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Despite investigations for over 70 years, the absolute limits of human vision have remained unclear. Rod cells respond to individual photons, yet whether a single-photon incident on the eye can be perceived by a human subject has remained a fundamental open question. Here we report that humans can detect a single-photon incident on the cornea with a probability significantly above chance. This was achieved by implementing a combination of a psychophysics procedure with a quantum light source that can generate single-photon states of light. We further discover that the probability of reporting a single photon is modulated by the presence of an earlier photon, suggesting a priming process that temporarily enhances the effective gain of the visual system on the timescale of seconds.

The United States Immunodeficiency Network (USIDNET) patient registry was used to characterize the presentation, genetics, phenotypes, and treatment of patients with Hyper IgM Syndrome (HIGM). The USIDNET Registry was queried for HIGM patient data collected from October 1992 to July 2015. Data fields included demographics, criteria for diagnosis, pedigree analysis, mutations, clinical features, treatment and transplant records, laboratory findings, and mortality. Fifty-two physicians entered data from 145 patients of ages 2 months to 62 years (median 12 years); 131 were males. Using patients' age at last entry, data from 2072 patient years are included. Mutations were recorded for 85 subjects; 82 were in CD40LG. Eighteen subjects had non-X-linked HIGM. 40 % had a normal serum IgM and 15 %, normal IgA. Infections were reported for 91 %, with pulmonary, ear, and sinus infections being the most common. 42 % had Pneumocystis jirovecii pneumonia; 6 % had Cryptosporidium. 41 % had neutropenia. 78 % experienced non-infectious complications: chronic diarrhea (n = 22), aphthous ulcers (n = 28), and neoplasms (n = 8) including colon cancer, adrenal adenoma, liver adenocarcinoma, pancreatic carcinoid, acute myeloid leukemia, hepatoma, and, in a female with an autosomal dominant gain of function mutation in PIK3CD, an ovarian dysgerminoma. Thirteen patients had a hematopoietic marrow or stem cell transplant; three had solid organ transplants. Thirteen were known to have died (median age = 14 years). Analysis of the USIDNET Registry provides data on the common clinical features of this rare syndrome, and in contrast with previously published data, demonstrates longer survival times and reduced gastrointestinal manifestations.

Recent analysis demonstrates that the HIV-1 Long Terminal Repeat (HIV LTR) promoter exhibits a range of possible transcriptional burst sizes and frequencies for any mean-expression level. However, these results have also been interpreted as demonstrating that cell-tocell expression variability (noise) and mean are uncorrelated, a significant deviation from previous results. Here, we re-examine the available mRNA and protein abundance data for the HIV LTR and find that noise in mRNA and protein expression scales inversely with the mean along analytically predicted transcriptional burst-sizemanifolds. We then experimentally perturb transcriptional activity to test a prediction of the multiple burst-size model: that increasing burst frequency will cause mRNA noise to decrease along given burst-size lines as mRNA levels increase. The data show that mRNA and protein noise decrease as mean expression increases, supporting the canonical inverse correlation between noise and mean.

Whether beta(1) integrin ectodomains visit conformational states similarly to beta(2) and beta(3) integrins has not been characterized. Furthermore, despite a wealth of activating and inhibitory antibodies to beta(1) integrins, the conformational states that these antibodies stabilize, and the relation of these conformations to function, remain incompletely characterized. Using negative-stain electron microscopy, we show that the integrin alpha(5)beta(1) ectodomain adopts extended-closed and extended-open conformations as well as a bent conformation. Antibodies SNAKA51, 8E3, N29, and 9EG7 bind to different domains in the alpha(5) or beta(1) legs, activate, and stabilize extended ectodomain conformations. Antibodies 12G10 and HUTS-4 bind to the beta(1) beta I domain and hybrid domains, respectively, activate, and stabilize the open headpiece conformation. Antibody TS2/16 binds a similar epitope as 12G10, activates, and appears to stabilize an open beta I domain conformation without requiring extension or hybrid domain swing-out. mAb13 and SG/19 bind to the beta I domain and beta I-hybrid domain interface, respectively, inhibit, and stabilize the closed conformation of the headpiece. The effects of the antibodies on cell adhesion to fibronectin substrates suggest that the extended-open conformation of alpha(5)beta(1) is adhesive and that the extended-closed and bent-closed conformations are nonadhesive. The functional effects and binding sites of antibodies and fibronectin were consistent with their ability in binding to alpha(5)beta(1) on cell surfaces to cross-enhance or inhibit one another by competitive or noncompetitive (allosteric) mechanisms.

