Zinc Essentiality, Toxicity, and Its Bacterial Bioremediation: A Comprehensive Insight.

Zinc (Zn) is one of the most abundantly found heavy metals in the Earth's crust and is reported to be an essential trace metal required for the growth of living beings, with it being a cofactor of major proteins, and mediating the regulation of several immunomodulatory functions. However, its essentiality also runs parallel to its toxicity, which is induced through various anthropogenic sources, constant exposure to polluted sites, and other natural phenomena. The bioavailability of Zn is attributable to various vegetables, beef, and dairy products, which are a good source of Zn for safe consumption by humans. However, conditions of Zn toxicity can also occur through the overdosage of Zn supplements, which is increasing at an alarming rate attributing to lack of awareness. Though Zn toxicity in humans is a treatable and non-life-threatening condition, several symptoms cause distress to human activities and lifestyle, including fever, breathing difficulty, nausea, chest pain, and cough. In the environment, Zn is generally found in soil and water bodies, where it is introduced through the action of weathering, and release of industrial effluents, respectively. Excessive levels of Zn in these sources can alter soil and aquatic microbial diversity, and can thus affect the bioavailability and absorption of other metals as well. Several Gram-positive and -negative species, such as Bacillus sp., Staphylococcus sp., Streptococcus sp., and Escherichia coli, Pseudomonas sp., Klebsiella sp., and Enterobacter sp., respectively, have been reported to be promising agents of Zn bioremediation. This review intends to present an overview of Zn and its properties, uses, bioavailability, toxicity, as well as the major mechanisms involved in its bioremediation from polluted soil and wastewaters.

The anti-spasmodic effect of peppermint oil during colonoscopy: a systematic review and meta-analysis.

INTRODUCTION: Multiple pharmacological agents have been studied in literature with antispasmodic effect during colonoscopy. Peppermint oil, with its relaxing effect on colon has demonstrated varying results. We therefore conducted a systematic review and meta-analysis of the available literature to evaluate its role during colonoscopy. EVIDENCE ACQUISITION: Literature search of the following databases was undertaken: PubMed\Medline, Embase, Cochrane, Web of Science, and CINAHL. Outcomes that were evaluated included incidence of any spasticity, severe spasticity, and peristalsis during examination. Adenoma detection rate (ADR) was evaluated as a quality outcome metric. Risk ratios (RR), risk difference (RD) and mean difference (MD) were calculated using the DerSimonian-Laird method and random effects where applicable. EVIDENCE SYNTHESIS: Overall, six studies (with one abstract) were included in this review. Peppermint oil resulted in overall lower incidence for spasticity (RD: -0.39, P=0.02), severe spasticity (RD: -0.15, P=0.04), and peristalsis (-0.27, P≤0.001) during colonoscopy examination. An improved ADR (RR: 1.31, P=0.01) was also noted, however only two studies evaluated this effect. CONCLUSIONS: Peppermint oil resulted in relaxation of colon during colonoscopy with decrease incidence of spasticity, severe spasticity, peristalsis and improved ADR. These results are encouraging however results are limited due to significant heterogeneity found in the outcomes. Larger studies with standardized dosing are needed to evaluate this effect. Furthermore, studies evaluating additional colonoscopy outcomes such as polyp detection rate, advanced adenoma detection rate, and serrated adenoma detection rate are needed.

Treatment of apixaban- and rivaroxaban-associated major bleeding using 4-factor prothrombin complex concentrate.

There is limited clinical experience with the use of coagulation concentrates to reverse the effect of direct oral anticoagulants. We assess the achievement of effective clinical hemostasis with the use of 4-factor prothrombin complex concentrate (PCC) in patients on apixaban or rivaroxaban presenting with major bleeding. A retrospective chart review was conducted at a tertiary referral medical center in the USA. We assess the achievement of clinical hemostasis using 4-factor PCC in patients on chronic apixaban or rivaroxaban therapy presenting with major bleeding. Clinical hemostasis was assessed by the International Society of Thrombosis and Hemostasis Scientific and Standardization Subcommittee criteria. A total of 29 patients are included in the study. The most common site of bleeding was intracranial hemorrhage (ICH) (72.4%), followed by gastrointestinal bleed (13.8%). Clinical hemostasis was achieved in 21 (72.4%) patients. Patients who did not achieve clinical hemostasis (27.6%) suffered from ICH, and all of them died during hospitalization except for two patients who were discharged with neurologic deterioration. One patient developed multiple brain infarctions after receiving 4-factor PCC. Sixteen patients (55.2%) were receiving concomitant medications that interact with apixaban and rivaroxaban and increase the risk of bleeding. Four-factor PCC appears to be effective in achieving clinical hemostasis in patients on apixaban or rivaroxaban presenting with major bleeding. It may be an alternative to patients who need anticoagulation reversal if the specific antidote, andexanet alfa, is not available.

