Related factors of intestinal necrosis caused by midgut volvulus in neonates / 中国新生儿科杂志

Objective:To study the characteristics and related factors of neonatal intestinal necrosis caused by midgut volvulus.Methods:We retrospectively analyzed the clinical data of neonates with midgut volvulus who were admitted to Guangzhou Women and Children's Medical Center, from January 2009 to December 2019 and confirmed by surgery. The cases with intestinal necrosis belong to the intestinal necrosis group, and those without intestinal necrosis, the non-intestinal necrosis group which was randomly sampled at a ratio of about 4∶1 to the number of cases in the intestinal necrosis group. The two groups were compared in terms of personal history, age of onset, initial symptoms, vital signs within 2 h after admission, time from symptom onset to operation, clinical outcome, laboratory indicators within 2 h after admission, etc. Multivariate Logistic regression analysis was used to screen the related factors of intestinal necrosis in midgut volvulus. The effective warning indexes are screened by receiver operating characteristic (ROC) curve.Results:(1) Among 231 cases of midgut volvulus, 21 cases (9.1%, 21/231) had intestinal necrosis at the time of operation, 87 cases were included in the non-intestinal necrosis group. (2) The levels of heart rate within 2 h after admission, mean arterial pressure, WBC, C reactive protein (CRP), blood glucose and potassium in intestinal necrosis group were significantly higher than those in non-intestinal necrosis group ( P<0.05). Admission days of age, hemoglobin, serum albumin, serum sodium, pH and BE levels were significantly lower than those in the group without intestinal necrosis ( P<0.05). (3) In the multivariate analysis, increased heart rate, mean arterial pressure, serum CRP, and decreased serum sodium, serum albumin, and pH levels were predictors related to intestinal necrosis in patients with midgut volvulus. (4) The area under the ROC curve (AUC) of CRP was 0.883, the cutoff value was 9.88 mg/L, the sensitivity was 76.2%, and the specificity was 94.3%. The ROC curve of serum albumin was 0.792, the cut-off value was 36.65 g/L, the sensitivity was 70.1%, and the specificity was 94.3%. Conclusions:Heart rate, mean arterial pressure, increased CRP, decreased serum sodium, serum albumin and pH are helpful to predict whether intestinal necrosis occurs in midgut volvulus, and CRP > 9.88 mg/L and serum albumin < 36.65 g/L are likely warning indicators.

Vólvulo de intestino medio: a propósito de dos casos / Middle intestine volvulus: on the purpose of two cases / Volvulus do intestino médio: com propósito de dois casos

La malrotación intestinal es un espectro de malformaciones, que incluye una gran variedad de alteraciones en el proceso de rotación y fijación del intestino. La ausencia completa de rotación intestinal, uno de los tipos de malrotación intestinal más frecuentes, puede presentarse como hallazgo asintomático o manifestarse clínicamente por un vólvulo del intestino medio. Sin embargo, incluso entre aquellos que se presentan con vólvulo del intestino medio, la clínica puede ser muy diferente, según el grado de isquemia y eventual necrosis intestinal. Se presentan dos casos clínicos de malrotación intestinal con vólvulo del intestino medio con presentaciones, imágenes, tratamientos y evoluciones muy disímiles. Se analizan los mismos a la luz de una revisión bibliográfica relevante al tema tratado, se sacan aprendizajes del manejo realizado y la evolución que presentaron, y se enfatizan los elementos de mayor jerarquía para optimizar el manejo de estos pacientes.

Intestinal malrotation is a spectrum of malformations that includes a great variety of alterations in the rotation and fixation process of the intestines. The total absence of intestinal rotation, one of the most frequents types of intestinal malrotation could present as an asymptomatic find or appear clinically as a midgut volvulus. However, even those that appear as midgut volvulus, could show quite different signs and symptoms according to the degree of ischemic insult and possible intestinal necrosis. Two clinical cases of intestinal malrotation with midgut volvulus with quite different presentations, images, treatments, and evolutions, are informed. The two cases are analyzed under a relevant bibliographic revision, knowledge is derived from the carried-out management and evolution, and elements for the future optimization of management are underlined.

