RESUMO
We have been investigating the effects of a synthetic immunostimulative polymer known as copovithane (Cpv). This agent appears to enhance humoral immunity in untreated and cyclosporine-immunosuppressed mice and is nontoxic in rodents and man. The purpose of this study was to determine whether cyclosporine (CsA) is deleterious to survival in a murine cecal ligation, puncture, and excision (CLPE) model of fecal peritonitis, and--if so--whether this effect could be ameliorated by Cpv without interfering with skin allograft acceptance. Cpv significantly prolongs survival in the CLPE model; the optimal dose for this effect was found to be 100 mg/kg. CsA was found to have a significant and deleterious effect on survival at several dosage levels when administrated 48 and 24 hr before cecal ligation, and immediately before and 16 hr after cecal ligation. Using a dose of CsA sufficient for skin allograft acceptance and the same schedule of administration outlined above, Cpv 100 mg/kg was administered 48 hr prior to cecal ligation. Mice treated with CsA plus Cpv had significantly longer survival than mice treated with CsA alone; furthermore, the survival of CsA-plus-Cpv-treated animals was not significantly different from that of saline-treated controls. Acceptance and survival of H-2 incompatible skin allografts in mice treated with CsA were not affected by Cpv 100 mg/kg/week. We conclude that CsA-induced mortality in the CLPE model can be abrogated by Cpv without adversely affecting skin allograft survival. It may eventually be possible to reduce the incidence of septic complications in clinical allotransplantation by prophylactically administering Cpv to patients on CsA immunosuppression.
Assuntos
Carbamatos/farmacologia , Ciclosporinas/efeitos adversos , Peritonite/induzido quimicamente , Povidona/farmacologia , Animais , Ciclosporinas/administração & dosagem , Sobrevivência de Enxerto/efeitos dos fármacos , Ligadura , Masculino , Camundongos , Camundongos Endogâmicos CBA , Transplante de Pele , Fatores de TempoRESUMO
The effect of the new immunosuppressant cyclosporine on survival after total small intestinal allotransplantation (TSIA) was studied in a canine model. Successful TSIA was performed in 34 dogs. Eleven dogs were treated with cyclosporine, 25 mg/kg/day i.m., starting the day before the operation and continuing for four weeks. Thereafter the same dose was given orally. Thirteen dogs were given oral cyclosporine only, 25 mg/kg/day from the day after transplantation. Ten dogs served as controls. The dogs treated with intramuscular and oral cyclosporine survived a mean of 103.8 +/- 39.4 days (mean +/- S.E.M.). The longest survivor died after 432 days. Survival in this group was significantly longer than that of the control dogs, which survived 12.5 +/- 4.6 days. The orally treated dogs survived 30.4 +/- 7.6 days. All control dogs, and seven of the orally treated dogs, but only two of the intramuscularly treated dogs, died of acute rejection. It is concluded that cyclosporine is effective in prolonging survival after TSIA in the dog and reduces the incidence of acute rejection.
Assuntos
Ciclosporinas/farmacologia , Sobrevivência de Enxerto/efeitos dos fármacos , Intestino Delgado/transplante , Animais , Ciclosporinas/uso terapêutico , Cães , Doença Enxerto-Hospedeiro/prevenção & controle , Terapia de Imunossupressão , Complicações Pós-Operatórias/patologia , Fatores de TempoRESUMO
BACKGROUND: Internet discussion lists, also known as mailing lists, are subject-specific groups that are participated in and distributed by e-mail. Medical mailing lists have not been warmly received by the peer-reviewed medical literature. OBJECTIVE: To demonstrate the potential value of medical discussion lists on the Internet through a description of Surginet, the largest such mailing list dealing with general surgery, and a survey of its participants. Our hypothesis is that Internet discussion lists fill a unique niche in dissemination of medical information. DESIGN: A retrospective review of the electronic activities of one medical mailing list, and an e-mail questionnaire survey of its membership's demographics and practice patterns. PARTICIPANTS: Four hundred eighty-nine subscribers to Surginet from 46 countries. MAIN OUTCOME MEASURES: Electronic activity of the list, subscribers' demographics, and subscribers' perceptions concerning the list's activities and its value. RESULTS: Surginet currently has 489 subscribers from 46 countries. During 1997 an average of 12.5 messages per day and 375 per month were posted, all dealing with topics in general surgery. Completed questionnaires were received from 190 subscribers (39%), of which 93% are men and 73% are between the ages of 30 and 50 years practicing in 38 countries; 84% are practicing surgeons and 13% are surgical residents. Most (59%) are "passive" members who read, but do not actively participate in, the discussions. Improving knowledge base, interaction with other surgeons, and obtaining consults were the most common reasons given for list subscription. CONCLUSIONS: Groups such as Surginet fill a niche involving the free exchange of ideas, methods, and attitudes relevant to the current practice of general surgery, which is different from the way medical information is disseminated by published literature and organized medical meetings. There is a perception among list subscribers that this is a valuable and useful modality for continuing education.
