Genetic relatedness among azole-resistant Candida tropicalis clinical strains in Taiwan from 2014 to 2018.

To monitor trends in the distribution of yeast species and the susceptibilities of these species to commonly prescribed antifungal drugs, we conduct the Taiwan Surveillance of Antimicrobial Resistance of Yeasts (TSARY) every 4 years. We found that 25 of 294 Candida tropicalis isolates from TSARY 2014 and 31 of 314 C. tropicalis isolates from TSARY 2018 were resistant to fluconazole. We determined the genetic relatedness among fluconazole-resistant C. tropicalis isolates by multilocus sequence typing (MLST). Among 174 C. tropicalis isolates, including all 56 fluconazole-resistant, all 26 susceptible-dose dependent and 92 selected fluconazole-susceptible isolates, 59 diploid sequence types (DSTs) were identified. We found that 22 of the 25 fluconazole-resistant C. tropicalis from TSARY 2014 and 29 of the 31 fluconazole-resistant C. tropicalis from TSARY 2018 were genetically related and belonged to the same cluster (clade 4). A combination of mutation and overexpression of ERG11, encoding the target of azole drugs, was the major mechanism contributing to drug resistance. Approximately two-thirds of reviewed patients infected or colonised by fluconazole-resistant C. tropicalis were azole-naïve. Furthermore, there was no evidence of patient-to-patient transmission. Because the clade 4 fluconazole-resistant C. tropicalis strain persists in Taiwan, it is important to identify the source of azole-resistant C. tropicalis to prevent the spread of this resistant strain.

A time-course study of microglial activation and dopaminergic neuron loss in the substantia nigra of mice with paraquat-induced Parkinson's disease.

Activated microglia play an active role in the pathogenesis of PD and paraquat (PQ) induces PD. The study was to understand the time relationship between microglial activation and dopaminergic neuron loss in the substantia nigra (SN) of PQ-induced PD mice. Male C57BL/6 mice were injected intraperitoneally with PQ, twice a week for six weeks. Some mice underwent behavioral assessments each week and were sacrificed for SN tissues, in which histopathological analysis, dopaminergic neuron loss, microglial activation and phenotypic characteristics were evaluated. The results showed that motor retardation, coordination disorders and limb stiffness occurred four weeks after PQ exposure, as well as the degeneration and loss of dopaminergic neurons in the SN. Activated microglia and increased CD68 expression appeared two weeks after PQ exposure in time-dependent manners. Increased CD86 and decreased CD206 expression were observed four weeks after PQ exposure, accompanied by increased TNF-α and IL-6 levels and decreased IL-10 and TGF-ß levels. These results indicate that PQ can activate microglia in vivo, and microglial activation precedes neuronal loss in the SN. Activated microglia are characterized by mixed M1/M2 polarization in the early stage and M1 polarization in the late stage of PQ-induced PD development.

Recombinant Newcastle disease virus (NDV) La Sota expressing the haemagglutinin-neuraminidase protein of genotype VII NDV shows improved protection efficacy against NDV challenge.

Intensive vaccination strategies against Newcastle disease (ND) have been implemented in many countries for a long time, but ND outbreaks still occur frequently, with most isolates belonging to genotype VII of Newcastle disease virus (NDV). Many researchers have revealed that vaccines closely matched to epidemic viruses provide better protection. Therefore, using a previously established reverse genetics system, we generated a recombinant NDV vaccine strain (rLa Sota-HN) based on the La Sota vaccine strain expressing the haemagglutinin-neuraminidase (HN) protein of genotype VII NDV. The pathogenicity of the recombinant virus was confirmed by the mean death time in 9-day-old specific-pathogen-free embryonated chicken eggs and the intracerebral pathogenicity index in 1-day-old specific-pathogen-free chickens. Subsequently, 1-day-old chickens were immunized with commercial vaccine La Sota and recombinant virus rLa Sota-HN and then challenged with virulent genotype VII NDV strain. The results indicated that recombinant virus rLa Sota-HN provided increased protection of vaccinated chickens from morbidity and mortality, and inhibited the shedding of virulent virus after challenging with genotype VII virus, compared with the conventional vaccine La Sota. Our findings indicated that rLa Sota-HN is a promising vaccine candidate to improve the protection efficiency against ND in chickens, thereby preventing frequent outbreaks of this disease.

