ABSTRACT
Peste des petits ruminants virus (PPRV) causes a contagious disease of high morbidity and mortality in global sheep and goat populations. To better control this disease and inform eradication strategies, an improved understanding of how PPRV transmission risk varies by age is needed. Our study used a piece-wise catalytic model to estimate the age-specific force of infection (FOI, per capita infection rate of susceptible hosts) among sheep, goats, and cattle from a cross-sectional serosurvey dataset collected in 2016 in Tanzania. Apparent seroprevalence increased with age, reaching 53.6%, 46.8%, and 11.6% (true seroprevalence: 52.7%, 52.8%, 39.2%) for sheep, goats, and cattle, respectively. Seroprevalence was significantly higher among pastoral animals than agropastoral animals across all ages, with pastoral sheep and goat seroprevalence approaching 70% and 80%, respectively, suggesting pastoral endemicity. The best fitting piece-wise catalytic models merged age groups: two for sheep, three for goats, and four for cattle. The signal of these age heterogeneities were weak, except for a significant FOI peak among 2.5-3.5-year-old pastoral cattle. The subtle age-specific heterogeneities identified in this study suggest that targeting control efforts by age may not be as effective as targeting by other risk factors, such as production system type. Further research should investigate how specific husbandry practices affect PPRV transmission.
Subject(s)
Peste-des-Petits-Ruminants/epidemiology , Peste-des-Petits-Ruminants/transmission , Peste-des-petits-ruminants virus/genetics , Age Factors , Animals , Cattle , Cattle Diseases/epidemiology , Cattle Diseases/virology , Cohort Studies , Female , Goat Diseases/epidemiology , Goat Diseases/virology , Goats , Male , Peste-des-petits-ruminants virus/immunology , Seroepidemiologic Studies , Sheep , Sheep Diseases/epidemiology , Sheep Diseases/virology , Tanzania/epidemiologyABSTRACT
Peste des petits ruminants virus (PPRV) causes a contagious disease of high morbidity and mortality in small ruminant populations globally. Using cross-sectional serosurvey data collected in 2016, our study investigated PPRV seroprevalence and risk factors among sheep, goats and cattle in 20 agropastoral (AP) and pastoral (P) villages in northern Tanzania. Overall observed seroprevalence was 21.1% (95% exact confidence interval (CI) 20.1-22.0) with 5.8% seroprevalence among agropastoral (95% CI 5.0-6.7) and 30.7% among pastoral villages (95% CI 29.3-32.0). Seropositivity varied significantly by management (production) system. Our study applied the catalytic framework to estimate the force of infection. The associated reproductive numbers (R0) were estimated at 1.36 (95% CI 1.32-1.39), 1.40 (95% CI 1.37-1.44) and 1.13 (95% CI 1.11-1.14) for sheep, goats and cattle, respectively. For sheep and goats, these R0 values are likely underestimates due to infection-associated mortality. Spatial heterogeneity in risk among pairs of species across 20 villages was significantly positively correlated (R2: 0.59-0.69), suggesting either cross-species transmission or common, external risk factors affecting all species. The non-negligible seroconversion in cattle may represent spillover or cattle-to-cattle transmission and must be investigated further to understand the role of cattle in PPRV transmission ahead of upcoming eradication efforts.
