Follow-Up Study of 17-ß Estradiol, Prolactin and Progesterone with the Kinetics and Prevalence of T. gondii Infection in Pregnant Women.

Toxoplasmosis is an infection caused by the parasite Toxoplasma gondii. One-third of the world's population has come into contact with this parasite. In Mexico, the prevalence is between 15% and 50% in the general population and 34.9% in women with high-risk pregnancies. In pregnancy, the highest incidence of infection occurs in the third trimester and fetal damage is inversely proportional to gestational age. Maternal hormones play a fundamental role in the immune response. There are very few studies, with controversial results, on the levels of increased hormones and their relationship to the kinetics of T. gondii infections during pregnancy. The aim was to determine the serum levels of 17-ß estradiol, prolactin, and progesterone, and their association with anti-T. gondii antibodies' kinetics in pregnancy. Fifty-two pregnant patients were studied. A questionnaire with sociodemographic and clinical aspects was used. Afterward, 10 mL of venous blood was collected by venipuncture every trimester. The concentrations of 17-ß estradiol, progesterone, and prolactin were measured, using the ELISA method. In addition, anti-Toxoplasma IgG and IgM antibodies were also determined in the first, second, and third trimester. The prevalence of anti-Toxoplasma IgG antibodies was 26.92% in the first and second trimester and 32.7% in the third trimester. In seropositive women, 17-ß estradiol increased in the second and third trimesters of pregnancy. Progesterone increased significantly p < 0.039 in the third trimester in these women, while prolactin increased in the second trimester with a statistical significance of p < 0.021. In addition, 17-ß estradiol, progesterone, and prolactin are associated with T. gondii infection during pregnancy. New studies are necessary to clarify the specific mechanisms of immune response related to these hormones during pregnancy.

n-Type Fullerene-Carbon Dots: Synthesis and Electrochemical and Photophysical Properties.

The covalent incorporation of C60 and C70 derivatives of the well-known n-type organic semiconductor PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) onto carbon dots (CD) is described. Morphological and structural characterization reveal combined features of both pristine starting materials (CD and PCBM). Electrochemical investigations evidenced the existence of additional reduction processes to that of CD or PCBM precursors, showing rich electron-acceptor capabilities, with multistep processes in an affordable and narrow electrochemical window (ca. 1.5 V). Electronic communication in the obtained nanoconjugated species were derived from steady-state absorption and emission spectroscopies, which showed bathochromically shifted absorptions and emissions well entering the red region. Finally, the lower fluorescence quantum yield of CD-PCBM nanoconjugates, compared with CD, and the fast decay of the observed emission of CD, support the existence of an electronic communication between both CD and PCBM units in the excited state.

Enhanced Thermoelectricity in Metal-[60]Fullerene-Graphene Molecular Junctions.

The thermoelectric properties of molecular junctions consisting of a metal Pt electrode contacting [60]fullerene derivatives covalently bound to a graphene electrode have been studied by using a conducting-probe atomic force microscope (c-AFM). The [60]fullerene derivatives are covalently linked to the graphene via two meta-connected phenyl rings, two para-connected phenyl rings, or a single phenyl ring. We find that the magnitude of the Seebeck coefficient is up to nine times larger than that of Au-C60-Pt molecular junctions. Moreover, the sign of the thermopower can be either positive or negative depending on the details of the binding geometry and on the local value of the Fermi energy. Our results demonstrate the potential of using graphene electrodes for controlling and enhancing the thermoelectric properties of molecular junctions and confirm the outstanding performance of [60]fullerene derivatives.

Supramolecular Assembly of Edge Functionalized Top-Down Chiral Graphene Quantum Dots.

The construction of supramolecular assemblies of heterogeneous materials at the nanoscale is an open challenge in science. Herein, new chiral graphene quantum dots (GQDs) prepared by amidation reaction introducing chiral amide groups and pyrene moieties into the periphery of GQDs are described. The analytical and spectroscopic data show an efficient chemical functionalization and the morphological study of the supramolecular ensembles using SEM and AFM microscopies reveals the presence of highly ordered fibers of several micrometers length. Fluorescence studies, using emission spectroscopy and confocal microscopy, reveal that the fibers stem from the π-π stacking of both pyrenes and GQDs, together with the hydrogen bonding interactions of the amide groups. Circular dichroism analysis supports the chiral nature of the supramolecular aggregates.

