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PubMed1994

[Imposing "calcium milk" lithiasis in giant hydronephrosis].

The authors report a quite unusual case of "milk of calcium renal Stone" in unilateral giant Hydronephrosis. Radiographic, sonographic, intravenous urographic and TC aspects are described and prominence il given to morphostructural information obtained through digital image techniques of pyeloureteral zone junction and of "milk of calcium renal Stone". The authors discuss the pathogenesis of the renal Stone type and emphasize the convenience of investigative acts to clear up the ethio-pathogenetic role of pyeloureteral infections.

Adult↗
PubMedDate not supplied

Digital epiluminescence microscopy in the evaluation of pigmented lesions: a brief review.

Epiluminescence microscopy (ELM) is the application of oil followed by compression by a transparent material and examination under tangential illumination with magnification. This technique reduces the reflected light from the irregular surface of the stratum corneum and makes the epidermis more transparent so that structures at the dermal epidermal junction and upper dermis may be visualized. Digital ELM is the capture of ELM images by a television camera attached to a computer. The ELM approach results in improved diagnostic accuracy for pigmented lesions in the order of 20%. Advantages of digital ELM over standard ELM are the ability to capture images in an almost endless array of colors and hues, permanence of recording without degradation over time, the ability to transmit information electronically over long distances, and the ability to enhance certain features through electronic manipulation. Among the potential applications of digital ELM are assistance in establishing the diagnosis of melanoma during screening, maintenance and retrieval of images in patients who are being followed clinically with pigmented lesions, and better understanding of clinical histopathologic correlations.

Diagnosis, Differential↗
PubMed2006

The effect of dexamethasone in the pathogenesis of ligature-induced periodontal disease in Wistar rats.

The aim of this study was to evaluate, in rats, the role of the systemic use of dexamethasone in the pathogenesis of induced alveolar bone loss. In 26 female Wistar rats, ligatures were placed around the second upper molars, and the contralateral ones served as intra-group controls. Two groups were formed. The test group received 0.5 mg/kg of dexamethasone subcutaneously every third day during thirty days. The control group received the same amount of saline solution. After thirty days, the animals were sacrificed and their maxillae were removed. Sodium hypochlorite was used to prepare the specimens, and the cementum-enamel junction was stained with 1% methylene blue. Morphometric analysis of the alveolar bone loss was performed with standardized digital photographs, and the distance between the cementum-enamel junction and the alveolar bone crest was measured with the software ImageTool 3.0. Intra-examiner calibration revealed a Pearson correlation coefficient of 0.99. Statistical analysis was performed by paired or independent samplet tests, as appropriate (alpha = 0.05). Dexamethasone increased the mean alveolar bone loss in ligature-induced periodontitis in relation to the control group (0.77 and 0.61 buccally, and 0.65 and 0.56 palatally, respectively). No significant differences were observed intergroups in the teeth without ligatures. In the animal model used here, the use of dexamethasone increased the progression of ligature-induced alveolar bone loss.

Alveolar Bone Loss↗
PubMed1997

Reproducibility of bone height measurements made on serial radiographs.

The objective of this study was to determine the reproducibility of alveolar bone height measurements made on digitized images of serial radiographs using 3 different alignment systems for taking serial radiographs: 1) XCP Rinn System, 2) XCP Rinn System modified to include an alignment pin, and 3) I/EGAD system (impression based-electronically guided alignment device). Eighty duplicate films taken 1 hour apart of randomly selected anterior or posterior sites for alignment systems 1 and 2 were taken on 40 subjects. Thirty-eight duplicate films were taken of posterior and anterior sites on 19 subjects with alignment system 3. Cemento-enamel junction alveolar crest measurements were made on digital images using the side-by-side technique. Image pairs of serial radiographs were dichotomized into well-matched and poorly matched groups based on subjective evaluation of the geometric likeness. Of those taken with system 1, 47% were well matched; with system 2, 62%; and with system 3, 98%. The measurement error of change in radiographic bone height, defined as twice the standard deviation of difference (mm), was determined. This varied between 1.03 mm for poorly matched radiographic pairs taken with alignment system 1 and 0.52 mm for all radiographic pairs taken with alignment system 3. These results can be used together with power calculations to select an alignment system for a particular study. For example, power calculations indicate that detecting a bone change of 0.5 mm using the I/EGAD system would require one-third of the subjects needed when using the XCP Rinn method.

