Incidence and clinical significance of inducible atrial tachycardia in patients with atrioventricular nodal reentrant tachycardia

INTRODUCTION

The purpose of this prospective study was to determine the prevalence and clinical significance of inducible atrial tachycardia in patients undergoing slow pathway ablation for AV nodal reentrant tachycardia who did not have clinically documented episodes of atrial tachycardia.

METHODS AND RESULTS

Twenty-seven (15%) of 176 consecutive patients who underwent slow pathway ablation for AV nodal reentrant tachycardia were found to have inducible atrial tachycardia with a mean cycle length of 351+/-95 msec. The atrial tachycardia was sustained in 7 (26%) of 27 patients and was isoproterenol dependent in 20 patients (74%). The atrial tachycardia was not ablated or treated with medications, and the patients were followed for 9.7+/-5.8 months. Six (22%) of the 27 patients experienced recurrent palpitations during follow-up. In one patient each, the palpitations were found to be due to sustained atrial tachycardia, nonsustained atrial tachycardia, recurrence of AV nodal reentrant tachycardia, paroxysmal atrial fibrillation, sinus tachycardia, and frequent atrial premature depolarizations. Thus, only 2 (7%) of 27 patients with inducible atrial tachycardia later developed symptoms attributable to atrial tachycardia.

CONCLUSION

Atrial tachycardia may be induced by atrial pacing in 15% of patients with AV nodal reentrant tachycardia. Because the vast majority of patients do not experience symptomatic atrial tachycardia during follow-up, treatment for atrial tachycardia should be deferred and limited to the occasional patient who later develops symptomatic atrial tachycardia.

Three-dimensional structure of human RNase 1 delta N7 at 1.9 A resolution

Human pancreatic ribonuclease 1 (RNase 1) is considered to be the human counterpart of bovine pancreatic RNase A. Truncation of seven amino-acid residues from the amino-terminal sequence resulted in RNase 1 Delta N7, which has a reduced ribonucleolytic activity and a lower affinity for the human placental RNase inhibitor (PRI). This RNase 1 variant has been cloned, heterologously overexpressed, purified and crystallized. Its crystal structure has been determined and refined using data to 1.9 A resolution. The molecule displays the alpha + beta folding topology typical of members of the RNase A superfamily. The main distinct features found in RNase 1 Delta N7 are basically located in three loops affecting the fitting of the enzyme to the active site of subtilisin and the shape of the B2 subsite. These changes, taken with the lack of the catalytically active residue Lys7, may explain the reduced affinity of RNase 1 Delta N7 for PRI and the low ribonucleolytic activity of the protein when compared with the native enzyme.

E-cadherin expression in wound healing of mouse skin

BACKGROUND

E-cadherin has been studied extensively in other systems but little attention has been paid to its role in wound healing. We investigated E-cadherin expression in epithelial wound healing in vivo by focusing on the migrating cells in the epithelial tongue and the mitotic cells in the non-injured side apart from the original wound edge.

METHODS

Round full-thickness excisional wounds (6 mm in diameter) and full-thickness incisional wounds were prepared dorsally in mice. On various days after the operation, E-cadherin expression was examined by immunohistochemical staining using a monoclonal antibody specific for E-cadherin.

RESULTS

In both models, the level of E-cadherin expression did not decrease on the 1st postoperative (P.O.) day. After the 2nd P.O. day, E-cadherin expression decreased in cells at a site 500 microm apart from the original wound edge. After the 3rd P.O. day, decreased expression was also observed in cells at the top and in the basal layer of the epithelial tongue. This decreased expression continued for 1 or 2 days after the meeting of the epithelial tongue. There was no significant difference in the expression of E-cadherin between two models.

CONCLUSIONS

The results suggested that E-cadherin expression decreases in epithelial cells. This decrease may depend on the activity of migration and mitosis. In addition, the change was similar in both the excisional and incisional wounds.

Electrogram polarity and cavotricuspid isthmus block during ablation of typical atrial flutter

INTRODUCTION

The atrial activation sequence around the tricuspid annulus has been used to assess whether complete block has been achieved across the cavotricuspid isthmus during radiofrequency ablation of typical atrial flutter. However, sometimes the atrial activation sequence does not clearly establish the presence or absence of complete block. The purpose of this study was to determine whether a change in the polarity of atrial electrograms recorded near the ablation line is an accurate indicator of complete isthmus block.

METHODS AND RESULTS

Radiofrequency ablation was performed in 34 men and 10 women (age 60 +/- 13 years [mean +/- SD]) with isthmus-dependent, counterclockwise atrial flutter. Electrograms were recorded around the tricuspid annulus using a duodecapolar halo catheter. Electrograms recorded from two distal electrode pairs (E1 and E2) positioned just anterior to the ablation line were analyzed during atrial flutter and during coronary sinus pacing, before and after ablation. Complete isthmus block was verified by the presence of widely split double electrograms along the entire ablation line. Complete bidirectional isthmus block was achieved in 39 (89%) of 44 patients. Before ablation, the initial polarity of E1 and E2 was predominantly negative during atrial flutter and predominantly positive during coronary sinus pacing. During incomplete isthmus block, the electrogram polarity became reversed either only at E2, or at neither E1 nor E2. In every patient, the polarity of E1 and E2 became negative during coronary sinus pacing only after complete isthmus block was achieved. In 4 patients (10%), the atrial activation sequence recorded with the halo catheter was consistent with complete isthmus block, but the presence of incomplete block was accurately detected by inspection of the polarity of E1 and E2.

CONCLUSION

Reversal of polarity in bipolar electrograms recorded just anterior to the line of isthmus block during coronary sinus pacing after ablation of atrial flutter is a simple, quick, and accurate indicator of complete isthmus block.