Assessing the Photoinduced Electron-Donating Behavior of Carbon Nanodots in Nanoconjugates.

Carbon nanodots (CNDs) undergo electron transfer in different scenarios. Previous studies have mainly focused on the electron-accepting features of CNDs in covalently linked donor-acceptor nanoconjugates. In view of this, we decided to carry out in this study the formation of covalently linked nanoconjugates that feature electron-donating pressure synthesized carbon nanodots (pCNDs) and electron-accepting 11,11,12,12-tetracyano-9,10-anthra-p-quinodimethane (TCAQ): pCND-TCAQ. The stability of the one-electron reduced form of TCAQ renders it the acceptor of choice. Detailed structural and electrochemical investigations allowed the characterization of pCND-TCAQ. Furthermore, investigations regarding intramolecular interactions, by means of steady-state and pump-probe transient absorption spectroscopies, allowed detection and characterization of three excited state species, in general, and the pCND•+-TCAQ•- charge-separated state, in particular.

Mono- and Tripodal Porphyrins: Investigation on the Influence of the Number of Pyrene Anchors in Carbon Nanotube and Graphene Hybrids.

A series of molecular precursors, containing one (1 and 3) or three (2 and 4) pyrene anchors, covalently linked to porphyrins (free base or Zn), were prepared and characterized. All of them enable their π-π stacking onto low-dimensional nanocarbons including single-walled carbon nanotubes (SWCNTs) and nanographene (NG), their individualization, and their characterization. Microscopic (TEM, AFM) and spectroscopic (steady-state UV-vis and fluorescence, spectroelectrochemistry, and transient absorption measurements) techniques were at the forefront of the characterizations and were complemented by Raman spectroscopy and theoretical calculations. Of great importance is the Raman analysis, which corroborated n-doping of the nanocarbons due to the interactions with 1-4 when probed in the solid state. In solution, the situation is, however, quite different. Efficient charge separation was only observed for the graphene-based system NG/3.

Synthesis of Highly Efficient Multivalent Disaccharide/[60]Fullerene Nanoballs for Emergent Viruses.

After the last epidemic of the Zika virus (ZIKV) in Brazil that peaked in 2016, growing evidence has been demonstrated of the link between this teratogenic flavivirus and microcephaly cases. However, no vaccine or antiviral drug has been approved yet. ZIKV and Dengue viruses (DENV) entry to the host cell takes place through several receptors, including dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN), so that the blockade of this receptor through multivalent glycoconjugates supposes a promising biological target to inhibit the infection process. In order to get enhanced multivalency in biocompatible systems, tridecafullerenes appended with up to 360 1,2-mannobiosides have been synthesized using a strain-promoted cycloaddition of azides to alkynes (SPAAC) strategy. These systems have been tested against ZIKV and DENV infection, showing an outstanding activity in the picomolar range.

Toxoplasma infection in kidney donors and transplant recipients from Western Mexico: A one-year follow-up.

PURPOSE: Solid organ transplant recipients are highly susceptible to Toxoplasma gondii infection. We aimed to describe the 12-month follow-up risk of seroconversion in renal transplant recipients. METHODOLOGY: Anti-T gondii antibodies were investigated in donors and recipients of renal transplants. In donors, anti-T gondii were evaluated before transplantation. In recipients, anti-T gondii were monitored over a 12-month period to evaluate potential seroconversion or reactivation. IgG and IgM anti-T gondii antibodies were investigated through enzyme immunoassay and Western blot. Molecular diagnosis was performed on peripheral blood leukocytes using PCR to amplify fragments corresponding to the T gondii B1 gene and the repetitive 529-bp element. RESULTS: The basal frequency of seropositive IgG anti-T gondii antibodies was higher in donors than in recipients (38.4% vs 25.2%; P = .03). During the 12-month follow-up, the accumulated seroconversion to IgG and IgM antibodies was 3/99 (3.0%), and the accumulated reactivation was 11/99 (11.0%). None of the samples exhibited positivity to T gondii DNA. CONCLUSIONS: This study showed that there is an increased risk of seroconversion or reactivation in renal transplant recipients over a 12-month follow-up. Our data suggest that prophylaxis with trimethoprim and sulfamethoxazole effectively prevented toxoplasmosis, since neither T gondii DNA nor clinical toxoplasmosis was detected.

