Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Digitation junction”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources
PubMed1997

The annular tinted contact lens syndrome: corneal topographic analysis of ring-shaped irregular astigmatism caused by annular tinted contact lenses.

PURPOSE: Irregular corneal astigmatism has been reported in association with annular tinted hydrogel contact lenses. We report the abnormal videokeratographic findings of five patients wearing annular tinted contact lenses, who presented with bilateral blurred vision and revealed a loss of best corrected visual acuity. METHODS/RESULTS: The corneal topographic analysis revealed a previously unreported distinct ring-shaped pattern of irregular astigmatism. The topographic circular band of irregular astigmatism was further characterized by concentric areas of relative steepening, flattening, and steepening with a diameter of approximately 4 mm. This pattern suggests that forces acting at the junctional zone between the tinted area and the clear pupillary area are inducing structural abnormalities of the corneal surface. At the time of presentation, the mean surface regularity index (SRI) was 2.06 (range: 0.61-5.88). The topography and best-corrected visual acuity returned to normal within days of discontinuing annular tinted lens use, and the mean SRI decreased to 0.44 (range: 0.21-1.16). Digital imaging of lenses obtained from our patients and of identical control lenses was performed. A masked analysis suggested that the study lenses contain greater amounts of pigment compared to the control lenses. CONCLUSIONS: We present ten characteristic signs and symptoms of this condition, which we have named "the annular tinted contact lens syndrome." Corneal topographic analysis is a powerful tool for detecting specific reversible irregularities of the corneal surface associated with the use of annular tinted contact lenses.

Adolescent↗
PubMed1997

Cortical bone distribution in the femoral neck of hominoids: implications for the locomotion of Australopithecus afarensis.

Contiguous high resolution computed tomography images were obtained at a 1.5 mm slice thickness perpendicular to the neck axis from the base of the femoral head to the trochanteric line in a sample of 10 specimens each of Homo sapiens, Pan troglodytes, and Gorilla gorilla, plus five specimens of Pan paniscus. Superior, inferior, anterior, and posterior cortical thicknesses were automatically measured directly from these digital images. Throughout the femoral neck H. sapiens displays thin superior cortical bone and inferior cortical bone that thickens distally. In marked contrast, cortical bone in the femoral neck of African apes is more uniformly thick in all directions, with even greater thickening of the superior cortical bone distally. Because the femoral neck acts as a cantilevered beam, its anchorage at the neck-shaft junction is subjected to the highest bending stresses and is the most biomechanically relevant region to inspect for response to strain. As evinced by A.L. 128-1, A.L. 211-1 and MAK-VP-1/1, Australopithecus afarensis is indistinguishable from H. sapiens, but markedly different from African apes in cortical bone distribution at the femoral neck-shaft junction. Cortical distribution in the African ape indicates much greater variation in loading conditions consistent with their more varied locomotor repertoire. Cortical distribution in hominids is a response to the more stereotypic loading pattern imposed by habitual bipedality, and thin superior cortex in A. afarensis confirms the absence of a significant arboreal component in its locomotor repertoire.

Animals↗
PubMed1996

Does surgical repair of a rectocele improve rectal emptying?

PURPOSE: This study was undertaken to assess results of surgical repair of rectocele and to identify possible determinants of outcome from patient's history and preoperative defecography. Another aim was to evaluate how surgery affects rectal evacuation. METHOD: Thirty-four women with constipation and rectal emptying difficulties underwent surgery with a transanal technique. A preoperative defecography was performed in each patient. They were followed up after a median of 10 (range, 2-60) months with a questionnaire (n = 34) and a defecography (n = 31). Computer-based image analysis of defecographies was used to evaluate rectal evacuation. RESULTS: In 27 patients (79 percent), the result of surgery was good with subjectively improved emptying. The need for vaginal or perineal digitation preoperatively was related to a good result (P < 0.05), whereas a previous hysterectomy (P < 0.01) and a large rectal area on defecography (P < 0.01) related to a poor result. Preoperative use of enemas, motor stimulants, or several types of laxatives also related to a poor outcome (P < 0.05). Surgical treatment resulted in reduction of the rectocele (P < 0.001), an elevated position of the anorectal junction (P < 0.05), and improved rectal evacuation on defecographies (P < 0.001). CONCLUSIONS: Surgical repair reduces the size of the rectocele and improves rectal emptying. These changes are accompanied by a symptomatic improvement in the majority of patients. Preoperative patient data and defecography may help in selecting patients for surgery.