Assuntos
Cirurgia Geral , Cooperação Internacional , Internet , Comunicação , Humanos , Inquéritos e QuestionáriosRESUMO
Six hundred seventy-eight deltopectoral flaps were raised in 604 patients, 125 of which were delayed and 215 of which were used in previously irradiated beds. The rate of major flap necrosis was 16.9 percent and the overall rate of complications, 51.4 percent. Delay in creating the deltopectoral flap had no influence on the risk of complications and necrosis, whereas the use of the flap in a previously irradiated bed was associated with a significantly increased risk of major flap necrosis. The least flap loss occurred when the deltopectoral flap was used without tubulation for skin coverage only. Complications and flap necrosis occurred most frequently when flaps were tubulated in a reversed manner or used for lining of major portions of or for total oropharyngeal and hypopharyngeal reconstruction. The deltopectoral flap remains a useful, reliable, and versatile regional flap that can be used alone or in combination with other flaps in selected circumstances for major head and neck reconstruction.
Assuntos
Neoplasias de Cabeça e Pescoço/cirurgia , Retalhos Cirúrgicos , Feminino , Humanos , Masculino , Músculos , Recidiva Local de Neoplasia/cirurgia , Músculos Peitorais , Estudos Retrospectivos , OmbroRESUMO
Acute and chronic nephrotoxicity directly attributable to cyclosporine (CyA) administration remains an obstacle to its successful use. The studies presented in this report characterize the cytoprotective properties of 16,16-dimethyl prostaglandin E2 in a lethal CyA-induced nephrotoxic rodent model. Wistar-Furth rats (200-250 g) receiving CyA alone (100 mg/kg/day) showed marked deterioration in renal function with severe histologic renal lesions and death of the majority of animals by day 7. The prostaglandin treated group (10/micrograms/kg/day) administered concomitantly with CyA demonstrated near normal renal function and histology by the eighth day after CyA discontinuation, and in a significant improvement in animal survival of 85% (p less than 0.001, n = at least 20 rats/group). These studies demonstrate a novel approach to a major problem with cyclosporine and should have exciting clinical potential.
Assuntos
Ciclosporinas/antagonistas & inibidores , Nefropatias/prevenção & controle , Prostaglandinas Sintéticas/farmacologia , Animais , Creatinina/sangue , Ciclosporinas/toxicidade , Rim/patologia , Nefropatias/induzido quimicamente , Nefropatias/patologia , Testes de Função Renal , Masculino , Prostaglandinas E Sintéticas/farmacologia , Ratos , Ratos Endogâmicos , Fatores de TempoRESUMO
Isolated injury to the extrahepatic biliary tree after blunt trauma is rare. The authors describe the case of a 17-year-old boy who suffered such an injury after falling over the handlebar of his motorcycle. Ultrasonography, computed tomography and abdominal paracentesis were used to make the diagnosis. At laparotomy there was a partial tear of the common bile duct at its junction with the cystic duct. A cholecystectomy was performed and a T tube inserted. The patient recovered without complication. The authors emphasize that only awareness of the condition and diagnostic confirmation by computed tomography and abdominal paracentesis can expedite the diagnosis and treatment. The choice of surgical repair must be individualized according to the clinical findings and the nature of the injury.
