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At least 73 records · Page 4Linked to original sources
PubMed2007

Does moderate celiac axis stenosis identified on preoperative multidetector computed tomographic angiography predict an increased risk of complications after pancreaticoduodenectomy for malignant pancreatic tumors?

OBJECTIVES: To identify any association between celiac artery compromise found on computed tomographic angiography and the incidence of postoperative and perioperative complications. METHODS: The computed tomographic angiograms of 36 patients who underwent the Whipple procedure for pancreatic adenocarcinoma were examined retrospectively. The association between the results and surgical course was investigated. RESULTS: Twelve patients (33%) had significant postoperative complications. Ten (28%) had evidence of celiac artery stenosis. Stenosis ranged from 20% to 60%. There was no evidence of a difference between the 2 groups. CONCLUSION: There seems to be no evidence of an increased risk of postoperative or perioperative complication in patients undergoing the Whipple procedure, with a celiac stenosis of up to 60%.

Adenocarcinoma↗
PubMed1990

Embryologic fusion planes and the spread of cutaneous carcinoma: a review and reassessment.

It has long been held that embryologic fusion planes influence the spread of skin cancer. Embryologic fusion planes have been implicated in the depth of invasion, horizontal spread, and recurrence of cutaneous carcinoma. However, these structures have never been studied in detail. A review of the surgical literature reveals considerable confusion regarding the exact nature, location, and tumor interactions of these fusion planes. We review the gross and microscopic development of sites of embryologic fusion. We examine histologic sections through fusion sites in normally developed adult and fetal fresh cadaver specimens. Our studies, supported by our review of developmental anatomy, indicate that fusion planes do not persist as identifiable anatomic structures that would influence tumor spread.

Adolescent↗
PubMed1982

Anatomical-embryological correlates in atrioventricular septal defect.

Recent embryological studies have supported the consideration that the ventricular septum is multifocal in origin. These data have also provided excellent correlation of the morphology of malformed hearts with their embryology. In particular, atrioventricular septal defect correlates accurately with these observations on ventricular septation. Many of the names given to atrioventricular septal defect (for example ostium primum, persistent atrioventricular canal, endocardial cushion defect) indicate attempts at correlating the anatomy with embryology. None of these has been very convincing. In the light of this uncertainty, this review considers briefly the anatomy of the malformation and its ontogeny, and presents a hypothesis of the development of atrioventricular septal defect. Although there is almost always a communication above the atrioventricular valves, the malformation lies in the ventricular, not the atrial septum. Hearts with inlet septal defect without interatrial communication represent one end of the spectrum of anomalies, and those with common atrioventricular orifice, in which Fallot's tetralogy or single outlet heart may be associated, mark the other end. The outflow tract malformations are not randomly associated, but are points in a huge range of cardiac malformations.

Heart Septal Defects↗
PubMed1994

Hypoechogenic embryologic ventral aspect of the head and uncinate process of the pancreas: in vitro correlation of US with histopathologic findings.

PURPOSE: To evaluate the hypothesis that hypoechogenicity of the embryologic ventral aspect of the head of the pancreas is due to diminished fat content. MATERIALS AND METHODS: Ultrasound and histopathologic findings in 13 pancreatic autopsy specimens were compared, and the prevalence of areas of hyperattenuation of the embryologic ventral aspect of the head of the pancreas at computed tomography (CT) was studied. RESULTS: In vitro examination of pancreatic autopsy specimens showed this variant in seven (54%) of the 13 specimens, and histopathologic correlation confirmed that there is diminished fat content corresponding to the hypoechoic portion of the head of the pancreas. This difference in attenuation was visible on 21 (22%) of 96 CT scans. There was a statistically significant (P < .05, r = .212) increase in the prevalence of this finding with increasing age. CONCLUSION: Hypoechogenicity of the embryologic ventral aspect of the head of the pancreas is due to diminished fat content. This difference in attenuation is also commonly seen on CT scans.

Adipose Tissue↗
PubMed1993

Syndactylies and polydactylies: embryological overview and suggested classification.

