COVID-19 vaccine efficacy in participants with weakened immune systems from four randomized-controlled trials

BACKGROUND

Although the SARS-CoV-2 vaccines are highly efficacious at preventing severe disease in the general population, current data are lacking regarding vaccine efficacy (VE) for individuals with mild immunocompromising conditions.

METHODS

A post-hoc, cross-protocol analysis of participant-level data from the blinded phase of four randomized, placebo-controlled, COVID-19 vaccine phase 3 trials (Moderna, AstraZeneca, Janssen, and Novavax) was performed. We defined a "tempered immune system" (TIS) variable via a consensus panel based on medical history and medications to determine VE against symptomatic and severe COVID-19 cases in TIS participants versus non-TIS (NTIS) individuals starting at 14 days after completion of the primary series through the blinded phase for each of the four trials. An analysis of participants living with well-controlled HIV was conducted using the same methods.

RESULTS

3,852/30,351 (12.7%) Moderna participants, 3,088/29,868 (10.3%) Novavax participants, 3,549/32,380 (11.0%) AstraZeneca participants, and 5,047/43,788 (11.5%) Janssen participants were identified as having a TIS. Most TIS conditions (73.9%) were due to metabolism and nutritional disorders. Vaccination (versus placebo) significantly reduced the likelihood of symptomatic and severe COVID-19 for all participants for each trial. VE was not significantly different for TIS participants vs NTIS for either symptomatic or severe COVID-19 for each trial, nor was VE significantly different in the symptomatic endpoint for participants with HIV.

CONCLUSIONS

For individuals with mildly immunocompromising conditions, there is no evidence of differences in VE against symptomatic or severe COVID-19 compared to those with non-tempered immune systems in the four COVID-19 vaccine randomized controlled efficacy trials.

More than one way to improve a CAT: Outcomes and reflections on two iterations of the Queen Square Intensive Comprehensive Aphasia Programme

Background

The field of human expert performance teaches us that high quality, high-dose guided practice is required to make large gains in cognitively driven acts. The same also seems to be true for people with acquired brain injury, yet therapy services for people with aphasia (PWA) have traditionally not been designed with this in mind. Intensive Comprehensive Aphasia Programmes (ICAPs) are one way to address the chronic under-dosing of therapy that most PWA experience.

Aims

There are several ways to deliver an ICAP; here we describe two iterations of our Queen Square ICAP. There was a 20-month COVID-induced pause between the Year 1 (Y1) and Year 2 (Y2) ICAP groups. We analyse ICAP-induced changes in both groups of PWA on a series of key outcome measures that span the International Classification of Functioning, Disability and Health, covering language impairment and function as well as mood and social participation.

Methods & Procedures

Forty-six PWA took part in Y1 and 44 in Y2. The PWA were all in the chronic stage post stroke and varied in aphasia severity from mild to severe, with the Y2 group being more impaired than Y1. Quantitative data was collected before and after the ICAP. The Y2 therapy team provided independent reflections on their experiences of delivering an ICAP.

Outcomes & Results

ICAP-related changes in outcome measures (impairment, function and goal attainment) were generally comparable for the Y1 and Y2 groups, with both groups' speech production abilities improving the most. Both groups made clinically and statistically significant gains on the main quality of life measure. Participation in the ICAP made a big difference to PWAs' self-confidence ratings. Their mood ratings also improved significantly, although they were not, on average, in the depressed range at baseline (directly pre-ICAP). All improvements achieved in both groups were maintained at the 3-month follow-up, highlighting the lasting effects that ICAPs can provide.

Conclusions

Evidence continues to accrue that ICAPs are an efficient way of increasing the dose of expert coaching required for people with chronic aphasia to make clinically meaningful improvements in their communicative abilities and quality of life. The main challenge remaining is convincing health-care providers to invest in them.

