Intra-articular adenoviral-mediated gene transfer of trail induces apoptosis of arthritic rabbit synovium

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease that primarily affects joints. In rheumatoid joints there is extensive synovial proliferation with diseased synovium becoming highly aggressive, attaching to the articular cartilage and bone to form what is termed a pannus. The formation of active pannus is central to erosive disease and resulting joint destruction. In this study, we examined the ability to eliminate the hyperplastic synovium by adenoviral-mediated gene transfer of human TNF-related apoptosis-inducing ligand (TRAIL), a member of the TNF family that is able to induce apoptosis through interaction with receptors containing death domains, DR4 and DR5. Infection of synovial cells derived from RA patients with Ad.TRAIL resulted in significant apoptosis in three out of five lines. Moreover, primary rabbit synovial fibroblasts were also sensitive to Ad.TRAIL-mediated gene transfer. In a rabbit model of arthritis, intra-articular gene transfer of TRAIL induced apoptosis in cells within the synovial lining, reduced leukocytic infiltration and stimulated new matrix synthesis by cartilage. These results demonstrate that TRAIL can affect the viability of the cells populating the activated synovium in arthritic joints and suggest that the delivery of TRAIL to arthritic joints may represent a non-invasive mechanism for inducing pannus regression.

[Metabolic transformation of (-)-clausenamide in rat liver microsomes]

The metabolic transformation of (-)-clausenamide, isolated from the leaves of Clausena lansium (Lour.) Skeels, was studied in vitro with phenobarbital-induced rat liver microsomal incubate containing the NADPH-generating system. The constitution of the incubation system was optimized and a RP-HPLC-DAD method was developed for the on-line analysis of (-)-clausenamide and its metabolites. The major metabolites were isolated and purified by silica gel column chromatography, preparative TLC and HPLC and their structures were determined as 6-OH clausenamide (CM1) and 5-OH clausenamide (CM2) by 1HNMR and MS.

Identification of metastasis-associated genes in early stage non-small cell lung cancer by subtractive hybridization

Non-small cell lung cancer (NSCLC) is a leading cause of death and a substantial fraction of patients with surgically resected disease ultimately dies due to distant metastasis. To identify gene expression differences in early stage adenocarcinoma that either did or did not metastasize within a 5-year period, we employed a subtractive hybridization strategy of pooled RNA from primary adenocarcinomas (stage I) of the lung. Individual clones (n=225) of the subtracted cDNA library were sequenced. Further analyses of mRNA expression levels in a cohort of 70 NSCLC patients (stage I to IIIA) showed that the metastasis association of the identified genes was stage and histology specific. Cox regression analyses identified two genes (EIF4A1, MALA1) to be independent prognostic parameters for patients' survival in stage I and II disease. These findings could help to identify early-stage NSCLC patients at high risk for the development of distant metastasis.

Atrial fibrillation: a risk factor for increased mortality--an AVID registry analysis

Emerging evidence suggests that atrial fibrillation is not a benign arrhythmia. It is associated with increased risk of death. The magnitude of association is controversial and potential causes remain unknown. Patients in the registry of the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial form the basis for this report. Baseline variables, in particular the presence or absence of a history of atrial fibrillation/flutter, were examined in relation to survival. Multivariate Cox regression was used to adjust for differences in important baseline co-variables using 27 pre-selected variables. There were 3762 subjects who were followed for an average of 773+/-420 days; 1459 (39 %) qualified with ventricular fibrillation and 2303 (61 %) with ventricular tachycardia. A history of atrial fibrillation/flutter was present in 24.4 percent. There were many differences in baseline variables between those with and those without a history of atrial fibrillation/flutter. After adjustment for baseline differences, a history of atrial fibrillation/flutter remained a significant independent predictor of mortality, (relative risk=1.20; 95 % confidence intervals=1.03-1.40; p=0.020). Antiarrhythmic drug use, other than amiodarone or sotalol, was also a significant independent predictor of mortality (relative risk 1.34; 95 % confidence intervals 1.07-1.69, p=0.011. Atrial fibrillation/flutter is a significant independent risk factor for increased mortality in patients presenting with ventricular tachyarrhythmias. This risk may have been overestimated in previous studies that could not adjust for the proarrhythmic effects of antiarrhythmic drugs other than amiodarone or sotalol.

Oligomeric interactions between phospholamban molecules regulate Ca-ATPase activity in functionally reconstituted membranes

Phospholamban (PLB) is a major target of the beta-adrenergic cascade in the heart, and functions as an endogenous inhibitor of Ca-ATPase transport activity. To identify whether oligomeric interactions between PLB molecules are involved in regulating Ca-ATPase transport activity, we have investigated functional interactions between PLB and the Ca-ATPase in proteoliposomes of purified PLB functionally co-reconstituted with the SERCA2a isoform of the Ca-ATPase isolated from cardiac sarcoplasmic reticulum (SR). The calcium sensitivity of this reconstituted preparation and functional stimulation by cAMP-dependent protein kinase (PKA) are virtually identical to those of the Ca-ATPase in cardiac SR microsomes, ensuring the functional relevance of this reconstituted preparation. Interactions between PLB molecules were measured following covalent modification of the single lysine (i.e., Lys(3)) in PLB isolated from cardiac SR membranes with fluorescein isothiocyanate (FITC) prior to co-reconstitution with the Ca-ATPase. FITC modification of PLB does not interfere with the ability of PLB to inhibit the Ca-ATPase, since FITC-PLB co-reconstituted with the Ca-ATPase exhibits a similar calcium dependence of Ca-ATPase activation to that observed in native SR membranes. Thus, the functional arrangement of PLB with the Ca-ATPase is not modified by FITC modification. Using changes in the anisotropy of FITC-PLB resulting from fluorescence resonance energy transfer (FRET) between proximal PLB molecules to measure the average size and spatial arrangement of FITC chromophores, we find that PLB self-associates to form oligomers whose spatial arrangement with respect to one another is in agreement with earlier suggestions that PLB exists predominantly as a homopentamer. The inability of PKA to activate PLB following covalent modification with FITC permits functional interactions between PLB molecules associated with the Ca-ATPase activation to be identified. A second-order loss of Ca-ATPase activation by PKA is observed as a function of the fractional contribution of FITC-PLB, indicating that PKA-dependent activation of two PLB molecules within a quaternary complex containing the Ca-ATPase is necessary for activation of the Ca-ATPase. We suggest that the requirement for activation of two PLB molecules by PKA represents a physiological mechanism to ensure that activation of the Ca-ATPase following beta-adrenergic stimulation in the heart only occurs above a threshold level of PKA activation.

