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Treatment of tuberculosis continues to be challenging due to the widespread latent form of the disease and the emergence of antibiotic-resistant strains of the pathogen,Mycobacterium tuberculosis. Bacterial ribosomes are a common and effective target for antibiotics. Several second line anti-tuberculosis drugs, e.g. kanamycin, amikacin, and capreomycin, target ribosomal RNA to inhibit protein synthesis. However,M. tuberculosiscan acquire resistance to these drugs, emphasizing the need to identify new drug targets. Previous cryo-EM structures of theM. tuberculosisandM. smegmatisribosomes identified two novel ribosomal proteins, bS22 and bL37, in the vicinity of two crucial drug-binding sites: the mRNA-decoding center on the small (30S), and the peptidyl-transferase center on the large (50S) ribosomal subunits, respectively. The functional significance of these two small proteins is unknown. In this study, we observe that anM. smegmatisstrain lacking thebs22gene shows enhanced susceptibility to kanamycin compared to the wild-type strain. Cryo-EM structures of the ribosomes lacking bS22 in the presence and absence of kanamycin suggest a direct role of bS22 in modulating the 16S rRNA kanamycin-binding site. Our structures suggest that amino-acid residue Lys-16 of bS22 interacts directly with the phosphate backbone of helix 44 of 16S rRNA to influence the micro-configuration of the kanamycin-binding pocket. Our analysis shows that similar interactions occur between eukaryotic homologues of bS22, and their corresponding rRNAs, pointing to a common mechanism of aminoglycoside resistance in higher organisms.

Missouri did not expand Medicaid, leaving about 500,000 Missourians without health insurance. To address community needs and provide additional social work training opportunities, a free integrated behavioral health clinic was established. This article discusses the need, describes the clinic, and presents 1-year evaluation results. Sixty-nine clients received services, and 30 students received intensive training during the first year. Almost half of the clients were diagnosed with depressive disorders, and more than half had comorbid medical conditions. Psychiatric symptoms were lower following treatment. Quality of life increased in physical and psychological domains. Collaborative clinics with social work and medical students are a viable option for experiential learning and providing quality care for uninsured or underinsured people with comorbid medical conditions.

Migration is a primary force of biological evolution that alters allele frequencies and introduces novel genetic variants into populations. Recent migration has been proposed as the cause of the emergence of many infectious diseases, including those carried by blacklegged ticks in North America. Populations of blacklegged ticks have established and flourished in areas of North America previously thought to be devoid of this species. The recent discovery of these populations of blacklegged ticks may have resulted from either in situ growth of long-established populations that were maintained at very low densities or by migration and colonization from established populations. These alternative evolutionary hypotheses were investigated using Bayesian phylogeographic approaches to infer the origin and migratory history of recently detected blacklegged tick populations in the Northeastern United States. The data and results indicate that newly detected tick populations are not the product of in situ population growth from a previously established population but from recent colonization resulting in a geographic range expansion. This expansion in the geographic range proceeded primarily through progressive and local migration events from southern populations to proximate northern locations although long-distance migration events were also detected.

Latent infections with periodic reactivation are a common outcome after acute infection with many viruses. The latency-associated transcript (LAT) gene is required for wild-type reactivation of herpes simplex virus (HSV). However, the underlying mechanisms remain unclear. In rabbit trigeminal ganglia, extensive apoptosis occurred withLAT−virus but not withLAT+viruses. In addition, a plasmid expressingLATblocked apoptosis in cultured cells. Thus,LATpromotes neuronal survival after HSV-1 infection by reducing apoptosis.

Bovine herpesvirus 1 (BHV-1) is a significant bovine pathogen, which causes respiratory disease, abortion, genital disease, or occasionally encephalitis (reviewed in reference 29). Like other members of the Alphaherpesvirinae subfamily, BHV-1 establishes latent infection in sensory ganglionic neurons (reviewed in reference 29). Viral DNA persists in these neurons for the lifetime of infected cattle but can periodically reactivate and spread. In contrast to the 70 to 80 viral genes expressed during productive infection, latency-related (LR) RNA is the only abundant viral transcript detected in latently infected neurons. A small fraction of LR RNA is polyadenylated and alternatively spliced in trigeminal ganglia (TG), suggesting that this RNA is translated into an LR protein (LRP) (8, 21, 27). LR gene products inhibit S-phase entry, and LRP is associated with cyclin-dependent kinase 2 (Cdk2)/cyclin complexes (27, 46). Cdk2/cyclin complexes regulate the transition from G1 to S to G2 (reviewed in reference 19) and are required for DNA replication (30). Cdk2 activity is stimulated after herpes simplex virus type 2 (HSV-2) infection (22) and is important for HSV-1 infection (47, 48). It is reasonable to hypothesize that members of the Alphaherpesvirinae subfamily utilize Cdk2 and perhaps other Cdks to stimulate viral DNA replication and transcription. Although the functional significance of the interactions between LRP and Cdk2/cyclin is not known, these interactions are likely to be important. Herpesviruses can induce programmed cell death (PCD), or apoptosis, when cultured cells are infected (reviewed in references 18 and 51). BHV-1 also induce PCD after infection of cultured cells (9, 14–17) or calves (53). Neuronal PCD occurs during neurodegenerative disorders, trauma, or imbalances of growth factors and cytokines (reviewed in references 10, 25, and 54). Expression of cell cycle regulatory proteins is frequently observed in neurons undergoing PCD, suggesting that altered Cdk activity initiates PCD (reviewed in reference 49). The HSV-1 US3 kinase plays a role in preventing PCD (1, 33), suggesting that regulation of PCD is crucial for pathogenesis. Inhibiting neuronal damage and/or PCD may also be important because the primary site of latency for BHV-1 is sensory neurons. This study demonstrated that LR gene products inhibit or delay PCD following transient transfection of CV-1 cells, low-passage human fibroblasts, or mouse neuroblastoma cells. Although there was a correlation between LR protein expression and cell survival, we cannot exclude the possibility that LR RNA by itself is important. We hypothesize that LR gene products promote neuronal survival by inhibiting PCD.

