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Simplified approach to umbilical remnant abnormalities.

To facilitate an understanding of abnormalities related to the umbilical remnants, the authors present a simplified classification scheme on the basis of embryologic anatomic relationships. In a type 1 remnant, the entire duct (vitelline or urachus) is patent; in type 2, only one end is patent; and in type 3, only the midportion is patent. The authors illustrate and describe various entities in terms of this classification, including patent vitelline duct, umbilical sinus, Meckel diverticulum, vitelline cyst, patent urachus, urachal sinus, urachal diverticulum, and urachal cyst. With this scheme, imaging characteristics of the types of remnant abnormalities can be predicted. The result is a cogent approach to the radiologic evaluation of the patient with a suspected umbilical remnant anomaly.

Humans↗

[A bizarre excrescence of the umbilicus in a 1-month-old child].

We report the case of an umbilical polyp, derived from omphalo-mesenteric remnants in an one-month-old female child. This rare abnormality results from a closure defect of the vitelline duct. The vitelline duct normally closes between the 5th and the 7th weeks of intra embryonic development but can lead to several pathologies in case of closure defects, giving rise to abdominal (Meckel diverticulum, vitelline cyst) or umbilical symptoms (umbilical fistula, umbilical sinus and umbilical polyp). These disorders have a 2% incidence, and may induce clinical symptoms of varied gravity ranging from clinical silence to acute abdomen. We seized the opportunity of this rare clinical observation to review the nosology of vitelline duct defects at the light of embryologic data.

Female↗

Autoradiographic study on the uptake of (3)H-6-thymidine by Fasciola hepatica.

Autoradiographic study was performed in order to know the distribution of exogenous radioactive substance, (3)H-6-Thymidine, by liver fluke, Fasciola hepatica. The worms were maintained in vitro for 1 hour, at 37 degrees C, in Tyrode solution containing (3)H-6-Thymidine. After the incubation, the worms were sectioned and autoradiographed by applying the techniques of microautoradiography. The black grains derived from labeled substance were highly accumulated in the vitelline duct and vitelline glands. Moderate amount of blackening showed in the subcuticular muscle fibers, testes, ovary, cirrus sac, oral sucker and pharynx. Slightly labeled particles were in the reticular tissue, ventral sucker, intestinal epithelium, prostate, uterus and ova. There can hardly be found the black grains in the cuticle.

Journal Article↗

New advances in human embryology: morphofunctional relationship between the embryo and the yolk sac.

Organogenesis occurs during the first 8 weeks of human embryonic development; in consequence, early human growth and development take place before and in the absence of fully developed internal organs. During this period, normal development depends on several factors, but two are imperative: nutrition and a functional transport system for the distribution of nutrients and for waste disposal. The yolk sac (YS), a highly differentiated adnexal organ, is known to accomplish this fundamental task during early pregnancy. In this review, we summarize our contribution to the understanding of early human embryology, focusing interest on analysis of the morphofunctional link that is established between the human embryo and the YS during the embryonic period. Embryos were collected from the gestational sac after salpingectomies performed on patients with singleton pregnancies occurring in the fallopian tube. Samples of YS were taken from 20 human embryos at Carnegie stages ranging from 12 to 20. The age of the embryo was estimated from data of the patient's last menstrual history and confirmed from crown-rump length measurements and morphological characteristics of the specimen. The samples were fixed in 3% glutaraldehyde and then postfixed in 2% osmium tetroxide and prepared for light, transmission, and scanning electron microscopy according to conventional techniques. The samples were examined with a Philips 301 EM and an S-4000 Hitachi field emission SEM. The yolk stalk, and the YS wall with its corresponding endodermal, mesenchymal, and mesothelial layers, were analyzed. In accordance with their morphological features, the endodermal cells are equipped with organelles to fulfill several functions that are expressed in absorption from the vitelline cavity via microvilli present into the outer cell surface, in secretion to the extracellular space, and in the synthesis of numerous proteins which are transported by the bloodstream to the embryo. The mesothelial surface is provided with cell-surface differentiation that promotes a protective coat to prevent damage from compression or friction of the YS wall against the amnios, umbilical cord, and chorionic cavity wall during growth. The mesenchyme is the main site for blood vessel formation and gives rise to a network that provides the embryo with nutrients and a means of waste disposal. A critical analysis of the role of the endodermal vesicle in the production of fluid that is accumulated in the YS, and of the role that the vitelline duct play in the exchange function between the YS and intestinal tract, is presented. We have demonstrated that the vitelline duct is not functional after week 5 because of the closure of its lumen. This finding is discussed with reference to the biological meaning of the vitelline duct and its functional period of activity, and its possible role in the physiology of exchange during the embryonic period is assessed.

