Effect of Diet Supplementation with the Mycotoxin Binder Montmorillonite on the Bioavailability of Vitamins in Dairy Cows

The objective of this study was to determine the effect of the mycotoxin binder montmorillonite (MMT) supplemented in the diet of dairy cows on the bioavailability of vitamins A, D, E, B1 and B6. Six multiparous Holstein-Friesian cows were used in a crossover design with two periods. Treatments were a control diet with or without MMT. Vitamins were infused individually into the abomasum through the ruminal cannula. Blood samples were collected from the jugular vein at 0, 1, 2, 3, 4, 6, 9, 12, 24 and 48 h after the administration of each vitamin. Results showed that vitamin A reached maximal concentration (Tmax) at 5.3 h after dosing, the maximal concentration (Cmax) was 1.2 times higher than the basal concentration (Cbasal), and the area under the curve (AUC) was 739 arbitrary units. Vitamin B6 reached the Tmax at 13 h after dosing, the Cmax was 1.4 times higher than the Cbasal, and the AUC was 222 arbitrary units. No differences were observed in Cbasal, Tmax, Cmax and AUC of vitamin A and B6 between control vs. MMT-supplemented cows. Plasma concentrations of vitamins D, E and B1 had no concentration peaks, and were not affected by MMT addition. The lack of a response suggests that their plasma concentration may be tightly regulated. Results of this study do not show evidence that MMT affects the bioavailability of vitamins A and B6 in vivo.

Analysis of thermal-electrical performance of PVT collector with reflectors

<span lang="EN-US">This work concerns numerical studies of PVT air collector operating in dynamic mode. We presented the temperature of the solar cells and of the air at the outlet of the PVT collector with and without reflectors. The obtained simulation results has been validated by comparating with the experimental results available in literature, where good agreement was been noted. In addition, we determine the optimal position of the reflectors by numerical calculation, in order to obtain the maximal concentration of the solar radiation intensity on PV/T collector. </span><span lang="EN-US">The thermal and electrical efficiency of PV/T collector without reflectors and with reflectors in optimal position have been calculated for composite climate at Tetouan (-5°N, 35.5°E). </span><span lang="EN-US">So, the effect of adding solar reflectors on the electrical and thermal performance </span><span lang="EN-US">is showing</span><span lang="EN-US">.</span>

Melanocortin 2 Receptor Antagonists in Canine Cushing’s Disease: In Vitro Studies

Melanocortin 2 receptor antagonists in canine Cushing’s disease: in vitro studies Cushing’s disease (CD), caused by an ACTH-secreting pituitary adenoma, is one of the most common endocrinopathies in dogs. The current medical treatment options involve adrenocortical steroid synthesis inhibitors, but a selective targeted approach to block ACTH receptor at its receptor would be much more attractive. The objective of this study was to preclinically investigate the effect of MC2R antagonists on adrenocortical hormone production, cell viability, and mRNA expression of steroidogenic enzymes in canine primary adrenocortical cell cultures from adrenal glands of healthy dogs. Three different MC2R antagonists were used: CRN.1, CRN.2, and CRN.4. Canine primary adrenocortical cell cultures (n = 8) were incubated with 50 nM ACTH for 24h, to mimic CD. Thereafter, 10 nM (IC50) and 2 μM (maximal concentration) of CRN.1, CRN.2, and CRN.4 were added. The two concentrations were established based on preliminary studies. After 24 hours of incubation, adrenocortical hormone concentrations were measured in the culture medium using liquid chromatography-mass spectrometry. RNA was isolated from the cells using the RNeasy Microkit (Qiagen) for subsequent real-time quantitative PCR analysis. Cell viability was assessed after 24 hours of incubation using alamarBlue™ Cell Viability Reagent. All CRN compounds effectively inhibited cortisol concentrations, while leaving aldosterone concentrations unaffected. In incubations with a maximal concentration of the three compounds, cortisol concentration decreased to undetectable levels. The mRNA expression levels of steroidogenic enzymes StAR, CYP11A1, CYP17A1, HSD3B2, CYP21, and CYP11B were significantly inhibited in most conditions when compared to the ACTH-stimulated control. The mRNA expression of melanocortin 2 receptor accessory protein (MRAP) was suppressed as well. Cell viability was not affected by CNR.1 or CNR.4, but was slightly inhibited by CRN.2. In summary, canine adrenocortical cell culture is a useful model system for drug testing. Incubation with MC2R antagonists demonstrated the potential of CNR.1 and CNR.4 as new treatment options for CD. Future in vivo studies in dogs with spontaneous CD are indicated.