Canine ventricular myocytes possess a renin-angiotensin system that is upregulated with heart failure

Ventricular pacing leads to a dilated myopathy in which cell death and myocyte hypertrophy predominate. Because angiotensin II (Ang II) stimulates myocyte growth and triggers apoptosis, we tested whether canine myocytes express the components of the renin-angiotensin system (RAS) and whether the local RAS is upregulated with heart failure. p53 modulates transcription of angiotensinogen (Aogen) and AT(1) receptors in myocytes, raising the possibility that enhanced p53 function in the decompensated heart potentiates Ang II synthesis and Ang II-mediated responses. Therefore, the presence of mRNA transcripts for Aogen, renin, angiotensin-converting enzyme, chymase, and AT(1) and AT(2) receptors was evaluated by reverse transcriptase-polymerase chain reaction in myocytes. Changes in the protein expression of these genes were then determined by Western blot in myocytes from control dogs and dogs affected by congestive heart failure. p53 binding to the promoter of Aogen and AT(1) receptor was also determined. Ang II in myocytes was measured by ELISA and by immunocytochemistry and confocal microscopy. Myocytes expressed mRNAs for all the constituents of RAS, and heart failure was characterized by increased p53 DNA binding to Aogen and AT(1). Additionally, protein levels of Aogen, renin, cathepsin D, angiotensin-converting enzyme, and AT(1) were markedly increased in paced myocytes. Conversely, chymase and AT(2) proteins were not altered. Ang II quantity and labeling of myocytes increased significantly with cardiac decompensation. In conclusion, dog myocytes synthesize Ang II, and activation of p53 function with ventricular pacing upregulates the myocyte RAS and the generation and secretion of Ang II. Ang II may promote myocyte growth and death, contributing to the development of heart failure.

Influence of breast-feeding on the production of cytokines

PROBLEM

Recently, we reported increases in the production of interferon-gamma (IFN-gamma), interleukin-2 (IL-2), and IL-4 during the postpartum period. The present study was undertaken to investigate whether these increases might be explained by increased prolactin while breast-feeding.

METHOD

Whole blood from 41 women who were breast-feeding, 13 women not breast-feeding, and 31 healthy non-pregnant women was stimulated with phorbol 12-myristate 13-acetate and ionomycin, and the levels of cytokines in the supernatant were measured by enzyme-linked immunosorbent assay. Their serum levels of prolactin were measured by enzyme immunoassay.

RESULTS

Increases in IFN-gamma, IL-2, IL-4, and IL-10 production were observed in women who were breast-feeding but not in women who were not breast-feeding. Serum levels of prolactin correlated with the levels of IFN-gamma in culture supernatant.

CONCLUSIONS

These results suggest that breast-feeding induces production of cytokines and that IFN-gamma production is enhanced by physiological concentrations of prolactin.

Role of transisthmus conduction intervals in predicting bidirectional block after ablation of typical atrial flutter

INTRODUCTION

Complete bidirectional cavotricuspid isthmus block is the endpoint for ablation of typical atrial flutter. The purpose of this study was to determine whether the extent of prolongation of the transisthmus interval after ablation predicts complete bidirectional block.

METHODS AND RESULTS

Fifty-seven consecutive patients underwent 60 ablation procedures for isthmus-dependent atrial flutter. The clockwise and counterclockwise transisthmus intervals were determined before and after ablation during pacing from the low lateral right atrium and the coronary sinus. Bidirectional block was achieved with ablation in 55 (96%) of 57 patients. The transisthmus intervals before ablation and after complete transisthmus block were 100.3 +/- 21.1 msec and 195.8 +/- 30.1 msec, respectively, in the clockwise direction (P < 0.0001), and 98.2 +/- 24.7 msec and 185.7 +/- 33.9 msec, respectively, in the counterclockwise direction (P < 0.0001). An increase in the transisthmus interval by > or = 50% in both directions after ablation predicted complete bidirectional block with 100% sensitivity and 80% specificity. The positive and negative predictive values were 89% and 100%, respectively. The diagnostic accuracy of a > or = 50% prolongation in the transisthmus interval was 92%.

CONCLUSION

Prolongation of the transisthmus interval by > or = 50% in the clockwise and counterclockwise directions is associated with a high degree of diagnostic accuracy and an excellent negative predictive value in determining complete bidirectional transisthmus block. This may be a useful and simple adjunctive criterion for assessment of complete transisthmus conduction block.

Lip reconstruction of comparatively large defect including the commissure using remaining lip tissue: a modification of reconstructed method

We present two reconstructed cases after malignant skin tumor of comparatively large defects of lip including the commissure using remaining lip tissue alone. After resecting a tumor including wedge-shaped full-thickness lip tissue, a full thickness oblique incision is made at the site 5 mm distant from the contralateral commissure. The rhomboid-shaped lower lip flap is created, transposed to the defect, and sutured with the defect margin, including the upper lip, to reconstruct the commissure. The cross lip flap is created at the contralateral side of the lower lip, 5 mm from the commissure, and the defect is closed with the crosslip flap. Although our method is applicable only to selected cases, we believe that it is useful in terms of maintaining symmetry of the lip and function of the commissure in the reconstruction of comparatively large defects including the commissure.

Prognosis of non-small cell lung cancer patients with positive pleural lavage cytology after a thoracotomy: results of the survey conducted by the Japan Clinical Oncology Group

OBJECTIVE

The purpose of this study was to clarify the prognosis of non-small cell lung cancer patients without pleural effusion whose intrapleural cancer cells were detected by a cytologic examination of pleural lavage fluid obtained immediately after a thoracotomy.

METHOD

A questionnaire survey on the survival of the patients with positive pleural lavage cytology from January 1985 to December 1994 was performed by the Japan Clinical Oncology Group.

RESULTS

According to the data collected from 15 institutions, 1890 non-small cell lung cancer patients without pleural effusion underwent pleural lavage cytology immediately after thoracotomy and 142 (7.8%) of them were found to have intrapleural cancer cells detected by the cytological analysis. The information of survival on 113 patients was available. This comprised of 64 males and 49 females with a mean age of 64.6 years. The predominant histologic type was adenocarcinoma (74%). Out of these 113 patients, 109 (97%) underwent a surgical resection. The 5-year survival rate was 30% in all patients, 49% in pathological stage I (n=35), 23% in stage II (n=20) and 26% in stage IIIA (n=34).

CONCLUSION

Patients with a positive pleural lavage cytology in pathological stage I or II appear to have a poor 5-year survival rate.

