Body composition and metabolic consequences of antibiotics most frequently administered to newborns in intensive care units: an experimental study in healthy newborn rats.

Introduction: The increasing overuse of antibiotics in recent years has led to antibiotics being the most prescribed drugs for pediatric patients, and 72% of patients in the neonatal intensive care unit are treated with antibiotics. One effect of antibiotic use is the alteration of the microbiota, which is associated with metabolic disorders, including obesity. Methods: This experimental study in newborn rats compared the administration of ampicillin/meropenem (Access/Watch groups) at 100/10 µg/g every 12 h, cefotaxime 200 µg/g every 24 h (Watch group), and amikacin 15 µg/g every 24 h (Access group) versus saline solution as the control. Each antibiotic was adjusted to the required dosages based on weight, and the doses were administered intraperitoneally daily for 5 days to 10-14 newborn male rats per group. A comparison of the morphometric and biochemical parameters registered on day 28 was performed using ANOVA. Results: Amikacin had the largest effect on morphometric measurements, and low-density lipoprotein cholesterol, while cefotaxime had the largest effect on glucose and triglycerides, whereas ampicillin/meropenem produced the weakest effect on the measured parameters. Discussion: The administration of antibiotics in the neonatal stage can affect the body composition of rats as well as the lipid and carbohydrate serum levels. Future studies should evaluate the toxicity of antibiotics in immature neonatal organs and could help to improve therapeutic decisions and prevent the unjustified use of antibiotics in newborns, thereby reducing metabolic consequences.

Regional moderate hyperthermia for mild-to-moderate COVID-19 (TherMoCoV study): a randomized controlled trial.

Background: To prevent COVID-19 progression, low-cost alternatives that are available to all patients are needed. Diverse forms of thermotherapy have been proposed to prevent progression to severe/critical COVID-19. Objective: The aim of this study is to evaluate the efficacy and safety of local thermotherapy to prevent disease progression in hospitalized adult patients with mild-to-moderate COVID-19. Methods: A multicenter, open-label, parallel-group, randomized, adaptive trial is used to evaluate the efficacy and safety of local thermotherapy to prevent disease progression in hospitalized adult patients with mild-to-moderate COVID-19. Eligible hospitalized adult patients with symptoms of COVID-19 with ≤5 days from symptom onset, meeting criteria for mild or moderate COVID-19, were randomly assigned to the intervention consisting of local thermotherapy via an electric heat pad in the thorax (target temperature range 39.5­42°C) continuously for 90 min, twice daily, for 5 days, or standard care. The main outcome was the proportion of patients who progressed to severe-to-critical COVID-19 or death. Patients were randomized in a 1:1 ratio through a centralized computer-generated sequence of minimization with a random component of 20%. Participants and medical staff were not blinded to the intervention. Results: One-hundred and five participants (thermotherapy n = 54, control n = 51) with a median age of 53 (IQR: 41­64) years were included for analysis after the early cessation of recruitment due to the closure of all temporal COVID-19 units (target sample size = 274). The primary outcome of disease progression occurred in 31.4% (16/51) of patients in the control group vs. 25.9% (14/54) of those receiving thermotherapy (risk difference = 5.5%; 95%CI: −11.8­22.7, p = 0.54). Thermotherapy was well tolerated with a median total duration of thermotherapy of 900 (IQR: 877.5­900) min. Seven (13.7%) patients in the control group and seven (12.9%) in the thermotherapy group had at least one AE (p = 0.9), none of which were causally attributed to the intervention. No statistically significant differences in serum cytokines (IL-1ß, IL-6, IL-8, IL-10, IL-17, and IFN-γ) were observed between day 5 and baseline among groups. Conclusion: Local thermotherapy was safe and well-tolerated. A non-statistically significant lower proportion of patients who experienced disease progression was found in the thermotherapy group compared to standard care. Local thermotherapy could be further studied as a strategy to prevent disease progression in ambulatory settings.Clinical Trial registration: www.clinicaltrials.gov, identifier: NCT04363541.

Bases for a treatment of cutaneous leishmaniasis with moderate hyperthermia.

