Tribological and corrosion performance of the plasma-sprayed conformal ceramic coating on selective laser melted CoCrMo alloy.

Ceramic implants have superior performance due to the excellent wear resistance and biocompatibility. However, the poor machinability limits their applications. Plasma sprayed ceramic coating on the additively manufactured metal substrate not only provides a 3-dimensional conformal implant coating and but also forms a highly wear-resistant surface layer. In this paper, three types of ceramic coatings of Al2O3, ZrO2, and Al2O3-ZrO2 composite have been fabricated by atmosphere plasma spray on the CoCrMo alloy substrate prepared by selective laser melting (SLM). It has been found that the Al2O3-ZrO2 composite coating has better corrosion and wear resistance compared with the ceramic coating (Al2O3, ZrO2) and the CoCrMo substrate. The adhesion strength between the Al2O3-ZrO2 composite coating and the substrate reaches 238 MPa. In addition, the wear and corrosion resistance increase with wear progression for all the fabricated ceramic coatings. The highly dense microstructure, fewer microcracks, and the amorphous phases are deterministic factors responsible for the superior tribological and corrosion performance of the Al2O3-ZrO2 composite coating. The fabrication route has been proved very promising to manufacture high-performance implants with ceramic coating.

Target antifungal peptides of immune signalling pathways in silkworm, Bombyx mori, against Beauveria bassiana.

Antifungal innate immunity is an important defence used by insects against entomogenous fungi. However, the downstream target antifungal peptides of different immune signalling pathways are unknown. We found that the Toll, Janus kinase/signal transducer and activator of transcription (Jak/STAT) and Immunodeficiency (IMD) signalling pathways in the silkworm, Bombyx mori, can be activated by Beauveria bassiana. Inhibition of the Toll, IMD and Jak/STAT signalling pathways reduced the antifungal activities of silkworm haemolymph. We verified the target antifungal peptides of different immune signalling pathways. The expression patterns of five anti-fungal peptide genes in silkworm larvae and BmN cells were detected after blocking or over-expressing the immune signalling pathways. The Toll signalling pathways mediated the expression of Bmcecropin A, Bmattacin 1 and Bmgloverin 2; IMD signalling pathways mediated Bmenbocin 1, Bmgloverin 2 and Bmattacin 1; Jak/STAT signalling pathways mediated Bmstorage protein 30K-19G1 (Bmsp 1), Bmattacin 1 and Bmcecropin A. These data indicated that anti-microbial peptide genes in B. mori evolved through expansion and selection of existing genes to adapt to the challenge of invasive microorganisms such as fungi. This information provides insight into the antifungal immune responses in B. mori and aids understanding of insect immune regulation mechanisms.

Spatiotemporal dynamics and risk factors of rotavirus A circulation in backyard pig farms in a Philippine setting.

Rotavirus A is one of the leading etiological agents of porcine gastroenteritis, a condition which results to stunted growth among piglets. Moreover, there is increasing evidence for zoonosis of rotavirus A (RVA), which is also the principal cause of diarrhea in children. In the absence of rigorous animal health monitoring in Philippine backyard farms, there is therefore a strong need for RVA surveillance. In this study, 30 randomly selected backyard farms were subjected to surveillance for RVA for 12 months. Results show that RVA detection at a monthly farm-level rate ranged from 0 to 52%, with an overall average of 23%. RVA had higher detection rates in adult pigs compared to young piglets and was most prevalent in non-diarrheic stools, indicating asymptomatic circulation of the virus. Spatiotemporal analysis demonstrated that the viral circulation exhibits a seasonal pattern that peaks and forms geographical clusters during the cooler months of the year, suggesting farm-to-farm transmission. Risk factor analysis identified specific farm conditions that increase the likelihood of RVA circulation: presence of gilts, larger herd size, presence of other animals, and abiotic factors such as low relative humidity and low altitude. The same analysis also revealed three major management practices that can help reduce the pressure of infection in these farms: sanitation and waste disposal, animal grouping, and diet. This new perspective on porcine RVA circulation will benefit the underprivileged backyard farmers and help empower them to protect both animal and public health.

Prevalence and clinical correlation of dysphagia in Parkinson disease: a study on Chinese patients.