Adult↗
PubMed2005

The long sitting screening test in elite cyclists.

Pelvic rotation during cycling is important because it influences aerodynamics, cycling efficiency and the occurrence of overuse injuries. The aim of this study was to determine whether or not pelvic position in long sitting influences pelvic position during cycling. An observational, cross sectional, within-subjects study design was used. Thirty elite international track and road cyclists participated as subjects and two measures were undertaken. In long sitting, a digital inclinometer was positioned on the lumbosacral junction to give a static measure in degrees of sacral inclination (SI) relative to the horizontal. During active cycling, video analysis of reflective surface markers over the anterior superior iliac spine and posterior superior iliac spine was used to give a measure in degrees of anterior pelvic rotation (APR), by the angle between these two landmarks and the horizontal. No significant linear relationship was found between the two testing positions (r = 0.23, p = 0.22).

Adolescent↗
PubMed1986

Flexor tendon lengthening by tenotomy at the musculotendinous junction.

The author presents his experience with an established technique of flexor tendon lengthening by tenotomy at the musculotendinous junction. This technique can be used for digital stiffness of forearm origin when active extension is possible on flexion of the wrist. There must not be adherence in the carpal tunnel or in the digital sheath, and active flexion must be preserved. It can also be used for digital stiffness in addition to other techniques. This kind of lengthening has some advantages: there are no sutures in the tendon itself, and it allows early reeducation in association with dynamic extension splinting. Active flexion is preserved immediately and there is good tendon healing. It is possible to lengthen selectively the superficial flexor or the deep flexor and in some cases both. Results are presented according to cause.

Adult↗
PubMed1986

What determines the latency and amplitude of stationary peaks in far-field recordings?

In 20 radial nerves from 10 healthy persons, a referential derivation from the tip of the first or second digit registered two biphasic stationary peaks, PI-NI and PII-NII, following stimulation of the nerve in the forearm. These two peaks occurred slightly before the arrival of the propagating impulse at the wrist and at the base of the digit, respectively. With stepwise reduction of stimulation from a maximal to a threshold intensity, the far-field potential decreased in amplitude linearly with the near-field potential recorded at the junction of the volume conductor. Abduction of the first digit or flexion of the second and third digits altered the waveform and, to a lesser degree, the latency of the far-field peaks. However, these changes appeared in an inconsistent manner, which we were unable to characterize. We conclude that in far-field recording a stationary peak results at the border of the adjoining volume conductors in proportion to the magnitude of the propagating axonal volley approaching the boundary.

Adult↗
PubMed2002

Use of chromametry and digital photography for objective measurement of skin color in clinically normal dogs.

OBJECTIVE: To evaluate whether skin erythema in clinically normal dogs can be quantified by use of chromametry and image analysis of digital photographs. ANIMALS: 9 German Shepherd Dogs and 10 mixed-breed dogs. PROCEDURE: Hair was clipped at 7 sites on the body. Skin erythema was evaluated at the axillary region, right and left lateral aspect of thorax, right and left loin area (ie, part of the back between the thorax and pelvis), right and left groin area (ie, the junctional region between the abdomen and thigh), metatarsal digital pad, and on the nose. Replicate measurements were done by use of chromametry and image analysis of digital photographs, using erythema values in accordance with the Committee International d'Eclairage (CIE)-Lab color system. RESULTS: Repeatability was high for both techniques. Within-dog variation was lower than between-dog variation. Between-dog variation was high for both groups of dogs. Interregional variation was significant in German Shepherd Dogs and mixed-breed dogs. Erythema values revealed symmetry between the right and left lateral aspects of the thorax and loin and groin areas. CONCLUSIONS AND CLINICAL RELEVANCE: Precise objective methods are available for skin erythema quantification. Chromametric and photographic erythema values had a high within-dog reproducibility. Between-dog variability was high for German Shepherd Dogs and mixed-breed dogs as was regional variation, indicating differences in color among dogs.

Animals↗
PubMed2002

Knockdown of connexin43-mediated regulation of the zone of polarizing activity in the developing chick limb leads to digit truncation.

