Altered expression of dermokine in skin disorders

BACKGROUND

Although dermokine-β, a glycoprotein expressed in epithelial cells, does not have significant homology to other proteins, its carboxyl-terminal domain shares a high pI value with many cytokines, suggesting similar functions.

OBJECTIVE

To better understand the biology of dermokine, we here determined its localization under pathological conditions and examined factors that regulate its expression.

METHODS

We generated an anti-human dermokine-β/γ monoclonal antibody cross-reacting with the mouse protein. Using this antibody, immunohistological staining and Western blotting of dermokine-β/γ were performed with various tissue samples.

RESULTS

Although human dermokine-β/γ was expressed in almost all granular layers, upper spinous layers of the skin were also stained with anti-dermokine-β/γ antibody in inflammatory skin disorders. Dermokine-β/γ was expressed in keratoacanthoma and a part of well-differentiated squamous cell carcinoma (SCC). However, dermokine-β/γ was not detected in poorly differentiated SCC or tumours derived from non-keratinocytes. In mice, dermokine-β/γ-expressed keratinocytes were increased in models of contact hypersensitivity, ultraviolet-irradiated skin injury and wound healing. Consistent with expanded distribution in inflammatory skin diseases, proinflammatory cytokines such as interleukin-1β, interleukin-12, and tumour necrosis factor-α augmented dermokine-β/γ expression in cultured human keratinocytes. In contrast, growth factors including epidermal growth factor, insulin-like growth factor-I, keratinocyte growth factor and transforming growth factor-α significantly reduced dermokine expression.

CONCLUSION

These results provide novel insights into the physiological and pathological significance of dermokine in the epidermis.

Blood cardioplegia serves as a bicarbonate donor to the myocardium during ischemia: effects of anoxia and hypercapnia on acid-base characteristics of blood cardioplegic solution

OBJECTIVES

We investigated the alterations of acid-base characteristics of the blood cardioplegia (BCP) solution during aortic cross-clamping in hearts arrested with BCP and during in vitro-simulated ischemia.

METHODS

Following aortic cross-clamping, the hearts of 40 patients undergoing cardiac surgery were intermittently infused with an 18°C BCP solution and finally with a 34°C BCP solution prior to aortic cross-clamp release. We measured the pH, partial CO(2) pressure (pCO(2)), [HCO(3)(-)], and [Cl(-)] of the coronary sinus effluent in the final BCP solution. The BCP solution was assessed under in vitro gassing at 34°C with 95% N(2) + 5% CO(2) (n = 6), 50% N(2) + 50% CO(2) (n = 3), or 100% CO(2) (n = 6).

RESULTS

The coronary sinus effluent, compared with the preinfusion BCP solution, exhibited a significantly lower pH and a greater pCO(2) with no change in the [HCO(3)(-)] level. In vitro, the 95% N(2) + 5% CO(2) gassing (simulated hypoxia) group exhibited a slight increase in [HCO(3)(-)] with no change in pCO(2) or pH whereas the 50% N(2) + 50% CO(2) gassing and the 100% CO(2) gassing (simulated hypoxia and hypercapnia) groups exhibited a significant increase in [HCO(3)(-)] under high pCO(2)-induced acidification.

CONCLUSIONS

Under anoxia and CO(2) retention during aortic cross-clamping, the BCP solution can be a bicarbonate donor to the myocardium.

Degradation of filamin induces contraction of vascular smooth muscle cells in type-I collagen matrix honeycombs

BACKGROUND

Dedifferentiated rabbit vascular smooth muscle cells (SMCs) exhibit similar features to differentiated SMCs when cultured in three-dimensional matrices of type-I collagen called "honeycombs," but the mechanism is unknown. The role of filamin, an actin-binding protein that links actin filaments in SMCs, was investigated.

METHODS

Filamin and other related proteins were detected by western blot analysis and immunofluorescence staining. Honeycomb size was measured to confirm the contraction of SMCs.

RESULTS

Full-length filamin was expressed in subconfluent SMCs cultured on plates; however, degradation of filamin, which might be regulated by calpain, was observed in confluent SMCs cultured on plates and in honeycombs. While filamin was co-localized with β-actin in subconfluent SMCs grown on plates, filamin was detected in the cytoplasm in SMCs cultured in honeycombs, and degraded filamin was mainly detected in the cytoplasmic fraction of these cells. In addition, β-actin expression was low in the cytoskeletal fraction of SMCs cultured in honeycombs compared with cells cultured on plates, and the size of the honeycombs used for culturing SMCs was significantly reduced.

CONCLUSION

These data suggest that degradation of filamin in SMCs cultured in honeycombs induces structural weakness of β-non-muscle actin filaments, thereby permitting SMCs in honeycombs to achieve contractility.

