Evolution of nasal and olfactory infection characteristics of SARS-CoV-2 variants

SARS-CoV-2 infection of the upper airway and the subsequent immune response are early, critical factors in COVID-19 pathogenesis. By studying infection of human biopsies in vitro and in a hamster model in vivo, we demonstrated a transition in nasal tropism from olfactory to respiratory epithelium as the virus evolved. Analyzing each variant revealed that SARS-CoV-2 WA1 or Delta infect a proportion of olfactory neurons in addition to the primary target sustentacular cells. The Delta variant possessed broader cellular invasion capacity into the submucosa, while Omicron displayed enhanced nasal respiratory infection and longer retention in the sinonasal epithelium. The olfactory neuronal infection by WA1 and the subsequent olfactory bulb transport via axon were more pronounced in younger hosts. In addition, the observed viral clearance delay and phagocytic dysfunction in aged olfactory mucosa were accompanied by a decline of phagocytosis-related genes. Further, robust basal stem cell activation contributed to neuroepithelial regeneration and restored ACE2 expression postinfection. Together, our study characterized the nasal tropism of SARS-CoV-2 strains, immune clearance, and regeneration after infection. The shifting characteristics of viral infection at the airway portal provide insight into the variability of COVID-19 clinical features, particularly long COVID, and may suggest differing strategies for early local intervention.

Evolution of nasal and olfactory infection characteristics of SARS-CoV-2 variants

SARS-CoV-2 infection of the upper airway and the subsequent immune response are early, critical factors in COVID-19 pathogenesis. By studying infection of human biopsies in vitro and in a hamster model in vivo, we demonstrated a transition in tropism from olfactory to respiratory epithelium as the virus evolved. Analyzing each variants revealed that SARS-CoV-2 WA1 or Delta infects a proportion of olfactory neurons in addition to the primary target sustentacular cells. The Delta variant possesses broader cellular invasion capacity into the submucosa, while Omicron displays longer retention in the sinonasal epithelium. The olfactory neuronal infection by WA1 and the subsequent olfactory bulb transport via axon is more pronounced in younger hosts. In addition, the observed viral clearance delay and phagocytic dysfunction in aged olfactory mucosa is accompanied by a decline of phagocytosis related genes. Furthermore, robust basal stem cell activation contributes to neuroepithelial regeneration and restores ACE2 expression post-infection. Together, our study characterized the nasal tropism of SARS-CoV-2 strains, immune clearance, and regeneration post infection. The shifting characteristics of viral infection at the airway portal provides insight into the variability of COVID-19 clinical features and may suggest differing strategies for early local intervention.

Hamsters as a Model of Severe Acute Respiratory Syndrome Coronavirus-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), rapidly spread across the world in late 2019, leading to a pandemic. While SARS-CoV-2 infections predominately affect the respiratory system, severe infections can lead to renal and cardiac injury and even death. Due to its highly transmissible nature and severe health implications, animal models of SARS-CoV-2 are critical to developing novel therapeutics and preventatives. Syrian hamsters (Mesocricetus auratus) are an ideal animal model of SARS-CoV-2 infections because they recapitulate many aspects of human infections. After inoculation with SARS-CoV-2, hamsters become moribund, lose weight, and show varying degrees of respiratory disease, lethargy, and ruffled fur. Histopathologically, their pulmonary lesions are consistent with human infections including interstitial to broncho-interstitial pneumonia, alveolar hemorrhage and edema, and granulocyte infiltration. Similar to humans, the duration of clinical signs and pulmonary pathology are short lived with rapid recovery by 14 d after infection. Immunocompromised hamsters develop more severe infections and mortality. Preclinical studies in hamsters have shown efficacy of therapeutics, including convalescent serum treatment, and preventatives, including vaccination, in limiting or preventing clinical disease. Although hamster studies have contributed greatly to our understanding of the pathogenesis and progression of disease after SARS-CoV-2 infection, additional studies are required to better characterize the effects of age, sex, and virus variants on clinical outcomes in hamsters. This review aims to describe key findings from studies of hamsters infected with SARS-CoV-2 and to highlight areas that need further investigation.

Sex Differences in Lung Imaging and SARS-CoV-2 Antibody Responses in a COVID-19 Golden Syrian Hamster Model

In the coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), more severe outcomes are reported in males than in females, including hospitalizations and deaths. Animal models can provide an opportunity to mechanistically interrogate causes of sex differences in the pathogenesis of SARS-CoV-2. Adult male and female golden Syrian hamsters (8 to 10 weeks of age) were inoculated intranasally with 105 50% tissue culture infective dose (TCID50) of SARS-CoV-2/USA-WA1/2020 and euthanized at several time points during the acute (i.e., virus actively replicating) and recovery (i.e., after the infectious virus has been cleared) phases of infection. There was no mortality, but infected male hamsters experienced greater morbidity, losing a greater percentage of body mass, developed more extensive pneumonia as noted on chest computed tomography, and recovered more slowly than females. Treatment of male hamsters with estradiol did not alter pulmonary damage. Virus titers in respiratory tissues, including nasal turbinates, trachea, and lungs, and pulmonary cytokine concentrations, including interferon-β (IFN-β) and tumor necrosis factor-α (TNF-α), were comparable between the sexes. However, during the recovery phase of infection, females mounted 2-fold greater IgM, IgG, and IgA responses against the receptor-binding domain of the spike protein (S-RBD) in both plasma and respiratory tissues. Female hamsters also had significantly greater IgG antibodies against whole-inactivated SARS-CoV-2 and mutant S-RBDs as well as virus-neutralizing antibodies in plasma. The development of an animal model to study COVID-19 sex differences will allow for a greater mechanistic understanding of the SARS-CoV-2-associated sex differences seen in the human population. IMPORTANCE Men experience more severe outcomes from coronavirus disease 2019 (COVID-19) than women. Golden Syrian hamsters were used to explore sex differences in the pathogenesis of a human isolate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). After inoculation, male hamsters experienced greater sickness, developed more severe lung pathology, and recovered more slowly than females. Sex differences in disease could not be reversed by estradiol treatment in males and were not explained by either virus replication kinetics or the concentrations of inflammatory cytokines in the lungs. During the recovery period, antiviral antibody responses in the respiratory tract and plasma, including to newly emerging SARS-CoV-2 variants, were greater in female than in male hamsters. Greater lung pathology during the acute phase combined with lower antiviral antibody responses during the recovery phase of infection in males than in females illustrate the utility of golden Syrian hamsters as a model to explore sex differences in the pathogenesis of SARS-CoV-2 and vaccine-induced immunity and protection.