Subject(s)
Disease Transmission, Infectious/statistics & numerical data , Goat Diseases/epidemiology , Peste-des-Petits-Ruminants/epidemiology , Peste-des-petits-ruminants virus/isolation & purification , Sheep Diseases/epidemiology , Agriculture , Animals , Cattle , Cross-Sectional Studies , Developing Countries , Goats , Humans , Incidence , Peste-des-Petits-Ruminants/diagnosis , Retrospective Studies , Risk Assessment , Seroepidemiologic Studies , Sheep , Tanzania/epidemiologyABSTRACT
INTRODUCTION: This guideline establishes clinical practice recommendations for the diagnosis of obstructive sleep apnea (OSA) in adults and is intended for use in conjunction with other American Academy of Sleep Medicine (AASM) guidelines on the evaluation and treatment of sleep-disordered breathing in adults. METHODS: The AASM commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) process was used to assess the evidence. The task force developed recommendations and assigned strengths based on the quality of evidence, the balance of benefits and harms, patient values and preferences, and resource use. In addition, the task force adopted foundational recommendations from prior guidelines as "good practice statements", that establish the basis for appropriate and effective diagnosis of OSA. The AASM Board of Directors approved the final recommendations. RECOMMENDATIONS: The following recommendations are intended as a guide for clinicians diagnosing OSA in adults. Under GRADE, a STRONG recommendation is one that clinicians should follow under most circumstances. A WEAK recommendation reflects a lower degree of certainty regarding the outcome and appropriateness of the patient-care strategy for all patients. The ultimate judgment regarding propriety of any specific care must be made by the clinician in light of the individual circumstances presented by the patient, available diagnostic tools, accessible treatment options, and resources. Good Practice Statements: Diagnostic testing for OSA should be performed in conjunction with a comprehensive sleep evaluation and adequate follow-up. Polysomnography is the standard diagnostic test for the diagnosis of OSA in adult patients in whom there is a concern for OSA based on a comprehensive sleep evaluation.Recommendations: We recommend that clinical tools, questionnaires and prediction algorithms not be used to diagnose OSA in adults, in the absence of polysomnography or home sleep apnea testing. (STRONG). We recommend that polysomnography, or home sleep apnea testing with a technically adequate device, be used for the diagnosis of OSA in uncomplicated adult patients presenting with signs and symptoms that indicate an increased risk of moderate to severe OSA. (STRONG). We recommend that if a single home sleep apnea test is negative, inconclusive, or technically inadequate, polysomnography be performed for the diagnosis of OSA. (STRONG). We recommend that polysomnography, rather than home sleep apnea testing, be used for the diagnosis of OSA in patients with significant cardiorespiratory disease, potential respiratory muscle weakness due to neuromuscular condition, awake hypoventilation or suspicion of sleep related hypoventilation, chronic opioid medication use, history of stroke or severe insomnia. (STRONG). We suggest that, if clinically appropriate, a split-night diagnostic protocol, rather than a full-night diagnostic protocol for polysomnography be used for the diagnosis of OSA. (WEAK). We suggest that when the initial polysomnogram is negative and clinical suspicion for OSA remains, a second polysomnogram be considered for the diagnosis of OSA. (WEAK).
Subject(s)
Humans , Adult , Polysomnography/methods , Sleep Apnea, Obstructive/diagnosis , Sleep Medicine Specialty/methods , GRADE ApproachABSTRACT
Defining genetic diversity in the wake of the release of several Mycobacterium avium subsp. paratuberculosis (MAP) genome sequences has become a major emphasis in the molecular biology and epidemiology of Johne's disease research. These data can now be used to define the extent of strain diversity on the farm. However, to perform these important tasks, researchers must have a way to distinguish the many MAP isolates/strains that are present in the environment or host to enable tracking over time. Recent studies have described genetic diversity of the Mycobacterium avium complex (MAC), of which MAP is a member, through pulsed-field gel electrophoresis, single sequence repeats, variable-number tandem repeats, genome rearrangements, single nucleotide polymorphisms and genomewide comparisons to identify insertions and deletions. Combinations of these methods can now provide discrimination sufficient for dependable strain tracking. These molecular epidemiology techniques are being applied to understand transmission of Johne's disease within dairy cattle herds as well as identify which strains predominate in wildlife.