Adult↗
PubMed2004

Three-dimensional computer-assisted reconstruction of ductal plate in the rat embryo (Carnegie stages 19-23).

In bile duct morphogenesis it has been established that the extrahepatic bile ducts in human originate from hepatic diverticulum while intrahepatic bile ducts arise from the ductal plate (DP), a network of primitive biliary epithelium that develops in the periportal connective tissue. The aim of this work was to reconstruct in rat embryos, stages 19-23, the three-dimensional (3D) distribution of the DP by means of a computer-assisted method. Six specimens, stages 19-23, fixed, dehydrated and paraffin-embedded, were submitted to serial histological sections and stained by hematoxylin-eosin and Heidenhain techniques. The images were directly digitalized with a CCD camera. The serial views were aligned anatomically by software and the data were analyzed following segmentation and thresholding. At stage 19, the DP was not yet organized. The periportal mesoderm (M) was gaining ground with some cords of cubic cells evoking primitive ductal cells. At stage 20, a row of ductal cubic cells went around the transverse portal sinus at the junction between M and liver cells. At stage 21, the DP developed at the periphery of periportal connective tissue and appeared in direct continuity with the hepatic duct (HDu). Four evaginations emerged from the DP and were growing up in the hepatic parenchyma. At stage 23, the DP appeared as a large network in continuity with the HDu located at the periphery of periportal M and presenting several evaginations radiating in the liver parenchyma. This work in the rat embryo permits the clear visualization of the development of the junctional zone in the hepatic hilum. Three phenomena are observed: (1) proximal left and right hepatic ducts and their segmental branches are derived from DP and not from the HDu; (2) the extrahepatic biliary system is in contact with the developing hilar ducts; (3) ductal maturation begins at the hilum and proceeds centrifugally. These observations are of great relevance in explaining pathological changes appearing at the hepatic hilum of neonates: hepatic polycystic disease, intrahepatic bile duct agenesis or atresia, and cyst of the extrahepatic bile duct.

Animals↗
PubMed1989

[Usefulness of dual-energy digital radiography in detecting atlas and axis].

Cranial dual-energy digital radiography was applied to three patients. The anatomy of the atlas and axis was clearly recognized without utilizing the open-mouth view. We consider it a very effective technique when applied to the patient who experiences difficulty in opening the mouth, like severe traumatic or infantile patients. In addition, it is a useful examination for patients with suspected anomalies of cranio-vertebral junction.

Axis, Cervical Vertebra↗
PubMed2006

Ventriculo-aortic junction in human root. A geometric approach.

With advances in tissue engineering and improvement of surgical techniques, stentless biological valves and valve-sparing procedures have become alternatives to traditional aortic valve replacement with stented bioprostheses or mechanical valves. New surgical techniques preserve the advantages of native valves but require better understanding of the anatomical structure of the aortic root. Silicone rubber was injected in fresh aortic roots of nine human cadavers under the physiological closing pressure of 80 mmHg. The casts reproduced every detail of the aortic root anatomy and were used to digitize 27 leaflet attachment lines (LALs) of the aortic valves. LALs were normalized and described with a mathematical model. LALs were found to follow a pattern with the right coronary being the largest followed by the non-coronary and then the left coronary. During diastole, the aortic valve LAL can be described by an intersection between a created tube and an extruded parabolic surface. This geometrical definition of the LAL during end diastole gives a better understanding of the aortic root anatomy and could be useful for heart valve design and improvement of aortic valve reconstruction technique.