A má rotação intestinal é um espectro de malformações, que inclui uma grande variedade de alterações no processo de rotação e fixação do intestino. A ausência completa de rotação intestinal, um dos tipos mais comuns de má rotação intestinal, pode se apresentar como um achado assintomático ou manifestar-se clinicamente como um volvo de intestino médio. Porém, mesmo entre aqueles que apresentam volvo de intestino médio, os sintomas podem ser muito diferentes, dependendo do grau de isquemia e eventual necrose intestinal. Dois casos clínicos de má rotação intestinal com volvo de intestino médio são apresentados com apresentações, imagens, tratamentos e evoluções muito diferentes. São analisados ​​à luz de uma revisão bibliográfica pertinente ao tema em questão, lições aprendidas com o manejo realizado e a evolução que apresentaram, e os elementos de maior hierarquia são enfatizados para otimizar o manejo desses pacientes.

Ex Vivo Effect of Ibogaine on the Transcriptional Level of Antioxidant Defense Related Genes in Honey Bee (Apis mellifera, L.) Midgut

Abstract The aim of the present study was to analyze the mechanisms of ibogaine action by measuring its ex vivo effects on antioxidant defense in the honey bee (Apis mellifera, L.) midgut. The transcriptional levels of selected genes: Cu/Zn dependent and Mn dependent superoxide dismutases (Sod1 and Sod2, respectively), catalase (Cat) and transcription factor Nrf2 (Nrf2) were determined. The applicability of midgut tissue, which expected to have well developed antioxidant protection system, for this type of analysis was confirmed by testing cell viability and response to paraquat, an effective inducer of oxidative stress, ex vivo. Incubation for 2 h with paraquat (10 µg/mL) induced a significant increase in expression of Sod1 and Cat genes. The results of ibogaine treatment showed that exposure to 5 µg/mL and 10 µg/mL of ibogaine for 2 h induced significant increase in expression of Sod1 gene. On the other hand, ibogaine did not lead to a significant increase of Sod2, Cat and transcription factor Nrf2 genes expression in honey bee midgut ex vivo. Our results confirmed positive effect of ibogaine on the antioxidant protective system and its pro-antioxidant action.

A rare presentation of midgut malrotation as an acute intestinal obstruction and perforation in an adult

Midgut malrotation is a congenital anomaly seen usually in childhood. Its presentation as an acute intestinal obstruction is extremely rare in adults usually identified intra operatively. A high index of suspicion is always required when dealing with any case of acute intestinal obstruction. We report a case of young adult who presented with symptoms of acute intestinal obstruction and was diagnosed intra-operatively as cecal volvulus with impending perforation caused by midgut malrotation. Malrotation of the intestinal tract is seen due to aberrant embryology. The presentation of intestinal malrotation in adults is very rare. Contrast enhanced Computed tomography (CT) can show the abnormal anatomy clearly. Anomalies like midgut malrotation can present as an operative dilemma and awareness regarding these conditions can help surgeons deal with these conditions.

A rare acute presentation of intestinal malrotation in the elderly

Intestinal malrotation, a congenital anomaly of the midgut, typically presents in pediatrics age group with the most feared complication of midgut volvulus and its catastrophic sequelae. Midgut volvulus secondary to intestinal malrotation is a rare presentation in adults more so in the elderly. Its rarity portends a diagnostic dilemma for both the surgeon and radiologist. We report a 65-year-old man admitted following a referral with a 12-hour history of acute abdomen with an initial diagnosis of acute pancreatitis but later had laparotomy with intraoperative findings of a midgut volvulus and gangrenous ileal segment secondary to intestinal malrotation. This case emphasizes the importance of early diagnosis to prevent the disastrous complication of this disease. The rarity of this condition portends a formidable diagnostic challenge in adults hence the awareness of its possibility and a high index of suspicion is crucial in diagnosis.