Subject(s)
Bacterial Typing Techniques/methods , Genetic Variation , Molecular Epidemiology/methods , Mycobacterium avium subsp. paratuberculosis/genetics , Animals , Cattle , Electrophoresis, Gel, Pulsed-Field , Gene Rearrangement , Genome, Bacterial , Microsatellite Repeats , Minisatellite Repeats , Mycobacterium avium subsp. paratuberculosis/classification , Paratuberculosis/microbiology , Polymorphism, Single Nucleotide , SheepABSTRACT
A common metric of assessing the evaporative cooling potential of protective clothing is to assess the rate of diffusion of water vapour through the fabric. Another mechanism that supports evaporative cooling is convective transfer. Prototype porous coveralls were constructed to promote convective air flow with 0.0024 mm (0.06 inch) holes representing nominal openings of 0, 1, 2, 5, 10 and 20% of the garment surface area (called P00, P01, P02, P05, P10 and P20). The purpose of this study was to evaluate the ability of these porous coverall configurations to support evaporative cooling. The assessment measures were critical wet bulb globe temperature (WBGT) and apparent evaporative resistance via a progressive heat stress protocol. There was a progressive increase in critical WBGT with increases in convective permeability for P00, Saratoga Hammer, P01, work clothes and P02. There was no further increase for P05, P10 and P20. A similar pattern was found for diffusive permeability, with the exception of Saratoga Hammer, which suggested that the convective permeability could explain evaporative cooling better than diffusive permeability. STATEMENT OF RELEVANCE: Protective clothing often interferes with evaporative cooling and thus increases the level of heat stress. While increased diffusion of water vapour is associated with lower evaporative resistances, the convective movement of water vapour is a dominant mechanism and better explains the role of the clothing in heat stress.
Subject(s)
Heat Stress Disorders/prevention & control , Protective Clothing/standards , Adult , Convection , Humans , Male , Porosity , Young AdultABSTRACT
Sexual dysfunction is a common problem of increasing incidence that is associated with multiple co-morbid conditions and chronic diseases. In heart failure, however, exact numbers are unknown, in part secondary to under-reporting and under-interrogating by health care providers. A gender-specific questionnaire was modified from established sexual dysfunction questionnaires to correspond to a non-randomized outpatient heart failure population, to assess the prevalence and demographic distribution of sexual dysfunction and potential treatments expectations. One-hundred patients in a stable hemodynamic condition in New York Heart Association classes I-III participated. Eighty-seven percent of women were diagnosed with female sexual dysfunction compared to 84% of men with erectile dysfunction. Eighty percent of women reported reduced lubrication, which resulted in frequent unsuccessful intercourse in 76%. Thirty-six percent of patients thought that sexual activity could harm their current cardiac condition; 75% of females and 60% of men stated that no physicians ever asked about potential sexual problems. Fifty-two percent of men considered sexual activity in their current condition as an essential aspect of quality of life and 61% were interested in treatment to improve sexual function. Sexual dysfunction appears to be high in prevalence in both men and women with chronic compensated heart failure and represents a reduction in quality of life for most. Despite the fact that most patients are interested in receiving therapy to improve sexual dysfunction, treatment options are rarely discussed or initiated.