Hormonal modulation of Toxoplasma gondii infection: Regulation of hormonal receptors and cytokine production in THP-1 cells.

BACKGROUND: Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan able to infect humans and it is common in pregnant women. During pregnancy and lactation, there are changes in the concentration of 17ß-estradiol (E2), progesterone (Prg), and prolactin (PRL). It is known that a proinflamatory response reduces the susceptibility to be infected, and this response may change according to hormonal impairment. Monocytes and macrophages are the main barrier against many intracellular microorganisms, due to their ability to produce cytokines. The aim of this work was to determine the effect of E2, progesterone, and PRL on the infective capacity of T. gondii, proinflamatory immune response modulation and the expression of hormonal receptors on THP-1 cell stimulated with T. gondii. METHODS: The THP-1 cells were infected with 1500 T. gondii tachyzoites, of RH strain. Stimuli were conducted with recombinant PRL (200 ng/mL), E2 (40 nM) y Prg (40 nM). MTT assays were performed to evaluate cellular viability. Western blot assays were carried out to evaluate the expression of the hormonal receptors (PRLR, ERα, and ERß). Cytokines produced were measured with a magnetic bead kit directed to 17 cytokines. RESULTS: Stimuli with E2 and Prg increased T. gondii infection in monocytes after 48 h; however, no differences in infection were observed in PRL stimulus. The E2 decreased the secretion of IL-12 and IL-1ß and PRL did not modify the production of these cytokines in THP-1 cells stimulated with T. gondii; however, both hormones increased the production of IL-10. Besides, PRL augmented the production of IL-4 and IL-13. In contrast, Prg reduced these cytokines. Our results show that T. gondii induces the expression of ERα and ERß and lowers PRLR. The hormones modify the expression of the receptors of other hormones: Prg decreases PRLR, ERß and increases ERα; E2 diminishes PRLR; and PRL decreases ERα and ERß expression. CONCLUSION: The hormones can increase T. gondii infection and could be mediating an anti-inflammatory response in THP-1 cells. T. gondii induces changes in the expression of hormonal receptors.

Anion-π Catalysis on Carbon Nanotubes.

Induced π acidity from polarizability is emerging as the most effective way to stabilize anionic transition states on aromatic π surfaces, that is, anion-π catalysis. To access extreme polarizability, we propose a shift from homogeneous toward heterogeneous anion-π catalysis on higher carbon allotropes. According to benchmark enolate addition chemistry, multi-walled carbon nanotubes equipped with tertiary amine bases outperform single-walled carbon nanotubes. This is consistent with the polarizability of the former not only along but also between the tubes. Inactivation by π-basic aromatics and saturation with increasing catalyst concentration support that catalysis occurs on the π surface of the tubes. Increasing rate and selectivity of existing anion-π catalysts on the surface of unmodified nanotubes is consistent with transition-state stabilization by electron sharing into the tubes, i.e., induced anion-π interactions. On pristine tubes, anion-π catalysis is realized by non-covalent interfacing with π-basic pyrenes.

Nanocarbon-Based Glycoconjugates as Multivalent Inhibitors of Ebola Virus Infection.

SWCNTs, MWCNTs, and SWCNHs have been employed as virus-mimicking nanocarbon platforms for the multivalent presentation of carbohydrates in an artificial Ebola virus infection model assay. These carbon nanoforms have been chemically modified by the covalent attachment of glycodendrons and glycofullerenes using the CuAAC "click chemistry" approach. This modification dramatically increases the water solubility of these structurally different nanocarbons. Their efficiency in blocking DC-SIGN-mediated viral infection by an artificial Ebola virus has been tested in a cellular experimental assay, finding that glycoconjugates based on MWCNTs functionalized with glycofullerenes are potent inhibitors of viral infection.

Chemical functionalization and characterization of graphene-based materials.

