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PubMed1997

Microsurgical anatomy of the transcondylar, supracondylar, and paracondylar extensions of the far-lateral approach.

Despite a large number of reports of the use of the far-lateral approach, some of the basic detail that is important in safely completing this exposure has not been defined or remains poorly understood. The basic far-lateral exposure provides access for the following approaches: 1) the transcondylar approach directed through the occipital condyle or the adjoining portions of the occipital and atlantal condyles; 2) the supracondylar approach directed through the area above the occipital condyle; and 3) the paracondylar exposure directed through the area lateral to the occipital condyle. The transcondylar approach provides access to the lower clivus and premedullary area. The supracondylar approach provides access to the region of, and medial to, the hypoglossal canal and jugular tubercle. The paracondylar approach, which includes drilling of the jugular process of the occipital bone in the area lateral to the occipital condyle, provides access to the posterior portion of the jugular foramen and to the mastoid on the lateral side of the jugular foramen. In this study, the anatomy important to completing the far-lateral approach and these modifications was examined in 12 cadaveric specimens. In the standard posterior and posterolateral approaches, an understanding of the individual suboccipital muscles is not essential. However, these muscles provide important landmarks for the far-lateral approach and its modifications. Other important considerations include the relationship of the occipital condyle to the foramen magnum, hypoglossal canal, jugular tubercle, the jugular process of the occipital bone, the mastoid, and the facial canal. These and other relationships important to completing these exposures were examined in this study.

Adult↗

PubMed2004

Retinotopy with coordinates of lateral occipital cortex in humans.

OBJECT: The lateral occipital cortex in humans is known as the "extrastriate visual cortex." It is, however, an unexplored field of research, and the anatomical nomenclature for its surface has still not been standardized. This study was designed to investigate whether the lateral occipital cortex in humans has retinotopic representation. METHODS: Four right-handed patients with a diagnosis of intractable epilepsy from space-occupying lesions in the occipital lobe or epilepsy originating in the occipital lobe received permanently implanted subdural electrodes. Electrical cortical stimulation was applied directly applied to the brain through metal electrodes by using a biphasic stimulator. The location of each electrode was measured on a lateral skull x-ray study. Each patient considered a whiteboard with vertical and horizontal median lines. The patient was asked to look at the midpoint on the whiteboard. If a visual hallucination or illusion occurred, the patient recorded its outline, shape, color, location, and motion on white paper one tenth the size of, and with vertical and horizontal median lines similar to those on, the whiteboard. Polar angles and eccentricities of the midpoints of the phosphenes from the coordinate origin were measured on the paper. On stimulation of the lateral occipital lobe, 44 phosphenes occurred. All phosphenes were circular or dotted, with a diameter of approximately 1 cm, except one that was like a curtain in the peripheral end of the upper and lower visual fields on stimulation of the parietooccipital region. All phosphenes appeared in the visual field contralateral to the cerebral hemisphere stimulated. On stimulation of the lateral occipital lobe, 22 phosphenes moved centrifugally or toward a horizontal line. From three-dimensional scatterplots and contour maps of the polar angles and eccentricities in relation to the x-ray coordinates of the electrodes, one can infer that the lateral occipital cortex in humans has retinotopic representation. CONCLUSIONS: The authors found that phosphenes induced by electrical cortical stimulation of the lateral occipital cortex represent retinotopy. From these results one can assert that visual field representation with retinotopic relation exists in the extrastriate visual cortex.

Adult↗

PubMed2002

Extreme lateral-transatlas approach for resection of the dens of the axis.

