Whole body passive heating versus dynamic lower body exercise: a comparison of peripheral hemodynamic profiles.

Passive heating has emerged as a therapeutic intervention for the treatment and prevention of cardiovascular disease. Like exercise, heating increases peripheral artery blood flow and shear rate, which is thought to be a primary mechanism underpinning endothelium-mediated vascular adaptation. However, few studies have compared the increase in arterial blood flow and shear rate between dynamic exercise and passive heating. In a fixed crossover design study, 15 moderately trained healthy participants (25.6 ± 3.4 yr) (5 female) underwent 30 min of whole body passive heating (42°C bath), followed on a separate day by 30 min of semi-recumbent stepping exercise performed at two workloads corresponding to the increase in cardiac output (Qc) (Δ3.72 L·min-1) and heart rate (HR) (Δ40 beats/min) recorded at the end of passive heating. At the same Qc (Δ3.72 L·min-1 vs. 3.78 L·min-1), femoral artery blood flow (1,599 mL/min vs. 1,947 mL/min) (P = 0.596) and shear rate (162 s-1 vs. 192 s-1) (P = 0.471) measured by ultrasonography were similar between passive heating and stepping exercise. However, for the same HRMATCHED intensity, femoral blood flow (1,599 mL·min-1 vs. 2,588 mL·min-1) and shear rate (161 s-1 vs. 271 s-1) were significantly greater during exercise, compared with heating (both P = <0.001). The results indicate that, for moderately trained individuals, passive heating increases common femoral artery blood flow and shear rate similar to low-intensity continuous dynamic exercise (29% V̇o2max); however, exercise performed at a higher intensity (53% V̇o2max) results in significantly larger shear rates toward the active skeletal muscle.NEW & NOTEWORTHY Passive heating and exercise increase blood flow through arteries, generating a frictional force, termed shear rate, which is associated with positive vascular health. Few studies have compared the increase in arterial blood flow and shear rate elicited by passive heating with that elicited by dynamic continuous exercise. We found that 30 min of whole body passive hot-water immersion (42°C bath) increased femoral artery blood flow and shear rate equivalent to exercising at a moderate intensity (∼57% HRmax).

Application of direct contact membrane distillation for saline dairy effluent treatment: performance and fouling analysis.

Membrane distillation is getting increasing attention thanks to its advantages in terms of energy consumption and final permeate quality in addition to its resistance against highly corrosive media which forms an appealing solution for industrial wastewater treatment. Despite its advantages, one of the most challenging issues in direct contact membrane distillation (DCMD) is membrane fouling and wetting. In the present research work, saline dairy effluent discharged from hard cheese industry was pretreated by macrofiltration (MAF) and ultrafiltration (UF) and processed by DCMD to investigate the extent of the aforementioned issues. Effluents pretreated by UF have led the best process performance with stable flux values at different operating conditions. Fouling has occurred in all the experiments, though their effect on the flux behavior and membrane wetting was different from one feed to the other. Changing the flow rate and the temperature difference have affected slightly the membrane wettability for all feed qualities. In all experiments, the permeate has maintained a good quality with low electrical conductivity that did not exceed 70 µS/cm and low total organic carbon < 2 mg/L.

Chronic psychosocial stress disturbs long-bone growth in adolescent mice.

Although a strong association between psychiatric and somatic disorders is generally accepted, little is known regarding the interrelationship between mental and skeletal health. Although depressive disorders have been shown to be strongly associated with osteoporosis and increased fracture risk, evidence from post-traumatic stress disorder (PTSD) patients is less consistent. Therefore, the present study investigated the influence of chronic psychosocial stress on bone using a well-established murine model for PTSD. C57BL/6N mice (7 weeks old) were subjected to chronic subordinate colony housing (CSC) for 19 days, whereas control mice were singly housed. Anxiety-related behavior was assessed in the open-field/novel-object test, after which the mice were euthanized to assess endocrine and bone parameters. CSC mice exhibited increased anxiety-related behavior in the open-field/novel-object test, increased adrenal and decreased thymus weights, and unaffected plasma morning corticosterone. Microcomputed tomography and histomorphometrical analyses revealed significantly reduced tibia and femur lengths, increased growth-plate thickness and reduced mineral deposition at the growth plate, suggesting disturbed endochondral ossification during long-bone growth. This was associated with reduced Runx2 expression in hypertrophic chondrocytes in the growth plate. Trabecular thicknesses and bone mineral density were significantly increased in CSC compared to singly housed mice. Tyrosine hydroxylase expression was increased in bone marrow cells located at the growth plates of CSC mice, implying that local adrenergic signaling might be involved in the effects of CSC on the skeletal phenotype. In conclusion, chronic psychosocial stress negatively impacts endochondral ossification in the growth plate, affecting both longitudinal and appositional bone growth in adolescent mice.

