Mechanism of slowing of mucociliary transport induced by SO2 exposure

Responses of nasal mucociliary transport mechanisms to exposure to 6 ppm SO₂ were studied in chickens in vivo. This model takes advantage of the natural cleft palate which exposes the mucociliated base of the nasal septum. Exposure to 6 ppm SO₂ decreased the mucociliary transport rate along the base of the nasal septum. The minimum force required to move an iron particle along this area of mucous membrane by use of a magnetic field in vivo increased significantly after SO₂ exposure, while the minimum force required to move an iron particle on a pool of mucus collected from the same chicken and tested in vitro showed no change after SO₂ exposure. The elastic recoil distance of mucus was measured both in vivo and in vitro. The in vivo recoil distance decreased significantly after SO₂ exposure, while SO₂ exposure did not change recoil distance in vitro. It is proposed that exposure of chickens to SO₂ results in the formation of multiple points of adhesion of strands of mucus between the acinar gland cells and the emergent extracellular mucus or adhesion of a mucous blanket to the cilia, causing mucociliary transport to be retarded or static.     

Lymphocyte Depression Induced in Chickens on Diets Deficient in Vitamin A and Other Components

Chloroma (chloroleukemia) was induced in a splenectomized rat by repeatedly administering dimethylbenz(a)anthracene (DMBA) and was serially transplanted thereafter. Composed of immature myeloid cells, the tumor imparted a green discoloration to the tissues that it infiltrated extensively. Chloroma cells fluoresced red in ultraviolet light, produced a characteristic curve in spectrophotometry, and contained large amounts of myeloperoxidase. They included numerous intracytoplasmic granules of both types A and B, which contained occasional crystalline bars. Permanent lines of chloroma cells were established in tissue culture. These cells, while maintaining their initial morphology, ceased producing myeloperoxidase and subsequently induced white tumors when they were isotransplanted.     

Evaluating Differences in Whole Blood,Serum, and Urine Screening Tests for Zika Virus,Puerto Rico,USA, 2016

We evaluated nucleic acid amplification testing (NAAT) for Zika virus on whole-blood specimens compared with NAAT on serum and urine specimens among asymptomatic pregnant women during the 2015–2016 Puerto Rico Zika outbreak. Using NAAT, more infections were detected in serum and urine than in whole blood specimens.     

Novel 6-Month Treatment for Drug-Resistant Tuberculosis,United States

The US Food and Drug Administration approved a 6-month regimen of pretomanid, bedaquiline, and linezolid for extensively drug-resistant or multidrug-intolerant tuberculosis after a trial in South Africa demonstrated 90% effectiveness 6 months posttreatment. We report on a patient who completed the regimen using a lower linezolid dose.     

Components of the Gut Microbiome That Influence Bone Tissue-Level Strength

Modifications to the constituents of the gut microbiome influence bone density and tissue-level strength, but the specific microbial components that influence tissue-level strength in bone are not known. Here, we selectively modify constituents of the gut microbiota using narrow-spectrum antibiotics to identify components of the microbiome associated with changes in bone mechanical and material properties. Male C57BL/6J mice (4 weeks) were divided into seven groups (n = 7–10/group) and had taxa within the gut microbiome removed through dosing with: (i) ampicillin; (ii) neomycin; (iii) vancomycin; (iv) metronidazole; (v) a cocktail of all four antibiotics together (with zero-calorie sweetener to ensure intake); (vi) zero-calorie sweetener only; or (vii) no additive (untreated) for 12 weeks. Individual antibiotics remove only some taxa from the gut, while the cocktail of all four removes almost all microbes. After accounting for differences in geometry, whole bone strength was reduced in animals with gut microbiome modified by neomycin (−28%, p = 0.002) and was increased in the group in which the gut microbiome was altered by sweetener alone (+39%, p < 0.001). Analysis of the fecal microbiota detected seven lower-ranked taxa differentially abundant in animals with impaired tissue-level strength and 14 differentially abundant taxa associated with increased tissue-level strength. Histological and serum markers of bone turnover and trabecular bone volume per tissue volume (BV/TV) did not differ among groups. These findings demonstrate that modifications to the taxonomic components of the gut microbiome have the potential to decrease or increase tissue-level strength of bone independent of bone quantity and without noticeable changes in bone turnover. © 2021 American Society for Bone and Mineral Research (ASBMR).     

ASO Author Reflections: The Time to Incorporate Opioid-Minimizing Initiatives in Your Institution is now

Annals of Surgical Oncology -     

Pesticide exposure in a farming village in Venezuela--a developing country

This study was designed and performed by the Universidad de Carabobo, Centro de Investigaciones Toxicológicas, Venezuela, and the University of Cincinnati Department of Environmental Health. The authors tested methodology and analyzed preliminary data on demographics, pesticide use, health, environment, and lifestyles in a farming community in Venezuela (population = 386; sample size = 81) to determine if pesticide misuse might have been contributing to public health problems. Questionnaire and geographic information were collected. There were statistically significant incidences of pesticide-related symptoms (p < .01) in farmers versus nonfarmers (odds ratio = 5.7; 95% confidence interval = 2.9, 18.8). In addition, in one area there was a cluster of farmers who experienced symptoms that appeared to be the result of foul air and proximity to farms where there was pesticide use. The results of the study indicated that this public health problem may have been associated with pesticide misuse; however, additional studies are needed to corroborate the findings.     

Vasodilatory effect in rat aorta of eriodictyol obtained from Satureja obovata

The vasodilator effect of eriodictyol (5,7,3',4'-tetrahydroxyflavanone), isolated previously from the medicinal plant Satureja obovata Lag., was studied in rat thoracic aorta rings. Eriodictyol relaxed in a concentration-dependent manner the noradrenaline (10(-6) M) and KCl (80 mM) induced contractions. The relaxant effect was more potent in noradrenaline precontracted preparations (IC50 = 6.11 +/- 0.2 x 10(-5) M) than in those precontracted with KCl (IC50 = 2.96 +/- 0.1 x 10(-4) M). Eriodictyol produced weakly concentration-dependent inhibition of the phasic component induced by KCl and noradrenaline while the inhibition of the tonic phase of these contractions was more pronounced. These effects were endothelium independent. In addition, eriodictyol (10(-5) and 5 x 10(-5) M) inhibited CaCl2 cumulative concentration response curves. Eriodictyol weakly inhibited the release of calcium from the sarcoplasmic reticulum and its contribution to the relaxant effect seems to be slight. We have also observed the relaxant effect of eriodictyol on phorbol-12-myristate-13-acetate (PMA) (10(-7) M) induced contractions both in normal calcium (IC50 = 4.69 +/- 0.3 x 10(-5) M) and calcium-free medium (IC50 = 3.74 +/- 0.4 x 10(-5) M). Finally we studied the effects on protein kinase C (PKC) activity. This flavonoid did not show any activity. These results suggest that the vasodilator effect of eriodictyol in rat thoracic aorta could be partially related to the inhibition of calcium influx or other enzymatic protein subsequent to activation of PKC related to the activation of contractile proteins like myosin light chain kinase (MLCK).