Cytotoxic innate intraepithelial lymphocytes control early stages of Cryptosporidium infection.

Background: Intraepithelial lymphocytes (IELs) are the first immune cells to contact and fight intestinal pathogens such as Cryptosporidium, a widespread parasite which infects the gut epithelium. IFN-γ producing CD4+ T IELs provide an efficient and a long-term protection against cryptosporidiosis while intraepithelial type 1 innate lymphoid cells limits pathogen spreading during early stages of infection in immunodeficient individuals. Yet, the role of T-cell like innate IELs, the most frequent subset of innate lymphocytes in the gut, remains unknown. Methods: To better define functions of innate IELs in cryptosporidiosis, we developed a co-culture model with innate IELs isolated from Rag2-/- mice and 3D intestinal organoids infected with C. parvum using microinjection. Results: Thanks to this original model, we demonstrated that innate IELs control parasite proliferation. We further showed that although innate IELs secrete IFN-γ in response to C. parvum, the cytokine was not sufficient to inhibit parasite proliferation at early stages of the infection. The rapid protective effect of innate IELs was in fact mediated by a cytotoxic, granzyme-dependent mechanism. Moreover, transcriptomic analysis of the Cryptosporidium-infected organoids revealed that epithelial cells down regulated Serpinb9b, a granzyme inhibitor, which may increase their sensitivity to cytolytic attack by innate IELs. Conclusion: Based on these data we conclude that innate IELs, most likely T-cell-like innate IELs, provide a rapid protection against C. parvum infection through a perforin/granzymes-dependent mechanism. C. parvum infection. The infection may also increase the sensitivity of intestinal epithelial cells to the innate IEL-mediated cytotoxic attack by decreasing the expression of Serpin genes.

Multispacer sequence typing of Coxiella burnetii from milk and hard tick samples from ruminant farms in Lebanon.

his study was carried out to detect and characterize Coxiella burnetii in ruminant milk samples and in different tick species from seropositive farms in four Lebanese regions. Milk and tick samples were screened for C. burnetii presence by quantitative real-time PCR (qPCR) targeting IS1111 region followed by multispacer sequence typing (MST). The overall positive percentages of 9.6% (27/282) and 95.45% (84/88) for C. burnetii were recorded in ruminant milk and tick samples, respectively. In detail, the C. burnetii DNA was recorded in 52/54 (96.3%) of Rhipicephalus annulatus, 20/21 (95.24%) of Rhipicephalus turanicus, 6/6 (100%) of Hyalomma anatolicum, 5/6 (83.3%) of Rhipicephalus sanguineus and 1/1 of Rhipicephalus bursa. After genotyping of some IS1111-positive samples (17/111), different MST genotypes were identified. Out of 15 positive ticks, 10 were infected with MST2 genotype, 4 were infected with MST7 genotype and 1 was infected with MST57. Moreover, genotypes MST20 and MST58 were found in one cow and one goat milk samples, respectively. The present study confirmed the high genetic diversity of C. burnetii in Lebanon.

Measurement Reliability of the Remaining Dentin Thickness below Deep Carious Lesions in Primary Molars.