Systemically delivered antibody-labeled magnetic iron oxide nanoparticles are less toxic than plain nanoparticles when activated by alternating magnetic fields

OBJECTIVE

Toxicity from off-target heating with magnetic hyperthermia (MHT) is generally assumed to be understood. MHT research focuses on development of more potent heating magnetic iron oxide nanoparticles (MIONs), yet our understanding of factors that define biodistribution following systemic delivery remains limited. Preclinical development relies on mouse models, thus understanding off-target heating with MHT in mice provides critical knowledge for clinical development.

METHODS

Eight-week old female nude mice received a single tail vein injection of bionized nanoferrite (BNF) MIONs or a counterpart labeled with a polyclonal human antibody (BNF-IgG) at 1 mg, 3 mg or 5 mg Fe/mouse on day 1. On day 3, mice were exposed to an alternating magnetic field (AMF) having amplitude of 32, 48 or 64 kA/m at ∼145 kHz for 20 min. Twenty-four hours later, blood, livers and spleens were harvested and analyzed.

RESULTS

Damage to livers was apparent by histology and serum liver enzymes following MHT with BNF or BNF-IgG at doses ≥3 mg Fe and AMF amplitudes ≥48 kA/m. Differences between effects with BNF vs. BNF-IgG at a dose of 3 mg Fe were noted in all measures, with less damage and increased survival occurring in mice injected with BNF-IgG. Necropsies revealed severe damage to duodenum and upper small intestines, likely the immediate cause of death at the highest MHT doses.

CONCLUSION

Results demonstrate that the MION coating affects biodistribution, which in turn determines off-target effects. Developments to improve heating capabilities of MIONs may be clinically irrelevant without better control of biodistribution.

Sex differences in lung imaging and SARS-CoV-2 antibody responses in a COVID-19 golden Syrian hamster model

In the ongoing coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), more severe outcomes are reported in males compared with females, including hospitalizations and deaths. Animal models can provide an opportunity to mechanistically interrogate causes of sex differences in the pathogenesis of SARS-CoV-2. Adult male and female golden Syrian hamsters (8-10 weeks of age) were inoculated intranasally with 10 ⁵ TCID ₅₀ of SARS-CoV-2/USA-WA1/2020 and euthanized at several time points during the acute (i.e., virus actively replicating) and recovery (i.e., after the infectious virus has been cleared) phases of infection. There was no mortality, but infected male hamsters experienced greater morbidity, losing a greater percentage of body mass, developing more extensive pneumonia as noted on chest computed tomography, and recovering more slowly than females. Treatment of male hamsters with estradiol did not alter pulmonary damage. Virus titers in respiratory tissues, including nasal turbinates, trachea, and lungs, and pulmonary cytokine concentrations, including IFNb and TNFa, were comparable between the sexes. However, during the recovery phase of infection, females mounted two-fold greater IgM, IgG, and IgA responses against the receptor-binding domain of the spike protein (S-RBD) in both plasma and respiratory tissues. Female hamsters also had significantly greater IgG antibodies against whole inactivated SARS-CoV-2 and mutant S-RBDs, as well as virus neutralizing antibodies in plasma. The development of an animal model to study COVID-19 sex differences will allow for a greater mechanistic understanding of the SARS-CoV-2 associated sex differences seen in the human population.

Noninvasive evaluation of intragraft immune responses in upper extremity transplantation

In vascularized composite allotransplantation (VCA), invasive tissue biopsies remain the gold standard in diagnosing rejection carrying significant morbidity. We aimed to show feasibility of tape-stripping for noninvasive immune monitoring in VCA. Tape-stripping was performed on allografts and native skin of upper extremity transplant recipients. Healthy nontransplanted individuals served as controls. The technique was also used in swine on naïve skin in nontransplanted animals, native skin of treated, transplanted swine, nonrejecting VCAs, and rejecting VCAs. Extracted protein was analyzed for differences in cytokine expression using Luminex technology. Significantly decreased levels of INFγ and IL-1Ra were seen between human allograft samples and native skin. In swine, rejecting grafts had increased IL-1Ra compared to naïve and native skin, decreased levels of GM-CSF compared to native skin, and decreased IL-10 compared to nonrejecting grafts. Unsupervised hierarchical clustering revealed rejecting grafts separated from the nonrejecting (P = 0.021). Variable importance in projection scores identified GM-CSF, IL-1Ra, and IL-2 as the most important profiles for group discrimination. Differences in cytokine expression are detectable in human VCA patient native skin and VCA graft skin using a noninvasive tape-stripping method. Swine studies suggest that differences in cytokines between rejecting and nonrejecting grafts are discernable.

Latissimus Dorsi Myocutaneous Flap Procedure in a Swine Model

BACKGROUND

As surgical research expands in both breadth and scope, translational models become increasingly important. The accessibility, reproducibility, and clinical applicability of translational models is of vital importance to ensure adequate and accurate research. Though different flap models have been described, the literature lacks an in-depth, technical description of an easy large-animal preclinical model. We here describe the procedure for elevation of a latissimus dorsi flap in a swine. This flap contains muscle and skin that can be isolated on a vascular pedicle, transferred as a free flap, perfused, or innervated/denervated as dictated by the needs of the experiment.

METHODS

Five different latissimus dorsi flaps were elevated in miniature swine. Careful attention was paid to anatomical landmarks and optimal placement of incision, dissection, and retraction. Temporary ischemia with vascular clamping was performed along with serial digital and infrared imaging both intra- and postoperatively. In three of the flaps with induced ischemia, the animal was observed for a 30-day follow up with daily photodocumentation and intermittent biopsy.

RESULTS

A reproducible latissimus flap model was designed with optimized conditions. In the animals in which flaps were followed postoperatively, complete healing was seen within 30 days without evidence of procedure-related ischemia or loss of motor function.

CONCLUSION

We have identified and described a pre-clinical large animal flap model that can be easily reproduced for translational studies of multiple scientific areas including flap-based repair, ischemia, ischemia reperfusion, and operative technique. This provides an important model for ready replication in preclinical studies of many varieties.

0885 Reduction in Emergency Department and Inpatient Hospitalization Visits and Length of Stay in a Cohort of Pediatric Patients Initiated on Positive Airway Pressure for Obstructive Sleep Apnea Syndrome

Introduction

Positive Airway Pressure (PAP) is an efficacious treatment of pediatric obstructive sleep apnea syndrome (OSAS). However, it is unknown whether PAP initiation is associated with reduced healthcare utilization, an important metric of care management. We hypothesized that healthcare utilization would be reduced after initiation of PAP in a cohort of pediatric patients prescribed PAP for OSAS.