Bivalent and Monovalent SARS-CoV-2 Variant Vaccine Boosters Improve coverage of the known Antigenic Landscape: Results of the COVID-19 Variant Immunologic Landscape (COVAIL) Trial

Vaccine protection against COVID-19 wanes over time and has been impacted by the emergence of new variants with increasing escape of neutralization. The COVID-19 Variant Immunologic Landscape (COVAIL) randomized clinical trial (clinicaltrials.gov NCT05289037) compares the breadth, magnitude and durability of antibody responses induced by a second COVID-19 vaccine boost with mRNA (Moderna mRNA-1273 and Pfizer-BioNTech BNT162b2), or adjuvanted recombinant protein (Sanofi CoV2 preS DTM-AS03) monovalent or bivalent vaccine candidates targeting ancestral and variant SARS-CoV-2 spike antigens (Beta, Delta and Omicron BA.1). We found that boosting with a variant strain is not associated with loss in neutralization against the ancestral strain. However, while variant vaccines compared to the prototype/wildtype vaccines demonstrated higher neutralizing activity against Omicron BA.1 and BA.4/5 subvariants for up to 3 months after vaccination, neutralizing activity was lower for more recent Omicron subvariants. Our study, incorporating both antigenic distances and serologic landscapes, can provide a framework for objectively guiding decisions for future vaccine updates.

An Oil-in-Water adjuvant significantly increased influenza A/H7N9 split virus Vaccine-Induced circulating follicular helper T (cTFH) cells and antibody responses

BACKGROUND

Unadjuvanted A/H7N9 vaccines are poorly immunogenic. The immune response is improved with the addition of MF59, an oil-in-water adjuvant. However, the cellular immunologic responses of MF59-adjuvanted A/H7N9 vaccine are not fully understood.

METHODS

37 participants were vaccinated with 2 doses of 2013 influenza A/H7N9 vaccine (at Days 1 and 21) with or without MF59 and enrolled in an immunology substudy. Responses were assessed at multiple timepoints (Days 0, 8, 21, 29, and 42) for hemagglutination inhibition (HAI) and neutralizing antibody (Neut) assays, memory B cell responses by enzyme-linked ImmunoSpot; circulating follicular helper T cells (cT_FH) and CD4 + T cells by intracellular cytokine staining.

RESULTS

MF59-adjuvanted influenza A/H7N9 vaccine induced significantly higher hemagglutination inhibition (HAI) and neutralizing antibody (Neut) responses when compared to unadjuvanted vaccine. The adjuvanted vaccine elicited significantly higher levels of Inducible T-cell Co-Stimulator (ICOS) expression by CXCR3⁺CXCR5⁺CD4⁺ cT_FH cells, compared to unadjuvanted vaccine. The magnitude of increase in cT_FH cells (from baseline to Day 8) and in IL-21 expressing CD154⁺CD4⁺ T cells (from baseline to Days 8 and 21) correlated with HAI (at Day 29) and Neut antibody (at Days 8 and 29) titers. The increase in frequency of IL-21 expressing CD154⁺CD4⁺T cells (from baseline to Day 21) correlated with memory B cell frequency (at Day 42).

CONCLUSION

cT_FH activation is associated with HAI and Neut responses in recipients of MF59-adjuvanted influenza A/H7N9 vaccine relative to unadjuvanted vaccine. Future studies should focus on optimizing the cT_FH response and use cT_FH as an early biomarker of serological response to vaccination. This trial was registered at clinicaltrials.gov, trial number NCT01938742.

Safety and immunogenicity of a trivalent virus-like particle vaccine against western, eastern, and Venezuelan equine encephalitis viruses: a phase 1, open-label, dose-escalation, randomised clinical trial

BACKGROUND

Western (WEEV), eastern (EEEV), and Venezuelan (VEEV) equine encephalitis viruses are mosquito-borne pathogens classified as potential biological warfare agents for which there are currently no approved human vaccines or therapies. We aimed to evaluate the safety, tolerability, and immunogenicity of an investigational trivalent virus-like particle (VLP) vaccine, western, eastern, and Venezuelan equine encephalitis (WEVEE) VLP, composed of WEEV, EEEV, and VEEV VLPs.

METHODS

The WEVEE VLP vaccine was evaluated in a phase 1, randomised, open-label, dose-escalation trial at the Hope Clinic of the Emory Vaccine Center at Emory University, Atlanta, GA, USA. Eligible participants were healthy adults aged 18-50 years with no previous vaccination history with an investigational alphavirus vaccine. Participants were assigned to a dose group of 6 μg, 30 μg, or 60 μg vaccine product and were randomly assigned (1:1) to receive the WEVEE VLP vaccine with or without aluminium hydroxide suspension (alum) adjuvant by intramuscular injection at study day 0 and at week 8. The primary outcomes were the safety and tolerability of the vaccine (assessed in all participants who received at least one administration of study product) and the secondary outcome was immune response measured as neutralising titres by plaque reduction neutralisation test (PRNT) 4 weeks after the second vaccination. This trial is registered at ClinicalTrials.gov, NCT03879603.

