[Pathogenic characteristics of viral diarrhea in children under five years of age in sentinel surveillance in Lulong County of Hebei Province, 2010-2020]

Objective: To analyze pathogenic characteristics of viral diarrhea in children aged <5 years in Hebei Province and provide reference for the prevention and control of viral diarrhea in children. Methods: Stool samples were collected from in-patients with diarrhea under five years old from sentinel hospitals in Lulong County of Hebei between 2010 and 2020. ELISA detected rotavirus antigen, and then positive samples were genotyped by semi nested reverse transcription PCR of two rounds. Calicivirus, genotyping astrovirus, and adenovirus were detected by real-time fluorescence quantification PCR. The data were analyzed by using software SPSS 20.0. Results: In 2 925 detected stool samples, 1 919 (65.61%) were positive. The positive rates of rotavirus, calicivirus, adenovirus, and astrovirus were 42.80% (1 252/2 925), 22.12% (647/2 925), 6.19% (181/2 925), 3.56% (104/2 925). Viral diarrhea was mainly caused by rotavirus infection, accounting for 59.30% (1 017/1 715) between 2010 and 2017, and by calicivirus infection accounting for 53.43% (109/204) between 2018 and 2020. The peak positive rate of rotavirus occurred in winter, with the highest rate in infants aged 12 to 17 months (52.96%,483/912). In the rotavirus positive samples, G9P[8] was mainly detected strains (58.31%,730/1 252), followed by G3P[8] (8.15%,102/1 252). The calicivirus-positive samples were mainly infected with norovirus GⅡ. Sequence analysis indicated that the main type was GⅡ.4 [P31] between 2011 and 2016 and GⅡ.3 [P12] in 2018. Conclusions: Rotavirus and calicivirus were the main pathogens causing infant diarrhea in children under five years old in Hebei from 2010 to 2020. Winter was the main epidemic season.

Manual Reduction and Plaster External Fixation for the Treatment of Closed Total Talus Dislocation: Case Report and Literature Review

BACKGROUND

Total dislocation of the talus from all its surrounding joints (talonavicular, tibiotalar, subtalar) is one kind of serious injury of the lower extremity with rare occurrence. It is usually accompanied by fractures of the talus and its periphery, as well as severe soft tissue injury, which is difficult to reset. Complications such as skin necrosis and infection are prone to occur in the early stage, and talus necrosis are prone to occur in the late stage, all of which aggravate disease severity and increase difficulties for its treatment.

CASE PRESENTATION

Herein, we reported a case of right talus total dislocation accompanied by medial malleolus fracture and posterior tubercle fracture caused by traffic accident. One hour after injury, the doctor tried to perform manual reduction but failed. Then, we successfully performed manual reduction and plaster external fixation on this patient under anesthesia 6 h after injury, followed by the oral administration of Chinese medicine for 3 months. Twenty months of follow-up investigations revealed that no skin necrosis, talus dislocation, talus necrosis, or other complications occurred; no obvious joint degeneration was observed and the fractures of medial malleolus and talus healed well. MRI of ankle joint indicated the disappearance of ankle effusion caused by injury, and the bone marrow edema had also subsided at talus, medial malleolus, and lateral malleolus and calcaneus. Patient presented with no ligament relaxation, ankle instability, pain, swelling, or functional limitation of the injured limb. AOFAS score reached 100. Daily functions and recreation activities were recovered back to the normal level.

CONCLUSION

For patients with closed total dislocation of the talus, fine therapeutic effects can be achieved by early closed manual reduction and plaster external fixation under anesthesia, in combination with oral Chinese herbal medicine afterwards. It is worthy of reference for clinicians.

[Analysis on influence and lag effects of meteorological factors on incidence of hand, foot and mouth disease in Shijiazhuang, 2017-2019]

Objective: To understand the influence and lag effect of meteorological factors on the incidence of hand, foot and mouth disease (HFMD) in Shijiazhuang. Methods: The daily incidence data of HFMD in Shijiazhuang during 2017-2019 were collected from Chinese Information System for Disease Control and Prevention. The hourly meteorological data were collected form meteorological stations of Shijiazhuang of Chinese meteorological data network. The distributed lag nonlinear model was built for statistical analysis by software R 3.6.2. Results: When the daily average temperature was 15-26 ℃, the risk of incidence of HFMD increased at lag 3-6 days. However, the risk was highest when the temperature was 25 ℃ at lag 3 days (RR=1.03,95%CI:1.00-1.06). When the daily average relative humidity was more than 80%, the risk of incidence of HFMD increased at lag 5-18 days. However, the risk was highest at lag 9 days (RR=1.04, 95%CI: 1.02-1.06).When the daily average air pressure ranged from 999 hPa to 1 007 hPa, the risk of incidence of HFMD increased at lag 5-8 days. However, the risk was highest at lag 6 days (RR=1.01, 95%CI: 1.00-1.02).When the daily average precipitation ranged from 15 to 32 mm, the risk of incidence of HFMD increased at lag 3-18 days. However, the risk was highest at lag 6 days (RR=1.11, 95%CI: 1.02-1.19). Conclusions: Meteorological factors increased the risk of incidence of HFMD such as higher daily average temperature (15-26 ℃), higher daily average humidity (>80%), lower daily average air pressure (999-1 007 hPa) and higher daily average precipitation (15-32 mm) in Shijiazhuang during 2017-2019. They were all correlated with the incidence of HFMD with certain lag days. It is suggested to use these meteorological indicators for the early warning of HFMD.

