Histomorphological, Histochemical and Ultrastructural Studies on the Healthy Liver of Yemen Veiled Chameleon (Chamaeleo calyptratus) in Southern Saudi Arabia / Estudios Histomorfológicos, Histoquímicos y Ultraestructurales en el Hígado Sano del Camaleón Velado de Yemen (Chamaeleo calyptratus) en el Sur de Arabia Saudita

SUMMARY: The livers of reptiles are being studied as a model for the link between the environment and hepatic tissue. There have been few investigations on the histology of reptile livers, and very few or no studies have examined the histology of liver of veiled chameleon (Chamaeleo calyptratus). This paper describes the histomorphological, histochemical and ultrastructural characterization of the liver of veiled chameleons in southern Saudi Arabia. Seven Chamaeleo calyptratus were captured in the summer season in Abha City, Aseer region, southern Saudi Arabia. Chamaeleon liver samples were processed for histomorphology, histochemistry and ultrastructure analyses. Morphologically liver of Chamaeleo calyptratus was observed as a large dark brown organ with lighter speckles, which represent melanin deposits. It located at the ventral part of abdominal cavity forward of the stomach. Its dimensions approximately were 3.7 x 2 cm. The liver was a bilobed organ divided into two lobes, right and left lobes. The right one was bigger than the others. The gallbladder was well developed and had an elongated shape, situated between the two lobes and contained the bile for the digestion. Microscopically, the liver was found to be covered by a thick layer of connective tissue, which formed the hepatic capsule. Hepatic parenchyma probably appeared in cross sections as hepatic glandular-like alveoli "acini" or follicular structures with various diameters, each acinus contains approximately four to six hepatocytes, surrounded by sinusoidal capillaries filled with abundant melanomacrophages, which are absent in birds and mammals. Melanomacrophages are common in the hepatic parenchyma's perisinusoidal areas, particularly near portal spaces. Hepatocytes are polyhedral or pyramidal with and mostly contained large, rounded nuclei mostly peripherally located, with prominent dark oval nucleoli. Some of nuclei are eccentric or central position. The cytoplasm appeared spongy or vacuolated and more eosinophilic when stained by hematoxylin-eosin and strongly reactive to PAS staining technique, indicating abundant glycogen content. The reticular fibers that surround hepatocytes, blood arteries, and sinusoids supported the hepatic parenchyma. The blood sinusoids are seen interspersed among hepatocytes of varying sizes. The sinusoidal lumen was bordered by flattened endothelial cells and includes elliptical nucleated erythrocytes and liver macrophages as phagocytes, which are also known as Kupffer cells. Branches of the portal vein, hepatic artery, small bile duct, and lymph vessels were detected in the hepatic portal area "tract" or triad which made up of connective. Hematopoietic tissue was observed in subcapsular region and portal triads. Ultrastructurally, the hepatocyte appeared polyhedric containing a single large rounded basal or eccentric vesicular nucleus with prominent nucleolus. Extensive network of rough endoplasmic reticulum (RER) often arranged in an array parallel to the nuclear membrane with many mitochondria, and Golgi apparatus were described. The cytoplasm contained glycogen granules, vesicles or vacuoles scattered throughout the cytoplasm especially at the apical region were reported. The bile canaliculi and the hepatic "Kupffer" cells were also discussed. This is the first study on the histological characterization of the healthy liver of Yemen veiled chameleon in southern Saudi Arabia. The findings reported here should be used as a reference to compare with the pathological abnormalities of the liver in this animal.

está disponible en el texto completo

A morphological, histological and histochemical study of the sexual segment of the kidney of the male Chamaeleo calyptratus (veiled chameleon) / Un estudio morfológico, histológico e histoquímico del segmento sexual del riñón del macho Chamaeleo calyptratus (camaleón velado)

SUMMARY: This study aimed to describe the morphology, histology, and histochemistry of the kidneys and the sexual segment of the kidney (SSK) in Chamaeleo calyptratus (Yemen chameleons or veiled chameleons) collected during the active reproductive season. To achieve this objective, a total of 7 mature male Chamaeleo calyptratus were captured from their natural habitats from different areas in the Aseer region of Saudi Arabia and transferred to the reptilian laboratory where their kidneys were dissected out. Next, a morphological examination was conducted on the kidneys and the SSK was processed for light microscopic examinations with the primary focus placed on the morphology and histology of the SSK. The results of the study showed that Chamaeleo calyptratus possess two, reddish-brown, attenuated kidneys divided into lobes and lobules (lobulated). The histological study showed that the chameleons had no distinct limits between the cortex and medulla of the kidneys. In general, similar with other reptiles, this lizard demonstrated that the kidneys have few nephrons, do not show any nephron loop (loop of Henle), and display few glomeruli. The nephron is generally composed of standard components: renal corpuscle, glomerulus surrounded by a double-walled, the glomerular capsule (Bowman's capsule) and renal tubules (six renal tubular segments differentiated as the ciliated neck segment [between the glomerulus and the proximal segment], proximal segment, ciliated intermediate segment instead of nephron loop that connects proximal and distal, distal segment, terminal segment or sexual segment, and all segments emptying into the collecting ducts. The epithelial tissues lining the lumen of these segments vary from simple cuboidal cells to columnar and tall columnar cells in the SSK. Mature male Chamaeleo calyptratus possess hypertrophied parts of the distal renal segments, which are called the SSK. Histologically, the active SSK consists of simple tall columnar epithelial cells with rounded basal nuclei with clear centralized nucleoli and numerous apical coarse secretory granules which are released from the cells by an apocrine process. Histochemically, the secretory granules stain positively for proteins with mercuric bromophenol blue and react intensely to periodic acid-Schiff (PAS) for neutral carbohydrates. This is the first report about the histology of the SSK of the Chamaeleo calyptratus, and this study adds to the knowledge of the reproductive biology, biodiversity, and reproductive strategies of chameleons. Further studies are required to investigate the ultrastructure of the kidneys and SSK.