Ultrathin SiO(x) Film Coating Effect on the Wettability Change of TiO(2) Surfaces in the Presence and Absence of UV Light Illumination

Wettability of sol-gel TiO(2) film surfaces has been studied by following the H(2)O contact angle (straight theta) as functions of illumination time and subsequent dark storage time. Upon illumination of the TiO(2) surface (lambda(ex)>300 nm), the value of straight theta rapidly decreased to reach approximately zero (photoprocess). When the resultant superhydrophilic sample was stored in the dark, the straight theta value increased slowly with increasing storage time (dark process). Ultrathin SiO(x) films were formed on the surface of TiO(2) by repeating chemisorption of 1,3,5,7-tetramethylcyclotetrasiloxane and its photooxidation. With increasing thickness of the SiO(x) monolayer coating, the rate for the dark process significantly decreased, while that for the photoprocess also decreased. Both X-ray photoelectron spectroscopic studies and product analyses during the photoprocess clarified that photocatalytic oxidation of organic adsorbates in air causes the superhydrophilicity of the TiO(2) surfaces. Copyright 2000 Academic Press.

Neuroblastoma resection in an adult with a 10-year history of chest-mass shadow

Neuroblastoma is rare in adults. We encountered this tumor in an asymptomatic 21-year-old man with a 10-year history of a mass-like shadow in chest radiography. Diagnosis was confirmed after resection, and 60 Gy radiation therapy was started. One year later, the patient has no clinical or radiological evidence of recurrence.

Application of artificial dermis graft to correct a depression after tissue resection

The authors present 7 cases of artificial dermis implantation to correct a depression after tissue resection. Four of the seven cases resulted from resection of a malignant tumor (N = 3) and from a benign subcutaneous tumor (N = 1). The other 3 cases were the result of temporal muscle harvest to reconstruct facial palsy. In 1 patient a mild degree of bone deformity also existed. The pieces of artificial dermis employed varied from 35 x 40 to 40 x 80 mm in size. In 5 patients two sheets were implanted, and in 2 patients three sheets were implanted. In 2 patients the dermis sheets were covered by a pedicled temporal fascial flap with a free split-thickness skin graft because whole skin was resected as a result of a malignant skin tumor. There was no postoperative infection or allergic reaction in any of the patients. In all cases there was no postoperative contracture, and the implanted area was soft. An adequate or acceptable thickness of subcutaneous tissue was obtained. Artificial dermis may be a useful option as implantation material to correct a depression after tissue resection, especially for wide and comparatively shallow depressions.

[Thoracoscopic pleural biopsy under local anesthesia using a 2 mm laparoscope]

Thoracoscopy is indicated in patients with undiagnosed effusion after conventional methods. It has been usually performed under general anesthesia or using a thoracoscope with a thoracoscope with a diameter over 5 mm. However, it is an invasive diagnostic technique. We evaluated the feasibility of thoracoscopic pleural biopsy under local anesthesia using a 2 mm laparoscope. Six patients with a pleural effusion of unknown etiology after conventional methods, underwent thoracoscopy under local anesthesia. A 2 mm laparoscope and biopsy forceps (2 mm Minisite, United States Surgical Corp., USA) was used in all patients. Pleural fluid was removed, and the thoracic cavity was inspected. Thoracoscopic intercostal blocks were performed with 1% lidocaine, and then a biopsy was performed. The biopsy specimen was sent for histopathology. Three patients were shown to have carcinomatous pleurisy, two of them with localized lesions less than 10 mm. In the remaining three patients, non-specific diagnoses were made, but long-term follow-up revealed no malignant pleural disease. Although the pictures obtained using a 2 mm laparoscope were inferior in quality, they were adequate for the detection of malignant lesions in the pleural cavity. There were no procedure-related complications. These findings suggest that thoracoscopy using a 2 mm laparoscope is (1) a useful diagnostic tool in cases of pleural malignancy; (2) a minimally invasive method with the advantage of being easily performed under local anesthesia. Thus, thoracoscopic pleural biopsy using a 2 mm laparoscope appears to be useful for undiagnosed pleural effusion.

Cleavage of CD14 on human gingival fibroblasts cocultured with activated neutrophils is mediated by human leukocyte elastase resulting in down-regulation of lipopolysaccharide-induced IL-8 production

Activated polymorphonuclear leukocytes (PMNs) release various types of proteases and express them on the cell surface. The proteases play important roles in PMN-mediated events. In the present study, flow cytometric analysis revealed that CD14 expression on human gingival fibroblasts (HGF) was markedly reduced by PMA-activated PMNs in a coculture system. We found that this reduction was caused by both secreted and cell surface proteases produced by activated PMNs. A protease responsible for the reduction was found to be human leukocyte elastase (HLE) secreted from the activated PMNs by use of various protease inhibitors, although HLE was only partially involved in CD14 reduction caused by cell-bound molecule(s) on fixed PMNs. Analysis with purified HLE revealed a time- and dose-dependent reduction of CD14 on HGF, and complete reduction was observed by 20 microg/ml HLE treatment for 30-60 min, but the other molecules such as CD26, CD59, CD157, and MHC class I on HGF were only slightly reduced. This reduction of CD14 resulted from direct proteolysis by HLE on the cell surface, because HLE reduced CD14 on fixed HGF and also on purified cell membranes. As a result of CD14 proteolysis, IL-8 production by HGF was suppressed when triggered by 10 ng/ml LPS, but not by IL-1alpha, indicating that HLE inhibited a CD14-dependent cell activation. These findings suggested that activated PMNs have a potential negative feedback mechanism for HGF function at the inflammatory site, particularly in periodontal tissues.

[Psoas abscess caused by nephrolithiasis with perirenal abscess complicated with pleural effusion]

Left pleural effusion was found in a 60-year-old woman in whom chest radiography performed during a physical check up revealed no abnormality. Abdominal CT scanning revealed an abscess in the left psoas muscle. The psoas abscess was eliminated temporarily by drainage under ultrasonographic guidance and by the administration of antibiotics, but recurred one month later. A stag-horn renal stone considered to have caused the psoas abscess by formation of a perirenal abscess was eliminated by left nephrectomy. It is suggested tentatively that the psoas abscess might have been the cause of the pleural effusion.