Midgut cells alteration in gamma-irradiated beetles (Blaps polycresta, Coleoptera: Tenebrionidae) / Alteração das células do intestino médio em besouros irradiados com radiação gama (Blaps polycresta, Coleoptera: Tenebrionidae)

Abstract This study was conducted to examine the effect of gamma radiation on biological specimens. Thus, our concept is to clarify that exposure to accumulated dose of 0.2 Gy gamma rays (0.66 rad/Sec. dose rate) from Cs137 source induces cellular perturbations in the midgut epithelium of the F1 progeny of Blaps polycresta, therefore affecting nutrition and growth. Beetles were reared in laboratory conditions and the newly emerged adults were irradiated with the aforementioned dose. Histological and ultrastructure anomalies of midgut cells (digestive and regenerative cells) were observed by 72 h after radiation exposure to ensure that the cells will not return to control state. Retardation in the development of the F1 progeny was also noticed and beetles died through two weeks. In the light of these observations, biological tissue act as an indicator to the continuous exposure to environmental radiation.

Resumo Este estudo foi conduzido para examinar o efeito da radiação gama em espécimes biológicos. Assim, nosso conceito é esclarecer que a exposição à dose acumulada de raios gama de 0,2 Gy (0,66 rad / seg. Dose) da fonte Cs137 induz perturbações celulares no epitélio do intestino médio da progênie F1 de Polycresta blaps, afetando a nutrição e crescimento. Besouros foram criados em condições de laboratório, e os adultos recém-emergidos foram irradiados com a dose acima mencionada. Anomalias histológicas e ultraestruturais das células do intestino médio (células digestivas e regenerativas) foram observadas 72 horas após a exposição à radiação, para garantir que as células não retornariam ao estado de controle. Retardo no desenvolvimento da progênie F1 também foi notado, e besouros morreram por duas semanas. À luz dessas observações, os tecidos biológicos atuam como um indicador para a exposição contínua à radiação ambiental.

Structure of the mouthparts and alimentary canal of Eusomus ovulum Germar, 1824 (Coleoptera: Curculionidae)

ABSTRACT The structural morphology of mouthparts, the distribution of sensilla on the mouthparts, histology, and the morphology of the alimentary canal in adult Eusomus ovulum Germar, 1824 were examined under both light and scanning electron microscopy (SEM). The mouthparts are located at the tip of the short rostrum. The mandibles, the maxillae and the labial palpi comprise the moveable mouthparts. Also there are sensillae which act as chemoreceptors on the terminal segment of the snout. Alimentary canal of adult E. ovulum is divided into three main regions, foregut, midgut and hindgut. The first part of the gut is foregut, which is made up of a pharynx, esophagus, crop and proventriculus. The pharynx extends from the mouth, having muscle attachments radiating out from its surface and connecting with the head region. The esophagus is a narrow epithelial tube contiguous and posterior to the pharynx. The proventriculus consists of 8 sclerotized plates. The midgut, which is anteriorly bulbous with a tubular posterior half. Gastric caeca were found on the posterior region of the midgut. The midgut is surrounded by outer muscles and inner columnar epithelium. The hindgut has pylorus, ileum, colon, and rectum. There are three histological layers of the hindgut from lumen to hemocoel: intima, epithelium, muscles. The hindgut has a cryptonephridial attachment for the six Malpighian tubes anterior to the rectum. The aim of the present study is to contribute information on the morphology of mouthparts, and the morphology and histology of the alimentary tract of the insect.

Adult intestinal malrotation: a case report

Midgut malrotation is an incomplete rotation of the intestine which occurs during foetal development and usually presents in the neonatal period. The bowel is not fixed adequately and is thus held by a precariously narrow-based mesentery. The incidence of malrotation has been estimated at 1 in 6000 live births, it is rare for malrotation to present in adulthood. Author report a 40-year-old man presented to emergency department with generalized abdominal pain. His symptoms began 2 days before admission. The patient really weak and his mental state was somnolence. His abdomen was slightly extended, and intestinal peristalsis was obscure. Abdominal X-rays revealed dilatation of gastric, coiled spring appearance without free air and step ladder pattern. The patient then underwent laparotomy exploration. Upon entering the abdomen, ileum was noted to completely mobilized and founded volvulus segment, a clockwise twisting three times, about 30 cm proximal from ICJ, and soon author released it. The ligament of Treitz misplaced, there was in the right lower quadrant, close by ICJ. Then about 110 cm segment of ileum necrotic, the rest of the small bowel was normal, author found internal hernia in the right lower quadrant and there was Ladd's band. Clinicians should be aware of this serious cause of abdominal pain. The diagnosis of malrotation in adulthood is often delayed. Complete resolution of acute obstruction or chronic abdominal pain is the result of a high index of suspicion for malrotation, appropriate diagnostic studies, and aggressive treatment.