In the developing chick wing, the use of antisense oligodeoxynucleotides to transiently knock down the expression of the gap junction protein, connexin43 (Cx43), results in limb patterning defects, including deletion of the anterior digits. To understand more about how such defects arise, the effects of transient Cx43 knockdown on the expression patterns of several genes known to play pivotal roles in limb formation were examined. Sonic hedgehog (Shh), which is normally expressed in the zone of polarizing activity (ZPA) and is required to maintain both the ZPA and the apical ectodermal ridge (AER), was found to be downregulated in treated limbs within 30 h. Bone morphogenetic protein-2 (Bmp-2), a gene downstream of Shh, was similarly downregulated. Fibroblast growth factor-8 expression, however, was unaltered 30 h after treatment but was greatly reduced at 48 h post-treatment, when the AER begins to regress. Expressions of Bmp-4 and Muscle segment homeobox-like gene (Msx-1) were not affected at any of the time points examined. Cx43 expression is therefore involved in some, but not all patterning cascades, and appears to play a role in the regulation of ZPA activity.

Animals↗
PubMed1989

Axonal guidance and the development of muscle fiber-specific innervation in Drosophila embryos.

The outgrowth of peripheral nerves and the development of muscle fiber-specific neuromuscular junctions were examined in Drosophila embryos using immunocytochemistry and computer-enhanced digital optical microscopy. We find that the pioneering of the peripheral nerves and the formation of the neuromuscular junctions occur through a precisely orchestrated sequence of stereotyped axonal trajectories, mediated by the selective growth cone choices of pioneer motoneurons. We have also examined the establishment of the embryonic muscle fibers and, using intracellular dye fills, have identified cells that are putative muscle pioneers. The muscle fibers of the bodywall have completed their morphogenesis prior to the initiation of synaptic contacts, and owing to the timing of neurite outgrowth from the CNS, synaptogenesis is synchronous at muscle fibers throughout the bodywall. At each muscle fiber the innervating axons make their initial contacts on a characteristic surface domain of the target cell's membrane. Through stereotyped growth cone-mediated trajectories the motoneurons actively establish the basic anatomical features of the mature neuromuscular junction, including the stereotyped, muscle fiber-specific branch anatomy. These events occur without significant process pruning or apparent synapse elimination. Our results suggest that the basic elements of the mature neuromuscular innervation, including the details of the ending trajectory on the target cell's surface, are formed by the precise navigation and presumed recognition by the motoneuron growth cones of muscle membrane surface features.

Animals↗
PubMed2000

Dosimetric evaluation of abutted fields using asymmetric collimators for treatment of head and neck.

PURPOSE: The objective of this study was to reevaluate the dose nonuniformity of abutted fields defined using asymmetric collimators and one isocenter for treatment of the head and neck region. METHODS AND MATERIALS: Bilateral parallel-opposed fields abutted to the anterior field at one isocenter were implemented in the treatment of head and neck. The effect of digital display tolerance can produce dose nonuniformity at the junction of the abutted fields. The amount of dose nonuniformity was quantified using both mathematical summation of dose profiles and by direct measurement of doses at the junction of the two abutted fields. The dose nonuniformity was obtained by irradiating the superior part of a film using bilateral parallel-opposed fields and the inferior part by an anterior field with a gap or an overlap. Dose profiles were taken at the depth of maximum dose for the anterior field across the abutted fields. The dose nonuniformity was determined for the case where the asymmetric jaw was set at -2 mm, -1 mm, 0, +1 mm, and +2 mm from the beam central axis. RESULTS: The dose at the junction increases systematically as the abutment of the fields changes from a gap to an overlap. The dose nonuniformity with 1-mm gap and 1-mm overlap is about 15% underdose and overdose, respectively. CONCLUSION: Imperfect abutment of split fields due to digital display tolerance (+/-1 mm) of asymmetric collimator can cause an underdose or overdose of 15% of the delivered dose.

Head and Neck Neoplasms↗
PubMed1995

Upregulation of connexin43 gap junctions during early stages of human coronary atherosclerosis.

