An overview on the correlation between blood zinc, zinc intake, zinc supplementation and bone mineral density in humans

INTRODUCTION

In case of zinc (Zn) deficiency, this mineral becomes a nutrient limiting muscle and bone synthesis. The study in humans on zinc and bone health are few and no reviews have been published on this topic. So, the aim of this narrative review was to consider the state of the art on the correlation between blood zinc, daily zinc intake, zinc supplementation and bone mineral density.

MATERIAL AND METHODS

A narrative review was performed.

RESULTS

This review included 16 eligible studies: eight studies concern Zn blood; three studies concern Zn intake and five studies concern Zn supplementation.

CONCLUSION

Blood zinc levels seem to be lower in subjects with pathology related to bone metabolism. Regarding daily zinc intake, a high proportion of the population, more than 20%, seems to be at risk of having inadequate zinc intake. The literature suggests that an insufficient zinc intake (less than 3 mg/day) could be a risk factor for fractures and for development of osteopenia and osteoporosis. Zinc supplementation (40-50 g/day) could have beneficial effects on bone health in terms of maintaining bone mineral density and faster healing in the event of fractures, with even better results in situations of reduced intake zinc through food.

Polycystic ovary syndrome management: a review of the possible amazing role of berberine

PURPOSE

The therapy of polycystic ovary syndrome (PCOS) is based on synthetic hormones associated with lifestyle changes, but these therapies cannot be taken continuously, especially by women who would like to become pregnant. Thus, nutraceutical compounds were investigated as possible agents for treatment of PCOS. Berberine is shown to be effective against insulin resistance and obesity, particularly against visceral adipose tissue (VAT). Because of these properties, researchers theorized that berberine could be effective in PCOS treatment.

METHODS

The aim of this narrative review was to assess the state of the art about the use of berberine in PCOS management.

RESULTS

This review included 5 eligible studies. Despite the number of studies considered being low, the number of women studied is high (1078) and the results are interesting. Two authors find out that berberine induced a redistribution of adipose tissue, reducing VAT in the absence of weight loss and improved insulin sensitivity, quite like metformin. One author demonstrated that berberine improved the lipid pattern. Moreover, three authors demonstrated that berberine improved insulin resistance in theca cells with an improvement of the ovulation rate per cycle, so berberine is also effective on fertility and live birth rates.

CONCLUSIONS

Finally, berberine is safe to use in premenopausal women who want to get pregnant and showed few side effects in all the cited studies. In conclusion, the use of berberine for PCOS is safe and promising, even if more studies are needed to create a consensus about the dosage of berberine useful for long-term therapy.

Does endogenous GLP-1 affect resting energy expenditure and fuel selection in overweight and obese adults?

PURPOSE

To investigate the association between fasting glucagon-like peptide 1 (GLP-1) levels and resting energy expenditure (REE), and respiratory quotient (RQ) in overweight and obese adults.

METHOD

Study participants were enrolled at the Dietetic and Metabolic Unit, University of Pavia, Italy. Inclusion criteria were age ≥ 25 and ≤ 45 years, and body mass index (BMI) ≥ 25 and ≤ 35 kg/m². Diabetic subjects were excluded. Body composition was measured by dual-energy X-ray absorptiometry. REE was evaluated using indirect calorimetry, and RQ was calculated from respiratory gas exchanges. Fasting GLP-1, glucose, insulin and free fatty acid (FFA) levels, and 24-h norepinephrine urinary excretion were measured. Homeostasis model assessments of insulin resistance (HOMA-IR) and beta-cell function (HOMA-β) were calculated.

RESULTS

Thirty-seven participants were included (age 43.4 ± 1.6 years; BMI 30.6 ± 0.5 kg/m²). REE was not associated with fasting GLP-1 levels (p = 0.98) after adjustment for age, sex, fat-free mass (FFM), and fat mass (FM). Similarly, no association was observed between RQ and GLP-1 levels (p = 0.95), after adjustment for age, sex, and body fat.

CONCLUSION

In adults subjects with increased adiposity fasting, GLP-1 levels do not seem to play a role in the regulation of energy metabolism and in fuel selection.

Application of excess activated sludge ozonation in an SBR Plant. Effects on substrate fractioning and solids production

This paper provides new insights on the application of the ozonation process for the reduction of the activated sludge production in a sequencing batch reactor (SBR). The study was performed in two identical lab-scale SBRs plant, one for experimental activities (Exp SBR) and one used as control (Control SBR), both fed with domestic sewage. A fraction of the activated sludge collected from the Exp SBR at the end of the aerobic react phase was periodically subjected to ozonation for 30 minutes at three different specific dosages (0.05, 0.07 and 0.37 g O(3)/gSS) and then recirculated before the beginning of the following cycle.Recirculation of the ozonated sludge to the Exp SBR did not appreciably affect the efficiency of the biological nitrogen and carbon removal processes. Nonetheless, an improvement of the denitrification kinetic was observed. Mixed liquor volatile and suspended solids (MLSS and MLVSS, respectively) concentrations in the reactor decreased significantly with time for long term application of the ozonation treatment. Kinetic batch tests on unstressed sludge taken from Control SBR indicated that the different oxidant dosages (0.05, 0.07 and 0.37 g O(3)/gSS) and durations of the ozonation process (10, 20 and 30 minutes) used remarkably affected chemical oxygen demand (COD) and organic nitrogen fractioning. In particular, soluble and biodegradable fractions seemed to be higher at lower dosage and longer contact time.

Effect of ozonation on sludge reduction in a SBR plant

This paper provides new insights on the application of the ozonation process for the reduction of activated sludge production in a Sequencing Batch Reactor. The study was performed on two identical lab-scale SBRs plant, fed with domestic sewage: a fraction (1/3 of the working volume) of the activated sludge from one reactor (Exp SBR) was periodically subjected to ozonation for 30 minutes at 0.05 g O(3)/gSS and then recirculated before the beginning of the cycle; the other reactor was used as control and therefore managed at the same sludge retention time but without the application of ozonation. The effects of the recirculation of the ozonated sludge to the Exp SBR were evaluated in terms of biological nitrogen and carbon removal efficiencies, Mixed Liquor Volatile and Suspended Solids (MLSS and MLVSS, respectively) concentrations, effluent quality and sludge settleability. Besides, characterization of the ozonated sludge was carried out for different oxidant dosages (0.05, 0.07 and 0.37 g O(3)/gSS) and durations of the ozonation process (10, 20 and 30 minutes). The results show that at 0.05 g O(3)/gSS and 30 minutes contact time MLVSS as well as MLVSS/MLSS ratio do not change appreciably. Ozone dosage must be increased much further to obtain a relevant effect.

Molecular cloning of a gene from 'chromosome 3 specific' genomic library that encodes a novel CC-chemokine receptor like isotype

CC-chemokine receptors form a closely linked locus in the p21-23 region on the short arm of human chromosome 3. We report the isolation of a novel chemokine receptor like gene from a 'human chromosome 3 specific' genomic library, screened by cross-hybridization with cDNA probes derived from known chemokine receptors. The gene, CKR-SKG2 contains an open reading frame that encodes a 359-377 amino acid protein, with two potential in frame start codons. However, comparative Southern blot analysis of human, mouse and hamster genomic DNA, revealed that CKR-SKG2 is the hamster ortholog of a novel chemokine receptor. This presumably occurred because chromosome 3 used for construction of the genomic library were purified from a human-hamster somatic cell hybrid. Further studies are underway to identify and clone the putative human homolog of this novel chemokine receptor.