OBJECT: Various approaches have been described for resection of the dens of the axis, each of which has potential advantages and disadvantages. Anterior approaches such as the transoral route or its modifications are the most commonly used for resection of this structure. The transcondylar approach, however, which allows the surgeon to view the craniovertebral junction (CVJ) from a lateral perspective, has been introduced by Al-Mefty, et al., as an alternative approach. In this report, the authors describe the surgical technique of the extreme lateral-transatlas approach and their clinical experiences. METHODS: The authors first examined the surgical approach to the dens from a lateral perspective in five cadaveric heads. They found that removal of the lateral mass of the atlas provided adequate exposure for resection of the dens. Following this cadaveric study, the extreme lateral-transatlas approach was successfully performed at the authors' institution over a 1-year period (September 1998-August 1999) in five patients with basilar invagination due to congenital anomaly of the CVJ and rheumatoid arthritis. Furthermore, during the same procedure, unilateral occipitocervical fusion was performed following resection of the dens. In all cases complete resection of the dens was achieved using the extreme-lateral transatlas approach. This procedure provides a sterile operative field and the ability to perform occipitocervical fusion immediately following the resection. No postoperative complications or craniocervical instability were observed. The mean follow-up period was 17.2 months (range 13-24 months). CONCLUSIONS: The extreme lateral-transatlas approach for resection of the dens was found to be safe and effective. Knowledge of the anatomy of this region, especially of the V3 segment of the vertebral artery, is essential for the success of this procedure.

Adult↗

PubMedDate not supplied

Lateral incomitance in exotropia: fact or artifact?

The prevalence of significant lateral incomitance in patients with nonparetic exotropia is reported to be 22%. We speculated that measurement artifact may be the cause for some cases of apparent lateral incomitance. We measured the effective power of plastic ophthalmic prisms using a helium-neon laser in the frontal plane position and at 10 degrees, 20 degrees, and 30 degrees of rotation from the frontal plane. The rotated prisms represented the situation in which a neutralizing prism rotates with the head during measurement of lateral gaze positions. For prisms of 35 prism diopters or more, even 10 degrees of rotation produced significant artifactual incomitance. For smaller prisms, 20 degrees or more of rotation was necessary to induce significant lateral incomitance. We prospectively measured 40 consecutive patients with exotropia. Only three patients (9%) had true incomitance greater than 5 delta, and only one had incomitance in both directions of gaze. Significant lateral incomitance could be induced in every patient examined by improperly positioning the neutralizing prism. Because the detection of lateral incomitance causes most strabismus surgeons to reduce the amount of surgery they perform, special care is necessary when measuring deviations in lateral gazes.

Diagnostic Errors↗

PubMed1995

[Caloric nystagmus in the lateral recumbent position in normal subjects--the possibility of a participation of velocity storage and other non-convection factors].

To clarify the role of central velocity storage in caloric nystagmus, 20 normal subjects in the lateral recumbent position underwent recording and analysis using ENG and an infra-red video camera in darkness. The caloric stimulus was applied by pouring 10 ml of water at 20 degrees C for 20 seconds into the ear canal. After irrigation, each subject then turned to an ear-up or an ear-down lateral position. Ninety-nine percent of the rapid phases of the horizontal components were directed to the up-side ear with no relation to the irrigated ear. Sixty-six percent of the vertical components showed vertical nystagmus toward the lower eyelid, and the remaining 34% of the vertical components showed no vertical nystagmus. The direction of the torsional components was from the up-side ear to the leg with no relation to the irrigated ear. After the first phase, the nystagmus was more significantly reversed in the ear-up lateral position than in the ear-down lateral position (p < 0.01). The maximum slow-phase velocity of the first phase horizontal component and the nystagmus frequency of the first phase horizontal and vertical components were significantly smaller in the irrigated ear-up lateral position than in the ear-down lateral position (p < 0.01). The maximum slow-phase velocity of the first phase vertical component was also smaller in the ear-up lateral position (p < 0.05). However, the duration of the first phase vertical component revealed no difference between the two positions. These findings indicate that factors other than endolymph convection are involved in the first phase horizontal and vertical components. A role for central velocity storage in the vertical, components was suggested. When caloric nystagmus was analyzed as one response, including not only the horizontal component but also the vertical and torsional components, the possibility of otolithic involvement was suggested as one of the non-convection factors.

Adult↗

PubMed1999

Anatomic relationship of the cervical nerves to the lateral masses.

