ANZ JOURNAL OF SURGERY, Issue 1-2 2007
Prem Anand Nagaraja
Background: Surgical suture packs are opened (and external packaging removed) on the operating table prior to surgery. Some of these suture packs may not be used in the surgery for reasons of inappropriateness or change in the surgical technique or following accidental contact with a non-sterile surface. These unused sutures with their foil packs still unopened are sometimes re-sterilized using ethylene oxide to allow for reuse. This re-sterilization of unopened suture packs can be contentious, due to legislation and health regulations in developed countries. The purpose of the present paper was to measure the effect of such repeated gas sterilization on sutures. Methods: The knot tensile strength was measured for new sterile sutures and ethylene oxide re-sterilized sutures. The tests were conducted on two available brands of sutures, including both absorbable and non-absorbable synthetic sutures. Results: No statistically significant difference was observed in the tensile strengths between the two sets of sutures, before and after re-sterilization. Some foil packs showed slight crimping after re-sterilization, but remained intact. No humidity was observed inside the foil packs. Conclusions: Re-sterilization of unused suture foil packs can be carried out without loss of tensile strength. [source]

Reducing the Coefficient of Friction for Fast-Absorbing Gut Suture

DERMATOLOGIC SURGERY, Issue 12 2009
JONATHAN LEE BINGHAM MD
No abstract is available for this article. [source]

Letter: Tent Suture: Technique for Coverage of Exposed Vessel in the Neck

DERMATOLOGIC SURGERY, Issue 10 2007
ALI HENDI MD
No abstract is available for this article. [source]

Letter: Nipple Asymmetry Resulting from Lesion Excision and Use of a Purse-String Suture

DERMATOLOGIC SURGERY, Issue 8 2007
FIACS, LAWRENCE M. FIELD MD
No abstract is available for this article. [source]

Novel Face-Lift Suspension Suture and Inserting Instrument: Use of Large Anchors Knotted into a Suture with Attached Needle and Inserting Device Allowing for Single Entry Point Placement of Suspension Suture.

DERMATOLOGIC SURGERY, Issue 3 2006
Preliminary Report of 20 Cases with 6- to 12-Month Follow-Up
BACKGROUND Various suspension suture techniques exist to elevate the mid-face, jowls, and neck. OBJECTIVE To assess safety and efficacy of a new suspension suture and inserting instrument with both standard and minimal incision (no-skin-excision) face-lifts. METHODS A new type of multianchor suspension suture assembled from commercially available 2-0 absorbable monofilament material, with 5 to 9 equally spaced knots through which are secured 7 to 9 mm bits of 0 thickness similar suture material, and an attached straightened needle, was used to elevate and suspend facial tissues to temporal or mastoid fascia. The suspension sutures are placed in the deep subcutaneous tissues, just above the superficial musculo aponeurotic system (SMAS), by use of a novel, blunt instrument, which does not require a second, distal exit point. The suspension suture distal end floats free. The proximal needle end is sutured to fascia. The suture was used on 20 patients. Fourteen of them underwent pure, "no-skin-excision," suspension lifts. Six had suspension suture elevation of the mid-face in conjunction with relatively conservative open lifts. Nine- to 12-month results were evaluated. RESULTS With open face-lifts, 9- to 12-month results are excellent with significant persistence of the correction initially achieved. Resulting scars remained fine line. There were no complications. With pure suspension lifts, initial results were impressive. By 6 months, correction started to fade. By 12 months 100% of initial correction for jowls, and 80 to 100% for mid-face, appeared lost. Recovery time was 2 to 4 days. There were no significant complications. CONCLUSION Large multianchor, absorbable monofilament sutures can safely and effectively enhance results of conservative lifts, with remarkable elevation of the mid-face not achievable with simple SMAS flaps. These suspension sutures can easily and safely achieve impressive, though relatively short-term results, with a minimal incision, "no-skin-excision" technique. [source]

Use of a Deep Polypropylene Suture during Earlobe Repair: A Method to Provide Permanent Reinforcement in the Prevention of Recurrent Earlobe Tract Elongation