Adult↗
PubMed2002

Temperature change within gutta-percha induced by the System-B Heat Source.

AIM: This study evaluated the temperature change within gutta-percha during the vertical compaction technique performed with a System-B Heat Source. METHODOLOGY: Extracted human teeth were prepared and divided in two equal groups depending on the apex diameter (group 1: 0.20-0.25 mm and group 2: 0.30-0.35 mm). Teeth were root treated with a combination of step-back and coronal flaring instrumentation using Gates Glidden burs and hand stainless steel K- and H-files. Two thermocouples were connected to the outer surface of the root: the first one was placed 2 mm apically from cement-enamel junction (CEJ) (point C); and the second one 1.5 mm from the apex (point A). The instrumented canals were filled with size F gutta-percha cones. All teeth were then immersed in a thermostatic bath at a constant temperature of 37 degrees C and warm vertical compaction was performed using a System-B Heat Source. delta T values were recorded by means of a digital thermometer connected to the thermocouples. RESULTS: Increments of temperature (delta T) recorded in point A revealed a mean value of 0.5 +/- 0.5 degree C for group 1 and 0.9 +/- 1.1 degrees C for group 2; delta T values recorded at point C gave a mean value of 4.1 +/- 1.7 degrees C for group 1 and 3.9 +/- 1.81 degrees C in group 2. No statistical difference was found between the groups, whilst a difference was present between the measurements at points A and C (P < 0.01). CONCLUSIONS: The use of the System-B Heat Source on root canals maintained at a constant body temperature by a thermostatic bath revealed that the increase of temperature of the gutta-percha at the apical third of the canal was negligible and that the compaction of the mass of the gutta-percha close to the apex was performed at body temperature. Minor changes in temperature of the outer surface of the root canals occurred, suggesting no danger for the periradicular tissues.

Analysis of Variance↗
PubMed1982

[Sensory receptors in flexors and extensors of the fingers during human prenatal ontogenesis and in children under 3].

The superficial human digital flexor and extensor are rich in terminal sensitive apparatuses and they present peculiar reflexogenic zones. There is not any essential difference between these muscle-antagonists according to the topography of the receptors, but functionally different muscle areas (both in the superficial digital flexor and in the digital extensor) are not equally provided with the receptory apparatuses. In the course of development, the number of sensitive terminals in the proximal and distal portions of the muscles is increasing. An absolute number of the receptors is much greater in the digital superficial flexor than in the digital extensor, nevertheless, this difference per 1 g of mass disappears; that can be evidently connected with complexity and differencity of movements which the upper extremities perform.

Child, Preschool↗
PubMed1991

Preliminary evidence for noradrenaline and ATP as neurotransmitters in the porcine isolated palmar common digital artery.

Sympathetic neurotransmission in porcine isolated palmar common digital artery involves the release of noradrenaline and ATP which produce constrictor responses via alpha 1-adrenoceptor and P2x receptors, respectively. Responses to short trains of pulses (e.g. 4 pulses at 2Hz) are almost entirely attributable to ATP, while those to longer trains of pulses appear to involve both transmitters. Unlike the corresponding blood vessel in man (Stevens and Mould, 1985) no evidence for "innervated" post-junctional alpha 2-adrenoceptors was found.

Adenosine Triphosphate↗
PubMed1988

Scanning electron microscopy of skin surface and the internal structure of corneocyte in normal human skin. An application of the osmium-dimethyl sulfoxide-osmium method.

A horny layer of normal human skin prepared according to the newly developed osmium-dimethyl sulfoxide-osmium method was examined using scanning electron microscopy. On the skin surface, cytomembranes of the uppermost corneocytes frequently had unilateral, very slightly flat-elevated, zonal areas along the junctions between the corneocytes. The uppermost corneocytes peeled off along the junctions, leaving the remnants of their cell bodies in the junctional areas. In the cracked surface, cytomembranes of the corneocytes protruded from the plane of their cytoplasmic surface. In the lateral junction between the corneocytes, the cytomembranes of the corneocytes were in tight contact with each other, while occasionally the marginal bands had become detached from the cytomembranes. In the vertical connection, cleavages formed between the cytomembranes of the corneocytes. There were thick woollen thread-like structures about 10-30 nm thick in the cytoplasm of the corneocytes. They formed fine irregular meshworks, with their tips projecting digitally: Transmission electron microscopy revealed these structures as most likely being keratin bundles transformed during processing.

