Is it safe to prescribe ascorbic acid for urinary acidification in stone-forming patients with alkaline urine?

Current Viewpoint on Female Urogenital Microbiome-The Cause or the Consequence?

An increasing amount of evidence implies that native microbiota is a constituent part of a healthy urinary tract (UT), making it an ecosystem on its own. What is still not clear is whether the origin of the urinary microbial community is the indirect consequence of the more abundant gut microbiota or a more distinct separation exists between these two systems. Another area of uncertainty is the existence of a link between the shifts in UT microbial composition and both the onset and persistence of cystitis symptoms. Cystitis is one of the most common reasons for antimicrobial drugs prescriptions in primary and secondary care and an important contributor to the problem of antimicrobial resistance. Despite this fact, we still have trouble distinguishing whether the primary cause of the majority of cystitis cases is a single pathogen overgrowth or a systemic disorder affecting the entire urinary microbiota. There is an increasing trend in studies monitoring changes and dynamics of UT microbiota, but this field of research is still in its infancy. Using NGS and bioinformatics, it is possible to obtain microbiota taxonomic profiles directly from urine samples, which can provide a window into microbial diversity (or the lack of) underlying each patient's cystitis symptoms. However, while microbiota refers to the living collection of microorganisms, an interchangeably used term microbiome referring to the genetic material of the microbiota is more often used in conjunction with sequencing data. It is this vast amount of sequences, which are truly "Big Data", that allow us to create models that describe interactions between different species contributing to an UT ecosystem, when coupled with machine-learning techniques. Although in a simplified predator-prey form these multi-species interaction models have the potential to further validate or disprove current beliefs; whether it is the presence or the absence of particular key players in a UT microbial ecosystem, the exact cause or consequence of the otherwise unknown etiology in the majority of cystitis cases. These insights might prove to be vital in our ongoing struggle against pathogen resistance and offer us new and promising clinical markers.

High Dietary Cation and Anion Difference and High-Dose Ascorbic Acid Modify Acid–Base and Antioxidant Balance in Dairy Goats Fed under Tropical Conditions

High ambient temperature (HTa) causes acid–base imbalance and systemic oxidative stress, and this may indirectly affect the mammary gland. Furthermore, HTa induces intracellular oxidative stress, which has been proposed to affect cell metabolism directly. We previously showed in dairy goats that the negative effect of HTa was compromised by enhancing heat dissipation during a high dietary cation and anion difference (DCAD) regimen. Moreover, high-dose vitamin C or ascorbic acid (AA) supplements have been used to manage oxidative stress in ruminants. The present study hypothesized that high DCAD and AA supplements that could alleviate the HTa effect would influence the milk synthesis pathway and mammary gland function. The results showed that goats fed with high DCAD had higher blood pH than control goats in the 4th week. The high dose of AA supplement decreases urine pH in the 8th week. The percent reduction of urine pH from the AA supplement was significant in the DCAD group. The high-dose AA supplement decreased plasma glutathione peroxidase activity and malonaldehyde. This effect was enhanced by a high DCAD supplement. In addition, supplementation with AA increased milk protein and citrate and decreased milk FFA. These alterations indicate the intracellular biochemical pathway of energy metabolism and milk synthesis. It can be concluded that a high DCAD regimen and AA supplement in dairy goats fed under HTa could influence the milk synthesis pathway. The evidence suggests that HTa decreases mammary gland function by modification of acid–base homeostasis and oxidative stress.

Combined Application of Aminoglycosides and Ascorbic Acid in the Elimination of Proteus mirabilis Rods Responsible for Causing Catheter-Associated Urinary Tract Infections (CAUTIs)-A Molecular Approach

Proteus mirabilis is a common cause of catheter-associated urinary tract infections (CAUTIs). In this study, we verified the effectiveness of amikacin or gentamicin and ascorbic acid (AA) co-therapy in eliminating uropathogenic cells, as well as searched for the molecular basis of AA activity by applying chromatographic and fluorescent techniques. Under simulated physiological conditions, a combined activity of the antibiotic and AA supported the growth (threefold) of the P. mirabilis C12 strain, but reduced catheter colonization (≤30%) in comparison to the drug monotherapy. Slight modifications in the phospholipid and fatty acid profiles, as well as limited (≤62%) 2',7'-dichlorofluorescein fluorescence, corresponding to the hydroxyl radical level, allowed for the exclusion of the hypothesis that the anti-biofilm effect of AA was related to membrane perturbations of the C12 strain. However, the reduced (≤20%) fluorescence intensity of propidium iodide, as a result of a decrease in membrane permeability, may be evidence of P. mirabilis cell defense against AA activity. Quantitative analyses of ascorbic acid over time with a simultaneous measurement of the pH values proved that AA can be an effective urine acidifier, provided that it is devoid of the presence of urease-positive cells. Therefore, it could be useful in a prevention of recurrent CAUTIs, rather than in their treatment.