DERMATOLOGIC SURGERY, Issue 11 2005
Joseph F. Greco MD
Background. Cosmetic repair of elongated or lacerated earlobe tracts is a commonly encountered dermatologic procedure. For esthetic purposes, patients may choose to repierce the repaired lobe over the original site. Subsequent piercing within a scarred area potentially increases the risk of recurrent tract elongation secondary to the reduced tensile strength of the scar. Objective. To strengthen a damaged earlobe by incorporating a nonabsorbable, dermal polypropylene suture during earlobe repair. Methods. The technique is described within the text. Results. A deep polypropylene suture placed within a repaired earlobe tract provides a permanent barrier above which repiercing can be performed. Conclusion. Permanent reinforcement of the repaired earlobe serves to reduce the possibility of recurrent elongation of the earlobe tract. The technique is relevant when repeat piercing is desired over the original site. JOSEPH F. GRECO, MD, CHRISTINE S. STANKO, MD, AND STEVEN S. GREENBAUM, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS. [source]

Double Butterfly Suture for High Tension: A Broadly Anchored, Horizontal, Buried Interrupted Suture

DERMATOLOGIC SURGERY, Issue 3 2000
Helmut Breuninger MD
Background. The excision of skin lesions such as tumors, nevi, and scars frequently results in tension on surgical wound margins. This tension is commonly counteracted surgically with buried, intracutaneous, interrupted sutures of absorbable material which are anchored vertically in the corium. Method. The horizontal, buried, intracutaneous butterfly suture has been described elsewhere. It is firmly anchored in the corium, everts wound margins, and adapts them nearly as broadly as two vertical sutures. It can also be laid as a double butterfly suture, as described here, and then has the shape of an "8." This double butterfly suture is equivalent to three vertical sutures because of its broad base in the corium. Moreover, it can cope with much greater tension because of its "pulley" effect. A single double butterfly suture usually suffices for small defects, particularly when the wound edges are cut obliquely with a longer rim of epidermis. Materials. We have laid the traditional butterfly suture in more than 35,000 skin lesion excisions since 1985 and the double butterfly suture alone or as a supplement in more than 10,000 sutures since 1992. We use 2-0 to 6-0 polydioxanone for these procedures, since it has proven in trials to be the best-absorbed suture material. Results. In most cases, the resulting scars were narrow and smooth in spite of high tension. Results were unsatisfactory in only 6.2% of procedures. Conclusion. The double butterfly suture described here has the advantages of withstanding tension better while everting wound margins and requiring fewer stitches for wound closure. However, it is important that the suture knot be deeply anchored beneath the corium. [source]

Biological Materials: Mechanical Function of a Complex Three-Dimensional Suture Joining the Bony Elements in the Shell of the Red-Eared Slider Turtle (Adv. Mater.

ADVANCED MATERIALS, Issue 4 2009
4/2009)
The shell of a turtle is required to be a shield that is stiff at high loads, but must provide sufficient flexibility for respiration and locomotion at smaller loads. On p. 407, Peter Fratzl and co-workers show that these seemingly contradictory requirements are met by a self-locking material, whereby stiff bony elements are connected by a much softer suture with a complex three-dimensional shape. [source]

Mechanical Function of a Complex Three-Dimensional Suture Joining the Bony Elements in the Shell of the Red-Eared Slider Turtle

ADVANCED MATERIALS, Issue 4 2009
Stefanie Krauss
The shell of turtles is a shield which needs to be stiff at high loads but should provide sufficient flexibility for respiration and locomotion at smaller loads. We show that this seemingly contradictory requirement is met by a self-locking material, whereby stiff bony elements are connected by a much softer suture with a complex three-dimensional shape. [source]

Propagation of Tears in Pericardium From Young Bulls: Influence of the Suture

ARTIFICIAL ORGANS, Issue 3 2010
José María García Páez
Abstract The tearing of the collagen fibers of biological materials utilized in implants or bioprostheses is an important, and sometimes early cause of the failure of these devices. We studied the force necessary to propagate a tear in a biomaterial, pericardium from young bulls, and the influence of the suture. An Elmendorf pendulum capable of measuring the force necessary to tear a given length of tissue was employed. We analyzed 112 trials (70%) that proved valid after achieving the homogeneity of the samples according to their thickness, thus making the results comparable. Mean forces ranging between 19.87 and 150 N were required to propagate tears measuring from 0.25 to 2.0 cm. In the samples with a 1-cm-long suture, sewn using an edge-to-edge technique, the propagation of the tear required a mean force of 15.75 N when the suture was made of nylon and 28.73 N when Prolene was utilized. When these results were compared with the mean recorded in an unsutured control series (56.76 N), the loss of resistance was significant in both sutured series (P = 0.000 and P = 0.011, respectively). Finally, the equation that relates the force (y) with the length of the tear made in unsutured tissue (x) was also obtained: y = 58.14 + 9.62x2 (R2 = 0.924). The force necessary to produce a microtear, thus estimated, can be utilized as a parameter for comparison. [source]