Cell Membrane↗
PubMed2005

Effects of pulsed Nd:YAG laser on microleakage of composite restorations in class V cavities.

OBJECTIVE: The purpose of this study was to evaluate the effects of pulsed Nd:YAG laser on decrease of dentinal microleakage beneath the restoration. METHODS: Thirty-two sound extracted premolar teeth were subjected to two standardized, V-shaped, class V cavity preparations on both buccal and lingual surfaces. Cavities were located at 1-2 mm below the cemento-enamel junction (CEJ) line. The teeth were divided into two groups of experimental and control in an random manner. Both 20 and 15 mJ/pulse laser energies were tested. Etching, bonding, and filling were performed using Tetric ceram composite material. All samples were thermocycled for 1000 cycles, followed by an immersing period of 1 week in 2% basic fuchsin solution. Specimens were then sliced longitudinally and evaluated under a digital scanner for the extent of dye penetration. RESULTS: Our results indicated that the level of microleakage of laser-treated cavities was significantly less than that of untreated cavities (p < 0.05) for 20 mJ/pulse laser energy. No significant decrease in microleakage level was observed for the 15 mJ/pulse laser energy. CONCLUSION: The short pulsed Nd:YAG laser with the energy of 20 mJ/pulse and aforementioned features appeared to be able to reduce microleakage toward pulp.

Composite Resins↗
PubMedDate not supplied

Pneumomediastinum revisited.

Pneumomediastinum may result from a variety of causes that may be either intrathoracic (eg, narrowed or plugged airway, straining against a closed glottis, blunt chest trauma, alveolar rupture) or extrathoracic (eg, sinus fracture, iatrogenic manipulation in dental extraction, perforation of a hollow viscus [corrected]. The radiographic signs of pneumomediastinum depend on the depiction of normal anatomic structures that are outlined by the air as it leaves the mediastinum. These signs include the thymic sail sign, "ring around the artery" sign, tubular artery sign, double bronchial wall sign, continuous diaphragm sign, and extrapleural sign. In distal esophageal rupture, air may migrate from the mediastinum into the pulmonary ligament. Pneumomediastinum may be difficult to differentiate from medial pneumothorax and pneumopericardium. Occasionally, normal anatomic structures (eg, major fissure, anterior junction line) may simulate air within the mediastinum. Iatrogenic entities that may simulate pneumomediastinum include helium in the balloon of an intraaortic assist device. In addition, pneumomediastinum may be simulated by the Mach band effect, which manifests as a region of lucency adjacent to structures with convex borders. The absence of an opaque line, which is typically seen in pneumomediastinum, can aid in differentiation. Computed tomographic (CT) digital radiography and conventional CT can also be helpful in establishing or confirming the diagnosis.

Adolescent↗
PubMed2000

ROCK mediates thrombin's endothelial barrier dysfunction.

