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Background Exercise-induced stress induces considerable changes in the immune system. To better understand the mechanisms related to these immune changes during acute and chronic physical stress, we studied the effects of aerobic physical training (APT) on several parameters of the immune system. Methods Previously untrained males (18-25 years of age) were divided into a group that was subjected to 6 months of APT (N.=10) and a sedentary control group (N.=7). The subjects performed a cardiopulmonary exercise test (CET) at 0, 3, and 6 months of the APT program. B cell (CD19+), T cell (CD4+ and CD8+), and natural killer cell (CD56+) levels, and mitogen-induced T cell proliferation and cytokine production (interleukin-1, interleukin-4, interleukin-12, and interferon-γ) were evaluated before and at 30 seconds and 24 hours after the CET. Results There was a significant increase in CD4+ T cells and natural killer cells and a significant reduction in T cell proliferation in both groups 30 seconds after the CET at 0, 3 and 6 months of the APT program. Of note, the trained group showed significantly lower resting T cell proliferation (before and 24 hour after the CET) than the sedentary control groups at 0, 3 and 6 months of the APT program. There were no significant differences in cytokine production after the CET between both groups at any time point of the APT program. Conclusions These data show that APT does not condition against strenuous exercise-induced immune changes but significantly modulates T cell proliferative responses.

Objective Augmented reality (AR) is a technique in which an overlay of a virtual image to a live picture is performed to create a new image in which both original images coexist as a single image. This results in the visualization of internal structures through overlying tissues. The objective was to describe an easy, inexpensive, and successful method to coregister with AR in an image-guided surgery setting using the resources at hand. Methods Cortical information was obtained with a volumetric acquisition of 200 0.8-mm thick, cerebral magnetic resonance imaging scans in an axial T1-weighted sequence. For the venous anatomy, a contrast phase at 7 mm/s velocity was used. This data was reconstructed in a three-dimensional fashion using MRIcro software (v. 1.37, freeware, courtesy of Chris Rorden) and was overlaid to a digital image of the cerebral cortex either pre- or intraoperatively. Results Eight patients were studied. There was an adequate coregistration in seven of the patients as confirmed by intraoperative ultrasound, frame-based stereotaxy, or obvious anatomic homology between the three-dimensional magnetic resonance imaging scan virtual reconstruction and the live image obtained during surgery. AR was not possible in one case of a cerebellar lesion. Conclusion AR coregistration capabilities are adequate when revised by other intraoperative guidance devices. When performed with "freeware" software and conventional digital cameras, it is relatively inexpensive, which makes it a potential tool for surgical planning and noncontinuous intraoperative guidance in neurosurgery. Its largest drawbacks are the inability to function in deep-seated lesions and its lack of tracking devices, which gives it a noncontinuous coregistration nature.

In this clinical study, five consecutive referrals to a cognitive rehabilitation therapy (CRT) programme were followed in a longitudinal protocol involving a resting SPECT and neuropsychological evaluation at pre-treatment, post-treatment, and post non-treatment intervals. All clients had acquired brain injury and initially demonstrated neuropsychological deficits and various degrees of hypoperfusion on SPECT. Statistical Parametric Mapping (SPM) was used to evaluate change in successive SPECT images. Following CRT, all clients were able to return to productive employment or schooling. Examination of the neuropsychological testing results revealed significant improvement in performance following CRT which were generally maintained during the non-treatment period. SPM analysis of the SPECT data revealed that, in a majority of cases, most of the significant increases in relative cerebral blood flow redistribution were seen during the treatment period, rather than the non-treatment period. The results suggest that, even in individuals who are more than 2 years post-brain damage, relative increases in rCBF can be demonstrated following individualized CRT and that most of these changes can be related to improvements on neuropsychological tests.

