Immune responses of interferon gamma (IFN-gamma) knock out mice to repeated Haemaphysalis longicornis (Acari: Ixodidae) nymph infestations

To investigate the immunological mechanisms of acquired resistance to tick infestation, interferon gamma (IFN-gamma) deficient mice (IFN-gamma mice) were used to assess interleukin-4 (IL-4) and antibody production levels against tick salivary gland antigen on three successive infestations with Haemoaphysalis longicornis Neumann nymphs. The engorged body weight of the ticks decreased during the second and third infestations. Similar observations were noted in IFN-gamma+/+ mice. However, the engorged body weight of the ticks from IFN-gamma +/+ mice were considerably lower than those from IFN-gamma-/- mice. A marked increase in antibody production during the second and third infestations was observed indicating that IFN-gamma-/- mice could acquire immunological resistance against H. longicornis nymphs. Moreover, IL-4 levels were higher during the first and third infestations but decreased during the second infestation. IL-4 levels were significantly higher in IFN-gamma-/- mice than in IFN-gamma+/+ mice. We have shown here that the statistically significant high IL-4 levels observed in IFN-gamma-/- mice may be a result of type 2 helper cell (Th2) polarization. However, the apparently higher IL-4 levels during the first and third infestations and the notable decline during the second infestation suggest that other cytokines or factors in the host immune system may play a part in regulating IL-4 levels.     

Metformin and liraglutide ameliorate high glucose-induced oxidative stress via inhibition of PKC-NAD(P)H oxidase pathway in human aortic endothelial cells

Objective

Metformin and glucagon like peptide-1 (GLP-1) prevent diabetic cardiovascular complications and atherosclerosis. However, the direct effects on hyperglycemia-induced oxidative stress in endothelial cells are not fully understood. Thus, we aimed to evaluate the effects of metformin and a GLP-1 analog, liraglutide on high glucose-induced oxidative stress.

Methods

Production of reactive oxygen species (ROS), activation of protein kinase C (PKC) and NAD(P)H oxidase, and changes in signaling molecules in response to high glucose exposure were evaluated in human aortic endothelial cells with and without treatment of metformin and liraglutide, alone or in combination. PKC-NAD(P)H oxidase pathway was assessed by translocation of GFP-fused PKCβ2 isoform and GFP-fused p47phox, a regulatory subunit of NAD(P)H oxidase, in addition to endogenous PKC phosphorylation and NAD(P)H oxidase activity.

Results

High glucose-induced ROS overproduction was blunted by metformin or liraglutide treatment, with a further decrease by a combination of these drugs. Exposure to high glucose caused PKCβ2 translocation and a time-dependent phosphorylation of endogenous PKC but failed to induce its translocation and phosphorylation in the cells treated with metformin and liraglutide. Furthermore, both drugs inhibited p47phox translocation and NAD(P)H oxidase activation, and prevented the high glucose-induced changes in intracellulalr diacylglycerol (DAG) level and phosphorylation of AMP-activated protein kinase (AMPK). A combination of these drugs further enhanced all of these effects.

Conclusions

Metformin and liraglutide ameliorate high glucose-induced oxidative stress by inhibiting PKC-NAD(P)H oxidase pathway. A combination of these two drugs provides augmented protective effects, suggesting the clinical usefulness in prevention of diabetic vascular complications.     

Do self-assessed oral health and treatment need associate with clinical findings? Results from the Finnish Nationwide Health 2000 Survey

