Relationship between microstructure formation and in vitro starch digestibility in baked gluten-starch matrices.

Increased prevalence of diabetes prompts the development of foods with reduced starch digestibility. This study analyzed the impact of adding soluble dietary fiber (inulin-IN; polydextrose-PD) to baked gluten-starch matrices (7.5-13%) on microstructure formation and in vitro starch digestibility. IN and PD enhanced water-holding capacity, the hardness of baked matrices, and lowered water activity in the formulated matrices, potentially explaining the reduced starch gelatinization degree as IN or PD concentration increased. A maximum gelatinization decrease (26%) occurred in formulations with 13% IN. Micro-CT analysis showed a reduction in total and open porosity, which, along with the lower gelatinization degree, may account for the reduced in vitro starch digestibility. Samples with 13% IN exhibited a significantly lower rapidly available glucose fraction (8.56 g/100 g) and higher unavailable glucose fraction (87.76 g/100 g) compared to the control (34.85 g/100 g and 47.59 g/100 g, respectively). These findings suggest the potential for developing healthier, starch-rich baked foods with a reduced glycemic impact.

Setting course for a translational pharmacology and a predictive toxicology based on the numerical probability of clinical relevance.

For a significant share of the chemicals, current bioassays mispredicted the outcomes in the reference methods they simulate. For any drug or chemical, and depending on the regulatory or corporate situation, three different approaches calculate the numerical probability by which agreement (or discrepancy) can be statistically expected between (1) the result of a predictive bioassay, and (2) the outcome on its reference method. If such concordance is expected with enough confidence based on a sufficient percentage probability, then specific results from that bioassay can be considered as correctly predictive. The statistical approaches analyzed in this article assist in valuable tasks, including (1) a better translation of the clinical relevance (or insignificance) of specific preclinical findings; (2) waiving unnecessary animal testing (or any other unpredictive testing; e.g., a given in vitro bioassay), and (3) in advancing only the most promising candidates in the pharmaceutical, pesticide, or chemical development process.

Applying Bayesian forecasting to predictive toxicology: The probability of innate carcinogenicity to humans of colorants synthesized from benzidine.

The preclinical identification of health hazards relies on the performance (the historic concordance to the respective gold standard) of regulatorily recommended bioassays. However, any testing with less than 100% sensitivity (or 100% specificity) can deliver false results (outcomes discordant to the respective gold standard). Conversely, the predictive values approach (a.k.a. Bayesian forecasting) weighs (1) the performance of the predictive bioassay (battery, or framework) with (2) the prevalence of -positivity to the respective gold standard- in the most representative category to which the test substance can be allocated. Thus, the predictive values approach (PVA) provides the numeric probability for the toxicity to humans of chemicals that, circumstantially, are evaluable only through nonclinical data. Consequently, the PVA improves the predictivity of nonclinical toxicology, and increases the impact of hazard identifications entirely based on preclinical data. This article aimed to introduce the PVA through a worked example. Due to their toxicological homogeneity and public health relevance, the superfamily of colorants synthesized from benzidine (BZ) or some mutagenic congeners was selected (colorings hereafter mentioned as BZ-related-colorants). Through the PVA, the numeric probability of innate carcinogenicity to humans of 259 BZ-related-colorants was either estimated from rodent carcinogenesis bioassays (RCBs) or predicted from methods alternative to the RCB. A discussion was provided on (1) some limitations and implications of the PVA, and (2) the probable significance of the predictive values figured here for 259 BZ-related-colorings.

The numerical probability of carcinogenicity to humans of some antimicrobials: Nitro-monoaromatics (including 5-nitrofurans and 5-nitroimidazoles), quinoxaline-1,4-dioxides (including carbadox), and chloramphenicol.

Many substances are already tested in the long-term rodent bioassay (RCB). Nonetheless, statements such as the following are common in the regulatory literature: "the significance of the carcinogenicity findings in rodents relative to the therapeutic use of drugs in humans is unknown." (U.S. FDA prescribing information for nitrofurantoin). In the absence of epidemiological data, chemicals carcinogenic in RCBs are typically classified as either possibly or probably carcinogenic to humans, particularly without the -numerical probability for the carcinogenicity to humans- (PPV) of the classified substance. Through the biostatistics-based and regulatorily pertinent -predictive values approach- (PVA), the present study investigated the PPV of several antimicrobials relevant to human or veterinary medicine. A combination of structure-activity relationship, mutagenicity, and tumor-related histopathology was used to resolve reliable and pertinent PPVs. For 62 specific antimicrobials (e.g., carbadox), a 97.9% (or more) probability of carcinogenicity to humans was estimated. For nitrofurantoin, a 99.9% probability of carcinogenicity to humans was reckoned. Therefore, a risk-benefit evaluation on the in-force authorization of nitrofurantoin for uncomplicated human urinary infections is needed. A discussion was provided on the involved mechanisms of carcinogenic action and some regulatory implications of the findings. Neither this study nor the PVA aimed to encourage indiscriminate animal testing but the contrary, to reduce unnecessary or redundant in vivo testing by powering the predictivity of nonclinical toxicology.

The 2-year rodent bioassay in drug and chemical carcinogenicity testing: Performance, utility, and configuration for cancer hazard identification.

For several intended uses of chemicals, the 2-year rodent bioassay (RCB) has been the benchmark method to screen the carcinogenicity to humans of substances, according to the hazard identification sphere. Despite the ongoing controversy around this traditional testing, the RCB is in force and being used by stakeholders. After assembling the RCB's ability to forecast the carcinogenicity to humans of substances, the current review aimed to provide a discussion on the RCB's (1) sensitivity and specificity; (2) utility; (3) configuration, and (4) provisional role in the regulatory policy. In general, RCBs conducted at maximum tolerated doses (MTDs) exhibited a functional ability to (1) not missing the great majority of human carcinogens, and to (2) not responding to the large majority of human non-carcinogens. There is citable evidence supporting the use of MTDs to render RCBs as sensitive as possible, particularly provided the ethically-justified small samples used in RCBs. The literature shows that rodent-specific mechanisms of chemical carcinogenesis contribute significant unspecificity to RCBs. Nonetheless, the paradox between a functional sensitivity and a significant unspecificity can be predictively resolved through the application of Bayesian forecasting. In terms of performance to forecast the carcinogenicity to humans of either genotoxic or non-genotoxic substances, 2-species-RCBs added no value over the rat-RCB. Nevertheless, there is preliminary evidence cautioning that 15% of the rodent carcinogens probably carcinogenic to humans could be missed if mouse-RCBs are indiscriminately discontinued. More than thirteen RCB-related issues relevant to regulatory pharmacology and toxicology were discussed and summarized in this review.

The numerical probability of carcinogenicity to humans of some pharmaceutical drugs: Alkylating agents, topoisomerase inhibitors or poisons, and DNA intercalators.

The nonclinical branch of regulatory pharmacology has traditionally relied on the sensitivity and specificity of regulatorily recommended bioassays. Nonetheless, any predictive testing (eg, safety pharmacology) with less than 100% sensitivity or 100% specificity is prone to deliver false positive or negative results (namely, outcomes discordant to the clinical gold standard). It was recently suggested that the statistics-based and regulatory pertinent "predictive values approach" (PVA) might help to reach a more predictive use of preclinical testing data. To resolve the associated probability of carcinogenicity to humans, the PVA was applied to 37 pharmaceuticals bearing inadequate epidemiological evidence of carcinogenicity, but identifiable as unequivocal mutagens. According to current knowledge, a 98.9% (or more) probability of carcinogenicity to humans was reckoned for those 37 genotoxic drugs. Accordingly, these pharmaceutical drugs might be either scientifically or regulatorily regarded as "carcinogenic to humans." In the USA, European Union, or Canada as examples, the great majority of these 37 pharmaceuticals are authorized for medical use in humans. From the results of the present appraisal, the following is suggested (1) for the pharmaceuticals listed in this report, to include significant carcinogenicity warnings in their prescribing information; (2) to conduct pharmacoepidemiology studies or risk-benefit analyses (if warranted), and (3) based on the respective risk-benefit analyses, to re-evaluate the authorization of hydralazine and phenoxybenzamine as antihypertensives, oxcarbazepine as an anticonvulsant, and phenazopyridine as a urinary tract antimicrobial or analgesic. For the four latter drugs (eg, phenoxybenzamine), a 99.5% probability of carcinogenicity to humans was estimated.

Idiopathic Acquired Hemophilia A, a Rare Cause of Bleeding: A Case Report and Literature Review.

BACKGROUND Acquired hemophilia is a bleeding disorder mediated by an autoimmune process, in which antibodies against clotting factors are developed. This is a rarely suspected complex condition in which the initial manifestations are spontaneous bleeding in the skin, soft tissues, and mucosa in patients with no known history of bleeding disorders. Most of the cases are idiopathic (50%), but it can be associated with autoimmune diseases, malignancy, pregnancy, and medications. The most frequent type is mediated by inhibitors against factor VIII, followed by coagulation factor IX and XI. It is a disease with high morbidity and mortality rates without adequate treatment. Diagnosis is based on the detection of low concentrations of clotting factors and the presence of an inhibitor. CASE REPORT We present 2 cases of patients with spontaneous bleeding in whom the diagnosis of idiopathic acquired hemophilia A was made, an extensive malignancy study was performed that was negative, and the presence of autoimmunity markers (positive antinuclear antibodies (ANA)) was observed, without any another sign of autoimmune disease. They received immunosuppressive therapy with bleeding control and inhibitor eradication. CONCLUSIONS Acquired hemophilia A is a rare but potentially lethal disease, representing a medical challenge from its diagnosis to its treatment. An early recognition and treatment are fundamental because delays are associated with adverse outcomes. Optimal management includes the workup and treatment for an underlying disease, use of "bypass" agents when active bleeding presents, and inhibitor titer eradication through immunosuppressants drugs. With the present cases, we highlight the importance of considering acquired hemophilia A in older patients with similar symptoms, to achieve early diagnosis and treatment.

The predictivity of the -alert performance- functionality of the OECD QSAR-Toolbox (c/w further issues on the predictivity of nonclinical testing).

The OECD QSAR-Toolbox can be considered a milestone in predictive toxicology. Because of the reliability of its supporting institutions (OECD and ECHA), its broadness in terms of feeder databases, and its predictive capacity, the QSAR-Toolbox is called to have a major role in regulatory toxicology. Recently, a novel functionality was built for the QSAR-Toolbox: the alert performance (AP). This prompted us to analyze the strengths, potentialities, and limitations of this new functionality, especially in the light of a pivotal framework recently discussed in the literature for the predictive use of nonclinical screening and testing. After meticulous analysis, and through some worked examples, high predictive capacity and applicability were found for the AP in both predictive and regulatory toxicology. For a specified chemical, the AP is useful in (a) anticipating its overall results in a given nonclinical test; (b) predicting its overall results regarding a selected toxicological endpoint in humans, and (c) facilitating post- to pre-test probabilities approaches that may support regulatory authorization for waiving the conduction of selected tests in laboratory animals. Furthermore, if a QSAR-Toolbox initiative is developed in or extended to pharmacology (e.g., safety pharmacology, drug abuse potential), it could represent another milestone; one that would give rise to the field of predictive pharmacology.

The 2-year rodent bioassay in drug and chemical carcinogenesis testing: Sensitivity, according to the framework of carcinogenic action.