The efficacy and safety of two polyvalent horse-derived antivenoms in Bothrops asper envenomings were tested in a randomized, double-blind, clinical trial performed in Colombia. Both antivenoms were manufactured from the same pool of hyperimmune plasma. Antivenom A was made of F(ab')2 fragments, generated by pepsin digestion and caprylic acid precipitation, whereas antivenom B consisted of whole IgG molecules produced by caprylic acid precipitation followed by ion-exchange chromatography. Besides the different nature of the active substance, antivenom B had higher protein concentration, slightly higher turbidity and aggregate content. No significant differences were observed in the efficacy of antivenoms. Both halted local and systemic bleeding (P = 0.40) within 6-12 h of treatment in 100% of the cases, and restored blood coagulation (P = 0.87) within 6-24 h in 84.7% of patients, and within 48 h in all of them, in agreement with restoration of plasma fibrinogen concentration. Venom concentrations in serum dropped significantly (P < 0.001), to very low levels, 1 h after antivenom infusion. Nevertheless, eight patients (11.1%), four for each antivenom, presented recurrence of venom antigenaemia at different times, from 6 to 96 h, with clinical significance (recurrent coagulopathy) only in one group B patient (2.9%). Serum creatine kinase (CK) activity was increased, as a consequence of local myonecrosis. There was no significant difference (P = 0.51) in the incidence of early adverse reactions to antivenom administration (28.9% for patients of group A and 20.6% for patients of group B), most of the reactions being mild, mainly cutaneous. The most frequent complications were cellulitis (16.7%), abscess formation (5.6%), acute renal failure (8.3%), and compartmental syndrome (5.6%). In conclusion, IgG and F(ab')2 antivenoms, prepared by caprylic acid fractionation, presented similar efficacy and safety profiles for the treatment of B. asper envenomings in Colombia.

Orthopedic reductions are commonly performed procedures requiring sedation in the pediatric emergency department (PED). Ketamine is a widely used agent for pediatric procedural sedation, but its use may present difficulties in select populations, such as those with psychiatric diagnoses. In such a case, alternative agents that are safe and effective are needed. Etomidate is a commonly used induction agent for rapid-sequence intubation in the PED. Several retrospective and few prospective studies support etomidate's safety and efficacy in pediatric procedural sedation.The objective was to compare etomidate/fentanyl (E/F) with ketamine/midazolam (K/M) for procedural sedation during orthopedic reductions in the PED.Prospective, partially blinded, randomized controlled study comparing intravenously administered K/M with intravenously administered E/F. A convenience sample of patients, aged 5 to 18 years, presenting to an urban PED with fracture requiring reduction was enrolled. Outcome measures included guardian and staff completion of visual analog scale and Likert scales for observed pain and satisfaction, blinded OSBD-r (Observational Scale of Behavioral Distress-Revised) scoring of digital recordings of reductions, and sedation and recovery times. Descriptive tracking of adverse effects, adverse events, and interventions were recorded at the sedation.Twenty-three patients were enrolled, 11 in the K/M group and 12 in the E/F group. The K/M group had significantly lower mean OSBD-r scores compared with the E/F group (0.08 vs 0.89, P = 0.001). Parents rated lower visual analog scale scores with K/M than with E/F (13.7 vs 50.5, P = 0.003) and favored K/M on a 5-point satisfaction scale (P = 0.004). The E/F group had significantly shorter total sedation times (49.6 vs 77.6 minutes, P = 0.003) and recovery times (24.7 vs 61.4 minutes, P = 0.000). There were no significant differences with respect to procedural amnesia and orthopedic practitioner satisfaction. Adverse effects noted in the K/M group included dysphoric emergence reaction and vomiting. Vomiting, injection-site pain, myoclonus, airway readjustment, and supplemental oxygen use were observed in the E/F group.This is a small study that strongly suggests that, for pediatric orthopedic reductions, K/M is more effective at reducing observed distress than E/F, although both provide equal procedural amnesia. With its significantly shorter sedation and recovery times, E/F may be more applicable for procedural sedation for shorter, simpler procedures in the PED.