Graphene-based materials (GBMs), with graphene, their most known member, at the head, constitute a large family of materials which has aroused the interest of scientists working in different research fields such as chemistry, physics, or materials science, to mention a few, arguably as no other material before. In this review, we offer a general overview on the most relevant synthetic approaches for the covalent and non-covalent functionalization and characterization of GBMs. Moreover, some representative examples of the incorporation into GBMs of electroactive units such as porphyrins, phthalocyanines, or ferrocene, among others, affording electron donor-acceptor (D-A) hybrids are presented. For the latter systems, the photophysical characterization of their ground- and excited-state features has also been included, paying particular attention to elucidate the fundamental dynamics of the energy transfer and charge separation processes of these hybrids. For some of the presented architectures, their application in solar energy conversion schemes and energy production has been also discussed.

Exploring Tetrathiafulvalene-Carbon Nanodot Conjugates in Charge Transfer Reactions.

Carbon nanodots (CNDs) were synthesized using low-cost and biocompatible starting materials such as citric acid/urea, under microwave irradiation, and constant pressure conditions. The obtained pressure-synthesized CNDs (pCNDs) were covalently modified with photo- and electroactive π-extended tetrathiafulvalene (exTTF) by means of a two-step esterification reaction, affording pCND-exTTF. The electronic interactions between the pCNDs and exTTF were investigated in the ground and excited states. Ultrafast pump-probe experiments assisted in corroborating that charge separation governs the deactivation of photoexcited pCND-exTTF. These size-regular structures, as revealed by AFM, are stable electron donor-acceptor conjugates of interest for a better understanding of basic processes such as artificial photosynthesis, catalysis, and photovoltaics, involving readily available fluorescent nanodots.

Modified SWCNTs with amphoteric redox and solubilizing properties.

A complementary double-covalent functionalization of single-wall carbon nanotubes (SWCNTs) that involves both solubilizing ionic liquids and electroactive moieties is reported. Our strategy is a simple and efficient methodology based on the stepwise functionalization of the nanotube surface with two different organic moieties. In a first instance, oxidized SWCNTs are amidated with ionic liquid precursors, and further treated with n-butyl bromide to afford SWCNTs functionalized with 1-butylimidazolium bromide. This approach allows tuneable polarity induced by anion exchange, which has an effect on the relative solubility of the modified SWCNTs in water. Subsequently, a 1,3-dipolar cycloaddition reaction was performed to introduce the electron-acceptor 11,11,12,12-tetracyano-9,10-anthra-para-quinodimethane (TCAQ) unit on the SWCNTs. Furthermore, to evaluate the influence of the functional group position, the TCAQ electroactive molecule was anchored through an esterification reaction onto previously oxidized SWCNTs, followed by the Tour reaction to introduce the ionic liquid functions. IR and Raman spectroscopies, thermogravimetric analysis (TGA), UV/Vis/NIR spectroscopy, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were employed and clearly confirmed the double-covalent functionalization of the SWCNTs.

Safety assessment of new nanodiamonds@corrole hybrids addressed by the response of RAW-264.7 macrophages.

Safety assessment of carbon nanomaterials is of paramount importance since they are on the frontline for applications in sensing, bioimaging and drug delivery. The biocompatibility and safety of functionalized nanodiamonds (NDs) are here addressed through the study of the pro-inflammatory response of RAW-264.7 macrophages exposed to new nanodiamonds@corrole hybrids. The corrole unit selected is as a prototype for a hydrophobic organic molecule that can function as a NIR fluorophore reporter, an optical sensor, a photodynamic therapy agent or a photocatalyst. The new functional nanohybrids containing detonated nanodiamonds (NDs) were obtained through esterification using carboxylated NDs and glycol corroles. The success of the covalent functionalization via carbodiimide activation was confirmed through X-ray photoelectron spectroscopy (XPS), Raman and Fourier transform infrared (FTIR) spectroscopy. The UV-vis absorption and emission spectra of the hybrids are additive with respect to the corrole features. The cellular uptake, localization, cell viability and effects on immune cell activation of the new hybrids and of the precursors were carefully investigated using RAW-264.7 macrophages. Overall results showed that the ND@corrole hybrids had no pro-inflammatory effects on the RAW-264.7 macrophage cell line, making them an ideal candidate for a wide range of biomedical applications.

Prevalence of Toxoplasma gondii Measured by Western Blot, ELISA and DNA Analysis, by PCR, in Cats of Western Mexico.