Immunoliposome-mediated gene transfer into cultured myotubes

We encapsulated marker genes, pRSV-lacZ or pRSV-luc, in immunoliposomes conjugated with antibody targeting laminin B2 in the basal lamina of myotubes. The immunoliposomes were incubated with matured non-proliferating myotubes differentiated from C2C12 myoblasts. We then evaluated the efficiency of gene transfection by measuring luciferase activity and beta-galactosidase staining. The immunoliposomes conjugated with the antibody specific for myotubes were three times as efficient as control immunoliposomes conjugeted with an antibody not specific for myotubes. However, the efficiency was no more than that by the cationic liposomes without the antibody. These results suggest that laminin B2 is not effective in enhancing the efficiency of gene transfection for non-proliferating myotubes. A specific antibody for surface antigen other than laminin B2 should be chosen in further studies.

Malignant solitary fibrous tumor in the pleura

We present a case of malignant solitary fibrous tumor of the pleura in an asymptomatic 75-year-old man. A needle biopsy specimen revealed a solitary fibrous tumor of the pleura with suspected. The tumor was resected and the final diagnosis was a malignant solitary fibrous tumor. At one-and-a-half years later, the patient has no clinical or radiological evidence of recurrence. The propriety of a needle biopsy for preoperative diagnosis is discussed.

The fibronectin production is increased by thrombospondin via activation of TGF-beta in cultured human mesangial cells

Thrombospondin (TSP) is a multifunctional glycoprotein that is synthesized by a variety of cells including mesangial cells (MCs). To clarify the effect of TSP on the pathogenesis of diabetic nephropathy, we studied the effect of glucose concentrations on TSP synthesis in cultured human MCs. Thereafter, the effects of TSP on the activation of transforming growth factor beta (TGF-beta) and fibronectin production were investigated in MCs. Incubating MCs with elevated glucose levels for 6 days resulted in an increase in TSP synthesis, measured by an enzyme-linked immunosorbent assay, both in culture media and cell layers. Treatment of MCs with TSP (final concentrations 1 and 5 microg/ml) for 24 h resulted in an increase (1.3- and 2.1-fold, respectively) in active TGF-beta, which was determined with an enzyme-linked immunosorbent assay using TGF-beta-soluble receptor type II, in the culture media without having any effect on the production of total TGF-beta. Exposure of MCs to TSP caused enhancement of fibronectin production in both media and cell layers in a TSP dose-dependent manner with the maximum at a TSP concentration of 1 microg/ml. The TSP-induced increase in fibronectin production from MCs was completely prevented by concomitant treatment with 10 microg/ml anti-TGF-beta neutralizing antibody. These results indicate that the TSP production is promoted by a high ambient glucose concentration in human MCs and that TSP, in turn, causes an increase in fibronectin production via activation of TGF-beta.

Implantation of ultraflex nitinol stents in malignant tracheobronchial stenoses

STUDY OBJECTIVE

To assess the uncovered Ultraflex nitinol stent (Boston Scientific; Natick, MA) for its efficacy and safety.

DESIGN, SETTING, AND PATIENTS

Between October 1997 and October 1998, we carried out a prospective multicenter study at six hospitals in Japan. Fifty-four Ultraflex stents were inserted in 34 patients with inoperable malignant airway stenosis using a flexible and/or a rigid bronchoscope under fluoroscopic and endoscopic visualization.

MEASUREMENTS AND RESULTS

Clinical, endoscopic examination, and pulmonary function on days 1, 30, and 60 after stent implantation showed improvement. In 19 patients (56%), stent implantation was performed as an emergency procedure because of life-threatening tracheobronchial obstruction. Immediate relief of dyspnea was achieved in 82% of the patients. The dyspnea index improved significantly after implantation (before vs. days 1, 30, and 60; p<0.001). Significant improvements were observed in obstruction of airway diameter (81+/-15% before vs. 14+/-17% on day 1, 12+/-12% on day 30, and 22+/-28% on day 60; p<0.001). Vital capacity (VC), FEV(1), and peak expiratory flow (PEF) increased significantly after stent implantation: before vs immediately after VC (p<0.01), FEV(1) (p<0.001), and PEF (p<0.05). The main complications were tumor ingrowth (24%) and tumor overgrowth (21%). After coagulation with an Nd-YAG laser or argon plasma coagulation, mechanical coring out using the bevel of a rigid bronchoscope was necessary in patients showing tumor ingrowth or overgrowth. Removal and reposition were possible in case of misplacement. There were no problems with migration and retained secretions. The median survival time of patients was 3 months. The 1-year survival rate was 25.4%.

CONCLUSIONS

In this study of the Ultraflex nitinol stent, we have demonstrated that patients were relieved from dyspnea, which contributed to improved quality of life, with minimal complications. This stent can be used safely, even in the subglottic region. Owing to its excellent flexibility and biocompatibility, the stent is also indicated in certain complicated situations, eg, narrow stenosis, hourglass stenosis, curvilinear stenosis, bilateral mainstem bronchial stenoses, and long stenosis of varying diameters.

[Anatomical variations of Koch's triangle in patients with atrioventricular nodal reentrant tachycardia: usefulness of the left anterior oblique view]

OBJECTIVES

Several anatomical distances of Koch's triangle including the ablation site were measured and correlated with clinical features and slow pathway potentials in patients with atrioventricular nodal reentrant tachycardia to improve the avoidance of complete atrioventricular block.

METHODS

Sixty consecutive patients (24 males and 36 females, mean age 47 +/- 12 years) with successfully eliminated atrioventricular nodal reentrat tachycardia were studied. The distances between the His-bundle area and the base of the coronary sinus ostium (Dis HBE-CS) and the distances between the successful ablation site and the base of the CS ostium (Dis SP-CS) were measured in both right anterior oblique and left anterior oblique views, and used to define the dimensions of Koch's triangle. The relationship between the slow pathway potentials at the successful ablation site and anatomical distances was estimated.

