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PubMedDate not supplied

Partial reinforcement and extinction of vasomotor conditioning. A test of cognitive and two-factor theories.

In order to investigate cognitive versus traditional accounts of responding in extinction and the discrimination hypothesis for the partial reinforcement effect, 40 human subjects were randomly divided into two groups and were treated according to thermal vasomotor conditioning procedures using either 25 trials of continuous reinforcement or 100 trials of 25% partial reinforcement. At the onset of extinction, half of each group was given traditional noninformed extinction, while the other (informed) half had the thermal stimulator removed. The usual greater resistance to extinction was obtained after partial reinforcement than after continuous reinforcement in the two noninformed groups, however, immediate extinction of responding was obtained from the first extinction trial in the two informed groups. These results are consistent both with the discrimination hypothesis for the partial reinforcement extinction effect and with cognitive explanations of responding in extinction. Consequences for the behavioral therapies are discussed.

Blood Pressure↗
PubMedDate not supplied

[Collective behavior of cortical neurons upon long-term reinforcement].

The differential equation describing behaviour of a large ensemble of cortical cells under the extended action of positive or negative reinforcement is derived. The equation is based on the concept that the reinforcement changes synaptic effectiveness in the learning process and a sign of this change depends on an average pulse frequency of a presynaptic neuron and a reinforcement sign. This equation turns out to be identical to the equation which was derived by us earlier based on the ideas that the reinforcement influences on a threshold of neuronal excitation. The comparison of the equation solution with our experimental data lends support for the solution and enables to believe that the serotoninergic system of the brain is a terminal link of the positive reinforcement system and that the noradrenalinergic one is a terminal link of the negative reinforcement.

Cerebral Cortex↗
PubMed1994

A comparison of nucleus accumbens neuronal firing patterns during cocaine self-administration and water reinforcement in rats.

The firing patterns of nucleus accumbens (NA) neurons in the rat were recorded during cocaine self-administration and responding for water. Recordings were obtained from permanently implanted multiple-electrode arrays (eight microwires) inserted bilaterally into rostral portions of the NA in subjects (n = 18) exhibiting stable cocaine self-administration (0.33 mg/infusion), and during stable responding for water reinforcement. Electronically isolated and identified NA neurons exhibited four distinct patterns of phasic activity relative to the reinforced response. Three of these firing patterns were observed during both cocaine self-administration and water reinforcement sessions. Response-related activity was categorized by cells that showed an anticipatory increase in firing rate during the preresponse phase (type PR), and by cells that were excited (type RFE) or inhibited (type RFI) following the response in the reinforcement phase. PR and RFE cells showed significantly reduced peak firing during cocaine self-administration, compared to similar cells in water reinforcement sessions. A fourth type of NA firing pattern (type PR+RF) was observed only in cells recorded during cocaine self-administration sessions (Carelli et al., 1993b). PR+RF neurons exhibited two distinct peaks, one preceding the response and terminating at response completion (like PR cells), and a second peak immediately following the response (like RFE cells) with an inhibitory period between the two peaks (like RFI cells). The findings are discussed in terms of the role of the NA in mediating the reinforcing properties of both cocaine and water.

Animals↗
PubMed1993

Fluoxetine prevents the disruptive effects of fenfluramine on differential-reinforcement-of-low-rate 72-second schedule performance.

This study compared the effects of fenfluramine and fluoxetine on the differential-reinforcement-of-low-rate 72-s schedule of reinforcement. Fluoxetine, a clinically effective antidepressant, increases extracellular serotonin (5-HT) by blocking the uptake of 5-HT after release. Fenfluramine increases extracellular 5-HT through transporter-mediated release (although it also blocks 5-HT uptake). The following characteristics were identified. First, fenfluramine and fluoxetine had two different effects on the differential-reinforcement-of-low-rate 72-s schedule. Fluoxetine had an antidepressant-like effect by increasing reinforcement rate without disrupting the interresponse time distribution. Fenfluramine's effect on the differential-reinforcement-of-low-rate 72-s schedule was not antidepressant-like: it did not increase the reinforcement rate, whereas it did disrupt the interresponse time distribution. Second, when fluoxetine and fenfluramine were given in combination, fluoxetine prevented the disruptive effects of fenfluramine. This result is consistent with fluoxetine's ability to block fenfluramine-induced 5-HT release, and supports the argument that the uptake transporter mediates fenfluramine's effects on both 5-HT release and behavior. Putative behavioral mechanisms (waiting capacity and temporal discrimination) which may mediate the acute effects of fluoxetine are discussed.

Animals↗
PubMed1996

Neurotoxic lesions of basolateral, but not central, amygdala interfere with Pavlovian second-order conditioning and reinforcer devaluation effects.

Considerable evidence suggests that various discrete nuclei within the amygdala complex are critically involved in the assignment of emotional significance or value to events through associative learning. Much of this evidence comes from aversive conditioning procedures. For example, lesions of either basolateral amygdala (ABL) or the central nucleus (CN) interfere with the acquisition or expression of conditioned fear. The present study examined the effects of selective neurotoxic lesions of either ABL or CN on the acquisition of positive incentive value by a conditioned stimulus (CS) with two appetitive Pavlovian conditioning procedures. In second-order conditioning experiments, rats first received light-food pairings intended to endow the light with reinforcing power. The acquired reinforcing power of the light was then measured by examining its ability to serve as a reinforcer for second-order conditioning of a tone when tone-light pairings were given in the absence of food. Acquisition of second-order conditioning was impaired in rats with ABL lesions but not in rats with CN lesions. In reinforcer devaluation procedures, conditioned responding of rats with ABL lesions was insensitive to postconditioning changes in the value of the reinforcer, whereas rats with CN lesions, like normal rats, were able to spontaneously adjust their CRs to the current value of the reinforcer. The results of both test procedures indicate that ABL, but not CN, is part of a system involved in CSs' acquisition of positive incentive value. Together with evidence that identifies a role for CN in certain changes in attentional processing of CSs in conditioning, these results suggest that separate amygdala subsystems contribute to a variety of processes inherent in associative learning.

Acoustic Stimulation↗
PubMed1997

Evaluation of the reinforcing and discriminative stimulus effects of the N-methyl-D-aspartate competitive antagonist NPC 17742 in rhesus monkeys.

The phencyclidine (PCP)-like effects of the N-methyl-D-aspartate (NMDA) competitive antagonist 2R,4R,5S-2-amino-4,5-(1,2-cyclohexyl)-7-phosphonoheptanoic acid (NPC 17742) were evaluated in three behavioral tests in rhesus monkeys. The discriminative stimulus properties of NPC 17742 (2-24 mg/kg, i.m.) were tested in four rhesus monkeys trained to discriminate PCP from saline under a fixed-ratio (FR) 50 schedule of food reinforcement. In three of the monkeys, NPC 17742 showed complete substitution for PCP at doses which did not decrease rates of responding. Intravenous self-administration of NPC 17742 (50-800 micrograms/kg/infusion) was tested under a FR schedule of reinforcement in four monkeys trained to lever press for infusions of PCP. At least one dose of NPC 17742 functioned as a reinforcer in two of the monkeys. A second self-administration study, employing a 10 min fixed interval schedule of reinforcement, was performed in three monkeys trained to self-administer PCP during three daily sessions. Compared with PCP, NPC 17742 (0.4-1.6 mg/kg/infusion) maintained very low rates of responding; NPC 17742 could not be clearly established as a reinforcer in this procedure. The data show that NPC 17742 has some PCP-like behavioral effects, and may function as a weak reinforcer in some subjects under specific conditions. The results provide further evidence that both similarities and differences exist between the behavioral effects of PCP and competitive NMDA antagonists.

Amino Acids↗
PubMed1964

VISUAL REINFORCEMENT IN FIGHTING COCKS.

Fighting cocks were conditioned to emit a key-pecking response on a fixed ratio reinforcement schedule leading to the visual image of another fighting cock. In addition, the relative reinforcing properties of the visual reinforcer were compared with food and water reinforcers in a three-choice, non-reversible option situation. The relative reinforcing effects of mirror presentation and another rooster visually presented through a window, were compared. The mirror maintained a relatively lower response output.

Aggression↗
PubMed1996

Sustained cocaine abstinence in methadone maintenance patients through voucher-based reinforcement therapy.

BACKGROUND: Chronic cocaine abuse remains a serious and costly public health problem. This study assessed the effectiveness of a voucher-based reinforcement contingency in producing sustained cocaine abstinence. METHODS: A randomized controlled trial compared voucher-based reinforcement of cocaine abstinence to noncontingent voucher presentation. Patients were selected from 52 consecutively admitted injecting heroin abusers in a methadone maintenance treatment program. Patients with heavy cocaine use during baseline period (N = 37) participated. Except where otherwise indicated, the term cocaine abuse is used in this article in a generic sense and not according to the DSM-III-R definition. Patients exposed to abstinence reinforcement received a voucher for each cocaine-free urine sample (ie, negative for benzoylecgonine) provided three times per week throughout a 12-week period; the vouchers had monetary values that increased as the number of consecutive cocaine-free urine samples increased. Control patients received noncontingent vouchers that were matched in pattern and amount to the vouchers received by patients in the abstinence reinforcement group. RESULTS: Patients receiving vouchers for cocaine-free urine samples achieved significantly more weeks of cocaine abstinence (P = .007) and significantly longer durations of sustained cocaine abstinence (P = .001) than controls. Nine patients (47%) receiving vouchers for cocaine-free urine samples achieved between 7 and 12 weeks of sustained cocaine abstinence; only one control patient (6%) achieved more than 2 weeks of sustained abstinence. Among patients receiving vouchers for cocaine-free urine samples, those who achieved sustained abstinence ( > or = 5 weeks) had significantly lower concentrations of benzoylecgonine in baseline urine samples than those who did not achieve sustained abstinence (P < or = .01). Patients receiving voucher reinforcement rated the overall treatment quality significantly higher than controls (P = .002). CONCLUSION: Voucher-based reinforcement contingencies can produce sustained cocaine abstinence in injecting polydrug abusers.

Adult↗
PubMed1997

The NMDA antagonist, dizocilpine, enhances cocaine reinforcement without influencing mesoaccumbens dopamine transmission.

In order to assess the role of excitatory amino acids (EAAs) in the reinforcing property of cocaine, the NMDA antagonist, dizocilpine, or the AMPA antagonist, DNQX, were administered to animals previously trained to self-administer cocaine (1.0, 0.4 or 0.16 mg/kg per infusion). The highest doses of dizocilpine (0.1 mg/kg, IP) and DNQX (30 mg/kg, IP) significantly reduced operant responding for cocaine maintained on a fixed ratio schedule of reinforcement. However, whereas dizocilpine had no influence operant responding for food, DNQX significantly decreased lever pressing for this reinforcer. These results indicate that an NMDA antagonist produces a relatively selective enhancement of cocaine reinforcement, while an AMPA antagonist decreases cocaine self-administration only at a dose that also impairs responding for an alternate reinforcer. A parallel in vivo microdialysis study performed in freely moving rats tested the effects of dizocilpine alone and in combination with cocaine on extracellular dopamine in the nucleus accumbens shell. The results revealed that dizocilpine alone (0.1 mg/kg, IP) did not alter basal extracellular dopamine levels in the nucleus accumbens or spontaneous behavior. In addition, 0.1 mg/kg dizocilpine did not alter the increase in dopamine in the accumbens shell or behavioral hyperactivity produced by cocaine (15 or 30 mg/kg). Collectively, these findings suggest that dizocilpine enhances the reinforcing effect of cocaine without influencing dopamine transmission in the nucleus accumbens shell.

Animals↗
PubMed1998

The role of the pedunculopontine tegmental nucleus in relation to conditioned motor performance in the cat. I. Context-dependent and reinforcement-related single unit activity.

The activity of the pedunculopontine tegmental nucleus (PPTg) neurons was recorded in three unrestrained cats operantly conditioned to perform a lever-release movement. The movement had to be initiated either rapidly after a (click) stimulus in a simple reaction-time paradigm or had to be delayed after the same stimulus in trials identified by a tone cue. Successful trials were rewarded by a food pellet. A total of 107 neurons were recorded with microelectrodes. Brief spike neurons (mean duration: 0.7 ms) and broad spike neurons (mean duration: 2 ms) presumed to be cholinergic were detected. Of the 73 neurons localized in the PPTg area, 53 had brief spikes and 20 broad spikes. Changes in activity most commonly occurred very early after the stimulus or during the reinforcement process. Most neurons with brief spikes exhibited very early excitation after the stimulus and reinforcement-related activity. These neurons had a mean activity of 23.7 impulses/s in the period preceding the stimulus. The onset of activation after the stimulus had a latency of 8.6+/-6.9 ms (mean+/-SD), with a range of 4-35 ms. In trials where the movement had to be delayed after the stimulus, the early activation disappeared or was considerably reduced, showing that it was context-dependent. A small proportion of neurons with brief spikes initially decreased activity after the stimulus, but with a latency >9 ms. All the neurons with broad spikes, except one, had reinforcement-related activity. Half of them showed exclusively reinforcement-related activity, the other half also early activation after the stimulus. These neurons were about half as active in the period preceding the stimulus occurrence than the neurons with brief spikes. The early context-dependent activation is discussed in relation to the excitatory projection of PPTg neurons on the subthalamic nucleus. The reinforcement-related activity, preferentially evidenced in broad spike neurons presumed to be cholinergic, is speculated to be associated with cholinergic projection of PPTg neurons to the dopaminergic neurons of the substantia nigra. Finally, the role of PPTg in the ongoing control of motor performance and reinforcement processes is discussed in relation to the basal ganglia circuitry.

