Dietary Super-Doses of Cholecalciferol Fed to Aged Laying Hens Illustrates Limitation of 24,25-Dihydroxycholecalciferol Conversion

Background

Older humans taking high concentrations of vitamin D3 supplementation for a prolonged time may be at risk of vitamin D toxicity. It is unclear how dietary super-doses (10,000 times greater than the requirement) can affect vitamin D3 status in aged animals. Aged laying hens could be a model to compare vitamin D3 supplementation effects with women in peri- or postmenopausal stages of life.

Objectives

We investigated the dietary super-dose impacts of cholecalciferol (vitamin D3) on vitamin D3 status in aged laying hens in production.

Methods

Forty-eight 68-wk-old Hy-Line Brown laying hens were individually housed in cages with 8 hens per dietary treatment for 11 wk. Hens were randomly assigned to 1 of 6 treatment groups of dietary vitamin D3 supplementation and consumed ad libitum. Supplementation concentrations were 400, 800, 7400, 14,000, 20,000, and 36,000 IU D3/kg of feed. At the end of the study, all hens were sacrificed, and tissue samples and feces were collected. Plasma and egg yolk vitamin D3 metabolites, calcium and phosphorus composition of eggshells, ileal digesta, and feces were measured. Duodenal, ileal, liver, and kidney gene expression levels were also measured.

Results

We observed that increasing dietary vitamin D3 increased plasma vitamin D3 and egg yolk vitamin D3 (P < 0.0001 for both sites). We also observed an increase in plasma 24,25-dihydroxycholecalciferol as dietary vitamin D3 concentrations increased (P < 0.0001). The plasma 25-hydroxycholecalciferol:24,25-dihydroxycholecalciferol ratio exhibited an asymptotic relationship starting at the 14,000 IU/kg D3 treatment.

Conclusions

Dietary super-doses of vitamin D3 led to greater plasma and egg yolk vitamin D3 concentrations, which shows that aged laying hens can deposit excess vitamin D3 in egg yolk. We suggest future research should explore how 24-hydroxylation mechanisms are affected by vitamin D3 supplementation. Further understanding of 24-hydroxylation can help ascertain ways to reduce the risk of vitamin D toxicity.

Shaping human gut community assembly and butyrate production by controlling the arginine dihydrolase pathway

The arginine dihydrolase pathway (arc operon) present in a subset of diverse human gut species enables arginine catabolism. This specialized metabolic pathway can alter environmental pH and nitrogen availability, which in turn could shape gut microbiota inter-species interactions. By exploiting synthetic control of gene expression, we investigated the role of the arc operon in probiotic Escherichia coli Nissle 1917 on human gut community assembly and health-relevant metabolite profiles in vitro and in the murine gut. By stabilizing environmental pH, the arc operon reduced variability in community composition across different initial pH perturbations. The abundance of butyrate producing bacteria were altered in response to arc operon activity and butyrate production was enhanced in a physiologically relevant pH range. While the presence of the arc operon altered community dynamics, it did not impact production of short chain fatty acids. Dynamic computational modeling of pH-mediated interactions reveals the quantitative contribution of this mechanism to community assembly. In sum, our framework to quantify the contribution of molecular pathways and mechanism modalities on microbial community dynamics and functions could be applied more broadly.

Systems genetics approach uncovers associations between host amylase locus, gut microbiome and metabolic traits in hyperlipidemic mice

The molecular basis for how host genetic variation impacts gut microbial community and bacterial metabolic niches remain largely unknown. We leveraged 90 inbred hyperlipidemic mouse strains from the Hybrid Mouse Diversity Panel (HMDP), previously studied for a variety of cardio-metabolic traits. Metagenomic analysis of cecal DNA followed by genome-wide association analysis identified genomic loci that were associated with microbial enterotypes in the gut. Among these we detected a genetic locus surrounding multiple amylase genes that was associated with abundances of Firmicutes (Lachnospiraceae family) and Bacteroidetes (Muribaculaceae family) taxa encoding distinct starch and sugar metabolism functions. We also found that lower amylase gene number in the mouse genome was associated with higher gut Muribaculaceae levels. Previous work suggests that modulation of host amylase activity impacts the availability of carbohydrates to the host and potentially to gut bacteria. The genetic variants described above were associated with distinct gut microbial communities (enterotypes) with different predicted metabolic capacities for carbohydrate degradation. Mendelian randomization analysis revealed host phenotypes, including liver fibrosis and plasma HDL-cholesterol levels, that were associated with gut microbiome enterotypes. This work reveals novel relationships between host genetic variation, gut microbial enterotypes and host physiology/disease phenotypes in mice.