Subject(s)
Erectile Dysfunction/epidemiology , Heart Failure/complications , Sexual Dysfunction, Physiological/complications , Sexual Dysfunction, Physiological/epidemiology , Chronic Disease , Female , Humans , Male , Prevalence , Quality of Life , Sex Factors , Surveys and QuestionnairesABSTRACT
OBJECTIVES: To characterize the acute response of the vein wall to venous hypertension and associated altered fluid shear stress and to test the effect of micronized purified flavonoid fraction (MPFF, Daflon 500), on this response. MATERIAL AND METHODS: A femoral arteriovenous fistula was created in Wistar rats (n=48). A cohort of 24 rats received oral treatment with MPFF (100 mg/kg/day body weight), 24 rats underwent the arteriovenous fistula procedure and received no treatment. At days 1, 7 and 21 the animals (n=8 at each time point) were killed. Experimental parameters measured included limb circumference, blood flow at the sapheno-femoral junction, leukocyte infiltration and gelatinase activity (matrix metalloproteinase, MMP). RESULTS: The acute rise in venous hypertension was accompanied by limb edema and venous reflux together with an eventual loss of valve leaflets in the saphenous vein. There was an increase in granulocyte and macrophage infiltration into the venous wall and the surrounding tissue, and a lesser increase in T- and B-lymphocyte infiltration. These changes were accompanied by a local increase in the proteolytic enzymes, MMP-2 and MMP-9. Administration of MPFF reduced the edema and lessened the venous reflux produced by the acute arteriovenous fistula. Decreased levels of granulocyte and macrophage infiltration into the valves were also observed compared with untreated animals. CONCLUSIONS: Venous hypertension caused by an arteriovenous fistula resulted in the development of venous reflux and an inflammatory reaction in venous valves culminating in their destruction. MPFF was able to delay the development of reflux and suppress damage to the valve structures in this rat model of venous hypertension.
Subject(s)
Cardiovascular Agents/pharmacology , Diosmin/pharmacology , Femoral Vein/drug effects , Saphenous Vein/drug effects , Venous Insufficiency/drug therapy , Venous Pressure/drug effects , Animals , Arteriovenous Shunt, Surgical , Blood Flow Velocity , Cardiovascular Agents/therapeutic use , Chemotaxis, Leukocyte/drug effects , Diosmin/therapeutic use , Disease Models, Animal , Edema/etiology , Edema/physiopathology , Edema/prevention & control , Femoral Artery/surgery , Femoral Vein/enzymology , Femoral Vein/pathology , Femoral Vein/physiopathology , Femoral Vein/surgery , Granulocytes/drug effects , Granulocytes/pathology , Lymphocytes/drug effects , Lymphocytes/pathology , Macrophages/drug effects , Macrophages/pathology , Male , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 9/metabolism , Rats , Rats, Wistar , Regional Blood Flow , Saphenous Vein/enzymology , Saphenous Vein/pathology , Saphenous Vein/physiopathology , Stress, Mechanical , Time Factors , Venous Insufficiency/complications , Venous Insufficiency/enzymology , Venous Insufficiency/pathology , Venous Insufficiency/physiopathologyABSTRACT
Phosphodiesterase-5 (PDE-5) inhibitors selectively inhibit PDE-5 enzymes that are present in various tissues like penile tissue, platelets, vascular, and smooth muscle tissue. The drug's actions on these tissues have lead to the successful therapeutic use in patients suffering from conditions such as erectile dysfunction (ED) and pulmonary hypertension. PDE-5 inhibitors (PDE-5i) act on the erectile tissue causing penile smooth muscle relaxation and vasodilatation leading to penile erection. In addition, in particular when used in conjunction with prostaglandin inhibitors, PDE-5i cause vasodilatation in pulmonary vasculature hence decreasing both the pulmonary arterial pressure and resistance. PDE-5i have also shown to mildly decrease blood pressure, increase cardiac index, and increase coronary blood flow in experimental animals as well as in human studies. The Food and Drug Administration (FDA) has approved three PDE-5i for the treatment of ED: sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis) and one for pulmonary hypertension: sildenafil (Revatio). These agents are highly selective for PDE-5 enzymes as compared to other subclasses of PDE enzymes and have the almost identical pharmacological action but slightly different pharmacokinetics. Only little data exist about long-term use of PDE-5i and their effects on different organ system. This paper reviews the current information available on chronic PDE-5 inhibitor use.
