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S Velut

Publications and source records attributed to S Velut.

At least 19 recordsLinked to original sources
PubMed2006

The persistent left superior vena cava: anatomical study, pathogenesis and clinical considerations.

The persistence of a left superior vena cava (LSVC) is an intrinsically cardiac anomaly, which can lead to serious complications during catheterization via the subclavian or internal jugular vein. We found this anomaly during dissection associated with an abnormal origin of the vertebral artery originating from the aortic arch between the left common carotid and subclavian arteries. The LSVC coursed towards the right atrium through a very dilated coronary sinus ostium. No abnormality of the azygos system was found. A thorough anatomic description was then made with external and internal morphology. The embryonic development and variations are described. Radiological and clinical implications are discussed.

Aged↗
PubMed2005

A cultivation technique for E. coli fed-batch cultivations operating close to the maximum oxygen transfer capacity of the reactor.

A cultivation strategy combining the advantages of temperature-limited fed-batch and probing feeding control is presented. The technique was evaluated in fed-batch cultivations with E. coli BL21(DE3) producing xylanase in a 3 liter bioreactor. A 20% increase in cell mass was achieved and the usual decrease in specific enzyme activity normally observed during the late production phase was diminished with the new technique. The method was further tested by growing E. coli W3110 in a larger bioreactor (50 l). It is a suitable cultivation technique when the O2 transfer capacity of the reactor is reached and it is desired to continue to produce the recombinant protein.

Bioreactors↗
PubMed2005

[Duplication of the inferior vena cava: anatomical dissection and clinical implications].

The duplication of the inferior vena cava is often incidentally discovered during radiological studies. The presence of this anomaly can be mistaken for retroperitoneal adenopathy. Its knowledge allows to avoid hemorrhagic complications during retroperitoneal surgery. An anatomical dissection of a duplication of the inferior vena cava is presented. Embryogenesis and variations are described. Radiological and clinical implications are discussed.

Aorta, Abdominal↗
PubMed2004

Intra-operative mapping of the subcortical visual pathways using direct electrical stimulations.

Despite the risk of postoperative visual field defect following surgery within the temporo-parieto-occipital region, visual mapping has rarely been described, in particular at the subcortical level. In this report, we successfully performed a subcortical mapping of the visual pathways using intra-operative electrical stimulations (IES), during surgery under local anesthesia for a low-grade glioma invading the whole temporal lobe and the temporo-occipital junction. The optic radiations then constituted the posterior and deep functional boundary of the resection, avoiding the occurrence of a post-operative hemianopsia, in spite of an asymptomatic quadrantanopsia. This preliminary experience illustrates the possibility to use intra-operative direct electrical stimulation during surgery of lesions involving the posterior afferent visual system, in order to identify and then preserve the visual pathways, as previously reported for sensorimotor and language subcortical fibers.

Adult↗
PubMed2002

Production of heterologous thermostable glycoside hydrolases and the presence of host-cell proteases in substrate limited fed-batch cultures of Escherichia coli BL21(DE3).

Metabolic stress is a phenomenon often discussed in conjunction with recombinant protein production in Escherichia coli. This investigation shows how heterologous protein production and the presence of host cell proteases is related to: (1) Isopropyl-beta- D-thiogalactopyranoside (IPTG) induction, (2) cell-mass concentration at the time of induction, and (3) the presence of metabolites (glutamic acid or those from tryptone soy broth) during the post-induction phase of high cell density fed-batch cultivations. Two thermostable xylanase variants and one thermostable cellulase, all originating from Rhodothermus marinus, were expressed in E. coli strain BL21 (DE3). A three-fold difference in the specific activity of both xylanase variants [between 7,000 and 21,000 U/(g cell dry weight)], was observed under the different conditions tested. Upon induction at high cell-mass concentrations employing a nutrient feed devoid of the metabolites above, the specific activity of the xylanase variants, was initially higher but decreased 2-3 h into the post-induction phase and simultaneously protease activity was detected. Furthermore, protease activity was detected in all induced cultivations employing this nutrient feed, but was undetected in uninduced control cultivations (final cell-mass concentration of 40 g/l(-1)), as well as in induced cultivations employing metabolite-supplemented nutrient feeds. By contrast, maximum specific cellulase activity [between 700 and 900 U/(g cell dry weight)] remained relatively unaffected in all cases. The results demonstrate that detectable host cell proteases was not the primary reason for the decrease in post-induction activity observed under certain conditions, and possible causes for the differing production levels of heterologous proteins are discussed.

Bacteriological Techniques↗
PubMed2002

Anatomical study of the length of the human intestine.

Although preoperative assessment of the length of the intestine may be of interest to avoid postoperative consequences of large intestinal resection, measurements of the intestine are quite rare and results variable in the literature. This anatomical study aimed to assess the length of the different intestinal segments, their variation and their correlation with sex, age, weight and height. Two hundred non-fixed adult cadavers (100 men, 100 women) who willingly gave their bodies for scientific purposes were studied. The post mortem average length of the whole intestine was 795.5+/-129 cm and was significantly longer in men and in young subjects. It was correlated with the subject's weight but not height. Multivariate analysis demonstrated that the factor showing the strongest correlation with intestinal length was body weight. This latter parameter may be useful in the preoperative assessment of intestinal length.