RESULTS

The Dis HBE-CS in the right anterior oblique view was negatively correlated with patient age (r = -0.759, p < 0.001) and body mass index. In contrast, the Dis HBE-CS in the left anterior oblique view had only weak correlations with patient age and body mass index. The mechanism of the short Dis HBE-CS in the right anterior oblique view in elderly obese patients tended to change the shape of the tricuspid annulus from a circle to an ellipse, compressed by the ascending aorta and diaphragma. The Dis SP-CS in the right anterior oblique view associated with the low frequency potential (Haissaguerre's slow pathway potential) was longer than that associated with the high frequency potential (Jackman's slow pathway potential).

CONCLUSIONS

Elderly obese patients had shorter distances between the proximal His-bundle area and the base of the coronary sinus ostium in the right anterior oblique view. In contrast, the Dis HBE-CS in the left anterior oblique view was not so narrow. Therefore, slow pathway ablation can be performed safely without complicated complete atrioventricular block, using both the slow pathway potential guided approach and the anatomical guided approach, especially in the left anterior oblique view.

Changes in cytokine production during and after normal pregnancy

PROBLEM

The systemic T helper 1/T helper 2 (Th1/Th2) cytokine balance during normal human pregnancy is controversial, and observations about the balance in the postpartum period have only been reported for up to 3 months.

METHOD

Whole-blood, from 83 healthy pregnant women, 80 healthy postpartum women, and 31 healthy non-pregnant women was stimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin, and the levels of cytokines in the supernatant were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The production of all measured cytokines decreased during pregnancy, especially in the second trimester. After delivery, interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) increased from 2 to 11 months postpartum, and IL-4 increased from 6 to 11 months postpartum.

CONCLUSIONS

These data indicate that 1) decreases in production of both Th1-and Th2-type cytokines during pregnancy may be related to the pregnancy-induced amelioration of autoimmune diseases: 2) increases in production of both Th1- and Th2-type cytokines in the postpartum period may be related to the postpartum aggravation of autoimmune diseases.

Demonstration of diastolic and presystolic Purkinje potentials as critical potentials in a macroreentry circuit of verapamil-sensitive idiopathic left ventricular tachycardia

OBJECTIVES

The purpose of this study was to determine the relation of diastolic and presystolic potentials recorded during verapamil-sensitive idiopathic left ventricular tachycardia (ILVT) to reentry circuit.

BACKGROUND

Successful ablation of verapamil-sensitive ILVT at the zone of slow conduction from which the diastolic potential is recorded has been reported. However, the relationship between the diastolic potential and the reentrant circuit remains a matter of debate.

METHODS

Radiofrequency (RF) ablation was performed in 20 patients with verapamil-sensitive ILVT. After identifying the ventricular tachycardia (VT) exit site, we searched for the mid-diastolic potential (P1) during VT. Entrainment followed by RF current application was performed. If the mid-diastolic potential could not be detected, RF current was applied at the VT exit site showing the earliest ventricular activation with a single fused presystolic Purkinje potential (P2).

RESULTS

In 15 of 20 patients, both P1 and P2 were recorded during VT from midseptal region. Entrainment pacing captured P1 orthodromically and reset the VT. The interval from stimulus to P1 was prolonged as the pacing rate was increased. Radiofrequency ablation was successfully performed at this site in all 15 patients. After successful ablation, P1 appeared after the QRS complex during sinus rhythm with the identical sequence to that during VT. In the remaining five patients, the diastolic potential could not be detected, and a single fused P2 was recorded only at the VT exit site. Successful ablation was performed at this site in all five patients.

CONCLUSIONS

This study demonstrates that P1 and P2 are critical potentials in a circuit of verapamil-sensitive ILVT and suggests the presence of a macroreentry circuit involving the normal Purkinje system and the abnormal Purkinje tissue with decremental property and verapamil-sensitivity.

Enzyme-linked immunosorbent assay for anti-tropomyosin antibodies and its clinical application to various heart diseases

Tropomyosin is one of the key proteins for muscle contraction. We developed an enzyme-linked immunosorbent assay for antibodies to porcine muscle tropomyosin and measured serum anti-tropomyosin antibodies in patients with heart diseases and in normal controls. The mean values of absorbance in the ELISA assay of patients with ischemic heart disease (n=36, P<0.001), dilated cardiomyopathy (n=28, P<0.005), valvular heart disease (n=27, P<0.05), and collagen disease (n=38, P<0.05) were significantly higher than those of normal controls (n=53), but the value in patients with hypertrophic cardiomyopathy (n=19) was not significantly different from that of normal controls. When the cut-off value was fixed at the mean+2 SD of absorbance in normal controls, positive reactions were found in 19.4%, 7.1%, 18.5% and 15.8% of patients with ischemic heart disease, dilated cardiomyopathy, valvular heart disease, and collagen disease, respectively. An inhibition study revealed that anti-tropomyosin antibodies were different from anti-myosin antibodies, but there was a partial cross-reactivity between the two. Thus, there was a weak correlation of the titers of the two types of antibody within the group of heart diseases. These data indicate that measurement of anti-tropomyosin antibodies by ELISA is helpful for detecting autoimmune abnormalities in various heart diseases.

Coronary vascular K+ATP channels contribute to the maintenance of myocardial perfusion in dogs with pacing-induced heart failure

The functional role of coronary vascular ATP-sensitive potassium (K+ATP) channels in the regulation of coronary blood flow (CBF) has not been determined in chronic heart failure (CHF). To test the hypothesis that K+ATP channels contribute to myocardial perfusion in HF, we examined the effects of intracoronary infusion of glibenclamide, an inhibitor of K+ATP channels, on basal CBF in control and CHF dogs. CHF was produced in mongrel dogs by pacing the right ventricle for 4 weeks. Under anesthesia, CBF in the left anterior descending coronary artery, other hemodynamic and metabolic parameters, or regional myocardial blood flow were measured. Basal CBF was less in CHF dogs than in controls. Glibenclamide at the graded doses (5, 15 and 50 microg x kg(-1) x min(-1) decreased CBF in both control and CHF dogs. The percentage decrease in CBF with glibenclamide at 50 microg x kg(-1) x min(-1) was greater (p<0.01) in CHF dogs than in controls. The greater decrease in CBF with glibenclamide at 50microg x kg(-1) x min(-1) was associated with myocardial ischemia. Glibenclamide decreased myocardial blood flow in each sublayer of the myocardium in the 2 groups. These results suggest that the basal activity of coronary vascular K+ATP channels is increased in CHF dogs but not in controls. This may contribute to the maintenance of myocardial perfusion in CHF.