FINDINGS

Between April 2, 2019, and June 13, 2019, 30 trial participants were enrolled (mean age 32 years, range 21-48; 16 [53%] female participants and 14 [47%] male participants). Six groups of five participants each received 6 μg, 30 μg, or 60 μg vaccine doses with or without adjuvant, and all 30 participants completed study follow-up. Vaccinations were safe and well tolerated. The most frequently reported symptoms were mild injection-site pain and tenderness (22 [73%] of 30) and malaise (15 [50%] of 30). Dose-dependent differences in the frequency of pain and tenderness were found between the 6 μg, 30 μg, and 60 μg groups (p=0·0217). No significant differences were observed between dosing groups for any other reactogenicity symptom. Two adverse events (mild elevated blood pressure and moderate asymptomatic neutropenia) were assessed as possibly related to the study product in one trial participant (60 μg dose with alum); both resolved without clinical sequelae. 4 weeks after second vaccine administration, neutralising antibodies were induced in all study groups with the highest response seen against all three vaccine antigens in the 30 μg plus alum group (PRNT₈₀ geometric mean titre for EEEV 60·8, 95% CI 29·9-124·0; for VEEV 111·5, 49·8-249·8; and for WEEV 187·9, 90·0-392·2). Finally, 4 weeks after second vaccine administration, for all doses, the majority of trial participants developed an immune response to all three vaccine components (24 [83%] of 29 for EEEV; 26 [90%] of 29 for VEEV; 27 [93%] of 29 for WEEV; and 22 [76%] of 29 for EEEV, VEEV, and WEEV combined).

INTERPRETATION

The favourable safety profile and neutralising antibody responses, along with pressing public health need, support further evaluation of the WEVEE VLP vaccine in advanced-phase clinical trials.

FUNDING

The Vaccine Research Center of the National Institute of Allergy and Infectious Diseases, National Institutes of Health funded the clinical trial. The US Department of Defense contributed funding for manufacturing of the study product.

Immunologic mechanisms of seasonal influenza vaccination administered by microneedle patch from a randomized phase I trial

In a phase 1 randomized, single-center clinical trial, inactivated influenza virus vaccine delivered through dissolvable microneedle patches (MNPs) was found to be safe and immunogenic. Here, we compare the humoral and cellular immunologic responses in a subset of participants receiving influenza vaccination by MNP to the intramuscular (IM) route of administration. We collected serum, plasma, and peripheral blood mononuclear cells in 22 participants up to 180 days post-vaccination. Hemagglutination inhibition (HAI) titers and antibody avidity were similar after MNP and IM vaccination, even though MNP vaccination used a lower antigen dose. MNPs generated higher neuraminidase inhibition (NAI) titers for all three influenza virus vaccine strains tested and triggered a larger percentage of circulating T follicular helper cells (CD4 + CXCR5 + CXCR3 + ICOS + PD-1+) compared to the IM route. Our study indicates that inactivated influenza virus vaccination by MNP produces humoral and cellular immune response that are similar or greater than IM vaccination.

Clinical Effectiveness of the Queen Square Intensive Comprehensive Aphasia Service for Patients With Poststroke Aphasia

Supplemental Digital Content is available in the text.

Poststroke aphasia has a major impact on peoples’ quality of life. Speech and language therapy interventions work, especially in high doses, but these doses are rarely achieved outside of research studies. Intensive Comprehensive Aphasia Programs (ICAPs) are an option to deliver high doses of therapy to people with aphasia over a short period of time.

Clinical characteristics and outcomes of toxoplasmosis among transplant recipients at two US academic medical centers

Toxoplasma gondii can cause severe opportunistic infection in immunocompromised individuals, but diagnosis is often delayed. We conducted a retrospective review of solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients with toxoplasmosis between 2002 and 2018 at two large US academic transplant centers. Patients were identified by ICD-9 or ICD-10 toxoplasmosis codes, positive Toxoplasma polymerase chain reaction test result, or pathologic diagnosis. Data were collected regarding transplant type, time from transplant to toxoplasmosis diagnosis, clinical and radiographic features, and mortality at 30 and 90 days. Twenty patients were identified: 10 HSCT recipients (80% allogeneic HSCT) and 10 SOT recipients (60% deceased donor renal transplants). Rejection among SOT recipients (70%) and graft-versus-host disease (GVHD) prophylaxis among HSCT recipients (50%) were frequent. Median time from transplant to toxoplasmosis diagnosis was longer for SOT than HSCT (1385 vs. 5 days, P-value .002). Clinical manifestations most commonly were encephalitis (65%), respiratory failure (40%), renal failure (40%), and distributive shock (40%). Cohort 30-day mortality was 45%, and 90-day mortality was 55%. Diagnosis was postmortem in 25% of the cohort. Further evaluation of toxoplasmosis screening is needed for noncardiac SOT recipients, HSCT recipients with GVHD, and periods of increased net immunosuppression.