Screening for quality with process analytical technology in a health-system pharmacy: A primer

PURPOSE

The University of Kentucky Drug Quality Study team briefly reviews the growing concerns over pharmaceutical manufacturing quality in the globalized environment, reviews the historical approach by the US Food and Drug Administration (FDA) that prioritizes process over product in enforcing quality with manufacturers, reviews the science of process analytical technology (PAT) such as near-infrared (NIR) spectroscopy, illustrates the use of PAT methods for assessing uniformity and quality in injectable pharmaceuticals, and demonstrates the application of NIR spectroscopy in a health-system pharmacy setting while maintaining current good practice quality guidelines and regulations (cGxP).

SUMMARY

Given that the current approach to monitoring quality in pharmaceutical manufacturing was developed in the late 1960s at a time when manufacturing was mostly domestic, the current approach prioritizes process over product, and the global footprint of manufacturing is straining federal resources to fulfill their task of monitoring quality, an approach to augment the quality monitoring process has been developed. PAT methodologies are supported by FDA for monitoring quality and offer a fast, low-cost, nondestructive solution. Given that the Accreditation Council for Pharmacy Education has not required qualitative/quantitative analysis and drug assaying in the pharmacy curriculum for several decades, the authors spend time explaining the science behind one of these PAT methodologies, NIR spectroscopy. This primer reviews the application of this technology in the health-system pharmacy setting and the relevant clinical applications.

CONCLUSION

Utilizing PAT methodologies such as NIR spectroscopy, health-system pharmacies can gain insights about whether process controls are in place or lacking in FDA-approved formulations.

Application of Near-Infrared Spectroscopy for Screening of Chlorothiazide Sodium Vials

Chlorothiazide sodium for injection, USP, is a diuretic and antihypertensive medication in the form of a white or practically white, sterile, lyophilized powder. Each vial contains 500 mg of chlorothiazide sodium, equivalent to 500 mg of chlorothiazide, and 250 mg of mannitol as an inactive ingredient. The pH is adjusted with sodium hydroxide. Chlorothiazide sodium has a molecular weight of 317.71 amu. Since 2020 there have been multiple national shortages of chlorothiazide. Recent studies target chlorothiazide's low bioavailability, aiming to enhance it through nanoparticle production via a supercritical method. The drug's solubility in supercritical carbon dioxide (scCO2) is vital, with measurements ranging from 0.417×10-5 to 1.012×10-5 mole fraction under specific conditions. Adding co-solvents, like ethanol, DMSO, and acetone, to scCO2 boosts solubility, with ethanol proving most effective, enhancing solubility by 2.02-11.75 times. Intra-lot variability was discovered in a sample of a lot of chlorothiazide sodium by the University of Kentucky Drug Quality Task Force. Two vials of six screened in one lot were displaced from the center of the lot by 4.0 and 4.2 SDs, respectively. Inter-lot variability was confirmed in the near-IR spectra of 204 vials obtained from 28 different lots of chlorothiazide sodium. Using full spectrum BEST analysis 13 vials (6.4%) were outliers.

Assessment of Vecuronium Quality Using Near-Infrared Spectrometry

This study employed Fourier Transform near-infrared spectrometry to assess the quality of vecuronium bromide, a neuromuscular blocking agent. Spectral data from two lots of vecuronium were collected and analyzed using the BEST metric, principal component analysis (PCA) and other statistical techniques. The results showed that there was variability between the two lots and within each lot. Several outliers in the spectral data suggested potential differences in the chemical composition or sample condition of the vials. The outliers were identified and their spectral features were examined. A total of eight unique outliers were found in the PC space from PCs 1 to 9, so 22% of the total vials were outliers. The study findings suggest that the manufacturing process of vecuronium bromide may have been operating outside of a state of process control. Further investigation is needed to determine the source of these variations and their impact on the safety and efficacy of the drug product.