Ophiolites from the Mianlüe Suture in the Southern Qinling and Their Relationship with the Eastern Paleotethys Evolution

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 1 2004
LAI Shaocong
Abstract The Mianlüe suture extends from Derni-Nanping-Pipasi-Kangxian to the Lüeyang-Mianxian area, then traverses the Bashan arcuate structure eastward to the Huashan region, and finally to the Qingshuihe area of the southern Dabie Mountains. From east to west, with a length of over 1500 km, the ophiolitic melangé associations are distributed discontinuously along the suture. The rock assemblages include ophiolite, island-arc and oceanic island rock series, indicating that there existed a suture zone and a vanished paleo-ocean basin. The Mianlüe paleo-ocean basin experienced its main expansion and formation process during the Carboniferous-Permian and closed totally in the Triassic. It belongs to the northern branch of the eastern paleotethys, separated from the northern margin of the Yangtze block under the paleotethys mantle dynamic system. [source]

Loading and Release of Ibuprofen in Multi- and Monofilament Surgical Sutures

MACROMOLECULAR BIOSCIENCE, Issue 9 2006
Raül Zurita
Abstract Summary: The preparation of mono- and multifilament sutures incorporating ibuprofen as an anti-inflammatory agent is considered. Poly(p -dioxanone) monofilament samples can be loaded by a molecular diffusion process using a swelling agent such as dichloromethane. The mechanical properties have been measured and have not shown a significant change for the ibuprofen loaded samples in knot tensile assays. The kinetics of both the loading process and the release in a Sörensen's medium at 37,°C have been investigated. Diffusion coefficients have also been estimated from film and slab poly(p -dioxanone) samples containing ibuprofen and their release behavior compared to that shown by monofilaments. Release from a coating copolymer based on lactide, , -caprolactone and trimethylene carbonate (PLA/PCA/PTMC 10/60/30) has also been studied. This coating solubilizes ibuprofen molecules well and can be used for braided sutures or when a rapid dose of ibuprofen is preferred. [source]

Unsuccessful Alloplastic Esophageal Replacement With Porcine Small Intestinal Submucosa

ARTIFICIAL ORGANS, Issue 4 2009
Thorsten Doede
Abstract:, In general, there is no perfect method for esophageal replacement under consideration of the numerous associated risks and complications. The aim of this study was to examine a new material,small intestinal submucosa (SIS),in alloplastic esophageal replacement. We implanted tubular SIS prosthesis about 4 cm in length in the cervical esophagus of 14 piglets (weight 9,13 kg). For the first 10 days, the animals were fed parenterally, supplemented by free given water, followed by an oral feeding phase. Four weeks after surgery, the animals were sacrificed. Only 1 of the 14 animals survived the study period of 4 weeks. The other piglets had to be sacrificed prematurely because of severe esophageal stenosis. On postmortem exploration, the prosthesis could not be found either macroscopically or histologically. Sutures between the prosthesis and the cervical muscles did not improve the results. Until now, the use of alloplastic materials in esophageal replacement has failed irrespective of the kind of material. As well as in our experiments, severe stenosis had been reported in several animal studies. The reasons for this unacceptable high rate of stenosis after alloplastic esophageal replacement seem to be multifactorial. Possible solutions could be transanastomotic splints, less inert materials, the decrease of anastomotic tension by stay sutures, the use of adult stem cells, and tissue engineering. [source]

The effect of scleral flap edge apposition on intraocular pressure control in experimental trabeculectomy

CLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 4 2008
Wayne Birchall
Abstract Background:, To assess the contribution of scleral flap edge apposition to intraocular pressure (IOP) control in trabeculectomy, using a previously described and validated experimental model of guarded filtration surgery. Materials and methods:, Twelve rectangular-flap trabeculectomy operations each with two apical adjustable sutures were performed on six donor human eyes connected to a constant flow infusion with real-time IOP monitoring. Three sizes of scleral flap were created: 4 × 4 mm, 16 mm2 (n = 4), 3 × 3 mm, 9 mm2 (n = 4) or 3 × 2 mm, 6 mm2 (n = 4). Sutures were tied tightly to produce high aqueous outflow resistance, and equilibrium IOP established. The lateral and posterior edges of the scleral flap were removed, the sutures tightened again, and the new equilibrium IOP measured. Results:, Following flap closure and with intact flap edges, the mean absolute IOP for all flaps (n = 12) was 19.5 ± 3.9 mm Hg (mean ± SD, range 12.4,27 mm Hg) and following flap edge excision 18.7 ± 4.4 mm Hg (range 5.6,27.9 mm Hg), demonstrating no significant difference between flaps with edge apposition compared with those without (P = 0.33). Mean relative IOP (% of baseline) was 68.4 ± 12.1% (range 40.9,94%) with intact flap edges and 65.4 ± 14.5% (range 18.5,97.2%) following flap edge excision (P = 0.31). Flaps measuring 4 × 4 mm and 3 × 3 mm behaved in a similar manner with minimal change in equilibrium IOP following excision of flap edges. Conclusions:, In this experimental model, scleral flap edge apposition is not required for generating outflow resistance. Suture tension generated during tight flap closure produces apposition of the underside of the scleral trapdoor to the underlying bed, and it is this apposition, which determines IOP. [source]