Methods

Data were extracted from electronic medical records of 475 patients (Mean±SD age at PAP initiation=7.7±5.7 years; 58.7% male; 40.6% White; 38.3% Black; 18.1% multiracial/other; 12.1% Hispanic/Latinx) prescribed PAP for OSAS and followed in our Sleep Center quality improvement program. We extracted the total number of emergency department (ED) visits and hospitalizations and computed the related average length of stay (LOS) in hours for these visits in the 18 months prior to and 18 months following PAP initiation.

Results

Paired samples t-tests showed that number of ED visits and hospitalizations, and the related visit LOS, were significantly reduced following PAP initiation. The average number of visits reduced from 2.20 pre-PAP to 1.77 post-PAP initiation [t(474) = 3.48, p<.001, effect size = 0.16], while average LOS reduced from 185.14 hours pre-PAP to 42.94 hours post-PAP initiation [t(474) = 4.81, p<.001, effect size = 0.29]. Findings for the significant reduction in LOS held after adjusting for the number of pre and post-PAP ED visits and hospitalizations, average pre-PAP LOS, and patient demographics (age at the time of initiation; sex; race/ethnicity) using multiple linear regression.

Conclusion

PAP initiation was associated with fewer and shorter ED visits and hospitalizations in a large sample of pediatric patients. We speculate that PAP initiation could help reduce morbidity associated with pediatric OSAS, as well as improve healthcare utilization, capacity management and care in this population.

Support

K23HD094905 and Sleep Research Foundation (AAW)

Efficacy of single-agent immunosuppressive regimens in a murine model of vascularized composite allotransplantation

We herein investigate the safety and efficacy of single-agent anti-rejection regimens in a mouse vascularized composite allotransplantation (VCA) model. Orthotopic hind-limb transplantations (Balb/c → C57BL/6) were performed using 6- to 8-week-old mice. A thirty-day regimen of either rapamycin, tacrolimus (both 1, 3, 5 mg/kg/day) or cyclosporine (25, 35, 50 mg/kg/day) was used. Primary endpoints were animal and graft survival, and secondary chimerism and regulatory T-cell levels. For rapamycin and tacrolimus given at 1, 3, and 5 mg/kg/day, median graft survival time (MST) was 23 days (18-28 days), 30 days (23-30 days), and 30 d (30-30 days) and 14 days (13-18 days), 30 days (16-30 days), and 30 days (30-30 days), respectively. For cyclosporine dosed at 25 and 35 mg/kg/day, MST was 15 days (12-18 days) and 21 days (14-27 days). Toxicity from CsA 50 mg/kg led to 100% mortality. Mixed chimerism levels were higher in rapamycin-treated animals than in tacrolimus-treated recipients (P = 0.029). Tacrolimus was superior in preventing leukocyte recruitment to the allograft. In murine VCA, no standardized immunosuppressive regimen exists, limiting comparability of outcomes and survival. Our data demonstrate that rapamycin and tacrolimus maintenance treatment at 5 mg/kg/day both yielded allograft survival (<grade 3 rejection) in all animals. Rapamycin displayed less toxicity and maintained mixed chimerism but was not as potent in controlling leukocyte recruitment compared with tacrolimus.

Brain macrophages harbor latent, infectious simian immunodeficiency virus

: The current review examines the role of brain macrophages, that is perivascular macrophages and microglia, as a potential viral reservoir in antiretroviral therapy (ART) treated, simian immunodeficiency virus (SIV)-infected macaques. The role, if any, of latent viral reservoirs of HIV and SIV in the central nervous system during ART suppression is an unresolved issue. HIV and SIV infect both CD4 lymphocytes and myeloid cells in blood and tissues during acute and chronic infection. HIV spread to the brain occurs during acute infection by the infiltration of activated CD4 lymphocytes and monocytes from blood and is established in both embryonically derived resident microglia and monocyte-derived perivascular macrophages. ART controls viral replication in peripheral blood and cerebrospinal fluid in HIV-infected individuals but does not directly eliminate infected cells in blood, tissues or brain. Latently infected resting CD4 lymphocytes in blood and lymphoid tissues are a well recognized viral reservoir that can rebound once ART is withdrawn. In contrast, central nervous system resident microglia and perivascular macrophages in brain have not been examined as potential reservoirs for HIV during suppressive ART. Macrophages in tissues are long-lived cells that are HIV and SIV infected in tissues such as gut, lung, spleen, lymph node and brain and contribute to ongoing inflammation in tissues. However, their potential role in viral persistence and latency or their potential to rebound in the absence ART has not been examined. It has been shown that measurement of HIV latency by HIV DNA PCR in CD4 lymphocytes overestimates the size of the latent reservoirs of HIV that contribute to rebound that is cells containing the genomes of replicative viruses. Thus, the quantitative viral outgrowth assay has been used as a reliable measure of the number of latent cells that harbor infectious viral DNA and, may constitute a functional latent reservoir. Using quantitative viral outgrowth assays specifically designed to quantitate latently infected CD4 lymphocytes and myeloid cells in an SIV macaque model, we demonstrated that macrophages in brain harbor SIV genomes that reactivate and produce infectious virus in this assay, demonstrating that these cells have the potential to be a reservoir.

Comorbid diabetes results in immune dysregulation and enhanced disease severity following MERS-CoV infection

Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in 2012 in Saudi Arabia and has caused over 2400 cases and more than 800 deaths. Epidemiological studies identified diabetes as the primary comorbidity associated with severe or lethal MERS-CoV infection. Understanding how diabetes affects MERS is important because of the global burden of diabetes and pandemic potential of MERS-CoV. We used a model in which mice were made susceptible to MERS-CoV by expressing human DPP4, and type 2 diabetes was induced by administering a high-fat diet. Upon infection with MERS-CoV, diabetic mice had a prolonged phase of severe disease and delayed recovery that was independent of virus titers. Histological analysis revealed that diabetic mice had delayed inflammation, which was then prolonged through 21 days after infection. Diabetic mice had fewer inflammatory monocyte/macrophages and CD4+ T cells, which correlated with lower levels of Ccl2 and Cxcl10 expression. Diabetic mice also had lower levels of Tnfa, Il6, Il12b, and Arg1 expression and higher levels of Il17a expression. These data suggest that the increased disease severity observed in individuals with MERS and comorbid type 2 diabetes is likely due to a dysregulated immune response, which results in more severe and prolonged lung pathology.