[Surgical repair of extracardiac unruptured aneurysm of the sinus of Valsalva]

An isolated extracardiac unruptured aneurysm of the non-coronary sinus of Valsalva was detected incidentally in a 49-year-old woman with chronic obstructive pulmonary disease. The orifice of the aneurysm was closed with XAG-400 patch. The aortic valve was normal. 20 cases of successful operation have been reported in Japan with extracardiac unruptured aneurysm. In the review of the literature, patch closure of the orifice of the aneurysm was the standard procedure in most cases. However, aortic root replacement was required in some cases with concomitant cardiac and/or aortic disease.

[Management of mediastinitis and preventions of perioperative nosocomial infection after cardiovascular surgery]

This article reviews risk factors and treatment of perioperative nosocomial infections. The primary prophylactic antibiotic is recommended to be a cefazolin or penicillin with sulbactam, because the most frequent organism cultured in cardiac surgical site infection (SSI) is Staphyloccocus. Antibiotic prophylaxis of 48 hours' duration after cardiovascular surgery is clinically effective in minimizing infectious complication. In patients considered at high risk for a staphylococcal infection, vancomycin may be recommended. In the treatment of postoperative infections, Gram-stain-based antibiotic selection is necessary and the initial empirical therapy to ensure adequate coverage of potentially infective organisms should be accompanied by de-escalation until microbiological data become available. Mediastinitis, which is one of the important infectious complications after cardiovascular surgery, requires surgical drainage and debridement, as well as antimicrobial therapy. Vacuum-assisted closure (VAC) is an effective therapy compared with the conventional technique of open packing. Continuous clinician's efforts and prolonged infection control programs are very important for prevention of perioperative nosocomial infection after cardiac surgery.

[Chemotherapy for cervical carcinoma]

Although cisplatin-based chemotherapy is standard regime for cervical cancer, the major question remains as to what kind of drug is the best candidate for combination with cisplatin. According to recent reports, platinum+taxane is supposed to be a promising combination for not only squamous cell carcinoma but also adenocarcinoma of cervix. Studies of neoadjuvant chemotherapy followed by radiotherapy demonstrate no advantage for overall survival of locally advanced cervical carcinoma. Otherwise, neoadjuvant chemotherapy followed by radical surgery was confirmed to offer a survival advantage in a few prospective randomized trials but its statistical power was low due to small number of patient cases. The platinum+taxane combination is good and its effects should be evaluated on overall survival in the same modality. Concurrent radiotherapy with weekly cisplatin is standard therapy for primary and adjuvant setting for squamous cell carcinoma and adenocarcinoma of cervix.

A DNA microarray-based methylation-sensitive (MS)-AFLP hybridization method for genetic and epigenetic analyses

We previously developed a PCR-based DNA fingerprinting technique named the Methylation Sensitive (MS)-AFLP method, which permits comparative genome-wide scanning of methylation status with a manageable number of fingerprinting experiments. The technique uses the methylation sensitive restriction enzyme NotI in the context of the existing Amplified Fragment Length Polymorphism (AFLP) method. Here we report the successful conversion of this gel electrophoresis-based DNA fingerprinting technique into a DNA microarray hybridization technique (DNA Microarray MS-AFLP). By performing a total of 30 (15 x 2 reciprocal labeling) DNA Microarray MS-AFLP hybridization experiments on genomic DNA from two breast and three prostate cancer cell lines in all pairwise combinations, and Southern hybridization experiments using more than 100 different probes, we have demonstrated that the DNA Microarray MS-AFLP is a reliable method for genetic and epigenetic analyses. No statistically significant differences were observed in the number of differences between the breast-prostate hybridization experiments and the breast-breast or prostate-prostate comparisons.

Tei index determined by tissue Doppler imaging in patients with pulmonary regurgitation after repair of tetralogy of Fallot

