Biological and genetic characterization of a low-pathogenicity avian influenza H6N2 virus originating from a healthy Eurasian coot

Influenza A virus, A/Eurasian coot/Western Australia/2727/79 (H6N2), from an apparently healthy coot was characterized. This virus was able to grow on MDCK cells and produce a cytopathic effect in the absence of exogenous trypsin and was further characterized as a low-pathogenicity avian influenza virus, with an intravenous pathogenicity index of 0.15 and a ³²¹PQAETRG³²⁸ motif at the cleavage site of the haemagglutinin gene. It infected domestic chickens, resulting in seroconversion and intermittent virus excretion via cloaca and oropharynx under experimental conditions. Phylogenetic analysis showed that the viral genes were closely related to other waterfowl isolates from the same geographic area and time period.     

Salivary biomarkers for dental caries

As a highly prevalent multifactorial disease, dental caries afflicts a large proportion of the world's population. As teeth are constantly bathed in saliva, the constituents and properties of this oral fluid play an essential role in the occurrence and progression of dental caries. Various inorganic (water and electrolytes) and organic (proteins and peptides) components may protect teeth from dental caries. This occurs via several functions, such as clearance of food debris and sugar, aggregation and elimination of microorganisms, buffering actions to neutralize acid, maintaining supersaturation with respect to tooth mineral, participation in formation of the acquired pellicle and antimicrobial defense. Modest evidence is available on the associations between dental caries and several salivary parameters, including flow rate, buffering capacity and abundance of mutans streptococci. Despite some controversial findings, the main body of the literature supports an elevated caries prevalence and/or incidence among people with a pathologically low saliva flow rate, compromised buffering capacity and early colonization or high titer of mutans streptococci in saliva. The evidence remains weak and/or inconsistent on the association between dental caries and other saliva parameters, such as other possible cariogenic species (Lactobacillus spp., Streptococcus sanguis group, Streptococcus salivarius, Actinomyces spp. and Candida albicans), diversity of saliva microbiomes, inorganic and organic constituents (electrolytes, immunoglobulins, other proteins and peptides) and some functional properties (sugar clearance rate, etc.). The complex interactions between salivary components and functions suggest that saliva has to be considered in its entirety to account for its total effects on teeth.     

用石蜡作组织填充物的固定盒在阴茎癌放射治疗中的应用

目的:介绍一种自制用石蜡作组织填充物的固定盒在阴茎癌放射治疗中的应用。方法:用石蜡、塑料饭盒制作阴茎固定盒,用作阴茎癌的模拟定位和放射治疗。结果:阴茎位置固定良好,分次放疗摆位准确重复性好,患者舒适,剂量分布均匀。结论:阴茎癌的放射治疗由于其活动度大,不易固定,用石蜡作填充物的固定盒既解决了器官固定的难题,又修正了光子线的剂量建成区,使靶区剂量分布均匀,提高疗效,便于临床推广。     

High-dose dexamethasone regulates interleukin-18 and interleukin-18 binding protein in idiopathic thrombocytopenic purpura

To evaluate the effects of high-dose dexamethasone (HD-DXM) on the balance of interleukin-18 (IL-18) and its endogenous antagonist IL-18 binding protein (IL-18BP) in ITP patients, IL-18, IL-18BP as well as IFN-γ, IL-4 plasma levels and platelet counts were determined in 17 ITP patients receiving DXM 40 mg/day for four consecutive days and in 24 healthy subjects. Using RT-PCR, the mRNA expression of IL-18, IL-18BP, IFN-γ, IL-4, T-box (T-bet) and GATA-binding protein 3(GATA-3) were studied in all subjects. The in vitro effects of DXM on IL-18BP and IL-18 of peripheral blood mononuclear cells (PBMCs) were studied by ELISA. HD-DXM administration increased IL-18BP and reduced IL-18 expression significantly (p<0.05), which resulted in a downregulation of IL-18/IL-18BP ratio p<0.05). In vitro, DXM had a significant effect on secretion of IL-18BP while diminishing IL-18 release from cultures of PBMCs. These results suggest that downregulation of IL-18/IL-18BP might account for its clinical efficacy of HD-DXM in active ITP.     

Abnormalities of maternal thyroid function during pregnancy affect neuropsychological development of their children at 25–30 months

Objective To examine the relationship between specific thyroid abnormalities (subclinical hypothyroidism, hypothyroxinaemia or elevated thyroid peroxidase antibody titres) in women during pregnancy and the subsequent neuropsychological development of their offspring. Design/Patients Serum was collected from 1268 women at 16–20 weeks of gestation and thyroid stimulating hormone (TSH), total thyroxine (tT₄), free thyroxine (fT₄), and Thyroid peroxidase antibodies (TPOAb) levels were measured. Thyroid function reference ranges specific for pregnancy were used to screen for thyroid abnormalities. Patients with isolated subclinical hypothyroidism (18 cases), hypothyroxinaemia (19 cases), and those who were euthyroid patients with elevated titres of TPOAb (34 cases) were identified. One hundred and forty‐two euthyroid and TPOAb‐negative women matched for gestational age from the same cohort were selected as controls. Measurements Intellectual and motor development score evaluations were performed on the children from the pregnancies at 25–30 months of age. Results Children of women with subclinical hypothyroidism, hypothyroxinemia and elevated TPOAb titres had mean intelligence scores 8·88, 9·30 and 10·56 points lower than those of the control group (P = 0·008, P = 0·004 and P = 0·001, respectively); mean motor scores were 9·98, 7·57 and 9·03 points lower than those of the controls [P < 0·001, P = 0·007 and P < 0·001, respectively (t‐test)]. Unconditional multivariate logistic regression analysis showed that increased maternal serum TSH, decreased maternal serum tT₄, and elevated maternal TPOAb titres were separately associated with lower intelligence scores (ORs 15·63, 12·98, and 6·69, respectively) and poorer motor scores (ORs 9·23, 5·52, and 8·25, respectively). Conclusions Intellectual and motor development of children at 25–30 months of age is separately associated with abnormalities of maternal thyroid at 16–20 weeks gestation. Maternal subclinical hypothyroidism, hypothyroxinaemia or euthyroidism with elevated TPOAb titres were all statistically significant predictors of lower motor and intellectual development at 25–30 months.     

建立小型猪Ⅱ度根分叉缺损模型的可行性*★

背景：牙槽骨缺损再生的前提是建立可有效评价牙周骨组织再生的实验性牙槽骨缺损动物模型，以往研究用于观察牙周组织病变的模型动物多选用狗，但操作难度大。 目的：观察利用小型猪建立Ⅱ度根分叉缺损动物模型的可行性。 方法：制备小型猪Ⅱ度根分叉缺损模型。将小型猪实验牙随机分为2组，模型组造模后不注射任何药物干预，对照组于造模后注射具有成骨作用的辛伐他汀凝胶。 结果与结论：建模8周后大体、病理切片观察结果均显示模型组根分叉区空虚，对照组见新生牙槽骨长入。对照组可见较成熟的纤维组织以及增生的血管、大量成骨细胞、骨细胞，而模型组可见增生血管及少量成骨细胞。结果证实，以小型猪构建Ⅱ度根分叉缺损模型是可行的。