Search PubMed⌕ Search

Biomedical subjects

H Sick

Publications and source records attributed to H Sick.

At least 37 records · Page 2Linked to original sources

Exogenous and endogenous nitrogen flow rates and level of protein hydrolysis in the human jejunum after [15N]milk and [15N]yoghurt ingestion.

Milk and yoghurt proteins were 15N-labelled in order to measure the flow rate of exogenous N during digestion in the human intestine. After fasting overnight, sixteen healthy volunteers, each with a naso-jejunal tube, ingested either [15N]milk (n 7) or [15N]yoghurt (n 9). Jejunal samples were collected every 20 min for 4 h. A significant stimulation of endogenous N secretion was observed during the 20-60 min period after yoghurt ingestion and the 20-40 min period after milk ingestion. The endogenous N flows over a 4 h period did not differ between the groups (44.3(SEM 6.5) mmol for milk and 63.5(SEM 5.9) mmol for yoghurt). The flow rates of exogenous N indicated a delayed gastric emptying of the yoghurt N compared with N from milk. The jejunal non-protein N (NPN) flow rate increased significantly after milk and yoghurt ingestion due to an increase in the exogenous NPN flow rate. The NPN fraction of exogenous N ranged between 40 and 80%. The net gastro-jejunal absorption of exogenous N did not differ significantly between milk (56.7(SEM 8.5)%) and yoghurt (50.9(SEM 7)%). The high level of exogenous N hydrolysis is in accordance with the good digestibility of milk products. Fermentation modifies only the gastric emptying rate of N and does not affect the level of diet hydrolysis, the endogenous N stimulation or the digestibility rate.

Adult↗

15N-labeled immunoglobulins from bovine colostrum are partially resistant to digestion in human intestine.

To evaluate true ileal digestibility of bovine immunoglobulins, seven healthy human adults ingested a 15N-labeled preparation of an immunoglobulin concentrate. After fasting overnight, subjects drank 400 mL of immunoglobulin concentrate (77 mmol), and ileal effluents were collected for 8 h at 20-min intervals using a naso-intestinal intubation technique. In addition to osmolality and pH, the concentrations of exogenous and endogenous nitrogen and ions (Na+, K+, Cl-, Ca2+, Mg2+) in the effluents were measured. Bovine immunoglobulin concentrations (IgG, IgM, IgA) were estimated by a radial immunodiffusion technique. The mean flow rate of the liquid phase was 22.3 +/- 6.1 mL/20 min and did not vary significantly during the collection period. No change was observed for osmolality, pH or Na+, K+ and Cl- concentrations. Two hours after meal ingestion, Ca2+ and Mg2+ concentrations increased significantly (P < 0.05). The recoveries of nitrogen of ingested IgG and IgM still immunologically active were 19 +/- 3% and 19 +/- 4%, respectively. No IgA was detected in the ileum. Mean digestibility of the exogenous nitrogen fraction was 79 +/- 3%. In comparison to literature data, which show that other milk proteins have ileal digestibilities of > 90%, our results demonstrate a lower ileal digestibility of bovine immunoglobulins in humans.

Adult↗

[A cephalometric study of the pterygoid process during growth].

This study consists in a three dimensional cephalometric approach of the pterygoid process and its relationships with the neighbouring cranio-facial structures, using biostatistical analysis. The authors present the results of this method comparing the variations of the pterygoid process in relation to the variations of the basi-cranium and the face.

Adult↗

[Imaging of connective tissue formations of the sub-umbilical anterior abdominal wall].

New high resolution imaging modalities (CT and MRI) can distinguish between bladder and anterior abdominal wall pelvic connective tissue. The main structure is the umbilicovesical fascia located anterior to the peritoneum and posterior to the transversalis fascia. This layer divides the space between an anterior prevesical space and a posterior perivesical space. An understanding of these spaces facilitates the clinical identification and topography of pelvic the fluid collections.

Abdominal Muscles↗

Gastric emptying regulates the kinetics of nitrogen absorption from 15N-labeled milk and 15N-labeled yogurt in miniature pigs.

Thirty-six miniature pigs divided into two groups of 18 animals were fed 15N-labeled milk or yogurt. Polyethylene glycol 4000 was added to the diets as a non-absorbable marker of the liquid phase. Animals were slaughtered 1, 2, 4, 8 and 12 h after meal ingestion, and the gastrointestinal tract was removed and divided into 10 parts. Polyethylene glycol, total nitrogen and 15N enrichment were measured in the digesta. Both the intestinal delivery of the liquid phase and the nitrogenous fraction of the chyme were delayed more in pigs fed yogurt than in pigs fed milk. No stimulatory effect of diet ingestion on endogenous nitrogen secretion was found. Both milk proteins and yogurt proteins were highly digestible: 93% of the exogenous nitrogen disappeared 12 h after feeding. The kinetics of exogenous nitrogen delivery into the intestine was correlated (r = 0.999 for milk and r = 0.974 for yogurt) with that of exogenous nitrogen absorption. These results suggest that milk proteins are rapidly absorbed after they reach the intestine. Gastric emptying is a major factor controlling the kinetics of milk nitrogen absorption.

