Seasonal distribution of Rickettsia spp. in ticks in northeast Algeria.

This article discusses research conducted on the sampling of two tick species: Ixodes ricinus and Rhipicephalus bursa. Ticks were collected in northern Algeria (El Tarf) in 2014 and studied for differences in abundance and seasonal distribution of population dynamics, as well as tested by PCR for the presence of Rickettsia spp. By molecular tools, four Rickettsia pathogens agents were detected: R. helvetica, R. monacensis, R. raoultii and R. massiliae.

Diffractive refractometer for liquid characterization and transient processes monitoring.

A simple refractometer using a reflective diffraction grating immersed in the test liquid is developed and its performance is studied. Due to the dependence of the light wavelength on the refractive index, determining the angle of the diffracted beam provides the refractive index of the liquid. The glass cell containing the test liquid is cylindrical, and the grating plane is parallel to the cylinder symmetry axis. The light beam normally impinges on the cell front wall and reaches the center of the grating so that the diffracted beam leaves the cell without being deviated by refraction. It is demonstrated that this characteristic of the optical setup minimizes important error sources due to undesired beam deviations and enables real-time refractive index measurement of liquids in transient processes. Moreover, the performances of the diffractive refractometer and of a commercial Abbe refractometer are compared in the measurement of the refractive indexes of aqueous NaCl solutions. A He-Ne laser at 632.8 nm is used as a light source, and the diffraction grating has 1200 lines/mm. Measurement precisions of the order of 8 × 10-4 are achieved.

Immersed diffraction grating refractometers of liquids.

In this work, we report the development, construction, and the performance of two liquid refractometers that use a reflective diffraction grating immersed in a test liquid. The liquid is contained in a transparent glass cell with a rectangular cross section. The grating is oriented in such a way that the propagation directions of the incident beam and the beam diffracted by the lower part of the grating immersed in the liquid are perpendicular. In this configuration, the refractive index is determined by measuring the angle of the zeroth-order diffraction beam coming from the upper part of the grating, which is in contact with air. The diffractive refractometers (DR-1 and DR-2) have different angle measurement procedures and different light detection systems, and their advantages and drawbacks are pointed out. In the experiments, precisions of the order of 10-5 and 10-4 for DR-1 and DR-2 are achieved, respectively. The performances of both systems are compared with the performance of a commercial Abbe refractometer in the measurement of sugar and NaCl aqueous solutions.

Extraoral implants for orbit rehabilitation: a comparison between one-stage and two-stage surgeries.

The aim of the study was to compare the osseointegration success rate and time for delivery of the prosthesis among cases treated by two-stage or one-stage surgery for orbit rehabilitation between 2003 and 2011. Forty-five patients were included, 31 males and 14 females; 22 patients had two-stage surgery and 23 patients had one-stage surgery. A total 138 implants were installed, 42 (30.4%) on previously irradiated bone. The implant survival rate was 96.4%, with a success rate of 99.0% among non-irradiated patients and 90.5% among irradiated patients. Two-stage patients received 74 implants with a survival rate of 94.6% (four implants lost); one-stage surgery patients received 64 implants with a survival rate of 98.4% (one implant lost). The median time interval between implant fixation and delivery of the prosthesis for the two-stage group was 9.6 months and for the one-stage group was 4.0 months (P < 0.001). The one-stage technique proved to be reliable and was associated with few risks and complications; the rate of successful osseointegration was similar to those reported in the literature. The one-stage technique should be considered a viable procedure that shortens the time to final rehabilitation and facilitates appropriate patient follow-up treatment.

Natural History of Innate Host Defense Peptides.

Host defense peptides act on the forefront of innate immunity, thus playing a central role in the survival of animals and plants. Despite vast morphological changes in species through evolutionary history, all animals examined to date share common features in their innate immune defense strategies, hereunder expression of host defense peptides (HDPs). Most studies on HDPs have focused on humans, domestic and laboratory animals. More than a thousand different sequences have been identified, yet data on HDPs in wild-living animals are sparse. The biological functions of HDPs include broad-spectrum antimicrobial activity and immunomodulation. Natural selection and coevolutionary host-pathogen arms race theory suggest that the extent and specificity of the microbial load influences the spectrum and potency of HDPs in different species. Individuals of extant species-that have lived for an extended period in evolutionary history amid populations with intact processes of natural selection-likely possess the most powerful and well-adapted "natural antibiotics". Research on the evolutionary history of the innate defense system and the host in context of the consequences of challenges as well as the efficacy of the innate immune system under natural conditions is therefore of immediate interest. This review focuses on evolutionary aspects of immunophysiology, with emphasis on innate effector molecules. Studies on host defense in wild-living animals may significantly enhance our understanding of inborn immune mechanisms, and help identify molecules that may assist us to cope better with the increasing microbial challenges that likely follow from the continuous amplification of biodiversity levels on Earth.