Objective. To associate self-assessed oral health and treatment need with clinically determined findings. Materials and methods. As part of the Finnish nationwide comprehensive Health 2000 Survey, the present cross-sectional study included dentate participants aged 30–64 years who self-assessed their oral health and treatment need in an interview and who underwent a clinical oral health examination (n = 4385). Self-assessed oral health and treatment need were used as subjective indicators. Clinically determined dental and periodontal status described objective dental and periodontal health and treatment need. The evaluation of relationships between subjective and objective findings was based on two-by-two tables and multivariate analyses. Results. The better the self-assessed oral health, the better the objective dental and periodontal health. Those reporting need for treatment more often had the objective need in terms of dental or periodontal treatment, also when controlling for background factors. Of the subjective indicators, good self-assessed oral health best reflected the absence of clinically determined dental or periodontal treatment need. Those who reported a need for treatment were mainly adults with an objective dental and periodontal treatment need. Conclusions. Self-assessed good oral health is a fairly good estimate for the absence of clinically determined dental and periodontal treatment need. As implication for practice, self-assessed data could be used for screening purposes for oral health service planning and for priority allocation in large adult populations.     

Estimating molar-incisor-hypomineralization among 8-year-olds based on 15-year public oral health practice-based data

Abstract

Background: A wide range in the prevalence of molar-incisor-hypomineralization (MIH) has been reported. Population-based studies are recommended. However, such studies are expensive and time-consuming.

Objectives: To estimate the magnitude of MIH condition among 8-year-olds based on routine oral health examinations and to associate first permanent molar (FPM) affection with that of other permanent teeth over time.

Materials and methods: This retrospective study, with cross-sectional and longitudinal components, was based on electronic oral health records; all 8-year-olds examined between 2002 and 2016 were included.

Results: The average estimated prevalence of MIH was 8.3%; yearly range was 4.8–15.9%. The mean number of affected teeth was 1.4; 62% had one affected tooth. One-surface defects were the most frequent (66%). Asymmetric distribution of affected teeth was observed. In follow-up, 10.7%, 8.4%, and 11.2% had at least one affected permanent canine, premolar, or second permanent molar, respectively. The proportion of children with other MIH-affected permanent teeth was higher in the group with ≥2 MIH-affected teeth than in group with one affected FPM at the age of 8.

Conclusions: The average prevalence of MIH was comparable to that reported elsewhere. The number of MIH-affected teeth at early mixed dentition predicts the affection of other permanent teeth over time, mainly that of permanent canines. Further screening of children with MIH is recommended to improve individually tailored early preventive and restorative dental care.     

Prevalence of Sarcocystis infection in horses in Mongolia

Sarcocystis infection was detected in 93% of horses in Mongolia. Using the compress method, sarcocysts were found in the muscles of the diaphragm, heart and tongue in 40 of the 43 horses that were slaughtered at the Makh Impex Meat Company in Ulaan Baatar in July 1998. The muscle of the tongue showed the highest rate (97.5%) of infection. The distribution of sarcocysts in the muscles was positively correlated with horse age; the rate of detection was significantly lower (p=0.01) in the under 10 year old group than the older group. All horses were apparently healthy and were slaughtered for human consumption.     

Attendance at and self-perceived need for continuing education among Mongolian dentists

In May 2000, a questionnaire-based survey was targeted at all Mongolian dentists practising in the capital city of Mongolia in May 2000 with the aim of evaluating attendance at and the self-perceived need for continuing education (CE) in relation to their background characteristics and to their attitude towards CE. The response rate was 98% (n = 245), with 38% of the dentists reporting a CE learning opportunity in at least one of the clinical disciplines of dentistry during the 2 years prior to the survey. A need for CE in at least one of the disciplines was perceived by 58%. A dentist's field of practice and attitude towards CE were the significant factors for attendance, whereas length of working experience, field of practice, holding a postgraduate degree, and having attended CE courses were significant factors for perceiving a need for CE, when controlling for all other variables in the logistic regression analyses (P < 0.05). There seems to be a need for an increased attendance at CE courses among the dentists and a need for preparing them to have a positive attitude towards CE. On the other hand, creating an organized CE system which produces courses for dental practitioners, based on their need, will be at present a challenge for the Mongolian dental profession.     