The myocardial performance index (Tei index) determined by the pulsed Doppler method is a simple and noninvasive measurement for assessing global right ventricular (RV) function. This index can also be obtained by tissue Doppler imaging (TDI). The effects of significant pulmonary regurgitation (PR) on the determination of the Tei index by these two methods have not been investigated. We examined 15 patients (6.3 +/- 2.2 years) with significant PR after repair of tetralogy of Fallot (TOF) and 24 age-matched healthy children. Myocardial wall motion velocities at the tricuspid annulus were assessed during systole (Sa), early diastole (Ea), and late diastole (Aa) from a four-chamber view. Pulsed Doppler-Tei index and TDI-Tei index were measured as reported previously. The Tei index obtained by the pulsed Doppler method in TOF patients did not differ from that in normal children (0.30 +/- 0. 12 vs 0.32 +/- 0.07, p = not significant). TDI showed that TOF patients had significantly decreased Ea, Aa, and Sa velocities compared to those of normal children. Both isovolumic contraction time and isovolumic relaxation time in TOF patients were significantly longer than those in normal children (88 +/- 18 vs 62 +/- 23 msec and 46 +/- 11 vs 21 +/- 12 msec, respectively; p < 0.0001), although the duration of Sa did not differ between the two groups. Consequently, the Tei index as measured by TDI was significantly greater in TOF patients than in normal children (0.48 +/- 0.07 vs 0.30 +/- 0.07, p < 0.0001). The Tei index measured by the pulsed Doppler method is limited in its ability to assess RV function in patients with significant PR. However, the Tei index determined by TDI is a sensitive indicator of RV function in these patients, and it appears to be a promising new means of assessing global RV function in patients with significant PR.

Concentration of clarithromycin and 14-R-hydroxy-clarithromycin in plasma of patients with Mycobacterium avium complex infection, before and after the addition of rifampicin

Clarithromycin (CAM) and rifampicin (RFP) have both been recognized to be effective antibiotic agents against Mycobacterium avium complex (MAC) infection. Rifamycin derivatives including RFP and rifabutin modulate the CAM metabolism by inducing the hepatic cytochrome p-450 3A4. To clarify the effect of RFP on the CAM metabolism, we measured the plasma concentration of CAM and 14-R-hydroxyclarithromycin (M-5), the major metabolite of CAM, in 9 patients suffering from MAC infection before and after the addition of RFP. After the addition of RFP, the mean plasma concentration of CAM significantly decreased, while that of M-5 did not. In addition, the amount of CAM + M-5 concentration also significantly decreased. As M-5 is less effective against MAC infection than CAM, more attention should thus be paid to the plasma CAM concentration in patients administered CAM and RFP concomitantly.

Polymorphisms in the interleukin-4 receptor alpha chain: association with traits of allergy and asthma in an admixed population in Hawaii

Single nucleotide polymorphisms (SNPs) in the gene encoding the interleukin-4 receptor alpha chain (IL-4R alpha) have been associated with IgE levels or clinical atopy in some populations. Two SNPs that encode S503P and Q576R in the intracytoplasmic domain of the receptor are associated with loss or gain of function, respectively. We investigated the frequency of these SNPs and their association with traits of allergic asthma in 36 unrelated subjects selected from a racially admixed, clinically ascertained study population with family histories of asthma. The frequency of the 1682 T to C substitution that encodes S503P was 0.11 (70 alleles analyzed, from 29 TT homozygotes and 6 TC heterozygotes). The frequency of the 1902 A to G substitution that encodes Q576R was 0.26 (68 alleles analyzed, from 20 AA homozygotes, 10 AG heterozygotes and 4 GG homozygotes). In this atopic admixed sample, no significant association was detected between the variant genotypes and serum IgE levels, percentage of eosinophils, skin test reactivity, diagnosis of asthma or methacholine reactivity. More conclusive findings await clinical characterization of non-atopic, non-asthmatic subjects as well as more efficient and extensive haplotyping.

A base substitution in the interleukin-10 (IL-10) promoter between Sp1 and ets-1 binding sites is not associated with variation of IL-10 levels

Interleukin 10 (IL-10) may play an important anti-inflammatory and immunoregulatory role in asthma. In this study, we investigated the role of a C to A substitution at position -627 of the IL-10 promoter, located in a necessary transcriptional region, which contains a number of putative transcriptional binding sites. The -627 nucleotide position is itself flanked by Sp-1 and ets-1 binding sites. We studied the allele frequency in 53 unrelated subjects from an admixed Caucasian, Asian and Pacific Islander group with personal or family histories of asthma. The frequency of homozygous C/C, heterozygous C/A, and homozygous A/A alleles at position -627 was 0.28, 0.44 and 0.28, respectively. In vitro assays indicated no differences between the C/C and A/A forms in binding transcriptional factors, especially Sp-1 factor, or in promoter activity. Moreover, in this selected population, there was no association between the C to A substitution and serum IL-10 levels. The mean level of IL-10 serum was determined to be 3.87 +/- 1.23 pg/ml in subjects carrying the A/A genotype, 3.47 +/- 0.57 for C/C genotype and 3.13 +/- 0.41 for the heterozygous (C/A genotype). This requires confirmation by comparing to non-asthmatic subjects. We conclude that although the -627 A allele occurs frequently (50% of alleles) in this selected group, in vitro assays and serum IL-10 levels suggest that the -627C-->A substitution represents a silent or neutral variant in the IL-10 promoter.