Recombinant Fiber-2 Protein-Based Indirect ELISA for Antibody Detection of Fowl Adenovirus Serotype 4.

Clinical cases of hepatitis-hydropericardium syndrome (HHS) from fowl adenovirus serotype 4 (FAdV-4) have increased in China since 2013. Therefore, the development of a new serologic method for HHS detection is now urgent. Here, the FAdV-4 strain JSJ13 was used to construct a plasmid for prokaryotic expression of the JSJ13 fiber-2 protein. The protein, purified by affinity chromatography, was refolded by gradient dialysis. After coating a 96-well plate with the purified fiber-2 protein (1.5 µg/ml), standard serum and secondary antibodies (1:200 and 1:6000 dilutions, respectively) were used to develop an indirect ELISA (I-ELISA). Nine field-collected serum samples and JSJ13-positive serum were tested by I-ELISA and the results corresponded with those of the serum neutralization test. The I-ELISA was used to test 450 clinical serum samples from different parts of China. Chickens from nonvaccinated flocks had low antibody titers and low virus positivity rates. In contrast, FAdV-4 vaccinated chickens were strongly positive, and the positivity rates of all the flocks exceeded 73.3%. The newly developed I-ELISA with the recombinant JSJ13 fiber-2 protein as the antigen detected antibodies to FAdV-4 accurately and sensitively.

Different Origins of Newcastle Disease Virus Hemagglutinin-Neuraminidase Protein Modulate the Replication Efficiency and Pathogenicity of the Virus.

To investigate the exact effects of different origins of Newcastle disease virus (NDV) hemagglutinin-neuraminidase (HN) protein to the biological characteristics of the virus, we systematically studied the correlation between the HN protein and NDV virulence by exchanging the HN of velogenic or lentogenic NDV strains with the HN from other strains of different virulence. The results revealed that the rSG10 or rLaSota derivatives bearing the HN gene of other viruses exhibited decreased or increased hemadsorption (HAd), neuraminidase and fusion promotion activities. In vitro and in vivo tests further showed that changes in replication level, tissue tropism and virulence of the chimeric viruses were also consistent with these biological activities. These findings demonstrated that the balance among three biological activities caused variation in replication and pathogenicity of the virus, which was closely related to the origin of the HN protein. Our study highlights the importance of the HN glycoprotein in modulating the virulence of NDV and contributes to a more complete understanding of the virulence of NDV.

Microglial Activation in the Pathogenesis of Huntington's Disease.

Huntington's disease (HD) is an autosomal dominantly inherited neurodegenerative disorder caused by expanded CAG trinucleotide repeats (>36) in exon 1 of HTT gene that encodes huntingtin protein. Although HD is characterized by a predominant loss of neurons in the striatum and cortex, previous studies point to a critical role of aberrant accumulation of mutant huntingtin in microglia that contributes to the progressive neurodegeneration in HD, through both cell-autonomous and non-cell-autonomous mechanisms. Microglia are resident immune cells in the central nervous system (CNS), which function to surveil the microenvironment at a quiescent state. In response to various pro-inflammatory stimuli, microglia become activated and undergo two separate phases (M1 and M2 phenotype), which release pro-inflammatory cytokines (IL-1ß, IL-6, and TNF-α), anti-inflammatory cytokines, and growth factors (TGF-ß, CD206, and Arg1), respectively. Immunoregulation by microglial activation could be either neurotoxic or neuroprotective. In this review, we summarized current understanding about microglial activation in the pathogenesis and progression of HD, with a primary focus of M1 and M2 phenotype of activated microglia and their corresponding signaling pathways.