In 1978, Temtamy and McKusick classified isolated, non-syndromic polydactyly and syndactyly, using a logical anatomical approach, into five distinct types for each group. Since then, there have been considerable advances in the molecular embryology of the developing limb bud. These include the proposal that retinoic acid and/or related retinoids are the morphogens responsible for the morphogenetic gradient giving rise to anterior-posterior pattern formation of the limb bud, the suggestion that the HOX4 complex and other homeotic genes may also be involved in patterning, and a greater understanding of other mechanisms such as programmed cell death in the shaping of the final hand and foot. This paper briefly reviews the molecular embryology of limb development and outlines the 'end-organ responsiveness' of the limbs to a variety of single-gene mutations. An alternative classification of syndactylies and polydactylies is suggested. It is still too early to match specific defects to individual genes with precision, and it is obvious that many important developmental genes remain to be identified; nevertheless, it is envisaged that clues from molecular embryological studies will become increasingly more useful.

Animals↗
PubMed2006

The history of scientific endeavors towards understanding hagfish embryology.

Due to their curious phylogenetic position and anatomy, hagfishes have attracted the interest of zoologists, especially in the context of vertebrate evolution. Embryological information on these animals is now also needed in the field of evolutionary developmental biology (Evo-Devo), as it is expected to provide hints about the origin of vertebrate traits, whether the hagfishes are an in-or outgroup of vertebrates. This review summarizes the importance of hagfish embryology from a phylogenetic perspective, and the history of attempts to obtain hagfish eggs and embryos. Clearly, the main difficulty associated with these animals is their deep-sea habitat. To circumvent this problem, this review also discusses the future prospects for obtaining embryological material, both from the wild and in the laboratory.

Animals↗
PubMedDate not supplied

The embryology of congenital heart defects.

The embryological development of the heart is an awesome and complex process. The heart is formed from groups of cells that coalesce into sheets of tissue. These sheets fuse to form a tube that grows into the atria and ventricles. The twists and turns of the developing heart tissue and the simultaneous septation of atria, ventricles, and truncus, along with a shifting of the atrioventricular canal and conus then position the portions of the heart in alignment to allow normal blood flow. Errors at any stage of embryological formation can result in specific congenital defects. Understanding the development of the heart in utero can provide the pediatric nurse a basis for understanding the physiological effects of embryological failures that result in congenital heart defects in the infant and child.

Embryonic and Fetal Development↗
PubMed2003

[Clinical and embryological approaches to nasal dermoid sinus cysts].

Nasal dermoid sinus cyst (NDSC) is an uncommon congenital lesion presenting as a large panel of midline craniofacial anomalies. Thirty children with nasal midline masses and/or sinus ostia were surgically treated in the pediatric ENT and cervicofacial surgery department of Trousseau's children's hospital (Paris-France) between 1995 and 2002. All our patients underwent radiological evaluation including CT scan (including axial and coronal planes) and/or MRI (in all three planes) in search of intracranial extension. Thirteen of our patients presented with a midline cyst only, ten had nasal pit only, and seven had combined anomalies. Preoperative radiology and surgery showed an intracranial extension in 3 patients, which exhibited contact of the cyst with the dura. Recurrence being expected if any dermal tissues were left in place, "one-time-excision management" was the rule. CT and MR imaging features were reviewed. The external rhinoplasty procedure resulted in a wide surgical approach, low recurrence and good esthetic results. The embryological and anatomical origins of NDSCs are reviewed. Development of NDSC during embryological development implicates two necessary and sufficient conditions: competence of the ectodermal and mesectodermal cells to form dermoid tissue with epithelial-mesenchymal interactions, and a topographical site of ectodermal inclusion, which fits well with the various clinical presentations of NDSCs. We propose to distinguish NDSCs of anterior topography, located at the anterior skull base level from the basal NDSCs, located at the middle skull base level. We reviewed the various localizations of NDSCs, revisiting a forgotten embryological theory, which unify the various clinical localizations of anterior NDSCs.

Adolescent↗
PubMed1989

[Embryologic and anatomic considerations on the normal and pathologic formation of the cardiac septum. I. Interauricular septum].

A brief presentation of the normal embryological development of the human interatrial septum is made. The anatomical expression of each of its embryological components is described. Our classification of interatrial septal defect is enriched by their more precise anatomical description and by making a more correct morphogenetic interpretation, based on new information obtained by means of experimental embryology. Emphasis is made that absence of the interatrial septum does not preclude the diagnosis of viscero-atrial situs.

Heart Atria↗
PubMed1993

Embryological study of nasal cavity development in human embryos with reference to congenital nostril atresia.