Eight cervical specimens were transversely sectioned with slices approximately 2 mm to 3 mm in thickness to evaluate the anatomic relationship of the spinal nerves to the lateral masses. Results showed that the spinal nerve either does not appear or, when it does, is situated anteromedially to the superior facet on the cross sections through the upper portion of the superior facet. The anterolateral aspect of the superior facet is free from the spinal nerve. Cross sections through the lower pedicle of the vertebra showed that the spinal nerve rested on the transverse process anterolateral to the lateral mass. The mean distances between the posterior midline of the lateral mass and the posterior border of the spinal nerve measured 15 degrees in the lateral direction were 16.1+/-1.7 mm for C3, 16.5+/-1.8 mm for CA, 16.8+/-1.2 mm for C5, 16.3+/-2.0 mm for C6, and 8.5+/-0.9 mm for C7. This study suggests that the anterolateral corner of the superior facet and the anterior aspect of the lateral mass lateral to the origin of the transverse process would be safer zones for screw exit. Attention should therefore be paid to the screw orientation for the Magerl technique and to the screw length for the Roy-Camille technique. Care should be taken to insert the screw into the C7 lateral mass.

Aged↗

PubMed1999

Posterior cervical arthrodesis and stabilization: an early report using a novel lateral mass screw and rod technique

OBJECTIVE: Posterior cervical arthrodesis and stabilization with lateral mass plates is a biomechanically sound construct in multiple planes of motion. It is reproducible and especially useful when the posterior elements are missing or fractured. Unfortunately, it is difficult to use in patients with severe degenerative spondylosis because the plate is malleable only in the sagittal plane and the screw positions are dictated by the plate's entry holes. METHODS: A novel system of lateral mass screws that can be positioned before placement of a lateral construct was used in nine patients. Their outcomes as well as the technical applications of this system were reviewed. RESULTS: A total of 52 screws were placed in nine patients who underwent posterior cervical arthrodesis with the Cervifix system (Synthes USA, Paoli, PA). Diagnoses included trauma in four patients, degenerative spondylosis in three, and tumor in two. Rods were molded individually according to the patient's anatomy. Compression, distraction, and lateral rotation, if indicated, were performed. Follow-up averaged 36 weeks. Lateral and anteroposterior radiographs, obtained at progressive intervals, revealed excellent fixation and screw purchase without pull-out. There were no cases of spinal cord, nerve root, or vertebral artery injury. CONCLUSION: The Cervifix system accommodates variation in anatomic size and spacing of the lateral masses, potentiating precise screw placement. The rods can be molded in multiple planes, and selective application of compressive, distractive, or lateral rotatory forces is allowed. The system is very straightforward and simple to use, and we have had good success without pseudarthrosis or complications from screw placement in our series.

Journal Article↗

PubMed2000

The cytoskeletal effector xPAK1 is expressed during both ear and lateral line development in Xenopus.

xPAK1, a probable effector of stress activated MAP-kinase SAPK1/JNK activation and cytoskeletal dynamics, was found to be ubiquitously expressed within the Xenopus laevis ear and lateral line system during the development and differentiation of these organs. xPAK1 expression was very strong in the otic placode from its condensation, and expression continued in the otic vesicle up until stage 35/36, after which it abruptly ceased. At stage 29/30 expression occurred specifically in the epithelium of the otic vesicle, which includes the prospective sensorial epithelium. Expression of xPAK1 was also observed in the lateral line system from stage 35/36, at which stage the lateral line primordia have begun to migrate from the region of the otic vesicle. Lateral line expression continued at least until stage 37/38, at which time xPAK1 was noted in association with the differentiating lateral line organs. To our knowledge, xPAK1 is the first ubiquitous lateral line marker that is also expressed in the ear. In the context of previous studies, our data suggest that xPAK1 either plays a role in the differentiation of the mechano-sensors of the auditory system or in the formation of the otic vesicle epithelium and the lateral line primordia.

Age Factors↗

PubMed2000

Far lateral lumbar disc herniation.

