Biofilm eradication of Stenotrophomonas maltophilia by Levofloxacin and Trimethoprim-sulfamethoxazole.

Stenotrophomonas maltophilia is a non-fermenting Gram-negative drug-resistant pathogen causing healthcare-associated infections. Clinical isolates from Mexico were assessed for biofilm production by crystal violet staining. Antimicrobial susceptibility was evaluated using the broth microdilution method in planktonic and biofilm cells. The effect of antibiotics on the biofilm was visualized by fluorescence microscopy. Fifty isolates were included in the study, of which 28.0% were biofilm producers (64.2% from blood and 35.7% from respiratory samples). Resistance to levofloxacin (8.0%) and trimethoprim-sulfamethoxazole (44.0%) in planktonic cells increased to 100% in biofilm cells. Bacterial biofilm treated with several concentrations of both antibiotics was completely disrupted. In conclusion, S. maltophilia isolated from blood had higher biofilm production than those from respiratory samples. Resistance to antibiotics increased due to biofilm production. Antibiotic monotherapy might not be the best course of action for the treatment of S. maltophilia infections in Mexico, as they might also be causing biofilm production.

Previous cardiovascular injury is a prerequisite for immune checkpoint inhibitor-associated lethal myocarditis in mice.

AIMS: Immune checkpoint inhibitors (ICIs) are antineoplastic drugs designed to activate the immune system's response against cancer cells. Evidence suggests that they may lead to immune-related adverse events, particularly when combined (e.g., anti-CTLA-4 plus anti-PD-1), sometimes resulting in severe conditions such as myocarditis. We aimed to investigate whether a previously sustained cardiac injury, such as pathological remodelling due to hypertension, is a prerequisite for ICI therapy-induced myocarditis. METHODS: We evaluated the cardiotoxicity of ICIs in a hypertension (HTN) mouse model (C57BL/6). Weekly doses were administered up to day 21 after the first administration. Our analysis encompassed the following parameters: (i) survival and cardiac pathological remodelling, (ii) cardiac function assessed using pressure-volume (PV)-loops, with brain natriuretic peptide (BNP) serving as a marker of haemodynamic dysfunction and (iii) cardiac inflammation (cytokine levels, infiltration, and cardiac antigen autoantibodies). RESULTS: After the first administration of ICI combined therapy, the treated HTN group showed a 30% increased mortality (P = 0.0002) and earlier signs of hypertrophy and pathological remodelling compared with the untreated HTN group. BNP (P = 0.01) and TNF-α (<0.0001) increased 2.5- and 1.7-fold, respectively, in the treated group, while IL-6 (P = 0.8336) remained unchanged. Myocarditis only developed in the HTN group treated with ICIs on day 21 (score >3), characterised by T cell infiltration and increased cardiac antigen antibodies (86% showed a titre of 1:160). The control group treated with ICI was unaffected in any evaluated feature. CONCLUSIONS: Our findings indicate that pre-existing sustained cardiac damage is a necessary condition for ICI-induced myocarditis.

Association of the Interleukin 1B-31*C Proinflammatory Allele with the Severity of COVID-19 Patients: A Preliminary Report.

Individuals with no known comorbidities or risk factors may develop severe coronavirus disease 2019 (COVID-19). The present study assessed the effect of certain host polymorphisms and viral lineage on the severity of COVID-19 among hospitalized patients with no known comorbidities in Mexico. The analysis included 117 unrelated hospitalized patients with COVID-19. Patients were stratified by whether they required intensive care unit (ICU) admission: the ICU group (n = 40) and non-ICU group (n = 77). COVID-19 was diagnosed on the basis of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription-polymerase chain reaction (RT-PCR) assay and clinical and radiographic criteria. The presence of the IL1B-31 (T/C) polymorphism was determined for all patients using PCR and nucleotide sequencing. Genotyping of the IL-4 (-590, T/C) and IL-8 (-251, T/A) polymorphisms was performed by the amplification refractory mutation system-PCR method. Genotyping of IL1-RN was performed using PCR. Viral genome sequencing was performed using the ARTIC Network amplicon sequencing protocol using a MinION. Logistic regression analysis identified the carriage of IL-1 B*-31 *C as an independent potential risk factor (odds ratio [OR] = 3.1736, 95% confidence interval [CI] = 1.0748-9.3705, p = 0.0366) for ICU admission and the presence of IL-RN*2 as a protective factor (OR = 0.4371, 95% CI = 0.1935-0.9871, p = 0.0465) against ICU admission. Under the codominant model, the CC genotype of IL1B-31 significantly increased the risk of ICU admission (OR: 6.38, 95% CI: 11.57-25.86, p < 0.024). The IL1B-31 *C-IL-4-590 *T haplotype increased the risk of ICU admission (OR = 2.53, 95% CI = 1.02-6.25, p = 0.047). The 42 SARS-CoV-2 genomes sequenced belonged to four clades, 20A-20D. No association was detected between SARS-CoV-2 clades and ICU admission or death. Thus, in patients with no known comorbidities or risk factors, the IL1B-31*C proinflammatory allele was observed to be associated with the risk of ICU admission owing to COVID-19.