Adult↗
PubMed2002

[Hemangiopericytoma of the infratemporalis fossa: a multi-operated patient].

Hemangiopericytoma (HPC) was diagnosed in a 65-year-old man in 1991. Initially the tumor was located in the maxillary sinus. Resection was followed by multiple recurrences involving the infratemporalis fossa (ITF), the nasopharyngeal region, and the right tonsillar region. Over a 10-year-old period, the histology pattern remained unchanged. Multiple approaches, as described in the literature, were used for resection depending on the site of the recurrence. To data, no malignant structure has been identified. Pain and cranial nerve deficits (V2, V3) have been the main squeleae. This case points out the limitations of radical resection because of the difficulty of the approach to this anatomic region. CT scan must be performed to choose the best access route depending on the primary site of the tumor and its extension.

Aged↗
PubMed2000

Microanatomy of the pericallosal arterial complex.

OBJECT: The pericallosal arterial complex supplies the callosal and pericallosal regions, as well as the anterior two thirds of the medial and superomedial aspects of both hemispheres. It is composed of the pericallosal artery (that is, the segment of the anterior cerebral artery located distal to the anterior communicating artery [ACoA]) and the median callosal artery (or third pericallosal artery), which originates from the ACoA. This system was studied in 46 specimens (23 human cadaver heads) injected with colored latex. METHODS: After being injected with colored latex, embalmed, and bleached, the specimens were studied with the aid of optic magnification. The pericallosal artery was found to be divided into four segments (A2-A5 in the proximodistal direction). After giving rise to central, callosal, and cortical branches, it terminated near the splenium of the corpus callosum as the posterior pericallosal artery, or on the precuneus as the inferomedial parietal artery. CONCLUSIONS: The authors propose a logical classification of the different variations in the pericallosal arterial complex based on embryological development. This complex can be considered a hemodynamic solution to an abnormal regression of one of its parts, which is balanced by the development of supplemental channels from other parts.

Anterior Cerebral Artery↗
PubMed2000

[Cerebro-meningeal hemorrhage secondary to ruptured vascular malformation during pregnancy and post-partum].

Thirty two new cases of vascular malformations discovered during pregnancy were reviewed in a multicentric retrospective study and compared to the literature. The authors studied both the influence of pregnancy and post-partum on cerebral vascular malformations and the corresponding neurosurgical and obstetrical management. The relative frequencies of arteriovenous malformations (AVMs) and arterial aneurysms (AAs) is the same for pregnant and non-pregnant women. Pregnancy does not increase the risk of first bleeding of vascular malformations but the risk of re-bleeding is increased for AVMs. The bleeding of a vascular malformation is more strongly correlated to age than to parity. The mean maternal age at the time of rupture is greater for AAs than for AVMs, as it is in the general population. The bleeding of a vascular malformations occurs more frequently during the second and third trimesters of pregnancy than in the first one and in the post-partum. Labor and delivery are not great-risk-periods. Management of vascular malformation in pregnant woman is proposed as follow : --a ruptured AA or AVM is managed as it is in non-pregnant woman, whatever the gestational age; no fetal extraction needs to be performed except ed if the rupture occurs at the very end of the pregnancy;--an non-ruptured AVM discovered during pregnancy is treated after delivery; an non-ruptured AVM that never bled before pregnancy is managed in the same way that an non-ruptured AA.

Aneurysm, Ruptured↗
PubMed1998

Microanatomy of the hypophyseal fossa boundaries.

OBJECT: The authors studied the heads of 17 adult cadavers and one fetus to clarify the anatomy of the sellar region, particularly the lateral boundaries of the hypophyseal fossa. METHODS: Vascular injections and microdissection or histological techniques were used in this study. The roof of the cavernous sinuses and diaphragma sellae were part of a single horizontal dural layer that joined the two anterior petroclinoid folds. Laterally, the direction of this layer changed; it became the lateral wall of the cavernous sinus and joined the dura mater of the middle cerebral fossa. On the midline, this layer ballooned toward the sella through the diaphragmatic foramina, created a dural bag containing the hypophysis, and attached to the inferior aspect of the diaphragma sellae. As a consequence, no straight sagittal dural wall existed between the pituitary gland and cavernous sinus; the lateral border of the hypophyseal fossa was part of this anteroposterior and superoinferior convex bag. The authors stress the importance of the venous elements of the region and discuss the structure of the cavernous and coronary sinuses. CONCLUSIONS: Invasion of the cavernous sinus makes surgery more risky and difficult and may necessitate modification of the surgical treatment plan. The preoperative diagnosis of cavernous sinus invasion is thus of great interest, but the possibility of normal lateral expansions of the pituitary gland must be kept in mind. A lateral expansion of this gland into the cavernous sinus was encountered in 29% of the specimens, and an adenoma that developed in such an expansion could easily mimic cavernous sinus invasion.