Equal Cosmetic Outcomes with 5-0 Poliglecaprone-25 Versus 6-0 Polypropylene for Superficial Closures

DERMATOLOGIC SURGERY, Issue 7 2010
LAURA B. ROSENZWEIG MD
BACKGROUND Cutaneous sutures should provide an aesthetically pleasing result. After placing subcutaneous sutures, enough absorbable suture often remains for the superficial closure. Mohs surgeons often use a nonabsorbable suture to close the superficial layer to obtain cosmetically elegant results, but using this additional suture is less cost effective than using the remaining absorbable suture. OBJECTIVES To compare the cosmetic results of simple running sutures using an absorbable suture material (5-0 poliglecaprone-25) with those of a nonabsorbable suture (6-0 polypropylene) in primary closures of suitable facial Mohs defects. MATERIALS AND METHODS Fifty-two patients with 57 facial Mohs surgery defects appropriate for multilayer primary repair had the defects prospectively randomized into a side-by-side comparison. After closure of the deep layers with 5-0 poliglecaprone-25 sutures, half of the wound was closed with a 5-0 poliglecaprone-25 simple running suture, and the other half of the wound was closed with a 6-0 polypropylene simple running suture. The investigators blindly determined the cosmetically superior side of the closure at 1 week and 4 months after suture removal. RESULTS Forty-four patients (48 total defects) completed the study. At the 4-month follow-up, 85% (41/48) did not show any difference between poliglecaprone-25 and polypropylene, 4% (2/48) had better outcomes with poliglecaprone-25, and 10% (5/48) had better outcomes with polypropylene. There was no statistically significant cosmetic difference between the two closure types. Wound complications such as infection, hematoma, and dehiscence did not occur in any of the patients. CONCLUSION In primary closures of facial defects, using 5-0 poliglecaprone-25 or 6-0 polypropylene for the superficial closure did not affect the cosmetic result. Therefore, 5-0 poliglecaprone-25 provides a comparable and cost-effective alternative to nonabsorbable sutures for epidermal approximation in layered closures. The authors have indicated no significant interest with commercial supporters. [source]

Frequency of Use of Suturing and Repair Techniques Preferred by Dermatologic Surgeons

DERMATOLOGIC SURGERY, Issue 5 2006
BETH ADAMS MD
BACKGROUND There are many closure techniques and suture types available to cutaneous surgeons. Evidence-based data are not available regarding the frequency of use of these techniques by experienced practitioners. OBJECTIVE To quantify, by anatomic site, the frequency of use of common closure techniques and suture types by cutaneous surgeons. METHOD A prospective survey of the members of the Association of Academic Dermatologic Surgeons that used length-calibrated visual-analog scales to elicit the frequency of use of specific suture techniques. RESULTS A response rate of 60% (61/101) indicated reliability of the received data. Epidermal layers were closed most often, in descending order, by simple interrupted sutures (38,50%), simple running sutures (37,42%), and vertical mattress sutures (3,8%), with subcuticular sutures used more often on the trunk and extremities (28%). The most commonly used superficial sutures were nylon (51%) and polypropylene (44%), and the most common absorbable suture was polyglactin 910 (73%). Bilayered closures, undermining, and electrocoagulation were used, on average, in 90% or more sutured repairs. The median diameters (defined as longest extent along any axis) of most final wound defects were 1.1 to 2.0 cm (56%) or 2.1 to 3.0 cm (37%). Fifty-four percent of wounds were repaired by primary closure, 20% with local flaps, and 10% with skin grafting, with the remaining 15% left to heal by second intent (10%) or referred for repair (5%). Experience-related differences were detected in defect size and closure technique: defects less than 2 cm in diameter were seen by less experienced surgeons, and defects greater than 2 cm by more experienced surgeons (Wilcoxon's rank-sum test: p=.02). But more experienced surgeons were less likely to use bilayered closures (r=,0.28, p=.036) and undermining (r=,0.28, p=.035). CONCLUSIONS There is widespread consensus among cutaneous surgeons regarding optimal suture selection and closure technique by anatomic location. More experienced surgeons tend to repair larger defects but, possibly because of their increased confidence and skill, rely on less complicated repairs. [source]

