SEARCH · PubMed Health

Results for “Clips”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 271 records · Page 15Linked to original sources

PubMed1996

Absorbable clips for cystic duct ligation in laparoscopic cholecystectomy.

BACKGROUND: The efficacy and applicability of an absorbable polydioxanone (PDS) clip for cystic duct ligation were evaluated in 297 patients undergoing laparoscopic cholecystectomy. METHODS: The indications for cholecystectomy were symptomatic gallstones (179 patients), acute cholecystitis (67), biliary pancreatitis (23), acute cholangitis (24), and gallbladder polyp (4). RESULTS: Twenty-five patients required conversion to open surgery (8.4%). The conversion rate was 2.7% for uncomplicated and 17.5% for complicated gallbladder diseases. Of the 272 patients with laparoscopic cholecystectomy, the cystic ducts were successfully ligated with PDS clips in 227 patients (83.5%). The success rate was higher in uncomplicated (163/178) than in complicated (64/94) gallbladder diseases (chi square = 24.6, P < 0.001). There was no clip-related complication on follow-up (range 0.4-39.2, median 17.5 months). In 45 patients, PDS clip failed. They were treated with endoloop (14 patients), Roeder slip knot (13), metallic clips and endoloop (8), metallic clips alone (6), and intracorporeal tie (4). CONCLUSIONS: The PDS clip is effective and applicable to the majority of patients. It should be attempted first because of the ease of application.

Absorption↗

PubMed1979

Laparoscopic sterilization with the spring clip: instrumentation development and current clinical experience.

Since the original spring clip sterilization studies were reported, a number of clinically important modifications to the spring clip and applicator have been developed. The spring-loaded clip, manufactured by Richard Wolf Medical Instruments Corporation of Chicago, Illinois, and Rocket of London, Inc., London, England, and New York, New York can be applied with either a one- or two-incision applicator and the clips and applicators currently available incorporate improvements to the original prototypes in design, manufacture, and quality control. The two-incision applicator is associated with significantly fewer misapplications and the high pregnancy rates reported with the original clip and applicator have not occurred with the current designs. Comparative studies between the clip and band have revealed less operative bleeding and pain associated with the clip. The method is appropriate to all women requesting sterilization but especially to those in the younger age group who may subsequently request reversal because of divorce and remarriage.

Female↗

PubMed1996

The invariant chain derived fragment CLIP is an efficient in vitro inhibitor of peptide binding to MHC class II molecules.

The invariant chain derived peptide CLIP inhibits association of peptides to the class II peptide binding site. Two DR3 specific peptides, the microbacterial heat shock protein 65 derived peptide hsp3-13 and the naturally occurring invariant chain derived peptide Ii131-149 were employed to study binding inhibition by CLIP (Ii82-102) in a series of combinations. Incubation of detergent solubilized DR polypeptides from Ii-free cells with 500 microM of synthetic CLIP almost completely prevents binding of 50 microM subsequently added DR3-specific peptides. When CLIP and the peptides were added simultaneously to DR3 molecules, binding of hsp3-13 was abolished, whereas binding of Ii131-149 was only partially blocked. This indicates apparent affinity differences of the peptides. The addition of CLIP to preformed DR-peptide complexes substantially reduced binding of hsp3-13,while there was little effect on the DR associated Ii131-149. The profound inhibitory ability of CLIP, which in vivo would diminish binding of antigenic peptides, suggests an intracellular mechanism that abrogates the persistence of the CLIP-DR complex. The HLA-DM molecules have been suggested as candidates for this function. The strong in vitro binding of the naturally occurring peptide Ii131-149 to DR3 may suggest that only limited amounts of this peptide are available in vivo for competition of exogenous peptide binding to class II molecules.

Amino Acid Sequence↗

PubMed2006

The functionality and reliability of an Internet interface for assessments of endoscopic still images and video clips: distributed research in gastroenterology.

BACKGROUND: Validation studies of medical images are required before the general use of new imaging techniques, and they necessitate a substantial number of observers. Multicenter studies are desirable but the logistic challenges are considerable. OBJECTIVE: The aim of the present study was to develop and test the functionality and reliability of an Internet interface for distributed evaluation of endoscopic still images and video clips. DESIGN: An Internet site for assessment of endoscopic still images and video clips was developed. To avoid limitations of the bandwidth, a solution was developed to launch and score high-quality video clips on digital video disks (DVDs) from the Internet interface. SETTING: Fifty-five observers were enrolled in the randomized, prospective multicenter study of still images. The feasibility study of video clips included 7 observers. PATIENTS: Four patients presenting with various degree of ulcerative colitis, ranging from normal to severe, were included. MAIN OUTCOME MEASUREMENTS: We tested the reliability of the interface by dual-image assessment, as well as the feasibility of Internet assessment of endoscopic images. We physically distributed high-quality DVD video footage. RESULTS: We recorded 2084 assessments of endoscopic still images and 35 assessments of video clips. The reliability of the Internet interface was confirmed by adequate repeatability and intraobserver agreement of the assessments. Video clips running from a DVD were also successfully shown on the Internet interface. Thus, high-quality video may be assessed independently of the Internet bandwidth. CONCLUSIONS: The present Internet-based tool is functional, efficient, and reliable for high-volume assessment of endoscopic images and video clips.

Colitis, Ulcerative↗

PubMed2006

Endovascular embolization vs surgical clipping in treatment of cerebral aneurysms: morbidity and mortality with short-term outcome.

BACKGROUND: Endovascular embolization of cerebral aneurysms has evolved rapidly worldwide within the last years, and has gained more popularity at the expense of surgical clipping; however, both regimens have inherent risks. This study was undertaken to asses the cerebral complications associated with both modalities of cerebral aneurysm treatment. METHODS: We retrospectively reviewed the charts, operative and embolization reports, and imaging of patients who underwent surgical clipping or embolization for cerebral aneurysms at our institution between October 2001 and October 2004. Patients were divided into 2 groups: group A, patients who had confirmed subarachnoid hemorrhage; group B, patients with unruptured cerebral aneurysms. Patients belonging to group A were evaluated according to the Hunt and Hess scale with their computed tomography scan evaluated according to Fisher scale. Short-term outcome was measured with Glasgow Outcome Scale for both groups. RESULTS: One hundred thirty-three patients with 168 aneurysms were treated; 95 (71.4%) were women and 38 (28.6%) men; mean age was 60.28 years. Hypertension (29.6%) was the most commonly encountered risk factor; average size of aneurysms treated was 7.21 mm; 53 patients belonged to group A. Seven patients were Hunt and Hess grade I, 23 grade II, 11 grade III, 7 grade IV, and 5 grade V. Eighty patients belonged to group B; for both groups, the periprocedural technical complication rate associated with coiling was 8.4% vs 19.35% with clipping. Follow-up angiographic results were better with clipping, as total aneurysm occlusion was 81.4% vs 57.5% with coiling. In group A, the incidence of angiographic vasospasm was 17.4% vs 45.4% with coiling vs clipping, whereas the incidence of shunt-dependant hydrocephalus was comparable with embolization and clipping. In group A, excellent outcome was achieved in 62% vs 44% (endovascular vs surgical) of subgroups, whereas in group B, it was 93% vs 81%, respectively. CONCLUSION: With rapidly evolving technology of endovascular embolization, accumulated experience, and good selection of patients with optimum angioanatomical criteria and endovascular accessibility, our results of morbidity and mortality associated with both modalities of cerebral aneurysm treatment with short-term outcome show that endovascular embolization of cerebral aneurysms is a safe alternative to surgical clipping in the treatment of both ruptured and unruptured cerebral aneurysms; however, long-term outcome needs to be evaluated.

Adult↗

PubMed1997

Influence of a 1 h immobilization stress on sleep states and corticotropin-like intermediate lobe peptide (CLIP or ACTH18-39, Ph-ACTH18-39) brain contents in the rat.

A 1 h immobilization stress (IS) was imposed to rats at the beginning of the dark period, i.e., when the animals start to be active. The IS was accompanied by an intense polygraphic waking and followed, over 12 h of the dark period, by a significant rebound of slow-wave sleep (SWS, +17%) and paradoxical sleep (PS, +57%). In order to estimate the IS-related changes in the endogenous concentrations of corticotropin-like intermediate lobe peptide (CLIP, ACTH18-39) and related compounds, a specific radioimmunoassay (RIA) was used. Assays performed in cerebral biopsies taken from arcuate (AN) and raphe dorsalis (nRD) nuclei led to the obtention of 2 main immunoreactive peaks, corresponding to CLIP and its phosphorylated form Ph-CLIP. Just after end of the IS and within the nRD. Ph-CLIP immunoreactivity increased by about 95%. Four hours later, i.e., when PS rebound was maximal, a 37% increase in Ph-CLIP immunoreactivity was measured in the AN. These observations have never been described before. In the blood, at the end of the restraint, CLIP/ACTH1-39 total immunoreactivity was increased by 330%. It returned to baseline level 4 h later. Blood concentration of corticosterone was also increased by 56% at the end of the IS and was close to baseline level 4 h later. Data reported here indicate that the IS first triggers an increase in Ph-CLIP within the nRD. Since the nRD contains sleep permissive components, this increase might be determinant for the SWS and PS rebound induction. The changes observed in the blood as regards CLIP/ACTH1-39 total immunoreactivity and corticosterone concentration testify to the efficacy of the IS and are part of the conventional picture accompanying such a situation. Finally, the increase in Ph-CLIP, occurring in the AN 4 h after the end of the restraint, might be part of the restorative processes necessary to compensate the stress overshoot.

Adrenocorticotropic Hormone↗

PubMed1977

Vas occlusion by tantalum clips and its comparison with conventional vasectomy in man: reliability, reversibility, and complications.

Occlusion of the vas deferens has been carried out by applying tantalum clips in 60 men. Another 50 men were vasectomized conventionally and served as controls. Vasography showed that two clips were required on each vas to bring about perfect and firm occlusion. The incidence of postoperative infection and other complications was much lower in the clip-occluded cases. Under a long-term follow-up, 10% of the conventionally vasectomized men were dissatisfied with the operation as compared with 2% of the clip-occluded group. Both groups became azoospermic within 3 months and the failure rate was zero. Removal of the clips not only was difficult but left the vas compressed and leaking. The method cannot, therefore, be considered reversible by itself. However, recanalization could easily be achieved by end-to-end anastomosis after excision of the small clipped segment or by side-to-side anastomosis without any excision. This, damage to the neuromuscular apparatus of the vas may be minimized. Male sterilization by clip occlusion has the advantages of minimal surgical intervention, shorter operative time, safety from postoperative infection, and easier recanalization if desired.

Evaluation Studies as Topic↗

PubMed1978

Structural changes in the human vas deferens after tantalum clip occlusion and conventional vasectomy.

In 15 human subjects, the vasa deferentia were occluded by applying two tantalum clips on one side and by conventional vasectomy with silk ligatures on the other. After 2 weeks, the occluded segments were recovered for histopathologic examination of serial sections. Obstructing the seminal tract did not, as such, produce any significant change in the vas: the distal and proximal segments appeared to be essentially similar and normal. At the actual site of occlusion, however, tantalum clips produced marked flattening of the tube, complete loss of lining epithelium, distortion of the muscular lamellae, and areas of hemorrhage. The lumen was converted into a narrow slit. Under the ligatures, the damage was largely confined to denudation of the mucosal epithelium. The mucosa of the intersegment left unexcised between two clips showed hyalinization, invasion by macrophages, and degeneration of the epithelium. The changes under the clips suggest that, although clip occlusion may offer several advantages, sterility cannot be reversed merely by removing the clips. The mechanisms of these changes, different in the case of clips and ligatures, are discussed and some possible long-term consequences are considered.

Epididymis↗

PubMed2003

Development and testing of a modular strain measurement clip.

A novel, multi-use, low-stiffness and low-cost transducer for measuring in vitro strains has been developed and tested. Currently available strain measurement methods are either too expensive, too complicated or too inflexible for multi-use strain measurement. The stainless-steel modular strain measurement clip introduced here was instrumented with four 350 Omega axial strain gauges in a full Wheatstone bridge configuration to take advantage of commonly available strain gauge amplifier equipment. Adjustable extension arms were designed to allow greater application versatility. The clip was calibrated and produced a linear response (R(2)>0.99) over a minimum of 1.04 mm at high amplifier gain. With reduced amplifier settings, testing showed a linear response over a range of 30.5 mm (R(2)>0.99). Clip stiffness was 0.6N/mm of extension arm tip displacement for minimal instrumentation artifact. A validation test was conducted through a comparison of strain clips, surface-mounted strain gauges and theoretical strain in an aluminium rod subjected to axial tensile loading. The two measurement techniques were used to determine the modulus of elasticity of the aluminium rod. Results were within 6% of the known modulus of elasticity for aluminium. A comparative biomechanical test was also performed on an equine third metacarpal specimen. The traditional bonded strain gauging method produced similar results as the new strain clip, but failed to measure ultimate strains since all strain gauges failed prior to specimen failure. Further investigations into the multiple uses of the clip are underway and recommendations for future versions of the clip are given.

Animals↗

PubMed2000

Radiographic evaluation of surgical clips is better than ultrasound for defining the lumpectomy cavity in breast boost treatment planning: a prospective clinical study.

PURPOSE: Breast radiotherapy (BrRT) often includes a "boost" to the lumpectomy bed. Selection of an appropriate electron energy and field size is based upon the dimensions and location of the surgical cavity. This study was performed to confirm our impression that ultrasound (US) inadequately defines the volume at risk compared to radiographic evaluation of surgical clips placed within the operative bed at the time of lumpectomy. METHODS AND MATERIALS Twenty-nine women treated with BrRT at our institution between 1996-1998 were prospectively identified as having surgical clips within the lumpectomy cavity. These patients underwent both US evaluation and radiographic evaluation of the clips to independently define two sets of transverse (T), longitudinal (L), and depth (D) measurements for each cavity. Volumes (V) were calculated for each method, assuming the cavity to be a box (V = T x L x D). Twenty-one women began BrRT following a median postoperative interval of 6 weeks (Group A), and 8 after 24 weeks (Group B) due to delivery of systemic therapy. RESULTS: Dimensions derived by US were smaller than the clip method in 22/29 of T, 25/29 of L, and 23/29 of D, or 80% of all linear measurements. A paired t-test demonstrated the difference between the methods to be statistically significant: T: p = 0.0004; L: p = 0.0001; D: p = 0.0004; and V: p = 0.0001. This underestimation by US did not fit any predictable pattern. Although the mean difference between methods (clips - US) was only 1.3, 1.9, and 1.1 cm for T, L, and D, respectively, differences ranged up to 5. 7, 9.2, and 5.5 cm for T, L, and D. The bias toward underestimation of V by US was significantly greater for Group B than Group A (p = 0. 03). CONCLUSIONS: US significantly underestimates all three dimensions of the lumpectomy cavity and hence the volume at risk compared to radiographic evaluation of surgical clips. Breast-conserving surgery should include placement of clips at the margins of the lumpectomy cavity (superior, inferior, medial, lateral, and posterior) to aid in radiotherapy treatment planning. US should not be utilized to guide the design of the boost field as it will result in inappropriate selection of lower electron energies and smaller field sizes (geographical miss), particularly among patients who receive chemotherapy prior to breast radiotherapy.

Breast Neoplasms↗

PubMed1986

Effects of antihypertensive treatment in one-clip, two kidney hypertension in rats.

In order to investigate the consequences of antihypertensive therapy on hormonal and renal parameters in one-clip, two kidney renovascular hypertension, we compared the effects of converting enzyme inhibition (CEI) with those of tripletherapy (clonidine, dihydralazine and furosemide) in this experimental model in rats. The treatment period was initiated four weeks after application of the clip and was continued for five weeks. In plasma, renin was increased and renin substrate was negatively correlated to plasma renin. Hypertension was associated with activation of the renin angiotensin system in both plasma and kidney. The degree of activation of the renin-angiotensin system in the clipped kidney and its suppression in the unclipped kidney was evaluated by two methods, renal renin content and semi-quantification of juxtaglomerular hyperplasia by immunofluorescent renin. These two methods were correlated. During the treatment period, average systolic blood pressure was 144 +/- 13 mmHg in the CEI treated group (HT1) which was not significantly different from the value found in the sham-operated group (139 +/- 4 mmHg; C2). Blood pressure, however, was lowered only to 173 +/- 18 mmHg in the group treated with tripletherapy (HT2). In control hypertensive animals, the wt of the clipped kidney did not decrease whereas significant hypertrophy was present in the unclipped kidney. Tripletherapy did not alter this relationship, whereas converting enzyme inhibition decreased kidney wt in the clipped kidney and increased further the hypertrophy of the contralateral unclipped kidney. A histological examination revealed that hypertensive microangiopathy was a predominant feature in the unclipped kidney of the untreated hypertensive group and of the group treated with tripletherapy, these lesions were completely absent in the CEI treated group. In the CEI treated group, however, ischemic lesions during this treatment were found to be decreased in the contralateral unclipped kidney and increased in the clipped kidney by comparison with untreated hypertensive rats. These renal lesions observed in the clipped kidney were most likely related to the normalization of blood pressure or to a disturbance of intrarenal mechanisms normally mediated by the renin-angiotensin system during stenosis of a renal artery.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1994

Control of renin gene expression in 2 kidney-1 clip rats.

This study was done to investigate the mechanisms that underly the changes of renal renin gene expression upon hypoperfusion of one kidney. To this end the left renal arteries of male Sprague-Dawley rats were clipped with 0.2 mm silver clips and renal renin mRNA levels were assayed by RNase protection during the first ten days after clipping. Unilateral reduction of renal blood flow led to transient maximal fivefold increases of renin mRNA levels in the clipped kidneys and to sustained suppression of renin gene expression to 20% of the control value in the contralateral intact kidneys. Inhibition of prostaglandin (PG) formation by meclofenamate or EDRF synthesis by L-NAME markedly attenuated the increase of renin mRNA levels in response to clipping, and a combination of PG/EDRF inhibition almost abolished the increase of renin mRNA levels. Inhibition of PG/EDRF formation did not change the suppression of renin mRNA levels in the contralateral intact kidneys. Neither did renal denervation nor inhibition of macula densa function by furosemide prevent the suppression of renin gene expression in response to unilateral renal artery clipping. Only converting enzyme inhibition by ramipril and blockade of Ang II-AT1 receptors by losartan attenuated the decrease of renin mRNA levels in the contralaterals to clipped kidneys. These findings suggest that intact PG and EDRF synthesis represent stimulatory signals for renin gene expression that are required for the elevation of renin mRNA levels upon unilateral renal hypoperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1982

Exchangeable sodium in rats with Goldblatt two-kidney one-clip hypertension.

1. Exchangeable sodium (NaE) was measured serially in rats given a sodium-free diet to eat with sodium chloride solution (85 mmol/l) containing 22Na to drink. 2. After 15 days, nine rats had a left renal artery clip applied; nine had a sham operation. 3. There was no significant difference in NaE between the two groups during the 6 week period after clipping, at the end of which blood pressure was 189 +/- 8 mmHg (mean +/- SEM) in the clipped group and 150 +/- 2 mmHg in the sham-operated group (P less than 0.001). 4. When the clips were removed blood pressure in the hypertensive group fell to 144 +/- 4 mmHg. 5. On the first day after removal of the clip NaE was significantly lower in the clipped group than in the sham-operated group, but there were no significant differences thereafter. 6. Total body sodium (TBNa), measured at death, was consistently higher than NaE by a mean of 1.25 +/- 0.08 mmol, in hypertensive and control rats alike. 7. We conclude that changes in sodium balance are not a necessary accompaniment of of the development of hypertension in this two-kidney one-clip rat model.

Animals↗

PubMed1984

Exchangeable sodium in Goldblatt one-kidney one-clip hypertension in the rat.

Exchangeable sodium (NaE), plasma active renin concentration and blood pressure were measured in rats with a sole remaining kidney before and after the development of hypertension induced by clipping of the single renal artery and again after unclipping. Control observations were made in sham-clipped and sham-unclipped uninephrectomized rats. Renal artery clipping caused hypertension and expansion of NaE, the latter being sustained throughout the 6 weeks during which the renal artery was constricted. Hypertension in the clipped rats was progressive over 6 weeks, whereas the expansion of NaE was not; thus the two measurements were not significantly correlated. Two rats which remained normotensive after clipping did not show expansion of NaE. Plasma active renin was elevated in comparison with the sham-clipped controls on the day after clipping, but not thereafter. Unclipping in hypertensive rats was followed by a return of NaE and blood pressure to control values. Both the sustained expansion of NaE and the transient rise in active renin probably contribute to the development of hypertension in this model, but neither alone nor together do they provide a full satisfactory explanation.

Animals↗

PubMed1998

[Reliable fixation of cochlear implant electrode mountings in children and adults--initial experiences with a new titanium clip].

BACKGROUND: There is a reported 1% incidence of delayed migration of extrusions of the electrode arrays out of the cochlea. METHODS: A titanium clip to fix the electrode array of the MED EL Combi 40 Cochlear Implant System is described. The clip is designed and shaped in a double U configuration. The clip material allows easy adaption to the individual anatomical situation. The clip is fixed to a bony bridge at the incus bar and fixes the electrode in a plane parallel to the chorda facial angle. It is closed around the electrode similarly to a stapes piston around the incus. Additional tests which examined the possible risk of damaging the electrode carrier and clinical findings are described. RESULTS: The clip was used in 23 cases with a follow-up period up to 1 year. No signs for dislocation of the electrode were found. In one revision case the clip was covered with a thin mucosal layer. The electrode array showed no signs of damage. Intraoperative findings confirmed the experimental tests on the electrode fixation. CONCLUSION: The titanium clip facilitates safe and quick fixation of the electrode array and prevents dislocation. its flexibility and shape minimizes the risk of damage.

Adult↗

PubMed2001

Facilitated coronary anastomosis using a nitinol U-Clip device: bovine model.