Preventive practice of Mongolian dental students

To investigate the preventive practice of Mongolian dental students, in relation to their knowledge of preventive care, self-perceived competency, oral self-care, and dental health status, a questionnaire was distributed to all (n = 79) clinical-year students of The Dental School of the Mongolian National Medical University. Dental students' reported preventive practice was explained by their knowledge of preventive care (P = 0.002) and self-perceived competency (P = 0.002), whereas their study-year, oral self-care, and dental health status, expressed as the Tissue Health Index (THI), remained statistically non-significant in the linear regression model. This explained 28% of the variation in the parameters examined. In logistic regression analysis, a student's study year (OR = 2.5), knowledge of preventive care (OR = 1.1), and THI (OR = 1.8) were related to their highest scores on preventive practice. Preventive practice among Mongolian dental students could be improved by increasing their knowledge, particularly in modern methods for caries-prevention such as fluoride, sealants, and xylitol. Preventive methods should be integrated into all topics of the dental curriculum and the learning environment should support such training for future oral health professionals.     

Molecular detection of tick‐borne pathogens in bovine blood and ticks from Khentii,Mongolia

Recent studies reported the detection of DNA from tick‐borne pathogens (TBPs) of veterinary relevance such as Anaplasma marginale, Babesia bigemina, Babesia bovis and Theileria orientalis in bovine blood samples from Mongolia. These findings were unexpected, as the known tick vectors of these pathogens are not known to occur in Mongolia. We therefore conducted a study in May and June 2013 in six districts of Khentii province where DNA of the said TBPs was previously found. Ticks collected from the vegetation and rodents, as well as blood samples from cattle, were screened for the presence of TBPs by reverse line blot (RLB) hybridization. Tick larvae collected from rodents were pooled. A total of 310 adult ticks were collected from the vegetation, and 249 tick larvae were collected from 24 rodents. Adult ticks (n = 2,318) and blood samples were collected from 481 heads of cattle. All adult ticks were identified as Dermacentor nuttalli. DNA from Rickettsia raoultii (252/310; 81.3%), an uncharacterized Anaplasma species preliminary named Anaplasma sp. Mongolia (26/310; 8.4%), Candidatus Midichloria sp. (18/310; 5.8%), Theileria equi (16/310; 5.2%), Babesia caballi (5/310; 1.6%), T. orientalis (1/310; 0.3%), Borrelia afzelii (1/310; 0.3%) and Candidatus Neoehrlichia mikurensis (1/310; 0.3%) was detected in ticks collected from the vegetation. DNA of R. raoultii (27/28; 96.4%) and Midichloria sp. (2/28; 7.1%) was detected in the pooled tick larvae. Anaplasma sp. Mongolia, a species related to Anaplasma ovis based on a multi‐locus analysis, was also detected in 153/481 (31.8%) of the bovine blood samples. DNA of B. bovis, B. bigemina and A. marginale was not detected in the ticks or bovine blood samples from Khentii district.     

Isolation, preliminary characterization, and full-genome analyses of tick-borne encephalitis virus from Mongolia

Tick-borne encephalitis virus (TBEV) causes one of the most important inflammatory diseases of the central nervous system, namely severe encephalitis in Europe and Asia. Since the 1980s tick-borne encephalitis is known in Mongolia with increasing numbers of human cases reported during the last years. So far, however, data on TBEV strains are still sparse. We herein report the isolation of a TBEV strain from Ixodes persulcatus ticks collected in Mongolia in 2010. Phylogenetic analysis of the E-gene classified this isolate as Siberian subtype of TBEV. The Mongolian TBEV strain showed differences in virus titers, plaque sizes, and growth properties in two human neuronal cell-lines. In addition, the 10,242 nucleotide long open-reading frame and the corresponding polyprotein sequence were revealed. The isolate grouped in the genetic subclade of the Siberian subtype. The strain Zausaev (AF527415) and Vasilchenko (AF069066) had 97 and 94?% identity on the nucleotide level. In summary, we herein describe first detailed data regarding TBEV from Mongolia. Further investigations of TBEV in Mongolia and adjacent areas are needed to understand the intricate dispersal of this virus.