RESUMEN
We determined the effect of pelvic organ decentralization and reinnervation 1 yr later on urinary bladder histology and function. Nineteen canines underwent decentralization by bilateral transection of all coccygeal and sacral (S) spinal roots, dorsal roots of lumbar (L)7, and hypogastric nerves. After exclusions, eight were reinnervated 12 mo postdecentralization with obturator-to-pelvic and sciatic-to-pudendal nerve transfers, then euthanized 8-12 mo later. Four served as long-term decentralized only animals. Before euthanasia, pelvic or transferred nerves and L1-S3 spinal roots were stimulated and maximum detrusor pressure (MDP) recorded. Bladder specimens were collected for histological and ex vivo smooth muscle contractility studies. Both reinnervated and decentralized animals showed less or denuded urothelium, fewer intramural ganglia, and more inflammation and collagen, than controls, although percent muscle was maintained. In reinnervated animals, pgp9.5+ axon density was higher compared with decentralized animals. Ex vivo smooth muscle contractions in response to KCl correlated positively with submucosal inflammation, detrusor muscle thickness, and pgp9.5+ axon density. In vivo, reinnervated animals showed higher MDP after stimulation of L1-L6 roots compared with their transected L7-S3 roots, and reinnervated and decentralized animals showed lower MDP than controls after stimulation of nerves (due likely to fibrotic nerve encapsulation). MDP correlated negatively with detrusor collagen and inflammation, and positively with pgp9.5+ axon density and intramural ganglia numbers. These results demonstrate that bladder function can be improved by transfer of obturator nerves to pelvic nerves at 1 yr after decentralization, although the fibrosis and inflammation that developed were associated with decreased contractile function.
Asunto(s)
Músculo Liso/fisiopatología , Transferencia de Nervios , Traumatismos de la Médula Espinal/fisiopatología , Nervios Espinales/fisiopatología , Vejiga Urinaria/inervación , Animales , Perros , Estimulación Eléctrica/métodos , Contracción Muscular/fisiología , Regeneración Nerviosa/fisiología , Transferencia de Nervios/métodos , Raíces Nerviosas Espinales/fisiopatología , Vejiga Urinaria/fisiopatologíaRESUMEN
This study determined the effect of pelvic organ decentralization and reinnervation 1 yr later on the contribution of muscarinic and purinergic receptors to ex vivo, nerve-evoked, bladder smooth muscle contractions. Nineteen canines underwent decentralization by bilateral transection of all coccygeal and sacral (S) spinal roots, dorsal roots of lumbar (L)7, and hypogastric nerves. After exclusions, 8 were reinnervated 12 mo postdecentralization with obturator-to-pelvic and sciatic-to-pudendal nerve transfers then euthanized 8-12 mo later. Four served as long-term decentralized only animals. Controls included six sham-operated and three unoperated animals. Detrusor muscle was assessed for contractile responses to potassium chloride (KCl) and electric field stimulation (EFS) before and after purinergic receptor desensitization with α, ß-methylene adenosine triphosphate (α,ß-mATP), muscarinic receptor antagonism with atropine, or sodium channel blockade with tetrodotoxin. Atropine inhibition of EFS-induced contractions increased in decentralized and reinnervated animals compared with controls. Maximal contractile responses to α,ß-mATP did not differ between groups. In strips from decentralized and reinnervated animals, the contractile response to EFS was enhanced at lower frequencies compared with normal controls. The observation of increased blockade of nerve-evoked contractions by muscarinic antagonist with no change in responsiveness to purinergic agonist suggests either decreased ATP release or increased ecto-ATPase activity in detrusor muscle as a consequence of the long-term decentralization. The reduction in the frequency required to produce maximum contraction following decentralization may be due to enhanced nerve sensitivity to EFS or a change in the effectiveness of the neurotransmission.
Asunto(s)
Neuronas Motoras/efectos de los fármacos , Contracción Muscular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Vejiga Urinaria/fisiología , Adenosina Trifosfato/farmacología , Animales , Atropina/farmacología , Estimulación Eléctrica/métodos , Antagonistas Muscarínicos/farmacología , Contracción Muscular/fisiología , Músculo Liso/fisiología , Transferencia de Nervios/métodos , Vejiga Urinaria/efectos de los fármacos , Vejiga Urinaria/inervaciónRESUMEN
The testicular dysgenesis syndrome (TDS) hypothesis, which proposes that common reproductive disorders of newborn and adult human males may have a common fetal origin, is largely untested. We tested this hypothesis using a rat model involving gestational exposure to dibutyl phthalate (DBP), which suppresses testosterone production by the fetal testis. We evaluated if induction of TDS via testosterone suppression is restricted to the "masculinization programming window" (MPW), as indicated by reduction in anogenital distance (AGD). We show that DBP suppresses fetal testosterone equally during and after the MPW, but only DBP exposure in the MPW causes reduced AGD, focal testicular dysgenesis, and TDS disorders (cryptorchidism, hypospadias, reduced adult testis size, and compensated adult Leydig cell failure). Focal testicular dysgenesis, reduced size of adult male reproductive organs, and TDS disorders and their severity were all strongly associated with reduced AGD. We related our findings to human TDS cases by demonstrating similar focal dysgenetic changes in testes of men with preinvasive germ cell neoplasia (GCNIS) and in testes of DBP-MPW animals. If our results are translatable to humans, they suggest that identification of potential causes of human TDS disorders should focus on exposures during a human MPW equivalent, especially if negatively associated with offspring AGD.