Stabilization of human RNase 1 by introduction of a disulfide bond between residues 4 and 118

In order to stabilize human RNase 1 by introduction of an intramolecular cross-link, a mutant protein (4-118CL RNase 1), in which Arg4 and Val118 are replaced with cysteine residues and linked by a disulfide bond, was designed and expressed in Escherichia coli as inclusion bodies. The 4-118CL RNase 1 that refolded under redox conditions was a monomer without free SH groups and retained 11% of the activity of the wild-type recombinant RNase 1, indicating that the mutant enzyme was correctly folded with the formation of an additional disulfide bond between Cys4 and Cys118. From guanidium chloride denaturation experiments based on the assumption of a two-state transition for unfolding, it was demonstrated that the introduction of the present cross-link increased the thermodynamic stability of RNase 1 by 2.0 kcal/mol. This value was lower than that, 5.4 kcal/mol, theoretically calculated from the reduction of chain entropy of the unfolded state due to the introduction of the cross-link. These results suggest that the present cross-link also destabilized the folded state of RNase 1 by 3.4 kcal/mol. Along with the increase in the thermodynamic stability, the stability of RNase 1 against trypsin digestion was also significantly increased by the introduction of this cross-link. It is likely, although not proven, that stabilized human RNases are favorable for clinical use, because human RNase-based immunotoxins should have long half-lives as to proteolytic degradation after endocytosis.

Three-dimensional crystal structure of human eosinophil cationic protein (RNase 3) at 1.75 A resolution

Eosinophil cationic protein (ECP; RNase 3) is a human ribonuclease found only in eosinophil leukocytes that belongs to the RNase A superfamily. This enzyme is bactericidal, helminthotoxic and cytotoxic to mammalian cells and tissues. The protein has been cloned, heterologously overexpressed, purified and crystallized. Its crystal structure has been determined and refined using data up to 1. 75 A resolution. The molecule displays the alpha+beta folding topology typical for members of the ribonuclease A superfamily. The catalytic active site residues are conserved with respect to other ribonucleases of the superfamily but some differences appear at substrate recognition subsites, which may account, in part, for the low catalytic activity. Most strikingly, 19 surface-located arginine residues confer a strong basic character to the protein. The high concentration of positive charges and the particular orientation of the side-chains of these residues may also be related to the low activity of ECP as a ribonuclease and provides an explanation for its unique cytotoxic role through cell membrane disruption.

Effect of epinephrine and combination treatment of epinephrine and heat on melanoma cell lines. Study of cytotoxicity and kinetics of 72-kD stress protein

To elucidate the effect of epinephrine and the combination with heat on malignant cells, using two melanoma cell lines, HM6KO and G361, we have examined the cytotoxicity and induction of 72-kD stress protein (HSP72) after the treatments. After epinephrine treatment, in both cell lines, cell survival rates decreased gradually in a concentration-dependent manner. After the combination treatment, cell survival rates decreased more than those when two treatments were done separately. The cytotoxicity of epinephrine was more enhanced in G361 than in HM6KO by heat. After epinephrine treatment, in both cell lines, the level of HSP72 did not elevate. After combination treatment, in HM6KO, the level of HSP72 were higher than those of heat alone. In G361, the kinetics of HSP72 level was similar to that of heat alone. These results suggest that epinephrine has a cytotoxicity to melanoma cells and the cytotoxicity is enhanced by the combination. In addition, it is probable that epinephrine does not have HSP72 inducibility in HM6KO and G361, and the different kinetics of HSP72 between the cell lines in the combination treatment may play an important role to determine the degree of enhancement.

Proteolysis of human monocyte CD14 by cysteine proteinases (gingipains) from Porphyromonas gingivalis leading to lipopolysaccharide hyporesponsiveness

Cysteine proteinases (gingipains) elaborated from Porphyromonas gingivalis exhibit enzymatic activities against a broad range of host proteins and are considered key virulence factors in the onset and development of adult periodontitis and host defense evasion. In this study, we examined the ability of arginine-specific gingipains (high molecular mass Arg-specific gingipain (HRGP) and Arg-specific gingipain 2) and lysine-specific gingipain (KGP) to cleave monocyte CD14, the main receptor for bacterial cell surface components such as LPS. Binding of anti-CD14 mAb MY4 to human monocytes was almost completely abolished by 0.3 microM HRGP and KGP treatments for 15 min, and 1 microM RGP2 for 30 min. In contrast, the expressions of Toll-like receptor 4, and CD18, CD54, CD59, and HLA-A, -B, -C on monocytes were slightly increased and decreased, respectively, by 0. 3 microM HRGP and KGP. This down-regulation resulted from direct proteolysis, because 1) gingipains eliminated MY4 binding even to fixed monocytes, and 2) CD14 fragments were detected in the extracellular medium by immunoblot analysis. Human rCD14 was degraded by all three gingipains, which confirmed that CD14 was a substrate for gingipains. TNF-alpha production by monocytes after HRGP and KGP treatments was decreased at 1 ng/ml, but not at 20 microg/ml LPS, indicating that gingipains inhibited a CD14-dependent cell activation. These results suggest that gingipains preferentially cleave monocyte CD14, resulting in attenuation of the cellular recognition of bacteria, and as a consequence sustain chronic inflammation.

[Depression of serum pyridoxal levels in theophylline-related seizures]

In order to study whether a theophylline-related seizure is caused by a decrease in serum vitamin B6, serum pyridoxal (PAL) levels were measured in children with bronchial asthma treated with theophylline. The serum PAL levels of asthmatic children (n = 31) treated with theophylline were significantly lower than those of control subjects (n = 21). Moreover, we evaluated PAL levels in four subjects within twenty-four hours after a seizure with or without fever. The level was low in three of the four. These results suggest that the decrease in PAL levels caused by theophylline may lower the seizure threshold.

