Neutralization of the anthrax toxin by antibody-mediated stapling of its membrane-penetrating loop.

Anthrax infection is associated with severe illness and high mortality. Protective antigen (PA) is the central component of the anthrax toxin, which is one of two major virulence factors of Bacillus anthracis, the causative agent of anthrax disease. Upon endocytosis, PA opens a pore in the membranes of endosomes, through which the cytotoxic enzymes of the toxin are extruded. The PA pore is formed by a cooperative conformational change in which the membrane-penetrating loops of PA associate, forming a hydrophobic rim that pierces the membrane. Due to its crucial role in anthrax progression, PA is an important target for monoclonal antibody-based therapy. cAb29 is a highly effective neutralizing antibody against PA. Here, the cryo-EM structure of PA in complex with the Fab portion of cAb29 was determined. It was found that cAb29 neutralizes the toxin by clamping the membrane-penetrating loop of PA to the static surface-exposed loop of the D3 domain of the same subunit, thereby preventing pore formation. These results provide the structural basis for the antibody-based neutralization of PA and bring into focus the membrane-penetrating loop of PA as a target for the development of better anti-anthrax vaccines.

Near-equilibrium isotope fractionation during planetesimal evaporation.

Silicon and Mg in differentiated rocky bodies exhibit heavy isotope enrichments that have been attributed to evaporation of partially or entirely molten planetesimals. We evaluate the mechanisms of planetesimal evaporation in the early solar system and the conditions that controled attendant isotope fractionations. Energy balance at the surface of a body accreted within ~1 Myr of CAI formation and heated from within by 26Al decay results in internal temperatures exceeding the silicate solidus, producing a transient magma ocean with a thin surface boundary layer of order < 1 meter that would be subject to foundering. Bodies that are massive enough to form magma oceans by radioisotope decay (≥ 0.1% M ⊕) can retain hot rock vapor even in the absence of ambient nebular gas. We find that a steady-state rock vapor forms within minutes to hours and results from a balance between rates of magma evaporation and atmospheric escape. Vapor pressure buildup adjacent to the surfaces of the evaporating magmas would have inevitably led to an approach to equilibrium isotope partitioning between the vapor phase and the silicate melt. Numerical simulations of this near-equilibrium evaporation process for a body with a radius of ~ 700 km yield a steady-state far-field vapor pressure of 10-8 bar and a vapor pressure at the surface of 10-4 bar, corresponding to 95% saturation. Approaches to equilibrium isotope fractionation between vapor and melt should have been the norm during planet formation due to the formation of steady-state rock vapor atmospheres and/or the presence of protostellar gas. We model the Si and Mg isotopic composition of bulk Earth as a consequence of accretion of planetesimals that evaporated subject to the conditions described above. The results show that the best fit to bulk Earth is for a carbonaceous chondrite-like source material with about 12% loss of Mg and 15% loss of Si resulting from near-equilibrium evaporation into the solar protostellar disk of H2 on timescales of 104 to 105 years.

Dual energy CT for evaluation of polycystic kidneys: a multi reader study of interpretation time and diagnostic confidence.

PURPOSE: To compare dual-energy CT (DECT) iodine overlay images with renal mass protocol CT in the evaluation of polycystic kidneys with respect to reading time, diagnostic confidence, and detection of renal lesions that are not definitively benign. METHODS: Following IRB approval, portal venous phase dual-source DECT scans performed between September 2013 and February 2016 from 55 patients (mean age 67 ± 15 years, 31 male, 24 female) with polycystic kidneys (4 or more cysts) were included. For each patient, two image sets were created: (1) DECT post-processed iodine overlay images and (2) simulated renal mass protocol CT images (virtual noncontrast and mixed images). Two radiologists independently retrospectively reviewed both sets at separate time points, evaluating for the presence of lesions that were not definitively benign (enhancing lesions or Bosniak IIF cysts), as well as reading times and Likert scale diagnostic confidence ratings (scaled 1-5) for the presence of non-benign lesions. Reading times were compared with a t test, diagnostic confidence with a McNemar test, and lesion number detection with Cohen's kappa test. RESULTS: Iodine overlay images were read faster (mean 55 ± 26 s) than renal mass protocol (mean 105 ± 51 s) (p < 0.001). Readers assigned the highest diagnostic confidence rating in 64% using iodine overlay series, compared to 17% using renal mass protocol (p < 0.0001). The proportion of patients with recorded lesions was not significantly different between methods (p = 0.62). CONCLUSIONS: DECT improves lesion assessment in polycystic kidneys by decreasing reading times and increasing diagnostic confidence, without affecting lesion detection rates.