2693. Clinical Presentation of Toxoplasmosis and 30-Day Mortality in Transplant Recipients at Two Academic Medical Centers

Background

Toxoplasma gondii causes opportunistic infections in transplant recipients after primary, donor-derived, or reactivated infection. Diagnosis in solid-organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients may be delayed due to varied clinical presentations, which can mimic bacterial sepsis. These delays could contribute to significant associated mortality, with a reported rate exceeding 50% in disseminated disease. Further exploration of expanded donor screening, targeted recipient prophylaxis, and enhanced early detection may be warranted. We therefore examined patient characteristics, clinical presentation, time to toxoplasmosis diagnosis, and mortality in transplant recipients at two centers.

Methods

A retrospective chart review of SOT and HSCT recipients diagnosed with toxoplasmosis from 2002–2018 at Emory Healthcare and Duke University Hospital was performed, with cases identified via an electronic query of relevant ICD codes, positive serum or CSF toxoplasmosis PCRs, and pathologic diagnoses. Patient characteristics, including age, sex, race, time since transplantation, method of toxoplasmosis diagnosis, and symptoms, were abstracted. Primary outcomes included time from transplant to diagnosis and estimated 30- and 90-day all-cause mortality.

Results

16 patients were identified, with a median age of 56 years at diagnosis. 50% were male, and the majority were white (63%) and SOT recipients (56%; see table). Median time from transplant to diagnosis was 295 days, with PCR the most common diagnostic modality (63%). In 31% of cases, toxoplasmosis was diagnosed after patient death. The most common clinical presentations were encephalitis (69%), respiratory failure (63%), renal failure (50%), diarrhea (50%), and septic shock (50%). The estimated all-cause 30-day and 90-day mortality rates were 56% and 69%, respectively.

Conclusion

Toxoplasmosis has diverse presentations in transplant recipients, likely contributing to diagnostic delays and high mortality. Future study is needed to determine clinical scenarios and risk factors where donor and recipient serologic screening may beneficial.

Disclosures

All authors: No reported disclosures.

Influence of spin and charge fluctuations on spectra of the two-dimensional Hubbard model

The influence of spin and charge fluctuations on spectra of the two-dimensional fermionic Hubbard model is considered using the strong coupling diagram technique. Infinite sequences of diagrams containing ladder inserts, which describe the interaction of electrons with these fluctuations, are summed, and obtained equations are self-consistently solved for the ranges of Hubbard repulsions [Formula: see text], temperatures [Formula: see text] and electron concentrations [Formula: see text] with t the intersite hopping constant. For all considered U the system exhibits a transition to the long-range antiferromagnetic order at [Formula: see text]. At the same time no indication of charge ordering is observed. Obtained solutions agree satisfactorily with results of other approaches and obey moments sum rules. In the considered region of the U-T plane, the curve separating metallic solutions passes from [Formula: see text] at the highest temperatures to U  =  2t at [Formula: see text] for half-filling. If only short-range fluctuations are allowed for the remaining part of this region is occupied by insulating solutions. Taking into account long-range fluctuations leads to strengthening of maxima tails, which transform a part of insulating solutions into bad-metal states. For low T, obtained results allow us to trace the gradual transition from the regime of strong correlations with the pronounced four-band structure and well-defined Mott gap for [Formula: see text] to the Slater regime of weak correlations with the spectral intensity having a dip along the boundary of the magnetic Brillouin zone due to an antiferromagnetic ordering for [Formula: see text]. For [Formula: see text] and [Formula: see text] doping leads to the occurrence of a pseudogap near the Fermi level, which is a consequence of the splitting out of a narrow band from a Hubbard subband. Obtained spectra feature waterfalls and Fermi arcs, which are similar to those observed in hole-doped cuprates.

