Molecular Bases of Protein Antigenicity and Determinants of Immunogenicity, Anergy, and Mitogenicity.

BACKGROUND: The immune system is able to recognize substances that originate from inside or outside the body and are potentially harmful. Foreign substances that bind to immune system components exhibit antigenicity and are defined as antigens. The antigens exhibiting immunogenicity can induce innate or adaptive immune responses and give rise to humoral or cell-mediated immunity. The antigens exhibiting mitogenicity can cross-link cell membrane receptors on B and T lymphocytes leading to cell proliferation. All antigens vary greatly in physicochemical features such as biochemical nature, structural complexity, molecular size, foreignness, solubility, and so on. OBJECTIVE: Thus, this review aims to describe the molecular bases of protein-antigenicity and those molecular bases that lead to an immune response, lymphocyte proliferation, or unresponsiveness. CONCLUSION: The epitopes of an antigen are located in surface areas; they are about 880-3,300 Da in size. They are protein, carbohydrate, or lipid in nature. Soluble antigens are smaller than 1 nm and are endocytosed less efficiently than particulate antigens. The more the structural complexity of an antigen increases, the more the antigenicity increases due to the number and variety of epitopes. The smallest immunogens are about 4,000-10,000 Da in size. The more phylogenetically distant immunogens are from the immunogen-recipient, the more immunogenicity increases. Antigens that are immunogens can trigger an innate or adaptive immune response. The innate response is induced by antigens that are pathogen-associated molecular patterns. Exogenous antigens, T Dependent or T Independent, induce humoral immunogenicity. TD protein-antigens require two epitopes, one sequential and one conformational to induce antibodies, whereas, TI non-protein-antigens require only one conformational epitope to induce low-affinity antibodies. Endogenous protein antigens require only one sequential epitope to induce cell-mediated immunogenicity.

Insights from Pharmaceutical Biotechnology into Phenolic Biopharmaceuticals against COVID-19.

BACKGROUND: The COVID-19 pandemic had infected more than 3.5M people around the world and more than 250K people died in 187 countries by May 2020. The causal agent of this disease is a coronavirus whose onset of symptoms to death range from 6 to 41 days with a median of 14 days. This period is dependent on several factors such as the presence of comorbidities, age and the efficiency of the innate or adaptive immune responses. METHODS: The effector mechanisms of both types of immune responses depend on the pathogen involved. In the case of a viral infection, the innate immune response may approach the harmful virus through pattern recognition receptors inducing an antiviral state. RESULTS: On the other hand, the adaptive immune response activates antibody production to neutralize or eliminate the virus. Phenolics are plant secondary metabolites with many biological activities for plants and humans against infection. Chemical modification of proteins may enhance their biological properties; thus, a protein of medical interest, for instance, a viral protein can be used as a scaffold to build a biopharmaceutical conjugated or complexated with phenolics exhibiting structural complexity or biological activities to achieve effective phenolic-protein-based therapeutics like vaccine adjuvant complexes, immunogen conjugates, and antiviral conjugates. CONCLUSION: Pharmaceutical biotechnology applies the principles of biotechnology to develop biopharmaceuticals for protein-based therapeutics; such as adjuvants, recombinant proteins, monoclonal antibodies, and antivirals. As neither a vaccine nor a treatment for COVID-19 is currently available, this manuscript focuses on insights from pharmaceutical biotechnology into phenolic biopharmaceuticals against COVID-19.

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.

Estudio morfométrico de la arteria radial y su implicación en la cirugía de revascularización miocárdica / Morphometric study of the radial artery and its involvement in bypass surgery grafting

La arteria radial (AR) es utilizada en la práctica médica para la realización de diversos procedimientos quirúrgicos, entre los que destaca la cirugía de revascularización miocárdica. En la literatura actual hay poca información acerca de la compatibilidad de esta arteria con otros conductos vasculares. El objetivo fue determinar las características anatómicas, morfométricas y distribución de la arteria radial en el antebrazo. Se disecó la arteria radial de 10 antebrazos de cadáveres embalsamados; se identificaron y registraron los ramos musculares y vasa nervorum emitidos por la arteria, se midió la longitud total y obtuvieron tres muestras (proximal, media y distal) de cada una para ser procesadas mediante técnicas histológicas y se determinaron los grosores de la túnica media y los diámetros. Se observaron modas de 8 ramos arteriales para el músculo braquiorradial, 4 para los músculos flexor superficial de los dedos y flexor radial del carpo, un ramo arterial único para el músculo pronador cuadrado y una moda de 1 vasa nervorum para el ramo superficial del nervio radial. La longitud total de la arteria fue de 21,94 cm (+/-3,34). Los grosores encontrados fueron de 196,16 µm (+/-72,35), 148,25 µm (+/-40,40) y 158,96 µm (+/-45,74) en los segmentos proximal, medio y distal respectivamente. Los diámetros luminales mostraron una media de 1,48 mm (+/-0,70) en la región proximal, 1,01mm (+/-0,35) en la media y 1,43 mm (+/-0,47) en la distal. Considerando las características morfométricas, la arteria radial es una opción que satisface los criterios de longitud, diámetro luminal y grosor para ser utilizada como injerto.