OBJECTIVE: The coronary anastomosis is the most difficult part of the coronary bypass procedure, particularly when using a minimally invasive technique. Methods to facilitate coronary anastomosis will make the minimally invasive approach to coronary bypass feasible. We sought preclinical validation and testing of the design and efficacy of a self-closing penetrating clip that can be used to facilitate the creation of graft-to-coronary end-to-side anastomosis. METHODS: The nitinol U-Clip device (Coalescent Surgical, Inc, Sunnyvale, Calif) was used in 13 consecutive calves (63-118 kg). In each animal, the device was (1) used to create an anastomosis of the right internal thoracic artery to a coronary artery with the heart beating and (2) compared to polypropylene suture when used to repair two carotid arteriotomies. Intraoperative, 1-week, 8-week, and 26-week postoperative angiograms and detailed histopathologic examinations were used to evaluate anastomotic patency and healing characteristics. RESULTS: The nitinol U-Clip device successfully created right internal thoracic artery-coronary artery anastomoses and repaired carotid arteriotomy sites in 13 consecutive calves. The clip was precisely placed by means of the integrated suture and needle in a fashion similar to that used for conventional suture. The clip met design specifications by reliable release and automatic closure, thereby eliminating knot tying and assisted suture management. At the time of harvest, angiography showed widely patent coronary anastomoses (FitzGibbon grade A criteria, n = 13) and carotid arteriotomy repair sites (n = 13). Histopathologic evaluation confirmed normal healing with smooth circumferential neointimal resurfacing at the anastomotic and repair sites. CONCLUSIONS: The nitinol U-Clip design and function was validated in the formation of bovine coronary anastomoses on the beating bovine heart with excellent graft patency and healing characteristics. The nitinol U-Clip device tests favorably when compared with conventional sutures in carotid artery repair.

Alloys↗

PubMed2001

A comparison of para-anastomotic compliance profiles after vascular anastomosis: nonpenetrating clips versus standard sutures.

PURPOSE: Anastomotic compliance is an important predictive factor for long-term patency of small diameter vascular reconstruction. In this experimental study we compare the compliance of continuous and interrupted sutured vascular anastomoses with those using nonpenetrating clips. METHODS: Both common carotid arteries in nine goats (average weight, 57 +/- 5.7 kg) were transected, and end-to-end anastomoses were constructed with nonpenetrating clips or polypropylene sutures. The latter were applied with both interrupted and continuous techniques. Intraluminal pressure was measured with a Millar Mikro-tip transducer, and vessel wall motion was determined with duplex ultrasound equipped with an echo-locked wall-tracking system. Diametrical compliance was determined. Environmental scanning electron microscopy was performed on explanted anastomoses. RESULTS: There was a reduction in anastomotic compliance and associated proximal and distal para-anastomotic hypercompliant zones with the use of all techniques. However, compliance loss was significantly less in those anastomoses with clips and interrupted sutures when compared with continuous suture (P <.001). Furthermore, the total compliance mismatch across anastomoses with continuous sutures was significantly greater than those with clips or interrupted sutures (P <.05). The mean time for constructing clipped anastomoses was 5.7 +/- 1.4 minutes, which was significantly less than either continuous (P <.0001) or interrupted sutures (P <.0001). Furthermore, environmental scanning electron microscopy demonstrated minimal intimal damage with good intimal apposition in the clip group. CONCLUSION: Anastomoses performed with nonpenetrating clips resulted in improved para-anastomotic compliance profiles and reduced intimal damage when compared with those with polypropylene sutures. These benefits may enhance long-term graft patency by reducing the risk of anastomotic intimal hyperplasia.

Anastomosis, Surgical↗

PubMed1995

Binding of an invariant-chain peptide, CLIP, to I-A major histocompatibility complex class II molecules.

Invariant chain (Ii) associates with major histocompatibility complex (MHC) class II molecules and is crucial for antigen presentation by class II molecules. The exact nature of Ii interaction with MHC class II molecules remains undefined. A nested set of Ii peptides, CLIPs (class II-associated Ii peptides), have been eluted from various MHC class II molecules, suggesting that CLIPs correspond, at least in part, to the Ii motif which blocks the conventional peptide binding site in MHC class II molecules. Here we report how CLIPs interact with class II MHC molecules, I-A. We have identified regions critical for binding of CLIPs and I-A class II molecules. In most cases, the binding of CLIPs to a number of I-A molecules is modulated by the steric bulk of methionine residues at positions 93 and 99. In addition, the binding of CLIPs to an I-A molecule, I-Au, is sensitive to substitutions at aspartic acid-59 in the alpha chain and threonine-86 in the beta chain, whereas the binding of an antigen-derived peptide is not. Taken together, these results provide an insight as to how CLIPs bind to MHC class II heterodimers.

Animals↗