Adult↗
PubMed1998

[Development of the corpus callosum (CC)].

Corpus callosum embryology can be divided into three parts: during "commissuration", a cellular mass develops between the two telencephalic vesicles. The primitive lamina terminalis corresponds to the closing point of the anterior neuropore. Its dorsal part grows and forms the lamina reunions (6-8 intra uterine weeks, IUW). From ventral to dorsal, this lamina reunions gives rise to the area praecommissuralis (origin of the anterior commissure), to the primordium hippocampi (10 I.U.W., fornix), and to the massa commissuralis (10 S.I.U., corpus callosum). Fibers arising from the developing hemispheres run through this primitive corpus callosum. The growth of the corpus callosum follows the expansion of the hemispheres, in a rostro-caudal and then dorso-ventral circular movement. The last part of the corpus callosum to form is the rostrum. Maturation occurs postnatally, and corresponds to axonal elimination, and myelination, progressively changing the callosal connection pattern of the newborn and infant into the adult pattern.

Animals↗
PubMed1998

[Morphologic anatomy of the corpus callosum].

The corpus callosum is a neopallial commissure. In inferior vertebrates, the pallial commissures are essentially represented by the anterior commissure. The corpus callosum appears in mammals only. Eutherians alone have a corpus callosum, the other mammals have an anterior commissure and hipocampal commissure. In humans, the different portions of the corps callosum are described on a median sagittal slice: rostrum, genu, body, isthmus, splenium. Klingler method allows to dissect fibers of each of these portions and their relationship with the corona radiata and optic radiations. These latter are separated from the ventricular ependyme by callosal radiations. Finally, each part of the corpus callosum participates in lateral ventricle wall formation.

Animals↗
PubMed1998

[Arterial and venous vascularization of the corpus callosum].

Blood supply of the corpus callosum is assured by two arterial systems, the carotid system mainly and the vertebrobasilar system accessorily. The carotid system intervenes via the pericallosal artery, portion of the anterior cerebral artery distal to the anterior communicating artery. This pericallosal artery can be bihemispheric in 4 to 12% of the cases or azygos in 0.26% of cases. In 20 to 80% of cases, the median callosal artery arises from the communicating artery. The vertebrobasilar system intervenes in splenium vascularization by its terminal branches. These two carotid and vertebrobasilar systems give rise to perforating arteries that assure intrinsic vascularization of the corpus callosum creating a system of regular vascular stitches around the fibers of the corpus callosum. The venous drainage of the corpus callosum is essentially via callosal veins and callosocingulate veins towards the deep venous system of the brain.

Animals↗
PubMed1998

[Surgical approaches to the corpus callosum].

There are no dedicated approaches to the corps callosum itself. The different approaches, subcallosal, supracallosal and posterior to the splenium are usually used to reach neighboring structures such as third ventricle or pericallosal arteries. MRI is the best guideline to reach a specific position in the corps callosum and must imperatively contribute to the choice of the type of approach. During the procedure, it is necessary to take great care to protect the vessels, arteries and veins especially, to avoid ischemic damage which is the main complication of these approaches.

Cerebrovascular Circulation↗
PubMed1997

A new concept in Dorello's canal microanatomy: the petroclival venous confluence.

The so-called Dorello's canal was studied in 32 specimens (16 human cadaver heads) injected with colored latex and fixed in formalin (28 specimens) or studied with microscopic and ultrastructural methods (four specimens). To avoid the differences usually encountered in the description of this area, the authors preferred to consider a larger space that they have named the petroclival venous confluence (PVC). It was located between two dural layers: inner (or cerebral) and outer (or osteoperiosteal). The PVC was quadrangular on transverse section. The posterior petroclinoid fold and the axial plane below the dural foramen of the abducent nerve (sixth cranial nerve) limited the PVC at the top and bottom, respectively. Its anteroinferior limit was the posterosuperior aspect of the upper clivus and outer layer of the dura mater. Its anterior limit was the vertical plane containing the posterior petroclinoid fold, and its posterior limit was the inner layer of the dura. The PVC was limited laterally by the medial aspect of the petrous bone apex and medially by the virtual sagittal plane extending the medial limit of the inferior petrosal sinus upward. The PVC was a venous space bordered by endothelium and continuous with the cavernous sinus, the basal sinus of the clivus, and the inferior petrosal sinus. There were trabeculations between the two dural layers. The petrosphenoidal ligament of Gruber may be regarded as a larger trabeculation, and it divided the PVC into a superior and an inferior compartment. The abducent nerve generally ran through the inferior compartment, where it was fixed to the surrounding dura mater. This nerve was only separated from venous blood by a meningeal sheath of varying thinness lined with endothelium. The clinical implications of these findings are discussed.

Abducens Nerve↗