Anaesthesia for awake craniotomy with non-invasive positive pressure ventilation

Airway management during awake craniotomy is a crucial part of the anaesthetic technique, but it remains the subject of debate. We report two cases of anaesthesia for awake craniotomy using non-invasive positive pressure ventilation; biphasic positive airway pressure or proportional assist ventilation was employed. Both ventilatory techniques provided adequate lung ventilation, smooth transition between anaesthesia and arousal, and patient comfort.

Phasic vagal influence on the rate and timing of reflex swallowing

We investigated the effects of sudden changes in ventilation induced by voluntary hyperpnea and breath-holding on repetitive reflex swallowing elicited by continuous infusion of distilled water into the pharynx in 13 healthy subjects. Ventilation was monitored using a pneumotachograph, and swallowing was identified by submental electromyography with interruption of airflow. We found that voluntary hyperpnea decreased the swallowing frequency whether end-tidal CO(2) tension was maintained at normocapnia or allowed to be hypocapnic. Also, the frequency of swallowing immediately increased with the start of breath-holding, but there was a sudden decrease in swallowing frequency during the hyperpnea observed immediately after the resumption of ventilation (post-breath-holding hyperpnea). The preponderant coupling of swallows with the expiratory phase was lost during voluntary hyperpnea but was maintained during post-breath-holding hyperpnea. These observations may suggest that vagally mediated reflexes are operative in normal physiologic situations and play an important role in the control of swallowing rate as well as in the timing of swallowing in reference to the respiratory cycle.

Notl-Msell methylation-sensitive amplied fragment length polymorhism for DNA methylation analysis of human cancers

We have applied a methylation-sensitive restriction endonuclease, NotI, to the existing amplified fragment length polymorphism (AFLP) method and developed NotI-MseI methylation-sensitive-AFLP (MS-AFLP). NotI-MseI MS-AFLP allows the analysis of DNA methylation alterations at the NotI sites scattered over the genome. Hypermethylation and hypomethylation are visualized by the decrease and increase in the band intensity of DNA fingerprints. Identification of consistent changes can be facilitated through parallel electrophoresis of multiple samples. DNA fragments exhibiting alterations can be cloned from fingerprint bands by amplification of gel-eluted DNA with the same pair of primers used for radioactive fingerprint presentation. Fluorescent NotI-MseI MS-AFLP offers a safer method of studying the alterations in DNA methylation, and may be applied to the hybridization of DNA microarrays in the future. Using NotI-MseI MS-AFLP, we observed frequent hypomethylation of a satellite DNA repeat sequence in a majority of breast tumors.

Molecular genetic basis of porcine histo-blood group AO system

Histo-blood group A and B antigens are oligosaccharide antigens important in transfusion and transplantation medicine. The final steps in the synthesis of these antigens are catalyzed by glycosyltransferases encoded by the functional alleles at the ABO locus. Humans have 3 major alleles (A, B, and O), whereas pigs are known to have only A and O alleles. This paper reports the molecular genetic basis of the porcine AO system. The porcine A gene is homologous to the ABO genes in humans and other species. It encodes an alpha1 --> 3 N-acetyl-D-galactosaminyltransferase that synthesizes A antigens. Southern hybridization experiments using a porcine A gene coding-sequence probe failed to identify a corresponding homologous sequence in genomic DNA from group O pigs, thus suggesting a major deletion in the O gene. Therefore, inadvertent activation of a silent O gene seems unlikely in porcine organs xenotransplanted into humans.

Reduced tolerance of global ischemia in the hypertrophied heart. Effect of coronary flow regulation during reperfusion on postischemic recovery

OBJECTIVE

Reduced coronary reserve during reperfusion may cause postischemic diastolic dysfunction in pressure-overload-induced hypertrophy. We studied the effect of coronary flow regulation (simulated hyperemic or depressed flow) on postischemic cardiac function during reperfusion.

METHODS

Left ventricular pressure overload was induced in 4-week-old rats by abdominal aortic constriction. At 6 weeks of age, isolated Langendorff-perfused hearts (perfusion pressures: 75 mmHg in controls and 110 mmHg in the aortic constriction group) were subjected to hypothermic global ischemia (15 degrees C, 210 min), followed by 2 types of coronary flow regulation during the initial 20 min of reperfusion--manipulated high flow in control hearts (group I), manipulated low flow in control hearts (group II), manipulated high flow in aortic constriction hearts (group III), and manipulated low flow in aortic constriction hearts (group IV) (n = 6/group), and then constant pressure perfusion during the subsequent 45 min of reperfusion. Cardiac function was measured using an isovolumic balloon in the pre- and postischemic periods.