Journal Article↗

Fine structure of the female reproductive ducts of Cyathocephalus truncatus (Cestoda: Spathebothriidea), from salmonid fish.

The fine structure of the ovary, ovicapt, oviduct, fertilisation canal, vitelline ducts, vitelline reservoir, ovovitelline duct, ootype and Mehlis' gland, and proximal, middle and distal parts of the uterus of the spathebothriidean cestode, Cyathocephalus truncatus (Pallas, 1781), from salmoniform fish, has been studied for the first time by transmission electron microscopy (TEM). Emphasis was given to characteristics which might shed light on the unclarified phylogenetic position of spathebothriideans, belonging among the most basal tapeworms (Eucestoda). New for cestodes is the finding of a multinucleate cell that plugs the ovicapt lumen. The morphology of the proximal part of the oviduct resembles that of the pseudophyllidean tapeworm Diphyllobothrium latum. After fertilisation in the fertilisation canal, vitellocytes of C. truncatus become associated with fertilized oocytes in the ovovitelline duct. Only one type of Mehlis' gland secretory cell is present. The eggs with electron-dense eggshells containing large pores first appear in the proximal part of the uterus. The middle portion of the uterus has well-developed uterine glands. The distal portion of the uterus has apical microtriches. Ultrastructural data on the female genital system of C. truncatus are compared and discussed with those for other cestodes. However, on the basis of available ultrastructural data it is not possible to conclude whether the Spathebothriidea are phylogenetically closer to the Caryophyllidea or to the Pseudophyllidea.

Animals↗

Ultrastructure of Pharyngostomoides procyonis Harkema 1942 (Diplostomatidae). II. The female reproductive system.

Several components of the female reproductive system of Pharyngostomoides procyonis, including the vitellaria and vitelline duct, ovary and oviduct, Laurer's canal, and Mehlis' gland and associated ducts, were observed with the electron microscope. Vitelline follicles contain cells in various stages of development. Mature vitelline cells contain membrane-delimited clusters of vitelline globules near the plasma membrane. Cilia are present in the vitelline duct. The ovary contains germ cells in various stages of maturation. Oogonia are found in the peripheral region. Mature oocytes contain numerous dense bodies near the plasmalemma. Also included in the cytoplasm of mature oocytes are "nucleolus-like bodies," myelin-like bodies, and mitochondria containing dense granules and few cristae. The epithelium of the oviduct is ciliated. Sperm are present in the oviduct and in Laurer's canal. Two types of secretory cells found in Mehlis' gland are described.

Animals↗

[Ultrastructure of genital system ducts of Diphyllobothrium latum (Cestoda:Pseudophyllidae): the ducts of the female reproductive system].

The components of the female reproductive system of Diphyllobothrium latum, including ovary, ovicapt, oviduct, vitelline ducts, vitelline reservoir, vagina, seminal receptacle, ootype with unicellular Mehlis's gland, ootype-uterine duct and uterus were observed with the electron microscope. The epithelium of the female reproductive system ducts consists of a nucleate syncytial layer. Structural differences in apical surface of the ducts, the number of nuclei and organoids in syncytial layer as well as the number of underlaid muscles were revealed. The regional differentiations of the uterus wall were registered. The middle and distal region of uterus was covered with microtriches. The filamentous microtriches were observed in apical surface of vagina. The epithelium of seminal receptacle and distal region of uterus were underlaided by the powerful muscle layers. The fertilization canal was revealed. It was shown that the formation of egg shells implemented by the deposit of vitelline globules in their surface in the ootype-uterine duct. Structural and functional differences of different parts of female apparatus in various groups of cestodes are conditioned by species biology.

