Separation of bovine X and Y sperm based on surface differences

Aqueous two-phase partition involving thin-layer counter current distribution (TLCCD) has been used to assess surface heterogeneity of ejaculated bovine sperm. When partitioned in charge-insensitive aqueous two-phase systems, which detect non-charge associated surface properties, the sperm fractionates into two distinct populations. Using a Y-chromosome-specific DNA marker, it has been shown that one of these populations is enriched in Y chromosome bearing sperm. However, this population is not pure—it consists of 80% Y sperm, with the other 20% being X sperm. All the sperm in the original population that had begun to undergo the acrosome reaction were separated into this same peak; the sex chromosome composition of these sperm is unknown. Since the aqueous partition of sperm is based on surface properties these results suggest that two populations of Y sperm exist that have different surface characteristics. © 1993 Wiley-Liss, Inc.     

Bone Embedding Technique with Inhibited Pmma Monomer

Unwashed inhibited thin and thick methyl methacrylate monomer was used for successful embedding of bone by increasing the quantity of benzoyl peroxide catalyst until the activity of the hydroquihone inhibitor was overwhelmed. Seven bones were embedded using 1, 2, 4, 6, 8, 10 or 12 grams of benzoyl peroxide per 100 milliliters of thick monomer. Two grams per 100 ml was found to be optimal. Higher concentrations resulted in uncontrolled polymerization while at 1 g/100 ml the solution remained liquid.     

Genetic damage induced by an occupational complex and prolonged chemical exposure

Some results of a study on the clastogenicity of chemicals in vivo are reported. The chromosomes in lymphocytes from whole blood cultures were studied in 60 subjects permanently exposed for about 6 years to several occupational chemicals acting concomitantly, and in 5 controls. The exposed subjects showed an increase in the rate of chromosomal aberrations as compared to controls.     

Carbon, Water, and Energy Exchanges of a Hybrid Poplar Plantation During the First Five Years Following Planting

Eddy covariance was used to measure above-canopy exchanges of CO₂ and water vapor at an operational plantation of hybrid poplar (variety ??Walker??) established on marginal agricultural land in east central Alberta, Canada. Winter ecosystem respiration (R _e) rates were inferred from seasonal changes in the normalized respiration rate at 10°C (R ₁₀) for the growing season and observations of soil CO₂ concentration measured with solid-state probes. Over five consecutive growing seasons following planting, gross ecosystem production (GEP) increased each year, ranging from 21?g?C?m^?2?y^?1 in year 1 to 469?g?C?m^?2?y^?1 in year 5. During this period, the annual carbon balance shifted from a net source of greater than 330?g?C?m^?2 in year 1 to approximately C-neutral in year 5. Total carbon (C) release over 5?years likely exceeded 630?g?C?m^?2. Intra- and interannual variations in temperature and soil water availability greatly affected annual C balance each year. GEP and R _e were particularly sensitive to temperature during spring and to soil water availability in summer: year 5 was notable because a cold spring and accumulating drought caused growth and carbon uptake to fall well below their potential. Annual evapotranspiration (ET) increased slightly with leaf area, from 281?mm in year 1 to 323?mm in year 4, but in year 5 it declined, while exceeding total precipitation (P). This trend of increasing annual ET/P suggests that annual GEP could become increasingly water-limited in years with below normal precipitation, as the plantation achieves maximum leaf area. Measured canopy albedos did not change appreciably over three winters, suggesting that estimates of increased radiative forcing resulting from afforestation in high latitudes could be exaggerated in regions where fast-growing deciduous plantations are managed on short (~20-year) rotations.     

Prevalence and Characteristics of Hyperthyroidism Among Patients With Sarcoidosis in the United States

ObjectiveWe aimed to determine the prevalence and clinical characteristics of self-reported hyperthyroidism in patients with sarcoidosis.MethodsA national registry-based study investigating 3836 respondents to the Sarcoidosis Advanced Registry for Cures questionnaire in the period between June 2014 and August 2019 was conducted. This registry is generated from a web-based questionnaire that is self-reported by patients with sarcoidosis. We compared patients with sarcoidosis who had hyperthyroidism with those who did not. We used multivariate logistic regression analysis to study the association between hyperthyroidism and different cardiac manifestations in patients with sarcoidosis.ResultsThree percent of the study respondents self-reported having hyperthyroidism and were generally middle-aged Caucasian women. Compared with patients without hyperthyroidism, patients with hyperthyroidism had more sarcoidosis-related comorbidities (59% vs 43%, P = .001) and more steroid-related comorbidities (56% vs 44%, P = .01), but there was no difference in the sarcoidosis-specific treatments they received, which included corticosteroids. Patients with hyperthyroidism reported sarcoidosis involvement of the heart (26.6% vs 14.9%, P = .005), kidneys (14.9% vs 8%, P = .033) and sinuses (17.7% vs 10.2%, P = .030) more frequently. Cardiac manifestations that were more frequently reported in patients with hyperthyroidism included atrial arrhythmias (11.3% vs 6.3%, P = .046), ventricular arrhythmias (17.2% vs 7.5%, P < .001), congestive heart failure (10.4% vs 5%, P = .017), and heart block (9.4% vs 4.7%, P = .036).ConclusionHyperthyroidism is infrequent in patients with sarcoidosis but is potentially associated with different cardiac manifestations. We suggest considering routine screening for hyperthyroidism in patients with sarcoidosis, especially in those with cardiac involvement. Further studies are needed to investigate the impact of identifying and treating hyperthyroidism in patients with sarcoidosis.     

Isolated rabbit enterocytes as a model cell system for investigations of chylomicron assembly and secretion.

A method is described for the isolation of viable enterocytes from rabbit small intestine. The procedure can also be used to isolate populations of epithelial cells from the crypt/villus gradient. The isolated enterocytes synthesized and secreted apoB-48 and triacylglycerol in particles of the density of chylomicrons. Secretion was stimulated by addition of bile salt/lipid micelles. Pulse-chase experiments demonstrated that newly synthesized apoB-48 is degraded intracellularly and that degradation is inhibited by provision of lipid micelles, suggesting that regulation of chylomicron assembly and secretion is broadly similar to that of very low density lipoprotein assembly in hepatocytes. This procedure for preparation of isolated enterocytes will provide a useful model system for investigation of the molecular details of chylomicron assembly.