SARS-CoV-2: what it is, how it acts, and how it manifests in imaging studies. / SARS-CoV-2: cómo es, cómo actúa y cómo se expresa en la imagen.

COVID-19 is a disease with many clinical, biochemical, and radiological signs that has a predilection for the lungs, probably because of the high number of ACE-2 receptors in this organ. The infection of cells activates proinflammatory substances, causing diffuse alveolar damage, which is the histopathological basis of ARDS. The exudative phase would manifest as ground-glass opacities and consolidation, and the proliferative phase would manifest as a tendency toward a more linear morphology. Both CT and PET/CT findings support the inflammatory character of the lung lesions in the initial phase of the disease and in patients with mild-moderate disease. Severe cases have pulmonary hypoperfusion that is likely due to abnormal alveolar ventilation and perfusion. On the other hand, a prothrombotic state increases the risk of thromboembolic disease through the activation of coagulation and platelet pathways with the production of fibrin degradation products (D-dimer) and consumption of platelets.

SARS-CoV-2: cómo es, cómo actúa y cómo se expresa en la imagen / SARS-CoV-2: what it is, how it acts, and how it manifests in imaging studies

La COVID-19 es una enfermedad con una gran semiología clínica, bioquímica y radiológica, que tiene una afectación preferente por el pulmón, probablemente debido a un mayor número de receptores ECA-2. La infección celular activa sustancias proinflamatorias y provoca un daño alveolar difuso, que es la base histopatológica del distrés respiratorio del adulto. La fase exudativa explicaría las imágenes "en vidrio deslustrado" y consolidación, mientras que la tendencia hacia una morfología más lineal representa la fase proliferativa. Tanto la tomografía computarizada (TC) como la tomografía por emisión de positrones/ tomografía computarizada (PET/TC) apoyan el carácter inflamatorio de las lesiones pulmonares cuando la enfermedad está en fase inicial o es leve-moderada. Los casos graves muestran una hipoperfusión pulmonar que se explicaría por una alteración de la ventilación-perfusión alveolar (V/Q). Por otro lado, un estado protrombótico conlleva mayor probabilidad de enfermedad tromboembólica por la activación de la vía de la coagulación y plaquetaria, con la producción de sustancia de degradación de la fibrina (dímero D) así como el consumo de plaquetas

COVID-19 is a disease with many clinical, biochemical, and radiological signs that has a predilection for the lungs, probably because of the high number of ACE-2 receptors in this organ. The infection of cells activates proinflammatory substances, causing diffuse alveolar damage, which is the histopathological basis of ARDS. The exudative phase would manifest as ground-glass opacities and consolidation, and the proliferative phase would manifest as a tendency toward a more linear morphology. Both CT and PET/CT findings support the inflammatory character of the lung lesions in the initial phase of the disease and in patients with mild-moderate disease. Severe cases have pulmonary hypoperfusion that is likely due to abnormal alveolar ventilation and perfusion. On the other hand, a prothrombotic state increases the risk of thromboembolic disease through the activation of coagulation and platelet pathways with the production of fibrin degradation products (D-dimer) and consumption of platelets

Imagen híbrida (SPECT/TC) en la evaluación y manejo de un paciente con calcificación heterotópica y prótesis de cadera / Hybrid image (SPECT/CT) in the evaluation and management of a patient with heterotopic calcification and hip prostheses

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Laser capture microdissection protocol for gene expression analysis in the brain.

Laser capture microdissection (LCM) allows the isolation of specific cell populations from complex tissues that can be then used for gene expression studies. However, there are no reproducible protocols to study RNA in the brain and, particularly, in the substantia nigra. RNA is a very labile biomolecule that is easily degraded during manipulation. LCM studies use low amounts of material and special precautions must be taken to preserve RNA yield and integrity, which are decisive for PCR analysis. The RNA yield and/or integrity can be affected negatively by tissue manipulation, LCM process and RNA extraction. We have optimized these three critical steps using nigral tissue sections, and developed a LCM protocol to obtain high-quality RNA for gene expression analysis. The optimal LCM protocol requires the use of 20 µm-thick tissue sections mounted on glass slides and processed for rapid tyrosine hydroxylase immunofluorescence. Additionally, a total microdissected tissue area of 1 mm2 and a column-based RNA extraction method were used to obtain a high RNA yield and integrity. In the rat substantia nigra, we demonstrated the expression of RNA for the angiotensin type 1 and type 2 receptors using this optimized LCM protocol. In conclusion, the LCM protocol reported here can be used to study the expression of both scarcely or abundantly expressed genes in the different brain regions of mammals under both physiological and pathological conditions.

Reissner's fibre proteins and p73 variations in the cerebrospinal fluid and subcommissural organ of hydrocephalic rat.