Myeloid and CD4 T Cells Comprise the Latent Reservoir in Antiretroviral Therapy-Suppressed SIVmac251-Infected Macaques

Human immunodeficiency virus (HIV) eradication or long-term suppression in the absence of antiretroviral therapy (ART) requires an understanding of all viral reservoirs that could contribute to viral rebound after ART interruption. CD4 T cells (CD4s) are recognized as the predominant reservoir in HIV type 1 (HIV-1)-infected individuals. However, macrophages are also infected by HIV-1 and simian immunodeficiency virus (SIV) during acute infection and may persist throughout ART, contributing to the size of the latent reservoir. We sought to determine whether tissue macrophages contribute to the SIVmac251 reservoir in suppressed macaques. Using cell-specific quantitative viral outgrowth assays (CD4-QVOA and MΦ-QVOA), we measured functional latent reservoirs in CD4s and macrophages in ART-suppressed SIVmac251-infected macaques. Spleen, lung, and brain in all suppressed animals contained latently infected macrophages, undetectable or low-level SIV RNA, and detectable SIV DNA. Silent viral genomes with potential for reactivation and viral spread were also identified in blood monocytes, although these cells might not be considered reservoirs due to their short life span. Additionally, virus produced in the MΦ-QVOA was capable of infecting healthy activated CD4s. Our results strongly suggest that functional latent reservoirs in CD4s and macrophages can contribute to viral rebound and reestablishment of productive infection after ART interruption. These findings should be considered in the design and implementation of future HIV cure strategies.IMPORTANCE This study provides further evidence that the latent reservoir is comprised of both CD4+ T cells and myeloid cells. The data presented here suggest that CD4+ T cells and macrophages found throughout tissues in the body can contain replication-competent SIV and contribute to rebound of the virus after treatment interruption. Additionally, we have shown that monocytes in blood contain latent virus and, though not considered a reservoir themselves due to their short life span, could contribute to the size of the latent reservoir upon entering the tissue and differentiating into long-lived macrophages. These new insights into the size and location of the SIV reservoir using a model that is heavily studied in the HIV field could have great implications for HIV-infected individuals and should be taken into consideration with the development of future HIV cure strategies.

A Skin Rejection Grading System for Vascularized Composite Allotransplantation in a Preclinical Large Animal Model

BACKGROUND

The Banff Criteria have been accepted as a system for grading histological rejection in graft skin in human vascularized composite allotransplantation (VCA). Preclinical swine hindlimb transplantation models have an important role in translational studies in VCA. However, unified grading criteria for rejection in swine skin have not yet been established.

METHODS

Two hundred fourteen swine skin biopsy specimens were reviewed, including 88 native skin biopsies and 126 specimens from the skin component of heterotopic swine hindlimb transplants. Thorough review was performed in a blinded fashion by an expert veterinary pathologist with attention paid to the applicability of the Banff criteria as well as specific histologic characteristics and trends. Clinical and histopathologic rejection scores were then directly compared.

RESULTS

Two hundred fourteen specimens reviewed showed significant similarities between swine and human skin, as previously published. Notable swine-specific characteristics, including paucicellular infiltration with rare epidermal cell infiltration or necrosis, were accounted for in a proposed grading system that parallels the Banff Criteria.

CONCLUSIONS

This comprehensive grading system, based on the Banff Classification for skin rejection in VCA, provides a standardized system for more accurate comparison of rejection in preclinical swine VCA models.

Non-toxigenic Bacteroides fragilis (NTBF) administration reduces bacteria-driven chronic colitis and tumor development independent of polysaccharide A

Polysaccharide A (PSA), an immunogenic capsular component of non-toxigenic Bacteroides fragilis (NTBF) strain NCTC 9343, is reported to promote mucosal immune development and suppress colitis. Contrastingly, enterotoxigenic Bacteroides fragilis (ETBF) is highly associated with inflammatory bowel disease (IBD) and colorectal cancer (CRC), rapidly inducing IL-17-dependent murine colitis and tumorigenesis. In specific-pathogen-free (SPF) C57BL/6 wild-type (WT) and multiple intestinal neoplasia (MinApc716+/-) mice, we show that sequential treatment of the NTBF strain, 9343, followed by the ETBF strain, 86-5443-2-2 (86), diminished colitis and tumorigenesis. Mice treated simultaneously with 9343 and 86 exhibited both severe colitis and tumorigenesis. Abrogated disease severity in sequentially treated mice was attributed to 9343 strain dominance and decreased IL-17A, but 86 colonization prior to or simultaneous with 9343 mitigated the anti-inflammatory effect of 9343. Remarkably, 9343-mediated protection was independent of PSA, as sequentially treated mice receiving ΔPSA 9343 exhibited similar protection. Further, SPF WT and Min mice colonized with PSA-competent or PSA-deficient 9343 exhibited similar IL-10, IL-17, and IFN-γ responses. Treatment of 86-colonized mice with 9343 failed to disrupt 86 pathogenesis. Our findings demonstrate that 9343 colonization, independent of PSA, offers prophylaxis against colitis-inducing 86 but may not be a valid therapy once colitis is established.

Does B Cell Follicle Exclusion of CD8+ T Cells Make Lymph Nodes Sanctuaries of HIV Replication?

As we learn more about the HIV latent reservoir, we continue to discover that the viral reservoir is more complicated than just a pool of infected resting memory CD4+ T cells in peripheral blood. Evidence increasingly points to both certain tissues and certain types of cells as potential viral reservoirs. T follicular helper cells (T_FH) are prime targets of HIV infection-this creates a sanctuary for infected cells because CD8+ T cells generally do not enter lymph node follicles unless they express CXCR5, and are not as effective at killing infected CD4+ T cells as peripheral CD8+ T cells. In this review, we summarize the current state of research on T_FH cell infection in peripheral lymphoid tissues and focus on the question of whether CD8+ T cell exclusion from B cell follicles is responsible, at least in part, for establishing secondary lymphoid tissue B cell follicles as an anatomic site of HIV transcription and replication.

Cross-reactive microbial peptides can modulate HIV-specific CD8+ T cell responses

Heterologous immunity is an important aspect of the adaptive immune response. We hypothesized that this process could modulate the HIV-1-specific CD8+ T cell response, which has been shown to play an important role in HIV-1 immunity and control. We found that stimulation of peripheral blood mononuclear cells (PBMCs) from HIV-1-positive subjects with microbial peptides that were cross-reactive with immunodominant HIV-1 epitopes resulted in dramatic expansion of HIV-1-specific CD8+ T cells. Interestingly, the TCR repertoire of HIV-1-specific CD8+ T cells generated by ex vivo stimulation of PBMCs using HIV-1 peptide was different from that of cells stimulated with cross-reactive microbial peptides in some HIV-1-positive subjects. Despite these differences, CD8+ T cells stimulated with either HIV-1 or cross-reactive peptides effectively suppressed HIV-1 replication in autologous CD4+ T cells. These data suggest that exposure to cross-reactive microbial antigens can modulate HIV-1-specific immunity.

