[Research advances in transmission dynamic models on hand, foot, and mouth disease]

Hand, foot, and mouth disease (HFMD) is a common childhood infectious disease caused by various enteroviruses. China has the most significant number of reported cases and deaths of HFMD over the globe. Understanding the epidemic laws of HFMD can provide a scientific basis for designing prevention and control measures. The dynamic transmission models focus on the transmission mechanism of infectious diseases. They can simulate the actual situation to study the epidemic rules of diseases by adding, deleting, and subdividing compartments. More researchers have paid attention to dynamic models because of their high flexibility. To carry out the dynamic model of the HFMD research more effectively, a comprehensive understanding of related research progress in this field is deeply needed. In this paper, based on various researchers' different research purposes of dynamic models, the research progress was classified and summarized, providing meaningful guidance for model construction methods and future research directions and references for dynamic modeling of other models of infectious diseases. It was found that most studies used the SIR dynamic model or its extended model (such as the SEIR model), and few studies contained a complex factor compartment. Some important epidemiological parameters (such as R₀) were obtained by studying the HFMD cases in a specific region, simulating different intervention scenarios to evaluate the effect of measures, or revealing the future trend by model prediction. However, there is no dynamic model simultaneously considering age structure, population moving, seasonality and periodicity, and vaccination.

Oridonin Enhances the Anti-Metastasis Effect of Oxaliplatinliplatin on Colorectal Cancer Liver Metastasis

The anti-metastasis effect of oridonin in combination with oxaliplatin on colorectal cancer liver metastasis was studied using a BALB/c nude mouse model. The liver condition, bloody ascites, cholestasis, and liver metastasis scores in the three groups receiving oxaliplatin combined with oridonin were significantly milder than in the control group and importantly the anti-migratory effect of oxaliplatin combined with oridonin was obviously the strongest (p<0.05). Oridonin possessed no hepatotoxicity; instead, it effectively alleviated liver injury caused by oxaliplatin. Oridonin alone or in combination with oxaliplatin significantly decreased serum levels of α-fetoprotein and carcinoembryonic antigen. Therefore, oridonin combined with oxaliplatin displays great potential to markedly increase the anti-metastasis effect of oxaliplatin in the treatment of liver metastases of colorectal cancer.

Sequence variation in three mitochondrial genes among Gasterophilus intestinalis isolates from two distinct regions in China

Horse gastrointestinal myiasis caused by larvae of Gasterophilus spp. has a worldwide distribution. However, little information is available on the genetic variation of Gasterophilus spp. at the molecular level. In the present study, sequence variation was examined in three mitochondrial (mt) genes, namely mt cytochrome c oxidase subunit 1 (cox1), NADH dehydrogenase subunits 5 (nad5) and large subunit ribosomal RNA (rrnL), among G. intestinalis isolates originating from Heilongjiang Provience and Xinjiang Uygur Autonomous Region, China. The complete cox1, nad5, and rrnL gene sequences were amplified by PCR separately from adult G. intestinalis individuals and the amplicons were sequenced from both directions. The size of the sequences of cox1, nad5, and rrnL genes was 1539 bp, 1717 bp, and 1321 bp, respectively. The A + T contents of the sequences were 62.7-63.9% (cox1), 70-70.7% (nad5), and 74.5-74.9% (rrnL). The intra-specific sequence variations within G. intestinalis were 0.1-3.1% for cox1, 0.4-3.4% for nad5, and 0.1-1.5% for rrnL. Phylogenetic analyses based on the cox1 sequences using the Bayesian inference indicated that all the G. intestinalis isolates grouped together with high statistical support. These findings demonstrated clearly the usefulness of mt cox1, nad5, and rrnL sequences for the molecular identification and for studying population genetics of G. intestinalis in horses.