Acute Nonhemorrhagic Adrenal Infarction in Pregnancy: 10-Year MRI Incidence and Patient Outcomes at a Single Institution.

OBJECTIVE: The purpose of this study was to retrospectively investigate the MRI incidence of nonhemorrhagic adrenal infarction in pregnant women undergoing MRI evaluation of acute abdominal or flank pain, assess the MRI features quantitatively, and report patient outcomes. MATERIALS AND METHODS: All abdominal MRI examinations of pregnant women with acute pain at one institution from May 2005 to April 2015 were reviewed. The adrenals were evaluated for abnormal morphologic and signal intensity characteristics described in the literature characterizing nonhemorrhagic adrenal infarction and were compared with the contralateral adrenal by paired t tests. The findings were correlated with clinical presentation. Patient demographics and outcomes were gathered from the medical record. RESULTS: Findings of nonhemorrhagic adrenal infarction were present in 5 of 379 (1.3%) examinations of four pregnant patients (mean age, 28 years; range, 20.8-33.9 years; mean gestational age, 26 weeks; range, 16-35 weeks). MRI features included lengthening (mean, 39.8 versus 21.2 mm) (p = 0.005) and increased T2 signal intensity (p = 0.001) of the infarcted adrenal with surrounding edema and without T1 signal intensity suggesting hemorrhage. No alternative diagnosis was identified. All patients presented with severe acute abdominal or flank pain on the same side as the MRI findings, tenderness to palpation, and mild leukocytosis. All women delivered healthy infants. CONCLUSION: Unilateral nonhemorrhagic adrenal infarction was identified in 1.3% of abdominal MRI examinations performed for pregnant women with acute abdominal or flank pain. Knowledge of the MRI characteristics of this entity is important for recognizing it and may prevent further potentially invasive tests, procedures, or missed diagnoses.

Influence of Different ECM-Like Hydrogels on Neurite Outgrowth Induced by Adipose Tissue-Derived Stem Cells.

Mesenchymal stem cells (MSCs) have been proposed for spinal cord injury (SCI) applications due to their capacity to secrete growth factors and vesicles-secretome-that impacts important phenomena in SCI regeneration. To improve MSC survival into SCI sites, hydrogels have been used as transplantation vehicles. Herein, we hypothesized if different hydrogels could interact differently with adipose tissue-derived MSCs (ASCs). The efficacy of three natural hydrogels, gellan gum (functionalized with a fibronectin peptide), collagen, and a hydrogel rich in laminin epitopes (NVR-gel) in promoting neuritogenesis (alone and cocultured with ASCs), was evaluated in the present study. Their impact on ASC survival, metabolic activity, and gene expression was also evaluated. Our results indicated that all hydrogels supported ASC survival and viability, being this more evident for the functionalized GG hydrogels. Moreover, the presence of different ECM-derived biological cues within the hydrogels appears to differently affect the mRNA levels of growth factors involved in neuronal survival, differentiation, and axonal outgrowth. All the hydrogel-based systems supported axonal growth mediated by ASCs, but this effect was more robust in functionalized GG. The data herein presented highlights the importance of biological cues within hydrogel-based biomaterials as possible modulators of ASC secretome and its effects for SCI applications.

Pressure-dependent isotopic composition of iron alloys.

Our current understanding of Earth's core formation is limited by the fact that this profound event is far removed from us physically and temporally. The composition of the iron metal in the core was a result of the conditions of its formation, which has important implications for our planet's geochemical evolution and physical history. We present experimental and theoretical evidence for the effect of pressure on iron isotopic composition, which we found to vary according to the alloy tested (FeO, FeH(x), or Fe3C versus pure Fe). These results suggest that hydrogen or carbon is not the major light-element component in the core. The pressure dependence of iron isotopic composition provides an independent constraint on Earth's core composition.

Development of a tissue-engineered composite implant for treating traumatic paraplegia in rats.

