Microvillus inclusion disease: a case report and literature review / 中华围产医学杂志

Objective:To investigate the clinical features and genetic mutations of microvillus inclusion disease (MVID).Methods:Clinical features and gene sequencing results of a neonate with MVID in Children's Hospital of Chongqing Medical University in August 2019 were retrospectively analyzed. Literature was retrieved up to October 2021, with the terms of microvillus inclusion disease, congenital microvilli atrophy, MVID, MYO5B, STX3, and STXBP2 in China National Knowledge Infrastructure, Wanfang Database, VIP database, and PubMed. Clinical features, diagnosis, and treatment of the reported MVID cases were reviewed. Results:(1) Case report: A male infant presented with jaundice two days after birth and was admitted to our hospital. Clinical features included intractable diarrhea, intermittent abdominal distension, uncorrectable dehydration, and weight loss. Laboratory test results indicated metabolic acidosis, electrolyte disorder, and cholestasis. Whole exome sequencing confirmed the diagnosis of MVID in this baby boy with compound heterozygous mutations of c.1021C>T(p.Q341*) and c.1125G>A(p.W375*) in the MYO5B gene, which were inherited from the father and the mother, respectively. (2) Literature review: Except for the present case, 31 patients from 20 articles were reviewed, and the typical clinical manifestations were intractable diarrhea, accompanied by dehydration, metabolic acidosis, electrolyte disorder, etc. Some patients also developed extra-gastrointestinal symptoms, including feeding difficulties and malnutrition (8/18), respiratory distress syndrome (4/18) and jaundice/cholestasis (4/18) in patients with MYO5B mutations; feeding difficulties and malnutrition (2/5), respiratory distress syndrome (1/5), and sepsis (1/5) in patients with STX3 mutations; feeding difficulties (2/9), respiratory distress syndrome (1/9), jaundice/cholestasis (1/9), sepsis (1/9), and hypoglycemia (1/9) in patients with STXBP2 mutations. In terms of the demographic data and prenatal examination, preterm birth (8/18), fetal bowel dilatation (5/18), polyhydramnios (5/18), parental consanguinity (2/18), and meconium-stained amniotic fluid (2/18) occurred among patients with MYO5B mutations. In those with STX3 mutations, parental consanguinity (3/5), fetal bowel dilatation (1/5), polyhydramnios (1/5), and meconium-stained amniotic fluid (1/5) occurred. Of nine patients with STXBP2 mutations, parental consanguinity (3/9), preterm birth (2/9), and polyhydramnios (2/9) occurred. Conclusions:MVID has atypical clinical features and a high mortality, resulting in difficulty in the diagnosis and treatment. The possibility of MVID should be considered when an infant presents with intractable diarrhea, dehydration, metabolic acidosis, and electrolyte disorder accompanied by multiple extra-gastrointestinal symptoms. Early identification of MYO5B, STX3, and STXBP2 mutations will benefit prompt intervention, prognosis evaluation, and genetic counseling.

Histomorphometry of preterm and term human placentas / Histomorfometría de placentas de pretérmino y término

The intra-uterine existence of foetus is dependent on placenta, a major organ of nutrition and homeostasis.The present study was carried out to compare morphometric and histological changes in preterm and term human placentas. Eighty placentas collected from Department of Obstetrics and Gynecology, JNMCH, AMU, Aligarh, were divided into group first of preterm placentas up to 36 weeks (n =30) and second group of full term placentas i.e. 37 to 40 weeks ( n = 50) respectively. The samples were fixed in 10 percent formol-saline solution. The gross morphological variables of placentas were studied. There was a significant increase in the placental weight, decidual area and umbilical cord diameter of term placenta as compared to that of the preterm ones. From each placenta whole thickness tissue blocks were taken and processed for paraffin sectioning. Five µ-thick sections were stained with Haematoxylin-eosin and Van Gieson stains and processed for light microscopy. A total of 200 villi were studied in each sample under high power field and occurrence of different features was expressed as percentages for each parameter. The appearance of microvilli and syncytial bud on the syncytium were almost absent in the villi of term placentas. It was concluded that with increasing gestational age there was a gradual increase in the number of capillaries in villi from preterm to term placenta.There was a significant increase in syncytial knot count, fibrinoid necrosis, vasculosyncytial membrane and decrease in the percentage of villi showing cytotrophoblastic cells and number of Hofbauer cells in term group as compared to preterm group.