An infant with congenital absence of the nostrils, incomplete prolabium, incomplete premaxilla, nasal cavity without septum, and cleft palate is presented. To clarify the embryological development of the nostril, serial sections of many embryos and fetuses of various stages were examined. Recanalization of the nostril, resulting from resorption of the temporary nasal epithelial plug, was observed in a 13- to 15-week fetus. Although textbooks of human embryology describe its occurrence in the 6th month or 24th week of fetal life. This finding suggests that the embryological cause of congenital nostril atresia, in the present case, may have been persistence of the plug.

Female↗
PubMed1999

The U.K. Human Fertilisation and Embryology Authority. How it has contributed to the evaluation of assisted reproduction technology.

The Human Fertilisation and Embryology Act of the United Kingdom was passed in 1990, leading to the formation of the Human Fertilisation and Embryology Authority (HFEA), the first statutory body to regulate and control assisted conception anywhere in the world. The principal function of the HFEA is to license and monitor clinics that carry out in vitro fertilization (IVF), donor insemination (DI), and embryo research. Information on over 135,000 treatment cycles, 20,000 pregnancies, and 25,000 babies following IVF has now been collected as part of the regulatory process, and these data have permitted unbiased and accurate evaluation of treatment efficacy using pregnancy and live-birth rates. The treating clinics are required by law to provide information on the outcome of all births, including neonatal mortality and congenital malformations, but there is no systematic validation of these data using medical records or any follow-up of treated women, or babies, over time. In addition, the strict confidentiality of data supplied to the HFEA means that outside researchers have been unable to access the database for research projects. Thus, at the present time, it is not possible to evaluate the long-term safety of assisted conception procedures using HFEA data. There is reasonable scientific evidence to justify full investigation of the health of both treated women and resulting children. Particular health outcomes requiring evaluation include obstetric complications, preterm births, cerebral palsy, and cancer. The HFEA has recognized the need for follow-up studies and is currently investigating ways of enabling research projects using HFEA data to be undertaken.

Congenital Abnormalities↗
PubMed1997

The role of the Human Fertilisation and Embryology Authority.

The recent publicity surrounding Diane Blood and the theoretical possibility of cloning human beings has highlighted yet again the important role of the Human Fertilisation and Embryology Authority (HFEA). It will be remembered that Mrs Blood sought to establish a right to be inseminated with her dead husband's sperm without his written consent. The HFEA, following the strict letter of the Human Fertilisation and Embryology Act 1990, withheld its permission for the procedure. Following a Court of Appeal decision to allow Mrs Blood access to treatment abroad the Department of Health commissioned an independent ethicist to address the relevant issues. The use of such an expert which avoids any potential conflicts of interest, when the body has many members with the relevant expertise, is another example of how important the HFEA's integrity is viewed. It strives to act in an exemplary manner in the often hostile environment of uninformed public concern and against a backdrop of a statutory framework that is generally thought to suffer from a democratic deficit. This article will provide an outline of HFEA's background, structure and manner of operation in an attempt to demonstrate that it offers a model of regulation for the new reproductive technologies despite the constraints it faces.

Embryo Research↗
PubMed2005

Some problems challenging the UK's Human Fertilisation and Embryology Authority.

The UK's Human Fertilisation and Embryology Authority (hereafter the HFEA) is a regulatory body facing growing pressures and difficulties. Like any regulatory body, it faces the challenge of regulating with sufficient expertise, legitimacy, and contemporaneity. This challenge is, however, exacerbated by the fact that it seeks to regulate some of the most controversial and rapidly changing technologies of our time. Its decisions and jurisdictional assumptions face increasing challenge. In addition to the multitude of cases brought against it, the HFEA's actions recently led a House of Commons Select Committee to pointedly declare that "democracy is not served by unelected quangos (quasi-autonomous non-governmental organizations) taking decisions on behalf of Parliament". While endorsing the general need to review the legislation under which the HFEA operates (the Human Fertilisation and Embryology Act 1990), this paper will argue that the HFEA was correct in interpreting its jurisdiction to encompass the technique used to produce Dolly the sheep. This paper thereby defends the key feature of the approach of the House of Lords in the recent case of R (Bruno Quintavalle on behalf of the ProLife Alliance) v Secretary of State for Health [2003] UKHL 13.

Cloning, Organism↗
PubMed2002

Survey of gross anatomy, microscopic anatomy, neuroscience, and embryology courses in medical school curricula in the United States.