SIV Latency in Macrophages in the CNS

Lentiviruses infect myeloid cells, leading to acute infection followed by persistent/latent infections not cleared by the host immune system. HIV and SIV are lentiviruses that infect CD4+ lymphocytes in addition to myeloid cells in blood and tissues. HIV infection of myeloid cells in brain, lung, and heart causes tissue-specific diseases that are mostly observed during severe immunosuppression, when the number of circulating CD4+ T cells declines to exceeding low levels. Antiretroviral therapy (ART) controls viral replication but does not successfully eliminate latent virus, which leads to viral rebound once ART is interrupted. HIV latency in CD4+ lymphocytes is the main focus of research and concern when HIV eradication efforts are considered. However, myeloid cells in tissues are long-lived and have not been routinely examined as a potential reservoir. Based on a quantitative viral outgrowth assay (QVOA) designed to evaluate latently infected CD4+ lymphocytes, a similar protocol was developed for the assessment of latently infected myeloid cells in blood and tissues. Using an SIV ART model, it was demonstrated that myeloid cells in blood and brain harbor latent SIV that can be reactivated and produce infectious virus in vitro, demonstrating that myeloid cells have the potential to be an additional latent reservoir of HIV that should be considered during HIV eradication strategies.

Lymphocyte-Dominant Encephalitis and Meningitis in Simian Immunodeficiency Virus-Infected Macaques Receiving Antiretroviral Therapy

A retrospective neuropathologic review of 30 SIV-infected pigtailed macaques receiving combination antiretroviral therapy (cART) was conducted. Seventeen animals with lymphocyte-dominant inflammation in the brain and/or meninges that clearly was morphologically distinct from prototypic SIV encephalitis and human immunodeficiency virus encephalitis were identified. Central nervous system (CNS) infiltrates in cART-treated macaques primarily comprised CD20⁺ B cells and CD3⁺ T cells with fewer CD68⁺ macrophages. Inflammation was associated with low levels of SIV RNA in the brain as shown by in situ hybridization, and generally was observed in animals with episodes of cerebrospinal fluid (CSF) viral rebound or sustained plasma and CSF viremia during treatment. Although the lymphocytic CNS inflammation in these macaques shared morphologic characteristics with uncommon immune-mediated neurologic disorders reported in treated HIV patients, including CNS immune reconstitution inflammatory syndrome and neurosymptomatic CSF escape, the high prevalence of CNS lesions in macaques suggests that persistent adaptive immune responses in the CNS also may develop in neuroasymptomatic or mildly impaired HIV patients yet remain unrecognized given the lack of access to CNS tissue for histopathologic evaluation. Continued investigation into the mechanisms and outcomes of CNS inflammation in cART-treated, SIV-infected macaques will advance our understanding of the consequences of residual CNS HIV replication in patients on cART, including the possible contribution of adaptive immune responses to HIV-associated neurocognitive disorders.

An SIV/macaque model targeted to study HIV-associated neurocognitive disorders

Simian immunodeficiency virus (SIV) infection of pigtailed macaques is a highly representative and well-characterized animal model for HIV neuropathogenesis studies that provides an excellent opportunity to study and develop prognostic markers of HIV-associated neurocognitive disorders (HAND) for HIV-infected individuals. SIV studies can be performed in a controlled setting that enhances reproducibility and offers high-translational value. Similar to observations in HIV-infected patients receiving antiretroviral therapy (ART), ongoing neurodegeneration and inflammation are present in SIV-infected pigtailed macaques treated with suppressive ART. By developing quantitative viral outgrowth assays that measure both CD4+ T cells and macrophages harboring replication competent SIV as well as a highly sensitive mouse-based viral outgrowth assay, we have positioned the SIV/pigtailed macaque model to advance our understanding of latent cellular reservoirs, including potential CNS reservoirs, to promote HIV cure. In addition to contributing to our understanding of the pathogenesis of HAND, the SIV/pigtailed macaque model also provides an excellent opportunity to test innovative approaches to eliminate the latent HIV reservoir in the brain.

Constructively Challenging Diverse Inner-City Youth's Beliefs About Educational and Career Barriers and Supports

This study examines school and work barrier beliefs about the limitations of education for future career rewards and perceived supports for attaining the educational and career aspirations of low-income, inner-city, African American, Hispanic/Latino(a), and Caribbean immigrant youth. The authors find that higher levels of school andwork barrier beliefs are associated with lower aspirations, particularly for minority youth who are less recent immigrants. The authors described workshops designed to constructively challenge counterproductive school and work barrier beliefs by expanding participants' learning about accessible sources of support for attaining their school, work, and life goals. Results indicate that participants endorse two types of support sources: contextual supports (relational and community resources accessible in their environments) and personal resources (psychological assets within the individual). The authors propose that personal resources be conceptualized from social learning theory as facilitative task approach skills (e.g., productive work habits, learning-oriented performance expectations, helpful cognitive processes, beneficial problem orientations, self-regulated emotional responses, and other personal assets).

Serum Cobalamin (Vitamin B12) Concentrations in Rhesus Macaques (Macaca mulatta) and Pigtailed Macaques (Macaca nemestrina) with Chronic Idiopathic Diarrhea

Chronic diarrhea poses a significant threat to the health of NHP research colonies, and its primary etiology remains unclear. In macaques, the clinical presentation of intractable diarrhea and weight loss that are accompanied by inflammatory infiltrates within the gastrointestinal tract closely resembles inflammatory bowel disease of humans, dogs, and cats, in which low serum and tissue cobalamin (vitamin B12) levels are due to intestinal malabsorption. We therefore hypothesized that macaques with chronic idiopathic diarrhea (CID) have lower serum cobalamin concentrations than do healthy macaques. Here we measured serum cobalamin concentrations in both rhesus and pigtailed macaques with CID and compared them with those of healthy controls. Serum cobalamin levels were 2.5-fold lower in pigtailed macaques with CID than control animals but did not differ between rhesus macaques with CID and their controls. This finding supports the use of serum cobalamin concentration as an adjunct diagnostic tool in pigtailed macaques that present with clinical symptoms of chronic gastrointestinal disease. This use of serum vitamin B12 levels has implications for the future use of parenteral cobalamin supplementation to improve clinical outcomes in this species.