Interactions between cells form the framework for understanding the pathogenesis of atherosclerosis, but little information is available on the role of direct intercellular communication via gap junctions in this process. To investigate gap junction expression in the pathogenesis of human atherosclerosis, lesions representing different stages of the disease were obtained from coronary arteries of hearts removed from patients undergoing cardiac transplantation. Twelve hearts, each providing 1 to 3 segments of artery, were used in the study. Sections were examined by confocal laser scanning microscopy after immunofluorescent labeling with a specific antibody against connexin43, the major gap-junctional protein of smooth muscle cells, to permit high-definition visualization of immunolabeled gap junctions through the depth of the specimen. Double labeling using anti-connexin43 and cell type-specific antibodies demonstrated colocalization of gap junctions with smooth muscle cells but not with macrophages, a relationship confirmed by electron microscopy. Regions of intimal thickening and early atheromatous lesions showed markedly increased expression of connexin43 gap junctions between intimal smooth muscle cells compared with the undiseased vessels. This increase in gap junctions was most marked in regions of intimal thickening, semiquantitative analysis of the confocal digital images revealing a > 10-fold increase compared with the undiseased vessel. The quantity of labeled gap junctions in early atheromatous lesions, although higher than that of the undiseased vessel, was lower than that of intimal thickenings, and this trend toward reduced levels of gap junction immunolabeling with lesion progression continued, the value observed in the most advanced atheromatous lesions being lower than that of the undiseased vessel. As the quantity of gap junctions declined, their distribution became more patchy and the sizes of individual junctions larger. The results suggest that enhanced expression of gap junctions between smooth muscle cells may play a role in maintaining the synthetic phenotype during early growth of the atherosclerotic plaque.

Aged↗
PubMed1988

Discrimination between fast- and slow-twitch fibres of guinea pig skeletal muscle using the relative surface density of junctional transverse tubule membrane.

The black reaction of Golgi was used to infiltrate transverse (T) tubules in fast-twitch glycolytic (FW), fast-twitch oxidative-glycolytic (FR) and slow-twitch (S) type fibres in muscles of guinea pigs. Non-junctional (fT) and junctional (jT) segments of the T-tubule network are clearly demarcated by this technique. Digitized planimetry and direct measurements were used to determine the proportion of T-tubule network forming junctions with the sarcoplasmic reticulum (%LjT) and to estimate the surface density (surface area per fibre volume) of total and junctional T membrane. From these data, the volume density (number per fibre volume) of junctional feet was calculated. All three types of fibres have approximately equal surface density of T tubules, but the FW and FR fibres have a much higher proportion of jT. The calculated volume density of feet is twice as high in fast-twitch as in slow-twitch fibres.

Animals↗
PubMed2005

The prediction of lumbar spine geometry: method development and validation.

OBJECTIVES: To develop and validate a new method of predicting the neutral lumbar spine curve from external (non-invasive electrogoniometer) measurements. BACKGROUND: Non-invasive techniques for lumbar spine geometry prediction suffer from a lack of a complete geometry description, problems with applicability to field conditions, or both. METHODS: The study consisted of three steps. First, utilizing lateral imaging (MRI and X-ray pictures) of the lumbosacral junction, the torso geometry was described using measures of lumbar lordosis via the Cobb method. Second, the relationship between imaging based measurement of lumbar spinal curvature and externally measured torso flexion angle in the sagittal plane using a goniometer was determined. Finally, method validation was performed with an independent set of nine subjects. The predicted lumbar spine curve was determined and the prediction errors were analyzed against the measured curves from digitized lateral X-ray images of the lumbosacral junction. RESULTS: The shape of the lumbar curve was described as function of three externally measured parameters. The lumbar spine Cobb angle, segmental centroid positions (S(1)-T(12)), and segmental orientations were predicted from the external lumbar motion monitor measurements, with average precisions of 5.8 degrees , 4.4 mm, and 3.9 degrees , respectively. CONCLUSIONS: The position and orientation of each segment (vertebrae and disc), along with the lumbar spine lordosis, can be predicted in the neutral posture using data from back angular measurements. RELEVANCE: The consideration of the spine as a curve is necessary to accurately quantify and describe the forces acting along the (lumbar) vertebral column for any given loading. The method could be a very useful prediction tool for industrial and laboratory experiments, as well as analytical models.

Adult↗
PubMed2004

Novel Connexin 43 (GJA1) mutation causes oculo-dento-digital dysplasia with curly hair.

Oculo-dento-digital dysplasia (ODDD) [OMIM 164200] is a rare autosomal dominant pleiotropic disorder comprising ocular, craniofacial, and digital anomalies, caused by mutations in the gap junction alpha-1 gene (GJA1 or Connexin 43 (CX43)) [Paznekas et al., 2003]. In a Danish family affected over five generations, we found a novel mutation, 286G --> A, resulting in Val96Met. We provide an easy method for mutation detection by use of the restriction enzyme Nde1 and discuss possible pathogenetic mechanisms, arguing that loss of function cannot be excluded. This is the second article reporting ODDD mutations.