Animals↗

True exogenous and endogenous nitrogen fractions in the human jejunum after ingestion of small amounts of 15N-labeled casein.

The purpose of this work was to determine exogenous and endogenous contributions to the overall nitrogen flux in the upper jejunum in humans. After the ingestion of water or 8 g of [15N]casein, the behavior of gastro-jejunal nitrogen and electrolyte (Na+, K+, Cl-) movements were studied in seven volunteers using the "slow marker" perfusion technique. The jejunal flow-rate of the chyme peaked during 0-20 min and 20-40 min periods following water and casein ingestion, respectively. Osmolarity, Cl- and Na+ concentrations decreased significantly (P < 0.05) during the first 20 min following meal ingestion and returned to the basal levels in the 20-60 min period. The gastric half-emptying times (min) of the liquid phase differed significantly (P < 0.05) for water (7.9 +/- 0.4) and casein (21.4 +/- 9.1). The basal flow rate of endogenous nitrogen was 9 +/- 3.3 mmol/h in the jejunum. After casein ingestion, the total nitrogen content reached maximum values in the 20-40 min period and then progressively returned to the initial level. The gastro-jejunal casein absorption was 58% and the remaining amount of casein in the jejunum was degraded more than 80% to alcohol-soluble compounds. After the ingestion of a low amount of casein no significant increase in the endogenous nitrogen fraction was observed. The 15N-dilution technique is an appropriate method in humans for the direct measurement of endogenous and exogenous contributions to the intestinal nitrogen fraction.

Adult↗

High resolution MRI of the normal finger at 0.1 T: anatomic correlations.

MR images of the fingers are obtained in a 128 x 128 or 256 x 256 matrix format using a prototype of a mini imager dedicated to the hand. The vertical field of 0.1 T is provided by an electro-magnet with an air gap of 15 cm equipped with a single solenoidal coil. No Faraday cage is used. The maximum in plane pixel resolution of 100 mu is obtained for a field of view of 2.5 cm with a slice thickness of 2 mm. The identification of fine structures of the finger is demonstrated by the anatomical and histological correlations. This type of imager which is adapted to very limited field of views demonstrate that high resolution MRI of limb extremities can be achieved at 0.1 T.

Fingers↗

[The posterior intervertebral spaces of the craniovertebral joint].

Closing of the posterior intervertebral spaces of the craniovertebral joint is not performed by the classical posterior atlanto-occipital and atlantoaxial membranes. In the atlanto-occipital space, the connective laminae come from the occipital periosteum and from the anterior fascia of the rectus capitis posterior minor muscle, and pass round the anterior side of the posterior arch of the atlas to reach the spinal dura mater. In the atlantoaxial space, the anterior fasciae of the rectus capitis posterior major muscle and of the inferior oblique muscle, as well as the periosteum of the posterior arch of the atlas, extend to reach the spinal dura mater. Thus, the epidural space is sealed posteriorly by the connective laminae of the atlantoaxial space, and lets above a superior recessus containing the ganglia of the spinal nerves C1 and C2 and in which the vertebral artery transits.

Adult↗

Cow's milk protein allergy--results of skin-prick test with purified milk proteins.

The diagnosis of milk-protein allergies is difficult. Therefore, the main cow's milk proteins (alpha-lactalbumin, beta-lactoglobulin A + B, alpha s-casein, beta-casein, kappa-casein), purified to the highest available standards, were used for differential diagnosis of allergic individuals by applying skin-prick test. In the case of adults with uncertain medical history, milk proteins rarely caused skin reactions, while distinct skin reactions were observed in 11 of 13 children with strongly suspected milk-protein allergy. In the presented study alpha-lactalbumin and beta-lactoglobulin B were the main allergens, because skin reactions to these proteins were provoked with highest prevalence and intensity. Intensity and prevalence of reactions to alpha- and kappa-casein were significantly less. In two cases skin reactions to alpha-lactalbumin were observed exclusively.

Adolescent↗

[Vascularization of the adipose body of the cheek].

The vascular pedicles of Bichat's fat pad are numerous. The most important artery is the buccal artery, branch of the maxillary artery, which supplies the principal part and the six extensions of the buccal fat pad. Not only many other branches of the maxillary artery, but also branches of the facial artery and of the superficial temporal artery send thin vessels to cross the capsule and supply Bichat's fat pad, body and extensions, from periphery to center. The microcirculation of Bichat's fat pad shows a network almost similar with those of the other zones of white adipose tissue, but the capillary meshes are smaller and more tightened, the capillaries have a bigger diameter and several "basket-like" structures are to be find beneath the capsule.