Directors of courses in the basic anatomical sciences in allopathic and osteopathic medical schools in the United States were surveyed regarding the present composition of their courses. Results indicate the majority of gross anatomy courses are in the range of 126 to 200 total course hours, and that laboratory dissection is a key component of these courses. The majority of microscopic anatomy courses are in the range of 61 to 100 total course hours, generally divided equally between lecture and laboratory components. Additionally, despite the availability of computer technology, microscopes are still used in the vast majority of microscopic anatomy courses. The majority of neuroscience courses are in the range of 71 to 90 total course hours, with most of these hours devoted to lectures. Embryology is usually taught in conjunction with gross anatomy, although some schools present it with the microscopic anatomy course or as a separate course. Most embryology courses are in the range of 6 to 20 total course hours, with only a few having a laboratory component.

Anatomy↗
PubMed1996

Computer morphing of scanning electron micrographs: an adjunct to embryology teaching.

Traditional embryology courses demand considerable expenditure of time and effort from students to master the spatial awareness skills necessary to create three-dimensional mental images from two-dimensional serial sections. Then students must imagine a movie sequence of the changes which take place during normal development. Further steps are required to relate this information to the clinical situation. As more medical and dental schools move towards problem-based curricula, more efficient methods of improving understanding of embryology are needed. The development of many organs can be studied using scanning electron micrographs of embryos at different ages. These high quality images are more easily interpreted by our students than histological sections and the understanding achieved more readily applied to clinical problems. Still more beneficial would be the provision of moving images showing the actual changes happening. We decided to use computer morphing techniques to prepare movie sequences showing development of the face and plate. For each, four scanning electron micrographs of appropriately-sized sheep embryo heads were taken at the same magnification and orientation to use as start and end points of morphing sequences. After using retouching techniques to colour the separate processes, further sequences were prepared. The discipline of maintaining the same magnification throughout and the possibility of directly observing changes between stages revealed some surprising growth patterns. This technique is adaptable to any area of biological development where pre- and post-illustrations are available. Animations can be presented on computer or on video and incorporated into programs. Student feedback has been very favourable.

Animals↗
PubMed1998

A new episcopic method for rapid 3-D reconstruction: applications in anatomy and embryology.

The topographic relations of complex structures and the morphogenesis of organ systems can only be fully understood in their three-dimensional context. Three-dimensional (3-D) reconstruction of physically sectioned specimens has become an indispensable tool in modern anatomical and embryological research. Teaching also makes increasingly use of 3-D representations, in particular in the case of embryonic systems that undergo complicated transformations of form and shape. At present no cheap and simple technique is available that generates accurate 3-D models of sectioned objects. In this study we describe a novel technique that rapidly provides faithful 3-D models of sectioned specimens. The images are captured directly from the cutting surface of the embedding block after each sectioning and "on block" staining step. Automatic image processing generates a stack of binary images of the specimen contour. Binary images of internal structures are obtained both by automatic segmentation and manual tracing. Since these image series are inherently aligned, they can be reconstructed three-dimensionally without time-consuming alignment procedures. The quality and the flexibility of the method are demonstrated by reconstructing three kinds of specimens of different histological composition and staining contrast: a 4 mm mouse embryo together with several of its inner organs, a cavernous sinus region of a human infant, and a segment of a human carotid artery. Very short processing times and the faithful representation of complex structural arrangements recommend this technique for routine use in morphological research and for creating embryologic teaching models or 3-D embryonic staging series.

Anatomy, Cross-Sectional↗
PubMedDate not supplied

[On the 60th anniversary of the Department of Embryology of Moscow State University].

The Department of Embryology of Moscow State University is 60 years old on September 1, 2000. This is not all that old, especially in comparison with the almost 250-year history of the university itself or the 150-year history of embryology in Russia, but it is sufficient, in looking back, to grasp our present situation in the common flow of events and time.

Embryology↗
PubMed2001

Consequences of the Spemann-Mangold organizer concept for embryological research in Russia: personal impressions.

The impact of the organizer concept on Russian experimental embryology is shortly reviewed. Attempts to study embryonic induction in Russia may be grouped into embryological and biochemical approaches. This paper provides a framework for, and overvalue of, the contributions of Russian biologists to the problem of embryonic induction. Two model systems--lens and neural inductions--are of special significance to modern developmental biologists. Moreover, the study of eye lens induction actually gave rise to research on developmental mechanics in Russia. This was one of the reasons why we limited this article to these two model systems. After retrospective consideration of the results of the search for possible lens-inducing factor candidates, the discussion turns towards some of the examples of neural-inducing agents detected in embryonic tissues and the new questions raised by the progress that has been made in the analysis of the Spemann-Mangold organizer.

Animals↗