RESULTS

Aortic constriction hearts exhibited greater left ventricular end-diastolic pressure than did control hearts. The increase in left ventricular end-diastolic pressure did not differ between group I (3 +/- 2 mmHg) and group II (-1 +/- 1 mmHg) or between group III (29 +/- 5 mmHg) and group IV (30 +/- 6 mmHg). No difference was seen in postischemic recovery of left ventricular systolic pressure between high and low flow groups in control and aortic constriction hearts.

CONCLUSION

Manipulations in coronary flow during reperfusion did not affect postischemic cardiac function in control or aortic constriction hearts, suggesting that depressed coronary flow during early reperfusion is not a primary cause of postischemic diastolic dysfunction in the hypertrophied myocardium.

Murine equivalent of the human histo-blood group ABO gene is a cis-AB gene and encodes a glycosyltransferase with both A and B transferase activity

We have cloned murine genomic and complementary DNA that is equivalent to the human ABO gene. The murine gene consists of at least six coding exons and spans at least 11 kilobase pairs. Exon-intron boundaries are similar to those of the human gene. Unlike human A and B genes that encode two distinct glycosyltransferases with different donor nucleotide-sugar specificities, the murine gene is a cis-AB gene that encodes an enzyme with both A and B transferase activities, and this cis-AB gene prevails in the mouse population. Cloning of the murine AB gene may be helpful in establishing a mouse model system to assess the functionality of the ABO genes in the future.

The effect of epidural anesthesia on respiratory distress induced by airway occlusion in isoflurane-anesthetized cats

The role of afferent information from the chest wall in the genesis of dyspnea is not fully elucidated. We have developed an animal model for the study of airway occlusion (AO) and proposed new concepts of minimum alveolar anesthetic concentration for AO (MACAOR) and the duration from the start of AO to the onset of the positive motor response (DOCCL) to evaluate respiratory distress quantitatively. We examined the effects of thoracic epidural anesthesia on respiratory distress by using our animal model. Adult cats (n = 24) were anesthetized with isoflurane, and an epidural catheter was placed after T9 laminectomy. After determination of MACAOR, DOCCL was measured. Animals were then randomly assigned into three groups: the EPD Group (n = 12) received epidural 1% lidocaine (0.4 mL/kg), IM saline (0.4 mL/kg), and saline infusion. The IM Group (n = 6) received epidural saline (0.4 mL/kg), IM 1% lidocaine (1 mL/kg), and saline infusion. The PHE Group (n = 6) received epidural 1% lidocaine (0.4 mL/kg) and IV phenylephrine (0.5-1 microg. kg(-1). min(-1)) to maintain a stable arterial blood pressure. DOCCL and MACAOR were measured in each animal at 15 min after the administration of drugs. Plasma lidocaine concentrations were measured before and after epidural or IM injection. DOCCL was significantly longer after epidural injection in all groups than before the injection. Although there was no significant difference in the values of MACAOR between before and after the epidural injection in the EPD Group, the IM administration of lidocaine in the IM Group significantly reduced MACAOR. Plasma concentrations of lidocaine were similar in all groups at all measurement points. Our data indicate that thoracic epidural anesthesia using 1% lidocaine significantly reduced respiratory distress induced by AO. This effect is most likely caused by a systemic effect of lidocaine rather than by reduced afferent information from the chest wall.

IMPLICATIONS

Thoracic epidural anesthesia reduced respiratory distress induced by airway occlusion. This effect is most likely caused by the systemic effect of lidocaine, rather than by the reduced afferent information from the chest wall.

Molecular genetics of ABO

This year commemorates the 100th anniversary of the discovery of the ABO blood group system by Karl Landsteiner. His findings of red cell agglutination by serum and recognition of blood groups laid the scientific basis for safe practice of blood transfusion. Even though dozens of blood systems have been identified, the ABO system still remains to be one of the most important systems in transfusion medicine. In 1990, we elucidated the molecular genetic basis of three major alleles at the ABO locus. Since then we have witnessed the progress in our understanding of ABO genes and A and B glycosyltransferases specified by a variety of functional alleles at this locus. Mutations affecting the activity and specificity of the enzymes have been identified. Not only has ABO genotyping become possible, but it has also become possible to genetically engineer the activity and specificity of the enzymes. We are now at a point of embarking upon the quest of understanding the functional significance of ABO polymorphism.