The Temperature Response and Aggressiveness of Peyronellaea pinodes Isolates Originating from Wild and Domesticated Pisum sp. in Israel

Domesticated pea fields are grown in relatively close proximity to wild pea species in Israel. Despite the major role attributed to ascochyta blight in causing yield losses in domesticated pea, very limited information is available on the pathogens prevailing in natural ecosystems. The objectives of this study were (i) to identify the species causing ascochyta blight symptoms on leaves, stems, and petioles of domesticated pea and wild Pisum plants in Israel, and (ii) to quantify the temperature response(s) and aggressiveness of such pathogens originating from Pisum plants growing in sympatric and allopatric contexts. Eighteen fungal isolates were examined and identified; three of them were sampled from Pisum sativum, 11 from Pisum fulvum, and four from Pisum elatius. All isolates were identified as Peyronellaea pinodes. Spore germination and mycelial growth took place over a wide range of temperatures, the lower and upper cardinal temperatures being 2 to 9 and 33 to 38°C, respectively; the optimal temperatures ranged from 22 to 26°C. At an optimal temperature, disease severity was significantly higher for plants maintained under moist conditions for 24 h postinoculation than for those exposed to humidity for 5 or 10 h. Analyses of the data revealed that temperature responses, spore germination rates, and aggressiveness of isolates sampled from domesticated pea plants did not differ from those of isolates sampled from adjacent or distant wild populations. Host specificity was not observed. These observations suggest that Israel may be inhabited by a single metapopulation of P. pinodes.

Cryopreservation of specialized chicken lines using cultured primordial germ cells

Biosecurity and sustainability in poultry production requires reliable germplasm conservation. Germplasm conservation in poultry is more challenging in comparison to other livestock species. Embryo cryopreservation is not feasible for egg-laying animals, and chicken semen conservation has variable success for different chicken breeds. A potential solution is the cryopreservation of the committed diploid stem cell precursors to the gametes, the primordial germ cells ( PGCS: ). Primordial germ cells are the lineage-restricted cells found at early embryonic stages in birds and form the sperm and eggs. We demonstrate here, using flocks of partially inbred, lower-fertility, major histocompatibility complex- ( MHC-: ) restricted lines of chicken, that we can easily derive and cryopreserve a sufficient number of independent lines of male and female PGCs that would be sufficient to reconstitute a poultry breed. We demonstrate that germ-line transmission can be attained from these PGCs using a commercial layer line of chickens as a surrogate host. This research is a major step in developing and demonstrating that cryopreserved PGCs could be used for the biobanking of specialized flocks of birds used in research settings. The prospective application of this technology to poultry production will further increase sustainability to meet current and future production needs.

Immune responses to human factor IX in haemophilia B mice of different genetic backgrounds are distinct and modified by TLR4

Our laboratory develops protocols to prevent or reverse ongoing anti-hFIX IgG inhibitors in haemophilia B mice with a F9 gene deletion on BALB/c and C3H/HeJ backgrounds. C3H/HeJ F9^−/Y mice develop high titre anti-hFIX IgG1 inhibitors and anaphylaxis, whereas most BALB/c F9^−/Y mice have mild anti-hFIX IgG1 inhibitors and no anaphylaxis. Our aim was to determine if hFIX-specific B- and T-cell responses in BALB/c and C3H/HeJ F9^−/Y mice trigger the difference in anti-hFIX immune responses. BALB/c and C3H/HeJ F9^−/Y mice were challenged weekly with recombinant hFIX protein. Humoral immune responses were determined by IgG1 and IgG2a anti-hFIX ELISA, Bethesda assay for inhibitors and B-cell ELISpot on bone marrow and spleen cells. T-cell studies measured the T_H1 (IFN-γ) and T_H2 (IL-4) cytokine responses in splenocytes at the mRNA and protein level in response to hFIX protein. Antibody responses were also measured in C3H/HeJ/OuJ F9^−/Y mice with restored toll-like receptor 4 (TLR4) function. BALB/c F9^−/Y mice have a T_H2 skewed response and a reduction in anti-hFIX secreting plasma cells in the bone marrow. Independent antigen challenge revealed both strains generated equivalent IgG1 antibody titres to an intravenously delivered antigen. C3H/HeJ F9^−/Y mice have a mixed T_H1 and T_H2 response (mainly T_H2). Importantly, TLR4 signalling has a modulatory role in the C3H background on the levels of anti-hFIX IgG1 and incidence of anaphylaxis. The background strain strongly impacts the immune response to hFIX, which can be significantly impacted by mutations in innate immune sensors.