Subject(s)
3',5'-Cyclic-GMP Phosphodiesterases/antagonists & inhibitors , Erectile Dysfunction/drug therapy , Phosphodiesterase Inhibitors/adverse effects , Phosphodiesterase Inhibitors/therapeutic use , Age Factors , Animals , Blood Platelets/drug effects , Cerebrovascular Circulation/drug effects , Erectile Dysfunction/etiology , Gastrointestinal Tract/drug effects , Heart/drug effects , Humans , Lung/drug effects , Male , Myocardial Ischemia/complications , Myocardial Ischemia/drug therapyABSTRACT
The present case report describes the topographical anatomy and radiological study of an asymmetrical inferior articular process of a lumbar vertebra, which was detected during routine osteology teaching of undergraduate medical students. The inferior articular process of the lumbar vertebra on the left side was rudimentary, while that on the right was normal in size. On the left side an additional bony projection was noted anterior to the rudimentary inferior articular process. The difference in height between the inferior articular processes of the two sides may play an important role in the kinematics of the particular joint. The orientation of the facets of the articular processes of the vertebrae are important for axial weight transmission and anomalies involving these can possibly alter the orientation of movements in that particular segment. An asymmetrical inferior articular process may be related to disc prolapse and may be a cause of back pain. In view of the paucity of research reports of anatomicoradiological study of the inferior articular process of a lumbar vertebra in relation to other parts of the vertebra, we, as anatomists, believe that knowledge of anomalies of the inferior articular process may be relevant for academic, anthropological and clinical purposes.
Subject(s)
Lumbar Vertebrae/abnormalities , Cadaver , Genetic Variation , Humans , Lumbar Vertebrae/diagnostic imaging , RadiographyABSTRACT
The obturator foramen is a large opening in the hip bone situated below and anterior to the acetabulum. The obturator foramen is enclosed by the obturator membrane, apart from the part above near the obturator groove, where the obturator vessels and nerve pass through. The present study reports multiple openings in the obturator foramen detected incidentally in a left hip bone specimen and discusses its clinical implications. To the best of our knowledge, the occurrence of multiple openings associated with the obturator foramen is rare and has not been reported in any standard textbook of anatomy or in any research study. Anatomical knowledge of the presence of such anomalies may be clinically important for radiologists interpreting skiagrams and surgeons performing operative procedures in the hip region.
Subject(s)
Pelvic Bones/abnormalities , Humans , Pelvic Bones/diagnostic imaging , RadiographyABSTRACT
Anterior arch of the atlas vertebra is known to exhibit various developmental anomalies. Bony outgrowths, osteophytes, clefts and aplasia of the anterior and posterior arches of the atlas have received special attention by research workers. To the best of our knowledge, not many osteological studies have defined the spicules on the anterior arch of the atlas. The present study describes an abnormal atlas vertebra with 2 spicules on the inferior aspect, 2 additional facets inferior to the superior articular facets and a peculiar facet to the left of the posterior tubercle. These abnormal spicules may cause dysphagia or involve atlanto-occipital movements. Such anomalies may be misinterpreted in routine X rays as a degenerative disease. However, asymptomatic cases remain undetected throughout life. Such anomalies may be important in radiological, clinical, forensic and anthropological studies.
Subject(s)
Cervical Atlas/abnormalities , Musculoskeletal Abnormalities/diagnosis , Cadaver , Cervical Atlas/diagnostic imaging , Humans , Musculoskeletal Abnormalities/diagnostic imaging , RadiographyABSTRACT
Microglia, the resident macrophages in the central nervous system (CNS), play a pivotal role in innate and adaptive immune responses in the brain. The immune functions of microglia are regulated by cytokines, including interferon (IFN)-gamma, which is a major mediator of macrophage activation. We describe the transcriptional profile of human fetal microglial cells at 1, 6, and 24 h after IFN-gamma treatment. The results show a change in the expression of 405 genes including transcriptionally induced chemokines, IFN-gamma signaling factors, and major histocompatibility complex genes. Our results demonstrate that activation of microglia by IFN-gamma induces proinflammatory T-lymphocyte-related chemokine genes as well as genes involved in antigen presentation. As a result, signals for T-cell infiltration and antigen presentation are produced to allow for microglia-T-cell interactions that likely contribute to defense against invading pathogens. In sum, our results provide a foundation for the molecular mechanisms of the microglial response to IFN-gamma-a key to understanding cell-mediated immunity of the CNS.