INTRODUCTION: Regional hyperthermia at between 38 and 39.5 °C has been used to treat inflammatory processes and, occasionally, skin infections. In areas where leishmaniasis is endemic, hot compresses are applied as anti-parasitic treatment. OBJECTIVE: To identify the bases of leishmaniasis thermal treatment in order to properly regulate it. METHODS: In vitro-cultured Leishmania mexicana parasites were incubated for variable periods at 37 and then at 25 °C. The parasites were then stained with Annexin V-FITC to detect apoptosis induction and with propidium iodide for viability. Post-treatment growth curves and cell cycle identification with anti-cyclin antibodies were performed. RESULTS: After 30 minutes of exposure to a temperature of 37 °C, a variable proportion of parasites lost their characteristic oval shape and became spherical, without refringence and with condensed nuclei, with these changes suggesting apoptosis, which was confirmed by Annexin V-FITC staining. The number of parasites that underwent apoptosis was proportional to exposure time. Parasites in which apoptosis was observed were stained with anti-cyclin antibodies. CONCLUSIONS: Constant, regulated and physiological elevation of temperature for more than 30 minutes induces apoptosis of in vitro-cultured L. mexicana parasites when they are in an active phase of the cell cycle.

INTRODUCCIÓN: La hipertermia regional entre 38 y 39.5 °C ha sido empleada para tratar procesos inflamatorios y, ocasionalmente, infecciones cutáneas. En zonas endémicas de leishmaniosis se aplican compresas calientes como tratamiento antiparasitario. OBJETIVO: Conocer las bases del tratamiento térmico de la leishmaniosis para regularlo adecuadamente. MÉTODOS: Parásitos Leishmania mexicana cultivados in vitro fueron incubados por periodos variables de 37 °C y después a 25 °C.. Los parásitos se tiñeron con anexina V-FITC y yoduro de propidio para detectar inducción de apoptosis y su viabilidad. Se realizaron curvas de crecimiento postratamiento e identificación del ciclo celular con anticuerpos anticiclinas. RESULTADOS: Después de 30 minutos de exposición a una temperatura de 37 °C, un porcentaje variable de parásitos perdieron su característica forma ovalada y se tornaron esféricos, sin refringencia y con núcleos condensados, cambios que sugirieron apoptosis, la cual fue confirmada mediante tinción con anexina V-FITC. La cantidad de parásitos en proceso de apoptosis fue proporcional al tiempo de exposición. Los parásitos en los que se observó apoptosis se tiñeron con anticuerpos anticiclinas. CONCLUSIONES: La elevación constante, regulada y fisiológica de la temperatura por más de 30 minutos induce apoptosis de parásitos Leishmania mexicana cultivados in vitro, cuando se encuentran en fase activa en el ciclo celular.

Bases para un tratamiento con hipertermia moderada en leishmaniosis cutánea / Bases for a treatment of cutaneous leishmaniasis with moderate hyperthermia

Resumen Introducción: La hipertermia regional entre 38 y 39.5 °C ha sido empleada para tratar procesos inflamatorios y, ocasionalmente, infecciones cutáneas. En zonas endémicas de leishmaniosis se aplican compresas calientes como tratamiento antiparasitario. Objetivo: Conocer las bases del tratamiento térmico de la leishmaniosis para regularlo adecuadamente. Métodos: Parásitos Leishmania mexicana cultivados in vitro fueron incubados por periodos variables de 37 °C y después a 25 °C.. Los parásitos se tiñeron con anexina V-FITC y yoduro de propidio para detectar inducción de apoptosis y su viabilidad. Se realizaron curvas de crecimiento postratamiento e identificación del ciclo celular con anticuerpos anticiclinas. Resultados: Después de 30 minutos de exposición a una temperatura de 37 °C, un porcentaje variable de parásitos perdieron su característica forma ovalada y se tornaron esféricos, sin refringencia y con núcleos condensados, cambios que sugirieron apoptosis, la cual fue confirmada mediante tinción con anexina V-FITC. La cantidad de parásitos en proceso de apoptosis fue proporcional al tiempo de exposición. Los parásitos en los que se observó apoptosis se tiñeron con anticuerpos anticiclinas. Conclusiones: La elevación constante, regulada y fisiológica de la temperatura por más de 30 minutos induce apoptosis de parásitos Leishmania mexicana cultivados in vitro, cuando se encuentran en fase activa en el ciclo celular.