BACKGROUND/OBJECTIVES: Dysphagia is relatively common in patients with Parkinson disease (PD) and can have a negative impact on their quality of life; therefore, it is imperative that its prevalence in PD patients is studied. The aim of this study was to explore the prevalence and clinical correlation of dysphagia in Chinese PD patients. SUBJECTS/METHODS: We recruited 116 Chinese PD patients. A videofluoroscopic study of swallowing (VFSS) was used to identify dysphagia. Assessments, including water drinking test, relative motor symptoms, non-motor symptoms (NMS) and quality of life, were performed to analyze the risks of dysphagia. RESULTS: The prevalence of dysphagia was 87.1%. The comparison of demographic and clinical features between patients with and without dysphagia included sex, education level, disease course, Mini-mental State Examination (MMSE), Hamilton Depression Scale (HAMD), Hamilton Anxiety Scale (HAMA), Question 6, 7 of the Unified Parkinson Disease Rating Scale (UPDRS Part II), Hoehn-Yahr stage (H&Y), water drinking test, 39-item Parkinson Disease Questionnaire (PDQ-39) and Non-Motor Symptoms Quest (NMSQ). We found significant correlations between dysphagia and age. Using age, disease course, and H&Y stage as the independent variable in our regression analysis for assessing the risk factors of dysphagia in PD patients, age and H&Y stage displayed a strong correlation as the risk factors. The risk of dysphagia in elderly PD patients is 1.078 times greater than that of younger PD patients. Also, the risk of dysphagia in PD patients of a greater H&Y staging is 3.260 times greater than that of lower staging PD patients. CONCLUSIONS: Our results suggest that dysphagia is common in Chinese PD patients. Older patients or those in higher H&Y stages are more likely to experience dysphagia. There is no correlation between dysphagia and PD duration.

[Alterations of miRNA profiles and function analysis in paraquat-induced apoptosis of hNPCs].

Objective: To investigate the impacts of paraquat on microRNA profiles in apoptosis of human neural progenitor cells (hNPCs) and to explore miRNA targets and biological functions. Methods: We used hNPCs as a popular in vitro cell model system for characterizing the neurotoxicity. Cell apoptosis was detected by Annexin V-APC/7-AAD after 24 h treatment with different concentrations of PQ (0, 5, 10, 20, 40, 80 µmol/L). Microarray profiling expression of PQ treated cell line and their corresponding control was determined and differentially expression miRNAs were confirmed by quantitatively real-time PCR. The target genes regulated by aberrantly expressed miRNAs were predicted by on line-available software (Target Scan, Miranda, Mirbase). The GO and KEGG pathway database were used to analyze the functions of target genes. Meanwhile, the apoptosis-related protein expressions were evaluated by western blot. Results: cell apoptosis increased with increasing PQ concentrations (from 10 to 80µmol/L) in a dose-dependent manner (P<0.05). miRNA microarray showed that 40 miRNAs were significantly up-regulated while 26 miRNAs were down-regulated after 20 µmol/L PQ treatment (P< 0.05). We selected 6 differentially expressed miRNAs to validate with qRT-PCR. The results were consistent with microarray data for all miRNAs tested. Bioinformatics analysis demonstrated target genes were enriched in regulation of neuron apoptosis and differentiation, MARK signaling pathway as well as P53 signaling pathway. The protein expressions of bax and caspase3 significantly increased while bcl-2 significantly decreased treated with PQ compared with control group (P<0.05). Conclusion: There is a specific miRNA expression profile in paraquat-induced apoptosis of hNPCs. Differentially expression miRNAs regulated apoptosis of hNPCs through multiple molecular signaling pathways and especially for mitochondrial apoptosis pathway.

Pyrrolidine dithiocarbamate attenuates paraquat-induced acute pulmonary poisoning in vivo via transforming growth factor ß1 and nuclear factor κB pathway interaction.