BACKGROUND: Far lateral lumbar disc herniation is an uncommon condition that may compress the nerve root outside the vertebral canal and in its extraforaminal course. The traditional midline interlaminar approach for the exploration of far lateral lumbar disc herniation is often difficult because the intervertebral articulation obviates a direct view of the course of the extraspinal nerve. In this report, we present two surgical approaches for the treatment of far lateral lumbar disc herniation: the paramedian muscle-splitting microtechnique and the enlarged midline approach. METHODS: Eight patients with far lateral lumbar disc herniation were found among 160 lumbar disc operations in 160 patients. According to computed tomography results, we divided patients with far lateral lumbar disc herniations into two groups; the extraforaminal and foraminal groups. Clinical presentation, imaging studies and surgical approach were thoroughly reviewed. RESULTS: Three patients in the extraforaminal group underwent the paramedian muscle-splitting microtechnique. Two patients in the foraminal group underwent the enlarged midline approach. The other three were operated on before the introduction of the paramedian muscle-splitting microtechnique and the enlarged midline approach. One of these patients who underwent the traditional interlaminar approach with resection of the lateral portion of facet joint, received additional instrumentation and fusion for the prevention of further instability. All had good results and no further surgical treatment was necessary. CONCLUSIONS: The incidence of far lateral lumbar disc herniation was 5% of all surgically treated disc herniations at our institution. For the extraforaminal group, the paramedian muscle-splitting microtechnique is the surgical route of choice. For the foraminal group, the enlarged midline approach is better than the traditional, interlaminar approach in saving the facet joint and preventing postoperative instability.

Adult↗

PubMed1985

Movement of calcium across tips of primary and lateral roots of Phaseolus vulgaris.

Calcium (Ca) movement across tips of primary and lateral roots of Phaseolus vulgaris was determined by applying 45Ca2+ to one side of the root and collecting radioactivity in an agar receiver block on the opposite side of the root. The ratios of cpm in receiver blocks on the bottom of primary roots : cpm in receiver blocks on the top of the primary roots were 1.87 and 2.47 after 1 and 2 hr, respectively. This polar transport of Ca across tips of primary roots correlated positively with a graviculture of 43 degrees after 2 hr. The ratio of cpm in receiver blocks on the bottom of lateral roots : cpm in receiver blocks on the top of lateral roots was 1.20 after 2 hr. The decreased polar movement of Ca across tips of lateral roots correlated positively with lateral roots being nongraviresponsive. These data 1) support the suggestion that gravistimulation induces polar movement Ca toward the lower side of tips of primary roots, and 2) suggest that the reduced polar movement of Ca across tips of lateral roots may be involved in uncoupling gravistimulation from gravicurvature in lateral roots.

Biological Transport↗

PubMed2002

[Dimensions of the lateral condyle in non-arthritic valgus knees. A cadaver study].

PURPOSE OF THE STUDY: Although the valgus slope of the femoral condyles seen in valgus knee is thought to be due to hypoplasia of the lateral femoral condyle, this fact has not been proved. The aim of this study was therefore to evaluate the difference between the size of the lateral femoral condyle of neutral and valgus knees. MATERIAL AND METHODS: There were 41 non-arthritics lower limbs taken from 27 caucasians donors. Angular measurements were taken with respect to the mechanical axis of the bones. Femurs were then isolated from the tibia, all soft tissue was removed with respect to the articular cartilage. An osteometric system developed for this study allowed each femur to be precisely photographed in perpendicular planes. Each femur was mounted on the osteometric system. The dimensions (depth and height) of each lateral femoral condyle were obtained using direct measurements from standardized photographs. Knees were considered neutral when the tibiofemoral mechanical angle (TFMA) was between 181 degrees and 176.6 degrees and considered valgus when over 181 degrees. To be compared, measurements were related to the transepicondylar width of each femur. The related dimensions were then compared for both categories of knees (valgus and neutral). There were 18 valgus knees (mean TFMA 182.7 degrees +/- 0.8) and 23 neutral knees (mean TFMA 179.1 degrees +/- 1.6). A validation for the technique was performed by measuring six points on a same femur by the same person seven times. This revealed standard deviations of 0.7 millimeters which was small enough for our purpose. The relationships between the related measurements were analyzed using the Mann & Whitney U test. Significance was accepted at a P value of less than 0.05. RESULTS: The related depth of the lateral femoral condyle was bigger for valgus knees 32.0 (+/- 2.5) than for the neutral knees 30.5 (+/- 2.0). The related heights of the lateral femoral condyle were about equal 28.7 (+/- 1.8). DISCUSSION: Using a population of non arthritic knees, our data demonstrated that the lateral femoral condyle is thicker in valgus knees compared to neutral knees, thus in contradiction with the most common view. We suggest that in fixed valgus knees, beside arthritic wear, there is no deficiency of the posterior lateral condyle of the femur.