[Audiological findings of the aging across the urban and rural of Suzhou]

OBJECTIVE

To determine the epidemiological characteristics of old people's hearing.

METHOD

Questionnaires, physical examination, audiometry and bio-chemical tests were performed on the elders above 60 years old in part of the urban and rural area of Suzhou with random sample survey.

RESULT

A total of 1,040 individuals was investigated, among which 505 were from urban, and 535 were from rural. 33 of 505 senior citizen (6.53%) were nososacusis, 282 (55.84%) were presbycusis and 21 (4.16%) were noise-induced deafness; In the rural area, 35 of 535 (6.54%) were nososacusis, 232 (43.36%) were presbycusis, and 4 (0.75%) were noise deafness. There was significant difference of the incidence of presbycusis between urban and rural. The audiometric thresholds chart manifested that the threshold elevated with age increasing especially in high-frequency.

CONCLUSION

The etiology of hearing loss of elders was mainly due to presbycusis. The higher incidence of psychotic disorder in urban probably caused a correspondingly higher incidence of presbycusis. So the prevention and cure of some age-induced diseased (e.g. hypertension, arteriosclerosis and diabetes) may be helpful to release and improve presbycusis.

Rapid assembly of structurally defined and highly functionalized conjugated dienes via tethered enyne metathesis

[reaction: see text] Conjugated dienes are versatile building blocks in organic synthesis, and the development of new methods for their synthesis remains an important topic in modern synthetic organic chemistry. We describe here an expedient synthesis of highly functionalized conjugated dienes through sequential silicon-tethered ring-closing enyne metathesis mediated by Grubbs' Ru carbene catalysts and Tamao oxidation. Notable attributes of this methodology include short synthetic manipulations and the structural complexity it confers on the resulting diene moiety.

HIV envelope proteins differentially utilize CXCR4 and CCR5 coreceptors for induction of apoptosis

The involvement of CXCR4 and CCR5 coreceptors in apoptosis induced by the HIV envelope (Env) proteins has not been well defined. We found that simian human immunodeficiency virus (SHIV) virus-like particles (VLPs) containing HIV Env proteins preferentially induce apoptosis of cells corresponding to their coreceptor usage in a CD4+ T cell line. We also demonstrated that induction of apoptosis by SHIV VLPs is correlated with coreceptor usage in a non-T cell line. We examined the effects of SHIV VLPs containing Env proteins derived from either a T-cell-tropic HIV (BH10) strain or a dual-tropic HIV (89.6) strain on induction of apoptosis in recombinant CD4+ human osteosarcoma (HOS) cells expressing either CXCR4 (HOS-CD4.CXCR4) or CCR5 coreceptors (HOS-CD4.CCR5). HOS-CD4.CXCR4 or HOS-CD4.CCR5 cells were activated with concanavalin A and cocultured with VLPs. By TUNEL (TdT-mediated dUTP-X nick end labeling) fluorescence staining and flow cytometry assays, SHIV BH10 VLPs were found to preferentially induce apoptosis in HOS-CD4.CXCR4 cells but not in HOS-CD4 or HOS-CD4.CCR5 cells. On the other hand, SHIV 89.6 VLPs induced an elevated level of apoptosis in both HOS-CD4.CXCR4 and HOS-CD4.CCR5 cells in a dose-dependent fashion. These data demonstrate that T-cell-tropic BH10 Env preferentially utilizes CXCR4, but not CCR5, for induction of apoptosis, whereas dual-tropic 89.6 Env induces apoptosis in both CXCR4- and CCR5-containing cell lines.

Gene transfer of p53 to arthritic joints stimulates synovial apoptosis and inhibits inflammation

Rheumatoid arthritis (RA) is an autoimmune disease that primarily affects joints. During the pathogenesis of rheumatoid arthritis, the synovial lining becomes dramatically thickened and hyperplastic. This highly aggressive tissue invades and destroys articular cartilage and bone. Several lines of evidence suggest that the proliferation of the synovial tissue may be due to disruption in the control of the cell cycle or apoptotic pathways. In particular, mutations in the tumor suppressor protein p53 have been found in synovial tissue from RA joints. We have examined the effects of overexpression of p53 by adenoviral infection in synovial cells in culture and in synovial tissue in vivo in a rabbit model of arthritis. Here we demonstrate that p53 overexpression resulted in significant apoptosis in human and rabbit synovial cells in culture. Furthermore, intraarticular injection of Ad-p53 resulted in extensive and rapid induction of synovial apoptosis in the rabbit knee without affecting cartilage metabolism. Interestingly, a significant reduction in the leukocytic infiltrate was observed within 24 h postinfection of Ad.p53. These results suggest that intraarticular gene transfer of p53 is able to induce synovial apoptosis as well as reduce inflammation and thus may be useful clinically for the treatment of RA.

Direct interaction between endothelial nitric-oxide synthase and dynamin-2. Implications for nitric-oxide synthase function

Endothelial nitric-oxide synthase (eNOS) is regulated in part through specific protein interactions. Dynamin-2 is a large GTPase residing within similar membrane compartments as eNOS. Here we show that dynamin-2 binds directly with eNOS thereby augmenting eNOS activity. Double label confocal immunofluorescence demonstrates colocalization of eNOS and dynamin in both Clone 9 cells cotransfected with green fluorescent protein-dynamin and eNOS, as well as in bovine aortic endothelial cells (BAEC) expressing both proteins endogenously, predominantly in a Golgi membrane distribution. Immunoprecipitation of eNOS from BAEC lysate coprecipitates dynamin and, conversely, immunoprecipitation of dynamin coprecipitates eNOS. Additionally, the calcium ionophore, a reagent that promotes nitric oxide release, enhances coprecipitation of dynamin with eNOS in BAEC, suggesting the interaction between the proteins can be regulated by intracellular signals. In vitro studies demonstrate that glutathione S-transferase (GST)-dynamin-2 quantitatively precipitates both purified recombinant eNOS protein as well as in vitro transcribed (35)S-labeled eNOS from solution indicating a direct interaction between the proteins in vitro. Scatchard analysis of binding studies demonstrates an equilibrium dissociation constant (K(d)) of 27.6 nm. Incubation of purified recombinant eNOS protein with GST-dynamin-2 significantly increases eNOS activity as does overexpression of dynamin-2 in ECV 304 cells stably transfected with eNOS-green fluorescent protein. These studies demonstrate a direct protein-protein interaction between eNOS and dynamin-2, thereby identifying a new NOS-associated protein and providing a novel function for dynamin. These events may have relevance for eNOS regulation and trafficking within vascular endothelium.