[Epidemiological and pathogenic characteristics of cases with severe and fatal hand, foot, and mouth disease caused by other enterovirus in Hebei province, 2013-2017]

Objective: To understand the epidemiological characteristics of cases with severe and fatal hand, foot, and mouth disease (HFMD) caused by other enterovirus in Hebei province, 2013-2017. Genetic characteristics of the main pathogen cosackie virus A6 (CoxA6) were also analyzed to further clarifying the characteristics and rules of genetic evolution on this virus. Methods: Descriptive epidemiological methods were used to analyze the distribution of severe and fatal cases with HFMD caused by other enterovirus in Hebei, 2013-2017. The VP1 sequences of CoxA6 were phylogenetically analyzed, using the Mega 5.2 software package. Results: A total of 86 severe and fatal cases with HFMD caused by other enterovirus were reported, accounting for 1.12%, comparing to all the HFMD caused by other enterovirus. Cases began to rise in April, and peaked in May-July. 65.12% of the cases occurred in children between 1 and 5 years old. The sex ratio between male and female was 1.39∶1. A total of 93.02% of the cases were children outside the child care settings. A total of 39 positive strains were identified, with positive isolation rate as 45.35%. Phylogenetic analysis on the VP1 sequences of CoxA6 strains in this study revealed that CoxA6 strains belonged to sub-genotypes D3a and D3b. Conclusions: Severe and fatal HFMD cases that caused by other enterovirus in Hebei province was with seasonal feature, consistent with the overall trend of this disease, 2013-2017. No new evolutionary branch appeared in the CoxA6 strain.

[Analysis of cardiac troponin C gene TNNC1 c. G175C mutation in a Chinese pedigree with familial hypertrophic cardiomyopathy and the correlation between genotype and phenotype]

Objective: To investigate the genotype-phenotype correlation in Chinese familial hypertrophic cardiomyopathy (HCM )focusing on the cardiac troponin C gene TNNC1 c. G175C mutation. Methods: All family members of a Chinese pedigree with hypertrophic cardiomyopathy admitted in Third People's Hospital of Qingdao in February 2005 and 200 healthy volunteers were included in this study. The coding exons of 30 hypertrophic cardiomyopathy associated genes were identified by whole exons amplification and high-throughput sequencing in the proband, and the identified mutation were further detected through bi-directional Sanger sequencing in all family members and 200 healthy volunteers. Pedigree analysis included clinical manifestation, physical examination, ECG and echocardiogram. Results: A missense mutation c. G175C was identified in the TNNC1 gene in 2 family members, which resulted in a glutamic acid (E) to glutamine (Q) exchange at amino acid residue 59. A mutation c. A1319G was identified in the MYLK2 gene in 1 family member, which resulted in a lysine (K) to arginine (R) exchange at amino acid residue 440. These mutations were absent in 200 healthy controls. The proband carried the two kinds of mutations and expressed various clinical manifestations of heart failure and had history of ventricular tachycardia, paraxial atrial fibrillation, pacemaker implantation, electrocardiogram showed right bundle branch block and echocardiography examination evidenced thickened interventricular septum (23.3 mm) and apex and reduced wall motion of these segments. The daughter of the proband carried the TNNC1 c. G175C mutation and was also diagnosed with asymptomatic HCM by echocardiography with thickened interventricular septum (19 mm) and apex (15 mm). Conclusion: The novel missense mutation of TNNC1 c. G175C might be the disease-causing gene mutation in this Chinese pedigree with familiar HCM.

Adrenoceptor blockade alters plasma gelatinase activity in patients with heart failure and MMP-9 promoter activity in a human cell line (ECV304)