Novel Face-Lift Suspension Suture and Inserting Instrument: Use of Large Anchors Knotted into a Suture with Attached Needle and Inserting Device Allowing for Single Entry Point Placement of Suspension Suture.

Use of a Deep Polypropylene Suture during Earlobe Repair: A Method to Provide Permanent Reinforcement in the Prevention of Recurrent Earlobe Tract Elongation

A Case of Aptos Thread Migration and Partial Expulsion

DERMATOLOGIC SURGERY, Issue 3 2005
José G. Silva-Siwady MD
Background In our practice, the use of dented polypropylene suture has become a very simple, conservative, and effective procedure for lifting flabby ptosed facial tissue, improving it without surgery. As with some cosmetic procedures, we have seen complications with this technique. Objective To present a case report of migration and partial expulsion of Aptos thread (TOTAL Charm, Moscow, Russia). Methods After successful fixation of facial tissue with 10 Aptos threads (5 on each side, 3 in the upper and central cheek, and 2 in the mandibular area), the patient returned 28 days later owing to migration and partial expulsion of one of the Aptos threads. Results The expulsed thread was easily removed, and the patient was treated with antibiotic therapy without further complications. Conclusion After this experience, we can conclude that Aptos threads are an additional tool in our arsenal for the treatment of facial aging. We must be especially cautious and aware that our patients can present with previously unknown complications secondary to newly described procedures, as with this recent technique. JOSé G. SILVA-SIWADY, MD, CELINA DÍAZ-GARZA, AND JORGE OCAMPO-CANDIANI, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS. [source]

A Method of Augmenting the Cheek Area Through SMAS, subSMAS, and Subcutaneous Tissue Recruitment During Facelift Surgery

DERMATOLOGIC SURGERY, Issue 3 2003
Dominic A. Brandy MD
BACKGROUND As the human face ages, there is a depletion of fat that occurs in the submalar region. Various techniques such as fat transfers, fillers, alloplastic implants, and composite rhytidectomies have been used to augment this area in the past. OBJECTIVE To describe a technique that augments the submalar areas during facelift surgery without the use of fat transfer, fillers, alloplastic implants, or a risky composite technique. METHOD An oval is scribed over the depressed submalar areas preoperatively. During facelift surgery, a fusiform area is scribed over the SMAS. This fusiform is scribed so that the medial end is directed at the center of the submalar depression, and the lateral end is toward the posterior earlobe. A defect is created within the lateral aspect of the fusiform, but not the medial portion. The fusiform is subsequently closed with a 2-0 Ethibond suture using three horizontal mattress sutures and two interrupted sutures. Upon closure of this defect, SMAS, subSMAS, and subcutaneous tissue overlying the SMAS are recruited into the submalar defect by the simple phenomenon of dog-ear formation. Additionally, there is a component of frank elevation of the tissues inferior to the medial aspect of the fusiform and submalar space. RESULTS The aforementioned technique has been performed on 123 patients over 7 years and has resulted in consistently good improvement in the submalar space. The procedure is not difficult to learn, and good results can be achieved with initial cases. The learning curve was not found to be steep, with good results being achieved quickly. CONCLUSION Depression of the submalar space plays a significant role in creating an aged face. In the past, various fillers and/or alloplastic implants have been used to augment this region. A low-risk method is described that mobilizes SMAS, subSMAS, and subcutaneous tissues into the submalar space through the phenomenon of dog-ear formation after fusiform closure. [source]

The "Modified" Winch Stitch

DERMATOLOGIC SURGERY, Issue 10 2001
J. Michael Casparian MD
Background. The methods described to achieve intraoperative tissue expansion have drawbacks. Objective. To report an intraoperative tissue expansion technique using standard suture material and hemostats to create a "modified" winch stitch. Methods. A continuous running suture is placed with both ends left free. A "fixed" hemostat is placed above the skin at one end. After pulling at the other end with a second hemostat, a third hemostat is placed proximal to this hemostat just above the skin, which is left in place to produce stretching. The second and third hemostats are then used in an alternating pulling and holding fashion. Results. This method produces significant tissue expansion. If the desired degree of approximation is achieved, the ends of the suture can be tied together, as in the previously described winch stitch. Conclusion. The modified winch stitch is a simple and inexpensive means to facilitate closure of wounds under a significant amount of tension. [source]

