Three-dimensional printing in healthcare / Impresión 3D en cuidado de la salud

ABSTRACT This work aims to briefly present the cutting edge of 3D printing innovation in healthcare. This technology is used for surgical planning, medical education, bioprinting of tissues, and medical equipment spare parts in fields like pharmacology, prosthetics, surgery, and regenerative medicine. A review of the last decade was made in the search engines of PubMed and Espacenet. Three authors reviewed titles, abstracts, and keywords separately to identify studies appropriate to the topic. After the initial examination, complete texts of identified relevant studies were obtained and classified according to the authors. Results were synthesized in a narrative literature review. The revision showed that 3D printing has become of common use in the healthcare system since it allows medical personnel to implement customized solutions for each patient, thus reducing the probability of a false diagnostic or treatment. Major applications among the advantages and disadvantages of 3D printing in healthcare were presented. Nowadays, the main challenge in 3D printing is the cost of the equipment and its manufacturing. In the future, the challenges in cost could be reduced, but processing requirements and limited materials may still need further work.

RESUMEN Este artículo pretende mostrar breve y rápidamente la vanguardia del empleo de la impresión 3D en salud. La impresión 3D se utiliza para planificación quirúrgica, educación médica, bioimpresión de tejidos e impresión de repuestos de equipos médicos en campos como farmacología, prótesis, cirugía, ingeniería de tejidos y medicina regenerativa. Se realizó una revisión de publicaciones en la última década en los motores de búsqueda PubMed y Espacenet. Tres autores examinaron de forma independiente títulos y resúmenes para identificar estudios relevantes. Se obtuvieron los textos completos y se clasificaron de acuerdo con todos los autores. Los resultados se sintetizaron en una revisión narrativa de la literatura. La revisión mostró que la impresión 3D se ha vuelto de uso común en el sistema de atención médica, ya que permite al personal médico implementar soluciones personalizadas para cada paciente, lo que reduce la probabilidad de un diagnóstico o tratamiento falso. Se presentaron las principales aplicaciones, así como ventajas y desventajas de la impresión 3D en salud. Hoy en día, el principal desafío en la impresión 3D es el costo del equipo y su fabricación. En el futuro, los desafíos en costos podrían reducirse, pero los desafíos de procesamiento y materiales requieren mayor desarrollo.

Case report: cutaneous penicilliosis due to Penicillium chrysogenum.

A case of cutaneous penicilliosis in a young man, without immunological compromise is reported. The lesions in the neck were characterized by two exudative reddish-purple pruriginous and painless spots. Penicilliosis was diagnosed after serial laboratory studies based on the observation of hyphae by direct microscopic examination and histopathology. Cultures of the tissue obtained from the lesions, developed mould colonies with typical conidia of Penicillium chrysogenum, which was thermotolerant at 37 degrees C. The treatment with itraconazole was successful, and 15 days after cessation of therapy, no recurrence of infection was observed. The epidemiology of this type of mycosis is commented upon, as well as the rarity of infections produced by Penicillium, even as opportunistic pathogens. The isolation of P. chrysogenum from skin lesions is exceptional.

Effect of phorbol myristate acetate (PMA) and ionophore A23187 on interleukin-2 levels and proliferation of activated T lymphocytes from patients with lepromatous leprosy.

The immunodeficiency present in patients with lepromatous leprosy is characterized by the limited proliferation of T lymphocytes, and is explained in part by the impaired synthesis of interleukin-2 (IL-2). Diacylglycerol (DAG) and calcium produce the activation of PKC, ERK and JNK kinases, implying a normal IL-2 response. Phorbol esters, such as PMA, can substitute for DAG and are mitogenic to human T and B cells activating several cytokine-encoding genes. Ionophore A23187 increases calcium permeability across the cellular membrane to the cytosol of lymphoid cells and is considered a co-mitogen of T lymphocytes. Here we report that: 1) PHA-activated T lymphocytes from LL patients can be separated in vitro into two groups: a) responders (R) with a stimulation index (SI) of > 10 and (b) nonresponders (NR) with a SI of < 10. 2) The proliferative responses of cells from LL(R), LL(NR) and normal subjects were measured after being stimulated with: I, PHA, PMA, PMA + I PHA + PMA and PHA + PMA + ionophore (PPI). The most important result occurs in LL(NR) patients whose cells did not respond to PHA stimulation but increased to normal levels of proliferation when they were stimulated with PMA. Furthermore, the three groups, (NR, R and normals) strongly increased their responses when they were incubated with PPi. 3) Finally, Il-2 concentrations in the supernatants of cultures of T lymphocytes from LL(NR), LL(R) and controls were relatively low when they were incubated with PHA or PMA, but the addition of ionophore to PMA and the combination of PHA + PMA strongly increased the production of IL-2 in all of them, reaching the optimum IL-2 concentration when PPI is used. It can be concluded that the use of PMA, analogous to DAG, and ionophore A23187 (calcium increaser) in cultures of mitogen-activated T lymphocytes from LL patients induced the expression of the IL-2 gene, thus correcting the inadequate proliferation of T cells from LL patients.