Treatment of hepatitis C: a systematic review

IMPORTANCE

Hepatitis C virus (HCV) infects more than 185 million individuals worldwide. Twenty percent of patients chronically infected with HCV progress to cirrhosis. New, simpler therapeutics using direct-acting antivirals that target various stages of the HCV life cycle are in development to eradicate HCV without concomitant interferon.

OBJECTIVES

To summarize published evidence on safety, efficacy (measured by a sustained virologic response [SVR], which is the treatment goal of undetectable plasma HCV RNA 12 or 24 weeks after therapy completion), and tolerability of current US Food and Drug Administration-approved interferon-based regimens and oral interferon-free regimens used for treating HCV infection and coinfection with human immunodeficiency virus (HIV) and HCV; to provide treatment recommendations for specialists and generalists based on published evidence.

EVIDENCE REVIEW

A literature search of Web of Science, Scopus, Embase, Agricola, Cochrane Library, Cinahl Plus, ClinicalTrials.gov, Conference Papers Index, Gideon, PsycINFO, Google Scholar, and Oaister was conducted from January 1, 2009, to May 30, 2014. Publications describing phase 2, 3, and 4 studies evaluating the treatment of HCV were included. Forty-one studies involving 19,063 adult patients were included. Strength of clinical data and subsequent HCV treatment recommendations were graded according to the Oxford Centre for Evidence-Based Medicine.

FINDINGS

Patients infected with HCV genotype 1 represent 60% to 75% of HCV infections in the United States. Hepatitis C virus genotype 1 is more difficult to cure than genotype 2 or genotype 3. Patients with HCV genotype 1 should receive treatment with sofosbuvir + pegylated interferon + ribavirin because of the shorter duration of therapy and high rates of SVR (89%-90%). Simeprevir + pegylated interferon + ribavirin is an alternative for patients with HCV genotype 1 (SVR, 79%-86%). Patients with HCV genotypes 2 and 3, representing 20% to 29% of US HCV infections, should receive therapy with sofosbuvir + ribavirin alone (SVR for genotype 2, 12 weeks' duration: 82%-93%; SVR for genotype 3, 24 weeks' duration, 80%-95%). Patients with HIV-HCV coinfection and patients with compensated cirrhosis (ie, cirrhosis but preserved synthetic liver function) should receive the same treatment as HCV-monoinfected patients.

CONCLUSIONS AND RELEVANCE

New, short-duration, simpler therapies result in high SVR rates for HCV-infected patients. In conjunction with increased screening for HCV as suggested by recent Centers for Disease Control and Prevention guidelines, availability of new therapies may lead to the treatment of many more people with chronic HCV infection.

Subcutaneous adipose cell size and distribution: relationship to insulin resistance and body fat

OBJECTIVE

Metabolic heterogeneity among obese individuals may be attributable to differences in adipose cell size. We sought to clarify this by quantifying adipose cell size distribution, body fat, and insulin-mediated glucose uptake in overweight to moderately-obese individuals.

METHODS

A total of 148 healthy nondiabetic subjects with BMI 25-38 kg/m2 underwent subcutaneous adipose tissue biopsies and quantification of insulin-mediated glucose uptake with steady-state plasma glucose (SSPG) concentrations during the modified insulin suppression test. Cell size distributions were obtained with Beckman Coulter Multisizer. Primary endpoints included % small adipose cells and diameter of large adipose cells. Cell-size and metabolic parameters were compared by regression for the whole group, according to insulin-resistant (IR) and insulin-sensitive (IS) subgroups, and by body fat quintile.

RESULTS

Both large and small adipose cells were present in nearly equal proportions. Percent small cells was associated with SSPG (r = 0.26, P = 0.003). Compared to BMI-matched IS individuals, IR counterparts demonstrated fewer, but larger large adipose cells, and a greater proportion of small-to-large adipose cells. Diameter of the large adipose cells was associated with % body fat (r = 0.26, P = 0.014), female sex (r = 0.21, P = 0.036), and SSPG (r = 0.20, P = 0.012). In the highest versus lowest % body fat quintile, adipose cell size increased by only 7%, whereas adipose cell number increased by 74%.

CONCLUSIONS

Recruitment of adipose cells is required for expansion of body fat mass beyond BMI of 25 kg/m2 . Insulin resistance is associated with accumulation of small adipose cells and enlargement of large adipose cells. These data support the notion that impaired adipogenesis may underlie insulin resistance.

