Effect of Discontinuing vs Continuing Angiotensin-Converting Enzyme Inhibitors and Angiotensin II Receptor Blockers on Days Alive and Out of the Hospital in Patients Admitted With COVID-19: A Randomized Clinical Trial.

Importance: It is unknown whether angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) have a positive, neutral, or negative effect on clinical outcomes in patients with coronavirus disease 2019 (COVID-19). Objective: To determine whether discontinuation compared with continuation of ACEIs or ARBs changed the number of days alive and out of the hospital through 30 days. Design, Setting, and Participants: A randomized clinical trial of 659 patients hospitalized in Brazil with mild to moderate COVID-19 who were taking ACEIs or ARBs prior to hospitalization (enrolled: April 9-June 26, 2020; final follow-up: July 26, 2020). Interventions: Discontinuation (n = 334) or continuation (n = 325) of ACEIs or ARBs. Main Outcomes and Measures: The primary outcome was the number of days alive and out of the hospital through 30 days. Secondary outcomes included death, cardiovascular death, and COVID-19 progression. Results: Among 659 patients, the median age was 55.1 years (interquartile range [IQR], 46.1-65.0 years), 14.7% were aged 70 years or older, 40.4% were women, and 100% completed the trial. The median time from symptom onset to hospital admission was 6 days (IQR, 4-9 days) and 27.2% of patients had an oxygen saturation of less than 94% of room air at baseline. In terms of clinical severity, 57.1% of patients were considered mild at hospital admission and 42.9% were considered moderate. There was no significant difference in the number of days alive and out of the hospital in patients in the discontinuation group (mean, 21.9 days [SD, 8 days]) vs patients in the continuation group (mean, 22.9 days [SD, 7.1 days]) and the mean ratio was 0.95 (95% CI, 0.90-1.01). There also was no statistically significant difference in death (2.7% for the discontinuation group vs 2.8% for the continuation group; odds ratio [OR], 0.97 [95% CI, 0.38-2.52]), cardiovascular death (0.6% vs 0.3%, respectively; OR, 1.95 [95% CI, 0.19-42.12]), or COVID-19 progression (38.3% vs 32.3%; OR, 1.30 [95% CI, 0.95-1.80]). The most common adverse events were respiratory failure requiring invasive mechanical ventilation (9.6% in the discontinuation group vs 7.7% in the continuation group), shock requiring vasopressors (8.4% vs 7.1%, respectively), acute myocardial infarction (7.5% vs 4.6%), new or worsening heart failure (4.2% vs 4.9%), and acute kidney failure requiring hemodialysis (3.3% vs 2.8%). Conclusions and Relevance: Among patients hospitalized with mild to moderate COVID-19 and who were taking ACEIs or ARBs before hospital admission, there was no significant difference in the mean number of days alive and out of the hospital for those assigned to discontinue vs continue these medications. These findings do not support routinely discontinuing ACEIs or ARBs among patients hospitalized with mild to moderate COVID-19 if there is an indication for treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT04364893.

Antitumor effect of free rhodium (II) citrate and rhodium (II) citrate-loaded maghemite nanoparticles on mice bearing breast cancer: a systemic toxicity assay.

Breast cancer is one of the most prevalent cancer types among women. The use of magnetic fluids for specific delivery of drugs represents an attractive platform for chemotherapy. In our previous studies, it was demonstrated that maghemite nanoparticles coated with rhodium (II) citrate (Magh-Rh2Cit) induced in vitro cytotoxicity and in vivo antitumor activity, followed by intratumoral administration in breast carcinoma cells. In this study, our aim was to follow intravenous treatment to evaluate the systemic antitumor activity and toxicity induced by these formulations in Balb/c mice bearing orthotopic 4T1 breast carcinoma. Female Balb/c mice were evaluated with regard to toxicity of intravenous treatments through analyses of hemogram, serum levels of alanine aminotransferase, iron, and creatinine and liver, kidney, and lung histology. The antitumor activity of rhodium (II) citrate (Rh2Cit), Magh-Rh2Cit, and maghemite nanoparticles coated with citrate (Magh-Cit), used as control, was evaluated by tumor volume reduction, histology, and morphometric analysis. Magh-Rh2Cit and Magh-Cit promoted a significant decrease in tumor area, and no experimental groups presented hematotoxic effects or increased levels of serum ALT and creatinine. This observation was corroborated by the histopathological examination of the liver and kidney of mice. Furthermore, the presence of nanoparticles was verified in lung tissue with no morphological changes, supporting the idea that our nanoformulations did not induce toxicity effects. No studies about the systemic action of rhodium (II) citrate-loaded maghemite nanoparticles have been carried out, making this report a suitable starting point for exploring the therapeutic potential of these compounds in treating breast cancer.

Antitumor effect and toxicity of free rhodium (II) citrate and rhodium (II) citrate-loaded maghemite nanoparticles in mice bearing breast cancer.