Testing of Adrenal Axis Function in Patients With Combined Pituitary Hormone Deficiency Caused by PROP1 Mutation

Background: The mechanism of adrenal axis deterioration in PROP1 mutation remains uncertain and challenging. Aim: The aim of the project was to investigate the adrenal axis function in patients with combined pituitary function deficiency and PROP1 mutation. Methods: We performed the corticotrophin (CRH) stimulation test in 15 patients ((8W/7M) with confirmed CPHD due to the PROP1 mutation. 9/15 were familial cases from four families. Time of observation (ToO) was calculated since the first pituitary axis/ACTH insufficiency has occurred. The results were reported in the group with confirmed Adrenal Insufficiency (AI) and without AI defined as cortisol &gt;18 ug/dl at any point during CRH test. ACTH is reported in pg/ml and cortisol in ug/dl, time of test is given in minutes (0‘, 15’,30’,45’,60’,120’). Results: The mean age of the group was 40,6 ± 12,1 years with mean 34,7 ± 10,3 years of CPHD observation (range 18 – 54 years). The In 5/15 the cortisol response met the criteria excluding AI. Among siblings there were patients both with/without AI. Both subgroups had similar ToO (without AI 35,6 ± 10,0 years vs 34,2 ± 10,3 years with AI). Mean time of AI duration was 15,0 ± 9,3 years. In the group of 5 patients without AI the mean morning cortisol was 12,48 ± 4,31 and ACTH was 31,26 ± 5,43. The mean maximal concentration of cortisol and ACTH were 24,94 ± 3,6 and 123,6 ± 39,9 respectively; Mean increase of cortisol was 12,46 ±4,04 and 92,34±34,48 for ACTH. In 10 patients with AI the mean morning cortisol was 3,33±1,39 and ACTH 22,71±6,75. The mean maximal concentration of cortisol and ACTH were 10,15±4,47 and 97,05 ± 59,15 respectively; Mean increase of cortisol was 6,83 ± 3,41 and 74,35 ± 53,72 for ACTH. For two patients high ACTH increase from 36,7 to 260 and from 28,65 to 112,0 was observed. Analysis of cortisol and ACTH response in both groups revealed that in group without AI the time of peak of ACTH was observed in 15’ (2/5) and 30’ (3/5) vs. in 15’(3/10), 30’(6/10) and 45’ in group with AI. The peak cortisol was observed in 30’, 45’ and 60’ (3/5) in group without AI vs 60’(6/10) or 120’ (4/10) in AI group. The mean maximal increase of ACTH was by 4,09±1,46 and 4,12±1,58 in AI group vs no AI group respectively. Conclusions: In patients with PROP1 mutation the adrenal axis can deteriorate long after other axis insufficiencies, however there are patients with no adrenal insufficiency even during lifelong observation. There is no specific order of deterioration even among affected siblings. In the vast majority of patients independently of cortisol increase there is ACTH response after CRH. Further studies on the pituitary function deterioration in patients with PROP1 mutation should be carried out to understand better the underlying mechanism and to set up the diagnostic timing and procedures.

Description of Plasma Penicillin G Concentrations after Intramuscular Injection in Double-Muscled Cows to Optimize the Timing of Antibiotherapy for Caesarean Section

In order to improve the efficacy of penicillin injection during caesarean section, we aimed to identify the optimal timing of its preoperative administration. A study was conducted in 12 adult, non-pregnant Belgian Blue cows. To evaluate the plasma penicillin concentrations, blood samples were taken from the jugular vein at −5, 15, 30, 45, 60, 120, 240, 480 min relative to the intramuscular (IM) injection of 21,000 IU/kg of body weight of penicillin G. Results showed that plasma concentrations at 15 min after IM injection (668.3 ± 73.7 ng/mL) largely exceeded the minimal inhibitory concentration (MIC) of penicillin-sensitive bacteria (MIC < 125 ng/mL). With increasing time, plasma concentrations continued to rise, attaining an increasing proportion of moderately sensitive bacteria (250 ng/mL > MIC < 2000 ng/mL). The maximal concentration was reached between 1 and 4 h (average: 1.495.1 ± 181.7 ng/mL) after IM injection in the majority of cows, and decreased non-significantly to 1002.1 ± 93.2 ng/mL at 8 h. In conclusion, plasma penicillin concentrations at 15 min after an IM injection inhibit penicillin-sensitive bacteria. However, in order to obtain the maximal protective effect of the antibiotherapy, surgery should be started at 1 to 2 h after IM penicillin injection.

Analyses of Commercially Available Alcohol-Based Hand Rubs Formulated with Compliant and Non-Compliant Ethanol

The COVID-19 pandemic led to panic-buying of alcohol-based hand rubs (ABHRs). In response, governmental agencies (e.g., Health Canada) permitted the sale of ABHRs formulated with “technical-grade” ethanol to alleviate the growing demand. Technical-grade ethanol contains elevated concentrations of impurities (e.g., acetaldehyde, etc.), which may exhibit dose-dependent toxicity. In this study, a rapid solvent extraction was employed to analyze gelled ABHRs via gas chromatography with flame ionization detection. In total, 26 liquid and 16 gelled ABHRs were analyzed for nine common impurities to determine compliance with Health Canada interim guidelines. Of 42 samples analyzed, 11 ABHRs appear to be non-compliant with interim Health Canada guidelines. Non-compliant ABHRs exhibited elevated concentrations of acetaldehyde, with a maximal concentration observed of 251 ± 10 µL L−1; 3.3× higher than currently permitted. Nonetheless, frequent testing of ABHRs should be routinely conducted to reduce the risk of consumer exposure to non-compliant ABHRs.