Effect of interleukin-1ß and lipoxin A4 in human endometriotic stromal cells: Proteomic analysis.

AIM: Lipoxin A4 (LXA4 ) can function as an endogenous 'breaking signal' in inflammation and plays an important role in the progression of endometriosis. The proteome responses to interleukin-1ß (IL-1ß) or LXA4 in human endometriotic stromal cells (ESC) are not well understood. METHODS: In this study, primary ESC were cultured from ovarian endometriosis tissue. Three groups were established: the control group; the IL-1ß stimulation group; and the IL-1ß and LXA4 incubation group. Proteins were assessed on 2-D polyacrylamide gel electrophoresis (2D-PAGE), and differentially expressed protein spots were further identified on matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry (MALDI-TOF-MS). Wound healing and transwell assays were performed to assess the migration and invasion of ESC after treatment. RESULTS: In total, 40 differentially expressed protein spots were identified successfully on MALDI-TOF-MS. The proteins identified were related to cell structure, metabolism, signal transduction, protein synthesis and membrane structure, processes that may be involved in the development of endometriosis. Vinculin and IL-4 were further analyzed on western blot and quantitative real-time polymerase chain reaction. Moreover, LXA4 could suppress the migration and invasion of ESC induced by IL-1ß. CONCLUSION: LXA4 may inhibit the progression of endometriosis partly by lowering or raising the effect of IL-1ß, mediated via some inflammation-related proteins (e.g. vinculin) and immune response-related protein (e.g. IL-4) in vitro.

Antigenic variation of LaSota and genotype VII Newcastle disease virus (NDV) and their efficacy against challenge with velogenic NDV.

Continued monitoring and evaluation of vaccine efficacy against prevalent or newly isolated strains has great importance in advising Newcastle disease (ND) immunization strategy. In this study, we systematically analysed the antigenic variation between genotype VII NDV aSG10 and the commercial vaccine strain LaSota, and assessed their efficacy against challenge with velogenic NDV by serological analysis and animal testing. We show that these two viruses are antigenically distinguishable; anti-NDV aSG10 hyper-immune sera demonstrated higher haemagglutination inhibition (HI) titres (11.13±0.30log2) against the aSG10 virus, compared with titres against LaSota (9.53±0.50log2). Conversely, the hyper-immune sera from LaSota showed higher HI titres against LaSota virus (9.73±0.36log2), but 2-fold lower HI titre against aSG10 (8.87±0.38log2). Each serum neutralised heterologous virus, but neutralisation titres were always 3- to 6-fold higher against its homologous strain than heterologous virus. The cross-reactivity R value between aSG10 and LaSota was 0.23, indicating that they are loosely related with major antigenic differences within a single serotype. The results of animal tests revealed that the aSG10 vaccine had a significantly higher protection rate than the LaSota vaccine against genotype VII NDV, regardless of intramuscular (IM) or eye drop/intranasal (ED/IN) route of SG10 challenge. Compared with IM administration, chicken flocks needed higher HI antibody levels to obtain sufficient protection when challenged by the natural ED/IN route. These results are highly informative for better control of ND in the poultry industry.

Multi-dimensional analysis on Parkinson's disease questionnaire-39 in Parkinson's patients treated with Bushen Huoxue Granule: A multicenter, randomized, double-blinded and placebo controlled trial.