Reissner's fibre (RF) is formed by the polymerization of the glycoprotein secreted by the subcommissural organ (SCO). The SCO also secretes soluble glycoprotein into the cerebrospinal fluid (CSF); variations in RF and SCO have been reported in hydrocephalus. On the other hand, hydrocephalus and other brain alterations have been described in p73 mutant mice. The p73 belongs to the tumour suppressor p53 protein family and has two isoforms: the TAp73 with apoptotic activity and DeltaNp73 with anti-apoptotic function. Moreover, the TAp73 isoform is glycosylated and secreted into the CSF. In the present work, we analysed the variations in RF and p73 proteins in the CSF and SCO of spontaneously hydrocephalic rats. Brains from control rats and spontaneously hydrocephalic rats of 12 months of age were used. The SCO sections were immunohistochemically processed with anti-TAp73 and anti-Reissner fibre (AFRU). The spontaneous hydrocephalus presents a decrease in the AFRU immunoreactive material in the SCO and an absence of RF. The anti-TAp73 was also present, slightly decreased, in the hydrocephalic SCO. AFRU and p73 bands were also detected in the CSF by western blot and six AFRU and p73 protein bands of a similar molecular weight were found in the CSF of the control rats. The number of AFRU and p73 bands was lower in the hydrocephalic rats than in the control rats. In conclusion, hydrocephalus produces a decrease in the secretions of the SCO and an absence of RF and a decrease in p73 and RF proteins in the CSF.

Expression of certain proteins in the subfornical organ and cerebrospinal fluid of spontaneously hypertensive rats.

The objective of this study was to analyze the proteins in the cerebrospinal fluid of spontaneously hypertensive rats and to study their possible role in the relationship between hydrocephalus, arterial hypertension and variations in the subfornical organ. Brains and cerebrospinal fluid from control Wistar-Kyoto rats and spontaneously hypertensive rats sacrificed with chloral hydrate were used. Cerebrospinal fluid and extract of subfornical organ were processed by protein electrophoresis. Antisera against protein bands of 141, 117 and 48 kDa and Concanavalin A were used for immunohistochemical and western blot study of the subfornical organ, adjacent circumventricular structures and cerebrospinal fluid. Ventricular dilation in the spontaneously hypertensive rats and the presence of quite a lot of protein bands in the cerebrospinal fluid of the hypertensive rats, which were either not observed or scarcely present in the cerebrospinal fluid of the Wistar-Kyoto rats, were confirmed. The subfornical organ, third ventricle ependyma and choroideus plexus showed immunoreactive material for antibodies against 141kDa, 117 and 48 kDa proteins band (anti-B1, anti-B2 and anti-B3). The larger amount of the immunoreactive material was found in the subfornical organ of the spontaneously hypertensive rat. Our results and the alterations observed by other authors in the subfornical organ in hydrocephalic and hypertensive rats support the possibility that this circumventricular organ, some proteins of the cerebrospinal fluid and ventricular dilation could be connected with the physiopathology of this type of hypertension.

Alterations of the cerebrospinal fluid proteins and subcommissural organ secretion in the arterial hypertension and ventricular dilatation. A study in SHR rats.

The aim of this work was to analyze the proteins in the cerebrospinal fluid (CSF) of spontaneously hypertensive rats, to study their possible role in the relationship between hydrocephalus, arterial hypertension and alterations in the subcommissural organ. Brains from control Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) sacrificed with chloral hydrate were used. Antiserums against some cerebrospinal fluid protein bands and Reissner's fiber (RF) were used for immunohistochemical study of the SCO. Ventricular dilation was observed in the lateral and third ventricle of the SHR. Third ventricle ependyma showed immunoreactive material (IRM) for antibody against 141 kDa protein band anti-B1 and 117 protein band anti-B2 and the SCO of the SHR showed a decrease of the IRM when compared with WKY rats. An alteration in the expression of anti-RF was found to compare the SCO of the WKY and SHR groups. Our results demonstrate that hydrocephalus and hypertension are interconnected in this kind of rat which produce alterations in SCO secretions and some proteins of the CSF.

[Hodgkin's disease in small children (author's transl)]. / La enfermedad de Hodgkin en el niño en edad preescolar

17 cases of Hodgkin's disease are reported, seen in a ten year period. Age of patients oscillated between three and seven years. There was a predominance of mixed cellularity type in histologic pattern. Most of patients were diagnosed in advanced clinical stages. Primary sign of disease was presence of cervical adenopathies and there were few cases of thoracic disease. Treatment consisted in radiotherapy and chemotherapy, according to histological type and clinical stage. Survival in our serie is of 53.3% with periods of observation from six months to seven years.

[Long term evolution in Blackfan-Diamond hypoplastic anemia (author's transl)]. / Evolución a largo plazo en la anemia hipoplásica tipo Blackfan-Diamond

Six cases of Blackfan-Diamond hypoplastic anemia are reported. Five were initiated within six months of life. All cases showed intense anemia, severe reticulopenia and hypersideremia. Two of them had associated malformations. Treatment was established with Dexametasone at high doses, followed by a maintenance treatment at lower doses. A partial response was obtained in all cases. Treatment with deforroxiamine was used in order to paliate hemosiderosis. Two cases developped microangiopathic hemolitic anemia; relations with primary disease could not be determined.