Histopathological, ultrastructural, and biochemical traits of apoptosis induced by peroxisomicine A1 (toxin T-514) from Karwinskia parvifolia in kidney and lung.

Peroxisomicine A1 (PA1) is a toxin isolated from the Karwinskia genus plants whose target organs are the liver, kidney, and lung. In vitro studies demonstrated the induction of apoptosis by PA1 in cancer cell lines, and in vivo in the liver. Apoptosis has a wide range of morphological features such as cell shrinkage, plasma membrane blistering, loss of microvilli, cytoplasm, and chromatin condensation, internucleosomal DNA fragmentation, and formation of apoptotic bodies that are phagocytized by resident macrophages or nearby cells. Early stages of apoptosis can be detected by mitochondrial alterations. We investigated the presence of apoptosis in vivo at the morphological, ultrastructural, and biochemical levels in two target organs of PA1: kidney and lung. Sixty CD-1 mice were divided into three groups (n = 20): untreated control (ST), vehicle control (VH), and PA1 intoxicated group (2LD50). Five animals of each group were sacrificed at 4, 8, 12, and 24 h post-intoxication. Kidney and lung were examined by morphometry, histopathology, ultrastructural, and DNA fragmentation analysis. Pre-apoptotic mitochondrial alterations were present at 4 h. Apoptotic bodies were observed at 8 h and increased over time. TUNEL positive cells were detected as early as 4 h, and the DNA ladder pattern was observed at 12 h and 24 h. The liver showed the highest value of fragmented DNA, followed by the kidney and the lung. We demonstrated the induction of apoptosis by a toxic dose of PA1 in the kidney and lung in vivo. These results could be useful in understanding the mechanism of action of this compound at toxic doses in vivo.

Effect of methanolic extract of Mimosa malacophylla A.Gray in vero and HEK-293 cell lines, and in the morphology of kidney and bladder of rats with induced urolithiasis.

ETHNOPHARMACOLOGICAL RELEVANCE: Urolithiasis is the presence of stones in the kidney, ureters, bladder and/or urethra; it is the third most frequent disease of the urinary tract. Mimosa malacophylla A. Gray, is a species distributed in northern Mexico, where people traditionally use it for its diuretic effect, and to treat kidney diseases; however, no scientific reports have been found in relation to its antiurolithic properties. AIM OF THE STUDY: This study aimed to obtain a qualitative phytochemical profile of the methanolic extract (ME) of M. malacophylla, and to evaluate its potential cytotoxic effect in vitro and its antiurolithic activity in vivo. MATERIAL AND METHODS: Phytochemical screening was performed to demonstrate the presence of secondary metabolite groups in the methanolic extract of M. malacophylla. In vitro cytotoxicity assays (MTT and nucleotide labeling with DAPI) were performed to evaluate the effect of the extract on kidney cell lines. Urolithiasis was induced in the bladder of Wistar rats introducing zinc disks for the calculus formation and exposed to three concentrations of ME. RESULTS: Phytochemical screening showed phenols, steroids, terpenoids and carbohydrates. In vitro analysis demonstrated that concentrations below 300 µg/mL of ME did not produce a cytotoxic effect on renal Vero and HEK-293 cells. In vivo analysis of 15 days of exposition, revealed that the extract at concentrations of 50 mg/kg to 150 mg/kg were effective as an antiurolithic treatment, and did not produce morphological alterations in kidney or bladder in murine model of induced urolithiasis. CONCLUSIONS: The antiurolithic activity may be attributed to the presence of flavonoids, steroids and terpenes detected in the phytochemical screening which have been reported to possess this activity. These results could be useful to evaluate new alternatives and their potential therapeutic effect to treat renal or urinary affections.

