Seroprevalence of hepatitis E virus in dromedary camels, Bedouins, Muslim Arabs and Jews in Israel, 2009-2017.

Hepatitis E virus (HEV) is an emerging cause of viral hepatitis worldwide. Recently, HEV-7 has been shown to infect camels and humans. We studied HEV seroprevalence in dromedary camels and among Bedouins, Arabs (Muslims, none-Bedouins) and Jews and assessed factors associated with anti-HEV seropositivity. Serum samples from dromedary camels (n = 86) were used to determine camel anti-HEV IgG and HEV RNA positivity. Human samples collected between 2009 and 2016 from >20 years old Bedouins (n = 305), non-Bedouin Arabs (n = 320) and Jews (n = 195), were randomly selected using an age-stratified sampling design. Human HEV IgG levels were determined using Wantai IgG ELISA assay. Of the samples obtained from camels, 68.6% were anti-HEV positive. Among the human populations, Bedouins and non-Bedouin Arabs had a significantly higher prevalence of HEV antibodies (21.6% and 15.0%, respectively) compared with the Jewish population (3.1%). Seropositivity increased significantly with age in all human populations, reaching 47.6% and 34.8% among ⩾40 years old, in Bedouins and non-Bedouin Arabs, respectively. The high seropositivity in camels and in ⩾40 years old Bedouins and non-Bedouin Arabs suggests that HEV is endemic in Israel. The low HEV seroprevalence in Jews could be attributed to higher socio-economic status.

The protective effects of melatonin against cryopreservation-induced oxidative stress in human sperm.

Reactive oxygen species (ROS) production and lipid peroxidation during cryopreservation harm sperm membrane and as a result reduce the recovery of motile sperm. The antioxidant effects of melatonin on different cells have been widely reported. This study was aimed to evaluate changes in post-thaw motility, viability, and intracellular ROS and malondialdehyde (MDA) in response to the addition of melatonin to human sperm freezing extender. Semen of 43 fertile men was collected and each sample was divided into eight equal aliquots. An aliquot was analyzed freshly for viability, motility, and intracellular ROS and MDA. Melatonin was added to the recommended human freezing extender to yield six different final concentrations: 0.001, 0.005, 0.01, 0.05, 0.1, and 1 mM. A control group without melatonin was also included. Two weeks after cryopreservation, samples were thawed and pre-freeze analyses repeated. Obtained results showed that cryopreservation significantly (P <0.05) reduces viability and motility, but increases intracellular ROS and MDA of human sperm. The semen extender supplemented with various doses of melatonin (except for 0.001 mM) significantly (P <0.05) increased motility and viability, but decreased intracellular ROS and MDA levels of cryopreserved sperm after the thawing process, as compared with the control group. We also found that the most effective concentration of melatonin in protecting human spermatozoa from cryopreservation injuries was 0.01 mM. These findings suggest that melatonin exerts its cryoprotective effects on spermatozoa possibly by counteracting intracellular ROS, and thereby reduces MDA generation. This finally leads to increase of post-thaw viability and motility of cryopreserved spermatozoa.

Modelling the erosive effects of sewer flushing using different sediment transport formulae.

A numerical investigation to simulate the cleaning effects of successive flushes over sediment beds in prismatic channels is presented in this paper. The 1D De Saint Venant-Exner equations were used to describe the temporal evolution of the sediment bed after each flush. The predictive capacity of two sediment transport formulae was explored against experimental results from laboratory tests. Results show that the adopted model can successfully describe the evolution of the sediment bed due to the flushes exerted during the experiments, with differences between the used transport formulae depending on the channel invert slope and on the flush energy.

Microstructural remodeling of articular cartilage following defect repair by osteochondral autograft transfer.

OBJECTIVE: To assess collagen network alterations occurring with flow and other abnormalities of articular cartilage at medial femoral condyle (MFC) sites repaired with osteochondral autograft (OATS) after 6 and 12 months, using quantitative polarized light microscopy (qPLM) and other histopathological methods. DESIGN: The collagen network structure of articular cartilage of OATS-repaired defects and non-operated contralateral control sites were compared by qPLM analysis of parallelism index (PI), orientation angle (α) relative to the local tissue axes, and retardance (Γ) as a function of depth. qPLM parameter maps were also compared to ICRS and Modified O'Driscoll grades, and cell and matrix sub-scores, for sections stained with H&E and Safranin-O, and for Collagen-I and II. RESULTS: Relative to non-operated normal cartilage, OATS-repaired regions exhibited structural deterioration, with low PI and more horizontal α, and unique structural alteration in adjacent host cartilage: more aligned superficial zone, and reoriented deep zone lateral to the graft, and matrix disorganization in cartilage overhanging the graft. Shifts in α and PI from normal site-specific values were correlated with histochemical abnormalities and co-localized with changes in cell organization/orientation, cloning, or loss, indicative of cartilage flow, remodeling, and deterioration, respectively. CONCLUSIONS: qPLM reveals a number of unique localized alterations of the collagen network in both adjacent host and implanted cartilage in OATS-repaired defects, associated with abnormal chondrocyte organization. These alterations are consistent with mechanobiological processes and the direction and magnitude of cartilage strain.