Amyloidosis is a major problem in over one hundred diseases, including Alzheimer's disease (AD). Using the iDISCO visualization method involving targeted molecular labeling, tissue clearing, and light-sheet microscopy, we studied plaque formation in the intact AD mouse brain at up to 27 months of age. We visualized amyloid plaques in 3D together with tau, microglia, and vasculature. Volume imaging coupled to automated detection and mapping enables precise and fast quantification of plaques within the entire intact mouse brain. The present methodology is also applicable to analysis of frozen human brain samples without specialized preservation. Remarkably, amyloid plaques in human brain tissues showed greater 3D complexity and surprisingly large three-dimensional amyloid patterns, or TAPs. The ability to visualize amyloid in 3D, especially in the context of their micro-environment, and the discovery of large TAPs may have important scientific and medical implications.

Division of labor in insect societies relies on simple behavioral rules, whereby individual colony members respond to dynamic signals indicating the need for certain tasks to be performed. This in turn gives rise to colony-level phenotypes. However, empirical studies quantifying colony-level signal-response dynamics are lacking. Here, we make use of the unusual biology and experimental amenability of the queenless clonal raider ant Cerapachys biroi to jointly quantify the behavioral and physiological responses of workers to a social signal emitted by larvae. Using automated behavioral quantification and oocyte size measurements in colonies of different sizes and with different worker-to-larvae ratios, we show that the workers in a colony respond to larvae by increasing foraging activity and inhibiting ovarian activation in a progressive manner and that these responses are stronger in smaller colonies. This work adds to our knowledge of the processes that link plastic individual behavioral/physiological responses to colony-level phenotypes in social insect colonies.

Novel ideas are needed to increase adherence to antihypertensive medication. The current study used data from the Counseling African Americans to Control Hypertension (CAATCH) study, a sample of 442 hypertensive African Americans, to investigate the mediating effects of expectation of hypertension care, social support, hypertension knowledge, and medication adherence, adjusting for age, sex, number of medications, diabetes, education, income, employment, insurance status, and intervention. Sixty-six percent of patients had an income of $20,000 or less and 56% had a high school education or less, with a mean age of 57 years. Greater expectation of care was associated with greater medication adherence (P=.007), and greater social support was also associated with greater medication adherence (P=.046). Analysis also showed that expectation of care mediated the relationship between hypertension knowledge and medication adherence (P<.05). Expectation of care and social support are important factors for developing interventions to increase medication adherence among blacks.

Whole exome sequencing (WES) has proven an effective tool for the discovery of genetic defects in patients with primary immunodeficiencies (PIDs). However, success in dissecting the genetic etiology of common variable immunodeficiency (CVID) has been limited. We outline a practical framework for using WES to identify causative genetic defects in these subjects. WES was performed on 50 subjects diagnosed with CVID who had at least one of the following criteria: early onset, autoimmune/inflammatory manifestations, low B lymphocytes, and/or familial history of hypogammaglobulinemia. Following alignment and variant calling, exomes were screened for mutations in 269 PID-causing genes. Variants were filtered based on the mode of inheritance and reported frequency in the general population. Each variant was assessed by study of familial segregation and computational predictions of deleteriousness. Out of 433 variations in PID-associated genes, we identified 17 probable disease-causing mutations in 15 patients (30%). These variations were rare or private and included monoallelic mutations in NFKB1, STAT3, CTLA4, PIK3CD, and IKZF1, and biallelic mutations in LRBA and STXBP2. Forty-two other damaging variants were found but were not considered likely disease-causing based on the mode of inheritance and/or patient phenotype. WES combined with analysis of PID-associated genes is a cost-effective approach to identify disease-causing mutations in CVID patients with severe phenotypes and was successful in 30% of our cohort. As targeted therapeutics are becoming the mainstay of treatment for non-infectious manifestations in CVID, this approach will improve management of patients with more severe phenotypes.