Implications of Vitamin D Research in Chickens can Advance Human Nutrition and Perspectives for the Future

The risk of vitamin D insufficiency in humans is a global problem that requires improving ways to increase vitamin D intake. Supplements are a primary means for increasing vitamin D intake, but without a clear consensus on what constitutes vitamin D sufficiency, there is toxicity risk with taking supplements. Chickens have been used in many vitamin-D-related research studies, especially studies involving vitamin D supplementation. Our state-of-the-art review evaluates vitamin D metabolism and how the different hydroxylated forms are synthesized. We provide an overview of how vitamin D is absorbed, transported, excreted, and what tissues in the body store vitamin D metabolites. We also discuss a number of studies involving vitamin D supplementation with broilers and laying hens. Vitamin D deficiency and toxicity are also described and how they can be caused. The vitamin D receptor (VDR) is important for vitamin D metabolism; however, there is much more to understand about VDR in chickens. Potential research aims involving vitamin D and chickens should explore VDR mechanisms that could lead to newer insights into VDR. Utilizing chickens in future research to help elucidate vitamin D mechanisms has great potential to advance human nutrition. Finding ways to increase vitamin D intake will be necessary because the coronavirus disease 2019 (COVID-19) pandemic is leading to increased risk of vitamin D deficiency in many populations. Chickens can provide a dual purpose with addressing pandemic-caused vitamin D deficiency: 1) vitamin D supplementation gives chickens added-value with the possibility of leading to vitamin-D-enriched meat and egg products; and 2) using chickens in research provides data for translational research. We believe expanding vitamin-D-related research in chickens to include more nutritional aims in vitamin D status has great implications for developing better strategies to improve human health.

Efficacy of 1-α-Hydroxycholecalciferol Supplementation in Young Broiler Feed Suggests Reducing Calcium Levels at Grower Phase

Increasing biopotency of cholecalciferol (D₃) from vitamin sources is essential in the poultry industry to meet nutritional demands and counter stressors. D₃ exhibits hormonal traits and is responsible for calcium (Ca) absorption. 1-α-Hydroxycholecalciferol (1α) is a synthetic form of D₃ that has equal efficacy and is cheaper to synthesize than 1,25-dihydroxycholecalciferol (active form of D₃), on broilers. However, 1α bypasses a critical regulatory point, the kidney, and may consequently lead to toxicity levels of Ca via Ca absorption. This study examined 1α supplementation in broiler diets with different Ca inclusion levels to determine if 1α at higher Ca levels caused Ca toxicity at starter and grower phases with Ross 708 male broiler chicks. In Experiment 1 (1–15 days of age), chicks were assigned to one of 10 treatment starter diets with five levels of Ca inclusion (0.80, 0.95, 1.10, 1.25, and 1.40%) with or without 1α supplementation (5 μg 1α/kg in feed) and eight replicate cages per treatment. In Experiment 2, chicks were fed common starter diet until 16 days of age, and then they were assigned to one of eight treatment diets with four levels of Ca inclusion (0.54, 0.76, 0.98, or 1.20%) with or without 1α supplementation (5 μg 1α/kg in feed). At the end of both experiments, blood was collected from broilers to determine blood chemistry, including concentrations of vitamin D metabolites. Intestinal tissues were also collected to examine gene expression. In Experiment 1, broilers not fed 1α exhibited a quadratic effect in ionized blood Ca (iCa) as dietary Ca inclusion levels increased; 1α-fed broilers displayed an increase in iCa as Ca inclusion levels increased (p = 0.0002). For Experiment 2, 1α-fed broilers displayed a decrease in 25-hydroxycholecalciferol plasma concentration as dietary Ca inclusion levels increased (p = 0.035); also, increasing Ca inclusion in diets increased expression of duodenal sodium phosphate cotransporter type II b (NPTIIb, p = 0.03). Our findings imply that inclusion of 1α was beneficial because 1α enhanced Ca absorption during the starter phase; however, to avoid potential Ca toxicity or antagonism while using 1α during the grower phase, there should be consideration with reducing dietary Ca levels.