Adipose Tissue↗

[Extra-osseous and intra-osseous microvascularization of the sternum of the child].

The microvascularization of the sternum of the child has been studied by a method of India ink injection and by histology. Extra-osseous vasculature includes vascular pedicles and sternal vascular networks. Vascular anterior and posterior pedicles issue from internal mammary vessels. Sternal anterior and posterior networks are disposed on the faces of the sternum and are divided in a superficial one and a deep one; both are included in the perichondrium. In newborns and in young infants, vascular structures looking like baskets are affixed to the deep sternal network. It is unlikely that they intervene in the constitution of the adult pattern of the sternal vasculature. The early complete development of sternal networks contrasts with the existence of evolutive characteristics of the intra-osseous vasculature. Intra-osseous vasculature includes the cartilage canal vessels and the vessels of the ossification centers. Cartilage canals are provided with an axial artery, issued from the deep sternal network, which produces short capillaries which continue in peripheral sinuses. Cartilage canals permit the penetration of perichondral tissue deep in the cartilage of the developing sternum, allowing the formation of the ossification center. The ossification center is vascularized by centrifugal arteries, issued from the cartilage canal artery, and disposed in a radiant pattern. They continue, through a conical progressive dilatation, into a sinusoid network, which presents a convergent disposition towards the center of the ossification point. Vascular events precede ossification. Hematopoietic development is consecutive to the vascular events too. The slenderness of vascular pedicles contrasts in neonates with the wide development of the sinusoid network. Adipose tissue is rare in the bone marrow sternum of the child. Secondary evolution of the ossification center vasculature permits its connections with the deep sternal vascular network, with adjacent cartilage canals, and with adjacent ossification centers. Progressively, the number and the importance of the peripheral pedicles of the ossification centers increase. Thus, a multiple and centripetal vascular provision takes the place of the initial, unique, centrifugal one. These modifications correspond to the transition from the vascular pattern of an expanding structure (the ossification center) to the one which is adapted to the full expression of its hematopoietic function.

Adolescent↗

[Bichat's fat pad: anatomy and imaging].

Topographic anatomy of the different parts of the corpus adiposum buccae is analyzed by coronal, transverse and sagittal sections. These sections are compared with those realized in the same planes by tomodensitometry and magnetic resonance. This comparison allows a better knowledge of the structures shown by imaging in the superficial and deep facial regions.

Adipose Tissue↗

[The buccal adipose body (Bichat's fat-pad). Morphological study].

Bichat's fat-pad was examined using dissections of newborns and adults, and histological sections of embryos and fetuses. A main part or body with six extensions (masseteric, superficial temporal, deep temporal, pterygomandibular, sphenopalatine and inferior orbital) can be recognized.

Adipose Tissue↗

[Microvascularization of the sternum in children].

46 sternums originating from 1-day- to 17-year-old children were injected with India ink and transparified. The intraosteal and medullary vasculature is described at different stages, as well as cartilage canals, vessels of the isolated ossification center, vessels of the ossification center connected with peripheral vascular structures or neighboring cartilage canals, and finally the transition to the adult pattern. With age, the centrifugal vascular distribution develops to a centripetal pattern.

Adolescent↗

Anatomy and computed tomography of the normal lumbosacral plexus.

The main nerves of the pelvis and lower limbs arise from the lumbar and sacral plexuses. These nerves can be affected by any of a large number of pathologic processes that occur in the paravertebral and pelvic regions. Understanding of the neurological findings related to paravertebral and pelvic pathology needs complete and accurate knowledge of the anatomy of these regions. The axial transverse sections of computed tomography give perfect visualisation of the anatomy of osseous, muscular, and vascular structures of the vertebral and paravertebral area and pelvic walls. Visualisation of the nerves in this regions is much more difficult, because direct demonstration of nervous structures by computed tomography is usually impossible. To be able to identify components of the lumbosacral plexus on axial CT sections the radiologist has to know the location of the nervous structures and the relationships of these structures to vascular, muscular and osseous structures which are easily demonstrated.

Humans↗

CT-anatomic correlations of the normal capsulo-ligamentous bands of the extrinsic joints of the thoracic spine.

Five anatomic specimens were studied in an attempt to visualize by high-resolution computed tomography (HRCT) the ligamentous bands of the costotransverse and costovertebral joints. HRCT-anatomic comparison is presented to relate the CT views to the anatomic structures. The authors demonstrate that axial, sagittal and, to a lesser extent, coronal HRCT views perfectly outline the ligamentous structures, although these are flattened, short, deep and free from calcium deposit. The method may be valuable in disease states such as ankylosing spondylitis.

Humans↗