Abstract Introduction: Regional hyperthermia at between 38 and 39.5 °C has been used to treat inflammatory processes and, occasionally, skin infections. In areas where leishmaniasis is endemic, hot compresses are applied as anti-parasitic treatment. Objective: To identify the bases of leishmaniasis thermal treatment in order to properly regulate it. Methods: In vitro-cultured Leishmania mexicana parasites were incubated for variable periods at 37 and then, to 25 °C. The parasites were then stained with Annexin V-FITC to detect apoptosis induction and with propidium iodide for viability. Post-treatment growth curves and cell cycle identification with anti-cyclin antibodies were performed. Results: After 30 minutes of exposure to a temperature of 37 °C, a variable proportion of parasites lost their characteristic oval shape and became spherical, without refringence and with condensed nuclei, with these changes suggesting apoptosis, which was confirmed by Annexin V-FITC staining. The number of parasites that underwent apoptosis was proportional to exposure time. Parasites in which apoptosis was observed were stained with anti-cyclin antibodies. Conclusions: Constant, regulated and physiological elevation of temperature for more than 30 minutes induces apoptosis of in vitro-cultured L. mexicana parasites when they are in an active phase of the cell cycle.

Breastfeeding and COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic has affected all dimensions of health care, including exclusive breastfeeding assurance and its promotion. The risk of contagion and the consequences of the pandemic have raised concerns among future mothers or in those who are already breastfeeding due to the risk of possible transmission of the virus through breast milk, although active severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has not yet been detected in breast milk. The fear of contagion has favored mother-child isolation policies. So far, there is no evidence of vertical transmission, and the risk of horizontal transmission in the infant is similar to that of the general population. In infants with COVID-19, breastfeeding can even favorably change the clinical course of the disease.

La pandemia de enfermedad por coronavirus 2019 (COVID-19) ha afectado a todas las dimensiones de la atención en salud, entre ellas el aseguramiento de la lactancia materna exclusiva y su promoción. El riesgo de contagio y las consecuencias de la pandemia han provocado preocupación entre las futuras madres o las que se ya encuentran lactando debido al riesgo de una posible transmisión del virus a través de la leche materna. Aunque aún no se ha detectado el coronavirus 2 del síndrome respiratorio agudo grave (SARS-CoV-2) activo en la leche materna. El miedo al contagio ha favorecido las políticas de aislamiento madre-hijo. Hasta el momento no existe evidencia de transmisión vertical y el riesgo de transmisión horizontal en el lactante es similar al de la población general. En lactantes con COVID-19 la lactancia materna incluso puede cambiar favorablemente el curso clínico de la enfermedad.

Lactancia materna y COVID-19 / Breastfeeding and COVID-19

Resumen La pandemia de enfermedad por coronavirus 2019 (COVID-19) ha afectado a todas las dimensiones de la atención en salud, entre ellas el aseguramiento de la lactancia materna exclusiva y su promoción. El riesgo de contagio y las consecuencias de la pandemia han provocado preocupación entre las futuras madres o las que se ya encuentran lactando debido al riesgo de una posible transmisión del virus a través de la leche materna. Aunque aún no se ha detectado el coronavirus 2 del síndrome respiratorio agudo grave (SARS-CoV-2) activo en la leche materna. El miedo al contagio ha favorecido las políticas de aislamiento madre-hijo. Hasta el momento no existe evidencia de transmisión vertical y el riesgo de transmisión horizontal en el lactante es similar al de la población general. En lactantes con COVID-19 la lactancia materna incluso puede cambiar favorablemente el curso clínico de la enfermedad.

Abstract The COVID-19 pandemic has affected the health attention in all dimensions, one of them, the exclusive breastfeeding assurance and her promotion. The high risk of contagion and the pandemic consequences have raised a number of concerns in future mothers or those who are breastfeeding because of the risk of a possible transmission of the virus through breast milk. Although SARS-CoV2 has no evidence of being active on breast milk, the fear of contagion has favored mother-child isolation policies. At this point, there are no evidence of vertical transmission and the risk of horizontal transmission in the infant is similar to the general population. Breastfeeding in newborn with COVID-19, can even favorably change the clinical course of the disease.

