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PubMed2004

How do general surgery replacement residents match up with those recruited through the National Resident Matching Program?

BACKGROUND: Although the scope and patterns of attrition of general surgery residents have been reported, no study has examined the residents who replaced them. The purpose of this study was to assess the quality of replacement residents (RRs). METHODS: A questionnaire asked program directors (PDs) about the prevalence, characteristics, and disposition of RRs in general surgery residency programs from 2001 to 2002. RESULTS: PDs from 169 programs (67%) responded, and 109 (64%) of these programs had RRs. Of 244 RRs (7%), 18 (7%) were postgraduate year (PGY)-1 residents; 64 (26%) were PGY-2 residents; 77 (32%) were PGY-3 residents; 52 (21%) were PGY-4 residents; and 33 (14%) were PGY-5 residents. RRs averaged 1.9 years in their programs. One hundred seventy-five (72%) came from outside the current institution, and 142 had (58%) graduated from U.S. medical schools. PDs judged RRs to be superior (20%), comparable (55%), or inferior (25%) to their peers. Neither internal recruitment nor United States medical school graduation predicted performance. Disposition included promotion and graduation (88%), leaving the program voluntarily (5%), repeating the year (4%), and dismissal (3%). Successful RR performance occurred in 71% of RRs. CONCLUSIONS: Typically, RRs were U.S. medical school graduates, were recruited from outside the institution, and have performed satisfactorily.

Career Choice↗
PubMed2006

Meniscal repair for anterior horn tear of the lateral meniscus.

This technical note describes all-inside meniscal repair for anterior horn tears of the lateral meniscus. A modified anteromedial portal is created for use in visualizing the anterior horn of the lateral meniscus. A crescent-shaped suture hook loaded with a polydioxanone suture (PDS) is inserted through an anterolateral portal. The hook tip penetrates the meniscal peripheral rim and advances across the tear. The suture hook penetrates the mobile central fragment. A leading limb of the PDS is advanced into the knee joint. Then, the leading limb of the suture is retrieved back to the anterolateral portal. With 2 limbs of PDS, endoscopic knot tying is done. With this simple technique, vertically oriented all-inside meniscal repair of an anterior horn tear of the lateral meniscus with the use of absorbable suture materials is easily performed.

Absorbable Implants↗
PubMed2006

New meniscus repair technique for peripheral tears near the posterior tibial attachment of the posterior horn of the medial meniscus.

We introduce a suture technique to repair a peripheral tear near the posterior tibial attachment of the posterior horn. A suture hook was inserted through the posteromedial portal, and the peripheral capsular rim was penetrated from superior to inferior by the sharp hook. Both relay limbs were brought out through the posteromedial portal. The outer limb of the superior peripheral capsular rim was identified with a hemostat. An 18-gauge spinal needle loaded with a No. 0 polydioxanone suture (PDS) was introduced into the joint from the anteromedial portal; it was passed through the joint space until it penetrated the inner torn meniscus. The PDS suture loaded within the needle was pushed into the joint and picked up through the posteromedial portal. The needle was pulled out of the torn meniscus and readvanced over it while the suture was kept loaded. The other limb of the suture from the tip of the spinal needle was retrieved through the posteromedial portal. The initial PDS suture limb was hooked to the shuttle-relay system; it then was passed through the inner torn meniscus and the peripheral capsular rim. The suture limb exiting from the peripheral capsular rim was used as a post and was joined to the other suture limb to form a sliding knot.

Arthroscopy↗
PubMed2005

Exaggeration of epileptic-like patterns by nicotine receptor activation during the GABA withdrawal syndrome.