Action Potentials↗
PubMed2006

Laparoscopic hiatal hernia repair: long-term outcome with the focus on the influence of mesh reinforcement.

BACKGROUND: The recurrence rate after laparoscopic repair of hiatal hernias with paraesophageal involvement (LRHP) is reported to be high. Mesh reinforcement has been proposed with the objective of solving this problem. This study aimed to compare the outcome of LRHP before and after the introduction of mesh reinforcement. METHODS: Between 1992 and 2003, 56 consecutive patients received LRHP including posterior crurorrhaphy and additional fundoplication. Of these 56 patients, 17 underwent a mesh-reinforced hiatoplasty. Perioperative outcome was assessed retrospectively, and follow-up assessment was performed according to protocol including a barium contrast swallow. RESULTS: The follow-up period averaged 52 +/- 31 months (range, 9-117 months). The recurrence rate for hiatal hernia without mesh reinforcement was 19% (7/36). No recurrence (0/16) was observed in patients with mesh reinforcement. The intraoperative complication rate was 9%, and the perioperative morbidity rate was 14%. There were neither mesh-related complications nor operation-related deaths. CONCLUSIONS: Although challenging, LRPH is a successful procedure. The high recurrence rate reported in the literature can be reduced by additional mesh reinforcement.

Adult↗
PubMed1990

Pimozide prevents the response-reinstating effects of water reinforcement in rats.

Thirsty animals were trained to traverse a straight runway once each day for a reward consisting of 100 licks from a water-filled drinking tube. Once running speeds had stabilized, single daily extinction trials were initiated during which no water reinforcement was provided in the goal box. Extinction trials continued until running had slowed to levels approximately half of that observed during reinforced trials. A single treatment trial was then conducted in which some animals found water in the goal box and others continued to find an empty water bottle. Those subjects that were reinforced on treatment day subsequently demonstrated a reinstatement of their operant running response on the very next trial (i.e., 24 hr later). However, pretreatment with 1.0 mg/kg (but not 0.5 mg/kg) of the dopamine antagonist drug, pimozide, attenuated this response-reinstating effect of water-reinforcement. This action of pimozide was not likely a consequence of some residual sedative or motor incapacitation since a) the test day was conducted 24 hr after the treatment day by which time the pharmacological actions of the drug had greatly subsided; b) a Motor Control group administered pimozide after the reinforced trial exhibited normal response-reinstatement 24 hr later on Test Day; and c) on treatment day, pimozide did not reliably attenuate running times, latency to initiate drinking, nor the rate of licking behavior. Together, these data suggest that dopamine receptor antagonism can produce an attenuation in the reinforcing efficacy of water.

Animals↗
PubMed2005

Some decks are better than others: the effect of reinforcer type and task instructions on learning in the Iowa Gambling Task.

The Iowa Gambling Task (Bechara, Damasio, Damasio, & Anderson, 1994) has become widely used as a laboratory test of "real-life" decision-making. However, aspects of its administration that have been varied by researchers may differentially affect performance and the conclusions researchers can draw. Some researchers have used facsimile money reinforcers while others have used real money reinforcers. More importantly, the instructions participants receive have also been varied. While no differences have been reported in performance dependent on reinforcer type, no previous comparison of participants' instructions has been conducted. This is despite one set of instructions giving participants a clear hint about the nature of the task. Additionally, in previous research one set of instructions have not been used exclusively with one reinforcer type making any differential or cumulative effects of these factors difficult to interpret. The present study compared the effects of instruction and reinforcer type on IGT performance. When participants received instructions without a hint performance was affected by reinforcer type. This was not the case when the instructions included a hint. In a second IGT session performance was improved in participants who had received the hint instructions compared with those who had not.

Analysis of Variance↗
PubMed2005

Coil-reinforced hydrogel tubes promote nerve regeneration equivalent to that of nerve autografts.

Despite spontaneous sprouting of peripheral axons after transection injury, peripheral regeneration is incomplete and limited to short gaps, even with the use of autograft tissue, which is considered to be the "gold" standard. In an attempt to obviate some of the problems associated with autografts, including limited donor tissue and donor site morbidity, we aimed to synthesize a synthetic nerve guidance channel that would perform as well as the nerve autograft. Given that the patency of the nerve guidance channel is critical for repair, we investigated a series of nerve guidance channel designs where patency and the resulting regenerative capacity were compared in a transected rat sciatic nerve injury model. Three tube designs were compared to autograft tissue: plain, corrugated and coil-reinforced tubes of poly(2-hydroxyethyl methacrylate-co-methyl methacrylate). Of the three designs, the coil-reinforced tubes demonstrated superior performance in terms of patency. By electrophysiology and histomorphometry, the coil-reinforced tubes demonstrated outcomes that were comparable to autografts after both 8 and 16 weeks of implantation. The nerve action potential (NAP) velocity and muscle action potential (MAP) velocity for the coil-reinforced PHEMA-MMA tube was 54.6+/-10.1 and 10.9+/-1.3 m/s, respectively at 16 weeks, which was statistically equivalent to those of the autograft at 37.5+/-7.9 and 11.3+/-2.0 m/s. The axon density in the coil-reinforced tube was 2.16+/-0.61x10(4) axons/mm2, which was statistically similar to that of the autograft of 2.41+/-0.62x10(4) axons/mm2 at 16 weeks. These coil-reinforced tubes demonstrated equivalence to autografts for nerve regeneration, demonstrating the importance of channel design to regenerative capacity and more specifically the impact of patency to regeneration.

Action Potentials↗
PubMed2004

Femoroplasty-augmentation of mechanical properties in the osteoporotic proximal femur: a biomechanical investigation of PMMA reinforcement in cadaver bones.

OBJECTIVE: To determine the feasibility of polymethyl-methacrylate injection into the osteoporotic proximal femur and its effect on the mechanical properties. DESIGN: In vitro pairwise comparison of non reinforced and reinforced bones in a load to failure loading mode. BACKGROUND: Hip fractures represent an important public healthcare problem. Continued growth in the elderly population will raise the incidence of hip fractures and their associated costs dramatically in the near future. METHODS: Twenty pairs of osteoporotic femurs were mechanically tested either in a single-limb stance configuration or simulating a fall on the greater trochanter. From each pair, one femur was augmented with bone cement, with the contralateral femur serving as a control. The surface temperature at the femoral neck was recorded until twenty minutes after injection. The fracture load and the energy absorption were calculated. The Wilcoxon signed rank test was used to test for differences in fracture load and energy absorption between the reinforced femurs and the native controls. RESULTS: Volumes of 28-41 ml of cement (mean, 36 ml) could be injected. The increase of surface temperature at the femoral neck ranged from delta18.4 to delta29.8 degrees C. For the single limb stance configurations, the peak fracture load was increased by 21%, (P < 0.002) and for the simulated fall on the hip by 82%, (P < 0.002). The corresponding values for energy absorption were +48%; and +188% (P < 0.002) respectively. CONCLUSIONS: The feasibility and mechanical effectiveness of the in vitro procedure could be demonstrated. The heat generation due to polymethyl-methacrylate polymerisation is high. RELEVANCE: Prophylactic reinforcement of the femur could become a treatment option to solve the problems with osteoporotic hip fractures in patients at risk. Reinforcement materials with less exothermic reaction need to be evaluated further and also the feasibility of fracture repair after reinforcement.

Aged↗
PubMed2004

Effect of fiber position and orientation on fracture load of fiber-reinforced composite.