Role of cartilage collagen fibrils networks in knee joint biomechanics under compression.

Collagen fibrils networks in knee cartilage and menisci change in content and structure from a region to another. While resisting tension, they influence global joint response as well as local strains particularly at short-term periods. To investigate the role of fibrils networks in knee joint mechanics and in particular cartilage response, a novel model of the knee joint is developed that incorporates the cartilage and meniscus fibrils networks as well as depth-dependent properties in cartilage. The joint response under up to 2000N compression is investigated for conditions simulating the absence in cartilage of deep fibrils normal to subchondral bone or superficial fibrils parallel to surface as well as localized split of cartilage at subchondral junction or localized damage to superficial fibrils at loaded areas. Deep vertical fibrils network in cartilage play a crucial role in stiffening (by 10%) global response and protecting cartilage by reducing large strains (from maximum of 102% to 38%), in particular at subchondral junction. Superficial horizontal fibrils protect the tissue mainly from excessive strains at superficial layers (from 27% to 8%). Local cartilage split at base disrupts the normal function of vertical fibrils at the affected areas resulting in higher strains. Deep fibrils, and to a lesser extent superficial fibrils, play dominant mechanical roles in cartilage response under transient compression. Any treatment modality attempting to repair or regenerate cartilage defects involving partial or full thickness osteochondral grafts should account for the crucial role of collagen fibrils networks and the demanding mechanical environment of the tissue.

Investigation into the environmental fate of the combined Insensitive High Explosive constituents 2,4-dinitroanisole (DNAN), 1-nitroguanidine (NQ) and nitrotriazolone (NTO) in soil.

Contamination of military ranges by the use of explosives can lead to irreversible environmental damage, specifically to soil and groundwater. The fate and effects of traditional explosive residues are well understood, while less is known about the impact of Insensitive High Explosives (IHEs) that are currently being brought into military service. Current research has focussed on the investigation of individual constituents of IHE formulations, which may not be representative of real-world scenarios when explosive residues will be deposited together. Therefore, this study investigated the fate and transport of the combined IHE constituents 2,4-dinitroanisole (DNAN), 1-nitroguanidine (NQ) and 3-nitro-1,2,4-triazol-5-one (NTO) in two UK soil types. Static experiments ran for 9weeks to determine the fate of the combined explosive constituents in soil by monitoring the rate of degradation. Transport was examined by running soil column experiments for 5weeks, with a watering regime equivalent to the average yearly UK rainfall. Both static and soil column experiments confirmed that DNAN and NTO started to degrade within twenty-four hours in soil with high organic content, and were both completely degraded within sixty days. NQ was more stable, with 80% of the original material recovered after sixty days. The major degradation product of DNAN in the test soils was 2-amino-4-nitroanisole (2-ANAN), with trace amounts of 4-amino-2-nitroanisole. NTO was rapidly degraded in soil with high organic content, although no degradation products were identified. Results supported work from literature on the individual constituents DNAN, NQ and NTO suggesting that the three explosives in combination did not interact with each other when in soil. This study should provide a useful insight into the behaviour of three combined Insensitive High Explosive constituents for the predication of soil and water contamination during military training.

Epidemiology of tuberculosis among Afghan immigrants in Fars province, southern Islamic Republic of Iran.

Rates of tuberculosis are high among migrants from high-incidence countries. This study determined the epidemiology of tuberculosis among Afghan immigrants in Fars province, southern Islamic Republic of Iran. From April 2000 to April 2002, all records were examined for new tuberculosis patients of Afghan origin registered at Shiraz University of Medical Sciences. A total of 371 patients (208 males, 163 females) were found: 74.9% pulmonary and 25.1% extrapulmonary cases. Of the 278 new cases of pulmonary tuberculosis, 157 (56.5%) were sputum smear-positive and 121 (43.5%) were sputum smear-negative. The incidence of tuberculosis per 100 000 Afghan population in Fars province was estimated at 96.2, 88.2 and 63.5 in 2000, 2001 and 2002 respectively.

Analysis of articular cartilage as a composite using nonlinear membrane elements for collagen fibrils.