Microbiological diagnosis and antibiotic therapy in patients with community-acquired pneumonia and acute COPD exacerbation in daily clinical practice: comparison to current guidelines.

BACKGROUND: The aim of this secondary analysis was to evaluate current microbiological approaches, microbiology, and antibiotic therapy in patients with community-acquired pneumonia (CAP) and acute exacerbation of chronic obstructive pulmonary disease (AECOPD) in clinical practice and to compare them with current international guidelines. METHODS: A total of 362 patients with suspected CAP were enrolled in 14 European centers in a prospective multicenter study. RESULTS: A total of 279 inpatients (CAP, n = 222; AECOPD, n = 57) were evaluated. A total of 83 (37 %) CAP patients and 25 (44 %) AECOPD patients did not undergo any microbiological tests. In patients with CAP/AECOPD, blood culture was performed in 109 (49 %)/16 (28.1 %), urinary antigen tests for Legionella pneumophila in 67 (30 %)/9 (16 %), and sputum investigation in 55 (25 %)/17 (30 %), respectively. The most frequent pathogens in CAP were Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae, L. pneumophila, Staphylococcus aureus, and Enterobacter cloacae; in AECOPD they were Escherichia coli, Haemophilus haemolyticus, Haemophilus influenzae, and Moraxella catarrhalis. All CAP patients (mean = 11.1 days) and 35 (61.4 %) of AECOPD patients (mean = 8.9 days) received antibiotics. CAP patients were given mostly aminopenicillin with ß-lactamase inhibitors and AECOPD patients were given mostly cephalosporins. CONCLUSIONS: Pathogens isolated in CAP and AECOPD and the antibiotic therapy used are in good accordance with the guidelines. Blood culture, recommended for all CAP patients, was performed in only 50 % of the cases and antibiotic therapy lasted longer than the suggested 5-7 days. Therefore, international guidelines regarding performance of blood culture and duration of antibiotic therapy should be adopted more often. This duration was independent of the number of isolated pathogens and number of symptoms on admission. Therefore, the question arises as to whether microbiological data are necessary only for patients who are resistant to initial therapy.

Reactions of pyrazolylborate-zinc-hydroxide complexes related to beta-lactamase activity.

Simple beta-lactams and their hydrolysis products, the beta-amino acids, react with TpZn-OH under deprotonation. The latter become semibidentate carboxylate ligands with a NH...O hydrogen bond, and the former become N-bound beta-lactamide ligands. Likewise the antibiotic derivatives 6-aminopenicillanic acid and 7-aminocephalosporanic acid are incorporated as carboxylate ligands. beta-Lactams bearing nitrophenyl or acyl substituents at the nitrogen atoms are opened hydrolytically by TpZn-OH, and the resulting N-substituted beta-amino acids are attached to zinc by their carboxylate functions. Only with trifluoroacetyl as the N-substituent does the hydrolytic cleavage occur at the external amide bond, yielding the free beta-lactam and TpZn-trifluoroacetate. The kinetic investigation of the opening reactions has shown them to be of second order like all other TpZn-OH-induced hydrolytic cleavages, thereby supporting the four-center mechanism for the monozinc beta-lactamases.

Zinc complex chemistry of N,N,O ligands providing a hydrophobic cavity.

Three new highly substituted bis(2-picolyl)(2-hydroxybenzyl)amine ligands were synthesized, and their biomimetic zinc complex chemistry was explored. They have tert-butyl substituents at the 3-and 5-positions of their phenyl rings, and they bear one phenyl group (HL2), two methyl groups (HL3), or two phenyl groups (HL4) at the 6-positions of their pyridyl rings. Their reactions with hydrated zinc perchlorate yield three distinctively different complex types. L2 forms a trigonal-bipyramidal aqua complex, and L3, a square-pyramidal aqua complex. The substituents on L4 leave no room for a water ligand, and the resulting zinc complex is trigonal-monopyramidal with a vacant coordination site. The water ligands on the L2Zn and L3Zn units can be replaced by anionic halide, thiocyanate, p-nitrophenolate, benzoate, and organophosphate as well as uncharged pyridine ligands. The L4Zn unit forms labile halide, p-nitrophenolate, and pyridine complexes. Triethylamine converts the aqua complexes to the labile hydroxides L2Zn-OH and L3Zn-OH, and in polar media [L3Zn-OH2]+ seems to be in equilibrium with L3Zn-OH. The hydroxides, but not the water complexes, effect the hydrolytic cleavage of tris(p-nitrophenyl) phosphate to bis(p-nitrophenyl) phosphate. The kinetic investigation of the cleavage reactions has shown them to be second-order reactions, thereby supporting the proposed four-center mechanism.