Colorimetric Quantification Methods for Peracetic Acid together with Hydrogen Peroxide for Water Disinfection Process Control

Peracetic acid (PAA) water solutions is applied for disinfection of industry systems, food products and non-potable water. Commercially available peracetic acid is always supplied mixed with hydrogen peroxide (H2O2). H2O2 degrade slower than the peracetic acid which creates a need to quantify both peroxides separately to gauge the disinfection power of the solution and the residuals. Two combinations of colorimetric reactions are presented that allows simultaneous quantification at the mg·L−1 level used in disinfection liquids and water disinfection. The first dichromic reaction use titanium oxide oxalate (TiO-Ox) which only react with H2O2 followed by addition of N,N-diethyl-p-phenylenediamine with iodide (DPD/I−) and the concentrations are read by simultaneously measuring the absorbance at 400 and 515 nm. Limit of quantification (LOQ) and maximal concentration determined was 4.6 µg·L−1 and 2.5 mg·L−1 for PAA and 9.1 µg·L−1 and 5 mg·L−1 for H2O2. The two color reactions didn’t interfere with each other when the reagent addition was consecutive. Another combination of colorimetric reaction also used where TiO-Ox was used to first measure H2O2 at 400 nm, before addition of 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS)) and reading the absorbance at 405 nm. ABTS changes the absorbance at 405 nm necessitating the two measurements be done separately. LOQ and maximal concentration determined using ABTS colorimetric assay was 42.5 µg·L−1 and 30 mg·L−1 for PAA and for titanium oxide oxalate colorimetric assay was 12.7 µg·L−1 and 75 mg·L−1 for H2O2. Both methods tested satisfactory in typical water samples (Tap, sea, lake, and biological treated sewage) spiked with peracetic acid and H2O2, separately.

Rational dosing of HCQ for COVID-19_pre-print

Background: Hydroxychloroquine (HCQ) has in vitro activity against SARS-CoV-2. However, datato inform optimal human dosing are limited.Methods: We conducted Monte Carlo simulations of HCQ sulfate using a published populationpharmacokinetic model. The model informing our simulations described a 2-compartmentlinear model with first-order absorption with a lag, derived from plasma HCQ concentrationdata from 22 healthy adults and 69 patients with malaria. Using the final PK model, we performed 1000 simulations for the plasma concentrations of HCQ sulfate based on various approved dosages (i.e. acute malaria, autoimmune conditions) and proposed dosing regimensfor treatment of COVID-19. The results of simulations were used to derive the area under the concentration-time curve (AUC), maximal concentration, and time to maximal concentration for each evaluated regimen.Results: The use of a loading dose, as with acute malaria dosing, resulted in rapid achievementof maximal concentrations early in the treatment course, which were maintained with dailydosing thereafter. The use of once or twice daily doses without a loading dose led to slowlyincreasing plasma concentrations through day 10. Simulated regimens that employed an 800mg loading dose for adults (13 mg/kg for children) followed by 400 mg at 6 or 12 hours (6.5mg/kg for children) achieved the greatest AUC0-24.Conclusions: Based on our findings, along with established safety data from malarial studies,we believe that approved dosing for treatment acute malaria is the most reasonable and safestapproach if HCQ will be used to treat COVID-19.

Intra-articular concentration of gentamicin administered by intravenous regional limb perfusion in healthy horses

ABSTRACT: Intravenous regional limb perfusion (IRLP) is an efficient method to treat horses with synovial infections. However, information on the dose, volume, and intervals of administration is lacking. The aim of this study was to evaluate the intra-articular concentration of gentamicin administered by IRLP in horses over 24 h post-administration and evaluate the influence of the total perfused volume. Twenty horses were assigned to two treatment groups. Gentamicin 60 group (G60, n=10) and Gentamicin 250 group (G250, n=10) received IRLP of 6.6 mg/kg of gentamicin diluted in Ringer’s lactate for a total volume of 60 ml (G60) and 250 ml (G250), respectively. Synovial fluid harvests were performed in the metacarpophalangeal joint before (0) and 4, 8, 12, 16, 20, and 24 hours after IRLP. Agar diffusion was the assay for measuring gentamicin concentrations. Four hours after IRLP, the intra-articular concentration of gentamicin was 47.58±49.21 μg/ml in G60 and 10.92±6.11 μg/ml in G250. During the 24 h of harvest, the intra-articular concentration of gentamicin remained above the minimum inhibitory concentration for horses (MIC; 2 μg/ml) in both experimental groups. In G60, the concentration of gentamicin in synovial fluid reached the maximal concentration and remained 8 to 10-fold higher than the MIC (Cmax: 16 to 20 μg/ml) during 12 h after IRLP. These findings support that IRLP with 6.6 mg/kg of gentamicin diluted to a volume of 60 ml promotes intra-articular concentrations higher than 250 ml, remaining above the MIC for 24 h and at the maximum concentration for 12 h.