To understand how nicotinic cholinergic receptors may participate in epileptic seizures, we tested the effects of nicotine and of the competitive nicotinic antagonists dihydro-beta-erythroidine and alpha-bungarotoxin on synaptic paroxysmal depolarization shifts (PDSs) and intrinsic bursts of action potentials recorded in slices from rats presenting a cortical status epilepticus. This model named GABA-withdrawal syndrome (GWS) appears consecutive to the interruption of a prolonged intracortical GABA infusion. Effects of both nicotinic antagonists suggest a distinct involvement of alpha4-beta2 and alpha7 subunits in shaping individual PDSs and patterning repetitive bursts. On one hand, in GWS rats, an increase of PDS latency and prolongation of PDS and bursts were induced by nicotine and reduced by dihydro-beta-erythroidine, but not by alpha-bungarotoxin. The K+ blocker tetraethylammonium also increased duration without changing latency. Thus, dihydro-beta-erythroidine-sensitive receptors exert distinct controls on the presynaptic generation of PDS and on the process which terminates PDSs and bursts. On the other hand, alpha-bungarotoxin depolarized neurons and generated rhythmic discharges of clustered bursts. Clustered bursts were also observed in slices obtained from GWS rats treated with the acetylcholinesterase inhibitor eserine. We suggest that both dihydro-beta-erythroidine and alpha-bungarotoxin-sensitive sites control paroxysmic activities in GWS and could be involved in some human and animal epilepsies presenting mutations of nicotinic cholinergic receptors.

Animals↗
PubMed2004

Beliefs in personality disorders: a test with the personality disorder belief questionnaire.

The hypothesis that each personality disorder (PD) is characterized by a specific set of beliefs was tested in a sample of 643 subjects, including non-patient controls, axis-I and axis-II patients, diagnosed with SCID-I and -II interviews. Beliefs of six PDs (avoidant, dependent, obsessive-compulsive, paranoid, histrionic, borderline) were assessed with the Personality Disorder Belief Questionnaire (PDBQ). Factor analyses supported the existence of six hypothesized sets of beliefs. Structural equation modeling (SEM) supported the hypothesis that each PD is characterized by a specific set of beliefs. Path coefficients were however in the medium range, suggesting that PDs are not solely determined by beliefs. Nevertheless, empirically derived cutoff scores of the six belief subscales were reasonably successful in classifying subjects, percentages ranging form 51% to 83%. It appeared that there was a monotonical increase in scores on each belief subscale from non-patient controls, to patients without any PD, to patients with PDs (other than the pertinent PD), to patients with the pertinent PD. This suggests that PD-related beliefs are at least partly associated with (personality) psychopathology in general. Another explanation is that many patients' position on the underlying dimensions is not high enough to lead to a DSM PD diagnosis, but high enough to lead to an elevated belief score.

Adult↗
PubMed2004

A novel technique using customised templates for the application of fractionated interstitial HDR brachytherapy to the tumour bed in soft-tissue sarcomas located in the extremities.

AIMS: Postoperative interstitial brachytherapy of limbs is challenging, because it is difficult to deliver a conformal dose to the tumour bed. We developed and assessed a new surgical fixation system for positioning guiding tubes in interstitial brachytherapy in order to achieve favourable geometry. MATERIALS AND METHODS: A 28-year-old patient was treated with postoperative interstitial brachytherapy boost followed by external radiotherapy after the 11th recurrence of a desmoid tumour in the forearm. On the basis of preoperative imaging data, customised resorbable templates made of polydioxanone (PDS) were cut to fit in the space left by the resected tumour. These were strategically positioned in the tumour bed during surgery. In order to hold the brachytherapy-guiding tubes parallel for the duration of treatment, they were passed through a series of holes bored into the templates. RESULTS: Fixing the guiding tubes with PDS templates resulted in a fixed geometry, and thus in an optimal dose distribution with only little additional dose optimisation needed by the brachytherapy treatment planning system. An optimised dose to the tumour bed, and a reduction of dose to critical normal tissues, is achievable with this template system for sarcomas located between osseous structures. CONCLUSION: The PDS templates offer a more rigid fixation of the guiding tubes in relation to the surrounding anatomy even after the operation cavity has been closed. A tailored dose distribution can be achieved, thus reducing possible side-effects. Additionally, because of the self-resorbable nature of the material, a re-operation for template removal is not necessary. The potential advantages of this method are being further investigated.

Adult↗
PubMedDate not supplied

Relationships between major depressive disorder and comorbid anxiety and personality disorders.