Maternal Dietary Protein Intake Influences Milk and Offspring Gut Microbial Diversity in a Rat (Rattus norvegicus) Model

Historically, investigators have assumed microorganisms identified in mother’s milk to be contaminants, but recent data suggest that milk microbiota may contribute to beneficial maternal effects. Microorganisms that colonize the gastrointestinal tracts of newborn mammals are derived, at least in part, from the maternal microbial population. Milk-derived microbiota is an important source of this microbial inocula and we hypothesized that the maternal diet contributes to variation in this microbial community. To evaluate the relationship between a mother’s diet and milk microbiome, we fed female rats a low- or high-protein diet and mated all individuals. Milk and cecal contents were collected from dams at peak lactation (14-day post-partum), and the bacterial composition of each community was assessed by 16S rRNA gene amplicon sequencing. Our findings revealed higher dietary protein intake decreased fecal microbial diversity but increased milk microbial and pup cecum diversity. Further, the higher dietary protein intake resulted in a greater abundance of potentially health-promoting bacteria, such as Lactobacillus spp. These data suggest that dietary protein levels contribute to significant shifts in the composition of maternal milk microbiota and that the functional consequences of these changes in microbial inocula might be biologically important and should be further explored.

THE ABSORPTION OF PROTEIN SOLUTIONS FROM THE PULMONARY ALVEOLI

Horse serum, crystallized hemoglobin, and crystallized egg albumin have been injected into the lung alveoli of dogs in which the entrances of the right lymphatics have been tied and the thoracic duct cannulated. Samples of blood and lymph have been taken following this injection. Only after several hours in the case of the horse serum and hemoglobin have these proteins been detected by immunological methods and invariably they have appeared first in the blood. Egg albumin also enters the blood capillaries, but much more rapidly than the other two proteins, due probably to the smaller molecular size.

THE PASSAGE OF RABBIT VIRULENT TYPE III PNEUMOCOCCI FROM THE RESPIRATORY TRACT OF RABBITS INTO THE LYMPHATICS AND BLOOD

1. Rabbit virulent Type III pneumococci when instilled into the nose or trachea were recovered from the lymphatics draining the area involved in the lymph collected during a subsequent 4 hour period. Their detection rarely failed, and not infrequently was possible at the end of the 1st hour. 2. The organisms practically invariably appeared first in the lymphatics and subsequently in a few cases were recovered from the blood during the 4 hour test period. 3. The intravenous administration of antiserum 2½ to 3 hours before the instillation of organisms decreased the number of animals whose lymph or blood became positive and the total length of time in which organisms were recovered in lymph from the efferent lymphatics during the test period.

Effects of stimulus level on nonspectral frequency discrimination by human subjects

Frequency difference limens were determined as a function of reference-stimulus level for pulsatile electrical stimuli in 5 postlingually deaf human subjects with Nucleus-22 cochlear implants and for sinusoidally amplitude-modulated acoustic white noise stimuli in 4 normal-hearing humans. Subjects were tested at levels throughout the dynamic range and extending to the lowest detectable levels. Response stability was measured over the course of 10 sessions. For electrical stimulation in the deaf ears, difference limens decreased as a function of level throughout much or all of the dynamic range of hearing. This result contrasts with the case for nonspectral acoustic stimulation of normal-hearing subjects, where nonspectral frequency difference limens were strongly affected by level only near the detection threshold. These data suggest differences in the acoustic and electrical response spaces that must be considered in the design of auditory prosthesis processors.