Double Butterfly Suture for High Tension: A Broadly Anchored, Horizontal, Buried Interrupted Suture

Chondrocranium and skeletal development of Phrynops hilarii (Pleurodira: Chelidae)

ACTA ZOOLOGICA, Issue 4 2009
Paula Bona
Abstract The present study represents the first comprehensive contribution to the knowledge of the skeletal development of a pleurodiran turtle, Phrynops hilarii (Pleurodira, Chelidae). The most remarkable features found are: (1) absence of ascending process on pterygoquadrate cartilage; (2) presence of ossification centres for the epiotics; (3) as in other pleurodirans, dorsal ribs IX and X are ,sacralized'; (4) contact between ilium and carapace occurs later in ontogenetic development; (5) suture between ischia, pubes and plastron occurs in posthatching specimens; (6) contrary to previous interpretations, the phalangeal formula of the pes of P. hilarii is 2 : 3 : 3 : 3 : 5; (7) the hooked bone represents the fifth metatarsal. [source]

Intra-articular stabilisation of the equine cricoarytenoid joint

EQUINE VETERINARY JOURNAL, Issue 6 2008
J. CHEETHAM
Summary Reasons for performing study: The success of laryngoplasty is limited by abduction loss in the early post operative period. Objective: To determine the efficacy of polymethylmethacrylate (PMMA) in stabilising the cricoarytenoid joint (CAJ) and reducing the force on the laryngoplasty suture. Hypothesis: Injection into the cricoarytenoid joint resists the forces produced by physiological laryngeal air flows and pressures thereby reducing the force experienced by the laryngoplasty suture. Methods: Ten cadaver larynges were collected at necropsy and PMMA was injected into one CAJ at selected random. Each larynx was subjected to physiological conditions with with constant (static) or cycling (dynamic) flow. The specimens were tested sequentially in each of 4 conditions: 1) bilateral full abduction (Control 1); 2) transection of the suture on the side without PMMA; 3) bilateral abduction achieved by replacing the suture (Control 2); and 4) cutting the suture on the PMMA side. Tracheal pressure and flow and pressure in the flow chamber were recorded using pressure and flow transducers. The strain experienced by each suture during bilateral abduction (Controls 1 and 2) was measured. Statistical comparison of the 4 conditions was performed using a mixed effect model with Tukey's post hoc test for multiple comparisons. The strain gauge data were analysed by paired comparison of the regression slopes. Results: In the static and dynamic states, tracheal pressure increased and tracheal flow decreased when the suture on the non-cement side was cut (P<0.05). There was no significant difference in any outcome measure between PMMA injected into the CAJ and bilaterally abducted specimens (Controls 1 and 2) for either condition. The rate of increase in strain with increasing translaryngeal pressure was significantly less on the suture with PMMA placed in the CAJ (P = 0.03). Conclusions: These data provide strong evidence that injecting PMMA into the CAJ resists the collapsing effect of physiological airflows and pressures in vitro and reduces the force experienced by the laryngoplasty suture during maximal abduction. Potential relevance: Augmentation of prosthetic laryngoplasty with this technique may reduce arytenoid abduction loss in the early post operative period. [source]

Callosal contribution to ocular dominance in rat primary visual cortex

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2010
Chiara Cerri
Abstract Ocular dominance (OD) plasticity triggered by monocular eyelid suture is a classic paradigm for studying experience-dependent changes in neural connectivity. Recently, rodents have become the most popular model for studies of OD plasticity. It is therefore important to determine how OD is determined in the rodent primary visual cortex. In particular, cortical cells receive considerable inputs from the contralateral hemisphere via callosal axons, but the role of these connections in controlling eye preference remains controversial. Here we have examined the role of callosal connections in binocularity of the visual cortex in naïve young rats. We recorded cortical responses evoked by stimulation of each eye before and after acute silencing, via stereotaxic tetrodotoxin (TTX) injection, of the lateral geniculate nucleus ipsilateral to the recording site. This protocol allowed us to isolate visual responses transmitted via the corpus callosum. Cortical binocularity was assessed by visual evoked potential (VEP) and single-unit recordings. We found that acute silencing of afferent geniculocortical input produced a very significant reduction in the contralateral-to-ipsilateral (C/I) VEP ratio, and a marked shift towards the ipsilateral eye in the OD distribution of cortical cells. Analysis of absolute strength of each eye indicated a dramatic decrease in contralateral eye responses following TTX, while those of the ipsilateral eye were reduced but maintained a more evident input. We conclude that callosal connections contribute to normal OD mainly by carrying visual input from the ipsilateral eye. These data have important implications for the interpretation of OD plasticity following alterations of visual experience. [source]