Feline mammary carcinoma stem cells are tumorigenic, radioresistant, chemoresistant and defective in activation of the ATM/p53 DNA damage pathway

Cancer stem cells were identified in a feline mammary carcinoma cell line by demonstrating expression of CD133 and utilising the tumour sphere assay. A population of cells was identified that had an invasive, mesenchymal phenotype, expressed markers of pluripotency and enhanced tumour formation in the NOD-SCID mouse and chick embryo models. This population of feline mammary carcinoma stem cells was resistant to chemotherapy and radiation, possibly due to aberrant activation of the ATM/p53 DNA damage pathway. Epithelial–mesenchymal transition was a feature of the invasive phenotype. These data demonstrate that cancer stem cells are a feature of mammary cancer in cats.

Distinct and overlapping genomic profiles and antiviral effects of Interferon-λ and -α on HCV-infected and noninfected hepatoma cells

Recently, several SNPs in the region of the IL28B (IFN-λ) gene have been associated with spontaneous clearance of hepatitis C virus (HCV) and enhanced cure rates for IFN-alfa-based therapies, suggesting a potential correlation between IFN-λ and the ability to clear HCV. To understand the mechanism of IFN-λ's as compared to IFN-α's antiviral activity, we performed a comprehensive analysis of their anti-HCV effects, whole genome transcriptome profiling with validation, and signalling of IFN-α and IFN-λ using J6/JFH-1 and Huh7.5 cells in vitro. IFN-λ and IFN-α exhibited comparable anti-HCV activity and gene expression profiles in Huh7.5 cells. While the majority of genes induced by IFN-α and IFN-λ were similar, IFN-λ exhibits profound, but delayed kinetics of IFN-stimulated genes (ISG) induction, while IFN-α induced more rapid induction of ISGs. Furthermore, the increased induction of ISG expression by IFN-λ correlated with up-regulation of IFN-λ receptor (IL-28RA) expression and more prolonged activation of the Jak-STAT signalling pathway. The findings from our comparative analysis of IFN-α and IFN-λ in HCV-infected and noninfected cells support the clinical use of IFN-λ as a potential alternative to IFN-α in the treatment of chronic hepatitis C.

Role of nitrogen-metabolism genes expressed during pathogenicity of the alkalinizing Colletotrichum gloeosporioides and their differential expression in acidifying pathogens

Pathogens can actively alter fruit pH around the infection site, signaling modulation of pathogenicity-factor expression, as found for alkalinizing (Colletotrichum and Alternaria spp.) and acidifying (Penicillium, Botrytis, and Sclerotinia spp.) fungi. The nitrogen-metabolism genes GDH2, GS1, GLT, and MEP genes are differentially expressed during colonization by Colletotrichum gloeosporioides, and a Δgdh2 strain reduces ammonia accumulation and pathogenicity. We analyzed the contribution of transporters GLT and MEPB to C. gloeosporiodes pathogenicity. Germinating spores of Δglt strains showed reduced appressorium formation; those of ΔmepB mutants showed rapid ammonia uptake and accumulation inside the hyphae, indicating deregulated uptake. Both mutants reduced pathogenicity, indicating that these transporters function during alkalinizing species pathogenicity. We compared the expressions of these genes in C. gloeosporioides and Sclerotinia sclerotiorum, and found five to 10-fold higher expression at the transcript level in the former. Interestingly, GLT and MEPB in the alkalinizing species showed no and very low sequence identity, respectively, with their counterparts in the acidifying species. Knockout analysis of GLT and MEPB and their differential transcript regulation in the alkalinizing and acidifying species suggest that the ammonia accumulation contributing to pathogenicity in the former is modulated by factors at the gene-regulation levels that are lacking in the acidifying species.

Diffusively coupled bursters: effects of cell heterogeneity

The interaction of a pair of weakly coupled biological bursters is examined.Bursting refers to oscillations in which an observable slowly alternates between phases of relative quiescence and rapid oscillatory behavior. The motivation for this work is to understand the role of electrical coupling in promoting the synchronization of bursting electrical activity (BEA) observed in the -cells of the islet of Langerhans, which secrete insulin in response to glucose. By studying the coupled fast subsystem of a model of BEA, we focus on the interaction that occurs during the rapid oscillatory phase. Coupling is weak, diffusive and non-scalar. In addition,non-identical oscillators are permitted. Using perturbation methods with the assumption that the uncoupled oscillators are near a Hopf bifurcation, a reduced system of equations is obtained. A detailed bifurcation study of this reduced system reveals a variety of patterns but suggests that asymmetrically phase-locked solutions are the most typical. Finally, the results are applied to the unreduced full bursting system and used to predict the burst pattern for a pair of cells with a given coupling strength and degree of heterogeneity.