Safety and effectiveness of 100 mg/kg/day deferiprone in patients with thalassemia major: a two-year study.

Deferiprone at a dose of 75 mg/kg/day is not sufficiently effective to maintain iron stores at a level which has been considered safe in all patients with iron overload. Our main aim was to determine the safety of long-term therapy with high-dose (100 mg/kg/day) deferiprone. A secondary aim was to determine the efficacy of this high dose. Twelve thalassemia major patients received deferiprone at a dose of 100 mg/kg/day over 2 years. Transient aspartate aminotransferase increase (8 patients), gastrointestinal discomfort (3 patients) and arthralgia (2 patients) were the most commonly reported side effects. None of the patients discontinued therapy. The mean serum ferritin level fell from 3,901 +/- 3,618 to 1,790 +/- 2,205 microg/l after 2 years (p < 0.05). Five of the 12 patients continued to receive deferiprone for an additional 3 years. No new side effects were encountered. The mean serum ferritin level in this subgroup was initially 2,510 +/- 332 microg/l and dropped to 1,511 +/- 664 microg/l after 5 years (p < 0.05). Liver iron levels at the end of the 2-year study ranged from 1.0 to 30.9 mg/g dry weight, 3 of the patients having levels above 15 mg/g.

Comparison between desferrioxamine and combined therapy with desferrioxamine and deferiprone in iron overloaded thalassaemia patients.

Desferrioxamine (DFX) alone (40-50 mg/kg/d s.c. over 8-12 h, five times weekly) was compared with combined DFX twice weekly and deferiprone (75 mg/kg/d) over 12 months in previously poorly chelated thalassaemia patients. Serum ferritin fell from 5506 +/- 635 microg/l (mean +/- SEM) to 3998 +/- 604 microg/l (P < 0.001; n = 14) in the DFX group and from 4153 +/- 517 microg/l to 2805 +/- 327 microg/l in the combined group (P < 0.01; n = 11). Deferiprone plus DFX produced a greater mean urine iron excretion (1.01 mg/kg/24 h) than iron intake from blood transfusion in each patient. Main side-effects were skin reactions (DFX alone), nausea and arthralgia (combined therapy). As chelation therapy, the combined protocol was as effective as DFX five times weekly.

Comparison between deferoxamine and deferiprone (L1) in iron-loaded thalassemia patients.

INTRODUCTION: Iron-chelating therapy with deferoxamine in patients with thalassemia major has dramatically improved the prognosis of this disease. However, the limitations of this treatment have stimulated the design of alternative orally active iron chelators. OBJECTIVE: To compare the effectiveness and safety of, and compliance with, oral deferiprone (L1), and deferoxamine, in thalassemia major patients. METHODS: All patients were followed up in one center in Lebanon. Sixteen patients were on L1 (75 mg/kg/d), and 40 patients on subcutaneous deferoxamine (20-50 mg/kg/d). Serum ferritin level, urinary iron excretion (UIE) and side effects were monitored over a two year period. RESULTS: Patients on L1 had an initial serum ferritin concentration of 3663+/-566 microg/l (mean+/-SEM), that dropped to 2599+/-314 at 6 months (p<0.02; paired t-test), and stabilised at that level over the 24 months follow up. Patients on deferoxamine had an initial mean serum ferritin concentration of 3480+/-417 (NS compared to the L1 group), which dropped gradually to 3143+/-417 (p<0.05) and 2819+/-292 (p<0.02) at 6 and 24 months, respectively. The most common adverse reactions associated with L1 were arthralgia and nausea, but they did not necessitate stopping the drug. CONCLUSION: L1 had comparable efficacy as deferoxamine with minimal side effects and better compliance. Provided long term side effects are not encountered, L1 seems to be a valuable alternative iron chelator for patients unable or unwilling to use deferoxamine effectively.