La existencia intrauterina del feto depende de la placenta, el mayor órgano de nutrición y homeostasis. El estudio se llevó a cabo para comparar los cambios morfométricos e histológicos de la placenta humana de término y pretérmino. Ochenta placentas fueron obtenidas del Departamento de Obstetricia y Ginecología, JNMCH, AMU, Aligarh y se dividieron en grupos, el primer grupo de placentas de pretérmino hasta 36 semanas (n = 30) y el segundo grupo de placentas de término, de 37 a 40 semanas (n = 50 ). Las muestras fueron fijadas en solución de formol-salina al 10 por ciento. Se estudiaron las variables morfológicas macroscópicas de las placentas. Hubo un aumento significativo en el peso de la placenta, el área de decidua y el diámetro del cordón umbilical de la placenta a término en comparación con la de los prematuros. De cada placenta se tomaron y se procesaron bloques de tejido para incluirlos en parafina. Cortes de 5 µm fueron teñidos con HE y Van Gieson para microscopía óptica. De cada muestra fueron estudiadas 200 vellosidades, bajo campo de alta resolución y la aparición de diferentes características se expresó como porcentajes para cada parámetro. La aparición de las microvellosidades y brote sincitial en el sincitio estaban casi ausente en las vellosidades de las placentas de término. Se puede concluir que al aumentar la edad gestacional hubo un aumento gradual en el número de capilares en las vellosidades de la placenta de término. Existe un aumento significativo en el recuento de nudo sincitial, necrosis fibrinoide, membrana vasculosincisial y disminución en el porcentaje de las vellosidades que muestran células citotrofoblástica y número de células de Hofbauer en las placentas del término de grupo en comparación con el grupo de pretérmino.

Fatty acid composition of Drosophila photoreceptor light-sensitive microvilli

Phototransduction, the mechanism underlying the electrical response to light in photoreceptor cells, has been thoroughly investigated in Drosophila melanogaster, an essential model in signal transduction research. These cells present a highly specialized photosensitive membrane consisting of thousands of microvilli forming a prominent structure termed a rhabdomere. These microvilli encompass the phototransduction proteins, most of which are transmembrane and exclusively rhabdomeric. Rhabdomere membrane lipids play a crucial role in the activation of the transient receptor potential ionic channels (TRP and TRPL) responsible for initiating the photoresponse. Despite its importance, rhabdomere lipid composition has not been established. We developed a novel preparation enriched in rhabdomere membranes to perform a thorough characterization of the lipidomics of Drosophila rhabdomeres. Isolated eyes (500) were homogenized and subjected to a differential centrifugation protocol that generates a fraction enriched in rhabdomere membrane. Lipids extracted from this preparation were identified and quantified by gas chromatography coupled to mass spectrometry. We found an abundance of low sterol esters (C16:0, C18:0), highly abundant and diverse triglycerides, free fatty acids, a moderate variety of mono and diacyglycerols (C:16:0, 18:0, C18:1) and abundant phospholipids (principally C18:2). This preparation opens a new avenue for investigating essential aspects of phototransduction.