Paraquat (PQ) exposure could cause pulmonary fibrosis. The aim of this study was to investigate the protective effect of pyrrolidine dithiocarbamate (PDTC) in an acute PQ poison model. One hundred and forty-four Sprague Dawley rats were equally divided into three experimental groups: control group, PQ group, and PQ + PDTC group. At days 1, 3, 7, 14, 28, and 56 of treatment, the serum levels of transforming growth factor ß1 (TGF-ß1), the levels of hydroxyproline, the protein expression of nuclear factor κB (NF-κB) pathway, and histopathological change in lung tissue were assessed. The survival rate of rats treated with PQ + PDTC was increased compared with that of rats treated only with PQ (p < 0.05), and the occurrence of pathological changes was dramatically attenuated in the PQ + PDTC group. The serum levels of TGF-ß1 and the hydroxyproline levels in the PQ group were significantly increased in a time-dependent manner compared with those in the control and PQ + PDTC groups on days 7, 14, 28, and 56 (p < 0.05). Additionally, the protein levels of NF-κB proteins p65, inhibitor of κB (IκB) kinase (IKKß, and IκB-α were significantly downregulated in the PQ + PDTC group as determined by array analysis. The present findings suggest that overexpression of TGF-ß1 may play an important role in PQ-induced lung injury and that PDTC, a strong NF-κB inhibitor, can rescue PQ-induced pulmonary fibrosis by influencing the protein expression of NF-κB pathway.

How to simplify the diagnostic criteria of hypertension in adolescents.

Diagnosis of hypertension in adolescents is complicated because blood pressure values vary with age, gender and height. How can we simplify the diagnostic criteria for hypertension in adolescents? In 2006, anthropometric measurements were assessed in a cross-sectional population-based study of 3136 Han adolescents aged 13-17 years. Hypertension was defined according to the 2004 National High Blood Pressure Education Program Working Group definition. The following equations for blood pressure-to-height ratio (BPHR) were used: systolic BPHR (SBPHR)=SBP (mm Hg)/height (cm) and diastolic BPHR (DBPHR)=DBP (mm Hg)/height (cm). Receiver-operating characteristic curve analyses were performed to assess the accuracy of SBPHR and DBPHR as diagnostic tests for elevated systolic blood pressure (SBP) and diastolic blood pressure (DBP), respectively. After the cutoff points were determined, hypertension was defined by SBPHR/DBPHR, and the sensitivity and specificity were calculated. The accuracy of SBPHR and DBPHR (assessed by area under the curve) for identifying elevated SBP and DBP was >0.85 (0.989-1.000). The optimal thresholds of SBPHR/DBPHR for defining hypertension (stages 1 and 2) were 0.75/0.48 for boys and 0.78/0.51 for girls, and for defining hypertension (stage 2) were 0.81/0.57 for boys and 0.84/0.63 for girls. In identifying hypertension, the sensitivity and specificity were both >90% (91.0-99.1%). In identifying stage 2 hypertension, when the sensitivity was 100%, the specificity was 98.6% for boys and 99.1% for girls. BPHR is a simple, accurate and non-age-dependent index for screening hypertension in Han adolescents, especially for stage 2 hypertension.

Biomechanical analysis and injury prevention in off-highway vehicular crashes - biomed 2010.

Traffic safety has significantly improved over the past several decades reducing injury and fatality rates. However, there is a paucity of research effort directed to address the safety issues in off-highway vehicular crashes, specifically the all terrain/utility vehicular crashes. Rollover crashes are severe accidents leading to the increase in fatalities and injuries. The appropriate safety measures to contain occupants in vehicular compartments are crucial in mitigating injuries in rollover crashes. The purpose of this study is to delineate the occupant kinematics in simulated rollover conditions and to evaluate the injury prevention aspects. Two utility/all terrain vehicles were used. Each vehicle was placed on the motorized test equipment in the laboratory. The motorized dynamic rollover test equipment simulated the rollover environment in a controlled manner. Human surrogate models representing 1th percentile female, 50th percentile male and 96th percentile male were utilized in the testing. The multi-phase dynamic testing was conducted to quantify the occupant kinematic responses in foreseeable real world conditions. A total of 39 tests were conducted. The vehicle with belted surrogates was rolled 90 degrees at a roll rate up to 45 degrees/second. The excursion of the head, upper extremity and lower extremities beyond the plane of the vehicular structure was measured and compared between the two vehicles using two onboard cameras and three off-board cameras. Results show that the advanced restraint system with the occupant containment feature significantly reduced the occupant excursion. Such a significant reduction of occupant movement will better protect occupants in rollover off-highway accidents.

Real-time fluorescent quantitative polymerase chain reaction study of polo-like kinase-1 in pterygia.