This study was designed to assess a new composite implant to induce regeneration of injured spinal cord in paraplegic rats following complete cord transection. Neuronal xenogeneic cells from biopsies of adult nasal olfactory mucosa (NOM) of human origin, or spinal cords of human embryos, were cultured in two consecutive stages: stationary cultures in a viscous semi-solid gel (NVR-N-Gel) and in suspension on positively charged microcarriers (MCs). A tissue-engineered tubular scaffold, containing bundles of parallel nanofibers, was developed. Both the tube and the nanofibers were made of a biodegradable dextran sulphate-gelatin co-precipitate. The suturable scaffold anchored the implant at the site of injury and provided guidance for the regenerating axons. Implants of adult human NOM cells were implanted into eight rats, from which a 4 mm segment of the spinal cord had been completely removed. Another four rats whose spinal cords had also been transected were implanted with a composite implant of cultured human embryonic spinal cord cells. Eight other cord-transected rats served as a control group. Physiological and behavioral analysis, performed 3 months after implantation, revealed partial recovery of function in one or two limbs in three out of eight animals of the NOM implanted group and in all the four rats that were implanted with cultured human embryonic spinal cord cells. Animals of the control group remained completely paralyzed and did not show transmission of stimuli to the brain. The utilization of an innovative composite implant to bridge a gap resulting from the transection and removal of a 4 mm spinal cord segment shows promise, suggesting the feasibility of this approach for partial reconstruction of spinal cord lesions. Such an implant may serve as a vital bridging station in acute and chronic cases of paraplegia.

Seasonal variations in dietary intake affect the consistency of dietary assessment.

BACKGROUND: Nutritional epidemiology studies are usually based on one dietary assessment without taking into account the season in which the interview is taken or adjusting for the difference in reporting dietary intake in different seasons. The semiquantitative food frequency questionnaire has become the primary questionnaire method for measuring dietary intake in epidemiological studies. The aims of this report were (a) to evaluate the effect of season on dietary intake as measured by a semiquantitative food frequency questionnaire (FFQ) conducted twice: once in summer and a second time in winter; and (b) to assess the effect of the differences in dietary intake on biochemical and anthropometric seasonal related changes, such as serum cholesterol and body mass index (BMI). POPULATION AND METHODS: The study population consisted of 94 male industrial employees who participated in clinical biochemical and physical examinations as well as evaluation of their dietary intake twice a year. Dietary intake was assessed using the semiquantitative FFQ that included 96 items and was conducted by a personal interview. RESULTS: We found a significant increase in the intake of selected nutrients in winter as compared to summer as well as an increased intake of animal fat-containing foods such as meat and dairy products. Significant correlation coefficients were shown between the increase in dietary intake of saturated fat and the increase in BMI, serum total and LDL cholesterol. The increase in dietary cholesterol was significantly and positively correlated with the increase in serum total and LDL cholesterol. CONCLUSION: Although FFQ are designed to assess average yearly food intake, we identified significant seasonal changes in dietary intake as measured by FFQ. These changes have a health impact on our population.

High prevalence and impact of subnormal serum vitamin B12 levels in Israeli elders admitted to a geriatric hospital.

BACKGROUND: The elderly are known to have higher rates of low and subnormal vitamin B12 levels than younger persons. Vitamin B12 deficiency has been extensively studied in the elderly, but primarily in outpatient settings. There is a paucity of data regarding the prevalence of low and low-normal B12 in frail, hospitalized, elderly patients, and its implications. Additionally, there is little information regarding vitamin B12 status in Israeli elders. OBJECTIVES: The objectives of the study were to estimate the prevalence of low and borderline vitamin B12 levels among frail, hospitalized, elderly patients, and their clinical implications. METHODS: We conducted a chart review, using a retrospective cohort design. The participants were 895 patients admitted to Harzfeld Medical Center in Gedera, Israel. Records were abstracted for vitamin B12 and Folic Acid levels, gastric disease, and outcomes including death, cognitive impairment and neurologic disease. RESULTS: Six hundred and forty patients were eligible for the study. In 15% of the patients, vitamin B12 level was in the low range (<150pmol/L) and in 25% in the low-normal range (150-250pmol/L). Gastric disease and antacid use were not associated with the vitamin B12 status. Mortality was higher in the high vitamin B12 group (p=0.02), perhaps reflecting a selection toward higher acuity in this group. Cerebrovascular disease was more common in patients with lower vitamin B12 levels (p=0.046). CONCLUSIONS: Forty percent of hospitalized elderly patients have low or borderline serum levels of vitamin B12, which may contribute to cerebrovascular disease and cognitive decline.

The effect of widowhood on weight change, dietary intake, and eating behavior in the elderly population.