Subject(s)
Interferon-gamma/pharmacology , Microglia/drug effects , Transcription, Genetic/drug effects , Cells, Cultured , Chemokine CCL2/metabolism , Chemokine CCL5 , Chemokine CXCL10 , Chemokine CXCL11 , Chemokines/analysis , Chemokines, CC/metabolism , Chemokines, CXC/metabolism , Culture Media/chemistry , Cytokines/analysis , Fetus , Gene Expression , Humans , Interferon-gamma/genetics , Kinetics , Microglia/immunology , Models, Genetic , RNA, Messenger/analysis , Recombinant Proteins/pharmacology , Time FactorsABSTRACT
Chronic heart failure (HF) is an increasingly common cardiovascular disorder. The goal of health-care providers is to optimize quality of life in this population, including sexual health. Up to 75% of patients with HF report erectile dysfunction (ED). As HF is a condition with distinct physiologic sequelae, some unique organic and psychological factors contributing to ED in this patient population have been identified, along with risk factors common to the development of coronary artery disease, HF and ED. This review describes contributing factors to ED in the setting of HF and highlights treatment considerations for this distinct patient population.
Subject(s)
Erectile Dysfunction/etiology , Erectile Dysfunction/therapy , Heart Failure/complications , Heart Failure/drug therapy , Adrenergic beta-Antagonists/therapeutic use , Angioplasty, Balloon , Depression/drug therapy , Digoxin/therapeutic use , Diuretics/therapeutic use , Endothelium, Vascular/physiopathology , Erectile Dysfunction/psychology , Exercise , Heart Failure/psychology , Humans , Male , Piperazines/therapeutic use , Purines , Sexual Behavior , Sildenafil Citrate , SulfonesABSTRACT
Erectile dysfunction (ED) is increasingly considered as one manifestation of systemic vascular disease. Accordingly, ED and coronary artery disease share mutual risk factors and frequently coexist. Sexual health is an important aspect of our patients' lives, and ED is a common concern of the cardiovascular patient. Despite this, sexual function is under-addressed in the cardiac patient. Even when this topic is broached by the primary care physician or urologist, ED frequently remains untreated due to safety concerns involving cardiac disease and other comorbidities. This article describes our experience with this unique patient population, as well as our approach to building a multidisciplinary clinic designed to specifically address the important issue of ED in the cardiac patient.
Subject(s)
Cardiovascular Diseases/complications , Erectile Dysfunction/etiology , Erectile Dysfunction/therapy , Administration, Oral , Cardiovascular Diseases/drug therapy , Erectile Dysfunction/drug therapy , Humans , Male , Phosphodiesterase Inhibitors/administration & dosage , Risk Factors , Sexual BehaviorABSTRACT
Median nerve and brachial artery in the arm are not usually overlapped by any structure. Connective tissue bands and muscular slips draping or enclosing this neurovascular bundle have been reported, however, which may produce clinical symptoms of nerve compression and vascular changes. We report an unusual musculoaponeurotic band that originates as the ligament of Struthers but terminates as the brachiofascialis muscle of Wood and in the process may have entrapped both the median nerve and brachial artery. The nerve to pronator teres originates from the median nerve within this tunnel. On histological examination the nerve was flattened and showed some perineurial thickening. In view of the flexor function of brachialis muscle, this anomalous musculoaponeurotic band may be considered a clinically important entity in the causation of idiopathic neurovasculopathy in the hand.