This study was designed to examine the expression of polo-like kinase 1 (PLK1) mRNA in 16 pterygia and 13 normal conjunctival tissue specimens using real-time fluorescent quantitative polymerase chain reaction (PCR). Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as the housekeeping gene. The difference in threshold cycle value (DeltaC(t)) was derived for PLK1 and GAPDH for each sample assayed, and the difference between the paired samples (DeltaDeltaC(t)) was calculated. The mean +/- SD DeltaC(t) of PLK1 mRNA was 9.56 +/- 1.30 in pterygia compared with 10.71 +/- 1.39 in normal conjunctiva. The expression of PLK1 mRNA in pterygium was 2.08 - 2.36 times that in normal conjunctiva; this difference was statistically significant. Real-time fluorescent quantitative PCR analysis appears to be effective and sensitive when determining the level of PLK1 mRNA expression. Using this method, it was demonstrated that PLK1 mRNA is over-expressed in pterygia, indicating a probable role for PLK1 in their development.

A novel mutation in CRYBB2 responsible for inherited coronary cataract.

PURPOSE: To study the molecular pathogenesis of a Chinese family with coronary form of cataract. METHODS: One Chinese three-generation family with inherited coronary cataract phenotype was recruited. Five affected and seven unaffected family members attended our study. Genome-wide linkage analysis was applied to map the disease loci, and two candidate genes from a locus on chromosome 1 and a locus on chromosome 22 were sequenced for mutation identification. Software at the Expasy proteomics server was utilized to predict the mutation effect on proteins. RESULTS: Whole genome linkage analysis indicated some regions on chromosome 1, 10, and 22, with LOD score values greater than 1. Within these loci, the GJA8 and CRYBB2 genes, located in the two loci with the highest LOD score of 1.51 on chromosomes 1 and 22, respectively, were sequenced. A novel mutation c.92C>G in exon 2 of CRYBB2 causing S31W was identified in all five patients. It was not found in 95 unrelated controls. This missense sequence alteration likely enhanced the local solubility. Around the mutation site, a lipocalin signature motif was predicted by ScanProsite. CONCLUSIONS: A novel disease-causing mutation S31W in CRYBB2 was identified in a Chinese cataract family. It is the first reported mutation for coronary cataract. Functional characterization should be carried out to evaluate the biological effects of this mutant.

An assessment of exposure indices in computed radiography for the posterior-anterior chest and the lateral lumbar spine.

Studies have indicated that computed radiography (CR) can increase radiation dose to the patient, leading to potential biological effects. Although manufacturers have set parameters to safeguard against overexposure, it is unclear whether these are being used by radiographers or if their recommended values are consistent with the ALARA principle. The research aims are to investigate (i) whether radiographers are producing images with exposure indices within the manufacturers recommended range (MRR); (ii) the phenomenon of exposure creep, and (iii) the relationship between exposure indices (EIs) and radiation dose. A retrospective analysis of exposure indices over an 18-month period for the posteroanterior (PA) chest and lateral (LAT) lumbar spine at two centres using Kodak 800 and 850 CR systems was conducted. A phantom study was performed to assess the relationship between EI and entrance surface dose (ESD) for fixed and varying tube potentials. Kodak recommends that images have EIs between 1700 and 1900. Thirty percent of LAT lumbar spine examinations at hospital B and 38% of PA chest examinations at hospital A were produced with EIs below 1700. In the phantom study, when using a varied tube potential (70-125 kVp) and maintaining a constant EI of 1550, ESD was reduced by 56%. All clinical and phantom images were assessed to be of a diagnostic quality. The retrospective results indicate that there is a potential to reduce the MRR and optimize patient dose. There is also evidence to suggest that EI is not a reliable indicator of patient dose. The authors recommend that staff training is essential on these newer systems.

UVB 311 nm tolerance of vitiligo skin increases with skin photo type.

It is assumed that skin is protected against sunburn by melanin. In patients with vitiligo, there are white patches in the normal pigmented skin. We noticed that there is a difference in burning capacity of these white patches between people with different skin types. With UVB 311 nm lamps, we irradiated both lesional and non-lesional skin with increasing doses in 33 patients with vitiligo, divided into 5 groups according to skin type (II-VI). Twenty-four hours later we assessed the minimal erythema dose and found a correlation between skin type and UV sensitivity in both lesional skin and normal skin. We suggest that there must be a protection mechanism, other than that offered by melanin pigmentation. The antioxidant status may play a role in this phenomenon.

The tuberous sclerosis 2 gene product can localize to nuclei in a phosphorylation-dependent manner.