[Morphological observation of Mahaim's fibers in 7 cases]

OBJECTIVE

To investigate the Mahaim's fibers of the cardiac conduction system (CCS) of human hearts and study their morphological features.

METHODS

The CCS from 165 cases of sudden death without extracardiac causes and those from 760 cases of non-cardiac death were sampled using a method established by the authors. Serial sections were prepared for histological observation.

RESULTS

Mahaim's fibers were discovered in 7 cases, 5 cases were in the sudden death group, accounting for 3% in that group, 2 cases were in the non-cardiac death group, accounting for 0.26% in that group. All cases belonged to the bundle-ventricular branch type. The characteristics of Mahaim's fibers were found to be as follows. Their transverse diameter was 10 - 35 microns. The bodies of the Mahaim's fibers that originated from A-V bundle were slender with nucleus in the middle of the cell. While the shape of cells from the left bundle branch varied according to the origin of the Mahaim's fiber with size enlarging from up downward. Both types of cells showed abundant lightly stained cytoplasm, similar to A-V bundle and left bundle branch cells. The cells were not bifurcated and some of them were surrounded by a thin layer of fibrous tissue.

CONCLUSION

Mahaim's fibers are not a rarity and it is an abnormal development of an A-V by-path.

[Cerebral watershed infarcts]

OBJECTIVE

To investigate the clinical types and characteristics of cerebral watershed infarcts (CWI).

METHODS

Analysis of the clinical data and imaging characteristics of 192 cases with CWI confirmed by CT scan or MRI.

RESULTS

In 69 cases (35.9%), CWI appeared as wedge-shaped areas on CT scan or MRI, the infarcts located at marginal zones between the anterior and middle cerebral arteries and were usually associated clinically with hemiparesis, transcortical motor aphasia and dementia. In 74 cases (38.5%) the infarcts also appeared as wedge-shaped areas on CT scan and MRI, but located at marginal zones between the middle and posterior cerebral arteries, the patients mainly showed mild hemiparesis and apathy. In 49 cases (25.5%), the long-line or triangle-shaped infarct areas usually located at marginal zones between the superficial and deep territory of the middle cerebral arteries in the basal ganglia and posterolateral angulus frontalis.

CONCLUSION

The presentation of CWI is complicated, and the diagnosis of that mainly depends on imaging studies such as CT scan and MRI.

[Study on gas chromatographic method for the evaluation of residual solvents by using wide bore open tubular columns]

A GC method using wide bore open tubular columns was developed to evaluate residual organic solvents. Sixteen organic solvents commonly used for pharmaceutical synthesis were analysed. The effects of different polarity columns and extraction solvents on the assay of residual solvents were studied in this work. It showed that most solvents can be well separated from each other on non-polar or less polar wide-bore columns. Extraction solvents differed in their extraction recovery and peak shape. Satisfactory results can be obtained when the proposed method was employed and a suitable extraction solvent was selected. The procedures summarized in this paper can be used as a guidance for the evaluation of residual organic solvents in bulk pharmaceuticals.

Three membrane-proximal amino acids in the human parainfluenza type 2 (HPIV 2) F protein are critical for fusogenic activity

In this study, we investigated the role of the membrane-proximal region of the human parainfluenza virus type 2 (HPIV2) F protein by mutational analysis, including deletion, insertion, and substitution. Deletion or replacement of the entire 12 amino acid region (aa 474-485) of the HPIV2 F protein completely abolished its fusion activity when coexpressed with the HPIV2 HN protein. Deletion of groups of four of aa 478-485, single alanine, or other amino acid substitutions among aa 478-485 had minimal or limited effects on HPIV2 F/HN-induced cell fusion. However, a significant reduction in, or complete inhibition of, fusion activity was observed when aa 474-477 were deleted, or the N475, F476, or F477 residues were singly substituted with alanine. In addition, insertions of four amino acids at this region or deletion of eight or more amino acids significantly reduced F protein fusion activity. The oligomerization patterns and levels of cell surface expression of the mutant F proteins were compared to those of the wild-type HPIV2 F protein. The mutant HPIV2 F proteins defective in fusion were also found to be unable to initiate hemifusion, indicating that there is a specific requirement for three specific amino acids as well as the spacing in this region for initiating lipid mixing.

Lead- and device-related complications in the antiarrhythmics versus implantable defibrillators trial

BACKGROUND

Implantation of transvenous implantable cardioverter defibrillators (ICDs) by use of a nonthoracotomy approach has become routine therapy for survivors of life-threatening tachyarrhythmias. The purpose of this study was to identify and prospectively characterize the frequency of lead- and ICD-related complications from the Antiarrhythmics versus Implantable Defibrillators (AVID) Trial.

METHODS AND RESULTS

Between June 1, 1993, and April 7, 1997, 539 patients received nonthoracotomy ICDs either as initial treatment assignment (477) or as crossover from medical management (62). A total of 62 first complications occurred. The subclavian route of insertion resulted in more complications than the cephalic vein route, 46 of 339 (14%) versus 6 of 135 (4%), P = .005, as did the abdominal versus pectoral generator site, 31 of 238 (13%) versus 17 of 291 (6%), P<.02. Most dislodgements and system infections tended to occur in the 3 months after implantation, whereas lead fractures continued to occur throughout follow-up. Failure to use perioperative antibiotics was a predictor of system infection (P = .001).

CONCLUSIONS

These data suggest that cephalic vein access and pectoral generator site may result in fewer complications. The continued occurrence of lead fractures and the need for premature system revision supports the practice of close routine ICD system surveillance.