Innate immunity and host defense peptides in veterinary medicine.

Recent years have witnessed a surge in interest directed at innate immune mechanisms. Proper conceptualization of the key elements of innate immunity, however, is still a work in progress, because most research in immunology traditionally has been focused on components of the acquired immune response. The question of why an animal stays healthy in a world filled with many dangers is perhaps as interesting as why it sometimes surrenders to disease. Consequently, studies with an increased focus on inborn mechanisms of animal host defense may help further the development of appropriate preventative and therapeutic measures in veterinary medicine. Host defense peptides (HDPs) are central effector molecules of innate immunity, and are produced by virtually all living species throughout the plant and animal kingdoms. These gene-encoded peptides play a central role in multiple, clinically relevant disease processes. Imbalances in the expression of HDPs can lead to overt pathology in different organ systems and cell types in all species studied. In addition, HDPs are an ancient group of innate chemical protectors, which are now evaluated as model molecules for the development of novel natural antibiotics and immunoregulatory compounds. This review provides an overview of HDPs and is aimed at veterinary practitioners as well as basic researchers with an interest in comparative immunology involving small and large animal species.

Two randomized vitamin D trials in ambulatory patients on anticonvulsants: impact on bone.

OBJECTIVE: To investigate the effects of two doses of vitamin D given over 1 year on bone density in ambulatory patients on long-term antiepileptic drug (AED) therapy. METHODS: We conducted two parallel, randomized, controlled trials in 72 adults (18 to 54 years old) and 78 children and adolescents (10 to 18 years) on long-term AED therapy. They received either low-dose vitamin D 400 IU/day or high-dose vitamin D 4,000 IU/day (adults) and 2,000 IU/day (children/adolescents). Bone mineral density (BMD) was measured using dual-energy x-ray absorptiometry. RESULTS: In adults, baseline BMD was lower than that of age- and gender-matched controls vs either a Western or an ethnically identical population. After 1 year, there were significant increases in BMD at all skeletal sites compared to baseline in the high-, but not in the low-dose treatment group. However, BMD at 1 year remained below normal. In children, baseline BMD was normal vs age- and gender-matched controls and showed significant and comparable increases in both treatment groups. CONCLUSIONS: In ambulatory adults on antiepileptic drugs, high-dose vitamin D therapy substantially increased bone mineral density at several skeletal sites. In children, both doses resulted in comparable increases in bone mass.

Opportunistic actinomycosis in osteoradionecrosis of the jaws in patients affected by head and neck cancer: incidence and clinical significance.

Actinomycosis is occasionally an opportunistic infection occurrence in patients with osteoradionecrosis (ORN). A retrospective study (1992-97) of 50 patients with ORN of the jaws was done to evaluate the incidence and its clinical significance in the management of ORN. Actinomycosis was diagnosed in 12% of ORN cases. In 36 of the 50 patients including five cases of actinomycosis, the ORN was considered to be resolved after treatment. The median treatment duration of ORN was significantly longer (P<0.007) in patients with actinomycosis (29.7 months) than those without the disease (13.4 months). In conclusion, bone biopsy should be considered in cases of ORN with unsatisfactory response to its specific therapies, aiming to identify possible opportunistic actinomycosis infection.

Management of refractory osteoradionecrosis of the jaws with surgery and adjunctive hyperbaric oxygen therapy.

This retrospective study aimed to determine the effectiveness of surgery and hyperbaric oxygen (HBO) treatment in the management of refractory osteoradionecrosis (ORN) of the jaws. Of the 18 patients who had undergone this treatment, 14 patients had complete healing, 3 patients had improved and one patient did not show any improvement. Of the 14 patients who had complete healing, only 4 still had a discontinuity defect of the mandible but they declined additional reconstructive surgery. In conclusion, surgery/HBO therapy showed satisfactory results in the management of refractory ORN of the jaws.