Subject(s)
Brachial Artery/abnormalities , Median Nerve/abnormalities , Nerve Compression Syndromes/etiology , Brachial Artery/anatomy & histology , Cadaver , Humans , Male , Median Nerve/anatomy & histology , Middle AgedABSTRACT
STUDY DESIGN: Retrospective case series. OBJECTIVES: Respiratory disorders are the leading cause of death in persons with spinal cord injury (SCI), but the epidemiology and medical management of pneumonia in persons with chronic SCI is not well characterized. We describe the clinical presentation of persons with SCI with community-acquired pneumonia (CAP), characterize its management and compare practice to recommendations for CAP in the general population. SETTING: Three United States Veterans Affairs Medical Centers with specialized SCI services. METHODS: Chart abstraction was performed for all persons with chronic SCI seen at participating centers for treatment of CAP during a 2-year period. Collected data included presenting signs and symptoms, laboratory and imaging results, initial antibiotic therapy, secretion mobilization techniques, in-patient vs outpatient management, length of stay, and mortality. RESULTS: In all, 41 persons with SCI received treatment for CAP during the study period. A total of 32 (78.0%) patients were admitted for treatment; two (4.8%) required intubation and mechanical ventilation. Initial antibiotic coverage met guideline recommendations for only half of inpatients and infrequently provided adequate antipseudomonal coverage. Microbiologic testing was performed on 26 cases (63.4%) and demonstrated a specific pathogen in only five cases (12.2% of total). Three cases (7.3%) died during treatment for CAP, and 16 (42.1%) of 38 CAP survivors died within a median follow-up of 3 years. CONCLUSION: The majority of chronic SCI patients who present to specialized SCI centers with CAP are admitted for treatment. Short-term mortality is comparable to CAP in the general population.
Subject(s)
Pneumonia/microbiology , Pneumonia/therapy , Spinal Cord Injuries/physiopathology , Adult , Aged , Anti-Bacterial Agents/therapeutic use , Community-Acquired Infections/microbiology , Community-Acquired Infections/mortality , Community-Acquired Infections/therapy , Diagnosis, Differential , Female , Hospital Units/statistics & numerical data , Hospitals, Veterans/statistics & numerical data , Humans , Male , Middle Aged , Pneumonia/mortality , Practice Guidelines as Topic , Pseudomonas Infections/diagnosis , Pseudomonas Infections/therapy , Retrospective Studies , Spinal Cord Injuries/complications , United StatesABSTRACT
Respiratory tract diseases are the single most important cause of economic loss due to infections among poultry populations worldwide. However, the molecular mechanisms of the host response to infections remain unknown. Here, we review the literature and describe the adoption of a conceptually simple approach to understand the genetic and biochemical responses of host cells during infection with respiratory pathogens, such as avian pneumovirus (APV). The strategy that we have adopted integrates the powerful techniques of cDNA subtraction hybridization and microarray analysis for global transcriptional profiling. The results of our investigations identify the specific transcriptional alterations in host-cell gene expression that result from an attempt by the host to combat and limit the spread of the pathogen or by the pathogen to enhance its own survival and ability to reproduce. Our studies suggest that a molecular description of host-pathogen interactions in terms of differential gene expression will provide key insights on the molecular basis of disease pathogenesis, pathogen virulence, and host immunity. In addition, the results suggest that the identification of genes and pathways with a role in host response to infection has considerable practical implications for the future design and development of effective immunomodulators and vaccines.