Observaciones al microscopio electrónico de barrido del interior de un proglótido de un parásito adulto de taenia solium / Scanning electron microscopy observations of the cross-section of a taenia solium adult tapeworm

No existen, hasta el momento, imágenes que muestren la disposición de la citoarquitectura de parásitos adultos de Taenia solium, parásitos los cuales se encuentran en el intestino de portadores humanos asintomáticos. Las causas de ello podrían tener como base el que cuando se recuperan los parásitos, ellos han sufrido alteraciones debidas a la respuesta inmune de sus hospederos o bien, por el efecto que han producido en los parásitos los fármacos antihelmínticos que hayan sido usados en el tratamiento de los pacientes. Una de las alternativas que se han encontrado para la obtención de parásitos adultos, es la obtención de tenias a partir del modelo de teniosis experimental en hámsteres dorados e inmunosuprimidos y que gracias a este modelo se han podido efectuar diferentes tipos de estudios de los parásitos de esta fase infectiva. El propósito de este reporte es presentar imágenes de ultraestructura, obtenidas mediante Microscopía Electrónica de Barrido, de un corte transversal obtenido de un proglótido de una tenia recuperada de una infección experimental. Las imágenes se obtuvieron a diferentes aumentos y muestran aspectos relacionados con la superficie tegumentaria, el tegumento sincicial continuo, la capa germinal que incluye el soma de algunas células subtegumentarias y los ductos del sistema protonefridial tanto vacíos como llenos con corpúsculos calcáreos. Las imágenes ultraestructurales obtenidas muestran una forma de observación de la anatomía microscopica de los parásitos en estudio y ello contribuye a ampliar el conocimiento de los mismos en relación a aspectos de su biología celular y su fisiología.

There are no clear morphological evidences of the cytoarchitecture of intestinal adult tapeworms of Taenia solium recovered from infected humans. Parasites could be altered because of the host´s immunological response or by the direct action of drugs used for antihelminthic treatment. Experimental taeniosis in immunosuppressed golden hamsters is a useful way for recovering and studying adult parasites. The purpose of this report is to show images, taken at the ultrastructural level by Scanning Electron Microscopy (SEM), of a cross-sectioned strobilar chain from an adult tapeworm. The parasite was recovered from an experimental infection. Images were taken at several magnifications; they show the brush border tegumental surface, the syncytial tegument, the germinal layer, some cell bodies and the protonephridial system ducts: empty or filled with calcareous corpuscles. Ultrastructural images taken using SEM of T. solium adult parasites, recovered from experimental infections, could be a new way for observing the microscopic anatomy of these parasites and for increasing the knowledge of aspects related to their cellular biology and physiology.

Protracted Diarrhea: Results of the Five-year Survey in a Tertiary Hospital in Korea

The syndrome of protracted diarrhea (PD) includes several diseases with diverse etiologies. This study was conducted to characterize the spectrum of causes, clinical manifestations, and the outcomes of PD. A retrospective analysis of the clinical and pathological findings was performed on 25 patients with diarrhea starting within the first 2 yr of life and a requirement of parenteral nutrition (PN). According to the intestinal histopathology, patients were classified into four groups: immune enteropathy (12 cases), lymphangiectasia (6 cases), epithelial dysplasia (5 cases), and unclassified (2 cases). All patients with epithelial dysplasia had earlier onset of diarrhea and longer duration of PN than those in the other groups. Three patients (12%) had an evidence of a familial condition. Five patients (three with microvillous inclusion disease and two with immune enteropathy) died. Sixteen patients recovered, and three (two with primary lymphangiectasia and one with microvillous inclusion disease) still had diarrhea. One patient underwent intestinal transplantation for tufting enteropathy. In conclusion, infants with PD should be referred to specialized centers where advanced diagnostic and therapeutic facilities are available, because histological analysis is critical for the diagnosis of PD, and PN or intestinal transplantation is the only therapeutic option in a subset of cases.

The Effects of Cytochalasin B and Colchicine on Fine Structure of Bile Canaliculi and Hepatocytes in Mouse Liver / 대한해부학회지