AIM: This study was carried out to assess the reliability of measurements of the remaining dentin thickness under deep carious lesions as estimated from digital radiographs. The goal is to allow clinicians to correlate the radiographic measurement to the exact value of the remaining dentin thickness. The results obtained will be tested further in a study that will evaluate the histopathologic pulpal state according to the caries' lesion depth. MATERIALS AND METHODS: The study was conducted in the Pediatric Dentistry Department at the Lebanese University, in collaboration with the research platform of the same university. Fifty deciduous molars with deep caries on proximal surfaces liable to extraction were collected. Before extraction, a digital in vivo periapical radiograph was taken, followed by manual excavation of the caries. After excavation, another radiograph was taken before the tooth was sectioned through the deepest site of the lesion. Another radiograph was then obtained for each tooth fragment. To evaluate the exact thickness of the remaining dentin, each fragment was measured on a histologic macropho-tograph. The measurements were then compared statistically using a paired-samples t-test, and a correlation was sought. RESULTS: No significant difference was observed in the radiographs between the measurement of the remaining dentin thickness before and after the excavation of caries. In contrast, the radiographic measurements of remaining dentin thickness were underestimated by an average of 20% compared with those made with macrophotographs. LIMITATIONS: Interpretation of radiographs varies from one practitioner to another and is a function of the operator's visual acuity. CONCLUSION: Measuring the residual dentin thickness on a radiograph underestimates the actual thickness by about 20%. Further studies are needed to confirm these results. CLINICAL SIGNIFICANCE: Our results indicate that remaining dentin thickness is greater in reality than is shown on a radiograph. This information can help clinicians to refine their diagnoses and treatment plans.How to cite this article: Berbari R, Khairallah A, Kazan HF, Ezzedine M, Bandon D, Sfeir E. Measurement Reliability of the Remaining Dentin Thickness below Deep Carious Lesions in Primary Molars. Int J Clin Pediatr Dent 2018;11(1):23-28.

The First Serological Study of Q Fever in Humans in Lebanon.

OBJECTIVE: The aim of this study was to estimate, for the first time, the human seroprevalence of Q fever in Lebanon, by assessing the presence of antibodies against the causative agent, Coxiella burnetii. A total number of 421 serum samples (226 females and 196 males) were collected in February 2015 from hospitals and laboratories dispersed in five Lebanese provinces: Akkar, Bekaa, Mount Lebanon, Nabatieh, and South Lebanon. METHODS: Serial testing approach was used. Samples were first screened for IgG phase II antibodies against C. burnetii by Enzyme Linked Immunosorbent Assay (ELISA) Kit. Then, both positive and inconclusive sera were reexamined by immunofluorescence assay (IFA) test with the aims to confirm and specify the infection status (past or probably acute infection) by detecting IgG (I/II) and IgM (I/II) in human sera. RESULTS: Screening of 421 samples was estimated to be 38.70% (95% CI 34-43.3) positive samples, 5.90% (95% CI 3.7-8.2) suspect samples (as doubtful results), and 55.40% (95% CI 50.7-60.1) negative samples. Furthermore, all positive and suspect samples by ELISA test were retested by immunofluorescence assay test (IFAT), and the prevalence of positive sample was 37% and the infection case was recorded: 23.75% (95% CI 19.7-27.8) samples resulted from past infection, 1.9% (95% CI 0.6-3.2) probably acute infection characterized by several dominance clinical symptoms as: fever, cough, headache, difficulty breathing, and atypical pneumonia, and 0.23% (95% CI 0-0.7) inconclusive sample accompanied by different symptoms as bone metastasis and lung cancer. CONCLUSION: The study records the exposition of 37% of 421 patients to C. burnetii distributed in five Lebanese provinces with the highest seroprevalence in Bekaa and Akkar provinces and the lowest reported in Mount Lebanon. This difference may be due to the presence of high density of livestock production and of major agricultural areas in these two provinces.

Relationship Between the Remaining Dentin Thickness and Coronal Pulp Status of Decayed Primary Molars.

AIMS AND OBJECTIVES: The aim of this study was to assess the correlation between the remaining dentin thickness (RDT) in deep decayed primary molars and the inflammatory status and bacterial composition of the corresponding coronal pulp. We hypothesized that RDT could be used as a reference for clinicians in assigning the indication for pulpotomy. MATERIALS AND METHODS: Pulpotomies were conducted on the cameral pulp of 48 primary molars. Microorganisms, such as Lactobacillus sp., Streptococcus sp., and Prevotella sp., were identified and quantified and levels of tumor necrosis factor-alpha (TNF-α) and interlukin-6 (IL-6) were assessed. The correlation between the pre-operative RDT based on radiographic images and inflammatory-microbial profiles in vitro was evaluated using Spearman's rho correlation coefficient. All data analysis was performed using a statistical software program (SPSS 20.0, SPSS Inc., Chicago, IL, USA). RESULTS: Immunological and microbiological studies revealed elevated levels of TNF-α and IL-6 cytokines, and Lactobacillus sp., Streptococcus sp. and Prevotella sp. in the cameral pulp with an RDT measuring up to 1.1 mm. No significant relationship could be established between RDT, inflammatory status and microbial content of the pulps. CONCLUSION: The RDT remains a key clinical factor that needs to be assessed when establishing the indication for pulpotomy. Additional parameters that can improve this therapy should be investigated in the future.