Aged↗

PubMed2003

[Distribution of the lateral cutaneous nerve of the thigh in the area of intramuscular injection].

UNLABELLED: The technique of intramuscular injection (IM) into the antero-lateral region of the thigh is widely used. Nevertheless, despite this area being indicated as the second best location for this practice, the technique is still observed to be very painful for both adult and child patients. OBJECTIVE: To study the localization, distribution and course of the lateral cutaneous nerve of the thigh, and its topographic relationship with the area recommended for the practice of intramuscular injection, relating these characteristics to the pain resulting from such procedures. METHOD: By means of exposing the antero-lateral region by classical dissection, the lateral cutaneous nerve of the thigh was identified and isolated in 20 fixed adult male cadavers, giving emphasis to the viewing of its nerve rami across the iliotibial tract. RESULTS: In 100% of the cases, the lateral cutaneous nerve emerged medially in relation to the upper anterior iliac spine. After this, it issued three wide-caliber rami in 70% of the specimens and only two in the remaining 30%. In the upper third and in the upper portion of the middle third of the thigh, a network of numerous small nerve rami was observed, enveloped in a variable quantity of adipose tissue. However, in the lower portion of the middle third of the thigh and in the lower third, no significant nerve rami were seen. CONCLUSION: Based on our data, we recommend whenever possible that the distal half of the region displayed by the classical technique be utilized as the location of choice for the practice of intramuscular injection into the antero-lateral region of the thigh. This is because this region is less innervated by the lateral cutaneous nerve of the thigh, which will cause less pain in this area during such procedures, thereby affording greater comfort to the patient.

Adult↗

PubMed2003

Lumbar root compression in the lateral recess: MR imaging, conventional myelography, and CT myelography comparison with surgical confirmation.

BACKGROUND AND PURPOSE: Previous authors have shown that conventional myelography is superior to plain CT in the assessment of root compression in the lateral recess, but this question has never been evaluated with respect to MR imaging of the lumbar level. Our purpose was to assess the accuracy of MR imaging, conventional myelography, and postmyelography CT (CT myelography) of the lumbar level in identifying degenerative lateral recess root compression with surgical confirmation. METHODS: MR imaging, conventional myelography, and CT myelography of the lumbar level were assessed in the imaging of 58 lateral recesses at 38 lumbar levels in 26 patients who underwent surgery for radiculopathy with degenerative lateral recess abnormality. Each lateral recess was graded as normal, small without root compression, small with root compression, or severe root compression. RESULTS: MR imaging underestimated root compression in 28% to 29% of the cases in which root impingement was surgically confirmed. Conventional myelography underestimated root compression in only 5% to 7% of the cases and correctly predicted impingement in 93% to 95%. CT myelography underestimated root compression in 38% of the surgically confirmed cases. CONCLUSION: MR imaging significantly underestimated root compression caused by degenerative changes in the lateral recess. Although MR imaging is a superb study when used in the search for degenerative disk disease and disk protrusion, conventional myelography is a crucial supplemental study that is necessary to confirm degenerative root impingement in the lateral recess as the cause of radiculopathy.

Adult↗

PubMed1992

Communication between the femoropatellar and medial and lateral femorotibial joints in horses.