Assuntos
Ducto Colédoco/lesões , Ferimentos não Penetrantes , Adolescente , Ducto Colédoco/patologia , Ducto Cístico/lesões , Ducto Cístico/patologia , Humanos , Masculino , RupturaRESUMO
The proper teaching of operative skills to surgical residents is increasingly constrained by operative time, complex procedures and medicolegal concerns. A technical-skills program was developed and introduced over a 3-year period to 28 1st-year residents in general surgery. To introduce the residents to the principles of surgical techniques in a simulated environment outside the operating room, the program consisted of a combination of two didactic sessions and six "wet labs" taking 3 to 4 hours per week for 8 weeks between January and March each year. The didactic sessions included instruction on suture material and the use of stapling devices; the "wet lab" used a "hands-on" approach. Educational objectives in the "wet lab" included instruction on preparation of the patient and draping, aseptic technique, principles of bowel anastomosis, incisions, instrument use and handling, principles of hemostasis, intraoperative surgical emergencies, surgical assisting and overall conduct in the operating room. The residents' surgical technique and skills improved over the course period. The overall value, teaching and understanding of surgical principles were rated highly. Problems cited during resident feedback were the use of live animals and insufficient time to practise. The efficacy of a surgical-skills program has been demonstrated, but its effectiveness requires further evaluation.
Assuntos
Cirurgia Geral/educação , Internato e Residência , Canadá , Competência Clínica , CurrículoRESUMO
Pairs of mongrel dogs received orthotopic total small bowel allografts. Half were treated with the immunosuppressive agent cyclosporin A and the other half were not. Ten untreated dogs survived a mean of 12.5 days (range from 7 to 25 days). They lost up to 30% of their initial body weight and rejection with hemorrhagic necrosis was usually the cause of graft failure. The mean survival of 11 dogs treated with cyclosporin A was 90.6 days (range 9 to 286 days) with early deaths being due to pneumonia or volvulus. Intestinal mucosa appeared normal, but there was some smooth muscle hypertrophy. Reconnection of lymph vessels was complete in all dogs examined more than 21 days after allografting. Two dogs survived for 203 and 221 days, respectively, and one dog remains alive and well 287 days after operation. The long-term survivors remained healthy, with steady body weights, formed stools, normal plasma protein values and xylose absorption curves that did not differ from those of autografted dogs. Roentgenography after a barium meal and follow-through study showed normal mucosa. The transit time was around 60 minutes (normal 150 minutes). Late, acute episodes of rejection occurred in two dogs, when blood levels of cyclosporin A were low (less than 400 ng/ml). Bowel mucosa showed ulceration and villous atrophy, with lymphoid infiltration, leading to malabsorption as a terminal event. Cyclosporin A is effective in increasing the duration of survival in dogs with small bowel allografts while maintaining essentially normal bowel structure and good function.
Assuntos
Ciclosporinas/uso terapêutico , Intestino Delgado/transplante , Animais , Cães , Rejeição de Enxerto , Intestino Delgado/patologia , MortalidadeRESUMO
In two patients who had peritoneovenous shunts inserted for the treatment of intractable ascites, the shunt became infected following dental procedures that were carried out without antibiotic prophylaxis. The organisms grown were alpha-hemolytic streptococcus in one patient, and alpha-hemolytic streptococcus and Klebsiella pneumoniae in the other. Alpha hemolytic streptococcus is commonly found in the oral cavity and has also been found, related to dental manipulations, in hematogenous infections at other sites. In both patients the infections were successfully managed by antibiotic treatment with removal of the infected shunt. Physicians caring for patients with peritoneovenous shunts should be aware of this potential complication; antibiotics should always be given prophylactically at the time of dental procedures.