Common structure in panels of short ecological time-series

Typically, in many studies in ecology, epidemiology, biomedicine and others, we are confronted with panels of short time-series of which we are interested in obtaining a biologically meaningful grouping. Here, we propose a bootstrap approach to test whether the regression functions or the variances of the error terms in a family of stochastic regression models are the same. Our general setting includes panels of time-series models as a special case. We rigorously justify the use of the test by investigating its asymptotic properties, both theoretically and through simulations. The latter confirm that for finite sample size, bootstrap provides a better approximation than classical asymptotic theory. We then apply the proposed tests to the mink-muskrat data across 81 trapping regions in Canada. Ecologically interpretable groupings are obtained, which serve as a necessary first step before a fuller biological and statistical analysis of the food chain interaction.

Induction of long-term protective effects against heterologous challenge in SIVhu-infected macaques

A group of three rhesus macaques were inoculated with SIV isolated from a human (SIVhu) accidentally exposed and infected with SIVsm. Extensive sequence analyses of SIVhu obtained from the human and macaques following infection indicated the presence of truncated nef. Not only did nef fail to repair itself in vivo postinfection (p.i.), but instead, further mutations added additional stop codons with increasing time p.i. Infection of these animals was associated with minimal acute viral replication, followed by undetectable plasma viral loads and only intermittent PCR detection up to 5 years p.i. The three SIVhu infected and three control monkeys were then challenged with the heterologous highly pathogenic SHIV89.6p. All three controls became infected and showed rapid declines in peripheral CD4(+) lymphocytes, disease, and death at 10 and 32 weeks p.i., respectively. In contrast, all three animals previously infected with SIVhu are healthy and exhibit stable CD4(+) lymphocyte levels and undetectable plasma viral loads at >20 months post-SHIV89. 6p challenge. Only transient, low levels of SHIV replication were noted in these animals. Whereas responses to SIVgag/pol were noted, no evidence for SIV/SHIV envelope cross-reactivity was detected by antibody or CTL analyses, suggesting that the protective immune mechanisms to the heterologous challenge isolate were most likely not directed to envelope but rather to other viral determinants.

[Study on the relationship of alteration and expression of p16 gene to pancreatic carcinoma]

OBJECTIVE

To directly investigate the effect of genetic alteration(homozygous deletion and point mutation) and expression of p16 gene on pancreatic carcinomas.

METHODS

Thirty-five cases were analyzed for genetic alteration and expression of p16 gene by polymerase chain reaction(PCR), single strand conformation polymorphism(SSCP), DNA sequencing and immunohistochemical method.

RESULTS

The analysis of pancreatic carcinoma for p16 gene revealed alteration in 19 of 35 cases, among which 12 pancreatic carcinomas had 522 bp homozygous deletion at least and 7 cases had two point mutations at the same site. One of them is 126th codon GTC --> AAT (Val126Asn); the other is 127th codon GCA --> GCG (A127A). The 3D (three-dimensional) structure of P16 protein determined by computer techniques according to PDB indicated that Val126Asn influenced the space structure of P16 protein and affected the function of P16 protein. Twelve cases revealed no P16 protein and 9 cases showed low level expression of P16 protein.

CONCLUSION

The alteration of p16 gene and abnormal expression of P16 protein are significantly correlated with the biological behavior and clinical staging of pancreatic carcinoma and may hence be helpful to prognostication

Phospholamban remains associated with the Ca2+- and Mg2+-dependent ATPase following phosphorylation by cAMP-dependent protein kinase

We have used fluorescence and spin-label EPR spectroscopy to investigate how the phosphorylation of phospholamban (PLB) by cAMP-dependent protein kinase (PKA) modifies structural interactions between PLB and the Ca(2+)- and Mg(2+)-dependent ATPase (Ca-ATPase) that result in enzyme activation. Following covalent modification of N-terminal residues of PLB with dansyl chloride or the spin label 4-isothiocyanato-2,2,6,6-tetramethylpiperidine-N-oxyl ('ITC-TEMPO'), we have co-reconstituted PLB with affinity-purified Ca-ATPase isolated from skeletal sarcoplasmic reticulum (SR) with full retention of catalytic function. The Ca(2+)-dependence of the ATPase activity of this reconstituted preparation is virtually identical with that observed using native cardiac SR before and after PLB phosphorylation, indicating that co-reconstituted sarcoplasmic/endoplasmic-reticulum Ca(2+)-ATPase 1 (SERCA1) and PLB provide an equivalent experimental model for SERCA2a-PLB interactions. Phosphorylation of PLB in the absence of the Ca-ATPase results in a greater amplitude of rotational mobility, suggesting that the structural linkage between the transmembrane region and the N-terminus is destabilized. However, whereas co-reconstitution with the Ca-ATPase restricts the amplitude of rotational motion of PLB, subsequent phosphorylation of PLB does not significantly alter its rotational dynamics. Thus structural interactions between PLB and the Ca-ATPase that restrict the rotational mobility of the N-terminus of PLB are retained following the phosphorylation of PLB by PKA. On the other hand, the fluorescence intensity decay of bound dansyl is sensitive to the phosphorylation state of PLB, indicating that there are changes in the tertiary structure of PLB coincident with enzyme activation. These results suggest that PLB phosphorylation alters its structural interactions with the Ca-ATPase by inducing structural rearrangements between PLB and the Ca-ATPase within a defined complex that modulates Ca(2+)-transport function.

Does snoring predict sleepiness independently of apnea and hypopnea frequency?

Obstructive apneas and hypopneas during sleep are a well recognized cause of excessive daytime sleepiness. Snoring is also associated with excess sleepiness, although it is not known whether this reflects an independent effect of snoring or whether snoring is simply a marker for obstructive sleep apnea. To further explore the relation of snoring to sleepiness, we conducted a cross-sectional cohort study of community-dwelling adults participating in the Sleep Heart Health Study. The study sample comprises 2,737 men and 3,040 women with a mean age of 64 (SD 11) yr. Sleepiness was quantified using the Epworth Sleepiness Scale (ESS). Snoring history was obtained via a self-completion questionnaire. The respiratory disturbance index (RDI), defined as the number of apneas plus hypopneas per hour of sleep, was measured during in-home polysomnography. The ESS score increased progressively with increasing RDI, from a mean of 7.1 (4.2) in subjects with RDI < 1.5 to 8.8 (4.8) in subjects with RDI >/= 15 (p < 0.001). A progressive increase in ESS score was also seen across five categories of snoring frequency, from 6.4 (4.2) in current nonsnorers to 9.3 (4.8) in subjects who snored six to seven nights per week (p < 0.001). The prevalence of excessive daytime sleepiness, defined as an ESS score >/= 11, increased from 15% in never-snorers to 39% in those who snored six to seven nights per week. The relation of snoring to sleepiness was seen at all levels of RDI, with no significant change in the relation of snoring to ESS score after adjustment for RDI in multivariate models. The effects of snoring and RDI on sleepiness were little affected by adjustment for age, sex, race, body mass index, or questionnaire evidence of insufficient sleep time or nocturnal leg jerks or cramps. We conclude that both snoring and RDI are independently associated with excess sleepiness in community-dwelling, middle-aged and older adults.