Waardenburg Syndrome Type IV De Novo SOX10 Variant Causing Chronic Intestinal Pseudo-Obstruction / 대한소아소화기영양학회지

Waardenburg syndrome (WS) type IV is characterized by pigmentary abnormalities, deafness and Hirschsprung's disease. This syndrome can be triggered by dysregulation of the SOX10 gene, which belongs to the SOX (SRY-related high-mobility group-box) family of genes. We discuss the first known case of a SOX10 frameshift mutation variant defined as c.895delC causing WS type IV without Hirschsprung's disease. This female patient of unrelated Kuwaiti parents, who tested negative for cystic fibrosis and Hirschsprung's disease, was born with meconium ileus and malrotation and had multiple surgical complications likely due to chronic intestinal pseudo-obstruction. These complications included small intestinal necrosis requiring resection, development of a spontaneous fistula between the duodenum and jejunum after being left in discontinuity, and short gut syndrome. This case and previously reported cases demonstrate that SOX10 gene sequencing is a consideration in WS patients without aganglionosis but with intestinal dysfunction.

Anatomical Variations In The Branching Pattern Of Superior Mesenteric Artery In Adult Human Cadavers

Background: In the medical field, the trend of the surgical branches has moved towards minimal invasivesurgeries for reasons of decreased morbidity and mortality. To achieve this is thorough knowledge of the anatomy,with the variations of the concerned structure is required. Hence for a structure like superior mesenteric artery,the anatomic variations of its origin and branching pattern is important for accurate interpretation in diagnosticimaging, as well as in deciding the optimum elective procedure in surgical radiological, and interventionalmanagement.Materials and methods: The study was carried out in 50 well embalmed cadavers of South Indian origin irrespectiveof age and sex. Variations in the branches of superior mesenteric artery were noted.Results: Inferior pancreaticoduodenal artery arose from the first jejunal artery. Middle colic and right colicarteries arose as common trunk. The right colic artery was absent. Ileocolic artery arose as common trunk withright colic artery.Conclusion: A thorough knowledge of the anatomy of colonic mesenteric arteries is necessary to accomplishsuccessful uncomplicated abdominal operations, especially laparoscopic colonic resection for cancer usingproximal vascular ligation and wide-en-block resection in which the mesenteric vessels cannot be palpated.

Histological and Histochemical Characterization of the Midgut of Healthy Aedes aegypti Larvae

Aedes aegypti (Diptera, Culicidae) is the predominant mosquito vector of several arboviruses such as dengue fever, yellow fever, chikungunya and zika. The larval stage is the major period of feeding and growth of these insects. Many of the products tested for Ae. aegypti control are ingested by the larvae in their natural environment or under laboratory conditions. In some situations, the identification of tissue lesions caused by the ingestion of such products serves as the primary way to understand their mechanism of action and confirm their effectiveness. Therefore, we aimed to conduct studies on the histological and histochemical characteristics of Ae. aegypti larvae in order to contribute to a better understanding of the pathogenicity caused by chemical or biological products for larval control. Therefore, we characterized tissues in the midgut of healthy Ae. aegypti larvae and present high quality images. These images are intended for comparison with results of morphohistochemical studies testing the effect of control substances in mosquito larvae.

Midgut cells alteration in gamma-irradiated beetles (Blaps polycresta, Coleoptera: Tenebrionidae)

Abstract This study was conducted to examine the effect of gamma radiation on biological specimens. Thus, our concept is to clarify that exposure to accumulated dose of 0.2 Gy gamma rays (0.66 rad/Sec. dose rate) from Cs137 source induces cellular perturbations in the midgut epithelium of the F1 progeny of Blaps polycresta, therefore affecting nutrition and growth. Beetles were reared in laboratory conditions and the newly emerged adults were irradiated with the aforementioned dose. Histological and ultrastructure anomalies of midgut cells (digestive and regenerative cells) were observed by 72 h after radiation exposure to ensure that the cells will not return to control state. Retardation in the development of the F1 progeny was also noticed and beetles died through two weeks. In the light of these observations, biological tissue act as an indicator to the continuous exposure to environmental radiation.