Asunto(s)
Disgenesia Gonadal/inducido químicamente , Enfermedades Testiculares/inducido químicamente , Animales , Dibutil Ftalato/toxicidad , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Exposición Materna , Plastificantes/toxicidad , RatasRESUMEN
INTRODUCTION: Professionalism is now recognized as a core competency of surgical education and is required for certification and licensure. However, best teaching methods remain elusive, because (1) ethical standards are not absolute, and (2) learning and teaching styles vary considerably-both of which are influenced by cultural and generational forces. We sought to compare attitudes, knowledge, and behaviors in fourth year medical students, compared to surgeons in training and practice, focusing on issues related to professionalism in plastic surgery. METHODS: Fourth year medical students participating in a capstone course (n = 160), surgical residents (n = 219), and attending surgeons (n = 99) at a single institution were asked to complete a questionnaire regarding surgical professionalism. Participants (1) identified components of professionalism, (2) cited examples of unprofessional behavior, (3) ranked the egregiousness of 30 scenarios, and (4) indicated best educational practices. Cohorts were compared using t test and χ, with statistical significance assigned to P values less than 0.05. RESULTS: Compared to surgeons in training or practice, medical students were younger (27.8 vs 38.0 years, P < 0.001) and more often female (51.1% vs 36.6%, P < 0.03). Both groups cited "a body of ethics" as the defining component of professionalism. Respondents from both groups agreed that professionalism could be taught, learned, and assessed. Surgeons (94.3%) had observed unprofessional behavior, as did 88.0% of students; "poor anger management," "dishonesty," and "bullying" were the most common examples. Compared to students, however, surgeons were more likely to witness substance and physical abuse (P < 0.05). From the list of 30 scenarios, both groups picked the following as the most egregious, although in different order: working while impaired, fraudulent billing, dating a patient, lying on rounds, self-prescribing, and sexual harassment. Both students and surgeons agreed that the following scenarios were unethical: "fraudulent billing while on a mission trip" (84% vs 90%, NS), "showing inaccurate preop/postop photos" (70% vs 75%, NS), and "failing to disclose a conflict of interest" (56% vs 57%). Students and surgeons disagreed that the following scenarios were egregious: "owning biotech stock in a company whose product the surgeon uses" (33% vs 13%, P < 0.01), and "offering a breast augmentation as part of a charity raffle" (45% vs 58%, P < 0.05). Both students and surgeons agreed "advertising on a highway billboard was NOT unprofessional (87% vs 85%, NS). CONCLUSIONS: Despite differences in age and sex, medical students and surgeons have similar attitudes about professionalism in plastic surgery, but differ in their knowledge and observations. Understanding cultural and generational factors may help educators teach and model cognitive and behavioral aspects of professionalism. The fact that some clearly egregious behaviors are not viewed as unethical by individual students, trainees, and surgeons, and that such behavior continues to be observed, indicates the need to improve our efforts in promoting professionalism in plastic surgery.
Asunto(s)
Actitud del Personal de Salud , Internado y Residencia/ética , Profesionalismo , Estudiantes de Medicina , Cirujanos/ética , Cirugía Plástica/ética , Adulto , Femenino , Humanos , Masculino , Sudeste de Estados Unidos , Estudiantes de Medicina/psicología , Cirujanos/psicología , Cirugía Plástica/educación , Cirugía Plástica/psicología , Encuestas y CuestionariosRESUMEN
PURPOSE: To elucidate the components of professionalism specific to plastic surgery, we surveyed surgeons, anesthesiologists, and fourth-year medical students at a public university. We sought to define the central components of professionalism in plastic surgery, to determine the difference in perception of professionalism by plastic surgeons (PSs), compared to other practitioners (OPs), and to improve education in professionalism by obtaining data on attitudes of professionalism among practitioners. METHODS: Using SurveyMonkey, we distributed a questionnaire to members of the Departments of Surgery and Anesthesia and fourth-year medical students. The responses of PSs (n = 22) were compared to non-plastic surgeons (OPs, n = 294). RESULTS: Of the 594 participants, 316 completed the survey (response rate, 53%). Participants consisted of 211 (66.8%) medical students, 60 (19%) residents, 5 (1.6%) fellows, 28 (8.9%) attending physicians, 6 (1.9%) nonphysician providers, and 6 (1.9%) administrators. Both PS and OP listed "the development and conformance to a body of ethics" the most important component of professionalism. Most participants thought that professionalism could be taught, and assessed. Plastic surgeons listed "not enough mentors" (63.2%) as the main obstacle to teaching professionalism, whereas OP listed "not a priority in medical school curriculum" (48.2%). Both PS and OP cited substance abuse, fraud, and sexual misconduct as egregious displays of unprofessional behavior. Opinions differed between the groups, regarding aspects of professionalism pertaining to plastic surgery. When asked about "charity raffles" for cosmetic surgery, 72.2% of PS ranked this as a 4 or 5 (with 5 representing the most unprofessional behavior), compared to only 46.7% of OP who assigned this a 4 or 5. For the scenario of a PS deceiving patients, by showing them another surgeon's before and after photographs, 84.2% of PS assigned this a 4 or 5, whereas 71.0% of OP ranked this a 4 or 5. Both groups cited working while impaired with alcohol as the most egregious example of unprofessional behavior. CONCLUSIONS: The opinions of PSs mirror those of their colleagues, regarding general components of professionalism. However, PSs are more conservative and cautious than their peers, perhaps due to successful educational efforts in mentoring, training, and maintenance of certification.