Genetic variability among Hymenolepis nana isolates from different geographical regions in China revealed by sequence analysis of three mitochondrial genes

Hymenolepis nana is a common tapeworm that parasitizes in the small intestine of rodent animals and humans. The present study examined the sequence diversity of three mitochondrial (mt) genes namely NADH dehydrogenase subunits 5 (nad5), small subunit ribosomal RNA (rrnS), and ATPase subunit 6 (atp6) of H. nana from mice in different geographical regions of China. A part of the nad5 (pnad5), complete rrnS and atp6 genes were amplified separately from individual H. nana isolates using polymerase chain reaction (PCR) and then sequenced. The sequences of pnad5, rrnS, and atp6 were 710 bp, 704-711 bp, and 516 bp in length, respectively. The A + T contents of the sequences were 70.1-73.5% (pnad5), 70.1-71.7% (rrnS), and 76.6-77.9% (atp6). Sequence variation within H. nana was 0-1.4% for atp6, 0-1.7% for rrnS, and 0-0.7% for pnad5. The inter-specific sequence differences between H. nana and Hymenolepis diminuta were significantly higher, which was 31.6-31.7% (pnad5), 16.1-17.6% (rrnS), and 26.5-27.1% (atp6). Phylogenetic analysis based on the combined three sequences using the maximum parsimony (MP) method supported that H. nana is a species complex or "cryptic" species. These findings demonstrated clearly the usefulness of the three mtDNA sequences for population genetics and systematic studies of H. nana of human and animal health significance.

Complete Mitochondrial genome of an equine intestinal parasite, Triodontophorus brevicauda (Chromadorea: Strongylidae): the first characterization within the genus

The complete mitochondrial (mt) genome sequence of Triodontophorus brevicauda, an intestinal equine nematode parasite was determined for the first time. The circular T. brevicauda mt genome is 14,305 bp in length and contains 36 genes, of which 12 code for protein, 22 for transfer RNA, and two for ribosomal RNA, and lacks atp8 mtDNA gene. Phylogenetic analysis based on the concatenated amino acid sequence of the 12 protein-coding genes was performed using three different tree-building methods. The Strongyloidea cluster divides into two large branches, and each nematode family included in our study forms an independent clade, though paraphyly confounds the issue at some nodes. T. brevicauda clusters together with Cylicocyclus insignis with high statistical support. The mtDNA data in this study not only provide a new mtDNA resource for phylogeny, but also become a novel and useful genetic marker for further studies on the identification, population genetics, and molecular epidemiology of the genus Triodontophorus in equine.

Prevalence of Clonorchis sinensis infection in freshwater fishes in northeastern China

The prevalence of Clonorchis sinensis infection in freshwater fishes was surveyed in Heilongjiang Province, northeastern China, between August 2011 and September 2013. Thirteen species of freshwater fish (n=3221) and one species of shrimp (n=93) were collected from Songhua river, Nenjiang river and other lakes or ponds in 37 sites of 15 representative cities in Heilongjiang Province. They were individually examined by digestion technique, and the C. sinensis metacercariae were identified morphologically followed by confirmation using sequences of the second internal transcribed spacer of ribosomal DNA. Ten of the 13 examined species of freshwater fishes were infected with C. sinensis metacercariae, while all shrimps were negative. The overall prevalence of C. sinensis infection in 3221 examined freshwater fishes was 19.96%, with 42.57% (272/639) in Pseudorasbora parva, 22.55% (83/368) in Hemicculter leuciclus, 20.44% (121/592) in Carassius auratus, 17.71% (68/384) in Saurogobio dabryi, 10.85% (23/212) in Rhodeus ocellatus, 10.54% (48/455) in Phoxinus lagowskii, 8.20% (21/256) in Perccottus glehnii, 6.25% (5/80) in Misgurnus anguillicaudatus, 4.55% (1/22) in Xenocypris davidi, and 1.49% (1/67) in Cyprinus carpio. The average infection intensity in P. parva was 103.3 encysted metacercariae per gram of fish meat in Zhaoyuan city. The average prevalence of C. sinensis infection in Songhua river, Nenjiang river and lakes or ponds were 31.96% (503/1574), 11.30% (102/903) and 7.93% (59/744), respectively. The prevalence of C. sinensis infection in Zhaoyuan city (43.68%) was the highest among all sampling locations. These results revealed a high-prevalence of C. sinensis infection in freshwater fishes in Heilongjiang Province, northeastern China, posing significant public health concern.