Toxoplasma gondii is the causative agent of toxoplasmosis in humans and animals. The sexual reproductive cycle of Toxoplasma takes place in the small intestine of felines, the definitive hosts. In the final part of the sexual cycle, T. gondii forms oocysts in infected cats. Oocysts transferred via the faeces to the environment are highly infectious to both animals and humans. This study aimed to determine the prevalence and risk factors associated with T. gondii infection in cats from the metropolitan region of Guadalajara in western Mexico. Western blotting and ELISA for anti-Toxoplasma IgG antibodies was performed, and Toxoplasma DNA was identified using polymerase chain reaction. Prevalence of anti-T. gondii antibodies was 14.8% (44/297), and only 2/297 cases were positive for PCR. Cats older than one year were at an increased risk of infection (OR = 3.9, 95% CI 1.844-8.362). Sex, raw meat feeding, hunting habits, vaccination status, and body condition were not associated with positivity. The prevalence of T. gondii infection determined with Western blot in cats in the metropolitan area of Guadalajara, Jalisco, Mexico, was lower than that reported in previous studies.

17ß-estradiol modulates the expression of hormonal receptors on THP-1 T. gondii-infected macrophages and monocytes in an AKT and ERK-dependent manner.

Toxoplasma gondii (T. gondii) is a parasite common in pregnancy. Monocytes and macrophages are a significant immunologic barrier against T. gondii by boosting up inflammation. This outcome is highly regulated by signaling pathways such as MAPK (ERK1/2) and PI3K (AKT), necessary in cell growth and proliferation. It may be associated with the hormonal receptors' modulation by T. gondii (Estrogen Receptor (ER)-α, ERß, G Protein-coupled ER (GPER), and Prolactin Receptor (PRLR)), as previously reported by our research group. 17ß-estradiol also activates MAPK and PI3K; however, its combined effect in THP-1 monocytes and macrophages, infected with T. gondii, has not yet been evaluated. This study aimed to evaluate the combined effect of 17ß-estradiol in the activation of signaling pathways using a model of THP-1 monocytes and macrophages infected with T. gondii. THP-1 monocytes were cultured and differentiated into macrophages. Inhibition of AKT and ERK1/2 was performed with specific inhibitors. Stimuli were performed with 17ß-estradiol (10 nM), T. gondii (20,000 tachyzoites), and both conditions for 48 h. Proteins were extracted and quantified, and Western Blot assays were performed. 17ß-estradiol performed activation of ERK1/2 and AKT in T. gondii-infected macrophages. 17ß-estradiol modulated the expression of hormonal receptors in infected cells: increases the PRLR and PrgR in T. gondii-infected macrophages and decreases the PRLR and ERα in T. gondii-infected monocytes. As for GPER, its expression is abolished by T. gondii, and 17ß-estradiol cannot restore it. Finally, the blockage of ERK and AKT pathways modified the expression of hormonal receptors. In conclusion, 17ß-estradiol modifies the receptors of T. gondii-infected THP1 macrophages and monocytes in an ERK/AKT dependent manner.

Effect of 17ß-Estradiol, Progesterone, and Tamoxifen on Neurons Infected with Toxoplasma gondii In Vitro.

Toxoplasma gondii (T. gondii) is the causal agent of toxoplasmosis, which produces damage in the central nervous system (CNS). Toxoplasma-CNS interaction is critical for the development of disease symptoms. T. gondii can form cysts in the CNS; however, neurons are more resistant to this infection than astrocytes. The probable mechanism for neuron resistance is a permanent state of neurons in the interface, avoiding the replication of intracellular parasites. Steroids regulate the formation of Toxoplasma cysts in mice brains. 17ß-estradiol and progesterone also participate in the control of Toxoplasma infection in glial cells in vitro. The aim of this study was to evaluate the effects of 17ß-estradiol, progesterone, and their specific agonists-antagonists on Toxoplasma infection in neurons in vitro. Neurons cultured were pretreated for 48 h with 17ß-estradiol or progesterone at 10, 20, 40, 80, or 160 nM/mL or tamoxifen 1 µM/mL plus 17ß-estradiol at 10, 20, 40, 80, and 160 nM/mL. In other conditions, the neurons were pretreated during 48 h with 4,4',4″-(4-propyl-[1H] pyrozole-1,3,5-triyl) trisphenol or 23-bis(4-hydroxyphenyl) propionitrile at 1 nM/mL, and mifepristone 1 µM/mL plus progesterone at 10, 20, 40, 80, and 160 nM/mL. Neurons were infected with 5000 tachyzoites of the T. gondii strain RH. The effect of 17ß estradiol, progesterone, their agonists, or antagonists on Toxoplasma infection in neurons was evaluated at 24 and 48 h by immunocytochemistry. T. gondii replication was measured with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay. 17ß-Estradiol alone or plus tamoxifen reduced infected neurons (50%) compared to the control at 48 h. Progesterone plus estradiol decreased the number of intracellular parasites at 48 h of treatment compared to the control (p < 0.001). 4,4',4″-(4-propyl-[1H] pyrozole-1,3,5-triyl) trisphenol and 23-bis(4-hydroxyphenyl) propionitrile reduced infected neurons at 48 h of treatment significantly compared to the control (p < 0.05 and p < 0.001, respectively). The Toxoplasma infection process was decreased by the effect of 17ß-estradiol alone or combined with tamoxifen or progesterone in neurons in vitro. These results suggest the essential participation of progesterone and estradiol and their classical receptors in the regulation of T. gondii neuron infection.