Molecular cloning and expression of rat betacellulin cDNA

The cDNA encoding an entire open reading frame of rat betacellulin has been cloned from rat kidney. Expression of this cDNA in COS7 cells showed a significant amount of mitogenic activity in the culture media. Western blotting of the cell lysates suggested that the membrane-anchored precursor was cleaved to release its ectodomain very efficiently.

Preoperative diagnosis of thyroid carcinomas by aspiration biopsy-reverse transcription-polymerase chain reaction (ABRP): a report of two cases

A preoperative molecular-based diagnostic technique for thyroid papillary and anaplastic carcinomas was recently developed to detect oncofetal fibronectin (onfFN) messenger RNA (mRNA) in fine needle aspiration biopsy (FNAB) by means of reverse transcription-polymerase chain reaction (RT-PCR). We report two cases of thyroid tumors, in which cytological diagnosis was not successful but in which RT-PCR analysis provided information that helped to identify the biological features of the tumors. One case could not be diagnosed by aspiration biopsy cytology (ABC) because of poor fixation; however, RT-PCR did detect the expression of onfFN mRNA, which suggested the existence of papillary carcinoma cells. After surgery, this tumor was diagnosed as a papillary carcinoma by histological examination. The other case was diagnosed as a papillary carcinoma by ABC, but onfFN mRNA was not detected in the FNAB by RT-PCR. The neoplasm was diagnosed as a follicular tumor by histological examination. These cases suggest the benefits of combining both genetic and cytological approaches to the examination of FNAB.

CD13/aminopeptidase N, a novel chemoattractant for T lymphocytes in pulmonary sarcoidosis

CD13/aminopeptidase N (E.C.3.4.11.2) is an ectoenzyme located in the outer membrane of a variety of cells. Because aminopeptidase expression was shown to be upregulated by a Th1-related cytokine, IFN-gamma, we examined here the significance of CD13/aminopeptidase N in pulmonary sarcoidosis. The activity of aminopeptidase in bronchoalveolar lavage fluid (BALF) was significantly higher in patients with sarcoidosis than in normal volunteers (NV) and control patients (CP). The activity significantly correlated with lymphocyte percentages and the ratio of CD4+ to CD8+ T lymphocytes in the BALF, and was higher in patients with sarcoidosis with parenchymal involvement than in those without the involvement. CD13/aminopeptidase N protein, which has a molecular mass of approximately 150 kD, was detectable in alveolar macrophages (AM) from patients with sarcoidosis at higher levels than in those from NV. CD13/aminopeptidase N induced in vitro chemotactic migration of human lymphocytes in a concentration range of 10(-)(5) to 10(-)(1) U/ml. The chemotactic activity was greater for CD4+ T lymphocytes than for CD8+ T lymphocytes. The enzymatic activity of CD13/aminopeptidase N was responsible for the chemotactic activity because bestatin, an inhibitor of CD13/aminopeptidase N, abolished the chemotactic activity. Higher chemotactic activity for lymphocytes was detected in the BALF from patients with sarcoidosis than in that from NV, and the activity was significantly decreased by treatment with bestatin. This study indicates that CD13/ aminopeptidase N expressed in AM may have a role in T-lymphocyte involvement in the sarcoid lung and the pathogenesis of alveolitis in this disorder.

An evaluation of hard palate mucosa graft as a lining material in alar reconstruction: a 7-year experience applied to the full-thickness alar defect

The authors present their experience with 25 hard palate mucosa grafts used as lining material in the reconstruction of full-thickness alar defects. Good "take" was obtained in 22 grafts; the other three grafts incurred necrosis of the overriding skin flaps and postoperative infection. Degree of shrinkage was 11 to 15 percent of grafted size in patients with the type of defect that did not include the alar margin; shrinkage was 26 to 35 percent in patients with the type that included more than 50 percent of the alar margin. In all patients who had a good graft take, the nasal cavities were maintained and there was no nasal obstruction or collapsing during strong breathing. The healing time of the palate donor site varied from 7 days to 5 weeks, depending on the size of the defect. No patients experienced any symptoms at the donor site after healing. The authors concluded that hard palate mucosa can be considered a useful material in alar reconstruction because of the ease in graft harvesting and its support features. When the defect is large enough to involve the total unilateral ala nasi, even though the degree of postoperative shrinkage is comparatively high, hard palate mucosa may be the most suitable material to ensure good take of the graft and less possibility of donor-site morbidity.

Effects of preoperative chemotherapy and radiation therapy on human bronchial blood flow

OBJECTIVE

We investigated the relationship between bronchial mucosal blood flow around the area of lung resection and the state of healing of the bronchial stump in patients after chemotherapy with or without radiation therapy.

METHODS

Ninety patients with primary lung cancer were divided into the following 3 groups: group A, 72 patients who had no preoperative therapy; group B, 10 patients who had chemotherapy; and group C, 8 patients who had chemoradiation (60 Gy) therapy. Bronchial mucosal blood flow was measured preoperatively, intraoperatively, and postoperatively (days 8-10) with a laser Doppler flowmeter.

RESULTS

In groups A and B bronchial mucosal blood flow was preserved sufficiently around the surgical site, and the healing of the bronchial stump was satisfactory. On the contrary, preoperative blood flow in group C was 70% of the preoperative value in group A and decreased further intraoperatively. Healing of the bronchial stump was poor, and a bronchopleural fistula occurred in one patient of group C.

CONCLUSION

Preoperative chemoradiation therapy may adversely affect bronchial mucosal blood flow and healing of the bronchial stump, although lymphadenectomy and preoperative chemotherapy had little effect. It is recommended that the bronchial stump should be covered with pedicled viable tissue after chemoradiation therapy for prophylaxis against bronchial complications.