Hereditary multiple benign cystic epithelioma (multiple trichoepithelioma) with onset at early age.

A mother and a daughter affected with multiple trichoepithelioma were studied. The age of onset of the symptomatology in both was 7-years-old, the daughter being more severely affected than the mother at this age. This early age of onset is an exceptional observation which could be explained by maternal imprinting.

[Effect of potassium iodide on the immune response in the sporotrichosis.]. / Efecto del yoduro de potasio sobre la respuesta inmune en la esporotricosis.

Potassium iodide (KI), the specific treatment for sporotrichosis, apparently does not have a direct action on Sporothrix schenckii. The spontaneous healing and the variability of the clinical presentation in the disease have strengthened the idea that the KI rather interacts with the immune response of the host. The phagocytic process is inefficient in individuals with sporotrichosis in whom the microbicidal mechanism of halogenation fails to control the disease. There is evidence that blocking of free radicals decreases in the presence of KI. Humoral and cellular immunity are present in sporotrichosis but its participation is uncertain; it is yet to be determined if in this mycosis the KI influences other processes or factors of immune response.

Long-term survival of free fat grafts in muscle: an experimental study in rats.

In this study, we showed both macroscopically and microscopically the viability of the autotransplanted fat placed intramuscularly in long-term follow-up. The study was performed on 120 Wistar rats during a 12-month period. The fat grafts were obtained from either the inguinal region or preurinary bladder cavity. Rats were divided into six groups. In group 1, the fat was injected in thin rolls in the frontal subcutaneous layer. In group 2, the fat was injected in thin rolls in the gluteus superficialis, biceps femoris, gastrocnemius, and semitendinosus muscles. In group 3, 6 mm x 2 mm fat strips were placed subcutaneously in the frontal region. In group 4, the same dimension of fat strips were placed in the gluteus superficialis and biceps femoris muscles. In group 5, large cystic spaces of fat were injected subcutaneously in the frontal region, and in group 6, large cystic spaces of fat were injected intramuscularly. Rats at 3, 6, 9, and 12 months after fat grafting were sacrificed in order to carry out the macroscopic observations. The results showed clinical and microscopic success in groups 2 and 4, and problems and failure with the remaining groups.

Recognition of Mycobacterium leprae antigens with antibodies present in sera from patients with lepromatous leprosy.

A great diversity of antigens from Mycobacterium leprae have been described. One practical approach should be to utilize them as markers to indicate when a household contact is at risk of becoming infected and then moving to an active form of leprosy. For this purpose, sonic extracts of M. leprae were fractionated in 10% SDS-PAGE under reducing conditions. The fractionated proteins were then transferred to nitrocellulose sheets and incubated with sera from lepromatous leprosy cases, their contacts, and normal subjects in order to reveal the frequency of antigen recognition of each set of sera. The results showed that sera from lepromatous leprosy patients frequently recognized two proteins, one of approximately 28 kDa and the other of approximately 65 kDa, when compared with the sera from normal subjects. The contacts frequently recognized an approximately 16-kDa antigenic band, while sera from normal subjects recognized one protein of approximately 18 kDa. According to the results, the four recognized proteins from M. leprae can be considered markers of the above conditions (approximately 65 kDa, approximately 28 kDa for lepromatous leprosy, approximately 16 kDa for contacts, and approximately 19 kDa for normal subjects). From these, an easy serological test, such as an ELISA, can be developed to predict if a contact is moving toward lepromatous leprosy before detection of the actual clinical signs or symptoms.

Hyperkeratosis-hyperpigmentation syndrome: a confirmative case.

A 22-year-old female showing hyperpigmented spots and mild palmoplantar hyperkeratosis as leading features is presented. The diagnosis of Hyperkeratosis-hyperpigmentation syndrome, previously described by our group as an autosomal dominant trait, was unmistakable, thus permitting the corroboration of this genodermatosis.