Animals↗

An umbilical polyp in an infant.

The persistence at birth of the omphalomesenteric (vitelline) duct may result in life-threatening consequences. Early identification of this congenital anomaly is essential for prompt surgical treatment to eliminate the risk of prolapse and herniation. A neonatal umbilical polyp may indicate the presence of an omphalomesenteric duct remnant. We describe the diagnosis and surgical treatment of an infant with an umbilical polyp. We also present an overview of the diagnosis and treatment of vitelline duct remnants and their associated anomalies.

Diagnosis, Differential↗

Volume and vascularity of the yolk sac assessed by three-dimensional and power doppler ultrasound.

The yolk sac is an organ of increasingly recognized importance in the initial mechanisms of pregnancy maintenance and the early growth and welfare of the embryo. The aim of our study was to assess the vascularity of the yolk sac and vitelline duct in 150 patients between the 6th and 10th weeks of normal, and uncomplicated pregnancies who were scheduled for termination of pregnancy for psychosocial reasons and 130 complicated pregnancies. In same patients volume of the yolk sac was assessed using Combison 530 3D Voluson, Medison-Kretz Company. Overall visualization rate for yolk sac vessels was 80,38%. The highest visualization rates were obtained in the 7th and 8th weeks of gestation reaching values of 90,71 %. In the same period the visualization rates of the vitelline duct arteries were 87,71% and 91,28% respectively. A characteristic waveform profile included low velocity (5,8+/-1,7 cm/s) and absence of diastolic flow which was obtained from all examined yolk sacs. The PI showed the mean value of 3,24+/-0,94 without significant changes between subgroups (p>0,05). Vitelline vessels showed similar PSV (5,4+/-1,8 cm/s) and PI values (3,14+/0,91) (p>0,05) to that obtained from the yolk sac. Three types of abnormal vascular signals were derived from the yolk sac in patients with missed abortion (n=32): irregular blood flow (n=6), permanent diastolic flow (n=2) and venous blood flow signals (n=5). However, in the most of the patients (n=19) blood flow signals could not have been extracted from these early embryonic structures. Using three-dimensional ultrasound we found a positive correlation between gestational age and volumes of the gestational and yolk sac until 10 weeks gestation. At the end of the first trimester yolk sac volume remained constant, while gestational sac volume continued to grow. It seems that changes in both yolk sac appearance (size, shape, volume and echogenicity) and vascularization are probably a consequence of poor embryonic development or even embryonic death, rather than being a primary cause of an early pregnancy failure.

Female↗

Neotropical Monogenoidea. 50. Oviparous gyrodactylids from loricariid and pimelodid catfishes in Brazil, with the proposal of Phanerothecioides n. g., Onychogyrodactylus n. g. and Aglaiogyrodactylus n. g. (Polyonchoinea: Gyrodactylidea).

The diagnosis of Phanerothecium Kritsky & Thatcher, 1977 is amended, and Phanerothecioides n. g., Onychogyrodactylus n. g. and Aglaiogyrodactylus n. g., all comprised of oviparous gyrodactylids (Monogenoidea: Polyonchoinea), are proposed to accommodate 11 of the 15 species (14 new to science) herein described and/or reported from loricariid and pimelodid catfishes (Teleostei: Siluriformes) in Brazil: Phanerothecium harrisi Kritsky & Boeger, 1991, P. spinatoides n. sp. and P. deiropedeum n. sp. all from Hypostomus spp.; P. spinulatum n. sp. from Hypostomus cf. regani; Phanerothecioides agostinhoi n. g., n. sp. (type-species) from Hypostomus spp. and Pseudoplatystoma fasciatum; Onychogyrodactylus sudis n. g., n. sp. (type-species) and O. hydaticus n. sp. both from Ancistrus multispinus; Aglaiogyrodactylus forficulatus n. g., n. sp. (type-species) from Kronichthys lacerta; A. pedunculatus n. sp. from Hisonotus sp.; A. guttus n. sp. from Pseudotothyris obtusa; A. salebrosus n. sp., A. conei n. sp. and A. ctenistus n. sp. all from Pareiorhaphis parmula; and A. calamus n. sp. and A. forficuloides n. sp. both from Schizolecis guntheri. Phanerothecioides n. g. is characterised by oviparous forms lacking superficial and deep haptoral bars and pregermarial vitelline follicles, and by having a conspicuous testis in adult specimens, a syncytial prostatic gland, a reduced copulatory sac and vitelline ducts in the form of an inverted 'U'. Onychogyrodactylus n. g. is differentiated from all other oviparous gyrodactylid genera by its members having a spine-like accessory sclerite enclosed in a separate pouch associated with the terminal male genitalia. Species of Aglaiogyrodactylus n. g. possess H-shaped vitelline ducts and a complex accessory piece and sclerotised or non-sclerotised male copulatory organ enclosed within the copulatory sac.