[Significance of exercise-induced ST segment depression in patients with myocardial infarction involving the left circumflex artery: evaluation by exercise thallium-201 myocardial single photon emission computed tomography]

The significance of exercise-induced ST segment depression in patients with left circumflex artery involvement was investigated by comparing exercise electrocardiography with exercise thallium-201 single photon emission computed tomography(Tl-SPECT) and the wall motion estimated by left ventriculography. Tl-SPECT and exercise electrocardiography were simultaneously performed in 51 patients with left circumflex artery involvement(angina pectoris 30, myocardial infarction 21). In patients with myocardial infarction, exercise-induced ST depression was frequently found in the V2, V3 and V4 leads. In patients with angina pectoris, ST depression was frequently found in the II, III, aVF, V5 and V6 leads. There was no obvious difference in the leads of ST depression in patients with myocardial infarction with ischemia and without ischemia on Tl-SPECT images. In patients with myocardial infarction, the lateral wall motion of the infarcted area evaluated by left ventriculography was more significantly impaired in the patients with ST depression than without ST depression(p < 0.01). Exercise-induced ST depression in the precordial leads possibly reflects wall motion abnormality rather than ischemia in the lateral infarcted myocardium.

Cobalt Ion-Doped TiO(2) Photocatalyst Response to Visible Light

Photocatalytic activity under visible light irradiation was generated by doping a small amount of Co(2+) ions into TiO(2) particles. Nanometer-sized particles with the composition xCoO-(100-x) TiO(2) (xCo/TiO(2); 0</=x</=6.0) were prepared from TiOSO(4).4.5H(2)O and Co(CH(3)COO)(2).4H(2)O in an ethanol-water solution containing NaOH under reflux. The photoreactivity of xCo/TiO(2) was evaluated by the rate of CH(3)CHO degradation. The Co(2+) ion doping (0.01</=x</=0.27) not only enhanced the photocatalytic activity under ultraviolet-visible (lambda>300 nm) light irradiation but also induced the visible light (lambda>400 nm) response. The highest photocatalytic activities were obtained at x=0.03 for both irradiations. Copyright 2000 Academic Press.

Serum dehydroepiandrosterone, dehydroepiandrosterone sulfate, and pregnenolone sulfate concentrations in patients with hyperthyroidism and hypothyroidism

BACKGROUND

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) have been suggested to have protective effects against cardiovascular disease, cancer, immune-modulated diseases, and aging. We examined serum concentrations of DHEA, DHEA-S, and pregnenolone sulfate (PREG-S) in patients with thyroid dysfunction.

METHODS

Steroids extracted with methanol from serum sample were separated into an unconjugated fraction (DHEA) and a monosulfate fraction (DHEA-S and PREG-S), using a solid-phase extraction and an ion-exchange column. After separation of unconjugated steroids by HPLC, the DHEA concentration was measured by enzyme immunoassay. The monosulfate fraction was treated with arylsulfatase, and the freed steroids were separated by HPLC. The DHEA and PREG fractions were determined by gas chromatography-mass spectrometry, and the concentrations were converted into those of DHEA-S and PREG-S.

RESULTS

Serum concentrations of DHEA, DHEA-S, and PREG-S were all significantly lower in patients with hypothyroidism (n = 24) than in age- and sex-matched healthy controls (n = 43). By contrast, in patients with hyperthyroidism (n = 22), serum DHEA-S and PREG-S concentrations were significantly higher, but the serum DHEA concentration was within the reference interval. Serum concentrations of these three steroids correlated with serum concentrations of thyroid hormones in these patients. Serum albumin and sex hormone-binding globulin concentrations were not related to these changes in the concentration of steroids.

CONCLUSIONS

Serum concentrations of DHEA, DHEA-S, and PREG-S were decreased in hypothyroidism, whereas serum DHEA-S and PREG-S concentrations were increased but DHEA was normal in hyperthyroidism. Thyroid hormone may stimulate the synthesis of these steroids, and DHEA sulfotransferase might be increased in hyperthyroidism.

Convenient and efficient in vitro folding of disulfide-containing globular protein from crude bacterial inclusion bodies

We investigated how the folding yield of disulfide-containing globular proteins having positive net charges from crude bacterial inclusion bodies was affected by additives in the folding buffer. In screening folding conditions for human ribonucleases and its derivative, we found that addition of salt (about 0.4 M) to a folding buffer increased the folding yield. This suggested that electrostatic interaction between polyanionic impurities such as nucleic acids and cationic unfolded protein led to the formation of aggregates under the low-salt conditions. Since inclusion bodies were found to contain nucleic acids regardless of the electrostatic nature of the expressed protein, the electrostatic interaction between phosphate moieties of nucleic acids and basic amino acid residues of a denatured protein may be large enough to cause aggregation, and therefore the addition of salt in a folding buffer may generally be useful for promotion of protein folding from crude inclusion bodies. We further systematically investigated additives such as glycerol, guanidium chloride, and urea that are known to act as chemical chaperons, and found that these additives, together with salt, synergistically improved folding yield. This study, suggesting that the addition of salt into the folding buffer is one of the crucial points to be considered, may pave the way for a systematic investigation of the folding conditions of disulfide-containing foreign proteins from crude bacterial inclusion bodies.

Detection of measles virus genome in bronchoalveolar lavage cells in a patient with measles pneumonia

Measles is frequently complicated with pneumonia that could be fatal in numerous occasions. However, a prompt and precise diagnosis of measles is not easily made particularly in the early stage of the disease, or in immunocompromised individuals because of the lack of typical clinical features or the defect in antigen-specific antibody production. In the present paper, we describe a 27-yr-old male who developed fever, skin rash typical of measles, and diffuse pulmonary infiltrates associated with respiratory failure. Infection of lung cells with measles virus was proved by detection of viral genome ribonucleic acid within alveolar macrophages and lymphocytes recovered by bronchoalveolar lavage using reverse transcription-polymerase chain reaction amplification. These techniques may offer a useful tool to make the swift and precise diagnosis of measles pneumonia, thus allowing appropriate therapeutic approaches to the disease.

ST segment and T wave alternans in a patient with Brugada syndrome

We describe a patient with Brugada syndrome in whom J point and ST-segment elevation in leads V1 and V2 were augmented by atrial pacing and intravenous administration of propranolol or cibenzoline. Significant T wave alternans with a 2:1 appearance of terminal negative T wave was observed in the absence and presence of atrial pacing after the administration of cibenzoline. The cellular mechanism responsible for T wave alternans, beat-to-beat appearance of terminal negative T wave and augmented J point and ST-segment elevation is discussed.