Post-embryonic development of the Furongian (late Cambrian) trilobite Tsinania canens: implications for life mode and phylogeny

EVOLUTION AND DEVELOPMENT, Issue 4 2009
Tae-yoon Park
SUMMARY The current concept of the order Asaphida was proposed to accommodate some Cambrian and Ordovician trilobite clades that are characterized by the possession of a ventral median suture. The family Tsinaniidae was recently suggested to be a member of the order Asaphida on the basis of its close morphological similarity to Asaphidae. Postembryonic development of the tsinaniid trilobite, Tsinania canens, from the Furongian (late Cambrian) Hwajeol Formation of Korea, reveals that this trilobite had an adult-like protaspis. Notable morphological changes with growth comprise the effacement of dorsal furrows, sudden degeneration of pygidial spines, regression of genal spines, and loss of a triangular rostral plate to form a ventral median suture. Programmed cell death may be responsible for degenerating the pygidial and genal spines during ontogeny. Morphological changes with growth, such as the loss of pygidial spines, modification of pleural tips, and effacement of dorsal furrows, suggest that T. canens changed its life mode during ontogeny from benthic crawling to infaunal. The protaspid morphology and the immature morphology of T. canens retaining genal and pygidial spines suggest that tsinaniids bear a close affinity to leiostegioids of the order Corynexochida. Accordingly, development of a ventral median suture in T. canens demonstrates that the ventral median suture could have evolved polyphyletically, and thus the current concept of the order Asaphida needs to be revised. [source]

Critical appraisal of the mouse model of myocardial infarction

EXPERIMENTAL PHYSIOLOGY, Issue 4 2004
Naomi M. Degabriele
In order to critically evaluate the utility of a mouse model of myocardial infarction (MI) for therapeutic studies, we investigated survival, haemodynamic measurements and histopathology in mice with an occluding suture placed at one of three distinct sites along the left anterior descending coronary artery. The suture was placed at the atrioventricular juncture (High), or at two sites more distally towards the base (Middle and Low). In the High group, only 33% of animals survived 7 days after MI (P < 0.05 compared to all other groups). Only the Middle group had significantly reduced haemodynamics compared to sham-operated animals (maximum left ventricular pressure: 55.9 ± 3.5 versus 80.8 ± 5.1 mmHg, maximum change in pressure over time : 2003 ± 172 versus 4402 ± 491, P < 0.01). Histological examination showed morphological changes in all MI groups. The Middle group had larger lesions than the Low group (P < 0.05). Lesions in the anterior and lateral walls correlated, albeit weakly, with cardiac function. Power calculations indicated that, despite a certain amount of intragroup variation, the Middle Suture model may be useful for therapeutic studies to assess the effects of treatment on cardiac function and overall lesion size. [source]

Ophiolite-bearing mélanges in southern Italy

GEOLOGICAL JOURNAL, Issue 2 2009
Luigi Tortorici
Abstract In southern Italy two ophiolite-bearing belts, respectively involved in the Adria-verging southern Apennines and in the Europe-verging thrust belt of the northern Calabrian Arc, represent the southward extension of the northern Apennines and of ,Alpine Corsica' ophiolitic units, respectively. They form two distinct suture zones, which are characterized by different age of emplacement and opposite sense of tectonic transport. The ophiolite-bearing units of the southern Apennines are represented by broken formation and tectonic mélange associated with remnants of a well-developed accretionary wedge emplaced on top of the Adria continental margin, with an overall NE direction of tectonic transport. These units consist of a Cretaceous-Oligocene matrix, which includes blocks of continental-type rocks and ophiolites with remnants of their original Upper Jurassic to Lower Cretaceous pelagic cover. The innermost portion of the accretionary wedge is represented by a polymetamorphosed and polydeformed tectonic units that underwent a Late Oligocene high pressure/low temperature (HP/LT) metamorphism. The northern Calabria ophiolitic-belt is indeed composed of west-verging tectonic slices of oceanic rocks which, embedded between platform carbonate units of a western continental margin at the bottom and the basement crystalline nappes of the Calabrian Arc at the top, are affected by a Late Eocene-Early Oligocene HP/LT metamorphism. The main tectonic features of these two suture zones suggest that they can be interpreted as the result of the closure of two branches of the western Neotethys separated by a continental block that includes the crystalline basement rocks of the Calabrian Arc. We thus suggest that the north-east verging southern Apennine suture constituted by a well-developed accretionary wedge is the result of the closure of a large Late Jurassic-Early Cretaceous oceanic domain (the Ligurian Ocean) located between the African (the Adria Block) and European continental margins. The northern Calabria suture derives indeed from the deformation of a very narrow oceanic-floored basin developed during the Mesozoic rifting stages within the European margin separating a small continental ribbon (Calabrian Block) from the main continent. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Mesozoic,Paleogene sedimentary facies and paleogeography of Tibet, western China: tectonic implications