The use of chronic opioid therapy for persistent headache remains controversial because of limited supporting data and potential risks. In addition to possible individual risks for the patient, society risks associated with diversion and substance abuse are well documented. Few studies directly address risk stratification for opioid therapy where a diagnosis of headache is present, making it necessary to extrapolate from other pain research when developing recommendations for screening and patient management. Considering the historical framework of opioid prescribing, relevant studies assessing risk stratification of chronic opioid therapy are reviewed. Specific risk factors that may lead to a problematic course with chronic opioid therapy are outlined. Both clinical experience and the limited empirical research underscore the need for multiple assessment tools and ongoing patient monitoring in the evaluation of these risk factors.

Calves were inoculated with the bovine herpes virus 1 (BHV-1) vaccine strain (RLB 106), which is a temperature sensitive mutant. The route of inoculation was intranasal instillation or intramuscular (i.m.) injection (flank or neck). As a control, five calves were given placebo by i.m. injection of the neck. Regardless of the infection route, clinical symptoms did not occur. However, BHV-1 neutralizing antibodies were detected after inoculation demonstrating that sero-conversion occurred. At 60 days post-inoculation, dexamethasone was given by i.m. injection to attempt reactivation of RLB 106. Only those calves inoculated by the intranasal route shed virus leading to an increase in BHV-1 specific antibodies. As expected, viral DNA and the latency related-RNA were detected in trigeminal ganglia (TG) of calves inoculated by the intranasal route. In contrast, viral nucleic acid was not detected in TG of calves inoculated by the i.m. route or in calves inoculated with placebo. In cervical ganglia or sacral dorsal root ganglia, viral nucleic acid was not consistently detected. This study provides evidence that efficient latency and reactivation does not occur following i.m. inoculation. Since serum-neutralizing antibodies were detected in all inoculated calves, i.m. inoculation led to sero-conversion.

The population densities of many organisms have changed dramatically in recent history. Increases in the population density of medically relevant organisms are of particular importance to public health as they are often correlated with the emergence of infectious diseases in human populations. Our aim is to delineate increases in density of a common disease vector in North America, the blacklegged tick, and to identify the environmental factors correlated with these population dynamics. Empirical data that capture the growth of a population are often necessary to identify environmental factors associated with these dynamics. We analyzed temporally- and spatially-structured field collected data in a geographical information systems framework to describe the population growth of blacklegged ticks (Ixodes scapularis) and to identify environmental and climatic factors correlated with these dynamics. The density of the ticks increased throughout the study’s temporal and spatial ranges. Tick density increases were positively correlated with mild temperatures, low precipitation, low forest cover, and high urbanization. Importantly, models that accounted for these environmental factors accurately forecast future tick densities across the region. Tick density increased annually along the south-to-north gradient. These trends parallel the increases in human incidences of diseases commonly vectored by I. scapularis. For example, I. scapularis densities are correlated with human Lyme disease incidence, albeit in a non-linear manner that disappears at low tick densities, potentially indicating that a threshold tick density is needed to support epidemiologically-relevant levels of the Lyme disease bacterium. Our results demonstrate a connection between the biogeography of this species and public health.

A panel of monoclonal antibodies (MAbs) was generated against African horsesickness virus serotype 4 (AHSV/4). Three of the MAbs (SA6, OH3, and ME11) strongly neutralized the homologous virus and a heterologous type 4 isolate. The MAbs did not cross-neutralize AHS serotypes 1-3 or 5-9. The MAbs immunoprecipitated a viral protein of 108 kDa which co-migrated with VP2. Pretreatment with SA6 prevented mortality of 71% of day-old mice after intracranial injection of 100 LD50 of AHSV/4, while OH3 and ME11 significantly increased the average survival time of challenged animals. This study demonstrates that neutralizing epitope(s) for AHS are located on VP2 and that antibodies to these epitope(s) are protective in a neonatal mouse model.