Resumo Este estudo foi conduzido para examinar o efeito da radiação gama em espécimes biológicos. Assim, nosso conceito é esclarecer que a exposição à dose acumulada de raios gama de 0,2 Gy (0,66 rad / seg. Dose) da fonte Cs137 induz perturbações celulares no epitélio do intestino médio da progênie F1 de Polycresta blaps, afetando a nutrição e crescimento. Besouros foram criados em condições de laboratório, e os adultos recém-emergidos foram irradiados com a dose acima mencionada. Anomalias histológicas e ultraestruturais das células do intestino médio (células digestivas e regenerativas) foram observadas 72 horas após a exposição à radiação, para garantir que as células não retornariam ao estado de controle. Retardo no desenvolvimento da progênie F1 também foi notado, e besouros morreram por duas semanas. À luz dessas observações, os tecidos biológicos atuam como um indicador para a exposição contínua à radiação ambiental.

Diagnostic function of ultrasonography in malrotation of intestine with midgut volvulus / 中国小儿急救医学

Objective Malrotation of intestine with midgut volvulus is a special disease in newbo-rns.It is important of early diagnosis to avoid the risk of intestinal infarct and necrosis.We intended to ex-plore the value of early ultrasonographic diagnosis in malrotation of intestine with midgut volvulus,comparing with upper gastrointestinal imaging.Methods Ultrasonographic features and upper gastrointestinal imaging of 48surgically confirmed malrotation of intestine with midgut volvulus between January 2011and December 2014were retrospectively analyzed.Results All patients were comfirmed by operaion.The rotational degree of midgut volvulus were 90to 720°.In 43of 48patients (89.58%)of malrotation of intestine with midgut volvulus were diagnosed by ultrasonography.The typical ultrasonographic features were called “whirlpool sign”,which was the superior mesenteric vein and the mesentery around the superior mesenteric artery.In 35 of 48(72.92%)patients with malrotation were confirmed by the upper gastrointestinal imaging.The typical sign of the upper gastrointestinal imaging was the helical form of the distal duodenum and proximal jejunum located at middle abdomen.Compared with upper gastrointestinal radiographic examination,ultrasonographic examination had more sensitivity in diagnosis of malrotation of intestine with midgut volvulus (P﹤0.05). Conclusion Ultrasonographic examination have more sensitivity in diagnosis.Noninvasiveness,absence of X-rays,and low costs could make ultrasonographic examination a useful screening test in patients with sus-pected malrotation of intestine with midgut volvulus.“Whirlpool sign”could be considered a specific ultra-sonographic sign in diagnosis of midgut volvulus,which could provide reference for the clinical treatment of malrotation of intestine with midgut volvulus.

Biological activity of Dolichos biflorus L. trypsin inhibitor against lepidopteran insect pests.

Protease inhibitors confer resistance in plants against insect pests by inhibiting larval gut proteases. Cultivars of Dolichos biflorus were screened for their inhibitory activity against midgut proteases of Pieris brassicae larvae. Seed extracts of developing and germinating seeds of HPK4 cultivar inhibited larval gut proteases of Spodoptera littoralis efficiently. Neonate larvae of P. brassicae fed on cabbage leaf discs coated with 0.025-2.50 mg protein (seed extract) resulted in 10-80% larval mortality and significantly reduced leaf area eaten and faecal matter as compared to control. The treated larvae had 40% less soluble proteins per mg faecal matter and there was similar decline in midgut proteases of treated larvae (@ 2.5 mg protein) compared to untreated ones after 5 days. The LC50 and LT50 value was calculated to be 1.05 mg/leaf disc and 4.8 days (2.5 mg protein), respectively for neonate larvae of P. brassicae. Significant reduction in egg hatching (75%) was observed in egg mass treated with 5.3 mg of crude inhibitor protein of mature seeds. This could be due to the inhibition of proteases involved in the hydrolysis of egg chorion proteins. The studies demonstrated the insecticidal activity of D. biflorus seed extracts.