Glycogen storage disease type X caused by ochratoxin A in broiler chickens

Day-old broiler chickens fed graded concentrations of ochratoxin A (0, .5, 1.0, 2.0, 4.0, and 8.0 micrograms/g of diet) for 3 weeks were examined histopathologically for glycogen accumulation in muscle tissue using both formalin and ethanol fixatives with periodic acid-Schiff stain in a duplicate diastatic slide technique. However, glycogen could not be visualized in chicken muscle by these techniques which work with human muscle. Quantitative analysis for the glycogen itself permitted demonstration of a significant (P less than .05) fourfold increase in birds fed 8 micrograms/g. Using startled birds demonstrated that this accumulated glycogen was about 99% physiologically available. These findings coupled with prior reports permit the assignment on morphologic criteria of the hyperglycogenation of ochratoxicosis as a type X glycogen storage disease.

Inhibition of the glycogen phosphorylase system during ochratoxicosis in chickens

Graded doses of ochratoxin A incorporated into the diet (0, 0.5, 1.0, 2.0, 4.0, and 8.0 micrograms/g) of broiler chickens significantly (P < 0.05) inhibited activity of protein kinase, the initiator enzyme of the glycogen phosphorylase system, in the livers at all dose levels. Only the highest dose, 8.0 micrograms/g, significantly reduced the total activity of phosphorylase kinase, which is activated by protein kinase. The total activity of phosphorylase, which is activated by phosphorylase kinase, was unaltered by ochratoxin A at any level. Additon of ochratoxin A to liver extracts control birds inhibited protein kinase but not phosphorylase kinase. When added to extracts of livers from control birds, cyclic adenosine 3',5'-monophosphate stimulated protein kinase but not phosphorylase kinase. The cyclic adenosine 3',5'-monophosphate had no effect when added to extracts from birds fed ochratoxin A. These results suggest that ochratoxin A affects primarily the cyclic adenosine 3',5'-monophosphate-dependent protein kinase which initiates the enzymatic cascade leading to glycogenolysis. Furthermore, these results conform an earlier assignment on morphological criteria of the glycogenosis of ochratoxicosis as a type X glycogen storage disease.

Intestinl fragility during ochratoxicosis and aflatoxicosis in broiler chickens

Graded concentrations of dietary ochratoxin (0, 0.5, 1.0, 2.0, 4.0, and 8.0 microgram/g) and aflatoxin (0, 0.625, 1.25, 2.5, 5.0, and 10.0 microgram/g) were fed to broiler chicks from hatching to 3 weeks of age. The breaking strength of the large intestines was decreased significantly (P < 0.05) by ochratoxin (2, 4, and 8 microgram/g), but not by aflatoxin. This fragility was accompanied by an increase in the weight of the large intestine relative to body weight of birds fed ochratoxin (4.0 and 8.0 microgram/g), whereas aflatoxin had no significant (P < 0.05) effect on this parameter. Lipid content of the large intestine was decreased significantly (P < 0.05) by aflatoxin (10.0 microgram/g) and increased by ochratoxin (8.0 microgram/g). Microscopic examination of cross sections of large intestines stained for collagen gave the impression of a great decrease in collagen content of birds fed ochratoxin, but not aflatoxin. The radial length of the collagenous longitudinal folds of the large intestine was decreased significantly (P < 0.05) by ochratoxin (2.0, 4.0, and 8.0 microgram/g). These observations, plus a field case characterized by intestinal ruptures causing carcass condemnations on the processing line and by the occurrence of aflatoxin and ochratoxin in the chicken feed, suggest a novel way in which mycotoxins cause economic loss to agriculture.

Ochratoxin A-induced iron deficiency anemia

Ochratoxin A at 8 micrograms per g of diet, but not at lower doses, fed to chickens from 1 day to 3 weeks of age resulted in significantly (P less than 0.05) decreased packed blood cell volume and hemoglobin concentration without altering the number of circulating erythrocytes. Serum iron and percentage of transferrin saturation were lowered at 4 and 8 micrograms/g. Therefore, anemia was characteristic of severe ochratoxicosis of young chickens, and the anemia was categorized as a hypochromic-microcytic anemia of the iron deficiency type. These data indicate that ochratoxin A by itself does not cause hemorrhagic anemia syndrome of chickens and that an anemia caused by a nutritional deficiency can be elicited by a mycotoxin.