Improvement of antimicrobial susceptibility testing in biofilm-growingcoagulase-negative Staphylococcus hominis.

Coagulase-negative Staphylococcus hominis causes bloodstream infections and often can form biofilms on medical devices. This study aimed to improve the current methodology for antimicrobial susceptibility testing (AST) in biofilm-growing S. hominis isolates. Biofilm production of S. hominis was assessed using the crystal violet staining method in trypticase soy broth supplemented with 1% glucose (TSBglu1%), Mueller-Hinton broth (MHB), or MHBglu1% using flat-bottom plates or the Calgary device. Susceptibility to antibiotics was assessed using the broth microdilution method (MHB and TSBglu1%) in planktonic cells (round-bottom plates) and biofilm cells (flat-bottom plates and the Calgary device). Biofilm determination using TSBglu1% yielded better performance over MHB, and flat-bottom plates without agitation were preferred over the Calgary device. Higher fold dilution values between the minimum biofilm eradication concentration (MBEC) and the minimum inhibitory concentration (MIC) were obtained in MHB for almost all antibiotics, except for linezolid. TSBglu1% and flat-bottom polystyrene plates were preferred over MHB and the Calgary device for biofilm determination. AST in biofilm-growing S. hominis showed better performance using TSBglu1% compared to MHB. Therefore, when comparing MBEC and MIC values, AST in planktonic cells could also be performed using TSBglu1% instead of MHB.

Clinical and Immunologic Efficacy of the Recombinant Adenovirus Type-5-Vectored (CanSino Bio) Vaccine in University Professors during the COVID-19 Delta Wave.

Information regarding the efficacy of the recombinant adenovirus type-5-vectored (CanSino Bio) vaccine against the COVID-19 disease in a real-life setting is limited. A retrospective cohort study was carried out in the teaching university community of the metropolitan area of Monterrey, Mexico, through a four-section survey, and during the COVID-19 delta wave. Determination of IgG antibodies against SARS-CoV-2 spike (S) protein was performed in a subset of participants vaccinated with CanSino Bio. A total of 7468 teachers responded to the survey, and 6695 of them were fully vaccinated. Of those, 72.7% had CanSino Bio, 10.3% Pfizer, 8.4% AstraZeneca, 1.2% Moderna, and 2.7% others. Symptomatic breakthrough infections were recorded in those vaccinated with CanSino Bio (4.1%), AstraZeneca (2.1%), and Pfizer (2.2%). No difference was found between CanSino Bio and other vaccines regarding hospitalization, the need for mechanical ventilation, and death. For CanSino Bio recipients, anti-S antibodies were >50 AU/mL in 73.2%. In conclusion, primary breakthrough symptomatic infections were higher in the CanSino vaccinated group compared to other brands. Individuals with a previous infection had higher antibody levels than those who were reinfected and without infection. A boosted dose of CanSino is recommended for those individuals without a previous infection.

Prevalence of SARS-CoV-2 Variants of Concern and Variants of Interest in COVID-19 Breakthrough Infections in a Hospital in Monterrey, Mexico.

SARS-CoV-2 variants of concern (VOCs) or of interest (VOIs) causing vaccine breakthrough infections pose an increased risk to worldwide public health. An observational case-control study was performed of SARS-CoV-2 vaccine breakthrough infections in hospitalized or ambulatory patients in Monterrey, Mexico, from April through August 2021. Vaccination breakthrough was defined as a SARS-CoV-2 infection that occurred any time after 7 days of inoculation with partial (e.g., first dose of two-dose vaccines) or complete immunization (e.g., second dose of two-dose vaccines or single-dose vaccine, accordingly). Case group patients (n = 53) had partial or complete vaccination schemes with CanSino (45%), Sinovac (19%), Pfizer/BioNTech (15%), and AstraZeneca/Oxford (15%). CanSino was administered most frequently in ambulatory patients (p < 0.01). The control group (n = 19) received no COVID-19 vaccines. Among SARS-CoV-2 variants detected by whole-genome sequencing, VOC Delta B.1.617.2 predominated in vaccinated ambulatory patients (p < 0.01) and AY.4 in hospitalized patients (p = 0.04); VOI Mu B.1.621 was detected in four (7.55%) vaccinated patients. SARS-CoV-2 breakthrough infections in our hospital occurred mostly in patients vaccinated with CanSino due to the higher prevalence of CanSino vaccine administration in our population. These patients developed mild COVID-19 symptoms not requiring hospitalization. The significance of this study lies on the detection of SARS-CoV-2 variants compromising the efficacy of local immunization therapies in Monterrey, Mexico.