To evaluate the accuracy of a previously proposed prognostic index of mortality determined by nutritional indicators in patients severe acute pancreatitis. Methods (study population, subjects, intervention): We evaluated used three nutritional status indicators (total lymphocyte count, creatinine/height index and subescapular skinfold) to determine an index associated to mortality prognosis in patients with severe acute pancreatitis.We assessed 34 patients, who were divided according to their outcome into: a) survivor, b) dead. The vast majority showed a litiasic origin of the disease, which was present among men, predominantly. The index' results were found to be directly (positively) related to mortality probability, i.e., the closer the score was to 2,the more probability the patient had to die.Even though we were able to prove association between the proposed index and the patient's prognosis, a larger sample is needed to validate this as a possible tool which could be used along other prognostic test such as APACHE II or Ranson scales.

Scorpion stings are a public health problem in many countries. However, in Colombia, very few epidemiological, clinical or toxicological studies have been undertaken.Ecological and epidemiological aspects were related to the prevalence of scorpion stings by Tityus asthenes. The clinical features of envenomization were described in patients and in an experimental animal model.The study was conducted in four localities of Mutatá and Urabá Counties in the province of Antioquia, Colombia. The sample consisted of 1,593 (929 urban, 664 rural) of the 5,305 exposed people, inhabitating 324 households (188 urban (58%); 136 rural (42%) of 1,448 houses total in the study area. An interview survey was performed in every selected family for a more realistic estimate of sting prevalence. Additionally, a prospective study was directed toward patients presenting scorpion stings at care at the local hospital over an 18-month period.The probability was 12.9 times greater of finding T. asthenes inside or around houses in places near to forest and high agrarian plantations (odds ratio = 13). Eighty scorpion stings were reported in the retrospective study (4.1% prevalence [95% CI 3.3-4.8%] ), but only 14 of the patients (17.5%) sought care in the local hospital (an 82.5% underreportage). Seventy percent of the stings occurred in rural places; 50% occurred in the locality of Caucheras, with an attack rate of 10.6%. The overall household infestation rate was 269% (95% CI 22.9-30.8%) and an area dispersion ratio of 100%. Signs of systemic envenomization occurred mainly in children (67%). The 50% lethal dose of T. asthenes venom was 121.6 µg for 18-20 g Swiss Webster rats (95% CI 103.7-139.6). Immunodetection of T. asthenes and Centruroides gracilis/C.margantatus venoms in the experimental animals was possible when were tested by Western blot against Alacramyn (Instituto Bioclón, México) and Soro antiaracnídico (Instituto Butantan, Brasil) antivenoms. Scorpion interspecific differences were noted.The prevalence of stings by T. asthenes were common and their presence was associated with tropical rainforests. Envenomization at low density can be neutralized efficiently by anti-scorpion antivenoms produced in México and Brazil but with differing specificities for the venom of each scorpion species.

The correct interpretation of myocardial perfusion single photon emission computed tomography (SPECT) requires knowledge of the technique reproducibility. The objective was analyze the interobserver correlation of different experience in the interpretation of myocardial perfusion SPECT in patients following acute myocardial infarction (AMI) in order to improve the quality of our site.Sixty cases (56 +/- 11 years, 87 % men) with transmural AMI who had recently undergone successful thrombolysis were included. Resting perfusion with (99m)Tc-sestamibi was performed at one week post-AMI.Semiquantitative interpretation using 17 segment-model by 2 independent specialists and 5 observers, was performed blindly. Left ventricular ejection fraction (LVEF) was measured with isotopic ventriculography one month after AMI, with a mean of 38 %.Using independent and then agreed on perfusion analysis, average involved segments/patient was 9.3 +/- 4 and the sum of severity 25 +/- 13. Readings of other observers ranged from 7 +/- 3.7 to 9.4 +/- 3.9 and 16.7 +/- 9.7 to 24.6 +/- 13, respectively, consistent with the reading of the specialists of between 0.779-0.871 (kappa: 0.565-0.741). There was no significant difference when the number of segments were analyzed in 40 % of the cases and for intensity in 60 % of them in more experienced observers. Correlation with consensus reading for the number of segments ranged from 0.84 to 0.94 and for severity from 0.79 to 0.89. Identification of culprit arteries was acceptable, with r values between 0.612 and 0.683 and kappas between 0.629 and 0.656. Correlation of the number of involved segments and severity with LVEF performed one month after AMI was 0.73 and 0.74, respectively.There was good correlation in the interpretation of myocardial perfusion SPECT, with a significantly better fit in more experienced observers. This academic exercise was also helpful in improving our residents' skills in cardiology.