Potential role of cervicovaginal extracellular particles in diagnosis of endometriosis

Background

Macaques are an excellent model for many human diseases, including reproductive diseases such as endometriosis. A long-recognized need for early biomarkers of endometriosis has not yet resulted in consensus. While biomarker studies have examined many bodily fluids and targets, cervicovaginal secretions have been relatively under-investigated. Extracellular vesicles (EVs, including exosomes and microvesicles) are found in every biofluid examined, carry cargo including proteins and RNA, and may participate in intercellular signaling. Little is known about EVs in the cervicovaginal compartment, including the effects of reproductive tract disease on quantity and quality of EVs.

Case presentation

In September 2014, a 9-year-old rhesus macaque was diagnosed with endometriosis at The Johns Hopkins University School of Medicine. Ultrasound-guided fine needle aspiration of a cyst and subsequent laparotomy confirmed diagnosis. The animal was sent to necropsy following euthanasia for humane reasons. Perimortem vaginal swabs and cervicovaginal lavages were obtained. Using a combination of methods, including ultracentrifugation and NanoSight visualization technology, approximate numbers of EVs from each sample were calculated and compared to populations of EVs from other, reproductively normal macaques. Fewer EVs were recovered from the endometriosis samples as compared with those from reproductively healthy individuals.

Conclusion

To our knowledge, this is the first examination of EVs in primate cervicovaginal secretions, including those of a macaque with endometriosis. This case study suggests that additional research is justified to determine whether quantification of EVs—or their molecular cargo—in cervicovaginal lavage and vaginal swabs may provide a novel, relatively non-invasive diagnostic for primate endometrial disease or other reproductive tract diseases.

Paving the path to HIV neurotherapy: Predicting SIV CNS disease

HIV-induced damage to the CNS remains a major challenge for over 30 million people in the world despite the successes of combined antiretroviral therapy in limiting viral replication. Predicting development and progression of HIV-associated CNS disease is crucial because prevention and early intervention could be more effective than attempts to promote repair. The SIV/macaque model is the premier platform to study HIV neuropathogenesis, including discovery of predictive factors such as neuroprotective host genes and both blood and CSF biomarkers that precede and predict development of SIV CNS disease. This report details the role of macaque MHC class I genes, longitudinal alterations in biomarkers in the circulation, and expression of inflammatory and neuronal damage markers in CSF using samples from SIV-inoculated pigtailed macaques collected during acute, asymptomatic, and terminal stages of infection.

Loss of corneal sensory nerve fibers in SIV-infected macaques: an alternate approach to investigate HIV-induced PNS damage

Peripheral neuropathy is the most frequent neurological complication of HIV infection, affecting more than one-third of infected patients, including patients treated with antiretroviral therapy. Although emerging noninvasive techniques for corneal nerve assessments are increasingly being used to diagnose and monitor peripheral neuropathies, corneal nerve alterations have not been characterized in HIV. Here, to determine whether SIV infection leads to corneal nerve fiber loss, we immunostained corneas for the nerve fiber marker βIII tubulin. We developed and applied both manual and automated methods to measure nerves in the corneal subbasal plexus. These counting methods independently indicated significantly lower subbasal corneal nerve fiber density among SIV-infected animals that rapidly progressed to AIDS compared with slow progressors. Concomitant with decreased corneal nerve fiber density, rapid progressors had increased levels of SIV RNA and CD68-positive macrophages and expression of glial fibrillary acidic protein by glial satellite cells in the trigeminal ganglia, the location of the neuronal cell bodies of corneal sensory nerve fibers. In addition, corneal nerve fiber density was directly correlated with epidermal nerve fiber length. These findings indicate that corneal nerve assessment has great potential to diagnose and monitor HIV-induced peripheral neuropathy and to set the stage for introducing noninvasive techniques to measure corneal nerve fiber density in HIV clinical settings.

CCR5 inhibition prevents cardiac dysfunction in the SIV/macaque model of HIV

Background

Diastolic dysfunction is a highly prevalent cardiac abnormality in asymptomatic as well as ART‐treated human immunodeficiency virus (HIV) patients. Although the mechanisms underlying depressed cardiac function remain obscure, diastolic dysfunction in SIV‐infected rhesus macaques is highly correlated with myocardial viral load. As cardiomyocytes are not productively infected, damage may be an indirect process attributable to a combination of pro‐inflammatory mediators and viral proteins.

Methods and Results

Given the diverse roles of CCR5 in mediating recruitment of leukocytes to inflammatory sites and serving as a receptor for HIV entry into cells, we investigated the role of CCR5 in the SIV/macaque model of diastolic dysfunction. We found that in SIV‐infected macaques, CCR5 inhibition dramatically impacted myocardial viral load measured by qRT‐PCR and prevented diastolic dysfunction measured by echocardiography. Complementary in vitro experiments using fluorescence microscopy showed that CCR5 ligands impaired contractile function of isolated cardiomyocytes, thus identifying CCR5 signaling as a novel mediator of impaired cardiac mechanical function.

Conclusions

Together, these findings incriminate SIV/HIV gp120‐CCR5 as well as chemokine‐CCR5 interactions in HIV‐associated cardiac dysfunction. These findings also have important implications for the treatment of HIV‐infected individuals: in addition to antiviral properties and reduced chemokine‐mediated recruitment and activation of inflammatory cells, CCR5 inhibition may provide a cardioprotective benefit by preventing cardiomyocyte CCR5 signaling.

Neuroprotective maraviroc monotherapy in simian immunodeficiency virus-infected macaques: reduced replicating and latent SIV in the brain

OBJECTIVE

HIV-associated neurocognitive deficits remain a challenge despite suppressive combined antiretroviral therapy. Given the association between HIV-induced central nervous system (CNS) disease and replication of HIV in immune-activated macrophages, CCR5 antagonists may attenuate CNS disease by modulating inflammatory signaling and by limiting viral replication.

DESIGN

To establish whether initiating CCR5 inhibition during early infection altered CNS disease progression, outcomes were compared between simian immunodeficiency virus (SIV)-infected macaques treated with maraviroc (MVC) versus untreated SIV-infected macaques.

METHODS

Six SIV-infected rhesus macaques were treated with MVC monotherapy for 5 months beginning 24 days postinoculation; 22 SIV-infected animals served as untreated controls. SIV RNA levels in plasma, cerobrospinal fluid, and brain, and CNS expression of TNFα and CCL2 were measured by qRT-PCR. Immunostaining for CD68 and amyloid precursor protein in the brain was measured by image analysis. Plasma sCD163 was measured by ELISA.