BACKGROUND: Magnetic fluids containing superparamagnetic iron oxide nanoparticles represent an attractive platform as nanocarriers in chemotherapy. Recently, we developed a formulation of maghemite nanoparticles coated with rhodium (II) citrate, which resulted in in vitro cytotoxicity enhanced up to 4.6 times when compared to free rhodium (II) citrate formulation on breast carcinoma cells. In this work, we evaluate the antitumor activity and toxicity induced by these formulations in Balb/c mice bearing orthotopic 4T1 breast carcinoma. METHODS: Mice were evaluated with regard to the treatments' toxicity through analyses of hemogram, serum levels of alanine aminotransferase, iron, and creatinine; DNA fragmentation and cell cycle of bone marrow cells; and liver, kidney and lung histology. In addition, the antitumor activity of rhodium (II) citrate and maghemite nanoparticles coated with rhodium (II) citrate was verified by tumor volume reduction, histology and immunohistochemistry. RESULTS: Regarding the treatments' toxicity, no experimental groups had alterations in levels of serum ALT or creatinine, and this suggestion was corroborated by the histopathologic examination of liver and kidney of mice. Moreover, DNA fragmentation frequency of bone marrow cells was lower than 15% in all experimental groups. On the other hand, the complexes rhodium (II) citrate-functionalized maghemite and free rhodium (II) citrate led to a marked growth inhibition of tumor and decrease in CD31 and Ki-67 staining. CONCLUSIONS: In summary, we demonstrated that both rhodium (II) citrate and maghemite nanoparticles coated with rhodium (II) citrate formulations exhibited antitumor effects against 4T1 metastatic breast cancer cell line following intratumoral administration. This antitumor effect was followed by inhibition of both cell proliferation and microvascularization and by tumor tissue injury characterized as necrosis and fibrosis. Remarkably, this is the first published report demonstrating the therapeutic efficacy of maghemite nanoparticles coated with rhodium (II) citrate. This treatment prolonged the survival period of treated mice without inducing apparent systemic toxicity, which strengthens its use for future breast cancer therapeutic applications.

Free Rhodium (II) citrate and rhodium (II) citrate magnetic carriers as potential strategies for breast cancer therapy.

BACKGROUND: Rhodium (II) citrate (Rh(2)(H(2)cit)(4)) has significant antitumor, cytotoxic, and cytostatic activity on Ehrlich ascite tumor. Although toxic to normal cells, its lower toxicity when compared to carboxylate analogues of rhodium (II) indicates (Rh(2)(H(2)cit)(4)) as a promising agent for chemotherapy. Nevertheless, few studies have been performed to explore this potential. Superparamagnetic particles of iron oxide (SPIOs) represent an attractive platform as carriers in drug delivery systems (DDS) because they can present greater specificity to tumor cells than normal cells. Thus, the association between Rh(2)(H(2)cit)(4) and SPIOs can represent a strategy to enhance the former's therapeutic action. In this work, we report the cytotoxicity of free rhodium (II) citrate (Rh(2)(H(2)cit)(4)) and rhodium (II) citrate-loaded maghemite nanoparticles or magnetoliposomes, used as drug delivery systems, on both normal and carcinoma breast cell cultures. RESULTS: Treatment with free Rh(2)(H(2)cit)(4) induced cytotoxicity that was dependent on dose, time, and cell line. The IC(50) values showed that this effect was more intense on breast normal cells (MCF-10A) than on breast carcinoma cells (MCF-7 and 4T1). However, the treatment with 50 µM Rh(2)(H(2)cit)(4)-loaded maghemite nanoparticles (Mag(h)-Rh(2)(H(2)cit)(4)) and Rh(2)(H(2)cit)(4)-loaded magnetoliposomes (Lip-Magh-Rh(2)(H(2)cit)(4)) induced a higher cytotoxicity on MCF-7 and 4T1 than on MCF-10A (p < 0.05). These treatments enhanced cytotoxicity up to 4.6 times. These cytotoxic effects, induced by free Rh(2)(H(2)cit)(4), were evidenced by morphological alterations such as nuclear fragmentation, membrane blebbing and phosphatidylserine exposure, reduction of actin filaments, mitochondrial condensation and an increase in number of vacuoles, suggesting that Rh(2)(H(2)cit)(4) induces cell death by apoptosis. CONCLUSIONS: The treatment with rhodium (II) citrate-loaded maghemite nanoparticles and magnetoliposomes induced more specific cytotoxicity on breast carcinoma cells than on breast normal cells, which is the opposite of the results observed with free Rh(2)(H(2)cit)(4) treatment. Thus, magnetic nanoparticles represent an attractive platform as carriers in Rh(2)(H(2)cit)(4) delivery systems, since they can act preferentially in tumor cells. Therefore, these nanopaticulate systems may be explored as a potential tool for chemotherapy drug development.

Reevaluation of the 2-deoxyribose assay for determination of free radical formation.