OBJECTIVE: The aim of the study was to examine whether comorbid anxiety disorders influence depressed patients' likelihood of meeting criteria for a personality disorder (PD) and whether comorbid anxiety disorders influence the stability of the PDs in patients with remitted depression. METHODS: The initial sample consisted of 373 outpatients who met criteria for major depressive disorder (MDD) (by Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition-Patient Edition) and who were enrolled in the 8-week acute treatment phase of a study of fluoxetine for MDD. Sixty-four subjects who responded to fluoxetine treatment in the acute phase met criteria for remission throughout a 26-week continuation phase during which they remained on fluoxetine with or without cognitive behavioral therapy. Stability of PDs was defined as meeting criteria for a PD at both beginning and end point of the continuation treatment phase. RESULTS: Before fluoxetine treatment, anxious depressed patients (defined as meeting criteria for MDD as well as at least one comorbid anxiety disorder) were significantly more likely to meet criteria for any comorbid PD diagnosis compared with depressed patients without comorbid anxiety disorders. In particular, there was a significant relationship between the presence of Cluster A and C PDs and the presence of anxious depression at baseline before antidepressant treatment. After successful treatment of MDD, we found a significant relationship between anxious depression diagnosed at baseline and the stability of a Cluster C PD diagnosis. CONCLUSION: Anxious depression may place patients at greater risk of having a PD diagnosis, especially one from Cluster A or C. Once the depression remits, patients who initially met criteria for anxious depression may be more likely to maintain a Cluster C PD diagnosis compared with patients initially diagnosed with MDD alone.

Adult↗
PubMed2006

Disentangling depressive personality disorder from avoidant, borderline, and obsessive-compulsive personality disorders.

Several studies have found that 3 personality disorders (PDs) tend to share moderate rates of comorbidity with depressive PD: avoidant, borderline, and obsessive-compulsive. This study sought to evaluate the diagnostic criteria of each disorder in an effort to understand where areas of overlap may occur and to modify criteria sets where reasonable to reduce any degree of overlap. One thousand two hundred psychiatric outpatients were interviewed with the Structured Interview for DSM-IV Personality Disorders. The highest degree of comorbidity was observed between avoidant PD and depressive PD. Logistic regression analyses indicated that 2 criteria-avoidant criterion 5 and depressive criterion 2-could be removed from the diagnostic criteria sets and reduce the rates of overlap by as much as 15%. A factor analysis of the criteria of all 4 PDs indicated that there is a common clustering of many of the symptoms of avoidant, borderline, depressive, and obsessive-compulsive PDs and that borderline symptoms tend to cluster together most consistently. Avoidant and obsessive-compulsive personality symptoms clustered in ways that may reflect a problem of how to engage with others, suggestive of an approach-avoidance conflict. Depressive PD symptoms clustered in a way suggestive of problems with anger that is directed toward oneself and others. The factor analysis results suggest that an organization of symptoms around themes of conflict may provide useful ways of understanding the personality patterns of these 4 disorders.

Adult↗
PubMed2005

Cortical plasticity associated with stuttering therapy.

UNLABELLED: Neuroimaging studies have indicated that persistent developmental stuttering (PDS) may be associated both with an abnormality in white matter of left-hemispheric speech areas and a right-hemispheric hyperactivity. The latter may compensate for the deficient structural connectivity in the left hemisphere. To investigate the effects of stuttering therapy on brain activity nine male adults with PDS underwent functional magnetic resonance imaging (fMRI) before and within 12 weeks after fluency shaping therapy. Brain response differences during overt sentence reading before and after therapy were assessed by utilizing random effects analyses. After therapy, a more widespread activation was observed in frontal speech and language regions and temporal areas of both hemispheres, particularly and more pronounced on the left side. Interestingly, distinct posttreatment left-sided activation increases were located directly adjacent to a recently detected area of white matter anomaly [M. Sommer, M.A. Koch, W. Paulus, C. Weiller, C. Buchel (2002). Disconnection of speech-relevant brain areas in persistent developmental stuttering. The Lancet, 360, 380-383] suggesting that fluency shaping techniques reorganize neuronal communication between left-sided speech motor planning, motor execution, and temporal areas. Hence, a therapeutic mechanism can be assumed to remodel brain circuitry close to the source of the dysfunction instead of reinforcing compensation via homologous contralateral brain networks. EDUCATIONAL OBJECTIVES: The reader will learn about and be able to: (1) describe brain activation changes detected shortly after fluency-shaping therapy; (2) identify left-hemispheric regions where a (re)functionalization after fluency-shaping therapy seems to occur adjacent to a recently described abnormal white matter region in PDS subjects; and (3) discuss how an effective cerebral compensation mechanism for stuttering could work.