Thrombin-induced endothelial monolayer hyperpermeability is thought to result from increased F-actin stress fiber-related contractile tension, a process regulated by the small GTP-binding protein Rho. We tested whether this process was dependent on the Rho-associated protein kinase, ROCK, using a specific ROCK inhibitor, Y-27632. The effects of Y-27632 on thrombin-induced myosin light chain phosphorylation (MLCP) and tyrosine phosphorylation of p125 focal adhesion kinase (p125(FAK)) and paxillin were measured by Western blotting. F-actin organization and content were analyzed by digital imaging, and endothelial monolayer permeability was measured in bovine pulmonary artery endothelial cell (EC) monolayers using a size-selective permeability assay. Y-27632 enhanced EC monolayer barrier function due to a decline in small-pore number that was associated with increased EC surface area, reduced F-actin content, and reorganization of F-actin to beta-catenin-containing cell-cell adherens junctions. Although Y-27632 prevented thrombin-induced MLCP, stress fiber formation, and the increased phosphotyrosine content of paxillin and p125(FAK), it attenuated but did not prevent the thrombin-induced formation of large paracellular holes. These data indicate that thrombin-induced stress fiber formation is ROCK dependent. In contrast, thrombin-induced paracellular hole formation occurs in a ROCK-independent manner, whereas thrombin-induced monolayer hyperpermeability appears to be partially ROCK dependent.

Actins↗
PubMed2003

Supplemental role of the Ames mutation assay and gap junction intercellular communication in studies of possible carcinogenic compounds from diesel exhaust particles.

This study presents a new strategy for the carcinogenic evaluation of complex chemical mixtures based on genotoxic and nongenotoxic assays. We studied the ability of organic extracts of diesel exhaust particles (DEP) to induce point mutations in five different Salmonella typhimurium strains (Ames test) and to inhibit gap junction intercellular communication (GJIC) in rat liver epithelial cell lines. A crude extract of DEP was prepared by extraction with dichloromethane (DCM), and fractionated according to polarity into five fractions: aliphatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), nitro-PAH, dinitro-PAH, and polar compounds. Statistical experimental design, multivariate data analysis, and modeling were used to quantify the mutagenicity of individual and combined DEP fractions in the Ames assay. Quantitative determination of GJIC was carried out using a recently described combination of scrape loading and digital image analysis. Both assays responded to the DEP extract, but the responses were due to different fractions. The nitro-PAH fraction showed the strongest mutagenic potential, followed by the dinitro-PAH fraction. The effect on GJIC was due to the fraction containing the polar components, followed by the dinitro-PAH fraction. The extract was found to induce both basepair substitutions and frameshift mutations, through activation by bacterial nitroreductases. Hyperphosphorylation of connexin43, the major connexin in the epithelial cell lines, was less evident for DEP extract than for other communication inhibitors such as phorbol esters and growth factors, and consequently inhibitors of the protein kinase C (PKC) and mitogen-activated protein (MAP) kinase pathway were unable to counteract the inhibition by DEP extract. Since the Ames test is a well accepted method to screen for substances with genotoxic activity while inhibition of GJIC is associated with effect of tumor promoters and nongenotoxic carcinogens, it is not surprising but encouraging and interesting that the present data indicate that the two endpoints supplement each other as screening tests and in the evaluation of hazardous compounds in complex mixtures.

Animals↗
PubMed2000

Repair of muscle and musculotendinous junction injuries with an autogenous fascial patch.

We have used an autogenous fascia lata patch to repair muscle and musculotendinous junction injuries affecting 99 individual muscles in 23 patients with multiple incised wounds to the upper limbs. All patients were followed up for at least 2 years. Two patients with severe dystrophic changes following nerve injuries were excluded from the final analysis. Satisfactory grip strength was restored 6 months following the repair in 19 of the 21 patients we evaluated. Complete active and passive range of wrist and digital motion was seen in 18 of these 21 patients. Tightness of the flexor pollicis longus was seen in 2 patients, one of whom had a deformity of the interphalangeal joint of the thumb that was passively stretched and subsequently reduced. Scar adhesions were noted in 4 other patients, but this did not affect wrist or finger motion, except in one. The autogenous fascial patch repair technique provides strong and good apposition of muscle fibres simply by distributing the force and tension over a large area of the muscle, thereby allowing early mobilization and functional restoration of the extremity.

Arm Injuries↗
PubMed1996

Paracrine mediation of calcium signaling in human SK-N-MCIXC neuroepithelioma cells.