Bile canaliculi is closely related to the cytoskeleton; actin filament web, microtubules and cytokeratin intermediate filaments. To understand how cytoskeletal alteration affects bile canalicular structure, the investigators injected cytochalasin B and colchicine into mice intraperitoneally to inhibit the polymerization of actin filaments and microtubules respectively, and observed the structural changes of bile canaliculi and hepatocytes with transmission and scanning electron microscopes. Bile canaliculi were dilatated and microvilli were decreased in number and length after injection of cytochalasin B and colchicine. Some bile canaliculi branched irregularly after colchicine treatment. Actin filament web in the canalicular ectoplasm was disrupted leaving granular zone after cytochalasin B treatment, but was intact after colchicine treatment. Intermediate filament bundles located at angles to the canalicular membrane appeared after colchicine treatment. Intercellular junctions delimiting bile canaliculi were intact after colchicine treatment, however were disrupted after cytochalsin B treatment. Focal junctions resembling desmosome were formed between microvilli after colchicine treatment. In both cytochalasin B and colchicine treated groups, lumen of rough endoplasmic reticulum were dilated, Golgi apparatus became prominent, and lipid droplets were appeared in the cytoplasm. These results suggest that both intact actin filaments and microtubules are necessary to keep the structural integrity of bile canaliculi.

Fine structure of olfactory epithelium in Schizothoraichthys progastus McClelland and Schizothorax richardsonii Gray (Cyprinidae: Teleostei) from Garhwal Himalaya (India).

The olfactory epithelium of two closely related species of snowtrout— Schizothoraichthys progastus McClelland and Schizothorax richardsonii Gray (Subfamily: Schizothoracinae. family-Cyprinidae, Teleostei), from a perennial glacier-fed river Mandakini of Garhwal hills was studied by employing transmission electron microscopic method The olfactory lamella comprises two epithelia—anterior and posterior, with a stroma sandwiched in between. Both are strartified. The anterior one is thicker than posterior. In Schizothoraichithys progastus, the sensory part of epithelium has two types of receptor cells—ciliated receptor cells and rod cells whilst in Schizothorax richardsonii, there arc three types of receptor cells—ciliated receptor cells, microvillous receptor cells and rod cells in addition to sustentacular cells, basal cells and mucous cells. While inhabiting similar hillstream habitat, the differential ecological niches, feeding habits etc., account for the presence of different receptor cell types in these species, It implies the possible diversification at cellular and physiological levels so as to minimize the competition by using varied olfactory cues.

Peritoneal Diffuse Anaplastic Malignant Mesothelioma Simulating Anaplastic Carcinoma

A case of diffuse malignant mesothelioma of peritoneum which was difficult to distinguish from metastatic anaplastic carcinoma or malignant melanoma was presented. The patient was a 50 year-old woman and complained of an abdominal pain and ascites for 20 days. Histologically, the tumor cells showed highly anaplastic appearance with sheet-like arrangement without any papillary or tubular structure. They stained Positive for cytokeratin and vimentin and negative for CEA, S-100 protein and melanoma associated antigen. A few cells within the tumor showed Positive reactivity to desmin. Ultrastructurally, the tumor cells had characteristic findings of mesothelioma such as long, exuberant, wavy microvilli with 10 to 12 of length/diameter ratio. The patient died 3 months after the diagnosis in spite of intraperitoneal chemotherapy.

Electron Microscopic Studies on Invasion of Malignant Cells to Smooth Muscle Cells / 昆明医科大学学报

The invasion of malignant cells into smooth muscle cells was shown by EM.We dicsovered that the malignant cells adhered to and penetrated the smooth muscle cells with their microvilli and pseudopodia.The microfilament in the microvilli and pseudopodia is the motion skeleton of cancer cells.Studying the structure and function of the microfilament fur- ther is important for researching the metastasis of tumor.

Structure and Function of Microvilli of Malignant Cells / 昆明医科大学学报

After studying the surface structure of 9 kinds of malignant cells cultured on the three-dimensional substratum by SEM and TEM,it was found that myriad microvilli appeared on the surface of the malignant cells.The number and distribution varied with the cell cycle.The function of the microvilli was related with the nutrition,migration and invasion of the malignant cells.The microfilament is the skeletal structure of microvilli.