OBJECTIVES: To assess the effect of recent widowhood on weight, dietary intake, and habits. METHODS: Participants included 58 recently widowed elderly subjects and 58 married subjects who were matched on age, sex, and race. Weight change from baseline and following widowhood, dietary intake, eating behavior, depression, and cognitive and physical functioning were assessed in a clinic interview. RESULTS: Mean weight loss and the prevalence of weight loss were significantly higher among widowed participants. They ate more meals alone, more commercial meals per week, and fewer snacks and homemade meals. They also enjoyed their eating less. A significant difference between cases and controls was evident after adjusting for all the variables. Higher cognitive functioning score, younger age, and better appetite were protective against weight loss. DISCUSSION: Widowed people were found to be at increased risk for weight loss. This may well be due to decreased appetite and enjoyment of their meals.

An international training program to assist with establishing emergency medicine in Ethiopia.

Ethiopia has a population of 56 million and an area of 1,110,000 km(2). Ethiopia is one of the poorest nations in the world, and its health services system reflects that poverty. Accidental injury, violence, infectious diseases, and natural and manmade disasters abound, yet emergency medicine is practically nonexistent. Poorly equipped and staff emergency "rooms" supply substandard service even in the capital. Significant work and planning are under way by a group of high-quality and dedicated local physicians and nurses with international support from Israel and the United States. A coherent plan is due at the end of the year. Much financial and professional support from outside sources will be required for significant advances in the quality of emergency care to improve. Human as well are material resources are vital.

[Hospitalization for renal colic in the emergency room of a large central hospital in Israel: epidemiological features and clinical manifestations].

The medical records of all patients referred to the emergency department (ED) of Sheba Medical Center for renal colic during 1996 were analyzed. Patients discharged from the ED and those hospitalized were compared. There was no significant difference between the 2 groups with regard to average age or sex distribution. Statistically significant differences were found with regard to frequency of chills and fever, history of renal colic, referral for renal colic during that year or hospitalization for renal colic or nephrolithiasis, previous positive imaging, stone removal by surgery or extracorporeal shock wave lithotripsy, fever exceeding 37.5 degrees and administration of fluids, pethidine or pramin in the ED, prolonged stay in the ED and previous appendectomy. A conditional regression model tested the predictive value of each of those factors. Inclusion of independent variables into the model led to an overall correct classification rate of 84.43%, with 44.83% sensitivity and 93.16% specificity. There were correlations between referrals for renal colic, overall renal colic rate and average monthly temperature, so there was no pure correlation between average monthly temperature and referrals to the ED for renal colic. The major indications for hospitalization were actually the clinical ones, indicating either an active metabolic disease or suspected obstruction of the urinary tract. Treatment in the ED and duration of the visit indicated disease severity.

Patients with stages III and IV endometriosis have a poorer outcome of in vitro fertilization-embryo transfer than patients with tubal infertility.

OBJECTIVE: To evaluate the outcome of IVF in patients with stages III and IV endometriosis. DESIGN: Retrospective study. SETTING: The Sara Racine IVF Unit, Lis Maternity Hospital, Tel Aviv Sourasky Medical Center, Israel. PATIENT(S): Fifty-eight patients with stages III and IV endometriosis and 60 patients with tubal infertility. INTERVENTION(S): IVF-ET for all couples. MAIN OUTCOME MEASURE(S): Fertilization, pregnancy, and birth rates. RESULT(S): The comparison between patients with endometriosis and those with tubal infertility indicated that the former had a poor IVF outcome in terms of reduced fertilization rate (40% vs. 70%), reduced pregnancy rate per cycle (10.6% vs. 22.4%), and reduced birth rate per cycle (6.7% vs. 16.6%). The differences were statistically significant. CONCLUSION(S): The results show an unfavorable outcome of IVF-ET in patients with endometriosis when compared with those who have tubal infertility.

A single nucleotide change in the 5' noncoding region of Sindbis virus confers neurovirulence in rats.

