-associated forms of both M-CSF and RANKL/ ODF are essentially involved in osteoclast formation supported by osteoblasts/stromal cells.

Microwave coagulation therapy for multiple hepatic metastases from colorectal carcinoma

BACKGROUND

Compared with other treatments, microwave coagulation is a relatively less invasive treatment for various kinds of solid tumors. Although its effectiveness in primary hepatocellular carcinoma has been shown, its effectiveness in the treatment of hepatic metastases from colorectal carcinoma has been unclear. The aim of this study was to evaluate its effectiveness in the treatment of multiple hepatic metastases from colorectal carcinoma by comparing this technique with that of hepatic resection.

METHODS

Thirty patients with multiple metastatic colorectal tumors in the liver who were potentially amenable to hepatic resection were randomly assigned to treatment with microwave coagulation (14 patients) or hepatectomy (16 patients). Tumors in the microwave group were coagulated after laparotomy at an output of 60-100 W for 2-20 minutes under the guide of ultrasonography, whereas tumors in the hepatectomy group were treated with lobectomy, segmentectomy, subsegmentectomy, and/or wedge resection.

RESULTS

One-, 2-, and 3-year survival rates and mean survival times were 71%, 57%, 14%, and 27 months, respectively, in the microwave group, whereas they were 69%, 56%, 23%, and 25 months, respectively, in the hepatectomy group. The difference between these two groups was statistically not significant (P = 0.83). On the other hand, the amount of intraoperative blood loss in the microwave group (360 +/- 230 mL) was smaller than that in the hepatectomy group (910 +/- 490 mL, P < 0.05). Blood transfusion was necessary for 6 patients in the hepatectomy group, but it was not necessary in the microwave group.

CONCLUSIONS

Microwave coagulation therapy is suggested to be equally effective as hepatic resection in the treatment of multiple (two to nine) hepatic metastases from colorectal carcinoma, whereas its surgical invasiveness is less than that of hepatic resection.