Ultra Structure of the Mid-Gut of the Third Instar Larvae of Sarcophaga Aegyptiaca (Diptera: Sarcophagidae).

The mid-gut of third instar larvae of Sarcophag aegyptiaca was divided into anterior, middle and posterior mid-gut regions. A well-developed peritrophic membrane appeared in the apical part of the anterior and middle portions of mid-gut while it is absent from the posterior portion. The microvilli differs in 3 portions, appeared as apical membrane in the anterior portion, sparse in middle portion to long slender compact microvilli in posterior portion. Numerous organelles were observed throughout the cytoplasm of the 3 portions; lipid spheres, rough endoplasmic reticulum, seceretory vesicles and mitochondria. A large apically nucleus appeared in the 3 portion of mid-gut. A basal labyrinth was observed in both anterior and posterior regions of mid-gut while it was absent in middle portion of mid-gut. Thin basement membrane was observed in the 3 portions of mid-gut of third instar larvae of Sarcophag aegyptiaca.

Study on the Morphologic Variations in Colic Branches of Superior Mesenteric Artery.

Superior mesenteric artery arises from the abdominal aorta and supplies the derivatives of Midgut. Knowledge of the normal and anomalous arterial supply is important in modern abdominal surgical techniques like liver transplants, laparoscopic surgery, splenectomies, intestine transfers, penetration injuries of abdomen, resections of the small and large intestines, in radiological diagnosis and radiological abdominal interventions. A total number of 50 superior mesenteric arteries were studied in the different age group and sex by Dissection, Angiogram pictures and Surgeries. The colic branches were studied for variations in origin, course and pattern of supply.

A Case of a Preterm Infant with Prenatally Diagnosed Intrauterine Midgut Volvulus / 대한주산의학회잡지

Intrauterine midgut volvulus is a rare and potentially life-threatening congenital disease that can lead to intestinal ischemia, sepsis and peritonitis caused by bowel perforation and meconium obstruction. Early detection and immediate treatment is crucial to improve the outcome. Herein, we report a preterm infant of 30 weeks of gestation with intrauterine midgut volvulus associated with meconium peritonitis who survived after cesarean delivery and immediate postnatal surgical intervention. The outcome of in-utero intestinal volvulus depends on optimal delivery timing and adequate postnatal treatment. Therefore, prompt multidisciplinary consultation and planning with obstetricians, neonatologists and pediatric surgeons is necessary to reduce the morbidity and mortality associated with fetal midgut volvulus, especially in the preterm period.

Kazal-type serine proteinase inhibitors in the midgut of Phlebotomus papatasi

Sandflies (Diptera: Psychodidae) are important disease vectors of parasites of the genus Leishmania, as well as bacteria and viruses. Following studies of the midgut transcriptome of Phlebotomus papatasi, the principal vector of Leishmania major, two non-classical Kazal-type serine proteinase inhibitors were identified (PpKzl1 and PpKzl2). Analyses of expression profiles indicated that PpKzl1 and PpKzl2 transcripts are both regulated by blood-feeding in the midgut of P. papatasi and are also expressed in males, larva and pupa. We expressed a recombinant PpKzl2 in a mammalian expression system (CHO-S free style cells) that was applied to in vitro studies to assess serine proteinase inhibition. Recombinant PpKzl2 inhibited α-chymotrypsin to 9.4% residual activity and also inhibited α-thrombin and trypsin to 33.5% and 63.9% residual activity, suggesting that native PpKzl2 is an active serine proteinase inhibitor and likely involved in regulating digestive enzymes in the midgut. Early stages of Leishmania are susceptible to killing by digestive proteinases in the sandfly midgut. Thus, characterising serine proteinase inhibitors may provide new targets and strategies to prevent transmission of Leishmania.