RESUMEN: Este estudio tuvo como objetivo describir la morfología, histología e histoquímica de los riñones y el segmento sexual en el riñón (SSK) del Chamaeleo calyptratus (camaleones de Yemen o camaleones con velo) recolectados durante la temporada reproductiva. Un total de 7 machos maduros de Chamaeleo calyptratus fueron capturados en su hábitat natural de diferentes áreas en la región de Aseer de Arabia Saudita y transferidos al laboratorio de reptiles donde fueron disecados los riñones. Posteriormente, se llevó a cabo un examen morfológico de los riñones y se procesó la SSK para exámenes con microscopio óptico con el enfoque principal puesto en la morfología y la histología. Los resultados del estudio mostraron que Chamaeleo calyptratus posee dos riñones atenuados de color marrón rojizo divididos en lóbulos (lobulados). En el estudio histológico se observó que los riñones de los camaleones no tenían límites definidos entre la corteza y la médula. En general, y similar a otros reptiles, este lagarto demostró que los riñones tienen pocas nefronas, no muestran ningún asa de Henle y presentan pocos glomérulos. La nefrona está compuesta por componentes estándar: corpúsculo renal (glomérulo rodeado por una pared de doble pared). Cápsula de Bowman y túbulos renales (seis segmentos tubulares renales diferenciados como el segmento del cuello ciliado [entre el glomérulo y el segmento proximal], segmento proximal, segmento intermedio ciliado en lugar del asa de Henle que conecta proximal y distal, segmento distal, segmento terminal o segmento sexual y todos los segmentos que desembocan en los conductos colectores Los tejidos epiteliales que recubren la luz de estos segmentos varían desde células cuboidales simples hasta células columnares y columnares altas en la SSK. Los machos maduros de Chamaeleo calyptratus poseen partes hipertrofiadas de los segmentos renales distales, denominados SSK. Histológicamente, la SSK activa consiste en células epiteliales cilíndricas altas simples con núcleos basales redondeados, nucléolos centralizados claros y gránulos secretores gruesos apicales que se liberan de las células por un proceso apocrino. Histoquímicamente, los gránulos secretores se tiñen positivamente para las proteínas con azul de bromofenol mercúrico y reaccionan intensamente al ácido periódico-Schiff (PAS) para obtener carbohidratos neutros. Este es el primer informe sobre la histología de la SSK de Chamaeleo calyptratus, y se suma al conocimiento de la biología reproductiva, la biodiversidad y las estrategias reproductivas de los camaleones. Se requieren más estudios para investigar la ultraestructura de los riñones y la SSK.

Imitadores y camaleones de ictus, para tenerlos siempre en mente / Stroke mimics and chameleons, have them always on mind

INTRODUCCIÓN: Se denominan imitadores de ictus (falsos positivos, sobrediagnosticados) así como camaleones de ictus (falsos negativos, infradiagnosticados) a los casos que inducen a cometer errores en el diagnóstico y tratamiento del ictus. Los mismos deben ser considerados para aproximarse de una manera certera al diagnóstico y tratamiento más adecuados. El objetivo es relatar el caso de una paciente que se presenta con un imitador de ictus, afortunadamente con evolución favorable posterior. CASO CLÍNICO: Paciente de 17 años, procedente y residente de la ciudad de El Alto, segundigesta, sin antecedentes personales patológicos, cuadro clínico de 8 horas de evolución, caracterizado por alteración de la conciencia de manera progresiva así como crisis convulsivas tónico clónicas generalizadas; se realiza neuroprotección, tratamiento neurointensivo y se considera tratamiento trombolítico, el cual debido a una adecuada disquisición diagnóstica se decide evitar, orientándose el diagnóstico hacia epilepsia, realizándose el tratamiento respectivo con evolución favorable. DISCUSIÓN: El caso presenta varios datos importantes, tales como la edad de la paciente y la ausencia de crisis convulsivas con anterioridad, sin embargo debido a la urgencia del caso se consideró trombolisis, sin administrase la misma y decidiéndose por el tratamiento de epilepsia, evitando tanto el riesgo asociado a hemorragia intracerebral por la administración de trombolítico en un caso que no correspondía su utilización ya que como se pudo evidenciar la literatura cita como un importante imitador de ictus a las crisis convulsivas.

INTRODUCTION: Stroke mimics (false positives, over diagnosed) and stroke chameleons (false negative, underdiagnosed) are special cases that induce to commit mistakes on stroke diagnoses and treatment. They have to be considered to approximate an adequate treatment. The objective is report the case of a patient with stroke mimic, fortunately identified and treated with favorable evolution. CASE REPORT: Female 17 year-old patient, from El Alto city, without pathologic antecedents with 8 hours clinical manifestations with consciousness impairment and tonic-clonic seizures, neuroprotection is performed such as neurocritical care, thrombolysis is considered, but after an adequate diagnostic disquisition is avoided, the diagnoses of epilepsy is achieved and treatment is performed. DISCUSSION: Several important data are reviewed, such as the early age, lack of seizures antecedent, nevertheless thrombolysis is considered, throughout a careful literature review, epilepsy treatment is performed, avoiding intracraneal bleeding complications.