Vector systems for gene transfer to joints

The prospects for the development of gene therapy treatments for certain orthopaedic diseases have been fueled by advances in the understanding of the molecular components of these disorders. These studies have identified molecules that could have therapeutic or reparative effects in certain settings. The ability to transfer and appropriately express the genes encoding these molecules is dependent on the availability of effective gene transfer vectors. Numerous vector systems have been used to transfer and express genes in joints with varied levels of success. The current review is designed to briefly outline the basics of the different gene transfer vector systems available for use by researchers in the orthopaedic fields.

[Inhibitory effect of panicoin on platelet activation and its mechanism]

OBJECTIVE

To explore the inhibitory pathway and the possible mechanism of panicoin on platelet activation.

METHODS

The effect of panicoin on platelet aggregation, thromboxane B2 release, P-selectin (GMP-140) count, levels of cyclic AMP and cyclic GMP induced by ADP, epinephrine, arachidonic acid (AA) or thrombin were observed.

RESULTS

(1) Panicoin significantly inhibits platelet aggregation induced by ADP, arachidonic acid and epinephrine in a dose-dependent manner; (2) It reduces the P-selectin number on platelet surface which was stimulated by thrombin; (3) It inhibits TXB2 release induced by AA and increases the platelet cyclic AMP level, while cyclic GMP level was not changed.

CONCLUSION

Panicoin shows a potent inhibition on platelet activation and antithrombotic effect. The mechanisms seem to be related with the elevation of platelet cyclic AMP.

Determinants of outcome in patients with sustained ventricular tachyarrhythmias: the antiarrhythmics versus implantable defibrillators (AVID) study registry

BACKGROUND

The prognosis of patients with sustained ventricular tachyarrhythmias varies according to clinical characteristics. We sought to identify predictors of survival in a large population of patients with documented sustained ventricular tachyarrhythmias not related to reversible or correctable causes included in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Registry.

METHODS AND RESULTS

We analyzed the impact of 36 demographic, clinical, and discharge treatment variables on the outcome for 3559 patients. Survival status was assessed with the use of the National Death Index. Multivariate analyses were performed with the use of the Cox proportional hazards model. After a mean follow-up of 17 +/- 12 months, 631 patients died. Actuarial survival was 0.86 (95% confidence interval [CI] 0.85 to 0.88), 0.79 (95% CI 0.78 to 0.81), and 0.72 (95% CI 0.70 to 0.74) at 1, 2, and 3 years. Multivariate predictors of worse survival included older age, severe left ventricular dysfunction, lower systolic blood pressure, history of congestive heart failure, diabetes, smoking or atrial fibrillation, and preexistent pacemaker. The hemodynamic impact of the qualifying arrhythmia was not a predictor of outcome. Defibrillator implantation and hospital discharge while the patient was taking a beta-blocker or an angiotensin-converting enzyme inhibitor were associated with better prognosis.

CONCLUSIONS

Despite therapeutic advances, the mortality rates of patients with sustained ventricular tachyarrhythmias remain high. Prognosis depends on the severity of underlying heart disease, as reflected by the extent of left ventricular dysfunction and the presence of heart failure. Well-tolerated ventricular tachycardia in patients with structural heart disease does not carry a significantly better prognosis than ventricular tachyarrhythmia with more severe hemodynamic consequences.

Filamentous particle formation by human parainfluenza virus type 2

Some paramyxoviruses form long filamentous virus particles: however, the determinants of filament formation and the role of such particles in virus transmission and pathogenicity are not clearly defined. By using conventional immunofluorescence microscopy, we found that human parainfluenza virus type 2 (HPIV2) forms filamentous particles ranging from 5 to 15 microm in length in virus-infected, polarized epithelial cells. The formation of filamentous particles was found to be virus type-specific and was not observed when the same cell types were infected with parainfluenza virus type 3 or Sendai virus, suggesting that different paramyxovirus genera exhibit distinct morphological properties. HPIV2 filamentous particle formation was found to be inhibited by cytochalasin D (CD) or jasplakinolide treatment in a dose-dependent manner. In the presence of 4 microg/ml CD or 1 microM jasplakinolide, the formation of filamentous particles was completely abolished, although similar haemagglutination and p.f.u. titres of virus were found to be released into the culture medium at 24 h post-infection. These observations indicate that host cell components, including the actin microfilament network, are important determinants of the morphology of parainfluenza viruses. The predominance of filamentous particles in polarized epithelial cells may reflect specific pathogenic roles of these particles in infection of human epithelial tissues.

Adenoviral mediated delivery of FAS ligand to arthritic joints causes extensive apoptosis in the synovial lining

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease where the synovial lining layer of the joint becomes thickened, hypercellular, and highly aggressive. Invading synovial tissue erodes cartilage and subchondral bone and leads to loss of joint function. FasL, a cell-surface molecule on activated T-cells interacts with its receptor, Fas, to induce apoptosis in target cells. We addressed the feasibility of using adenoviral gene transfer of FasL therapeutically to mediate apoptosis in arthritic joints similar in size to the small joints of the hands and feet that are the primary sites of RA in humans.

METHODS

Adenoviral vectors were used to transfer FasL and LacZ cDNAs into human RA and rabbit synovial fibroblasts in culture where apoptosis was evaluated using MTT and TUNEL analyses. The ability of Ad.FasL to mediate synovial apoptosis in vivo was then addressed in an IL-1-induced arthritis model in the rabbit knee.

RESULTS

In culture, delivery of FasL was found to efficiently induce apoptosis in both human RA and rabbit synovial fibroblasts. The ability of Ad.FasL to induce synovial apoptosis was then evaluated in rabbit knee joints. 24 h after intra-articular injection of 10(11) Ad.FasL particles, large regions of synovial tissue were observed histologically consisting primarily of fibrous matrix and cellular debris. TUNEL staining of corresponding sections was highly positive for fragmented DNA. Glycosaminoglycan (GAG) synthesis from cartilage shavings from treated joints suggests that Ad.FasL does not induce significant apoptosis in resident articular chondrocytes.