Cytotoxic Effect In Vitro of Acalypha monostachya Extracts over Human Tumor Cell Lines.

Acalypha monostachya (A. monostachya) is a plant that is used in traditional medicine as a cancer treatment; however, its effect has not been validated. In this study, the potential cytotoxic effects and morphological changes of A. monostachya were evaluated in human tumor cell lines. The aqueous (AE), methanolic (ME), and hexane (HE) extracts were obtained, and flavonoid-type phenolic compounds were detected, which indicates an antineoplastic effect. We observed a time-dependent and concentration-selective toxicity in human tumor cells. Additionally, the ME and HE showed the greatest cytotoxic effect at minimum concentrations compared to the AE, which showed this effect at the highest concentrations. All extracts induced significant morphological changes in tumor cells. The HeLa (cervix carcinoma) cells were more sensitive compared to the MDA-MB-231 (triple-negative breast cancer) cells. In conclusion, we demonstrated a cytotoxic in vitro effect of A. monostachya extracts in tumoral human cell lines. These results show the potential antineoplastic effects of A. monostachya in vitro. Hereafter, our lab team will continue working to usefully isolate and obtain the specific compounds of A. monostachya extracts with cytotoxic effects on tumor cells to find more alternatives for cancer treatment.

Neuropathic or systemic chronic intoxication with Karwinskia humboldtiana (Buckthorn) fruit? Histopathological effect in myocardial and skeletal muscle.

In accidental intoxicated animals and humans, Karwinskia humboldtiana (Kh) causes lesions in the central and peripheral nervous system and organs like the kidney, liver, and lung. The objective was to evaluate the histology of myocardium and skeletal muscle after experimental chronic intoxication with mature fruit of Kh in Wistar rat. Twenty-five rats were used and divided into five groups (n = 5): four intoxicated and one control. Kh fruit was ground, dried, sieved, and administered by an orogastric tube. Intoxicated rats received 3.5 g/kg body weight fractionated in 5 doses. Control rats received only water. Animals were euthanized at 24, 48, 58, and 112 days, respectively. Samples of the myocardium and skeletal muscle were obtained and processed for light microscopy evaluation. Morphological analyses were performed, including a microdensitometric analysis. Results showed areas of necrosis in the muscle fibers, fibers with vacuolated cytoplasm, and disorganization of myofilaments, as well as staining variations in both myocardium and skeletal muscle time-depending. Zones with loss of continuity of the external lamina were identified with PAS with the diastase histochemical method. Immunolabeling with specific antibodies demonstrated diminution of actin and desmin myofilaments. The microdensitometric analysis showed a statistically significant difference between the intoxicated vs control group. These findings demonstrate that chronic intoxication of Kh fruit also causes damage in myocardial and skeletal muscle, these alterations will be useful to understand that the toxic effects of Kh fruit in accidently intoxicated humans are systemic, and not only over the nervous system.

Hyaluronate Functionalized Multi-Wall Carbon Nanotubes Loaded with Carboplatin Enhance Cytotoxicity on Human Cancer Cell Lines.

Cancer is a major global public health problem and conventional chemotherapy has several adverse effects and deficiencies. As a valuable option for chemotherapy, nanomedicine requires novel agents to increase the effects of antineoplastic drugs in multiple cancer models. Since its discovery, carbon nanotubes (CNTs) are intensively investigated for their use as carriers in drug delivery applications. This study shows the development of a nanovector generated with commercial carbon nanotubes (cCNTs) that were oxidized (oxCNTs) and chemically functionalized with hyaluronic acid (HA) and loaded with carboplatin (CPT). The nanovector, oxCNTs-HA-CPT, was used as a treatment against HeLa and MDA-MB-231 human tumor cell lines. The potential antineoplastic impact of the fabricated nanovector was evaluated in human cervical adenocarcinoma (HeLa) and mammary adenocarcinoma (MDA-MB-231). The oxCNTs-HA-CPT nanovector demonstrate to have a specific antitumor effect in vitro. The functionalization with HA allows that nanovector bio-directed towards tumor cells, while the toxicity effect is attributed mainly to CPT in a dose-dependent manner.