Perimicrovillar membrane assembly: the fate of phospholipids synthesised by the midgut of Rhodnius prolixus

In this study, we describe the fate of fatty acids that are incorporated from the lumen by the posterior midgut epithelium of Rhodnius prolixus and the biosynthesis of lipids. We also demonstrate that neutral lipids (NL) are transferred to the haemolymphatic lipophorin (Lp) and that phospholipids remain in the tissue in which they are organised into perimicrovillar membranes (PMMs). 3H-palmitic acid added at the luminal side of isolated midguts of R. prolixus females was readily absorbed and was used to synthesise phospholipids (80%) and NL (20%). The highest incorporation of 3H-palmitic acid was on the first day after a blood meal. The amounts of diacylglycerol (DG) and triacylglycerol synthesised by the tissue decreased in the presence of Lp in the incubation medium. The metabolic fates of 3H-lipids synthesised by the posterior midgut were followed and it was observed that DG was the major lipid released to Lp particles. However, the majority of phospholipids were not transferred to Lp, but remained in the tissue. The phospholipids that were synthesised and accumulated in the posterior midgut were found to be associated with Rhodnius luminal contents as structural components of PMMs.

Immunopathological features developing in the mosquito midgut after feeding on anopheles gambiae mucin-1 / interleukin-12 cDNA immunized mice / Desarrollo de características inmunopatológicas en el intestino medio del mosquito después de alimentarse de ratones inmunizados con mucina-1 / interleucina-12 ADNc de anopheles gambiae

The mosquito midgut is the organ into which the blood meal passes and in which, within a peritrophic membrane secreted by the epithelium, the blood is retained during digestion and absorption. The mosquito midgut is lined with an actin filled microvilli that are exposed to the harsh environment of the gut lumen such as food particle abrasion, digestive hydrolases and attack by pathogens and parasites that are taken in by the blood meal. These microvilli are protected them these effects by the peritrophic matrix, the glycocalyx and the mucin proteins that line their epithelial surfaces. Immunization of BALB/c mice with AgMUC1/IL-12 cDNA has been shown to kill mosquitoes when fed on these mice. Mucin is one of the proteins produced in the mosquito midgut after a blood meal. The fine structure of the mosquito midgut epithelium interacting with immune factors such as antibodies or immune cells is of special significance for interpreting early events in the interaction between the mosquito midgut lining and the specific immune components present in the blood of AgMUC1/IL-12 cDNA immunized BALB/c mice. Following bright light microscopy, scanning electron and transmission electron microscopic observations of the features seen in mosquito midgut sections from An. gambiae mosquitoes fed on BALB/c mice immunized with AgMUC1/IL-12 cDNA, the most likely immune mechanisms responsible for mosquito killing could be cell mediated, most likely antibody dependent cellular cytotoxicity. Both necrotic and apoptotic processes that could be the cause of mosquito death were seen to take place in the cells lining the midgut epithelium.

El intestino medio es el órgano al cual pasa la sangre consumida por el mosquito y donde, mediante una membrana peritrófica secretada por el epitelio, esta sangre es mantenida durante la digestión y absorción. El intestino del mosquito está revestido por microvellosidades llenas de actina que son expuestas a las complejas condiciones en torno a la luz intestinal, tales como la abrasión producida por partículas de alimentos, hidrolasas digestivas y el ataque de patógenos y parásitos que son tomados en la sangre consumida. Estas microvellosidades se protegen de estos efectos mediante la matriz peritrófica, el glicocálix y las proteínas de mucina que revisten las superficies epiteliales. La inmunización con AgMUC1/IL-12 ADNc en ratones BALB/c ha demostrado ser útil para matar los mosquitos cuando se alimentan de estos ratones. La mucina es una de las proteínas producidas en el intestino medio del mosquito después de consumir sangre. La fina estructura del epitelio del intestino interactúa con factores inmunes tales como anticuerpos o células inmunes es de especial importancia para interpretar los eventos tempranos en la interacción entre el revestimiento del intestino medio y los componentes inmunológicos específicos presentes en la sangre de ratones BALB/c inmunizados con AgMUC1/IL-12 cDNA. Después de observar mediante microscopías de luz, electrónica de barrido y de transmisión las características de secciones del intestino medio del mosquito Anopheles gambiae alimentado de ratones BALB/c inmunizados con AgMUC1/IL-12 cDNA, mecanismos inmunes mediados por citotoxicidad celular dependiente de anticuerpos (ADCC) podrían ser los responsables de matar a los mosquitos. Los procesos necróticos y apoptóticos que pueden ser la causa de la muerte del mosquito tienen lugar en las células que recubren el epitelio del intestino medio.