Abstract P1-08-05: The Establishment of Rat Model of Premalignant Breast Disease and Histomorphological Study of Rats’ Premalignant Disease

Background:The treatment of breast cancer requires not only a reasonable strategy, but also effective preventive measures. Study of precancerous lesions can help explore the pathogenesis of breast cancer, and its mechanism is important of vesting. In view of long-term progressive pathological process and many co-exsited factors, it is difficult to observe the process in the human being itself, the establishment of a suitable animal model can surve to provide experimental basis for the prevention of premalignancy of breast cancer's transfer mechanism and have a great value.At present, the establishment of breast hyperplasia animal model is mature and unsuccessful for difficulty to determine the end of experiment.

Methods: 54 SD rats were randomly divided into 7 groups. Observation of GroupII-VII last for 32 weeks.

GroupI:blank control ,NS 1ml ig in the first day,0.5 ml NS intraperitoneal injection at the 2nd -25th days ,then stop for 5 days .30 days is one cycle ,observe 7 cycles.

GroupII: DMBA only.DMBA ig in the first day with the dose of 10mg/kg DMBA GroupIII: DMBA +hormone sequential 5 days.DMBA ig in the first day with the dose of 10mg/kg DMBA ,estradiol benzoate intraperitoneal injection with the dose of 0.5mg/kg.day at the 1st -3rd days. Progestin intraperitoneal injection with the dose of 4mg/kg.day at the 4th day. one cycle was 5 days

GroupIV: DMBA +hormone sequential 30 days.DMBA ig in the first day with the dose of 10mg/kg DMBA ,estradiol benzoate intraperitoneal injection with the dose of 0.5mg/kg.day at the 1st -21st days. Progestin intraperitoneal injection with the dose of 4mg/kg.day at the 22nd-25th days. one cycle was 30 days

Group V:MNU only; DMBA only; MNU ig in the first day with the dose of 5mg/kg .

Group VI: MNU +hormone sequential 5 days.MNU ig in the first day with the dose of 5mg/kg, estradiol benzoate intraperitoneal injection with the dose of 0.5mg/kg.day at the 1st -3rd days. Progestin intraperitoneal injection with VII: MNU +hormone sequential 30 days .,MNU ig in the first day with the dose of 5mg/kg, ,estradiol benzoate intraperitoneal injection with the dose of 0.5mg/kg.day at the 1st -21st days. Progestin intraperitoneal injection with the dose of 4mg/kg.day at the 22nd-25th days. one cycle was 30 days.

After the 14th week, one pair of breast of every group was taken out to perform the histomorphological changes until all the rats were executed in the 32nd week.

Result:The total incidence of premalignant breast disease of DMBA group was 47%, while MNU group 8%,with statistical significance. No statistical significan was observed within the subgroup of DMBA. Most of premalignant lesions occurred during the 20th to 28th weeks. See Table 1.

Pathological results of 7 Groups

Discussion

MNU is not fit for inducing the premalignant lesions of SD rats. DMBA is a better medicine to observe the premalignant lesions of SD rats.

The 20-28 weeks is the best interval to observe the premalignant lesions.

[Study of emotional disorders and their risk factors in patients hospitalized with lower extremity fracture]

111 adult patients hospitalized with lower extremity fracture (LEF) at three teaching hospitals of Beijing Medical University were interviewed by using STAI and CES-D. The results showed that the prevalence of depression in this group using CES-D is 69.4%, and there was a high correlation between STAI scores and CES-D scores. Multivariante analyses indicated that physical status, financial crisis, age, knowledge about disease, especially the patients' perceived threat of fracture, and social supports were the main factors that contribute to the patients' emotional distress.