Expression of the Wilms' tumour gene and its association with PPARß/δ in healthy skin and melanoma of horses.

The Wilms' tumour gene (WT1) has previously been described as an oncogene in several neoplasms of humans, including melanoma, and its expression increases cancer cell proliferation. Recent reports associate the expression of the PPARß/δ gene (peroxisome proliferator-activated receptor beta/delta) with the downregulation of WT1 in human melanoma and murine melanoma cell lines. The aim of this work was to analyse the expression of WT1 and its association with PPARß/δ in samples of healthy and melanoma-affected skin of horses by immunohistochemistry. WT1 protein expression was detected in healthy skin, mainly in the epidermis, hair follicle, sebaceous gland and sweat gland, while no expression was observed in equine melanoma tissues. Moreover, it was observed that PPARß/δ has a basal expression in healthy skin and that it is overexpressed in melanoma. These results were confirmed by a densitometric analysis, where a significant increase of the WT1-positive area was observed in healthy skin (128.66 ± 19.84 pixels 106) compared with that observed in melanoma (1.94 ± 0.04 pixels 106). On the other hand, a positive area with an expression of PPARß/δ in healthy skin (214.94 ± 11.85 pixels 106) was significantly decreased compared to melanoma (624.86 ± 181.93 pixels 106). These data suggest that there could be a regulation between WT1 and PPARß/δ in this disease in horses.

Differential expression of mast cell granules in samples of metastatic and non-metastatic colorectal cancer in patients.

Various cell types participate in the tumor process, in which the mast cells have been described; however, the role they play in colorectal adenocarcinoma has not yet been fully understood. Therefore, the present work aimed to compare employing histochemistry and immunohistochemistry, the number of mast cells and the content of some cytoplasmic granules in moderately differentiated non-metastatic and metastatic colorectal adenocarcinoma, analyzing tissue samples from patients. Histochemical techniques with Toluidine Blue (TBO), Periodic Schiff Acid (PAS), Alcian Blue/Periodic Acid-Schiff (PAB) and Alcian Blue/Safranin (ABS); as well as immunohistochemical reactions with anti-antibodies anti-Tryptase and anti-Chymase were applied to quantify total mast cells and content of some cytoplasmic granules. Statistical analysis was performed using SPSS V22.0 software (p ≤ 0.05). The degree of positivity of the reaction and degranulation of mast cells was reported in percentages. In our results, we observed that there are differences in the quantity and histochemical composition of the granules of mast cells (metastatic group PAS and ABS comparing the TBO reaction), as well as in the immunohistochemical composition between Tryptase and Chymase and the number of degranulated cells in both study groups (74 % degranulated mast cells in the metastatic group, 66 % integrate mast cells in the non-metastatic group). Therefore, we consider that the differences may be some of the probable factors that lead to metastasis of colorectal adenocarcinoma.

Hyaluronate Functionalized Multi-Wall Carbon Nanotubes Filled with Carboplatin as a Novel Drug Nanocarrier against Murine Lung Cancer Cells.

Carbon nanotubes (CNTs) have emerged in recent years as a potential option for drug delivery, due to their high functionalization capacity. Biocompatibility and selectivity using tissue-specific biomolecules can optimize the specificity, pharmacokinetics and stability of the drug. In this study, we design, develop and characterize a drug nanovector (oxCNTs-HA-CPT) conjugating oxidated multi-wall carbon nanotubes (oxCNTs) with hyaluronate (HA) and carboplatin (CPT) as a treatment in a lung cancer model in vitro. Subsequently, we exposed TC-1 and NIH/3T3 cell lines to the nanovectors and measured cell uptake, cell viability, and oxidative stress induction. The characterization of oxCNTs-HA-CPT reveals that on their surface, they have HA. On the other hand, oxCNTs-HA-CPT were endocytosed in greater proportion by tumor cells than by fibroblasts, and likewise, the cytotoxic effect was significantly higher in tumor cells. These results show the therapeutic potential that nanovectors possess; however, future studies should be carried out to determine the death pathways involved, as well as their effect on in vivo models.