COMPARATIVE STUDY ON THE STRUCTURAL CHARACTERISTICS OF MICROFILAMENTS IN CELLS WITH DIFFERENT METASTATIC ABILITY CLONED FROM HUMAN GASTRIC CANCER CELL LINE BGC-823 / 解剖学报

Ten cell strains were obtained from the human gastric cancer cell line BGC-823 by using the method of single cell cloning. Through inoculation of these cell strains in nude mice and subsequent observation of their metastatic capability, four cell lines, C_1, C_6 with high, and C_5, C_8 with low metastatic capability were selected out; and their biological and morphological properties were studied. It was demonstrated that all of them did not show apparent difference in growth ability, but morphologically, the mictovilli of C_5 and C_8 cells were scarce and short; and their microfilaments were thick, straight and well organized. Whereas the microvilli of C_1 and C_6 strains were long and abundant comparatively, but their microfilaments were poorly organized. On the basis of present observation,we suggested that the organization of microfilaments in cancer cells appeared to bear reversed relationship with their metastatic capability.

ELECTRON MICROSCOPIC OBSERVATION OF THE CYTOCHEMICAL CHANGES OF Mg~(++), (Na~+-K~+)- ATPase, cAMP-PDE OF THE EFFECT OF 3', 5'- cAMP ON HEPATOMA-22 ASCITIC TUMOR CELLS IN VIVO / 解剖学报

The experiment was carried out on Hepatoma-22 ascitic tumor cells of mice in vivo. Daily injection of 2 mg cAMP with 1 mg theophylline into the peritoneal cavity for 7 and 8 days, then these animals were sacrificed. We found that cAMP with theophylline inhibit the growth of tumor cells of Hepatoma-22 ascitic and decrease the activity of Mg~(++), (Na~+-K~+)-ATPase and cAMP-PDE on the cell surface of H-22 tumor cells of mice by cytochemical electron microscopy. Exogenic cAMP and theophlline decrease the activities of these enzymes and elevate the intracellular content of cAMP. These may indicate the reversion transformation of the cancer cell.

THE EFFECT OF dbcAMP ON THE MURINE U_(14) ASCITIC TUMOR CELLS SCANNING ELECTRON MICROSCOPIC OBSERVATION AND FLOW MICROCYTOMETRIC ANALYSIS / 解剖学报

dbcAMP was injected i. p. into four U_(14) ascitic tumor bearing mice on 3,4,5,6 and 7 days after inoculation of tumor cells. The ascites was aspirated 0.5-1 hour after last injection. For scanning electron microscopy, the tumor cells, washed twice in Hanks solution, were fixed in glutaraldehyde and OsO_4, dehydrated with ethyl alcohol and dried with camphene. For flow microcytometric analysis, the treated tumor cells were fixed in 70% cold ethyl alcohol and stained with propidium iodide. Under SEM, the untreated tumor cells were large, spherical, and uniform in size with numerous long thin microvilli on the cell surface. A few barely visible minute protrusions were present on the microvilli and cell membrane. The great majority of treated tumor cells became smaller and variable in size, with shortened microvilli which reduced in number and even disappeared in some area. Many granular protrusions, larger than that of the control, were clearly observed on the cell membrane and microvilli. The result of flow microcytometric analysis showed that the DNA histogram and cell cycle profile from dbcAMP treated cells have no significant difference from the untreated controls, so it is evident that morphologic changes resulted from dbcAMP were not caused by cell cycle alteration. The morphogenesis of microvilli and cell membrane changes in dbcAMP treated cells is not clear. The relation of these configurations to differentiation of malignant tumor cells is discussed.

SEM STUDY ON THE MUCOSA OF DIGESTIVE TRACT OF OPHICEPHALUS ARGUS CANTOR / 解剖学报

The mucosal surface of the digestive tract of Ophicephalus argus Cantor was observed with scanning electron microscope. The ultrastructural features of buccopharynx, oesophagus, stomach and intestine were observed. There are many microridges on the surface of mucosal cells of the buccopharynx and oesophagus. On the surface of mucosal cells of the stomach and intestine exist many microvilli, and numerous goblet cells located in the mucosal epithelium of the buccopharynx, oesophagus and intestine. These structural features may be related to feeding habits of Ophicephalus; argus.