The tuberous sclerosis 2 (TSC2) gene has been genetically mapped to a disease characterized by abnormal cell proliferation that results in the production of tumorous lesions in a variety of tissues. The molecular mechanism for TSC2 mediation of tuberous sclerosis is unclear but it appears to be related to its ability to cytoplasmically interact with a second gene, TSC1, mapping to the disease. These proteins are linked to constraints on cell cycle signaling pathways and therefore envisioned to function as tumor suppressor genes. In previous studies we have demonstrated TSC2 associations with steroid receptor family members and modulation of their gene expression capabilities. Here we provide evidence for TSC2 translocation to the nucleus and a possible role for phosphorylation in both TSC2 translocation and TSC2 modulation of steroid receptor-mediated transcription.

Stimulation of antiviral antibody response in SHIV-IIIB-infected macaques.

Three macaques infected with SHIV-IIIB and expressing the shared 1F7-idiotypic marker on antibodies against HIV-1 gp120, were injected intravenously with 1F7 monoclonal antibodies (MoAb). As controls, a SHIV-IIIB-infected macaque was injected with a HIV-unrelated mouse monoclonal isotype antibody (TEPC-183) and two healthy, noninfected macaques were injected with MoAb 1F7. 1F7-id-expressing antibodies against gp120-IIIB decreased in two of the three MoAb 1F7-treated macaques and then rebounded. Importantly, antibodies binding to envelope proteins of heterologous HIV-1 strains MN, CM, and SF2, which were low or not detectable before the MoAb 1F7 treatment, increased rapidly following MoAb inoculations in all three 1F7 MoAb treated macaques, but not in the macaque injected with control MoAb TEPC-183. Newly arising antibodies reacting with heterologous virus, i.e. HIV-1 gp120-MN, SF2, and CM did not express 1F7-id. Surprisingly, significant increases of antibodies were also observed in the 1F7-inoculated macaques' antibodies directed to non-HIV antigens (DNP, peptides and BSA). The noninfected control animals did not produce antibodies to these antigens despite MoAb 1F7 treatment. These data show that the MoAb 1F7 injections of chronically SHIV-IIIB-infected macaques resulted in idiotype-specific clonal suppression with broadening the antibody response to HIV envelope proteins.

Dna fragmentation factor 45 mutant mice exhibit resistance to kainic acid-induced neuronal cell death.

Excitotoxicity is a process where glutamate or other excitatory amino acids induce neuronal cell death. Emerging evidence suggests that apoptosis plays a key part in excitotoxic neurodegeneration. The DNA fragmentation factor 45 (DFF45 or ICAD) is a subunit of a heterodimeric DNase complex crucial for DNA fragmentation during apoptosis. Using a DFF45 mutant mouse model, we previously found that DFF45 deficient cells are more resistant to apoptosis than normal control cells. To investigate whether the lack of DFF45 may attenuate neuronal cell death induced by excitotoxicity, we compared kainic acid-induced seizure behavior and neuronal cell death in DFF45 mutant and wild-type control mice. We found that the mutant mice exhibit similar kainic acid-induced seizure severity compared to control mice. However, DFF45 mutant mice are more resistant than control mice to kainic acid-induced CA3 neuronal cell death. Interestingly, residual DNA degradation can be detected in the hippocampus of DFF45 mutant mice that exhibit KA-induced lesions. Our results suggest that a lack of DFF45 can lead to neuronal resistance to excessive activity-induced toxicity.

Chemical engineering of cell penetrating antibodies.

Antibodies, being exquisitely specific tools in biology, are routinely used to detect and identify intra-cellular structures. However, current intra-cellular application of antibodies requires that the membrane be rendered leaky, resulting in the death of cells. Here, we present a novel method to allow antibodies to penetrate the cellular membrane of living cells without affecting cell viability. A peptide (MTS, membrane transport sequence) that facilitates transport across membranes has been site-specifically attached to antibodies. MTS-antibodies enter the living cells in culture and can be detected by immunofluorescence and ELISA after extraction. Cellular structures are visualized in living cells using a specific MTS-antibody. Antibodies with membrane penetrating properties can become an important tool for the study of intra-cellular processes in living cells. Furthermore, such membrane penetrating antibodies can be used to selectively stimulate or suppress functions of the cellular machinery.

Site-specific photobiotinylation of antibodies, light chains, and immunoglobulin fragments.