Communications between the femoropatellar, medial femorotibial, and lateral femorotibial joints were studied, using fresh equine cadaver specimens. A total of 90 specimens from 45 horses were used. Horses were randomly assigned to 3 groups with 15 horses/group. Each group was assigned an injection site (femoropatellar joint, medial femorotibial joint, or lateral femorotibial joint), and red latex was injected into the respective location of each joint in each group. Immediately after injection, the joints were flexed and extended 100 times. The stifles were frozen in slight flexion, then cut into 1-cm sagittal sections. The communications between the femoropatellar and medial and lateral femorotibial joints were determined. None of the specimens in this study had communication between all 3 joint compartments. When the femoropatellar joint was injected, 18 of 30 joints (60%) communicated with the medial femorotibial joint, and 1 of 30 (3%) communicated with the lateral femorotibial joint. Injection of the medial femorotibial joint revealed 24 of 30 (80%) joints that communicated with the femoropatellar joint, and 1 of 30 (3%) that communicated with the lateral femorotibial joint. Injection of the lateral femorotibial joint resulted in communication with the femoropatellar joint in 1 of 30 (3%) joints. Communication did not exist between the medial and lateral femorotibial joints.

Animals↗

PubMed2005

Minimally invasive lateral mass plating in the treatment of posterior cervical trauma: surgical technique.

OBJECTIVE: The technique of lateral mass fixation restores the posterior tension band and provides effective stabilization in patients with many types of traumatic injuries. However, postoperative wound pain is not uncommon. The objective of this work is to describe a modified technique of minimally invasive lateral mass plating for cervical spine trauma. METHODS: Patient 1 was a 64-year-old woman who had been in a motor vehicle accident and sustained bilateral C5-C6 facet dislocation with posterior C5-C6 distraction. She was otherwise neurologically intact, and attempts at closed reduction were not successful. Patient 2 was a 16-year-old girl who had also been in a motor vehicle accident but had an incomplete spinal cord injury. She had an unstable burst fracture of C7 with posterior C5-C6 distraction. Both patients underwent anterior cervical fusion followed by staged minimally invasive posterior fusion with good results. A dilator tubular retractor system (METRX) was used to access the bilateral lateral masses through a small midline incision under fluoroscopic guidance. Lateral mass screws were then placed by using a modified Magerl technique, securing two-hole plates on each side onto the lateral masses, performed through the METRX system. We also successfully performed four-level lateral mass plating in a cadaveric cervical spine using a 2-cm skin incision. CONCLUSIONS: We describe successful placement of lateral mass screw and plate constructs with the use of a minimally invasive approach by means of a tubular dilator retractor system. This approach preserves the integrity of the muscles and ligaments that maintain the posterior tension band of the cervical spine.

Adolescent↗

PubMed2005

[Comparison between the lateral and medial approaches in terms of functional and cosmetic results in the surgical treatment of type III supracondylar humeral fractures in children].

OBJECTIVES: We compared the functional and cosmetic results of lateral and medial approaches in the surgical treatment of type III supracondylar humeral fractures in children. METHODS: The study included two groups in which type III supracondylar humeral fractures were treated using either lateral (12 boys, 8 girls; mean age 7.2 years; range 4 to 12 years) or medial (16 boys, 4 girls; mean age 7.4 years; range 3 to 11 years) approaches and internal fixation. Functional and cosmetic results were assessed according to the criteria proposed by Flynn et al. The mean follow-up periods were 19.8 months (range 8 to 30 months) and 19.5 months (range 12 to 27 months) in the lateral and medial approach groups, respectively. Patient satisfaction was also inquired regarding the site of the incision scar. RESULTS: In the lateral approach group, functional results were excellent in 18 patients (90%), good in one patient (5%), and fair in one patient, while cosmetic results were excellent in 19 patients (95%) and good in one patient. In the medial approach group, 19 patients (95%) had excellent and one patient (5%) had good functional results, while all the patients had an excellent cosmetic result (p>0.05). Complications were seen only in the lateral approach group, including transient ulnar nerve palsy in one patient, and cubitus varus deformity due to limited range of motion in another. The satisfaction rates concerning the site of the incision scar were 25% and 70% in the lateral and medial approach groups, respectively. CONCLUSION: Although no significant differences were found between the lateral and medial approaches in terms of functional and cosmetic results, the medial approach may be more convenient due to a lower risk for ulnar nerve injury and to a greater acceptability of the medial incision scar on the part of the patients.