Adult↗
PubMed2004

Continuous periaortic infusion improves doxycycline efficacy in experimental aortic aneurysms.

OBJECTIVE: We created a novel continuous infusion system to evaluate the efficacy of juxta-aortic doxycycline delivery as a transitional step toward developing hybrid drug/device treatment strategies for abdominal aortic aneurysm (AAA) disease. METHODS: Controlled comparison of treatment outcomes was studied in animal models with molecular and morphologic tissue analysis in a collaboration between university and corporate research laboratories. Rat AAAs were created via porcine pancreatic elastase (PPE) infusion and grouped and analyzed by subsequent treatment status (either doxycycline in vehicle or vehicle alone) and drug delivery method (continuous infusion via periaortic delivery system [PDS] or twice-daily subcutaneous injection). The main outcome measures were AAA diameter via direct measurement, medial elastin lamellar preservation via light microscopy, mural smooth muscle cell (SMC) proliferation and SMC and macrophage density via immunostaining and counting, expression of matrix metalloproteinases 2, 9, and 14 and tissue inhibitors of metalloproteinases 1 and 2 via real-time reverse transcriptase-polymerase chain reaction, and enzymatic activity via substrate zymography. Serum drug levels were analyzed via liquid chromatography/mass spectroscopy. RESULTS: PDS (1.5 mg/kg/day) and subcutaneous (60 mg/kg/day) delivery methods caused comparable reductions in AAA diameter during the period of 14 days after PPE infusion. PDS rats gained more weight during the postoperative period (P <.001), possibly as a result of reduced serum drug levels and systemic toxicity. Doxycycline treatment reduced AAA macrophage infiltration and SMC proliferation significantly. Despite reduced diameter, circumferential elastic lamellar preservation was not apparent in doxycycline-treated AAAs. CONCLUSIONS: Continuous periaortic infusion lowers the effective doxycycline dose for experimental AAA limitation. Alternative biologic inhibition strategies might also be amenable to direct intra-aortic or juxta-aortic delivery. Periaortic infusion might improve the clinical outcome of minimally invasive AAA treatment strategies. Clinical relevance Aneurysm remodeling may continue after successful endovascular AAA exclusion. Continued proteolytic activity within the aneurysm wall potentiates late graft migration and failure. The doxycycline infusion system developed in these experiments may serve as a prototype for adjuvant treatment modalities that complement endovascular AAA exclusion. Local delivery of doxycycline or other agents active in AAA disease, either continuously or at selected intervals after graft implantation, may stabilize the wall and aid in maintaining aneurysm exclusion. Alternative delivery methods could include passive diffusion from either the graft material itself or treatment reservoirs incorporated into endografts. Given the recognized limitations of current technologies, adjuvant biologic therapies have the potential to improve long-term patient outcome significantly after endovascular exclusion.

Animals↗
PubMed2006

The cortical network for eye-hand coordination and its relevance to understanding motor disorders of parietal patients.