Animals↗

Trypan blue accumulation in the embryonic gut of rats and mice during the teratogenic phase.

Four to 48 hours after iv and sc administration of teratogenic doses of trypan blue to rats and mice the uterus was removed and rapidly frozen, after having been placed in a horizontal plane, and frozen sections were attached to tape and dried at a low temperature. By this procedure embryos and placental structures were present in the same sections and loss or redistribution of the dye was minimized. The dye was found in the yolk-sac cavity and to be accumulated in the visceral (proximal) endoderm. It was also acculmulated in the embryonic endoderm--forming the embryonic gut. This accumulation occurred after the administration of the trypan blue up to the time of closure of the vitelline duct, which occurs at 11 days postconception in rats and 9.5 days in mice. None was found when injection was made after this closure. No dye was detected in the ecto- and mesodermal layers. The period of embryonic uptake of trypan blue largely corresponds with the period of teratogenic sensitivity in these species as reported by others.

Animals↗

[Persistence of the omphalomesenteric duct. Childhood differential diagnosis of umbilical granuloma].

The omphalomesenteric duct is an embryonic structure which communicates the vitelline duct with the midgut. It normally disappears between the fifth and ninth weeks of intrauterine life. Anomalies related with the total or partial absence of this involution are show in 2 % of the population. We report a case of persistence of the omphalomesenteric duct and review the bibliography to establish the differences between this anomaly and umbilical granuloma, which is the main differential diagnosis.

Diagnosis, Differential↗

[Fine structure of the female reproductive system in Sobolevicanthus gracilis and Cloacotaenia megalops (Cestoda: Cyclophyllidea)].

The fine structure of the female reproductive organs and ducts in two cyclophyllidean cestodes was studied by transmission electron microscopy. All the studied ducts (vitelline, fertilization and vaginal ducts, and oviducts) as well as the uterine and ootype walls have the luminal surface elevated to form apical cytoplasmic lamellae and are surrounded by bands of circular muscules, which are attached to the basement layer. The structure of the studied ducts epithelium corresponds to the pattern described in other ducts of the cestode genital system, namely a nucleate syncytial layer. An exception is the vagina Sobolevicanthus gracilis, in which the surface is lined with not numerous atypical microtriches. The comparison of our results and the data reported for other species is given. It is found out that in different species of cestodes forming oligolecital eggs, there are observed various uterine structures and diverse contacts between the eggs capsules and the uterine epithelium. The formation of special structures and contacts is the evolutionary way from the extrauterine type to more progressive intrauterine type of embryo development in cestodes.

Animals↗

Intestinal obstruction caused by omphalomesenteric duct remnant: usefulness of laparoscopy.

The anomalies related to omphalomesenteric duct remnant constitute an uncommon cause of intestinal obstruction, of which Meckel"s diverticulum and its variants represent the most important clinical presentation. In most cases they are asymptomatic and usually affect young patients. When symptomatic, they usually present episodes of gastrointestinal bleeding or acute abdomen syndromes caused by strangulation of intestinal loops as a result of fibrous intraabdominal remnants or inflammation produced by the diverticulum. In most cases, the unexpected presence of these alterations makes intraoperative diagnosis necessary. Treatment is surgical and consists in exeresis of the diverticulum or the fibrous band causing the clinical picture. We report two cases of persistence of the vitelline duct resolved by laparoscopic approach.

Adolescent↗