Localization of specific antigens ofAzospirillum brasilense Cd in its exopolysaccharide by immuno-gold staining

Elicitation of specific antibodies towardsAzospirillum brasilense Cd was performed by injecting whole, living cells. The antigens which caused this specific response were detected by the immuno-gold technique and found to be located in the exopolysaccharide layer of the bacterial cells.     

Lysosomal cystine counter-transport in heterozygotes for cystinosis.

Heterozygotes for cystinosis exhibited approximately half the normal rate of cystine counter-transport into isolated leukocyte lysosomes. This gene-dosage effect strongly supports previous findings demonstrating that the basic defect in cystinosis is impaired cystine transport across the lysosomal membrane. The method was used to determine the cystinosis carrier status for siblings of affected children in two families with cystinosis.     

Prolonged Intracellular Na+ Dynamics Govern Electrical Activity in Accessory Olfactory Bulb Mitral Cells

Persistent activity has been reported in many brain areas and is hypothesized to mediate working memory and emotional brain states and to rely upon network or biophysical feedback. Here, we demonstrate a novel mechanism by which persistent neuronal activity can be generated without feedback, relying instead on the slow removal of Na⁺ from neurons following bursts of activity. We show that mitral cells in the accessory olfactory bulb (AOB), which plays a major role in mammalian social behavior, may respond to a brief sensory stimulation with persistent firing. By combining electrical recordings, Ca²⁺ and Na⁺ imaging, and realistic computational modeling, we explored the mechanisms underlying the persistent activity in AOB mitral cells. We found that the exceptionally slow inward current that underlies this activity is governed by prolonged dynamics of intracellular Na⁺ ([Na⁺]_i), which affects neuronal electrical activity via several pathways. Specifically, elevated dendritic [Na⁺]_i reverses the Na⁺-Ca²⁺ exchanger activity, thus modifying the [Ca²⁺]_i set-point. This process, which relies on ubiquitous membrane mechanisms, is likely to play a role in other neuronal types in various brain regions.     

Avidin-biotin complex incorporation into enzyme-linked immunosorbent assay (ABELISA) for improving the detection ofAzospirillum brasilense Cd

The purpose of this study was to ascertain whether an assay for bacterial lipopolysaccharide (LPS) could be developed based on the specific, stoichiometric binding between Polymyxin B and lipopolysaccharides. Polymyxin B was covalently linked to Sepharose 4B and the LPS-binding capacity of the resulting gel determined by incubation with various amounts of radiolabeled LPS (¹⁴C-LPS) of known specific activity. Competitive binding studies showed an inverse linear relationship between the amount of unlabeled LPS added and the binding of¹⁴C-LPS. The assay enabled the detection of microgram quantities of LPS even though the specific activity of the¹⁴C-LPS used was very low. The study demonstrated the feasibility of a Polymyxin B-based assay for LPS, and possible ways in which the sensitivity of the assay may be increased are discussed.     

Survival of Azospirillum brasilense in the Bulk Soil and Rhizosphere of 23 Soil Types

The survival of Azospirillum brasilense Cd and Sp-245 in the rhizosphere of wheat and tomato plants and in 23 types of plant-free sterilized soils obtained from a wide range of environments in Israel and Mexico was evaluated. Large numbers of A. brasilense cells were detected in all the rhizospheres tested, regardless of soil type, bacterial strain, the origin of the soil, or the amount of rainfall each soil type received prior to sampling. Survival of A. brasilense in soils without plants differed from that in the rhizosphere and was mainly related to the geographical origin of the soil. In Israeli soils from arid, semiarid, or mountain regions, viability of A. brasilense rapidly declined or populations completely disappeared below detectable levels within 35 days after inoculation. In contrast, populations in the arid soils of Baja California Sur, Mexico, remained stable or even increased during the 45-day period after inoculation. In soils from Central Mexico, viability slowly decreased with time. In all soils, percentages of clay, nitrogen, organic matter, and water-holding capacity were positively correlated with bacterial viability. High percentages of CaCO(inf3) and fine or rough sand had a highly negative effect on viability. The percentage of silt, pH, the percentage of phosphorus or potassium, electrical conductivity, and C/N ratio had no apparent effect on bacterial viability in the soil. Fifteen days after removal of inoculated plants, the remaining bacterial population in the three soil types tested began to decline sharply, reaching undetectable levels 90 days after inoculation. After plant removal, percolating the soils with water almost eliminated the A. brasilense population. Viability of A. brasilense in two artificial soils containing the same major soil components as the natural soils from Israel did was almost identical to that in the natural soils. We conclude that A. brasilense is a rhizosphere colonizer which survives poorly in most soils for prolonged periods of time; that outside the rhizosphere, seven abiotic parameters control the survival of this bacterium in the soil; and that disturbance of the soil (percolation with water or plant removal) directly and rapidly affects the population levels.     