Exploring the rationale for thermotherapy in COVID-19.

Increased transmissibility of the pandemic severe acute respiratory coronavirus 2 (SARS-CoV-2) has been noted to occur at lower ambient temperatures. This is seemingly related to a better replication of most respiratory viruses, including SARS-CoV-2, at lower-than-core body temperatures (i.e., 33 °C vs 37 °C). Also, intrinsic characteristics of SARS-CoV-2 make it a heat-susceptible pathogen. Thermotherapy has successfully been used to combat viral infections in plants which could otherwise result in great economic losses; 90% of viruses causing infections in plants are positive-sense single-stranded ribonucleic acid (+ssRNA) viruses, a characteristic shared by SARS-CoV-2. Thus, it is possible to envision the use of heat-based interventions (thermotherapy or mild-temperature hyperthermia) in patients with COVID-19 for which moderate cycles (every 8-12 h) of mild-temperature hyperthermia (1-2 h) have been proposed. However, there are potential safety and mechanistic concerns which could limit the use of thermotherapy only to patients with mild-to-moderate COVID-19 to prevent disease progression rather than to treat patients who have already progressed to severe-to-critical COVID-19. Here, we review the characteristics of SARS-CoV-2 which make it a heat-susceptible virus, potential host mechanisms which could be enhanced at higher temperatures to aid viral clearance, and how thermotherapy could be investigated as a modality of treatment in patients with COVID-19 while taking into consideration potential risks.

Assessment of lamivudine, zidovudine, lopinavir, and ritonavir plasma levels in HIV-positive pregnant women: Drug monitoring application to improve patient safety.

Simultaneous therapeutic drug monitoring (TDM) of combination antiretroviral therapy (cART) is critical during pregnancy in order to improve clinical follow-up, monitor viral load, and patient adherence to treatment.A modified simple and fast ultra-high performance liquid chromatography coupled with tandem mass spectrometry and electrospray ionization (UPLC-ESI-MS/MS) method was developed and validated according to national and international guidelines for the simultaneous determination of lamivudine (LMV), zidovudine (ZDV), lopinavir (LPV), and ritonavir (RTV) concentrations in 100-µL plasma sample of Human Immunodeficiency Virus (HIV)-positive pregnant women. Protein precipitation using 0.1% formic acid in cold acetonitrile was used for sample preparation. The chromatographic separation was achieved with a run-time of 3.0 minutes and 3-µL injection on an ethylene bridged hybrid C18 column (2.1 µm × 50 mm, 1.7 µm), under gradient conditions using acetonitrile and formic acid (0.1%).The chromatographic method was used to analyze 10 plasma samples from 8 HIV pregnant women as a clinical patient routinely follow-up by applying TDM criteria.The protonated precursor/product ion transitions for LMV (230.18/112.08), ZDV (268.22/127.10), LPV (629.55/447.35), and RTV (721.50/296.20) were recorded in multiple-reaction-monitoring (MRM) mode. The calibration curve was linear in the range of 50-3,000, 75-4,500, 250-15,000, and 25-1,500-ng/mL for LMV, ZDV, LPV, and RTV, respectively. The range of accuracy was 97.2% to 100.1% and precision 3.4% to 12.7%. The method showed specificity and matrix effect values of < 15%. Minimum absolute recovery percentages (%CV) were 90.5 (5.4), 90.8 (5.0), 95.4 (3.5), and 93.7 (6.9), for LMV, ZDV, LPV, and RTV, respectively. Drug concentrations in patient samples had high inter-individual variability with %CV of 91.98%, 77.54%, 53.80%, and 92.16% for ZDV, LMV, LPV, and RTV, respectively. Two of the 8 patients showed no adherence due to the absence of Protease Inhibitors (PIs) levels in plasma.This technique demonstrated to be effective in therapeutic drug monitoring and is intended to be used in population pharmacokinetics specifically for HIV-positive pregnant women.

The role of complement in preterm birth and prematurity.