GEOLOGICAL JOURNAL, Issue 3 2002
Kai-Jun Zhang
Abstract In Early,Middle Triassic time, an abyssal sea covered most of the Songpan,Ganzi area, whereas a Central Tibetan Landmass, up to 400,km wide, may have stretched across the Lhasa and Western Qiangtang terrains. In Late Triassic time, the Songpan,Ganzi sea closed, the Central Tibetan Landmass receded westwards away from southern Western Qiangtang, a littoral environment dominated Eastern Qiangtang, middle Western Qiangtang, and southeastern Lhasa, a shelf environment existed only in northern and southeastern Western Qiangtang and northwestern Eastern Qiangtang, and abyssal flysch was spread along the eastern Bangonghu,Nüjiang zone. In Early,Middle Jurassic time, Songpan,Ganzi had become part of the Eurasian continent, abyssal flysch sediments stretched throughout the Bangonghu,Nüjiang zone, the Central Tibetan Landmass was only locally present in southwestern Lhasa, and the Tethyan epicontinental sea nearly covered all Tibet southwest of the Jinsajiang suture. In Late Jurassic time, oceanic flysch deposition existed only along the westernmost Bangonghu,Nüjiang zone, nearly all of Tibet was covered by coastal deposits, and shelf deposits existed only in northern Western Qiangtang and westernmost Lhasa. In the early stage of Early Cretaceous time, the majority of Qiangtang had become dry land, and a supralittoral environment dominated across the entire Lhasa terrain. However, during the late stage of the Early Cretaceous time, platform,shelf carbonates prevailed on southern Western Qiangtang and northern Lhasa. In Late Cretaceous time, the majority of Qiangtang had become emergent land, and a supratidal environment dominated Lhasa, the western rim of Western Qiangtang, and Tarim. In Paleogene time, the majority of Tibet became emergent land, and a supratidal environment existed only on the southern and western rims. The dominance of Upper Triassic,Jurassic shelf carbonates on the northwestern Eastern Qiangtang corner and the northern Western Qiangtang rim suggests a diachronous closing of the Jinsajiang paleo-Tethys ocean, first during latest Triassic time when the Eastern Qiangtang terrain collided with Asia and finally in Jurassic time when the Western Qiangtang terrain was amalgamated to Asia. Rich picotites in Upper Triassic sandstones of middle Qiangtang suggest that the Shuanghu suture could have extended along the middle of Qiangtang, and stable shelf sedimentation during Late Triassic,Middle Jurassic time in the Western Qiangtang terrain shows that the suture probably could not have formed until Middle Jurassic time. The opening time of the Bangonghu,Nüjiang mid-Tethys ocean could be Late Triassic time due to the existence of the Central Tibetan Landmass across Western Qiangtang and Lhasa during Early,Middle Triassic time. However, its opening was diachronous, at Late Triassic time in the east and at Early,Middle Jurassic time in the west. Furthermore, its closing was also diachronous, first in the east at the beginning of Late Jurassic time and later in the west in latest Jurassic to earliest Cretaceous time. Widespread upper Lower Cretaceous limestone up to 5,km thick over the northern half of Lhasa indicates that southern Tibet could have undergone an extensive backarc subsidence during late Early Cretaceous time. Continuous shallow marine sedimentation through the entire Cretaceous time over much of southern Tibet indicates that southern Tibet was intensely elevated only after the end of Paleogene time, its high topography being the product of the Indo-Asian collision. Copyright © 2002 John Wiley & Sons, Ltd. [source]