The high affinity of biotin for avidin has been exploited for many antibody-based assays. This requires that biotin is covalently conjugated to the antibody molecule. Several chemically reactive biotinylation reagents are commercially available. Except for the attachment via sulfhydryl groups in the immunoglobulin (Ig) molecule, these reagents attach biotin randomly to various amino acid side chains. Although non-site-specific modification of antibodies does not interfere in most immunoassays, specific application and sensitive antibodies would benefit from site-specific biotinylation. Here we describe an affinity biotinylation technique based on a photoreactive biotin reagent. The design of this reaction was possible from the discovery of a conserved binding site in the variable Ig domain for nucleotides and nucleosides. The described photoaffinity biotinylation offers the advantages of ease, convenience, and production of a reproducible and defined biotinylated antibody preparation.

Lack of obvious 50 kilobase pair DNA fragments in DNA fragmentation factor 45-deficient thymocytes upon activation of apoptosis.

The DNA fragmentation factor 45 (DFF45/ICAD) is a key subunit of a heterodimeric DNase complex critical for the induction of DNA fragmentation during apoptosis in vivo. To further assess the importance of DFF45 in chromosomal DNA degradation, we induced apoptosis in wild-type control and DFF45 deficient thymocytes and compared the cleavage of chromosomal DNA to 50 kilobase pair size fragments. We found that there is a lack of obvious large chromosomal DNA fragments upon treatments by various apoptotic agents in DFF45 deficient thymocytes. The major organ systems in the DFF45 mutant mice either two months or fifteen months of age appear normal. These results suggest that functional DFF45 is required for cleavage of DNA into both large size and oligonucleosomal size fragments in thymocytes during apoptosis. However, deficiency in DFF45 apparently does not significantly affect normal mouse development and tissue homeostasis.

Management of parapneumonic collections in infants and children.

BACKGROUND/PURPOSE: Video-assisted thoracoscopic surgery (VATS) has a recognized role in treatment of empyema thoracis. The purpose of this report is to show the value of initial VATS as the primary treatment of parapneumonic collections. METHODS: A retrospective review was done of 139 children who required surgical consultation for parapneumonic collections between January 1992 and July 1998. Management options were (M1) thoracentesis, chest tube drainage, or fibrinolytic therapy and delayed thoracotomy for unresolved collections; (M2) thoracentesis, chest tube drainage, fibrinolytic therapy with delayed VATS if the child remained ill; or (M3) primary VATS. Comparative data included age, duration of prehospital illness, oxygen requirements, white blood cell count, bacterial culture results, number of procedures performed per patient, duration of chest tube drainage, complications, and length of stay. Kruskal-Wallis 1-way analysis was used, with significance at P less than .05. RESULTS: A total of 60 children were treated by M1, 38 by M2, and 41 by M3. Age, duration of prehospital illness, oxygen requirements, white blood cell count, bacterial culture results, and complication rates were comparable. The median length of stay was 12 days for M1, 11 days for M2, and 7 days for M3, with M3 significantly shorter at P<.001. The number of procedures was a median of 2 in M1, 2 in M2, and 1 in M3, with M3 significantly fewer at P<.001. Duration of chest tube drainage was a median 5 days for M1 and 3 days for M2 and M3, with M1 significantly longer at P<.001. There were 9 thoracotomies in the M1 group, 3 in the M2 group, and none in the M3 group. One child in M3 required a second VATS. CONCLUSIONS: Primary VATS has significantly decreased the number of procedures, duration of chest tube drainage and length of stay for children with parapneumonic effusions. Primary VATS appears to be of value in management of bacterial pneumonia with effusion.

[The expression of connexin 43 and desmin in viral myocarditis].

OBJECTIVE: To study the cytobiological basis of constriction dysfunction and arrhythmia in cardiac muscle cells with viral myocarditis. METHODS: The expression of connexin 43 and desmin in cardiac muscle cells of mice with experimental viral myocarditis was determined by immunohistochemistry. RESULTS: In normal mice, connexin 43 and desmin are located in the intercalated disks of cardiac muscle, and the latter also revealed a positive immunoreactivity in the cross striations of sarcomeres. In viral myocarditis, the expression of both became much weakened, can even become negative. CONCLUSION: In myocarditis, expression of connexin 43 and desmin in the involved cardiac muscle cells was inhibited, resulting in dysfunction of gap junctional communication and arrhythmia.