CONCLUSIONS

Infection of human and rabbit synovial fibroblasts with Ad.FasL results in significant apoptotic cell death in vitro. Direct intra-articular injection of Ad.FasL in the arthritic rabbit knee results in extensive apoptosis in the synovium without affecting chondrocyte viability.

Production and characterization of simian--human immunodeficiency virus-like particles

We have produced and characterized, in a baculovirus expression system, simian-human immunodeficiency virus-like particles (SHIV VLPs) containing SIV Gag and HIV envelope (Env) proteins. Recombinant SIV gag (SIVmac239) and full-length or cytoplasmic domain-truncated HIV env from either HIV BH10 or HIV 89.6 virus were coexpressed in insect cells and Env incorporation into released SHIV VLPs was characterized. The expression level of the Env protein was found to be about 20-50% higher in both strains producing the truncated Env. Cell surface expression of the truncated Env proteins was found to be about eightfold higher than that of the full-length Env proteins. Furthermore, the truncated Env proteins exhibited higher levels of cleavage into gp120 and gp41 compared with the full-length Env. The SHIV VLPs produced by the coexpression of SIV gag and truncated HIV env contained both precursor (gp160) and gp120, while predominantly gp160 was found in the VLPs containing full-length Env. Coinfection of a recombinant virus expressing the protease furin also resulted in more efficient cleavage of gp160 to gp120. Both full-length and truncated Env were found to induce CD4+ cell fusion. Analysis of VLPs by immunoelectron microscopy demonstrated the incorporation of both full-length and truncated Env on the surface of VLPs. Truncated Env also was incorporated at higher levels on the surfaces of VLPs than full-length Env. The assembly of VLPs containing biologically active Env proteins may be useful in vaccine development and in functional studies of the HIV envelope protein.

Microglia exhibit clonal variability in eliciting cytotoxic T lymphocyte responses independent of class I expression

Microglia are important immunoregulatory cells within the central nervous system (CNS). Viral infection of primary microglia and splenic macrophage clones revealed that both exhibited a heterogeneous, but relatively low, sensitivity to cytolysis mediated by CD8(+) cytotoxic T lymphocytes (CTL). The majority of clones were poor in processing and presenting epitopes, despite triggering lysis when coated with peptide. These characteristics were retained by stable microglia lines. Reduced lysis did not correlate with class I expression and IFN-gamma treatment only partially enhanced recognition. In contrast, targeting the epitope into the endoplasmic reticulum restored cytolysis to levels achieved with exogenous peptide. An inherent resistance to cytolysis was revealed by efficient engagement of T cells in competition assays and the inability of saturating peptide to enhance cytolysis. These data suggest that microglia heterogeneity in antigen processing, in addition to low sensitivity to CTL lysis, contributes to limited CD8(+) T cell responses and viral CNS persistence.

Age-related variation in the interstitial tissues of the cardiac conduction system; and autopsy study of 230 Han Chinese

The amount of fatty and fibrous tissues in 230 Han Chinese who died of noncardio-vascular diseases has been studied by a semi-quantitative method and analysed by chi-square test. The results have shown some consistency. Generally, in the sino-atrial node (SAN), fibrosis and fatty influtratin appear only after 40 years of age and increase one grade with every 20 years. The atrio-ventricular node (AVN) showed fatty change after 30 years of age and fibrosis appeared after 60. In the His bundle (HB), fatty infiltration and fibrosis appear after 40 years. The left bundle branch (LBB) showed similar changes. The appearance of fibrosis in the AVN seems to be later than that reported by Lev.

In-hospital versus out-of-hospital presentation of life-threatening ventricular arrhythmias predicts survival: results from the AVID Registry. Antiarrhythmics Versus Implantable Defibrillators

OBJECTIVES

This study describes the outcomes of patients from the Antiarrhythmics Versus Implantable Defibrillators (AVID) Study Registry to determine how the location of ventricular arrhythmia presentation influences survival.

BACKGROUND

Most studies of cardiac arrest report outcome following out-of-hospital resuscitation. In contrast, there are minimal data on long-term outcome following in-hospital cardiac arrest.

METHODS

The AVID Study was a multicenter, randomized comparison of drug and defibrillator strategies to treat life-threatening ventricular arrhythmias. A Registry was maintained of all patients with sustained ventricular arrhythmias at each study site. The present study includes patients who had AVID-eligible arrhythmias, both randomized and not randomized. Patients with in-hospital and out-of-hospital presentations are compared. Data on long-term mortality were obtained through the National Death Index.

RESULTS

The unadjusted mortality rates at one- and two-year follow-ups were 23% and 31.1% for patients with in-hospital presentations, and 10.5% and 16.8% for those with out-of-hospital presentations (p < 0.001), respectively. The adjusted mortality rates at one- and two-year follow-ups were 14.8% and 20.9% for patients with in-hospital presentations, and 8.4% and 14.1% for those with out-of-hospital presentations (p < 0.001), respectively. The adjusted long-term relative risk for in-hospital versus out-of-hospital presentation was 1.6 (95% confidence interval [CI] 1.3-1.9).

CONCLUSIONS

Compared with patients with out-of-hospital presentations of life-threatening ventricular arrhythmias not due to a reversible cause, patients with in-hospital presentations have a worse long-term prognosis. Because location of ventricular arrhythmia presentation is an independent predictor of long-term outcome, it should be considered as an element of risk stratification and when planning clinical trials.

Sites on the cytoplasmic region of phospholamban involved in interaction with the calcium-activated ATPase of the sarcoplasmic reticulum

Proton NMR studies have shown that when a peptide corresponding to the N-terminal region of phospholamban, PLB(1-20), interacts with the Ca2+ATPase of the sarcoplasmic reticulum, SERCA1a, docking involves the whole length of the peptide. Phosphorylation of Ser16 reduced the affinity of the peptide for the pump by predominantly affecting the interaction with the C-terminal residues of PLB(1-20). In the phosphorylated peptide weakened interaction occurs with residues at the N-terminus of PLB(1-20). PLB(1-20) is shown to interact with a peptide corresponding to residues 378-405 located in the cytoplasmic region of SERCA2a and related isoforms. This interaction involves the C-terminal regions of both peptides and corresponds to that affected by phosphorylation. The data provide direct structural evidence for complex formation involving residues 1-20 of PLB. They also suggest that phospholamban residues 1-20 straddle separate segments of the cytoplasmic domain of SERCA with the N-terminus of PLB associated with a region other than that corresponding to SERCA2a(378-405).