The efficacy and safety of two whole IgG polyvalent antivenoms (A and B) were compared in a randomised, blinded clinical trial in 67 patients systemically envenomed by Bothrops asper in Colombia. Both antivenoms were fractionated by caprylic acid precipitation and had similar neutralising potencies, protein concentrations and aggregate contents. Antivenom B was additionally treated with β-propiolactone to lower its anticomplementary activity. Analysing all treatment regimens together, there were no significant differences between the two antivenoms (A = 34 patients; B = 33 patients) in the time taken to reverse venom-induced bleeding and coagulopathy, to restore physiological fibrinogen concentrations and to clear serum venom antigenaemia. Blood coagulability was restored within 6–24 h in 97% of patients, all of whom had normal coagulation and plasma fibrinogen levels 48 h after the start of antivenom treatment. Two patients (3.0%) had recurrent coagulopathy and eight patients suffered recurrence of antigenaemia within 72 h of treatment. None of the dosage regimens of either antivenom used guaranteed resolution of venom-induced coagulopathy within 6 h, nor did they prevent recurrences. A further dose of antivenom at 6 h also did not guarantee resolution of coagulopathy within 12–24 h in all patients. The incidence of early adverse reactions (all mild) was similar for both antivenoms (15% and 24%; P > 0.05). Instituto Colombiano para el Desarrollo de la Ciencia y la Tecnología Francisco José de Caldas//COLCIENCIAS/Colombia Universidad de Antioquia/[206PI0281]/CYTED/Colombia Universidad de Costa Rica//UCR/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)

To determine clinical and epidemiological features of scorpion stings in two departments of Colombia, a descriptive study was performed in the hospitals of 10 towns from Antioquia (2 256 071 inhabitants) and five from Tolima (630 424 inhabitants). One hundred and twenty-nine cases were admitted during one year, 51 in Antioquia, 78 in Tolima and 41 were children less than 15 years old. Most stings (70.5%) occurred inside the house; 27.9% were on the hands and 26.4% on the feet. The scorpion species involved were Tityus pachyurus (51), Centruroides gracilis (31), T. fuehrmanni (29), T. asthenes (7) and Chactas spp. (1). In 10 cases the scorpion involved was not identified. Systemic envenoming signs (e.g. vomiting, tachypnea) were significantly more frequent in children than in adults (P < 0.05). Four children had hypertension, but none developed pulmonary oedema. One 3-year-old girl, stung by T. asthenes, had acute oedematous pancreatitis. Ninety-eight patients had mild envenoming. Moderate (27 patients) and severe (four patients) envenoming was significantly more frequent in children than in adults (P = 0.003; relative risk = 2.97). A pepsin-digested anti-Centruroides spp. antivenom was administered to 19 of 31 patients presenting systemic envenoming signs. No adverse reactions to antivenom were observed.

A silent, reversible myocardial ischemia with normal coronary angiography and reversible with thyroid hormone substitution, has been recently described in hypothyroid patients. We report a 49 years old male with an abnormal exercise electrocardiogram detected in a preventive medical examination. He had laboratory evidence of hypothyroidism and a history of two years of asthenia and progressive coarsening of the voice. The Thallium myocardial perfusion study, showed an alteration of coronary flow during exercise in the septum and lower wall of the left ventricle. Thyroid hormone substitution was started and three months later, a coronary angiography was normal. After six months a repeated Thallium perfusion study and exercise electrocardiogram were informed as normal.