Cortical neurons in both superior (SPL) and inferior (IPL) parietal lobules are modulated by a variety of signals concerning planning and execution of eye and hand movement. Thanks to these properties, parietal neurons are ideally suited for eye-hand coordination during reaching. In SPL, a fundamental feature of neurons is the invariance of their directional tuning properties across tasks that require different forms of spatial relationships between the eye and the hand. In such conditions, the orientation of the preferred directions (PDs) of individual SPL cells cluster within a limited sector of space, the global tuning field (GTF), to be regarded as an ideal frame to dynamically match eye and hand signals on the basis of the orientation of their PDs. At the population level, the mean vectors of the GTF cover the direction continuum in a uniform fashion. These neurons are part of a parietal network richly interconnected with the premotor and motor areas of the frontal lobe. Thus, the reaching disorders of patients with optic ataxia might be interpreted as a consequence of the breakdown of the combinatorial mechanisms of the GTF of parietal neurons, and of their interplay with premotor cortex. In IPL, the main feature of eye and/or hand related neurons is the uneven distribution of their PDs, that mostly point toward the contralateral space. This anisotropy of the representation of directional motor space might explain the movement disorders that characterize directional hypokinesia in neglect patients. In conclusion, the study of the dynamic properties of parietal neurons and of their relationships with the premotor cortex via cortico-cortical connections provides a basis for an interpretation of movement disorders of parietal patients from a neurophysiological perspective.

Animals↗
PubMed2005

Measuring the burden of premature mortality in Pakistan: use of sentinel surveillance systems.

INTRODUCTION: In developing countries, finding valid and reliable data is a great challenge. The Federal Bureau of Statistics in Pakistan maintains a surveillance system that records vital events. Results are reported as the Pakistan Demographic Survey (PDS). METHODS: The adjusted mortality data from PDS-1997 was used to estimate the burden of premature mortality using the healthy life year (HeaLY) methodology. RESULTS: The burden of premature mortality for Pakistan was 367 HeaLYs lost per 1000 population. More than half of the HeaLYs are being lost due to infection, maternal and perinatal conditions, and malnutrition. CONCLUSION: In the absence of a system maintaining reliable information regarding vital events, PDS provides a good alternate source of such information that can be used to aid policy making for health care and future research.

Adolescent↗
PubMed2005

Risk of periodontal defects after third molar surgery: An exercise in evidence-based clinical decision-making.

OBJECTIVE: The object of this study was to apply evidence-based principles to answer the question, What is the risk of having periodontal defects on the distal aspect of the mandibular second molar (M2) following third molar (M3) removal? STUDY DESIGN: To identify relevant articles for review, we completed a computerized literature search of Medline. The inclusion criteria for articles included prospective cohort studies or randomized clinical trials with follow-up periods of 6 months or more, and preoperative and postoperative measurements of periodontal probing depths (PDs) or attachment levels (ALs). RESULTS: Eight articles met the inclusion criteria. Overall, the reported mean changes in ALs or PDs on the distal of M2 6 months after M3 removal were clinically insignificant, ie, less than 2 mm. Six months after M3 removal, 52% to 100% of subjects had no change or improvement in ALs or PDs. Given periodontal disease present preoperatively, the number needed to treat (NNT) ranged from 3 to 10. Given healthy periodontal status preoperatively, 48% had worsening of their periodontal measures after M3 removal and the number needed to harm (NNH) was 2. CONCLUSION: Commonly, the second molar periodontal probing depth or attachment levels either remain unchanged or improve after third molar removal. For subjects with healthy second molar periodontium preoperatively, the indication for third molar removal needs to be evaluated carefully as these subjects have an increased risk for worsening of probing depths or attachment levels after third molar removal.

Alveolar Bone Loss↗
PubMed2003

Threshold estimates and superthreshold behavior of ultrasound-induced lung hemorrhage in adult rats: role of pulse duration.