Beta-blocker use and survival in patients with ventricular fibrillation or symptomatic ventricular tachycardia: the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial

OBJECTIVES

To evaluate whether use of beta-adrenergic blocking agents, alone or in combination with specific antiarrhythmic therapy, is associated with improved survival in persons with ventricular fibrillation (VF) or symptomatic ventricular tachycardia (VT).

BACKGROUND

The ability of beta-blockers to alter the mortality of patients with VF or VT receiving contemporary medical management is not well defined.

METHODS

Survival of 1,016 randomized and 2,101 eligible, nonrandomized patients with VF or symptomatic VT followed in the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial through December 31, 1996 was assessed using Cox proportional hazards analysis.

RESULTS

The 817 (28%) patients discharged from hospital receiving beta-blockers had less ventricular dysfunction, fewer symptoms of heart failure and a different pattern of medication use compared with patients not receiving beta-blockers. Before adjustment for important prognostic variables, beta-blockade was not significantly associated with survival in randomized or in eligible, nonrandomized patients treated with specific antiarrhythmic therapy. After adjustment, beta-blockade remained unrelated to survival in randomized or in eligible, nonrandomized patients treated with amiodarone alone (n = 1142; adjusted relative risk [RR] = 0.96; 95% confidence interval [CI] 0.64-1.45; p = 0.85) or a defibrillator alone (n = 1347; adjusted RR = 0.88; 95% CI 0.55 to 1.40; p = 0.58). In contrast, beta-blockade was independently associated with improved survival in eligible, nonrandomized patients who were not treated with specific antiarrhythmic therapy (n = 412; adjusted RR = 0.47; 95% CI 0.25 to 0.88; p = 0.018).

CONCLUSIONS

Beta-blocker use was independently associated with improved survival in patients with VF or symptomatic VT who were not treated with specific antiarrhythmic therapy, but a protective effect was not prominent in patients already receiving amiodarone or a defibrillator.

[Low level of residual renal function in the initial month and high transport characteristic as important causes of peritoneal dialysis failure]

OBJECTIVE

To evaluate what kind of patients was at high risk on peritoneal dialysis (PD) treatment.

METHODS

96 patients on PD for (23.1 +/- 10.0) months were studied. The patients were divided into two groups. Group A: patients (25) who died or switched to hemodialysis because of cardiovascular disease, malnutrition, ultrafiltration inefficiency, hydrothora, relapsing peritonitis, etc. Group B: stable PD patients (71) up to now. Age, body surface area (BSA) and dialysate fill volume (DV) were not different between the two groups. The nutritional status, dialysis adequacy, peritoneal membrane transport characteristics, and residual renal function (RRF) in the initial month of dialysis were compared. Patient survival rate was studied by Kaplan-Meier method.

RESULTS

It was demonstrated that Kt/V and Ccr in group A were lower than those in group B (P < 0.05). Meanwhile, RRF was significantly different between the two groups; patients with better RRF (> or = 2 ml/min) had higher survival. The percentage of high transporters in group A was greater than in group B.

CONCLUSION

Higher clearance in the initial month of dialysis seems to keep PD successful. PD failure maybe related to high transport characteristic and its treatment modality is DAPD. Hemodialysis will be a better choice when RRF is very low as water balance is poorly controlled by DAPD.

[The meaning of the expression of PCNA and c-erbB-2 in the hyperplasia of laryngeal epithelium]

OBJECTIVE

This study was performed to examine the relationship between PCNA and c-erbB-2 expression and histological diagnosis.

METHOD

The percentages of PCNA-positive nuclei (PCNA index) were evaluated in biopsies of 10 with epithelial simple hyperplasia, 26 with dysplasia and 30 with squamous carcinoma by immunohistochemical staining.

RESULT

The PCNA indices were 6.64%, 29.36% and 62.67% respectively. There were significant statistic correlation between these indices and their histological gradies of lesions (P < 0.01). C-erbB-2 was not positive in all of dysplastic lesion and weak in carcinoma (20%).

CONCLUSION

The PCNA activity in dysplastic lesions of laryngeal premalignancis is higher than that in simple hyperplastic lesions but lower than that in carcinoma. The severe dysplasia with high PCNA indices should be treated clinically as the early invasive carcinom. The method should be regarded as a useful adjunct to traditional histological techniques with allowing more objective grading of epithelial hyperplastic lesions of larynx. There was no relationship between c-erbB-2 expression and histolotical diagnosis of hyperplastic lesions.

[The analysis of pathological changes of cardiac conduction system in 54 cases of cardiac sudden deaths]

OBJECTIVE

To elucidate the exact cause of death in cases of cardiac sudden deaths.

METHODS

Sampling of cardiac conduction system (CCS) designed by the research group was adopted. The CCS of 120 cases died of cardiac sudden deaths were collected for routine histological examination.

RESULTS

In 54 out of 120 cases, the causes of death were attributed to lesions present in the CCS, and 85.2% of them were young adults. The peak age range was from 20 - 30. Much more in males (6.7:1). The pathological changes in CCS include: inflammation (46.2%), fatty infiltration, hypertrophic cardiomyopathy associated with CCS changes; hemorrhage, developmental anomalies, fibrosis and tumors.

CONCLUSION

The pathological changes of CCS are relatively common, as the cause of sudden deaths. Which is considered to be the pathological basis of the unstable cardiac electric potentials and arrhythmia. This study recommended the necessity of routine examination on CCS in cases of sudden deaths.