Total parenteral nutrition (TPN) has been traditionally used as an adjunctive therapy in severe ulcerative colitis patients. We performed a prospective study to ascertain the safety, nutritional efficiency, tolerance and costs of total enteral nutrition in this situation.After 48 hours of intensive medical treatment, severe ulcerative colitis patients initiated enteral feeding with a polymeric formula. The formula concentration and volume were increased daily.17 patients (7 women, 10 men; age 36.8 +/- 12.8 years) with a mean clinical activity score of 15.6 +/- 1.5 were included. In 14 patients (82.4%) enteral nutrition was well tolerated, attaining in 11 of them more than 80% of the caloric requirements by day 4. In 3 cases we observed vomiting and bloating. Prealbumin levels improved significantly from 11.1 +/- 3.4 mg/dl to 22.7 +/- 6.8 mg/dl (p = 0.002) at the end of enteral nutrition (11.8 +/- 4.7 days). Albumin and other nutritional parameters did not change.Total enteral nutrition could be considered a safe and well tolerated nutritional support in these patients. Although albumin and other nutritional parameters did not change during the study period, the increase in prealbumin levels suggests a favourable anabolic effect of total enteral nutrition.

99mTc red blood cell scintigraphy is a non invasive diagnostic method for low flow gastrointestinal bleeding.To assess the diagnostic yield of this method in patients admitted with gastrointestinal bleeding in whom upper gastrointestinal endoscopy was negative.The clinical records of 59 patients, aged 6 to 90 years old (35 male), with active gastrointestinal bleeding subjected to a 99mTc red blood cell scintigraphy were reviewed. All had non diagnostic upper gastrointestinal endoscopic studies, and in 20 a selective arteriography was performed.In 40 patients the scintigraphy was positive for gastrointestinal bleeding, and in 57% of these the exam was positive during the first hour. Fifteen of the 19 patients with a negative scintigraphy did not have an active clinical bleeding at the moment of the examination. In 24 patients, a final etiological diagnosis was reached. In 93% of these patients scintigraphy correctly identified the bleeding site. In one patient with a negative scintigraphy, angiography disclosed a pseudo aneurysm of the splenic artery that was not bleeding actively.In these patients with negative upper gastrointestinal endoscopy 99mTc red blood cell scintigraphy had a 91% sensitivity for the diagnosis of active gastrointestinal bleeding.

Studies have shown that angiotensin converting enzyme (ACE) inhibition prevents left ventricular remodeling and cardiovascular events after an acute myocardial infarction. The role of aldosterone in ventricular remodeling after a myocardial infarction has not been addressed.To compare the effects of an ACE inhibitor, an aldosterone receptor antagonist and placebo on left ventricular remodeling after a first episode of transmural acute myocardial infarction.Patients hospitalized for a first episode of acute myocardial infarction were blindly and randomly assigned to receive ramipril (2.5 mg bid), spironolactone (25 mg tid) or placebo. Ejection fraction, left ventricular end diastolic and end systolic volumes were measured by multigated radionuclide angiography, at baseline and after six months of treatment.Twenty four patients were assigned to placebo, 31 to ramipril and 23 to spironolactone. Age, gender, Killip class, treatment with thrombolytics, revascularization procedures and use of additional medications were similar in the three groups. After six months of treatment, ejection fraction increased from 34.5 +/- 2.3 to 40.2 +/- 2.4% in patients on ramipril, from 32.6 +/- 2.9 to 36.6 +/- 2.7% in patients on spironolactone, and decreased from 37 +/- 3 to 31 +/- 3% in patients on placebo (ANOVA between groups p0.05). Basal end systolic volume was similar in all three groups, increased from 43.4 +/- 3.4 to 61.4 +/- 6.0 ml/m2 in patients on placebo and did not change in patients on spironolactone or ramipril (ANOVA p0.05). End diastolic volume was also similar in the three groups, increased from 70.6 +/- 4.3 to 92.8 +/- 6.4 ml/m2 in patients on placebo and did not change with the other treatments.Ramipril and spironolactone had similar effects on ventricular remodeling after acute myocardial infarction, suggesting that aldosterone contributes to this phenomenon and that inhibition of its receptor may be as effective as ACE inhibition in its prevention.

Screening tests for IG g antibodies against Helicobacter pylori are usefull for a long follow up of patients who were well eradicated. The aim of this study was to determinate and compared sensibility, specificity, positive and negative predictive value of six qualitative serological tests for IG g antibodies detection in the diagnosis of H. Pylori infections. Between May and October 1996 52 patients (30 males and 22 females; median age 42.4 years, range 21-68) with H. