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Mario Blanco

Publications and source records attributed to Mario Blanco.

10 recordsLinked to original sources
PubMed2006

Secondary organic aerosol formation by heterogeneous reactions of aldehydes and ketones: a quantum mechanical study.

Experimental studies have provided convincing evidence that aerosol-phase heterogeneous chemical reactions (possibly acid-catalyzed) are involved to some extent in the formation of secondary organic aerosol (SOA). We present a stepwise procedure to determine physical properties such as heats of formation, standard entropies, Gibbs free energies of formation, and solvation energies from quantum mechanics (QM), for various short-chain aldehydes and ketones. We show that quantum mechanical gas-phase Gibbs free energies of formation compare reasonably well with the literature values with a root-mean-square (RMS) value of 1.83 kcal/mol for the selected compounds. These QM results are then used to determine the equilibrium constants (reported as log K) of aerosol-phase chemical reactions, including hydration reactions and aldol condensation for formaldehyde, acetaldehyde, acetone, butanal, hexanal, and glyoxal. Results are in qualitatively agreement with previous studies. In addition, the QM results for glyoxal reactions are consistent with experimental observations. To our knowledge, this is the first QM study that supports observations of atmospheric particle-phase reactions. Despite the significant uncertainties in the absolute values from the QM calculations, the results are potentially useful in determining the relative thermodynamic tendency for atmospheric aerosol-phase reactions.

Aerosols↗
PubMed2006

Conformational diversity of the Goodpasture antigen, the noncollagenous-1 domain of the alpha3 chain of collagen IV.

The noncollagenous-1 domain of the alpha3 chain of collagen IV networks of basement membranes is the target of an antibody-mediated inflammatory response in Goodpasture autoimmune disease. This domain when excised from basement membranes by bacterial collagenase digestion exists in two molecular forms, M(H) and M(L), that differ in cleavage site and mobility in SDS-PAGE. In the present study, M(H) and M(L) were shown to also differ with respect to epitope exposure, susceptibility to endoprotease digestion, and redox states of specific cystene residues, as determined by MS. Moreover, M(H) and M(L) assemble to form different quaternary structures, critically influencing pathogenic epitope(s) exposure and autoantibody binding. Collectively, our findings reveal that M(H) and M(L) are conformational isomers stabilized by a distinct disulfide bond connectivity, and coexist in basement membranes. The hitherto unrecognized conformational diversification of the Goodpasture autoantigen may be of relevance in pathogenesis.

Animals↗
PubMed2005

Synthesis of and structural studies on repeating sequences of abductin.

Little data exist on the structure and function of compressible elastomeric proteins such as abductin. An understanding of the underlying structural features of these proteins may lead to the development of a new class of highly tailored "compressible" hydrogels. To that effect, in this work, the structure of abductin was investigated by means of studies on several synthetic peptides corresponding to the most frequent sequences of abductin. In particular, the 10 amino acid abductin peptide sequence FGGMGGGNAG, tandem repeated in the protein, and two related 25 and 40 amino acid polypeptides were synthesized. These peptides were studied with regard to secondary structure, self-assembly, and polymer morphology. The results obtained with these peptides allow us to propose a preliminary structure-elasticity relationship for abductin not dissimilar from that currently accepted for elastin.A possible mechanism of elasticity relating abductin to elastin.

Circular Dichroism↗
PubMed2005

Adenoid cystic carcinoma arising in a fibroadenoma.

Adenoid cystic carcinoma (ACC) of the breast is a rare neoplasm, accounting for only 0.1 % of all breast carcinomas. An intriguing factor of ACC in the breast is its good prognosis compared to ACC in other locations, mainly in the minor salivary glands. The incidence of axillary lymph node involvement is also very low compared to that of other breast tumors, and distant metastases are uncommon. We report the case of a 65-year-old woman with a 2-year history of a well-circumscribed breast nodule sonographically thought to be a lymph node which was later excised because of rapid growth. Histologic examination showed an adenoid cystic carcinoma with squamous differentiation originating in a fibroadenoma. A review of the literature reveals no previous report of such a case.

Biomarkers, Tumor↗
PubMed2004

Thermodynamic properties of multifunctional oxygenates in atmospheric aerosols from quantum mechanics and molecular dynamics: dicarboxylic acids.

Ambient particulate matter contains polar multifunctional oxygenates that partition between the vapor and aerosol phases. Vapor pressure predictions are required to determine the gas-particle partitioning of such organic compounds. We present here a method based on atomistic simulations combined with the Clausius-Clapeyron equation to predict the liquid vapor pressure, enthalpies of vaporization, and heats of sublimation of atmospheric organic compounds. The resulting temperature-dependent vapor pressure equation is a function of the heat of vaporization at the normal boiling point [deltaHvap(Tb)], normal boiling point (Tb), and the change in heat capacity (liquid to gas) of the compound upon phase change [deltaCp(Tb)]. We show that heats of vaporization can be estimated from calculated cohesive energy densities (CED) of the pure compound obtained from multiple sampling molecular dynamics. The simulation method (CED) uses a generic force field (Dreiding) and molecular models with atomic charges determined from quantum mechanics. The heats of vaporization of five dicarboxylic acids [malonic (C3), succinic (C4), glutaric (C5), adipic (C6), and pimelic (C7)] are calculated at 500 K. Results are in agreement with experimental values with an averaged error of about 4%. The corresponding heats of sublimation at 298 K are also predicted using molecular simulations. Vapor pressures of the five dicarboxylic acids are also predicted using the derived Clausius-Clapeyron equation. Predicted liquid vapor pressures agree well with available literature data with an averaged error of 29%, while the predicted solid vapor pressures at ambient temperature differ considerably from a recent study by Bilde et al. (Environ. Sci. Technol. 2003, 37, 1371-1378) (an average of 70%). The difference is attributed to the linear dependence assumption thatwe used in the derived Clausius-Clapeyron equation.