Assuntos
Capeamento da Polpa Dentária/efeitos adversos , Infecções por Klebsiella/transmissão , Derivação Peritoneovenosa , Infecções Estreptocócicas/transmissão , Extração Dentária/efeitos adversos , Procedimentos Cirúrgicos Vasculares , Adulto , Ascite/cirurgia , Doença Crônica , Humanos , Klebsiella pneumoniae , Masculino , Pessoa de Meia-Idade , Complicações Pós-OperatóriasRESUMO
We electively compared the distal splenorenal ("selective") shunt with the end-to-side portacaval shunt in 80 prospectively randomized patients with variceal bleeding. Selective shunts required more operative time (3.9 vs. 2.8 h) and blood replacement (4.6 vs. 2.5 U) and postoperative mortality was slightly higher (5 of 38 selective vs. 0 of 40 portacaval). Postoperative complication rates were similar. After 65-mo mean follow-up, both shunts have protected well against late gastrointestinal bleeding (5 selective, 4 portacaval episodes). However, after selective shunts, spontaneous encephalopathy occurred less often (23% vs. 40% of patients), was severe in fewer patients (12% vs. 33%), and precipitated fewer hospital admissions (6 admissions in 4 selective patients vs. 26 admissions in 13 portacaval patients). Furthermore, selective shunt patients remained longer without functional disability (83% vs. 70% of postoperative patient months). Long-term survival was not significantly different in the two groups (5-yr survival: selective 51%, portacaval 56%).
Assuntos
Encefalopatias/etiologia , Hepatopatias/cirurgia , Derivação Portocava Cirúrgica/efeitos adversos , Derivação Portossistêmica Cirúrgica/efeitos adversos , Derivação Esplenorrenal Cirúrgica/efeitos adversos , Adulto , Idoso , Ensaios Clínicos como Assunto , Varizes Esofágicas e Gástricas/cirurgia , Feminino , Humanos , Hepatopatias/mortalidade , Masculino , Pessoa de Meia-Idade , Derivação Portocava Cirúrgica/mortalidade , Estudos Prospectivos , Qualidade de Vida , Distribuição Aleatória , Derivação Esplenorrenal Cirúrgica/mortalidadeRESUMO
The authors report on 178 patients with unresectable hepatic tumors who have been treated with 1 to 25 (median, 6) courses of radiofrequency hyperthermia (RFHT) and chemotherapy. In 137 patients, the hepatic tumors consisted of metastases from colorectal adenocarcinomas. For patients who had no previous therapy and who had colorectal metastases with no extraheptic disease, cumulative survival at 52 weeks' follow-up was 80.5% and partial tumor regression was seen in 78.4%. Among the 69 patients who previously had conventional treatment for their hepatic disease, partial regression was seen in 43.5%. We are no longer monitoring tumor core temperature routinely, as the invasive methods currently in use yield irreproducible results; the risks to the patient cannot be justified in view of the questionable relevance of the data obtained. A prospective randomized study of systemic chemotherapy with or without RFHT in patients with colorectal hepatic metastases is in progress.
Assuntos
Adenocarcinoma/terapia , Antineoplásicos/uso terapêutico , Temperatura Alta/uso terapêutico , Neoplasias Hepáticas/terapia , Ondas de Rádio , Adenocarcinoma/secundário , Adulto , Idoso , Temperatura Corporal , Terapia Combinada , Feminino , Febre/etiologia , Temperatura Alta/efeitos adversos , Humanos , Neoplasias Hepáticas/secundário , Masculino , Metronidazol/uso terapêutico , Pessoa de Meia-Idade , Peritonite/etiologia , PrognósticoRESUMO
Local recurrence after radical surgery is a major problem with many primary solid cancers. The use of radiofrequency hyperthermia (RFHT) as adjuvant therapy to surgery was explored in the Fischer bladder carcinoma (FBCa)/F344 rat tumor system. After subcutaneous innoculation of 34 rats with 10(6) FBCa cells in suspension, RFHT was administered to 17 animals on days 1, 5, 8, and 12. The development of palpable tumors was delayed but not prevented, and tumor growth was retarded in RFHT-treated animals. In another experiment 40 rats were innoculated by subcutaneous trocar injection with a 1 mm3 piece of FBCa. After tumor excision on day 17, adjuvant therapy (untreated control, mitomycin C, RFHT, or RFHT plus mitomycin C) was started on day 20 (10 rats/treatment). The 20 RFHT-treated rats had only 1 incisional recurrence as compared to 9 recurrences in sham-heated rats (P less than 0.005). The authors conclude that RFHT has considerable value as adjuvant therapy to surgery in these tumors. Additional studies of RFHT as adjuvant treatment after surgical excision of tumors are planned.