WT1 expression as a potential biomarker of malignancy in canine breast tumor / La expresión de WT1 como un biomarcador potencial maligno en un tumor de mama canino

SUMMARY: Veterinary oncology is very important nowadays to get a better understanding of human carcinogenesis. Estrogen receptor, progesterone receptor and Human Epidermal Growth Factor receptor 2 are frequently evaluated by immunohistochemistry (HIC) in human breast tumor. WT1 is an oncogene, its overexpression has been detected in leukemia and diverse solid tumors like breast cancer, lung cancer and mesothelioma in humans. WT1 expression was evaluated in 15 canine breast tumors (CBT) diagnosed by histopathological analysis to find its relationship with neoplasia and malignancy. IHC and RT-PCR were performed in CBT tissues. Fisher´s test was used to analyze WT1 relationship with malignancy. Of the 15 tumors, 9 (60 %) were diagnosed as benign and 6 (40 %) were malignant. With IHC, WT1 expression was positive only in biopsies diagnosed as malignant. Expression of WT1 by RT-PCR was detected in 14 of the 15 tumors (93.33 %) as well as in control healthy mammary gland. Clinical significance: This study describes for the first time a close correlation between CBT and a positive result for WT1 expression with IHC; hence, it can be used as a biomarker for this neoplasia and as an indicator of malignancy. RT-PCR analysis also showed to be good option to detect WT1 expression. These results will be useful to further investigations to elucidate WT1-related signaling pathways in CBT. Also to know molecules that regulate the translation of this protein as a marker for tumor progression.

RESUMEN: La oncología veterinaria es muy importante hoy en día para comprender mejor la carcinogénesis humana. El receptor de estrógeno, el receptor de progesterona y el receptor 2 del factor de crecimiento epidérmico humano se evalúan con frecuencia mediante inmunohistoquímica (HIC) en tumores de mama humanos. WT1 es un oncogén, su sobreexpresión se ha detectado en leucemia y en diversos tumores sólidos como el cáncer de mama, cáncer de pulmón y mesotelioma en humanos. La expresión de WT1 se evaluó en 15 tumores de mama caninos (TCC) diagnosticados mediante análisis histopatológico para encontrar su relación con la neoplasia y la malignidad. IHC y RT-PCR se realizaron en tejidos CBT. La prueba de Fisher se utilizó para analizar la relación de WT1 con la malignidad. De los 15 tumores, 9 (60 %) fueron diagnosticados como benignos y 6 (40 %) fueron malignos. Con IHC, la expresión de WT1 fue positiva solo en biopsias diagnosticadas como malignas. La expresión de WT1 por RT-PCR se detectó en 14 de los 15 tumores (93,33 %), así como en el control de la glándula mamaria sana. Importancia clínica: este estudio describe por primera vez una estrecha correlación entre la TCC y un resultado positivo para la expresión de WT1 con IHC; por lo tanto, se puede utilizar como un biomarcador para esta neoplasia y como un indicador de malignidad. El análisis por RT-PCR también demostró ser una buena opción para detectar la expresión de WT1. Estos resultados serán útiles para futuras investigaciones para dilucidar las vías de señalización relacionadas con WT1 en la TCC. También para conocer moléculas que regulan la traducción de esta proteína como marcador de progresión tumoral.

Carbon nanotubes: An alternative for platinum-based drugs delivery systems.

Currently, nanomedicine is approaching the research of nanomaterials that could work as drug delivery systems, to increase the efficiency, specificity and safety of drugs reducing toxicity and side effects. In this regard, carbon nanotubes have acquired great interest due to their physicochemical properties. The use of platinum-based drugs is facing some troubles in the clinic due to their side effects such as nephrotoxicity, neutropenia, neurotoxicity, among others. In addition, cases of tumors resistant to these drugs have been recently observed. The goal of this review was to analyze the reports about the use of formulations of platinum-based drugs in carbon nanotubes, to know and establish the most functional and potential conditions for its use in cancer treatment, identifying perspectives and develop areas for the improvement of these nanomaterials in the application of cancer therapy.