RESULTS

SIV RNA and proviral DNA levels in brain were markedly lower with MVC treatment, demonstrating CCR5 inhibition reduces CNS replication of SIV and may reduce the CNS latent viral reservoir. MVC treatment also lowered monocyte and macrophage activation, represented by CNS CD68 immunostaining and plasma sCD163 levels, and reduced both TNFα and CCL2 RNA expression in brain. Treatment also reduced axonal amyloid precursor protein immunostaining to levels present in uninfected animals, consistent with neuroprotection.

CONCLUSION

CCR5 inhibitors may prevent neurologic disorders in HIV-infected individuals by reducing inflammation and by limiting viral replication in the brain. Furthermore, CCR5 inhibitors may reduce the latent viral reservoir in the CNS. Adding CCR5 inhibitors to combined antiretroviral regimens may offer multiple neuroprotective benefits.

Eradication of Helicobacter spp. by using medicated diet in mice deficient in functional natural killer cells and complement factor D

A commercial 4-drug diet has shown promise in eradicating Helicobacter spp. from rodents; however, its effectiveness in immunocompromised mice is unknown. This study evaluated the efficacy of this treatment in eradicating Helicobacter spp. from mice deficient in functional natural killer cells (Cd1(-/-)) or complement factor D (Df(-/-)). Cd1(-/-) mice naturally infected with H. hepaticus with or without H. rodentium were fed either control or medicated diet for 8 wk followed by 4 wk on control diet. Fecal samples were PCR-evaluated for Helicobacter spp. before mice began treatment and then every 2 wk thereafter for 12 wk. The same experimental design was repeated for eighteen 9- to 21-wk-old Df(-/-) mice naturally infected with H. bilis with or without H. rodentium. All Df(-/-) mice and 8- to 21-wk-old Cd1(-/-) mice ceased shedding Helicobacter spp. after 2 wk of treatment and remained negative throughout the study. In contrast, the Cd1(-/-) mice that were 24 wk or older shed Helicobacter spp. for the first 8 wk but tested negative at 10 and 12 wk. All treated animals had enlarged ceca and gained less weight than control untreated mice, and 6 of 7 treated Cd1(-/-) male mice developed mild portal fibrosis. These findings show that within 2 wk of treatment, the 4-drug diet eradicated H. hepaticus and H. rodentium from young Cd1(-/-) mice and H. bilis and H. rodentium from Df(-/-) mice, but eradication of established infections in Cd1(-/-) mice required 8 wk of treatment.

Effect of low pH on single skeletal muscle myosin mechanics and kinetics

Acidosis (low pH) is the oldest putative agent of muscular fatigue, but the molecular mechanism underlying its depressive effect on muscular performance remains unresolved. Therefore, the effect of low pH on the molecular mechanics and kinetics of chicken skeletal muscle myosin was studied using in vitro motility (IVM) and single molecule laser trap assays. Decreasing pH from 7.4 to 6.4 at saturating ATP slowed actin filament velocity (V(actin)) in the IVM by 36%. Single molecule experiments, at 1 microM ATP, decreased the average unitary step size of myosin (d) from 10 +/- 2 nm (pH 7.4) to 2 +/- 1 nm (pH 6.4). Individual binding events at low pH were consistent with the presence of a population of both productive (average d = 10 nm) and nonproductive (average d = 0 nm) actomyosin interactions. Raising the ATP concentration from 1 microM to 1 mM at pH 6.4 restored d (9 +/- 3 nm), suggesting that the lifetime of the nonproductive interactions is solely dependent on the [ATP]. V(actin), however, was not restored by raising the [ATP] (1-10 mM) in the IVM assay, suggesting that low pH also prolongs actin strong binding (t(on)). Measurement of t(on) as a function of the [ATP] in the single molecule assay suggested that acidosis prolongs t(on) by slowing the rate of ADP release. Thus, in a detachment limited model of motility (i.e., V(actin) approximately d/t(on)), a slowed rate of ADP release and the presence of nonproductive actomyosin interactions could account for the acidosis-induced decrease in V(actin), suggesting a molecular explanation for this component of muscular fatigue.

Hypertrophic and dilated cardiomyopathy mutations differentially affect the molecular force generation of mouse α-cardiac myosin in the laser trap assay

Point mutations in cardiac myosin, the heart's molecular motor, produce distinct clinical phenotypes: hypertrophic (HCM) and dilated (DCM) cardiomyopathy. Do mutations alter myosin's molecular mechanics in a manner that is predictive of the clinical outcome? We have directly characterized the maximal force-generating capacity (Fmax) of two HCM (R403Q, R453C) and two DCM (S532P, F764L) mutant myosins isolated from homozygous mouse models using a novel load-clamped laser trap assay. Fmaxwas 50% (R403Q) and 80% (R453C) greater for the HCM mutants compared with the wild type, whereas Fmaxwas severely depressed for one of the DCM mutants (65% S532P). Although Fmaxwas normal for the F764L DCM mutant, its actin-activated ATPase activity and actin filament velocity ( Vactin) in a motility assay were significantly reduced (Schmitt JP, Debold EP, Ahmad F, Armstrong A, Frederico A, Conner DA, Mende U, Lohse MJ, Warshaw D, Seidman CE, Seidman JG. Proc Natl Acad Sci USA 103: 14525–14530, 2006.). These Fmaxdata combined with previous Vactinmeasurements suggest that HCM and DCM result from alterations to one or more of myosin's fundamental mechanical properties, with HCM-causing mutations leading to enhanced but DCM-causing mutations leading to depressed function. These mutation-specific changes in mechanical properties must initiate distinct signaling cascades that ultimately lead to the disparate phenotypic responses observed in HCM and DCM.

Nuclear markers confirm taxonomic status and relationships among highly endangered and closely related right whale species

Right whales (genus: Eubalaena) are among the most endangered mammals, yet their taxonomy and phylogeny have been questioned. A phylogenetic hypothesis based on mitochondrial DNA (mtDNA) variation recently prompted a taxonomic revision, increasing the number of right whale species to three. We critically evaluated this hypothesis using sequence data from 13 nuclear DNA (nuDNA) loci as well as the mtDNA control region. Fixed diagnostic characters among the nuclear markers strongly support the hypothesis of three genetically distinct species, despite lack of any diagnostic morphological characters. A phylogenetics analysis of all data produced a strict consensus cladogram with strong support at nodes that define each right whale species as well as relationships among species. Results showed very little conflict among the individual partitions as well as congruence between the mtDNA and nuDNA datasets. These data clearly demonstrate the strength of using numerous independent genetic markers during a phylogenetics analysis of closely related species. In evaluating phylogenetic support contributed by individual loci, 11 of the 14 loci provided support for at least one of the nodes of interest to this study. Only a single marker (mtDNA control region) provided support at all four nodes. A study using any single nuclear marker would have failed to support the proposed phylogeny, and a strong phylogenetic hypothesis was only revealed by the simultaneous analysis of many nuclear loci. In addition, nu DNA and mtDNA data provided complementary levels of support at nodes of different evolutionary depth indicating that the combined use of mtDNA and nuDNA data is both practical and desirable.