OBJECTIVES: To preliminarily assess the effects of Bushen Huoxue Granule (BHG) on Parkinson's Patients with Parkinson's Disease Questionnaire-39 (PDQ-39)and to provide data for further research. DESIGN: A randomized, double-blinded, placebo controlled study with a 3-month intervention period and a 6-month follow-up. INTERVENTIONS: Participants were patients with Parkinson's Disease (PD) of age ranging from 50 to 80 years and Hoehn and Yahr (H-Y) stage I-IV of the disease.120 participants were allocated to BHG group or placebo group at a 1:1 ratio. The BHG group received BHG twice a day for 3 months, and was followed-up for 6 months after treatment; the placebo group did not receive any Chinese Herb treatment for 9 months. All the patients were given the conventional therapy of levodopa (Madopar). MAIN OUTCOME MEASURES: Primary outcome measure was PDQ-39 comprises 39 questions with five different options of answer related to the frequency of the disease manifestation. RESULTS: Significant statistical difference appeared in the following PDQ-39 dimensions: mobility; emotional well-being; stigma; cognition (P<0.01) and bodily discomfort (P<0.05).There was no statistical difference in the dimensions of social support, ADL and communication between the data of these two group patients (P≥0.05). We found that the sum index of PDQ-39 was significantly different between two groups. CONCLUSION: The results of this study show that BHG treatment makes significant effects in most domains of PD patients life quality,especially in mobility, emotional well-being, stigma and cognition. The affected factors should be confirmed in larger studies.

Pharmacological Effects of Active Components of Chinese Herbal Medicine in the Treatment of Alzheimer's Disease: A Review.

Alzheimer's disease (AD), the most common neurodegenerative disorder associated with dementia, not only severely decreases the quality of life for its victims, but also brings a heavy economic burden to the family and society. Unfortunately, few chemical drugs designed for clinical applications have reached the expected preventive or therapeutic effect so far, and combined with their significant side-effects, there is therefore an urgent need for new strategies to be developed for AD treatment. Traditional Chinese Medicine has accumulated many experiences in the treatment of dementia during thousands of years of practice; modern pharmacological studies have confirmed the therapeutic effects of many active components derived from Chinese herbal medicines (CHM). Ginsenoside Rg1, extracted from Radix Ginseng, exerts a [Formula: see text]-secretase inhibitor effect so as to decrease A[Formula: see text] aggregation. It can also inhibit the apoptosis of neuron cells. Tanshinone IIA, extracted from Radix Salviae miltiorrhizae, and baicalin, extracted from Radix Scutellariae[Formula: see text] can inhibit the oxidative stress injury in neuronal cells. Icariin, extracted from Epimedium brevicornum, can decrease A[Formula: see text] levels and the hyperphosphorylation of tau protein, and can also inhibit oxidative stress and apoptosis. Huperzine A, extracted from Huperzia serrata, exerts a cholinesterase inhibitor effect. Evodiamine, extracted from Fructus Evodiae, and curcumin, extracted from Rhizoma Curcumae Longae, exert anti-inflammatory actions. Curcumin can act on A[Formula: see text] and tau too. Due to the advantages of multi-target effects and fewer side effects, Chinese medicine is more appropriate for long-term use. In this present review, the pharmacological effects of commonly used active components derived from Chinese herbal medicines in the treatment of AD are discussed.

[Factors influencing the bone mineral density in preterm infants].

OBJECTIVE: To study the bone mineral development and the factors influencing the development in preterm infants. METHODS: Ninety preterm and 90 term infants followed up by the child health care service were randomly enrolled. Tibia quantitative ultrasound measurements were used to evaluate bone mineral density described as supersonic speed of sound (SOS) and Z scores at 6 months old (corrected gestational age for preterm infants). The factors influencing bone mineral development were investigated by questionnaire. RESULTS: The SOS values and Z scores in term infants were significantly higher than those in preterm infants at 6 months old. In the preterm group, the SOS values and Z scores were significantly different in infants with different birth weights or gestational ages (P<0.05). The SOS values in preterm infants with different weaning time were significantly different. The Z scores in female preterm infants were significantly higher than that in males (P<0.05). Multiple regression analysis indicated that weaning time and daily time of outdoor activities were independent factors influencing SOS values in preterm infants. CONCLUSIONS: It is helpful to promote bone mineral development by an appropriate weaning time or increasing the time of outdoor activities in preterm infants.