4,5,9,10-Tetrahydro-1,4-ethanobenz[b]quinolizine as a prodrug for its quinolizinium cation as a ligand to the open state of the TCP-binding site of NMDA receptors

A new derivative of 4,5,9,10-tetrahydro-1,4-ethanobenz[b]quinolizine (2) has been designed as a prodrug for its quinolizinium cation (1) that is a potent antagonist of the TCP-binding site of NMDA receptors at the open state. The 11C-labeled 2 showed high accumulation of radioactivity in the brain in an in vivo biodistribution study. The speculation of 2 as a prodrug of 1 has been proven by the fact that 1 was observed in a high ratio to 2 in an analysis by RP-HPLC of the brain homogenates.

Intracranial vertebral artery dissection presenting as subarachnoid hemorrhage: successful endovascular treatment

INTRODUCTION

Intracranial vertebral artery dissection is a rare condition which may present as subarachnoid hemorrhage. In this situation, treatment is controversial.

CASE REPORT

A case of intracranial right vertebral artery dissection in a 55-year-old woman presenting with subarachnoid hemorrhage is reported. The patient underwent therapeutic occlusion of the dissected artery through microcatheterization using pushing detachable platinum microcoils and had a good outcome. At this moment, the patient has a normal neurologic examination and a control digital subtraction angiography 1 year after the procedure showed an occluded right vertebral artery at V3; there was retrograde flow in the right intracranial vertebral artery up to the origin of a meningeal branch; the artery was thin and had mural irregularities, without any evidence of aneurismatic dilatation.

DISCUSSION

We review the literature and discuss the role of endovascular therapy and other therapeutic options in the treatment of this condition.

Mode of onset of ventricular fibrillation in patients with Brugada syndrome detected by implantable cardioverter defibrillator therapy

OBJECTIVES

We sought to demonstrate the mode of spontaneous onset of ventricular fibrillation (VF) in patients with Brugada syndrome.

BACKGROUND

The electrophysiologic mechanisms of VF in Brugada syndrome have not been fully investigated.

METHODS

Nineteen patients (all male, mean age 47 +/- 12 years) with Brugada syndrome were treated with an implantable cardioverter defibrillator (ICD). The implanted devices were capable of storing electrograms during an arrhythmic event. We investigated the mode of spontaneous onset of VF according to the electrocardiographic features during the episode of VF, which were obtained from stored electrograms of ICDs and/or electrocardiographic (ECG) monitoring.

RESULTS

During a follow-up of 34.7 +/- 19.4 months (range 14 to 81 months), 46 episodes of spontaneous VF attacks were documented in 7/19 (37%) patients. The event-free period between ICD implantation and the first spontaneous occurrence of VF was 14.6 +/- 12.1 months (range 3.7 to 27.4 months). We investigated 33/46 episodes of VF, for which electrocardiographic features (10 to 20 s before and during VF) were obtained from ICDs and/or ECG monitoring in five patients. A total of 22/33 episodes of VF were preceded by premature ventricular contractions (PVCs), which were almost identical to the initiating PVCs of VF. Furthermore, in three patients who had multiple VF episodes, VF attacks were always initiated by the same respective PVC. The coupling interval of the initiating PVCs of VF was 388 +/- 28 ms.

CONCLUSIONS

Spontaneous episodes of VF in patients with Brugada syndrome were triggered by specific PVCs. These findings may provide important insights into the pathophysiological mechanisms causing VF in Brugada syndrome.

Stroke as the first manifestation of calcific aortic stenosis

Heart valve calcifications are rarely recognized as a potential source for cerebral embolism. Previous studies have identified mitral, but not aortic, valve calcifications to be risk factors for stroke. Based on these studies, heart surgery is unlikely to be indicated in patients who present with a stroke and an 'incidental' aortic valve calcification. We report a case of a 46-year-old man presenting with acute onset of left-sided weakness and numbness. A previous smoking history was the only cardiovascular risk factor found. Head CT scan revealed a right middle cerebral artery territory infarct and an adjacent high-density lesion. CT angiography demonstrated the presence of calcific embolic material in the middle cerebral artery. A search for embolic sources revealed a calcific aortic stenosis (CAS). Initially placed on coumadin, the patient developed silent myocardial infarction 2 months later, presumed to be also embolic in origin from the CAS. After aortic valve replacement, the patient has been symptom-free during a 2-year follow-up. In conclusion, CT angiography may be the method of choice for detecting calcific cerebral emboli, and demonstration of a causal relationship between CAS and an embolic stroke by CT angiography may be an important adjunct in surgical decision-making.

Do we need hypothermia in myocardial protection?

BACKGROUND

Since the concept of "elective cardiac arrest" has been introduced by Melrose et al., rapid arrest, hypothermia and additional protection has been employed in surgical myocardial protection in clinical and experimental settings. And cardioplegia technique employed these components improved clinical results of open heart surgery except special cases which require longer cardiac arrest. In 1991, Salemo et al. offered striking impact on most of cardiac surgeon with the report of retrograde continuous warm blood cardioplegia. Since then several reports pointed out the benefit of warm blood cardioplegia although inherent disadvantage of continuous cardioplegia were the inadequate visualization of the operative field. These reports recently lead some cardiac surgeon to intermittent warm blood cardioplegia.