To develop a composite fibre-reinforced model of the cartilage, membrane shell elements were introduced to represent collagen fibrils reinforcing the isotropic porous solid matrix filled with fluid. Nonlinear stress-strain curve of pure collagen fibres and collagen volume fraction were explicitly presented in the formulation of these membrane elements. In this composite model, in accordance with tissue structure, the matrix and fibril membrane network experienced dissimilar stresses despite identical strains in the fibre directions. Different unconfined compression and indentation case studies were performed to determine the distinct role of membrane collagen fibrils in nonlinear poroelastic mechanics of articular cartilage. The importance of nonlinear fibril membrane elements in the tissue relaxation response as well as in temporal and spatial variations of pore pressure and solid matrix stresses was demonstrated. By individual adjustments of the collagen volume fraction and collagen mechanical properties, the model allows for the simulation of alterations in the fibril network structure of the tissue towards modelling damage processes or repair attempts. The current model, which is based on a physiological description of the tissue structure, is promising in improvement of our understanding of the cartilage pathomechanics.

Female genital tuberculosis and infertility.

OBJECTIVES: This study was performed to evaluate the rate of diagnosed female genital tuberculosis and its presentational symptoms and methods of diagnosis. METHODS: A total of 3088 cases of tuberculosis (TB) who had been registered and treated in the Health Center of Fars Province from 1989 to 1999 were retrospectively studied. From this group, 46 women were diagnosed as having genital TB. The diagnosis in 41 cases was based on the standard pathological criteria of tissue specimens. The other five cases were excluded from this study due to the lack of classical diagnostic criteria. Statistical analysis was performed using the Z-test. RESULTS: The mean age of the patients at the time of diagnosis was 30.4 years. Seven patients presented with abdominal or pelvic pain (17.07%). In this group three cases underwent laparatomy due to abdominal mass and four patients for tubo-ovarian abscess, which led to the diagnosis. Abnormal uterine bleeding was the cause of diagnostic dilatation and curettage in three other patients (7.31%). However, in 31 cases (75.6%) TB was diagnosed during studies performed to evaluate the cause of their infertility, and the most common diagnostic procedure was endometrial curettage (25 cases). Female genital TB accounted for 1.32% of all tuberculous patients in this study. Of these, 75.6% were infertile by definition (Z=12.13 P<0.0001). TB endometritis was detected in 72.03%, tubal involvement in 34.03%, ovarian TB in 12.9% and cervical TB in 2.4% of the patients. CONCLUSIONS: This study confirms the presence of a strong relationship between genital TB and infertility; therefore genital TB would be more frequently diagnosed if this possibility was considered in the evaluation of every infertile patient in areas where tuberculosis is endemic.

Computational biodynamics of human knee joint in gait: from muscle forces to cartilage stresses.

Using a validated finite element model of the intact knee joint we aim to compute muscle forces and joint response in the stance phase of gait. The model is driven by reported in vivo kinematics-kinetics data and ground reaction forces in asymptomatic subjects. Cartilage layers and menisci are simulated as depth-dependent tissues with collagen fibril networks. A simplified model with less refined mesh and isotropic depth-independent cartilage is also considered to investigate the effect of model accuracy on results. Muscle forces and joint detailed response are computed following an iterative procedure yielding results that satisfy kinematics/kinetics constraints while accounting at deformed configurations for muscle forces and passive properties. Predictions confirm that muscle forces and joint response alter substantially during the stance phase and that a simplified joint model may accurately be used to estimate muscle forces but not necessarily contact forces/areas, tissue stresses/strains, and ligament forces. Predictions are in general agreement with results of earlier studies. Performing the analyses at 6 periods from beginning to the end (0%, 5%, 25%, 50%, 75% and 100%), hamstrings forces peaked at 5%, quadriceps forces at 25% whereas gastrocnemius forces at 75%. ACL Force reached its maximum of 343 N at 25% and decreased thereafter. Contact forces reached maximum at 5%, 25% and 75% periods with the medial compartment carrying a major portion of load and experiencing larger relative movements and cartilage strains. Much smaller contact stresses were computed at the patellofemoral joint. This novel iterative kinematics-driven model is promising for the joint analysis in altered conditions.

Chest wall involvement as a manifestation of brucellosis.

Brucellosis continues to be a common infectious disease in some parts of the world. Although the disease has different presentations, but chest wall involvement, as a manifestation of brucellosis is rare. In this study, we report three cases of chest wall involvement as manifesting feature of Brucellosis in Iran. They presented with a history of parasternal masses revealed to a diagnosis of Brucellosis and responded well to the treatment. Brucellosis may present with strange and unpredictable manifestations and can be misdiagnosed with tuberculosis and malignancies, especially in endemic areas for both TB and brucellosis.

Computational biomechanics of articular cartilage of human knee joint: effect of osteochondral defects.