Subject(s)
Gene Expression Regulation , Oligonucleotide Array Sequence Analysis , Poultry Diseases/genetics , Respiratory Tract Diseases/veterinary , Transcription, Genetic , Animals , DNA, Complementary , In Situ Hybridization , Pneumovirus/pathogenicity , Pneumovirus Infections/genetics , Pneumovirus Infections/veterinary , Poultry , Respiratory Tract Diseases/genetics , Respiratory Tract Diseases/virology , VirulenceABSTRACT
Preliminary analysis of a partial (30% coverage) genome sequence of Rhodococcus equi has revealed a number of important features. The most notable was the extent of the homology of genes identified with those of Mycobacterium tuberculosis. The similarities in the proportion of genes devoted to fatty acid degradation and to lipid biosynthesis was a striking but not surprising finding given the relatedness of these organisms and their success as intracellular pathogens. The rapid recent improvement in understanding of virulence in M. tuberculosis and other pathogenic mycobacteria has identified a large number of genes of putative or proven importance in virulence, homologs of many of which were also identified in R. equi. Although R. equi appears to have currently unique genes, and has important differences, its similarity to M. tuberculosis supports the need to understand the basis of virulence in this organism. The partial genome sequence will be a resource for workers interested in R. equi until such time as a full genome sequence has been characterized.
Subject(s)
DNA, Bacterial/chemistry , Genome, Bacterial , Rhodococcus equi/genetics , Aerobiosis/genetics , Amino Acids/metabolism , Anaerobiosis/genetics , Animals , Base Sequence , Carbon/metabolism , Drug Resistance, Bacterial/genetics , Energy Metabolism/genetics , Enzymes/genetics , Fatty Acids/metabolism , Horses , Humans , Immunocompromised Host , Lipids/biosynthesis , Mycobacterium tuberculosis/enzymology , Mycobacterium tuberculosis/genetics , Mycobacterium tuberculosis/metabolism , Rhodococcus equi/enzymology , Rhodococcus equi/pathogenicity , Sequence Analysis, DNA/veterinary , Sequence Homology, Nucleic Acid , Virulence/geneticsABSTRACT
Rhinoceroses are highly endangered species and their protection warrants immediate remedial measures. Development of DNA markers is envisaged to complement global efforts of the conservation of these extant animals. Minisatellite associated sequence amplification (MASA) of DNA from Indian rhinoceros (Rhinoceros unicornis) and three sub-species of South African black rhinoceros (Diceros bicornis) was carried out using a primer based on consensus sequence of the minisatellite repeat locus 33.15. Several bands in the range of 3.0 kilobases (kb) to 650 base pairs (bp) were identified that were useful for successful differentiation of R. unicornis from D. bicornis. Of these fragments, a 688 bp one, unique to R. unicornis was cloned and sequenced (Accession No. AF-296689). The band patterns uncovered by MASA and the species-specific hybridisation of pSG5 may be utilised as a tool for differentiating the R. unicornis genome from that of D. bicornis. This approach may also be adopted for the development of DNA-based genetic marker(s) useful for identification of other endangered species.
Subject(s)
Minisatellite Repeats , Nucleic Acid Amplification Techniques , Perissodactyla/genetics , Animals , Base Sequence , Cloning, Molecular , Consensus Sequence , Genetic Markers , Molecular Sequence Data , South AfricaABSTRACT
We cloned and sequenced a 1378 bp BamHI satellite DNA fraction from the water buffalo Bubalus bubalis and have studied its expression in different tissues. The GC-rich sequences of the resultant contig pDS5 crosshybridize only with bovid DNA and are not conserved evolutionarily. Typing of buffalo genomic DNA using pDS5 with several restriction enzymes revealed multilocus monomorphic bands. Similar typing of cattle, buffalo, goat, sheep, and gaur genomic DNA revealed variations in copy number and allele length giving rise to species-specific band patterns. Expression study of pDS5 in bubaline samples by RNA slot-blot, Northern blot, and RT-PCR showed various levels of signal in all the somatic tissues and germline cells except heart. A GenBank database search revealed homology of pDS5 sequences in the 5' region from nt 1-1261 with collagen gene. An AluI typing analysis of DNA from bubaline semen samples showed consistent loss of two bands. The presence of corresponding bands in somatic tissues suggests a sequence modulation within the pDS5 array in meiocytes during spermatogenesis, which is restored in the somatic cells after fertilization. Modulation of the satellite-tagged transcribing sequence in the meiocytes may be a mechanism of its inactivation.