The long-term rodent bioassay (RCB) has been the gold-standard for the pre-marketing prediction of chemical and drug carcinogenicity to humans. Nonetheless, the validity of this toxicity test has remained elusive for several decades. In the quest to uncover the performance of the RCB, its sensitivity (SEN) was charted as the first step. This appraisal was based on (a) chemicals with sufficient epidemiological evidence of carcinogenicity, and (b) other substances with limited epidemiological evidence, or remarkable classifications of carcinogenicity based on mechanistic or pharmacological data. In the present study, chemicals evaluated for their carcinogenicity to humans in IARC Monographs volumes 1-123, U.S. EPA IRIS Assessments, and U.S. NTP RoC were considered. This investigation gathered additional evidence supporting that, in hazard identification, the RCB is unwarranted for mutagenic or direct-acting genotoxicants. However, for purposes of risk assessment or management, the RCB might be justified whenever there is a lack of reliable and/or comprehensive epidemiological data. The RCB exhibited a significantly different SEN for threshold-based human carcinogens compared to non-threshold-based ones. With threshold-based chemicals, to increase the SEN of the testing from 80% (rat-RCB) to 90%, the 2-species RCB might be warranted. Nevertheless, the resolve would depend on the viewpoint, and on the future analysis of the overall performance of the RCB. In terms of SEN, and cancer hazard identification, the comparison between the RCB and alternative methods (e.g. rasH2 mouse, Tg.AC mouse) is now enabled.

Drug excipients, food additives, and cosmetic ingredients probably not carcinogenic to humans reveal a functional specificity for the 2-year rodent bioassay.

Regarding carcinogenicity testing, the long-term rodent bioassay (RCB) has been the test required by most regulatory agencies across the world. Nonetheless, due to the lack of knowledge about its specificity, it has been argued that the RCB is unspecific or even invalid. Because of the substantial limitations of epidemiology to identify chemicals probably not carcinogenic to humans (PNCH), it has been very difficult to address the specificity of the RCB. Nevertheless, because mechanistic/pharmacological data are currently recognized as a valid stream of evidence for the identification of chemical hazards, the road is now open to gain insight into the specificity of the RCB. Based on sound mechanistic/pharmacological data that support the classification of chemicals as PNCH, 100 PNCH substances were gathered in this investigation. Contrary to what was previously forecast, in this study, the RCB exhibited a functional specificity that ranged from 83% to 91%, depending on the settings of the testing (2-species vs. rats only, and the nominal maximum tolerated dose). Other contributions of this work were: (a) enabling the comparison, in terms of specificity, between the RCB and the alternative methods that could replace it (eg, Tg.AC mouse, rasH2 mouse); (b) disclosing what the specificity is for alternative methods that were developed using the RCB as the reference standard; and (c) expanding the previous narrow (only seven substances) set of chemicals identified as not likely to be carcinogenic to humans by hazard identification programs.

The first homozygous family for prothrombin G20210A polymorphism reported in Latin America.

The 20210A allele of the prothrombin gene is associated with increased risk of venous thromboembolism. In this study, we described manifestations of thrombosis in four generations of a Colombian family, with four 20210A homozygous carriers and six 20210G/A heterozygous carriers for polymorphism as well as unrelated participants from the same population. The levels of prothrombin in the 20210A homozygote patients were higher than in the normal 20210G homozygotes (133 + 11% and 92.3 + 12.4%, respectively, P < .01) and the 20210G/A heterozygotes (133 + 11% vs. 114.8 + 24%, P < .05). About 2 out of 4 20210A homozygotes and 5 out of 6 20210G/A heterozygous members of this family did not have venous thromboembolism or any other thrombotic manifestation even though one of them had been exposed to thrombotic risk factors. Thus, we posit the effect of 20210A on the thrombotic phenotype in this family seems to be weak.

Transfusiones en pacientes con pruebas de compatibilidad positivas y en aquellos con anemia hemolítica autoinmune / Approach to transfusion support in patients with positive compatibility test and in those with autoinmune hemolytic anemia

Es frecuente la presencia de pruebas de compatibilidad positivas en pacientes que requieren soporte transfusional. Los pacientes con anemia hemolítica autoinmune presentan autoanticuerpos calientes o fríos que reaccionan contra antígenos de los eritrocitos y producen reacciones hemolíticas, que pueden ir desde leves hasta graves. Los pacientes multitransfundidos o con insuficiencia renal crónica o con anemia de células falciformes, presentan aloanticuerpos que dificultan el tratamiento con derivados de la sangre. La frecuencia de los mismos es hasta de 32 por cientos en algunas series. Dado el perfeccionamiento de las técnicas de laboratorio, en la actualidad son posibles la detección y determinación de la especificidad de los autoanticuerpos y aloanticuerpos; el enfoque integral del paciente y el conocimiento de dichas técnicas son los mejores fundamentos para un soporte transfusional seguro.