SB203580, a p38 mitogen-activated protein kinase inhibitor, suppresses the development of endometriosis by down-regulating proinflammatory cytokines and proteolytic factors in a mouse model.

BACKGROUND: p38 mitogen-activated protein kinase (p38 MAPK), a regulator of inflammation, may play a role in the pathogenesis of endometriosis (EM). We studied the effect of SB203580, a p38 MAPK inhibitor, on the development of EM in a mouse model. METHODS: EM was induced in BALB/c mice by peritoneal injection of endometrium-rich fragments. Mice (n = 15) were injected i.p. for 24 days with SB203580 and 15 mice served as positive controls (EM group). Sham-operated mice received carrier only. Peritoneal fluid (PF) cells were collected for protein/mRNA analysis. Interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, matrix metalloproteinase-2 (MMP-2) and MMP-9 proteins were measured using enzyme-linked immunosorbent assay and mRNAs by RT-PCR. Phosphorylation of p38 MAPK was evaluated by western blotting. RESULTS: SB203580 decreased the weight and size (P < 0.05 versus EM) of endometriotic lesions in BALB/c mice. IL-1ß, TNF-α, MMP-2 and MMP-9 mRNA levels were decreased in peritoneal cells of the SB203580 versus EM group (P < 0.01, P < 0.05, P < 0.05 and P < 0.05, respectively). Concentrations of IL-1ß, TNF-α, MMP-2 and MMP-9 proteins in PF were reduced in the SB203580 versus EM group (P < 0.05, P < 0.01, P < 0.05 and P < 0.05, respectively). Compared with the sham-operated group, phosphorylation of p38 MAPK in the EM group was increased, and this was down-regulated by SB203580 (P < 0.01). CONCLUSIONS: SB203580 may suppress the development of EM by inhibiting expression of proinflammatory cytokines and proteolytic factors. p38 MAPK might play a key role in progression of EM.

[Meta analysis of lactic acid bacteria as probiotics for the primary prevention of infantile eczema].

OBJECTIVE: To determine whether lactic acid bacteria as probiotics is efficacious in the primary prevention of infantile eczema or atopic eczema. METHODS: For this meta analysis of randomized controlled trials (RCT) describing the efficacy of probiotics in infants with eczema or atopic eczema at ages of ≤2 years, a comprehensive search in the databases was performed up to January 2010. Three reviewers independently evaluated the studies for methodological qualities. RevMan 5.0.2 software was used for meta analysis. RESULTS: Twelve RCTs on the preventive effects of lactic acid bacteria as probiotics on infantile eczema were included, and 7 of the 12 RCTs reported the preventive effect of lactic acid bacteria on atopic eczema. The meta analysis showed that there was an overall significant reduction in infantile eczema and atopic eczema favoring lactic acid bacteria compared with placebo. The relative risk (RR) ratios for eczema and atopic eczema were 0.80 (95%CI: 0.70-0.90; P<0.01) and 0.78 (95%CI: 0.64-0.97; P<0.01), respectively. Lactic acid bacteria combined with other probiotics decreased significantly the incidence of eczema, with a RR ratio of 0.79 (95%CI: 0.68-0.93; P<0.01). The use of lactic acid bacteria alone did not result in a reduction in the incidence of eczema, with a RR ratio of 0.85 (95%CI: 0.69-1.05; P>0.05). CONCLUSIONS: The data from this meta analysis suggest that lactic acid probiotics combined with other probiotics play a role in the prevention of infantile eczema. There is insufficient evidence to recommend single use of lactic acid bacteria for prevention of eczema. Further studies are required to determine whether the findings are reproducible.

High prevalence of vitamin D and calcium deficiency among pregnant women and their newborns in Chengdu, China.