The study objective was to estimate the pressure threshold (ED(05), effective dose, or in situ peak rarefactional pressure associated with 5% probability of lesions) of ultrasound (US)-induced lung hemorrhage as a function of pulse duration (PD) in adult rats. A total of 220 10- to 11-week-old 250-g female Sprague-Dawley rats (Harlan) were randomly divided into 20 ultrasonic exposure groups (10 rats/group) and one sham group (20 rats). The 20 ultrasonic exposure groups (2.8-MHz; 10-s exposure duration; 1-kHz PRF; -6-dB pulse-echo focal beam width of 470 microm) were divided into four PD groups (1.3, 4.4, 8.2 and 11.6 micros) and, for each PD group, there were five in situ peak rarefactional pressures (range between 4 and 9 MPa). Rats were weighed, anesthetized, depilated, exposed, and euthanized under anesthesia. The left lung was removed and scored for the occurrence of hemorrhage. If hemorrhage was present, the lesion surface area and depth were measured. Individuals involved in animal handling, exposure and lesion scoring were "blinded" to the exposure conditions. Logistic regression analysis was used to examine the dependence of the lesion occurrences, and Gaussian tobit regression analysis was used to examine the dependence of the lesion surface areas and depths on in situ peak rarefactional pressure and PD. Threshold results are reported in terms of ED(05). For PDs of 1.3, 4.4, 8.2 and 11.6 micros, respectively, lesion occurrence ED(05)s were 3.1, 2.8, 2.3 and 2.0 MPa with standard errors around 0.6 MPa. Lesion size ED(05)s showed similar values. A mechanical index (MI) of 1.9, the US Food and Drug Administration (FDA) regulatory limit of diagnostic US equipment, is equivalent to the adult rat's in situ peak rarefactional pressure of 4.0 MPa. PDs of 8.2 and 11.6 micros had ED(05)s more than 2 standard errors below 4.0 MPa, indicating that the ED(05)s of these two PDs are statistically significantly different from 4.0 MPa. The ED(05) threshold levels for a PD of 1.3 micros are consistent with previous US-induced lung hemorrhage studies. As the PD increases, the ED(05) levels decrease, suggesting greater likelihood of lung damage as the PD increases. All of the ED(05)s are less than the FDA limit.

Animals↗
PubMed2002

Prevalence and prognostic significance of psychiatric disorders in patients evaluated for recurrent unexplained syncope.

We aimed to assess the psychiatric profile and prognostic value of psychiatric disorders (PDs) in patients presenting with unexplained syncope. Forty patients with recurrent unexplained syncope referred for head-up tilt testing were compared with age- and sex-matched patients free of known chronic PDs referred for arrhythmia. All patients underwent a semistandardized psychiatry questionnaire (Mini-International Neuropsychiatric Interview) to assess their profile. Additional stress coping was performed to study adaptational processes to stressful situations. After tilt testing and psychiatric evaluation, a drug-free follow-up was performed in patients with syncope. Of the 80 patients who referred to the psychiatric interview, 40 had evidence of at least 1 psychiatric disorder. They were 26 patients (65%) in the syncope group and 14 patients (35%) in the control group (p = 0.01). Detailed analysis revealed a more frequent subprofile of anxiety and panic disorders in patients with syncope than in controls (30% vs 12% and 20% vs 10%, respectively), whereas the subprofile of depression was similar in both groups. Moreover, those with syncope were more likely to have a high anxiety index (25 +/- 5 vs 22 +/- 4, p = 0.004), and were more prone to avoidance-oriented coping strategies when experiencing undesirable life events than controls. Considering syncope patients, no difference could be found between the 25 with a positive tilt test and the 15 with a negative tilt test with respect to the number of syncopal episodes and psychiatric profile. After a 3-year drug-free follow-up, 15 patients (37.5%) had at least 1 recurrent syncope. The recurrence rate was similar in patients with positive and negative head-up tilt test results (9 of 25 vs 6 of 15, respectively). In contrast, the syncopal recurrence rate was higher in patients who fulfilled criteria for affective disorders (13 of 26 vs 2 of 14, 95% confidence interval 1.09 to 2.55, relative risk 1.7, p = 0.04). Thus, patients with recurrent unexplained syncope are more anxious and are more prone to panic disorders and avoidance-oriented coping strategies than control patients with arrhythmia. The presence of a psychiatric disorder is associated with an increased risk of recurrence. The outcome of such patients may be improved with recognition and treatment of PDs.

Adaptation, Psychological↗
PubMed2001

Pigmentary dispersion syndrome induced by a posterior chamber phakic refractive lens.