Toxoplasmosis Is More Frequent in Schizophrenia Patients Than in the General Population in Mexico and Is Not Associated with More Severe Course of Schizophrenia Measured with the Brief Psychiatric Rating Scale.

Toxoplasmosis is a disease, which was discovered in 1908, caused by the intracellular parasite Toxoplasma gondii. T. gondii infects neuronal, glial, and muscle cells, and chronic infections are characterized by the presence of cysts, in the brain and muscle cells, formed by bradyzoites. T. gondii is capable of synthesizing L-DOPA, a precursor of dopamine. Dopamine is a neurotransmitter that is key in the etiology of neuropsychological disorders such as schizophrenia. Previous studies have shown high levels of IgG Toxoplasma antibodies in schizophrenia patients. Many published studies show that the prevalence of toxoplasmosis is higher in schizophrenia patients. In this study, we aimed to identify the prevalence of Toxoplasma infection in patients with schizophrenia and the relationships between, sociodemographic factors and the Brief Psychiatric Rating Scale. A total of 27 schizophrenic patients were included and IgG anti-T. gondii was determined in serum samples by ELISA. The Brief Psychiatric Rating Scale, sociodemographic factors were associated with seropositivity. We found that the prevalence of Toxoplasma antibodies was 51.7%. In the Brief Psychiatric Rating Scale, statistical significant association (p = 0.024) was found in Item 13 which is related to motor retardation, however, the association turned non-significant after of correction for multiple tests or after of analyzed with a logistic regression p = 0.059, odds ratio (OR) = 2.316 with a 95% confidence interval [0.970 to 5.532]. Other association was not found between toxoplasmosis and others factors. The prevalence of toxoplasmosis on our population under study was significantly higher than that reported by general population or other group of Mexican schizophrenia patients.

Occult hepatitis B in kidney transplants recipients and donors from Western Mexico.

BACKGROUND: Occult hepatitis B virus infection (OBI) is defined as the presence of hepatitis B virus (HBV) DNA in serum and/or liver from HBsAg-negative subjects. Our aim was to determine OBI frequency in serum and genomic DNA in patients undergoing renal transplant and their cognate donors in a selected population from Western Mexico. METHODS: Blood samples were obtained from 94 donors and their cognate recipients (188 participants) before kidney transplantation. Identification of HBV DNA was carried-out by nested (S-region) and semi-nested (Pol-region) PCR in both genomic and serum DNA samples from 188 participants at pre-surgical stage and from a subset of 73 recipients at three-month follow-up. RESULTS: HBV-DNA was not detected in either genomic or serum DNA samples from recipients or donors prior to transplantation. After three-months of follow-up, 2 out of 73 (2.7%, 95% CI: 0.9-11.9%) recipients were positive to HBV-DNA (Pol-region) in genomic DNA samples using a high sensitivity Taq DNA polymerase. CONCLUSIONS: OBI incidence in recipients of kidney transplant may be higher than previously recognized. Detection of HBV-DNA was higher in genomic DNA than in serum samples using a high sensitivity Taq DNA polymerase. To the best of our knowledge, this is the first report regarding this specific topic in Mexicans.