Complications of preterm birth (PTB) are the global leading cause of death in children younger than 5 years of age. Almost 15 million children are born prematurely in the world each year. Increasing evidence suggests that labor and delivery have many hallmarks of an inflammatory reaction, where complement activation has an active participation. As one of the most important components of inflammation, the role of complement during labor and PTB is becoming an attractive research target. The complement components C1q and C5b-9 are deposited on fetal membranes and release inflammatory mediators that contribute to uterine contractions, cervical ripening, cell chemotaxis, metalloproteinases production, membrane awaking and rupture, and it participates as a co-adjuvant in the onset and progress of labor. This article reviews a basic description of the complement system, its role in preterm birth and current concepts regarding its contribution in novel therapy strategies and new biomarkers.

Physician Knowledge, Attitudes, and Practices Related to Chagas Disease in Tabasco, Mexico.

We designed and implemented a survey of physician knowledge, attitudes, and practices with respect to Chagas disease in the state of Tabasco, Mexico. Seventy-eight public sector physicians from across the state responded via Research Electronic Data Capture, an online survey capture tool. Improved performance on knowledge-based questions (P < 0.01) and an increase in decisions to screen (P = 0.04) were associated with previous training specific to this disease. Our results provide important descriptive information regarding knowledge, attitudes, and practices among a group of public sector Mexican doctors and highlight the importance of Chagas disease-specific physician training for identification and, ultimately, treatment of patients affected by this disease.

Pathophysiology of Leishmania Infection during Pregnancy.

The pathological processes resulting from parasitic infection are known to have important impacts on the mother child dyad during pregnancy. The roles of parasite transmission and the maternal immune response have been described in diseases such as malaria, toxoplasmosis, and trypanosomiasis. However, the impact of parasites of the genus Leishmania, etiological agents of the neglected tropical diseases tegumentary leishmaniasis (TL) and visceral leishmaniasis (VL), is comparatively less well known, though it is an increasingly recognized concern for infected mothers and their fetuses. In this review, we first consider the pathophysiology of placental infection and transplacental transmission of this parasite, and then discuss the role and mechanisms of the maternal immune system in simultaneously mediating maternal-fetal infection and adverse pregnancy outcomes.

Inflammatory Response in Preterm and Very Preterm Newborns with Sepsis.

The response of the adaptive immune system is usually less intense in premature neonates than term neonates. The primary objective of this study was to determine whether immunological parameters vary between preterm (PT) neonates (≥32 weeks of gestational age) and very preterm (VPT) neonates (<32 weeks of gestational age). A cross-sectional study was designed to prospectively follow PT and VPT neonates at risk of developing sepsis. Plasma concentrations of IFN-γ, TNF-α, IL-6, IL-4, and IL-10 were detected using flow cytometry. C-reactive protein (C-RP) and the complex SC5b-9 were detected in the plasma using commercial kits. A total of 83 patients were included. The laboratory results and clinical histories showed that 26 patients had sepsis; 14 were VPT, and 12 were PT. The levels of C-RP, SC5b-9 (innate immune response mediators), and IL-10 or IL-4 (anti-inflammatory cytokines) were elevated during sepsis in both groups. IFN-γ, TNF-α, and IL-6 (proinflammatory cytokines) were differentially elevated only in PT neonates. The VPT neonates with sepsis presented increases in C-RP, SC5b-9, and anti-inflammatory cytokines but not in proinflammatory cytokines, whereas PT neonates showed increases in all studied mediators of inflammation.

Polymorphic variation of hypoxia inducible factor-1 A (HIF1A) gene might contribute to the development of knee osteoarthritis: a pilot study.