Chromoblastomycosis caused by Exophiala spinifera.

Exophiala spinifera is reported as a newly recognized agent of chromoblastomycosis. This case demonstrates that infections caused by dematiaceous fungi may be variable and that a single fungus may cause more than one type of infection. Chromoblastomycosis and phaeohyphomycosis represent extremes of a continuum of infections.

Deficiency in the incorporation of labeled thymidine and inhibition in the biosynthesis of interleukin-2 in lymphocytes obtained from Histoplasma capsulatum infected mice.

The incorporation of (3H) thymidine and the biosynthesis of interleukin-2(IL-2) were investigated in Concanavalin A (ConA) and histoplasmin stimulated lymphocytes from spleen of infected Balb/c mice with the yeast phases of Histoplasma capsulatum. The ability to incorporate (3H) thymidine of Con A stimulated lymphocytes in culture from spleen of Histoplasma capsulatum infected mice, as well as the IL-2 content present in the supernatants of that cultures, were depressed along the first three weeks of the experiments, but starting week five, normal values were restored or even discretly increased. Incorporation of (3H) thymidine in histoplasmin stimulated lymphocytes remained inhibited along the seven weeks the experiment lasted. Results showed that inoculation of H. capsulatum yeast in mice provoked a temporary immunosuppression on cell mediated immunity, that can be explained by means of the inability of T cells to produce enough IL-2 necessary for the proliferation of T cells in culture.

[Formation of E-rosettes in homozygous nude mice (nu/nu) and heterozygotes (nu/+)]. / Formación de rosetas-E en ratones desnudos homocigotos (nu/nu) y heterocigotos (nu/+).

Nude homozygote nu/nu mice show a deficiency in their cellular immune response, due to the fact that their thymic tissue is very scarce. The purpose of this paper has been to determine whether nu/nu mice, in the presence of T lymphocytes, have the capacity of forming E rosettes with sheep erythrocytes. These mice do present them, although in significantly lower quantities when compared to the nu/+ and normal ones of Balb/c strain. This result confirms previous information which point towards the existence of other types of markers on the surface of T lymphocytes in nu/nu mice.

[Phagocytic activity in PMN leukocytes and macrophages of athymic nu/nu mice]. / Actividad fagocítica en leucocitos PMN y macrófagos de ratones atímicos nu/nu.

The athymic nu/nu mice represent a natural model for studying defense mechanisms. This study had the object of evaluating the phagocytic activity of polymorphonuclear leucocytes (PMN) and peritoneal macrophages (PM) in congenitally athymic homozygotic nu/nu mice. The results showed that the chemotaxis, random mobility, ingestion of latex particles and reduction of nitroblue tetrazolium were all normal. Nevertheless, the enzyme myeloperoxidase in the PMN was significantly diminished when compared with Balb/c mice. These results suggest a partial decrease in the oxidative metabolism of the PMN in nu/nu mice.

[Evaluation of immune response in experimental sporotrichosis using T and B lymphocyte count]. / Evaluación de la respuesta inmune en la esporotricosis experimental por el cuanteo de linfocitos T y B.

The effector cells of the immune response are involved in the clinical course of bacterial, viral and mycotic infections. Previous publications have reported that some mycotic infections, including sporotrichosis, can produce a negative modulation of the immune response unfavorable for the host. In this work T and B lymphocytes capable to form direct and indirect rosettes respectively with sheep erythrocytes in gerbils with experimental sporotrichosis, were measured. It was found a significant rise in the number to T and B lymphocytes which means normal immunological reactivity. These results are not in accordance with the idea that sporotrichosis can depress the immune response of the host.

[Leukocyte phagocytic activity in gerbils with experimental sporotrichosis treated with potassium iodide]. / Estudio de la actividad fagocítica de los leucocitos de gerbiles con esporotricosis experimental tratados con ioduro de potasio.

One effective treatment against sporotrichosis is the oral administration of potassium iodide (KI). It is not known how it works, and also it is not known if this substance has some effect on the microbicidal activity of polymorphonuclear neutrophils (PMN) and macrophages. In this work the phagocytic activity of gerbils treated with KI was studied. Gerbils cured within 62 days of treatment with KI, their PMN and macrophages showed an increased ability for reducing nitroblue-tetrazolium (NBT); myeloperoxidase activity was decreased in PMN. These results were the expected in any chronic infection and demonstrates that KI effectiveness on the experimental sporotrichosis works by an independent mechanism of phagocytosis.