Myofibroma of gingiva: report of a case with immunohistochemical and ultrastructural study.

Oral myofibroma is an uncommon, benign, solitary proliferation of myofibroblastic tissue. Few cases affecting maxillofacial region have been reported. We present a case of gingival myofibroma, diagnosed on clinical, histopathological, immunohistochemical, and ultrastructural basis.

Management of solid ameloblastoma of the jaws with liquid nitrogen spray cryosurgery.

OBJECTIVE: This study evaluated the results of the use of curettage followed by liquid nitrogen spray cryosurgery in a number of solid or multicystic ameloblastomas of the jaws and the postoperative complications related to this treatment modality. STUDY DESIGN: Thirty-six patients with solid ameloblastoma of the jaws were treated with curettage followed by cryosurgery. The cryotherapy consisted of hand instrumented curettage of the bone lesion followed by three freezing cycles, of 1 minute each, of the remaining bone cavity with liquid nitrogen spray. Postoperative complications were evaluated clinically and radiographically. RESULTS: Local recurrence occurred in 11 (30.6%) patients. Excepting local recurrence, postoperative complications were frequent but not severe: wound dehiscence (5.5%), paraesthesia (5.5%), infection (5.5%), and pathologic fracture (11.1%). CONCLUSION: Management of solid or multicystic ameloblastomas of the jaws with curettage followed by cryosurgery may decrease the local recurrence rate and also to reduce the initial indication of resection with continuity defect.

Osteoradionecrosis of the jaws: a retrospective study of the background factors and treatment in 104 cases.

PURPOSE: This study analyzed potential risk factors in patients who received radiation therapy and then developed osteoradionecrosis (ORN). PATIENTS AND METHODS: A group of 104 patients who developed osteoradionecrosis of the jaws were reviewed treated between 1972 and 1992. RESULTS: The most common affected site was the mandible (99 cases, 95.2%), followed by the maxilla (5 cases, 4.8%). Among all cases, 93 (89.4%) were induced-trauma ORN, and 11 (10.6%) were spontaneous ORN. The following risk factors were considered as predisposing factors for the appearance of ORN: Anatomic location of the tumor, tumor surgery, total radiation dose, dose rate/day, mode of radiation delivery, time from radiation therapy until the onset of ORN, and dental status. ORN developed more frequently with oral cancer than other head and neck cancers. The size of the tumor seemed not to influence the incidence of ORN except when the tumor invade the adjacent bone. Type of radiation delivery total bone dose, and modes of radiation appeared to influence the risk of ORN occurrence. After conservative treatment, 44 (42.3%) cases had complete healing and resolution 34 (32.6%) cases had a stable, chronic ORN process, and 26 (25.1%) cases had acute and progressive ORN. CONCLUSION: An understanding of the risk factors is important in preventing ORN after radiation therapy.

Race and gender influences on the survival of patients with mouth cancer.

Previous studies have shown that race and gender are important correlates of survival among patients with cancer of certain sites. Since race and gender influence the stage of disease at diagnosis and the choice of therapy it has been argued that survival differentials may not be real but instead, they represent secondary associations with clinical variables. Therefore, verification of the true prognostic effects of race and gender requires proper controlling for potential confounders, such as stage and treatment. We have studied the 15-year survival experience of a hospital-based cohort of 4527 patients diagnosed with cancer of the mouth over a 28-year period in Brazil. Race and gender were strong predictors of stage and treatment. The odds ratios for no treatment were 1.35 (95% confidence limits [CL]: 1.09, 1.66) for females and 1.63 (CL: 1.29, 2.06) for non-white patients even after adjustment by stage, presumably a key criterion to define treatment. Survival differentials were found for lip cancer, with respect to race, and for cancers of the gum, floor of mouth, and other oral subsites, with respect to gender. Non-whites experienced 2.1 times the risk of lip cancer recurrence (CL: 1.20, 3.61) and 2.3 times the risk of dying from it (CL: 1.29, 4.09) as compared to whites. However, controlling for stage and treatment modality variables by proportional hazards regression reduced the same risk ratios to 1.01 (CL: 0.57, 1.78) and 1.17 (CL: 0.65, 2.13), respectively. The survival advantage experienced by females (17% lower risk of recurrences and 29% lower risk of cancer deaths) regarding other oral sites was independent from the effect of clinical factors.