BACKGROUND: Osteoarthritis (OA) is a multifactorial degenerative condition of the whole joint with a complex pathogenesis whose development and progression is significantly mediated by interactions between the joint cartilage and articular tissues, particularly, proinflammatory mediators and oxidative stress, which results in cartilage deterioration and subchondral bone destruction. HIF-1 alpha regulates oxygen homeostasis in hypoxic tissues such as joint cartilage; efficiency of transcriptional activity of the HIF1A gene is strongly influenced by the presence of polymorphic variants. Given the loss of articular cartilage and with intention to restore damaged tissue, WISP-1 participates in the development of subchondral bone; further, its expression is highly increased in chondrocytes of OA patients. The aim of this study was to evaluate gene frequencies of HIF1A and WISP1 polymorphisms in Mexican patients suffering from knee OA. METHODS: We determined HIF1A rs11549465 (P582S), rs11549467 (A588T), and rs2057482 (C191T), and WISP1 rs2929970 (A2364G) polymorphisms in 70 Mexican patients with knee OA and compare them to those present in 66 ethnically matched healthy controls. Genotyping for these polymorphisms was performed by Real-Time PCR using TaqMan probes. RESULTS: Gene frequencies exhibited a significant increase of the CC genotype of rs11549465 polymorphism in knee OA patients as compared with those present in controls (P = 0.003 OR = 5.7, 95% CI = 1.7-21.6); CT genotype and T allele showed decreased frequency in the knee OA group vs. the controls (P = 0.003 OR = 0.2, CI = 0.05-0.6; and P = 0.004 OR = 0.2, CI = 0.05-0.65, respectively). Allele frequencies of the other polymorphic variants were similar in both patients and controls. CONCLUSIONS: These results suggest that the presence of the rs11549465 SNP (HIF1A) plays a role protective in the loss of articular cartilage in our population, and offers the possibility to further study the molecular mechanisms within cartilage and subchondral bone.

Design, synthesis and biological evaluation of quinazoline derivatives as anti-trypanosomatid and anti-plasmodial agents.

In this paper, the design, synthesis and biological evaluation of a set of quinazoline-2,4,6-triamine derivatives (1-9) as trypanocidal, antileishmanial and antiplasmodial agents are explained. The compounds were rationalized basing on docking studies of the dihydrofolate reductase (DHFR from Trypanosoma cruzi, Leishmania major and Plasmodium vivax) and pteridin reductase (PTR from T. cruzi and L. major) structures. All compounds were in vitro screened against both bloodstream trypomastigotes of T. cruzi (NINOA and INC-5 strains) and promatigotes of Leishmania mexicana (MHOM/BZ/61/M379 strain), and also for cytotoxicity using Vero cell line. Against T. cruzi, three compounds (5, 6 and 8) were the most effective showing a better activity profile than nifurtimox and benznidazole (reference drugs). Against L. mexicana, four compounds (5, 6, 8, and 9) exhibited the highest activity, even than glucantime (reference drug). In the cytotoxicity assay, protozoa were more susceptible than Vero cells. In vivo Plasmodium berghei assay (ANKA strain), the compounds 1, 5, 6 and 8 showed a more comparable activity than chloroquine and pyrimethamine (reference drugs) when they were administrated by the oral route. The antiprotozoal activity of these substances, endowed with redox properties, represented a good starting point for a medicinal chemistry program aiming for chemotherapy of Chagas' disease, leishmaniosis and malaria.

Blood SC5b-9 complement levels increase at parturition during term and preterm labor.

We explored the hypothesis that complement, an innate and adaptive immune effector, is active in the plasma of parturient women and is deposited on fetal membranes collected after delivery. A cross-sectional study was designed to evaluate complement activity at parturition. Pregnant women (n = 97) between 15 and 41 years of age were enrolled in a hospital protocol during the perinatal period to assess both SC5b-9 complement activity in blood and complement deposition on fetal membranes during parturition. Soluble SC5b-9 complement activity in plasma fractions was measured using a standard enzyme-linked immunosorbent assay (ELISA) that included specific anti-complement antibodies. Complement deposition on membranes was analyzed using immuno-dot blots and immunohistochemistry. Soluble SC5b-9 complement complex levels were increased in the plasma of women during term labor (TL; median 3361; range 1726-5670 ng/mL), preterm labor (PL; median 2958; range 1552-7092 ng/mL), and preterm premature rupture of membranes (PPROM; median 2272; range 167-6540 ng/mL) compared with pregnant women who were not in labor (P; median 1384; range 174-4570 ng/mL; P < 0.001, Kruskal-Wallis test). Active complement, as assessed by the C9 neo-antigen in C5b-9 complexes, was deposited on fetal membranes, with no difference between term and preterm delivery. The deposition of active complement on fetal membranes was confirmed by immunohistochemistry. Women who underwent non-labor-indicated Cesarean sections did not exhibit complement deposition. Soluble SC5b-9 complement complex levels increased in the plasma of women during parturition, and complement C5b-9 complexes were deposited on fetal membranes.

Antileishmanial activity of quinazoline derivatives: synthesis, docking screens, molecular dynamic simulations and electrochemical studies.