Diversity and distribution of ticks from domestic ruminants in Lebanon.

Ticks (Acari: Ixodidae) are ectoparasites infesting livestock in every geographic area in the world and they are vectors of several viral, bacterial, and protozoan pathogens to animals and humans worldwide. A deep knowledge of the geographical distribution of these arthropods would have a key role in the control of tick-borne diseases. Few data are available about tick presence in domestic ruminants in Lebanon. The study aimed at providing an analysis of tick presence and distribution in Lebanon. Ticks were collected from cattle, sheep, and goats farms distributed in 6 Lebanese provinces between June and September 2014. A total of 272 adult hard ticks were randomly collected from domestic ruminants (cattle, sheep, and goats) located at 37 Lebanese farms, distributed among 30 villages. Ticks belonged to 4 Ixodidae genera: Rhipicephalus (72.4%), Haemaphysalis (11.4%), Dermacentor (8.1%), and Hyalomma (8.1%). They included the following species: Rhipicephalus annulatus (50.7%), Rhipicephalus turanicus (18.8%), Hyalomma anatolicum (8.1%), Haemaphylasis punctata (11.4%), Dermacentor marginatus (8.1%), Rhipicephalus sanguineus (2.5%), and Rhipicephalus bursa (0.4%). Rhipicephalus turanicus and H. anatolicum were found on cattle, sheep, and goats, R. annulatus on cattle and sheep, R. sanguineus, D. marginatus and Hea. punctata on sheep and goats, while R. bursa was collected only on sheep. Tick species involved in pathogen transmission were found and some of the identi ed species were recorded in Lebanon for the rst time.

The combination of arsenic, interferon-alpha, and zidovudine restores an "immunocompetent-like" cytokine expression profile in patients with adult T-cell leukemia lymphoma.

BACKGROUND: HTLV-I associated adult T-cell leukemia/lymphoma (ATL) carries a dismal prognosis due to chemo-resistance and immuno-compromised micro-environment. The combination of zidovudine and interferon-alpha (IFN) significantly improved survival in ATL. Promising results were reported by adding arsenic trioxide to zidovudine and IFN. RESULTS: Here we assessed Th1/Th2/T(reg) cytokine gene expression profiles in 16 ATL patients before and 30 days after treatment with arsenic/IFN/zidovudine, in comparison with HTLV-I healthy carriers and sero-negative blood donors. ATL patients at diagnosis displayed a T(reg)/Th2 cytokine profile with significantly elevated transcript levels of Foxp3, interleukin-10 (IL-10), and IL-4 and had a reduced Th1 profile evidenced by decreased transcript levels of interferon-γ (IFN-γ) and IL-2. Most patients (15/16) responded, with CD4⁺CD25⁺ cells significantly decreasing after therapy, paralleled by decreases in Foxp3 transcript. Importantly, arsenic/IFN/zidovudine therapy sharply diminished IL-10 transcript and serum levels concomittant with decrease in IL-4 and increases in IFN-γ and IL-2 mRNA, whether or not values were adjusted to the percentage of CD4⁺CD25⁺ cells. Finally, IL-10 transcript level negatively correlated with clinical response at Day 30. CONCLUSIONS: The observed shift from a T(reg)/Th2 phenotype before treatment toward a Th1 phenotype after treatment with arsenic/IFN/zidovudine may play an important role in restoring an immuno-competent micro-environment, which enhances the eradication of ATL cells and the prevention of opportunistic infections.