The radial artery (RA) is used in medical practiceto performdifferentsurgical procedures, of which most realized is the coronary artery bypass graftsurgery. In the current literature there is little information about the compatibility of this artery with other vascular conduits. Therefore the aim of this study was to determine the anatomical, morphometric and distribution characteristics of radial artery on the forearm. Radial artery was dissected from the forearms of 10 embalmed cadavers, muscular branches and vasa nervorum were identified and registered, total length was measured. Three samples of each artery were obtained(proximal, middle and distal) to be processedby histological techniques and to determinethe thickness of its tunica mediaand its diameters. The results show a mode of 8 arterial branches to the brachioradialis, a mode of 4 for thesuperficial flexor muscles of the fingers and flexor carpi radialis, we found an unique arterial branch to the pronator quadratus and a mode of 1 vasa nervorum of superficial branch of radial nerve. The total length of the artery was 21.94 cm (+/- 3.34). The vascular wall thickness we found were 196.16 mm (+/-72.35), 148.25 mm (+/-40.40) and 158.96 mm (+/-45.74) in the proximal, middleand distal segments respectively. The luminal diameters showed an average of 1.48 mm (+/-0.70) in the proximal region, 1.01 mm (+/-0.35) in the middle region and 1.43 mm (+/-0.47) in the distal region. In the present study we concludedthat considering the morphometric characteristics, the radial artery is an option that satisfied the criteria of length, thickness and luminal diameterto be used as a graft in the coronary artery bypass graft surgery.

Morphometric Study of Cervical Vertebrae C3-C7 in a Population from Northeastern Mexico / Estudio Morfométrico de las Vértebras Cervicales C3-C7 en una Población del Noreste de México

Knowing the dimensions of the vertebral elements is very important for the development of instrumentation related to the cervical spine. Ethnic variations have been reported in these dimensions and, to date, there have been no morphometric studies of this area performed on the Mexican population. We conducted a morphometric study of 150 cervical vertebrae (C3-C7) obtained from a northeastern Mexican population to determine the dimensions of the bodies, pedicles, laminae, spinous processes, and superior and inferior articular processes. We did not find significant differences (p<0.05) in measurements taken of the left and right sides. The dimensions of the vertebral bodies were larger at lower levels. The pedicles of the C3 vertebra were larger in all dimensions compared to the other vertebrae. The largest height of the laminae was observed at C7 and the largest transverse length was observed at C5. The dimensions of the bodies, spinous processes, and laminae increased from C3-C7, whereas the dimensions of the pedicles and superior and inferior articular process height decreased toward the lower cervical levels.

Las mediciones de los elementos vertebrales son importantes para la instrumentación de columna cervical. Se han reportado variaciones étnicas en estas medidas y en la actualidad no existen estudios morfométricos en la población mexicana. Se realizó un estudio morfométrico en 150 vértebras cervicales (C3-C7) para determinar las medidas de los cuerpos, pedículos, láminas, procesos espinosos y articulares superiores e inferiores. No se encontraron diferencias significativas (p<0.05) en las medidas tomadas entre ambos lados. Las dimensiones de los cuerpos vertebrales se incrementan en niveles más bajos. Los pedículos de la vértebra C3 son mayores en todas sus dimensiones. La mayor altura de las láminas se observó en C7 y la mayor longitud transversal en C5. Las dimensiones del cuerpo, procesos espinosos y láminas se incrementan de C3-C7, mientras las dimensiones de los pedículos, altura de procesos articulares superiores e inferiores disminuyen en los niveles cervicales más bajos.

[Study of the vascular morphology of the lower limb nerves used as grafts]. / Estudio de la morfología vascular en los nervios de la extremidad inferior utilizados como injertos.

INTRODUCTION: The placement of a vascularized nervous graft is an option for acute nervous injuries treatment, as this has demonstrated a longer viability. OBJECTIVE: To carry out a macroscopic and microscopic analysis of the vascularity of the main lower limb nerves used as vascularized nervous grafts. MATERIALS AND METHODS: It was followed out a descriptive, transversal and non-comparative study to analyse the saphenous, the sural, the deep peroneal and the superficial peroneal nerves vascularity. This study was performed in two stages: 1) an in situ vascularity study and 2) a morphometric study. RESULTS: By the in situ study, it was demonstrated the following: the total length of the lower limb nerves used as graft, was in a decrease order: sural nerve (micro = 29.26 cm, +/- 4.05 cm), superficial peroneal nerve (micro = 28.61 cm, +/- 3.97 cm), deep peroneal nerve (micro = 26.64 cm, +/- 5.21 cm) and saphenous nerve (micro = 25.12 cm, +/- 4.42 cm). The morphometric study demonstrated that the dominant artery with the major diameter belongs to the saphenous nerve, with a diameter of 1.13 mm; then we have the superficial peroneal nerve with a 1.01 mm diameter, followed by the deep peroneal nerve with 0.91 mm, and finally the sural nerve with the smallest diameter, 0.85 mm. CONCLUSIONS: The saphenous nerve has the most appropriated morphological characteristics to be used as a vascularized graft; by the contrary the deep peroneal nerve represents the last option from all the nerves included in this study.