Bone Wires↗

PubMed1991

Protease priming of neutrophil superoxide production. Effects on membrane lipid order and lateral mobility.

Phagocyte superoxide (O2-) response is primed by a variety of physiologic compounds including the neutrophil secretory proteases cathepsin G and elastase. To study whether protease priming of neutrophil O2- response is related to changes in membrane physical state, we examined enzyme effects on the order and lateral mobility of lipid probes in intact neutrophil membranes. Exposure to cathepsin G (5 micrograms/ml) or elastase (10 micrograms/ml) caused a significant decrease in fluorescence anisotropy of the probe trimethylammonium diphenylhexatriene in neutrophil plasma membranes (0.279 to 0.256 for cathepsin G, 0.274 to 0.256 for elastase, p less than 0.02 for both), indicating a decrease in phospholipid chain order in the surface membrane bilayer. Cathepsin G and elastase also caused significant increases in membrane lipid lateral mobility as measured by excimer formation of the fluorescent probe 1-pyrenedecanoic acid (for cathepsin G, a 107% increase, and for elastase, a 44% increase in excimer/monomer fluorescence ratio, p less than 0.001). Enzyme effects on membrane structure were dependent on intact proteolytic activity, and were cell specific; the proteases had no effect on lipid order or lateral mobility in liposomes. In corollary studies, the possible association between the physical state of the polymorphonuclear leukocyte membrane and O2- generation was analyzed with the membrane modifying compounds, linoleic acid, ethanol, and cholesterol. Cell exposure to linoleic acid (1 microM) caused a significant decrease in lipid order and an increase in lipid lateral mobility along with increased O2- production to N-formyl-Met-Leu-Phe (fMLP) (191%) and phorbol myristate acetate (PMA) (39%), p less than 0.02 for each. 3 mM ethanol also augmented O2- response to fMLP (31%) and PMA (48%) and caused a significant decrease in lipid order, but did not affect lipid lateral mobility. Treatment with cholesteryl hemisuccinate (100 micrograms/ml) resulted in increased lipid order and decreased lipid lateral mobility, as well as decreased neutrophil superoxide response to fMLP (-61%, p less than 0.001) and PMA (-50%, p less than 0.02). We then examined whether modulation of membrane physical state may explain the mechanism of action of a known priming agent by studying the effects of low concentrations of a diacylglycerol. Cells treated with 10 microM 1-oleoyl-2-acetyl-sn-glycerol had a greater than 8-fold increase in superoxide response to fMLP (p less than 0.001) while demonstrating a significant decrease in lipid order (0.289 to 0.281, p less than 0.01) and a 50% increase in lipid lateral mobility (p less than 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed2006

Lateral canthoplasty--10-year experience.

Lateral canthoplasty is a useful method to restore eyelid function and to protect the ocular surfaces. The success of the procedure depends on the proper analysis of periorbital anatomy as it relates to the specific indication for lateral canthoplasty. We report the experience with 129 lateral canthoplasties with emphasis on the evaluation of newer techniques that better address anatomic and functional requirements. Between 1994 and 2004, 129 lateral canthoplasties were performed in 105 patients, only for reconstructive purpose. A variety of surgical techniques have been described for lateral canthoplasty, and the evolution of the operative technique for lateral canthoplasty has been toward an operation that corresponds with the anatomy of the individual. Indications for the procedure include senile ectropion, tumors, cicatritial retraction, trauma, entropion, and congenital cleft. The evaluation of the newer procedures of lateral canthoplasty as unique reconstructive tools will be discussed.

Blepharoplasty↗