A series of quinazoline-2,4,6-triamine were synthesized and evaluated in vitro against Leishmania mexicana. Among them, N(6)-(ferrocenmethyl)quinazolin-2,4,6-triamine (H2) showed activity on promastigotes and intracellular amastigotes, as well as low cytotoxicity in mammalian cells. Docking and electrochemical studies showed the importance of both the ferrocene and the heterocyclic nucleus to the observed activity. H2 is readily oxidized electrochemically, indicating that the mechanism of action probably involves redox reactions.

Transplacental transmission of cutaneous Leishmania mexicana strain in BALB/c mice.

The vertical transmission of leishmaniasis has been reported in species that cause visceral leishmaniasis. However, this condition has scarcely been documented in species that cause cutaneous leishmaniasis. The aim of this study was to determine experimentally whether L. mexicana is transmitted vertically. A control group of BALB/c mice and a group infected with L. mexicana were mated, the gestation was monitored, and females were killed before delivery. Four resorptions (P = 0.023) and eight fetal deaths (P = 0.010) were observed in the infected female group; furthermore, the offspring body weight of the infected group was lower than the body weight of the healthy group (P = 0.009). DNA amplification by polymerase chain reaction (PCR) revealed that all placentas and maternal spleens as well as 39 of 110 fetal spleens obtained from the offspring of infected mothers tested positive for Leishmania. In conclusion, L. mexicana is transmitted transplacentally and causes fetal death, resorption, and reduction in offspring body weight.

Effect of ambient temperature on the clinical manifestations of experimental diffuse cutaneous leishmaniasis in a rodent model.

Dermal species of Leishmania have a relatively broad temperature range for optimal growth in vitro, with temperature differences accompanied by a form change. This suggests that when the host is living in moderate temperatures (22°C), infection may proceed at temperatures lower than those that occur in tropical regions (32°C), and a different clinical expression of the disease due to a different parasitic form may result. The aim of this study was to investigate the effect of environmental temperature on the clinical expression of the disease. BALB/C mice infected with Leishmania mexicana were housed at 32°±2°C or 22°±1°C, and assessed for the development of inflammation and the presence of parasites in organs using PCR and immunohistology. The clinical expression of leishmaniasis at 32°C included inflammation at the site of inoculation with swelling of the nose and tail, whereas at 22°C, up to 50% of the infected mice developed dry exfoliative dermatitis with alopecia on the dorsum. In both cases, parasite colonization was confirmed in the skin, with parasites at more external locations at 22°C. Parasite visceralization was confirmed in all internal organs and glands in both cases based on PCR and immunohistology. In conclusion, the clinical expression of diffuse leishmaniasis by Leishmania mexicana in laboratory mice is modified by temperature, from nodular inflammation at 32°C, to dry exfoliative dermatitis and alopecia at 22°C, with parasite visceralization in both cases.

Activity of hydroxyurea against Leishmania mexicana.

Leishmania mexicana is a protozoan parasite that causes a disease in humans with frequent relapses after treatment. It is also highly resistant to the currently available drugs. For this reason, there is an urgent need for more effective antileishmanial drugs. Hydroxyurea, an anticancer drug, is toxic to replicating eukaryotic cells and has been proven to be effective in arresting the Leishmania major cell cycle. In this study, hydroxyurea was tested in an in vitro model of intracellular Leishmania infection in macrophages. The parasite density in infected macrophages was measured by microscopy after incubation for various times and treatment with hydroxyurea at different concentrations. Viable parasites that could be transformed into promastigotes by shifting the temperature to 26 degrees C were counted every other day after the replacement of hydroxyurea with fresh medium. Meglumine antimoniate, the standard drug treatment for Leishmania mexicana, was used as a reference drug under the same experimental conditions. Hydroxyurea completely eliminated Leishmania parasites when it was used at a dosage of 10 or 100 microg/ml. Differences in the length of treatment needed to achieve elimination were as follows: the 10-microg/ml doses required 9 days, while 3 days was sufficient when 100 microg/ml was used. Hydroxyurea had a 50% effective dose of 0.015 microg/ml in vitro, which was observed on day 6 after exposure. Hydroxyurea is highly effective in killing intracellular amastigotes in vitro.