Paracrine-mediated Ca2+ signaling in SK-N-MCIXC neuroepithelioma cells was evaluated by means of two experimental paradigms. In the first, single SK-N-MCIXC cells were microinjected with inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] and cytoplasmic Ca2+ was monitored by fura 2 digital-imaging microfluorometry. In response to Ins(1,4,5)P3 or CaCl2, but not inositol 1,3,4-trisphosphate, an increase in cytoplasmic Ca2+ concentration ([Ca2+]i) was observed in injected cells and also in neighboring cells. The direction of intercellular propagation of Ca2+ signals was influenced by the presence of a flow in the extracellular medium and occurred in the absence of any detectable gap-junctional communication. The P2 purinoceptor antagonist suramin, but not antagonists of other phosphoinositide-linked receptors, blocked cell-to-cell Ca2+ signaling initiated by microinjections of Ins(1,4,5)P3. In the second paradigm, conditioned medium (CM) obtained from monolayers of SK-N-MCIXC cells elicited increases in [Ca2+]i when reapplied to cells on coverslips. The Ca(2+)-mobilizing activity of CM was reversibly antagonized by suramin and abolished by pretreatment with apyrase. The presence of nucleotide di- and triphosphates in CM was confirmed by high-performance liquid chromatography. We conclude that SK-N-MCIXC cells release nucleotides that then activate specific receptors on neighboring cells. A rise in [Ca2+]i in these cells, and subsequent additional release of nucleotides, serves to further the propagation of intercellular Ca2+ signals.

Biological Transport↗
PubMed1993

Effect of estrogen deficiency on IGF-I plasma levels: relationship with bone mineral density in perimenopausal women.

Bone tissue is a source of growth factors; among them, insulinlike growth factor I (IGF-I) is probably an important local regulator of bone formation. This study has been carried out in order to assess the effects of natural menopause on plasma concentrations of IGF-I in the first 6 years after the cessation of gonadal function independent of age. We also examined the relationship between plasma IGF-I levels and bone mineral density (BMD) measured at the lumbar spine (LS), at the ultradistal radius (UDR), and at the junction of the distal and middle thirds of the radius (MR). Sixty-seven healthy nonobese women, aged 45-55, were studied (premenopausal n = 21; postmenopausal n = 46, from 1 to 6 years since menopause). Plasma IGF-I levels were measured by RIA, after acid-ethanol extraction. BMD of the forearm was measured by dual-photon densitometer and BMD of the LS was assessed by quantitative digital radiography. Mean values of IGF-I plasma levels were significantly reduced in postmenopausal women compared to the premenopausal group. Menopausal duration did not influence IGF-I plasma levels in postmenopausal women. We also found a positive correlation between IGF-I levels and BMD measured at MR both in pre- and postmenopausal women, while a correlation with LS and UDR-BMD was found only in fertile subjects. The results show that IGF-I plasma levels decrease immediately after menopause, since significantly lower levels are reached in the first years. The correlations found between plasma IGF-I levels and BMD suggest a possible role of reduced IGF-I in bone loss at particular skeletal sites.

Aging↗
PubMed1997

Three-dimensional reconstruction of the human fetal philtrum.

The anatomy of the philtrum is incompletely understood because it is difficult to analyze three-dimensionally. Previous anatomic studies suggested that the philtral ridges are formed by the dermal insertion of the orbicularis oris muscle and musculis nasalis decussating across the midline, with the philtral dimple an area of few muscular insertions. This theory is inconsistent with the usual finding of a normal-appearing philtrum contralateral to the cleft in patients with unilateral cleft lip. Using a microcomputer and three-dimensional software, we have created a three-dimensional model of the philtrum from digitized images of sequential transverse histological sections from a third-trimester fetus. Our studies demonstrate that the philtral ridges are formed by thickened dermis and dermal appendages. The labial levators are the predominant muscles associated with the philtrum throughout its length; their fibers insert into the dermis lateral to the philtral ridges. Crossing muscle fibers of the orbicularis oris pars marginalis only appear below the vermilion-cutaneous junction, caudal to the philtral ridges.

Cleft Lip↗