BACKGROUND: The 2-deoxyribose (2-DR) degradation assay is a widely used test for determining anti/pro-oxidant properties of molecules and plant extracts. Most reports use reaction blanks omitting 2-DR or thiobarbituric acid (TBA). However, when studying Fe(II)-mediated reactions, we verified that these blanks are not appropriate. Fe(III)--a product of these reactions--causes a relevant artifact in the assay, where 2-DR is oxidized by Fe(III). METHOD: 2-DR degradation was determined at 532 nm as TBA-reactive substances. RESULTS AND CONCLUSION: HPLC determinations indicated that Fe(III) added after or before TBA generates considerable amounts of malondialdehyde (2-DR degradation product) in comparison with assays employing Fenton reagents or Fe(II) autoxidation. Addition of catalase and thiourea has no effect on Fe(III)-induced 2-DR degradation indicating lack of ROS involvement. This Fe(III)-mediated 2-DR damage is dependent on iron and 2-DR concentrations, but not on H2O2, buffer composition or iron-chelators. Depending on the assay conditions Fe(III)-interference accounts for 20% to 90% of 2-DR degradation mediated by Fe(II). SIGNIFICANCE: A new reaction blank is proposed herein-based on the use of Fe(III)-for the assay. The lack of such correction has caused the underestimation of antioxidant capacity of various compounds in many studies in the last 2 decades.

Comparação da infecção por protozoários em chinchila (Chinchilla lanigera) de uma criação comercial do município de Viamão-RS, Brasil, e de chinchilas no seu habitat natural, Chile / Comparison of protozoan infection between chinchillas chinchilla lanigera) from a commercial breeding facility in southern Brazil and chinchillas from a natural reserve in Chile

Chinchilla lanígera é um roedor proveniente do Chile e sua criação é com fins comerciais. As doencas parasitarias, principalmente giardíase podem causar problemas clínicos e sanitarios, causando perdas produtivas e económicas. Foram colhidas amostras de fezes de 220 chinchilas de urna criação comercial no sul do Brasil e 35 amostras de chinchilas da Reserva Nacional las Chinchillas no Chile, e submetidas ão método de Faust e colaboradores. O total de amostras positivas para cistos de Giardia sp. foi de 31,37 por cento (80/255); da criação comercial foi de 36,36 por cento(80/220). O número de amostras que apresentaram mais de 5 cistos/campo foi 4,55 por cento(10/220). Todas as amostras dos animáis da Reserva foram negativas. Não houve associação entre a positividade e a faixa etária dos animais analisados.

Chinchilla lanígera is a rodent native to Chile which is bred for commercial purposes. Parasitic diseases, mainly giardiasis, may cause clinical and sanitary problems and lead to production and economic losses. Fecal samples were collected from 220 chinchillas pertaining to a commercial breeding facility in southern Brazil and from 35 chinchillas from Las Chinchillas National Reserve in Chile. All samples were analyzed using the method proposed by Faust et al. Positive samples for Giardia cysts amounted to 31.37 percent (80/255); 36.36 percent (80/220) was recovered from the commercial breeding facility. The rate of samples with over 5 cysts/field was equivalent to 4.55 percent (10/220). All of the samples collected from the National Reserve were negative for Giardia sp. No association was found between positive rates for Giardia sp. and the age of chinchillas.

Pyridoxal isonicotinoyl hydrazone inhibits iron-induced ascorbate oxidation and ascorbyl radical formation.

Previous work from our laboratory demonstrated that pyridoxal isonicotinoyl hydrazone (PIH) has in vitro antioxidant activity against iron plus ascorbate-induced 2-deoxyribose degradation due to its ability to chelate iron; the resulting Fe(III)-PIH(2) complex is supposedly unable to catalyze oxyradical formation. A putative step in the antioxidant action of PIH is the inhibition of Fe(III)-mediated ascorbate oxidation, which yields the Fenton reagent Fe(II) [Biochim. Biophys. Acta 1523 (2000) 154]. In this work, we demonstrate that PIH inhibits Fe(III)-EDTA-mediated ascorbate oxidation (measured at 265 nm) and the formation of ascorbyl radical (in electron paramagnetic resonance (EPR) studies). The efficiency of PIH against ascorbate oxidation, ascorbyl radical formation and 2-deoxyribose degradation was dose dependent and directly proportional to the period of preincubation of PIH with Fe(III)-EDTA. The efficiency of PIH in inhibiting ascorbate oxidation and ascorbyl radical formation was also inversely proportional to the Fe(III)-EDTA concentration in the media. When EDTA was replaced by the weaker iron ligand nitrilotriacetic acid (NTA), PIH was much more effective in preventing ascorbate oxidation, ascorbyl radical formation and 2-deoxyribose degradation. Moreover, the replacement of EDTA with citrate, a physiological chelator with a low affinity for iron, also resulted in PIH having a higher efficiency in inhibiting iron-mediated ascorbate oxidation and 2-deoxyribose degradation. These results demonstrate that PIH removes iron from EDTA (or from either NTA or citrate), forming an iron-PIH complex that cannot induce ascorbate oxidation effectively, thus inhibiting iron-mediated oxyradical formation. These results are of pharmacological relevance because PIH has been considered for experimental chelating therapy in iron-overload diseases.