Articular cartilage and its supporting bone functional conditions are tightly coupled as injuries of either adversely affects joint mechanical environment. The objective of this study was set to quantitatively investigate the extent of alterations in the mechanical environment of cartilage and knee joint in presence of commonly observed osteochondral defects. An existing validated finite element model of a knee joint was used to construct a refined model of the tibial lateral compartment including proximal tibial bony structures. The response was computed under compression forces up to 2000 N while simulating localized bone damage, cartilage-bone horizontal split, bone overgrowth and absence of deep vertical collagen fibrils. Localized tibial bone damage increased overall joint compliance and substantially altered pattern and magnitude of contact pressures and cartilage strains in both tibia and femur. These alterations were further exacerbated when bone damage was combined with base cartilage split and absence of deep vertical collagen fibrils. Local bone boss markedly changed contact pressures and strain patterns in neighbouring cartilage. Bone bruise/fracture and overgrowth adversely perturbed the homeostatic balance in the mechanical environment of articulate cartilage surrounding and opposing the lesion as well as the joint compliance. As such, they potentially contribute to the initiation and development of post-traumatic osteoarthritis.

Analysis of partial meniscectomy and ACL reconstruction in knee joint biomechanics under a combined loading.

BACKGROUND: Despite partial meniscectomies and ligament reconstructions as treatments of choice for meniscal and ligament injuries, respectively, the knee joint osteoarthritis persists. METHODS: A detailed nonlinear finite element model of the knee joint was developed to evaluate biomechanics of the tibiofemoral joint under 200 N drawer load with and without 1500 N compression preload. The model incorporated composite structure of cartilage and meniscus. The effects on joint response and articular contact pressure of unilateral partial meniscectomy, of changes in prestrain or material properties of the anterior cruciate ligament and of their combination were investigated. FINDINGS: Compressive preload further increases anterior cruciate ligament strains/forces in drawer loading. Partial meniscectomy and perturbations in anterior cruciate ligament prestrain/material properties, alone or combined, substantially alter the load transfer via covered and uncovered areas of cartilage as well as contact pressure distribution on cartilage. Partial meniscectomy especially when combined with a slacker anterior cruciate ligament diminish the load via affected meniscus generating unloaded regions on the cartilage. INTERPRETATION: Partial meniscectomy concurrent with a slack anterior cruciate ligament substantially alter cartilage contact pressures. These alterations further intensify in the event of greater external forces, larger meniscal resections and total anterior cruciate ligament rupture, thus suggesting a higher risk of joint degeneration.

Deep vertical collagen fibrils play a significant role in mechanics of articular cartilage.

The primary orientation of collagen fibrils alters along the cartilage depth; being horizontal in the superficial zone, random in the transitional zone, and vertical in the deep zone. Commonly used confined and unconfined (when with no underlying bone) testing configurations cannot capture the mechanical role of deep vertical fibril network. To determine this role in cartilage mechanics, an axisymmetric nonlinear fibril-reinforced poroelastic model of tibial cartilage plateaus was developed accounting for depth-dependent properties and distinct fibril networks with physical material properties. Both creep and relaxation indentation models were analyzed which results were found equivalent in the transient period but diverged in post-transient periods. Vertical fibrils played a significant role at the transient period in dramatically increasing the stiffness of the tissue and in protecting the solid matrix against large distortions and strains at the subchondral junction. This role, however, disappeared both with time and at loading rates slower than those expected in physiological activities such as walking. The vertical fibrils demonstrated a chevron-type deformation pattern that was further accentuated with time in creep loading. Damages to deep vertical collagen fibril network or their firm anchorage to the bone, associated with bone bruises, for example, would weaken the transient stiffness and place the tissue at higher risk of failure particularly at the deep zone.

A computer model to assess continuity of care.

The implementation of continuity of care recommended in Changing Childbirth has not been easy and in practice varies from hospital to hospital. A computer model being developed at St Thomas' Hospital, allows users to consider the implications of different scenarios, for example: -different midwives' rotas -different caseloads per midwife -size of the team if team midwifery is being implemented. This model can be used to identify the benefits and disadvantages of different policies for both the midwives and the women in their care.

Epidemiology of tuberculosis among Afghan immigrants in Fars province, southern Islamic Republic of Iran

Rates of tuberculosis are high among migrants from high-incidence countries. This study determined the epidemiology of tuberculosis among Afghan immigrants in Fars province, southern Islamic Republic of Iran. From April 2000 to April 2002, all records were examined for new tuberculosis patients of Afghan origin registered at Shiraz University of Medical Sciences. A total of 371 patients [208 males, 163 females] were found: 74.9% pulmonary and 25.1% extrapulmonary cases. Of the 278 new cases of pulmonary tuberculosis, 157 [56.5%] were sputum smear-positive and 121 [43.5%] were sputum smear-negative. The incidence of tuberculosis per 100 000 Afghan population in Fars province was estimated at 96.2, 88.2 and 63.5 in 2000, 2001 and 2002 respectively