OBJECTIVES: The aim of this study was to determine the effect of fiber position and orientation on the initial and final fracture loads of fiber-reinforced composite (FRC). METHODS: Test specimens made of two indirect particulate composites (BelleGlass HP, Kerr, Orange, CA) or (Targis, Ivoclar Vivadent, Amherst, NY) were reinforced with ultra high molecular weight polyethylene (UHMWPE) fiber ribbon (Connect, Kerr, Orange, CA), woven E-glass fibers (Vectris Frame, Ivoclar Vivadent, Amherst, NY) or unidirectional R-glass fibers (Vectris Pontic, Ivoclar Vivadent, Amherst, NY). Fibers were placed with different positions, orientations or geometry into the rhombic test specimens (2 x 2 x 25 mm3). Control specimens did not contain fiber reinforcement. The test specimens (n=6) were stored in distilled water for 1 week at 37 degrees C before testing in a three-point loading test to determine the initial and final fracture load values. RESULTS: Initial failure loads varied from 22.6 to 172.1 N. The lowest value resulted from one UHMWPE reinforcement fiber located in diagonal orientation and the highest from two unidirectional glass fiber reinforcements, one located on the tension side and the second on the compression side. SIGNIFICANCE: Position and fiber orientation influenced the load to initial and final failure, and specimen deflection. Tension side reinforcement was most effective in increasing the load to initial and final fracture.

Analysis of Variance↗
PubMed2006

Effect of thermal cycling on composites reinforced with two differently sized silica-glass fibers.

OBJECTIVES: To evaluate the effects of thermal cycling on the flexural properties of composites reinforced with two differently sized fibers. METHODS: Acid-washed, woven, fused silica-glass fibers, were heat-treated at 500 degrees C, silanized and sized with one of two sizing resins (linear poly(butyl methacrylate)) (PBMA), cross-linked poly(methyl methacrylate) (PMMA). Subsequently the fibers were incorporated into a polymer matrix. Two test groups with fibers and one control group without fibers were prepared. The flexural properties of the composite reinforced with linear PBMA-sized fibers were evaluated by 3-point bend testing before thermal cycling. The specimens from all three groups were thermally cycled in water (12,000 cycles, 5/55 degrees C, dwell time 30 s), and afterwards tested by 3-point bending. SEM micrographs were taken of the fibers and of the fractured fiber reinforced composites (FRC). RESULTS: The reduction of ultimate flexural strength after thermal cycling was less than 20% of that prior to thermal cycling for composites reinforced with linear PBMA-sized silica-glass fibers. The flexural strength of the composite reinforced with cross-linked PMMA-sized fibers was reduced to less than half of the initial value. SIGNIFICANCE: This study demonstrated that thermal cycling differently influences the flexural properties of composites reinforced with different sized silica-glass fibers. The interfacial linear PBMA-sizing polymer acts as a stress-bearing component for the high interfacial stresses during thermal cycling due to the flexible structure of the linear PBMA above Tg. The cross-linked PMMA-sizing, however, acts as a rigid component and therefore causes adhesive fracture between the fibers and matrix after the fatigue process of thermal cycling and flexural fracture.

Composite Resins↗
PubMed2005

Functional assessment of a new staple line reinforcement in lung resection.

BACKGROUND: A major complication of lung resection is prolonged leaking at the staple line. Staple-line reinforcement is performed routinely during these procedures using bovine pericardium (peri-strips) and expanded polytetrafluorethylene. Both materials have been shown previously to increase staple-line durability and reduce the overall incidence of prolonged air leaking after lung resection, specifically in lung volume-reduction surgery. Small intestinal submucosa (SIS) has had many applications in human tissues consequent to its absorption and healing profile, which are well documented in human and animal models. However, it had not been studied in reinforcement of pulmonary staple lines. MATERIALS AND METHODS: We hypothesized that SIS reinforcement of staple lines in healthy lung tissue would increase durability, as determined by leak rates at increased airway pressures as compared to nonreinforced staple lines. Eight healthy juvenile Yorkshire-cross pigs were subjected to bilateral apical lung resections; one side was reinforced with SIS. The lungs were then inflated to sequentially increase intrabronchial pressures (5-75 cm H2O) for 60-second intervals while the chest was filled with saline under direct visualization monitoring for air leak. RESULTS: Staple lines reinforced with porcine small intestinal submucosa had significantly better durability as determined by Kaplan-Meier survival calculations with respect to leak rate as a function of pressure. CONCLUSION: Reinforcement of staple lines with SIS allows pulmonary staple lines to tolerate significantly higher intrabronchial pressures without demonstrating air leak at the staple line.

Air↗