Womens' self-management skills for prevention and treatment of recurring urinary tract infection

BACKGROUND

The guideline on urinary tract infections (UTI) of the Dutch College of General Practitioners provides recommendations on patient-initiated treatment and prevention of recurring UTI.

AIM

To study familiarity with self-management skills for prevention of recurring UTI amongst adult women.

DESIGN AND SETTINGS

An online questionnaire was developed, based on the UTI guideline and interviews with women having recurring UTI. Pharmacists in a postgraduate education programme (N = 76) aimed to invite 10 adult women with a recurring UTI prescription to complete the questionnaire. Women were asked for informed consent to link medication record data to questionnaire data.

METHOD

We calculated proportions of the scores for self-management skills and analysed differences between age groups with chi-square test.

RESULTS

Complete questionnaires were available for 719 women (mean age 55.1 ± 18.5 years). The proportions of women 18-50 years and women 51 years or older were 36.4% and 63.6%, respectively. Education levels of women 18-50 years were significantly higher than those of women 51 years and older. Before consulting a general practitioner (GP) for symptoms, 32.1% of all women increased fluid intake; additionally, 15.0% used analgesics and increased fluid intake. Of all women, 33.9% searched internet for information on self-management and 18% occasionally received a prescription for patient-initiated treatment, half of these prescriptions for use during vacation. Cranberry was used by 47%, d-mannose by 5% and vitamin C by 29% of all women. Awareness of different preventive behavioural measures (eg, fluid intake, washing without soap and emptying bladder after sexual intercourse) varied between 20% and 90%.

CONCLUSION

Almost half of all women applied self-management (increased fluid intake, analgesics) before consulting a GP for recurring UTI. Awareness of preventive behavioural measures for recurring UTI varied considerably. Thus, education of women about the use of analgesics and behavioural measures deserves attention.

Vitamin C and kidney transplantation: Nutritional status, potential efficacy, safety, and interactions

BACKGROUND AND AIM

There are several observational and interventional studies regarding the advantages of sufficient serum levels of vitamin C and the evaluation of the effects of vitamin C supplementation post kidney transplantation. These studies have been put together to investigate the role of vitamin C post-kidney transplantation and make suggestions for designing future studies based on the use of vitamin C supplements or nutritional interventions among these patients.

METHODS

This narrative review was done by searching in the Embase, PubMed, and SCOPUS databases.

RESULTS

The results are presented in several sections as follows; nutritional status, potential protective effects, safety concerns, and medications/laboratory tests interactions of vitamin C.

CONCLUSIONS

Kidney transplant recipients are prone to vitamin C deficiency, which is related to higher mortality based on several long-term observational studies. Vitamin C supplementation improves endothelial function and creatinine clearance. Vitamin C is considered as a safe supplement, however, side effects such as kidney stones, pro-oxidant effect, hemolysis in patients with glucose-6-phosphate dehydrogenase deficiency, impact on lymphocytic activity, acid-base disturbance, and increased sodium load following its administration have been reported. Interaction of vitamin C and cyclosporine is the most important interaction with post-renal transplant medications. Vitamin C also interferes with creatinine assay using Jaffe and enzymatic methods.

Dynamic thiol/disulfide homeostasis as a novel indicator of oxidative stress in patients with urolithiasis

Purpose

A dynamic thiol/disulfide balance is pivotal in organizing anti-oxidant defense, detoxification, apoptosis, and enzyme activities, as well as transcription and cellular signal-transfer mechanisms. The connection between urolithiasis and oxidant/antioxidant status, which can be assessed through thiol-disulfide homeostasis (TDH), has not yet been examined. In this study, we evaluated the effects of TDH on the formation, size, and location of stones by examining the associations between TDH parameters and urolithiasis.

Materials and Methods

Patients with urolithiasis and healthy controls were recruited. The patients were divided into subgroups in terms of stone size (>15 mm or ≤15 mm) and stone location (nephrolithiasis or ureterolithiasis). TDH parameters were measured using a novel automatic and spectrophotometric method and compared statistically.

Results

TDH parameters were different between the urolithiasis and control groups. TDH tended towards the disulfide side in the urolithiasis group. Stone size increased an average 0.14 mm with a 1 µmol/L increase in disulfide level and decreased an average 0.058 mm with a 1 µmol/L increase in native thiol level. Disulfide and native thiol levels were found to be different across patients with stone size >15 mm, ≤15 mm, and controls (p<0.001 and p<0.001, respectively). However, the nephrolithiasis and ureterolithiasis groups were similar in respect of TDH parameters.

Conclusions

In this study, it was found that patients with urolithiasis displayed oxidative stress characterized by a TDH tendency towards the disulfide side, and an inadequate antioxidant response identified by a lower level of native thiol as compared with healthy controls.