Positive compatibility tests in patients who need blood transfusions are common. Patients with autoimmune hemolytic anemia may have warm or cool autoantibodies that react with red blood cell antigens and produce hemolytic transfusion reactions. Multitransfused patients, and those with either chronic renal disease or sickle cell disease, have alloantibodies that make blood transfusion difficult. In some series the frequency of such antibodies is as high as 32%. Detection and determination of specificity of auto antibodies and alloantibodies are now possible because of technical developments in laboratory. An integralapproach to patients and the knowledge of these procedures are the best bases to offer secure blood transfusions

Paciente con deficiencia de proteína C y múltiples trombosis: reporte de caso / A patient with C protein deficiency and multiple thromboses. Case report

Se debe considerar un estado de hipercoagulabilidad primaria o trombofilia heredada en los pacientes con enfermedad tromboembólica venosa. La sospecha clínica se debe dirigir a los pacientes con presentación temprana, recurrente, familiar o en sitios anatómicos poco usuales. En este reporte se describe el caso de un paciente con déficit de proteína C de la coagulación, quien desarrolló trombosis venosa profunda del miembro inferior derecho a los 36 años y un año después, trombosis venosa profunda del miembro inferior izquierdo. A la edad de 51 años presentó trombosis de vasos mesentéricos que condujo a una resección intestinal extensa lo que obligó a un trasplante de intestino delgado. Su padre había presentado trombosis venosa de los miembros inferiores. Se descartó la presencia asociada de la mutación G20210A de la protrombina y del Factor V Leiden. Hasta donde sabemos, es el primer caso de deficiencia de proteína C de la coagulación informado en la literatura colombiana.

Inherited thrombophilias are an important group of diseases that should be taken into account in the study of patients with thromboembolic disease, particularly in those whose clinical presentation includes frequent and recurrent thrombotic episodes at young age, in unusual sites, and a familial history of thrombosis. We report the case of a patient with C protein deficiency which developed deep venous thromboses of both legs when he was 36 and 37 years old. At 51 years of age he suffered from mesenteric thrombosis requiring surgical treatment and small intestine transplantation. His father had deep venous thrombosis. This is the first report of C protein deficiency in the Colombian literature. Other inherited thrombophilias such as the G20210A mutation in the prothrombin gene and Factor V Leiden were absent.

Uso clínico de los factores de crecimiento hematopoyéticos / Clinical use of hematopoyetic growth factor

Los factores de crecimiento hematopoyético {FCH) son producto de la excitante y prometedora industria de la biología molecular y la Ingeniería genética. Se hace una revisión de la farmacología del Factor Estimulador de Colonias de Granulocitos y del Factor Estimulador de Colonias de Granulocitos-Macrófagos, como también de su uso clínico en neutropenia aguda post-quimioterapia mielotóxica anticancerosa, trasplante de médula ósea, leucemia aguda, síndromes mielodisplásicos, anemia aplástica, síndrome de inmunodeficiencia adquirida y neutropenia crónica.

Hematopoietic growth factors are one of the products of the exciting and promising molecular biology and genetic engineering industries. Two of these factors are the recombinant human - granulocyte colony-stimulating factor and the recombinant human-granulocyte-macrophage colony-stimulating factor; a review Is presented on their pharmacology and clinical uses in acute neutropenia after myelotoxic anticancer therapy, bone marrow transplantion, acute leukemia, myelodyplastic syndromes, aplastic anemia, AIDS and chronic neutropenia

Significado clínico y fisiopatológico del eosinófilo / Clinical and physiopathological significance of the eosinophil

El eosinófilo es una célula con funciones protectoras y beneficiosas específicas pero que en algunas circunstancias Interviene como mediador en diferentes procesos fisiopatológicos. Un recuento aumentado en la sangre periférica (mayor de 500 células/mm cúbico) siempre debe investigarse porque puede ser el Indicador precoz de una enfermedad o la guía para llegar a un diagnóstico.