Repeated delivery of adeno-associated virus vectors to the rabbit airway

Efficient local expression from recombinant adeno-associated virus (rAAV)-cystic fibrosis (CF) transmembrane conductance regulator (CFTR) vectors has been observed in the airways of rabbits and monkeys for up to 6 months following a single bronchoscopic delivery. However, it is likely that repeated administrations of rAAV vectors will be necessary for sustained correction of the CF defect in the airways. The current study was designed to test the feasibility of repeated airway delivery of rAAV vectors in the rabbit lung. After two doses of rAAV-CFTR to the airways, rabbits generated high titers of serum anti-AAV neutralizing antibodies. Rabbits then received a third dose of a rAAV vector containing the green fluorescent protein (GFP) reporter gene packaged in either AAV serotype 2 (AAV2) or serotype 3 (AAV3) capsids. Each dose consisted of 1 ml containing 5 x 10(9) DNase-resistant particles of rAAV vector, having no detectable replication-competent AAV or adenovirus. Three weeks later, GFP expression was observed in airway epithelial cells despite high anti-AAV neutralizing titers at the time of delivery. There was no significant difference in the efficiency of DNA transfer or expression between the rAAV3 and rAAV2 groups. No significant inflammatory responses to either repeated airway exposure to rAAV2-CFTR vectors or to GFP expression were observed. These experiments demonstrate that serum anti-AAV neutralizing antibody titers do not predict airway neutralization in vivo and that repeated airway delivery rAAV allows for safe and effective gene transfer.

Jewish beliefs, values, and practices: implications for culturally sensitive nursing care

Providing culturally sensitive nursing care for the Jewish patient is a challenge for the non-Jewish nurse. Understanding the major values, ethics, and practices of Judaism that have relevance to nursing and medical care will give the advanced practice nurse the ability to provide care that is individualized to the patient and family.

A fluorescence video-endoscopy technique for detection of gene transfer and expression

The green fluorescent protein (GFP) has previously been adapted as a reported for gene transfer and expression in mammalian cells in culture and in tissue sections. Herein is described a new method for detecting GFP in situ within epithelia accessible to fiberoptic endoscopy by incorporating fluorescent filters for detection of GFP into an existing fiberoptic endoscopy system. This device was used to detect expression of GFP from adeno-associated virus (AAV; does of 3 x 10(7) IU) and adenovirus (Ad; does of l x 10(9) to 1 x 10(10) p.f.u.) vectors within the bronchial epithelium of New Zealand white rabbits. GFP expression was confirmed by fluorescence-activated cell sorting (FACS), direct fluorescence microscopy of cytospin preparations of brushed cells, and by fluorescence microscopy of fixed tissue sections. This reporter gene/detection system was then used to track the time course of expression of the AAV vector in the bronchial epithelium over the first 30 days after administration. The transduction frequency in the treated region of the epithelium peaked at around 50% at 21 days after transduction. Vector expression was still present at around 20% efficiency at 30 days after administration. This example indicates how this method could be used to reliably track gene transfer in living animals or patients.

Safety of single-dose administration of an adeno-associated virus (AAV)-CFTR vector in the primate lung

Gene therapy for cystic fibrosis (CF) would ideally be accomplished with a vector capable of long-term expression of the cystic fibrosis transmembrane conductance regulator (CFTR) in the absence of a host inflammatory response. Recombinant adeno-associated virus (AAV)-CFTR vectors possess these characteristics in rabbits. Because the utility of AAV vectors as gene transfer agents has only been recognized recently, AAV vector-mediated transduction has never been modeled in a primate host, which is an important step before its use in humans. In order to test the safety and biological activity of AAV-CFTR, single doses of AAV-CFTR vector were administered by fiberoptic bronchoscopy to the posterior basal segment of the right lower lobe (RLL) of the lungs of 10 rhesus macaques with four matched vehicle-treated controls. Animals were followed for 10, 21, 90 or 180 days following vector instillation. Vector DNA transfer occurred in bronchial epithelial cells in the RLL of each animal that received vector as assessed by in situ DNA PCR. Vector mRNA was detectable for 180 days after administration as detected by RT-PCR and by RNase protection assay. Safety of vector administration was determined by measurements of pulmonary mechanics, arterial blood gas analysis, chest radiographs, and bronchoalveolar lavage (BAL) fluid analysis including cell count and quantification of inflammatory cytokines. Gross and microscopic pathologic examination were also performed. There was no evidence of inflammation or other toxicity, although vector DNA was found in extrapulmonary organs of some animals. These results indicate that transduction of the primate airway epithelium with the AAV-CFTR mediates long-term CFTR cDNA transfer and is relatively safe.

Cooperative Learning and Feminist Pedagogy-A Model for Classroom Instruction in Nursing Education

This article reports on a research study conducted as part of a doctoral dissertation on the development of a cooperative learning teaching model in nursing education. The subjects for the study were a convenience sample of registered nurses who were pursuing a baccalaureate degree in nursing at an urban university. Principles of feminist pedagogy were incorporated as part of the cooperative learning model. The teacher/researcher taught two sections of the same course and, through the use of action research, developed a model for using cooperative learning strategies as the primary teaching modality. End of class and end of semester evaluations provided feedback that suggested that this was an exciting and effective alternative to traditional classroom teaching.

Levels of beta-trace protein and lysozyme in human amniotic fluids

The levels of beta-trace protein and lysozyme were estimated in amniotic fluids from normal fetuses and from fetuses with neuraltube defects. The values of these proteins in normal amniotic fluids were found to be similar to those detected in fetuses with anencephaly and spina bifida. The levels of lysozyme were shown to be correlated with gestational age.

Human complement C7 and C9 in fetal and newborn sera

Using specific immune sera, C7, C9, and C3 activator were detected in sera from human fetuses more than 16 weeks old and in newborn samples. Levels of C9 in cord sera ranged between 10 and 30% of those present in sera from adult subjects. The mean value of Ce activator was about half that in maternal blood. The mean level of C7 in newborns was nearly 70% of the amount in normal adults.