BACKGROUND: Vitamin D and calcium deficiency is common in pregnant women and newborn infants. There are few data about the prevalence of hypovitaminosis D during pregnancy and infancy in China. We assessed vitamin D status of pregnant women and their neonates in Chengdu, Sichuan province, China. METHODS: Maternal serum and cord blood levels of calcium, 25-hydroxyvitamin D [25(OH)D], alkaline phosphatase, and parathyroid hormone (PTH) were studied in 77 urban and rural mother-neonate pairs at term. RESULTS: The mean level of maternal serum 25(OH)D was 35.95+/-19.7 nmol/L, and that of cord blood 25(OH)D was 40.98+/-18.89 nmol/L. The intake of calcium and vitamin D was uniformly low, although it was higher in urban (1010+/-450 mg/d, 237+/-169 IU/d) than in rural (320+/-210 mg/d, 62+/-66 IU/d) women. Maternal serum 25(OH)D was correlated positively with cord blood 25(OH)D (r=0.94, P<0.01). CONCLUSIONS: There is a high prevalence of vitamin D and calcium insufficiency in pregnant women and neonates in Chengdu even when mothers are compliant with prenatal vitamin supplementation. Supplementation is needed to improve maternal and neonatal vitamin D and calcium nutrition.

[Relationship between Ghrelin and growth hormone secretagogue receptor expression and catch-up growth in rats with intrauterine growth restriction].

OBJECTIVE: To study the relationship between Ghrelin and growth hormone secretagogue receptor (GHSR) expression and the catch-up growth in rats with intrauterine growth restriction (IUGR). METHODS: The rat model of IUGR was established by food restriction during pregnancy. The small for gestational age (SGA) and appropriate for gestational age (AGA) rat pups from the pregnant rats were used as the experimental group. The AGA rat pups from the pregnant rats without food restriction served as the control group. The samples from the stomach fundus and hypothalamus were taken postnatal days 0, 20 and 40. Ghrelin mRNA and GHSR mRNA expression were determined by real-time fluorescence quantitative PCR (real-time FQ-PCR). Ghrelin protein and GHSR protein expression were examined by immunohistochemistry (IHC). RESULTS: At postnatal day 0, both Gherlin mRNA and protein levels in the stomach fundus were significantly higher, while GHSR mRNA expression in the hypothalamus were significantly lower in SGA rats from food restriction group than those in AGA rats from restriction and control groups. At postnatal day 20, the ghrelin protein expression in the stomach of fundus, and GHSR mRNA and protein expression in the hypothalamus in SGA catch-up rats were significantly higher than those in SGA non-catch-up growth rats and AGA rats from the control group. At postnatal day 40, there were no significant differences among SGA catch-up growth rats, SGA non-catch-up growth rats and normal AGA rats. CONCLUSIONS: Ghrelin-GHSR might be involved in the physiological regulation and pathological process in IUGR rats. It is also possibly involved in the regulation of catch-up growth in the early life of SGA rats.

[Effects of different feeding types on the physical growth of infants].

OBJECTIVE: To investigate the effects of different feeding types on the physical growth of infants. METHODS: Infants who visited the children health clinics regularly were recruited for the study. They were classified into breast feeding group, bottle feeding group and mixed feeding group according to the feeding types before 4-months-old. The growth indices were measured and the WHO BMI standards were used to identify overweight and obesity. RESULTS: The body weights and lengths of the male infants with breast feeding were greater than those with other feedings in the first 3 months. The growth of the male infants with bottle feeding began to exceed the other two groups gradually from the 4 month on. The differences of weight and height are statistically significant from 10-12 month and 8-12 month respectively, compared with breast feeding group. The body weights of the female infants with bottle feeding were greater than those with other feedings except for the first month, and the differences were statistically significant from 3 to 12 month (P<0.05). The body lengths of the female infants with bottle feeding were also greater than those with other feedings except for the first two months, and the differences were statistically significant from 4 to 12 month (P<0.05). Before 3-months-old, overweight was more prevalent in the infants with breast feeding than the others. But for the infants 4-months-old and over, overweight was most prevalent in those with bottle feeding (P<0.05). The obesity rate was the highest in the infants with bottle feeding except for the 2-months-old (P<0.05). CONCLUSION: The infants with bottle feeding are exposed to a higher risk of overweight and obesity. Breast feeding may have a potential benefit in preventing infant obesity.