Selection of CD8+ T cells with highly focused specificity during viral persistence in the central nervous system

The relationships between T cell populations during primary viral infection and persistence are poorly understood. Mice infected with the neurotropic JHMV strain of mouse hepatitis virus mount potent regional CTL responses that effectively reduce infectious virus; nevertheless, viral RNA persists in the central nervous system (CNS). To evaluate whether persistence influences Ag-specific CD8+ T cells, functional TCR diversity was studied in spleen and CNS-derived CTL populations based on differential recognition of variant peptides for the dominant nucleocapsid epitope. Increased specificity of peripheral CTL from persistently infected mice for the index epitope compared with immunized mice suggested T cell selection during persistence. This was confirmed with CD8+ T cell clones derived from the CNS of either acutely (CTLac) or persistently (CTLper) infected mice. Whereas CTLac clones recognized a broad diversity of amino acid substitutions, CTLper clones exhibited exquisite specificity for the wild-type sequence. Highly focused specificity was CD8 independent but correlated with longer complementarity-determining regions 3 characteristic of CTLper clonotypes despite limited TCR alpha/beta-chain heterogeneity. Direct ex vivo analysis of CNS-derived mononuclear cells by IFN-gamma enzyme-linked immunospot assay confirmed the selection of T cells with narrow Ag specificity during persistence at the population level. These data suggest that broadly reactive CTL during primary infection are capable of controlling potentially emerging mutations. By contrast, the predominance of CD8+ T cells with dramatically focused specificity during persistence at the site of infection and in the periphery supports selective pressure driven by persisting Ag.

[An experimental study on effect of methazolamide on decreasing intraocular pressure in rabbits]

OBJECTIVE

To study the therapeutic effect of methazolamide on glaucoma.

METHODS

Various doses of methazolamide were orally administered in rabbits, their effects on high intraocular pressures and on recovery of low intraocular pressures were observed.

RESULTS

The high intraocular pressures were significantly decreased and the maintenance of low intraocular pressure was significantly prolonged by the oral administration of 40, 20, 10 mg/kg of methazolamide. A dose-effect relationship that is the reduction of intraocular pressure increases with the increase of the dosage administration of methazolamide could be observed.

CONCLUSION

This study indicates that methazolamide might play an effective therapeutic role in glaucoma.

Affinity purification of the Ca-ATPase from cardiac sarcoplasmic reticulum membranes

We report the isolation of the functional form of the Ca-ATPase from porcine cardiac sarcoplasmic reticulum (SR) membranes, taking advantage of the ability of this enzyme to bind to the nucleotide site affinity dye, Reactive Red 120. Conditions that optimize the solubility and functional stability of the cardiac Ca-ATPase in detergent during the purification procedure are essential to its recovery. The purified Ca-ATPase migrates as a single band on Coomassie blue-stained polyacrylamide gels and exhibits high specific activity (2.5 IU at 25 degreesC) and functional stability. Similar enrichment of the Ca-ATPase estimated from either relative amounts of the 100-kDa protein band on polyacrylamide gels or steady-state concentrations of phosphorylated enzyme intermediate (E-P) demonstrate that neither nonfunctional Ca-ATPases nor non-Ca-ATPase proteins migrating with an apparent molecular weight of 100 kDa constitute a significant fraction of these preparations. Steady-state levels of E-P are 1.3 and 8.6 nmol/mg protein, respectively, for native cardiac SR membranes and the final purified fraction. These values, in comparison to the maximum value (9.1 nmol/mg) for the 110-kDa protein, agree well with estimates of total Ca-ATPase abundance from gel densitometry for both preparations and indicate full site reactivity, i.e., one phosphorylation site for each 110-kDa cardiac Ca-ATPase polypeptide chain.

[Chemical constituents of Phyllanthus urinaria L. and its antiviral activity against hepatitis B virus]

Studies on the chemical constituents of Phyllanthus urinaria and its antiviral activity against hepatitis B virus were completed. Eleven compounds have been isolated. Two of them are new compounds methyl ester dehydrochebulic acid and methyl brevifolin carboxylate. Antiviral experiments on HBsAg in vitro and liver damage caused by CCl4 have shown that. Phyllanthus urinaria possesses antiviral activities against HBV.

Microencapsulation of rat islets prolongs xenograft survival in diabetic mice

OBJECTIVE

To protect the transplanted islets from the host's immune system by means of immunoexclusion membranes.

METHODS

Rat islets were isolated from Wistar rat pancreas by ductal collagenase distention, stationary digestion, and finally with the aid of dextran gradient separation. Then the islets were encapsulated in alginate-polylysine-alginate (APA) semipermeable membranes.

RESULTS

In vitro studies demonstrated that encapsulated islets secreted insulin in response to glucose challenge for at least 8 weeks, which was similar to free islets. In vivo studies showed that 15 streptozotocin (STZ)-induced diabetic mice were transplanted intraperitoneally with 1000 encapsulated islets without immunosuppression. Diabetes was reversed within 3 days, and the mice remained normoglycemic for up to 160 days, with a mean xenograft survival time of 126 days. The encapsulated islets had a significantly greater effect than unencapsulated islets, which functioned for less than 8 days.

CONCLUSIONS

Encapsulation of pancreatic islets in semipermeable membranes can effectively prolong xenograft survival without immunosuppression in an animal model.

[Retrocaval ureter]

OBJECTIVE

To improve the diagnosis of retrocaval ureter.

METHOD

20 cases of retrocaval ureter with an average age of 33.4 years were reported. The diagnosis of this disease depends on urography and retrograde ureterography. Operation was the principal treatment. Ureter orthopedics and reduction were performed in 19 cases of type 1 (low loop) except one case of type II (high loop). After removing 3 - 4 cm retrocaval ureter with pathological changes, we anastomosed the ureter without tension and regained its normal anatomic position.

RESULT

B-ultrasound and excretory urography showed no stenosis and improvement of hydronephrosis.

CONCLUSION

Ureter orthopedics and reduction are ideal for the treatment of retrocaval ureter.

[Morphological observations of tumors in the cardiac conduction system]

OBJECTIVE

To investigate the incidence of tumors in the cardiac conduction system (CCS) and to study their relation to sudden deaths.

METHODS

The CCS from 149 cases of sudden death without extracardiac cause of deaths and those from 737 cases of non-cardiac death were sampled using technique designed by the authors. Routine histological examinations were carried out.

RESULTS

Tumors in the CCS were found in 12 cases (1.35%). Another case with tumor in the CCS was found in a specimen received for consultation. Of these 13 tumors, 10 were primary benign tumors affecting the CCS, 3 were metastatic tumors. The benign tumors included fibroma, hemangioma, lipomatous hypertrophy of the atrial septum, mesothelioma and rhabdomyoma. 8 of the 10 cases were located in the SAN or AVN. All the metastatic tumors were in the SAN. Of the 13 cases, 3 died suddenly.

CONCLUSION

Tumors in the CCS are the smallest tumors which can cause sudden death.