PURPOSE: To report a case of bilateral pigmentary dispersion syndrome (PDS) induced by the implantation of posterior chamber phakic refractive lenses (PRLs). METHOD: Case report. RESULTS: Following bilateral implantation of posterior chamber phakic refractive lenses in 38-year-old woman, unilateral elevated intraocular pressure (IOP) developed within months that was attributable to pigment dispersion within the anterior chamber. Findings consistent with PDS included bilateral transillumination defects of the iris in areas contacting the anterior surface of the PRLs, pigment deposits on the anterior surface of the PRLs, Krukenberg spindles, and bilateral dense pigmentation of the trabecular meshwork. The patient's IOP is presently under control and she has not developed glaucomatous damage. CONCLUSIONS: The development of PDS in this case demonstrates that posterior chamber phakic refractive lenses can make contact with the posterior iris and induce pigment dispersion syndrome in susceptible patients.

Adult↗
PubMed2000

The effects of various organ preservation solutions on hepatocyte membrane potentials, intracellular calcium concentrations, and outcome following liver transplantation.

BACKGROUND: Hepatocyte membrane potential differences (PDs) may be altered by the preservation solutions used in liver transplantation. Such alterations could impact on the survival of the donor liver, extent of biochemical injury, and flux of important ionic compounds. The purpose of the present study was to document these outcomes in the presence of four different preservation solutions. METHODS: Livers of adult male Sprague-Dawley rats (N = 3 to 4 per group) were impaled with intracellular microelectrodes prior to and at various time periods for 6 hours following complete hepatic resection. Just prior to resection, each liver was perfused with preservation solutions associated with high (normal saline [NS]), moderate (Euro-Collins [EC]), and low (University of Wisconsin solution [UW]) risks of reperfusion injury. RESULTS: Baseline (in situ) PDs were similar in all groups (-37 +/- 4 mV, mean +/- SD). Ten minutes postresection, hepatic PDs were as follows: NS, -23.8 +/- 3.5 mV; EC, -11.4 +/- 0.4 mV; and UW, -8.7 +/- 0.3 mV (P <0.01 for all groups). Maximum depolarization occurred at 6 hours postresection (NS, -8.1 +/- 1.1 mV; EC, -7.7 +/- 1.3 mV; and UW, -8.6 +/- 1.0 mV). To determine whether these changes are of pathophysiologic importance, the NS solution was modified (addition of 0.1% ethanol) to achieve similar PD changes as those observed with UW. Liver transplants were then performed where the donor livers had been perfused and preserved for 6 hours with either NS or the modified NS (MNS) solution. Posttransplant (10 day) survival was 1 of 6 (17%) in the NS group and 4 of 6 (67%) in the MNS group (P <0.05). Regarding the effects of PD changes on ionic flux, intracellular calcium levels were documented for up to 4 hours by fluorescence video microscopy using Fura-2 in isolated hepatocytes exposed to NS, UW, and MNS solutions. Intracellular calcium levels were similar in all solutions at each time point studied. CONCLUSIONS: The results of this study indicate that hepatocytes undergo prompt and marked depolarization following hepatic resection, and the extent of the depolarization correlates with survival following transplantation.

Adenosine↗
PubMed2003

A study of career choice patterns among Canadian medical students.

BACKGROUND: The number of students pursuing general surgery (GS) has declined in Canada. The reasons for this, and program directors' (PDs) perception of it, are unclear. METHODS: A survey was distributed to medical students at Queen's University and the University of Manitoba, and to all Canadian GS program directors to explore causes for the trend and identify potential solutions. RESULTS: Students pursuing GS were more likely to feel that GS fit their lifestyle needs (P < 0.05) and to have met positive role models (P < 0.05). Hardship of the training and practice, length of training, need for prestige, income and enjoyment of procedures did not correlate with specialty choice. Half of GS PDs did not perceive a decline in the number of applicants. CONCLUSIONS: Attention to student-raised concerns regarding GS programs and increased awareness of the applicants' trends among PDs can be used to address the current decline in applications to GS.

Adult↗