Two pairs of Sindbis virus (SV) variants that differ in their neuroinvasive and neurovirulent traits in mice have been isolated. Recently, we mapped the genetic determinants responsible for neuroinvasiveness in weanling mice. Here, we extend this study to newborn and adult rats and to rat neuronal cultures. Remarkably, certain aspects of the pathogenesis of these strains in rats were found to be quite distinct from the mouse model. Suckling rats were susceptible to all four isolates, and replication in the brain was observed after both intraperitoneal and intracranial (i.c.) inoculation. None of the isolates was neuroinvasive in adult rats, although all replicated after i.c. inoculation. For the isolate pair that was highly neurovirulent in mice, SVN and SVNI, only SVNI caused death after i.c. inoculation of adult rats. Similarly, only SVNI was cytotoxic for primary cultures of mature neurons. The genetic determinants responsible for the pathogenic properties of SVNI were mapped to the E2 glycoprotein and the 5' noncoding region (5'NCR). Substitution of two amino acids in SVN E2 with the corresponding residues of SVNI (Met-190 and Lys-260) led to paralysis in 3- and 5-week-old rats. More dramatically, a single substitution in the 5'NCR of SVN (G at position 8) transformed the virus into a lethal pathogen for 3-week-old rats like SVNI. In 5-week-old rats, however, this recombinant was attenuated relative to SVNI by 2 orders of magnitude. Combination of the E2 and 5'NCR determinants resulted in a recombinant with virulence properties indistinguishable from those of SVNI. These data indicate that the 5'NCR and E2 play an instrumental role in determining the age-dependent pathogenic properties of SV in rats.

Endothelial trophic support of neuronal production and recruitment from the adult mammalian subependyma.

Vascular endothelial cells are among the first cells that ventricular zone neuroblasts encounter during early development. The ventricular zone cells promote angiogenesis by the invading vasculature, with the release of endothelial mitogens. Yet the feedback support of young neurons by endothelial cells (ECs) has not hitherto been explored. We therefore asked whether ECs might participate in neuronal recruitment, by providing neurotrophic support to newly generated neurons. We used the neurogenic subependymal zone (SZ) of the adult rat forebrain as a model system, because of its well-characterized and relatively homogeneous population of neuronal precursor cells. We found that explants of the adult rat SZ raised on ECs generated more neurons, which survived longer, than explants raised on astrocytes, fibroblasts, or laminin. This endothelial trophic effect was humoral, in that it was also noted in SZ explants raised in noncontiguous coculture with ECs grown on porous inserts. RT-PCR for neurotrophin family members revealed that cultures of both human brain- and umbilical cord-derived ECs produced brain-derived neurotrophic factor (BDNF) mRNA, but no detectable NGF, NT-3, or NT-4 mRNA. ELISA revealed that BDNF protein was secreted by ECs into the medium at >1 ng/ml. The neurotrophic effect of ECs could be replaced by added BDNF, and was blocked by addition of 5 microg/ml trkB-Fc to endothelial-SZ cocultures. Thus, endothelial cells can act as sources of secreted BDNF, through which the capillary microvasculature may act to support neuronal recruitment and survival in the CNS.

Survival without surgical repair of acute rupture of the right ventricular free wall.

Rupture of the myocardial free wall is an infrequent complication of acute myocardial infarction. Unless it occurs in a space confined by pericardial adhesions, only surgical emergency repair of ruptured myocardium can prevent death. In this paper we report the case of an 81-year-old woman who was admitted to the emergency room with cardiac tamponade, resulting from inferolateral acute myocardial infarction and a subsequent rupture of the right ventricular free wall, with the formation of pericardial thrombus and effusion. The patient refused to undergo any surgical or invasive intervention, and therefore she was only treated conservatively. Nevertheless, her condition improved dramatically, as her blood pressure increased and echocardiography abnormalities almost disappeared. Follow-up echocardiography 7 months post discharge was unremarkable. We believe that this rare case emphasizes that in special circumstances, such as creation of a thrombus that prevents more blood from extravasating, free-wall rupture without surgical repair is compatible with long-term survival.

CEBQ: Composite Eating Behavior Questionnaire--development and performance.

Poor eating behavior is an important nutritional risk factor among community dwelling elders, and precedes overt malnutrition in the majority of cases. Several tools were developed to assess nutritional risk through evaluating eating behavior. All containing elements shown to be related to nutritional decline. Given the diversity of the geriatric population each tool may apply to specific subsets of the population but not to all. The ideal tool may be a questionnaire tailored for the study population based on a pool of methods and questions. We describe the development and use of such a composite tool, and compares its performance to other questionnaires. Our results show that in community dwelling elders nutrition risk assessments such as the NRI or eating behavior score were not predictive of nutritional status measured by dietary intake, weight change or BMI. Subjective appetite assessment was the most predictive question for nutritional decline. We describe the questionnaire and its development and offer general advice to its future implementations.