Flash Glucose Monitoring in Israel: Understanding Real-World Associations between Self-Monitoring Frequency and Metrics of Glycemic Control

ObjectiveFlash glucose monitoring has been widely used in Israel for diabetes treatment and since 2018, the cost is reimbursed for all people with type 1 diabetes nationally. In the current study, we present the daily scanning behavior for FreeStyle Libre users in Israel and how this was associated with a range of metrics for glycemic assessment.MethodsDeidentified data from FreeStyle Libre readers were collected between September 2014 and October 2020. Scan-rate data from Israel was extracted and sorted into 10 equal-sized groups based on scan frequency. The glucose parameters derived for each group were: estimated HbA1c (eA1c), time in range (TIR) between 70 and 180 mg/dL, and time with glucose levels of <70 mg/dL, <54 mg/dL, and >180 mg/dL.ResultsThe data set for Israel included 12 370 readers, with data from 131 639 separate glucose sensors representing 152 million automatically recorded individual glucose readings. Users performed an average of 15 daily glucose scans, ranging from a mean of 4.1 scans per day (lowest, 10%), rising to a mean of 38.7 scans/day (highest, 10%) (median, 12; IQR, 8-18 for all readers). As the scan rates increased, the eA1c decreased from 7.6% to 6.7% (P < .001). Mean TIR increased from 56.9% to 70.0% with increasing scan rates (P < .001). Concordantly, time with glucose levels of >180 mg/dL and <54 mg/dL decreased from 37.2% to 23.6% (P < .001) and from 2.23% to 1.99%, respectively, as scan frequency increased.ConclusionIn Israel, people with diabetes under real-world conditions record higher rates of FreeStyle Libre scanning. These are associated with improvements in TIR, eA1c, and reduced time with glucose levels of >180 mg/dL or <54 mg/dL.     

Tight junction proteins expression and modulation in immune cells and multiple sclerosis

The tight junction proteins (TJPs) are major determinants of endothelial cells comprising physiological vascular barriers such as the blood–brain barrier, but little is known about their expression and role in immune cells. In this study we assessed TJP expression in human leukocyte subsets, their induction by immune activation and modulation associated with autoimmune disease states and therapies. A consistent expression of TJP complexes was detected in peripheral blood leukocytes (PBLs), predominantly in B and T lymphocytes and monocytes, whereas the in vitro application of various immune cell activators led to an increase of claudin 1 levels, yet not of claudin 5. Claudins 1 and 5 levels were elevated in PBLs of multiple sclerosis (MS) patients in relapse, relative to patients in remission, healthy controls and patients with other neurological disorders. Interestingly, claudin 1 protein levels were elevated also in PBLs of patients with type 1 diabetes (T1D). Following glucocorticoid treatment of MS patients in relapse, RNA levels of JAM3 and CLDN5 and claudin 5 protein levels in PBLs decreased. Furthermore, a correlation between CLDN5 pre‐treatment levels and clinical response phenotype to interferon‐β therapy was detected. Our findings indicate that higher levels of leukocyte claudins are associated with immune activation and specifically, increased levels of claudin 5 are associated with MS disease activity. This study highlights a potential role of leukocyte TJPs in physiological states, and autoimmunity and suggests they should be further evaluated as biomarkers for aberrant immune activity and response to therapy in immune‐mediated diseases such as MS.