The t-J model on a semi-infinite lattice

The hole spectral function of the t-J model on a two-dimensional semi-infinite lattice is calculated using the spin-wave and non-crossing approximations. In the case of small hole concentrations and strong correlations, t >> J, several near-boundary site rows appear to be depleted of holes. The reason is a deformation of the magnon cloud, which surrounds the hole, near the boundary. The hole depletion leads to a more complicated spectral function in the boundary row in comparison with its bulk shape. This is connected with a maximum related to the underlying row, which reveals itself in the boundary spectrum.

A genetic map of melon highly enriched with fruit quality QTLs and EST markers, including sugar and carotenoid metabolism genes

A genetic map of melon enriched for fruit traits was constructed, using a recombinant inbred (RI) population developed from a cross between representatives of the two subspecies of Cucumis melo L.: PI 414723 (subspecies agrestis) and 'Dulce' (subspecies melo). Phenotyping of 99 RI lines was conducted over three seasons in two locations in Israel and the US. The map includes 668 DNA markers (386 SSRs, 76 SNPs, six INDELs and 200 AFLPs), of which 160 were newly developed from fruit ESTs. These ESTs include candidate genes encoding for enzymes of sugar and carotenoid metabolic pathways that were cloned from melon cDNA or identified through mining of the International Cucurbit Genomics Initiative database (http://www.icugi.org/). The map covers 1,222 cM with an average of 2.672 cM between markers. In addition, a skeleton physical map was initiated and 29 melon BACs harboring fruit ESTs were localized to the 12 linkage groups of the map. Altogether, 44 fruit QTLs were identified: 25 confirming QTLs described using other populations and 19 newly described QTLs. The map includes QTLs for fruit sugar content, particularly sucrose, the major sugar affecting sweetness in melon fruit. Six QTLs interacting in an additive manner account for nearly all the difference in sugar content between the two genotypes. Three QTLs for fruit flesh color and carotenoid content were identified. Interestingly, no clear colocalization of QTLs for either sugar or carotenoid content was observed with over 40 genes encoding for enzymes involved in their metabolism. The RI population described here provides a useful resource for further genomics and metabolomics studies in melon, as well as useful markers for breeding for fruit quality.

Pioglitazone increases the proportion of small cells in human abdominal subcutaneous adipose tissue

Rodent and in vitro studies suggest that thiazolidinediones promote adipogenesis but there are few studies in humans to corroborate these findings. The purpose of this study was to determine whether pioglitazone stimulates adipogenesis in vivo and whether this process relates to improved insulin sensitivity. To test this hypothesis, 12 overweight/obese nondiabetic, insulin-resistant individuals underwent biopsy of abdominal subcutaneous adipose tissue at baseline and after 12 weeks of pioglitazone treatment. Cell size distribution was determined via the Multisizer technique. Insulin sensitivity was quantified at baseline and postpioglitazone by the modified insulin suppression test. Regional fat depots were quantified by computed tomography (CT). Insulin resistance (steady-state plasma insulin and glucose (SSPG)) decreased following pioglitazone (P < 0.001). There was an increase in the ratio of small-to-large cells (1.16 +/- 0.44 vs. 1.52 +/- 0.66, P = 0.03), as well as a 25% increase in the absolute number of small cells (P = 0.03). The distribution of large cell diameters widened (P = 0.009), but diameter did not increase in the case of small cells. The increase in proportion of small cells was associated with the degree to which insulin resistance improved (r = -0.72, P = 0.012). Visceral abdominal fat decreased (P = 0.04), and subcutaneous abdominal (P = 0.03) and femoral fat (P = 0.004) increased significantly. Changes in fat volume were not associated with SSPG change. These findings demonstrate a clear effect of pioglitazone on human subcutaneous adipose cells, suggestive of adipogenesis in abdominal subcutaneous adipose tissue, as well as redistribution of fat from visceral to subcutaneous depots, highlighting a potential mechanism of action for thiazolidinediones. These findings support the hypothesis that defects in subcutaneous fat storage may underlie obesity-associated insulin resistance.