[Sleep problems among school age children in Chengdu].

OBJECTIVE: To identify the sleep patterns and sleep problems in the children of school age in Chengdu. Methods In 2005, 2848 children of school age were randomly selected from five districts in Chengdu to participants in a questionnaire survey. The sleep behaviors of the participants and their determinants were investigated. RESULTS: The sleeping time decreased with age (P<0.05). More than half of the participants (58.08%) had sleep disorders, which included enuresis (5.65%), sleeptalking (16.15%), sleepinquietude (34.34%), sleepwalking (2.84%), bruxism (22.86%), snoring (10.92%), sleep apnoea (0.77%), decompensation (3.12%), and nightmares (11.76%). The boys had greater prevalence of sleepwalking and snoring than the girls. There was a significant age difference for sleepinquietude and bruxism. The factors that had an impact on the sleep disorders included: after school classes, neuro-medication and foods, exciting activities, depressive moods of mothers or caregivers, and allergic reactions to medicines and foods. CONCLUSION: Sleep deprivations and high prevalence of sleep disorders among the school age children in Chengdu need to be addressed.

Neurogranin expression in stably transfected N2A cell line affects cytosolic calcium level by nitric oxide stimulation.

To test a cellular effect of rodent neurogranin (Ng) oxidation as compared to Ng phosphorylation, we develop a cell model capable of stable expression of Ng using the Tet-On system, and determine whether Ng oxidation regulates intracellular calcium level. Our results show that Ng oxidation by nitric oxide donor induces an increase of [Ca(2+)](i) in Ng-expressed cells as compared to the control cells without expressing Ng. These results suggest that Ng oxidation plays a significant role in intracellular Ca(2+) homeostasis, essential for the activated signaling networks in learning and memory.

[Injury of myocardial mitochondria in neonatal swines with hypoxic-ischemic brain damage].

OBJECTIVE: To clarify the effect of hypoxia and ischemia on the concentration of Ca2+ in myocardial mitochondria, and on the activity of respiratory chain complex IV--cytochrome oxidase (CCO) in neonatal swines, and to find out the change of myocardial mitochondria during hypoxic-ischemic brain damage (HIBD). METHODS: The study was performed on neonatal swines. For establishment of HIBD model, the left carotid was ligated and the swine was placed under hypoxia for two hours. Then the concentration of Ca2+ and the activity of respiratory chain complex IV in myocardial cell mitochondria were measured at 0 hour and 24, 48, 72 hours after reoxygenation. The measured values from these 0-, 24-, 48-, 72-hour-HIBD-groups (n = 10 per group) and from the normal control group (n = 10) were statistically analyzed by means of ANOVA, Newman-Keuls test and linear correlation. RESULTS: After the swines were placed under hypoxia-ischemia for two hours, 1. the concentration of Ca2+ in myocardial mitochondria increased, till 24 hours after re-oxygenation, and then it descended at 48 hours and 72 hours after reoxygenation; 2. the activity of myocardial mitochondrial respiratory chain complex IV descended, though activity recovery was seen at 48 and 72 hours, it did not come back to normal level at 72 hours after reoxygenation; 3. the concentration of Ca2+ in myocardial mitochondria was negatively correlated with the activity of respiratory chain complex IV. CONCLUSION: The results showed that in the neonatal swines with HIBD, the mitochondrial respiratory chain in myocardial cell was damaged by hypoxia-ischemia, yet it could be rehabilitated after reoxygenation. Calcium overload in myocardial mitochondria after hypoxia-ischemia might be one of the causes of the descending activity of respiratory chain complex IV.