Aerosols↗
PubMed2004

Muscarinic M3 acetylcholine receptor immunostaining in paraffin-embedded normal and neoplastic prostatic gland tissue.

Recent in vitro studies suggest that muscarinic receptors are important indicators of prostatic epithelial differentiation. Using choline in the mapping of prostatic lesions, radiographic studies have been interpreted as showing malignant transformation when high levels of receptors are found, but to our knowledge no correlation with the grade of prostatic cancer has been reported. To demonstrate the relationship of muscarinic receptors to differentiation, we immunostained normal and neoplastic prostatic tissue with antibodies that recognize receptors of acetylcholine, dividing the neoplastic tissue into two groups according to grade of differentiation. As far as we know, this is the first time that immunostaining of benign and neoplastic prostatic gland tissue with cholinergic receptors has been reported. Thirty-five cases of prostatic carcinoma were retrieved from our files and subdivided into two groups; a well to moderately differentiated group and a poorly differentiated group. Both groups were immunostained with M3 muscarinic receptor, along with a proliferation marker (Ki-67). The proliferating index measured with Ki-67 in the well to moderately differentiated group was low (<5% of the cells) and high in the poorly differentiated group (>20% of the cells). A strong correlation was observed between the strength of expression of the muscarinic M3 receptor and the differentiation of the lesion. The 18 cases of well to moderately differentiated carcinoma showed a mean staining intensity of approximately 1 with no case showing an intensity grade greater than 2. Normal controls along with normal peritumoral prostatic tissue also demonstrated a staining intensity of approximately 1. However, none of the 11 cases of poorly differentiated carcinoma showed staining. Our conclusion is that the presence of muscarinic acetylcholine receptor M3 by immunostaining distinguishes normal glandular epithelium and low-grade carcinomas from poorly differentiated tumors, which suggests that its demonstration in vivo could be a useful tool in distinguishing grade of tumor clinically.

Adenocarcinoma↗
PubMed2003

Chronic sclerosing sialadenitis (Kuttner's tumor): unusual presentation with bilateral involvement of major and minor salivary glands.

In 1896 Kuttner reported four cases which he described as induration of the submandibular gland. Histologically, they showed chronic inflammation and fibrosis. Sporadic cases of this entity that have come to be known as Kuttner's tumor or chronic sclerosing sialadenitis of the submandibular gland and have been reported throughout the 20th century. This inflammatory tumor has been under-recognized, and awareness of its importance and probable immunologic background have recently become evident. We report an unusual case of chronic sclerosing sialadenitis, affecting both parotid glands, both submandibular glands, and minor salivary glands of the oral cavity, and explore the immunohistochemical profile of this entity.

Antigens, CD↗
PubMed2002

Necrotizing granulomas in B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma.

We present three cases of patients with B-cell small lymphocytic lymphoma/chronic lymphocytic leukemia that were retrieved from our files during a period of 11 months and who suddenly developed lymphadenopathy. Clinically, this lymphadenopathy was thought to represent a manifestation of their background disease and, for this reason, no cultures were performed on fresh tissue. However, histologic studies in all cases showed necrotizing granulomas. When results of our special stains were negative, we submitted the specimens for molecular studies, which demonstrated the presence of tuberculous bacilli in two out of three cases. We believe that tuberculosis can present as a sudden lymphadenopathy in immunocompromised people and we would like to raise the awareness among the clinicians and nursing and pathology laboratory staff about the risks of handling these specimens without proper precautions. Also, we emphasize the fact that, in some cases, tuberculous bacilli cases may need molecular studies to be demonstrated.

Aged↗
PubMed1996

Metoclopramide-Induced Vascular Hyperreactivity: A Comparative Study Between Normotensive and Hypertensive Subjects.

In the present study, we have evaluated the cardiovascular responses to the cold pressor test (CPT) under intravenous metoclopramide (MTC) treatment (7.5 &mgr;g kg(minus sign1) min(minus sign1)) during a 30-min period and two additional periods, before and after MTC by using 5% glucose solution. There was a vascular hyperreactivity induced by MTC, Delta mm Hg was 21.4/24/1 mm Hg (systolic/diastolic blood pressure [BP]) during MTC versus Delta 17.2/17.9 mm Hg during 5% glucose infusion. In nine hypertensive subjects, Delta mm Hg was 36.8/25.7 during MTC versus Delta 31/24 mm Hg during 5% glucose. Bromocriptine pretreatment (7.5 mg daily for 7 days) antagonized MTC-BP increase during CPT. We conclude the following: (1) MTC induces a greater BP response during CPT which is blocked by using bromocriptine, a known DA(2) dopaminergic agonist. (2) A dopaminergic influence is present during CPT in normotensive and hypertensive subjects.

Journal Article↗