METHODS

This review introduced and examined our experimental and clinical data with reference to establish new surgical myocardial protection.

CONCLUSIONS

Experimental and clinical data might encourage us to employ intermittent tepid (29 ) blood cardioplegia as a practical cardioplegia in open heart surgery.

Transgenic rats carrying copies of the human c-Ha-ras proto-oncogene exhibit enhanced susceptibility to N-butyl-N-(4-hydroxybutyl)nitrosamine bladder carcinogenesis

We have established a transgenic rat line carrying three copies of the human c-Ha-ras proto-oncogene with its own original promoter region, Jcl/SD-TgN(HrasGen)128Ncc (Hras128) rat. c-Ha-ras protein from expression of transduced and endogenous c-Ha-ras genes could be detected in the bladder epithelium of untreated transgenic rats. To examine their susceptibility to N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN)-induced urinary bladder carcinogenesis, male transgenic and wild-type littermates were treated with 0.05% BBN in their drinking water for 10 weeks and then killed at week 20. The numbers and volumes of total macroscopic bladder tumors including both transitional cell papillomas and carcinomas (TCC) per rat were much greater in Hras128 rats than in their wild-type counterparts. The numbers of carcinomas per rat were also significantly greater in Hras128 rats. Two cases of TCC exhibiting invasion of the bladder muscle layer, which is extremely rare in the wild-type animals under the experimental conditions used, were also observed in Hras128 rats. The GGC-->GAC mutations at codon 12 of the transgene were observed in only two TCC out of 21 bladder tumors (9.5%), assessed by RFLP analysis and direct sequencing. SSCP analysis did not show any endogenous c-Ha-ras gene mutations. One of 25 tumors (4.0%) in wild-type rats had an endogenous c-Ha-ras gene mutation at codon 12 that was detected (GGA-->GAA) by single-strand conformation polymorphism and direct sequencing. These results indicate that the Hras128 rat is highly susceptible to BBN carcinogenesis and may be utilized as a rat model for analysis of bladder tumor development. The mutation findings indicate that the enhanced tumor development is not primarily due to mutations occurring in the transgene.

Different mechanisms between premitotic apoptosis and postmitotic apoptosis in X-irradiated U937 cells

PURPOSE

Apoptosis is currently being evaluated for its importance as a pathway of radiation-induced cell death. However, the difference in the mechanisms between premitotic and postmitotic apoptosis following X-irradiation remains not well understood. We show here that the human monoblastoid cell line U937 can be induced to undergo these two different types of apoptosis.

METHODS AND MATERIALS

U937 cells were irradiated at a dose of 5 or 20 Gy, and the DNA fragmentation rate was measured by both flow cytometric analysis and gel electrophoresis. Activation of caspase-3 was detected by Western blot analysis and fluorogenic assay using acetyl-Asp-Glu-Val-Asp-7-amino-4-methyl-coumarin (Ac-DEVD-AMC). Detection of mitochondrial transmembrane potential (DeltaPsi) was performed by using Rho123. Chasing of S-phase fraction following X-irradiation was performed after labeling with 5-bromo-2'-deoxyuridine (BrdU). Thymidine was used for synchronization of the cells. Inhibition of caspase-3 activity was achieved by Acetyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO).

RESULTS

Time courses of the apoptotic rates, caspase activation, and DeltaPsi indicated that two different types of cell death were induced by the different X-ray doses. High-dose X-ray (20 Gy) induced a rapid and strong apoptosis, whereas low-dose X-ray (5 Gy) induced a slow and mild apoptosis. Cell-cycle analyses revealed that there was cell death before cell division in the former apoptosis but the cells must be dying after cell division in the latter apoptosis. By means of cell-cycle synchronization, the S-phase cells proved to be the most sensitive fraction to premitotic apoptosis, but an obvious difference in the susceptibility to cell death among the cell-cycle phases was not observed in postmitotic apoptosis. Ac-DEVD-CHO treatment effectively blocked caspase activity and premitotic apoptosis, but it failed to block postmitotic apoptosis.

CONCLUSIONS

Irradiation of U937 cells at different X-ray doses induced two different types of apoptotic cell death, premitotic apoptosis and postmitotic apoptosis, which are characterized by the time course and cell-cycle specificity. Decision concerning these two types of apoptotic cell death may be made by the difference in the magnitude of cell damage following X-irradiation.