Abnormalities, Multiple↗
PubMed2001

Biometric study of the relationships between palmar neurovascular structures, the flexor retinaculum and the distal wrist crease.

During surgical exposure of the carpal tunnel it is possible to injure the neurovascular structures closely related to the flexor retinaculum, such as the superficial palmar arch and the communicating branch between the ulnar and median nerves. Because of the importance of these structures and with the purpose of increasing knowledge of anatomical details concerning to their location, a biometric study was performed on the retinaculum and the communicating branch, and between the communicating branch and the distal wrist crease, as well as between the retinaculum and the superficial palmar arch. We dissected 56 hands from 28 Brazilian formalin-preserved cadavers of both sexes (24 male) at the Federal University of São Paulo-Escola Paulista de Medicina, Brazil. The communicating branch was observed in 96.4% of cases and the superficial palmar arch in 78.6%. The communicating branch was found between the common palmar digital nerve of the 4th interosseous space (from the ulnar nerve) to the homonymous nerve of the 3rd interosseous space (from the median nerve). In males, the distance between the distal wrist crease and the site where the communicating branch originates from the ulnar component had an average of 33.9 +/- 5.5 mm on the right side and 30.2 +/- 8.2 mm on the left. The distance between the distal wrist crease and the junction of the communicating branch with the common palmar digital nerve of the 3rd interosseous space was 43.6 +/- 6.9 mm on the right and 40.2 +/- 6.2 mm on the left side. Conversely, in 14.8% of cases (1 female), the communicating branch was observed to emerge from the common palmar digital nerve of the 3rd interosseous space. The distance between the retinaculum and the superficial palmar arch in the axial line of the 4th metacarpal bone was on average 7.3 +/- 4.3 mm on the right and 8.3 +/- 3.5 mm on the left side. At the same level, the distance between the retinaculum and the communicating branch was 6.2 +/- 3.7 mm on the right side and 5.1 +/- 2.8 mm on the left. These results can be used as a reference during surgical procedures in the palmar region.

Adult↗
PubMed1999

Relationship between oral alveolar bone loss and aging among African-American and Caucasian individuals.

BACKGROUND: The periodontal attachment apparatus consists of the periodontal ligament, alveolar bone, cementum and supra-crestal connective tissue. They are interdependent and provide protection and support to the dentition. It is theorized that the integrity of the periodontal apparatus can be maintained throughout life by exercising comprehensive oral hygiene practices and routine dental care. Additionally, it appears to be unaffected by aging. As a consequence, the investigators performed a study to determine the effects of chronological aging on alveolar bone loss. OBJECTIVE: The present study was conducted to determine the relationship between oral alveolar bone loss, oral hygiene, and aging among African-American and Caucasian populations. METHODS: The population consisted of 229 individuals. There were 131 men and 98 women. With respect to race there were 89 African-Americans and 140 Caucasians. Oral examinations, oral hygiene and missing teeth determinations and bitewing radiographs were performed on all the individuals. Radiographs were digitized and measurements were made from the cementum/enamel junction to the alveolar bone crest. Measurements were made for both the maxillary and mandibular jaws. RESULTS: The results of the study showed a significant multiple linear regression model relationship between oral bone loss and aging. Oral hygiene was a factor, but contributed only slightly to the overall model. Race, gender and the number of missing teeth were not significant variables in the overall model. CONCLUSION: The results of this study suggest age-related alveolar bone loss.

Adult↗
PubMed1986

Sinusoids ultrastructure of human hepatocellular carcinoma.

Sinusoids ultrastructure was studied in a case of hepatocellular carcinoma developed in the non cirrhotic liver of a 40-year-old man. The surgical biopsy was perfusion-fixed with 1.5% glutaraldehyde. The number of Kupffer cells was very low. Endothelial cells with signs of hyperactivity were very irregular; digitations were often attached by numerous well identified junctional complexes to their own cell processes or to adjacent cell processes. Perisinusoidal cells without lipids resembled fibro-myofibroblasts. Discontinuous basement membranes underlaid endothelial cells and perisinusoidal cells. In addition numerous strands of short basement membranes segments were seen in the Disse space. Well organized bundles of collagen were not seen. The sinusoidal membranes of hepatocytes were flattened. The perfusion-fixation revealed to be a very useful technique in the identification of all these changes which have also been reported to some degree in benign liver cell adenoma and in cirrhosis; these two conditions are known to be associated with hepatocellular carcinoma.

Adult↗