This study assessed the effects of short-term adrenoceptor blockade on plasma matrix metalloproteinase (MMP) activity in patients with heart failure, and the ability of adrenoceptor stimulation to modulate matrix metalloproteinase-9 (MMP-9) promoter activity in vitro. Patients with heart failure received standard therapy or standard therapy plus carvedilol. Plasma MMP activity was determined by zymography and tissue inhibitor (TIMP-1) expression was measured by immunoblotting. MMP-9 promoter activity was assessed in transfected ECV304 cells following exposure to isoprenaline or phenylephrine in the absence or presence of either propranolol or prazosin. In patients with heart failure, carvedilol attenuated the increase in proMMP-9 activity observed at 4 and 12 weeks in non-beta-blocker-treated patients (44.0 +/- 4.9 AU versus 60.8 +/- 6.7 AU; P < 0.05). Although TIMP-1 expression was unaltered, the MMP-9:TIMP-1 ratio was lower in those receiving carvedilol at 4 and 12 weeks (0.54 +/- 0.07 versus 1.04 +/- 0.17; P < 0.05). Isoprenaline transiently increased MMP-9 promoter activity after 4 h exposure (80.6 +/- 14.8-fold; P < 0.001) before returning to baseline. The response to isoprenaline was prevented by propranolol (P < 0.01). Phenylephrine caused a biphasic increase in MMP-9 promoter activity, with the greatest increase occurring at 24 h (23 +/- 3.7-fold) compared to baseline. This response was unaffected by co-incubation with prazosin. In conclusion, treatment with a mixed alpha1/beta-adrenoceptor antagonist attenuates MMP activity and tips the degradative balance to a less degradative phenotype in heart failure patients. Furthermore, adrenoceptor stimulation increases MMP-9 promoter activity, which is inhibited by beta- but not alpha-adrenoceptor blockade. Therefore, mixed adrenoceptor blockade may reduce remodeling in heart failure as a direct consequence of a beta-adrenoceptor-mediated reduction in MMP-9 transcription.

Affinity purification and kinetic analysis of mutant forms of yeast NAD+-specific isocitrate dehydrogenase

Polyhistidine tags were added to the carboxyl termini of the two homologous subunits of yeast NAD+-specific isocitrate dehydrogenase (IDH). The tag in either the IDH1 or IDH2 subunit permits one-step affinity purification from yeast cellular extracts of catalytically active and allosterically responsive holoenzyme. This expression system was used to investigate subunit-specific contributions of residues with putative functions in adenine nucleotide binding. The primary effect of simultaneous replacement of the adjacent Asp-279 and Ile-280 residues in IDH1 with alanines is a dramatic loss of activation by AMP. In contrast, alanine replacement of the homologous Asp-286 and Ile-287 residues in IDH2 does not alter the allosteric response to AMP, but produces a 160-fold reduction in Vmax due to a 70-fold increase in the S0.5 value for NAD+. These results suggest that the targeted aspartate/isoleucine residues may contribute to regulator binding in IDH1 and to cofactor binding in IDH2, i.e. that these homologous residues are located in regions that have evolved for binding the adenine nucleotide components of different ligands. In other mutant enzymes, an alanine replacement of Asp-191 in IDH1 eliminates measurable catalytic activity, and a similar substitution of the homologous Asp-197 in IDH2 produces pleiotropic catalytic effects. A model is presented for the primary function of IDH2 in catalysis and of IDH1 in regulation, with crucial roles for these single aspartate residues in the communication and functional interdependence of the two subunits.

Expression and gene disruption analysis of the isocitrate dehydrogenase family in yeast

Mammalian and yeast cells contain three isozymes of isocitrate dehydrogenase: mitochondrial NAD- and NADP-specific enzymes and a cytosolic NADP-specific enzyme. Independent metabolic functions of these enzymes in Saccharomyces cerevisiae were examined by analyses of expression and of phenotypes displayed by mutants containing all possible combinations of isozyme gene disruptions. All three isocitrate dehydrogenases are expressed at high levels with growth on nonfermentable carbon sources, whereas the mitochondrial NADP-specific enzyme constitutes the major cellular activity with growth on glucose. Distinct growth phenotypes are observed for mutants expressing a single isozyme, and expression of at least one isozyme is necessary for glutamate-independent growth. The NADP-specific tricarboxylic acid cycle isocitrate dehydrogenase from Escherichia coli was expressed in mitochondrial and cytosolic compartments of the yeast disruption mutants using plasmids carrying gene fusions of yeast promoters and a mitochondrial targeting presequence with the bacterial coding sequence. The bacterial enzyme is competent for restoration of NADP-specific functions in either compartment but does not compensate for function of the yeast NAD-specific tricarboxylic acid cycle enzyme.

Assembly and function of a cytosolic form of NADH-specific isocitrate dehydrogenase in yeast

Mitochondrial NAD-dependent isocitrate dehydrogenase catalyzes a rate-limiting step in the tricarboxylic acid cycle. Yeast isocitrate dehydrogenase is an octomer composed of two subunits (IDH1 and IDH2) encoded by different genes and possessing independent mitochondrial targeting presequences. Oligonucleotide-directed mutagenesis was used to remove the presequences from each gene and from both genes carried on centromere-based expression plasmids. Effects on cellular localization were examined in a yeast strain containing chromosomal disruptions of IDH1 and IDH2 loci. Each subunit was found to be dependent upon its presequence for mitochondrial localization, and the subunits are independently imported into mitochondria under most growth conditions. Furthermore, an active holoenzyme can be assembled in the cytosol and this ''cytosolic'' form of isocitrate dehydrogenase can reverse the acetate- growth phenotype characteristic of the DeltaIDH1/ DeltaIDH2 disruption strain, indicating functional replacement of the mitochondrial enzyme. However, transformants containing plasmids lacking either the IDH1 or IDH2 presequence coding regions were unexpectedly found to be capable of growth on acetate medium. Further investigation demonstrated that cellular localization of the IDH1 subunit can be biased by this stringent growth pressure.