Evaluation of leukocyte-reducing arterial line filter (LG6) for postoperative lung function, using cardiopulmonary bypass

OBJECTIVE

To prevent postoperative pulmonary dysfunction, we have investigated the effect of the Leuko-Guard 6 leukocyte-reducing arterial line filter (LG6) on postoperative lung function.

METHODS

Twenty-six cases of adult valvular heart disease were included in this study. Thirteen cases were operated upon using the LG6 (Group LG), and 13 cases were operated upon using a conventional arterial line filter (Group C). Neutrophil, polymorphonuclear leukocyte elastase and lipoperoxide were measured for this study, and the lung function was evaluated using the Oxygenation Index (PaO2/FiO2).

RESULTS

Statistically significant differences were observed in neutrophil counts between Group LG and Group C (LG = 2225 +/- 572/mm3, C = 3157 +/- 1413/mm3, p = 0.04) at 5 minutes after the onset of cardiopulmonary bypass. In simultaneous blood sampling from the pulmonary artery and the pulmonary vein, the sequestration of neutrophil in the lung decreased in Group LG after the discontinuation of cardiopulmonary bypass. Release of polymorphonuclear leukocyte elastase from the lungs was significantly decreased (p = 0.04) in the Group LG at 1 hour post-bypass. Significant differences were observed in the Oxygenation Index between Group LG and Group C (LG = 398 +/- 72, C = 326 +/- 71, p = 0.019) at 3 hours post-bypass.

CONCLUSION

We concluded that LG6 improved the postoperative lung function, and its mechanism might be derived from the prevention of leukosequestration in the lungs that occurs during the rewarming phase due to selective absorption of activated leukocyte by the LG6.

[Evaluation of paclitaxel and carboplatin in patients with endometrial cancer]

The purpose of this study was to evaluate the combination of paclitaxel and carboplatin in patients with endometrial cancer who have high-risk histopathologic criteria with vessel permeation and low grade, advanced or recurrent disease. The combination of paclitaxel (180 mg/m2 over 3 hours) and carboplatin (dosed at an area under the curve of 5-6) was given intravenously every 3 weeks. Response and toxicity were evaluated according to the Japan Society of Clinical Oncology's response and adverse effect criteria. Eighteen patients were entered in this study and a total of 94 courses were administered. Eleven patients had evaluable lesions. Complete and partial responses were achieved in 5 (45.5%) and 3 (27.3%) patients, respectively. Grade 3 or 4 leukopenia and neutropenia occurred in 49.2% and 90.5% of the patients. G-CSF support was needed in 52.4% of the patients. Only one patient received a platelet transfusion. As a high response rate was obtained, this regimen is considered to be promising treatment for endometrial carcinoma. Prospective comparative study between this combination therapy and the conventional therapy for endometrial carcinoma is warranted.

Expression of human histo-blood group ABO genes is dependent upon DNA methylation of the promoter region

We have investigated the regulatory role of DNA methylation in the expression of the human histo-blood group ABO genes. The ABO gene promoter region contains a CpG island whose methylation status correlates well with gene expression in the cell lines tested. The CpG island was found hypomethylated in some cell lines that expressed ABO genes, whereas the other cell lines that did not express ABO genes were hypermethylated. Whereas constitutive transcriptional activity of the ABO gene promoter was demonstrated in both expressor and nonexpressor cell lines by transient transfection of reporter constructs containing the ABO gene promoter sequence, HhaI methylase-catalyzed in vitro methylation of the promoter region prior to DNA transfection suppressed the promoter activity when introduced into the expressor gastric cancer cell line KATOIII cells. On the other hand, in the nonexpressor gastric cancer cell line MKN28 cells, treatment with DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine resulted in demethylation of the ABO gene promoter and appearance of A-transferase messages, as well as A-antigens synthesized by A-transferase. Taken together, these studies suggest that DNA methylation of the ABO gene promoter may play an important role in the regulation of ABO gene expression.

An effective method for improving hemostasis in aortic root replacement with a composite graft

Hemostasis during aortic root replacement with a composite graft, consisting of a separate Dacron graft and a valve, was markedly improved by using a supra-annular aortic wall reinforcing suture (SAWR). Between February 1994 and January 1998, 14 consecutive patients (10 men and 4 women) underwent replacement of the aortic valve and ascending aorta with the SAWR technique. No intraoperative bleeding of the aortic proximal suture line or early death occurred in this group. No patient required reoperation for bleeding of anastomoses. Three of 10 patients who underwent elective operations were operated on successfully without blood transfusion. In addition, no clinical complications related to the SAWR technique were observed in the follow-up period. We conclude that the SAWR technique can be performed easily and may be an effective method for improving proximal hemostasis.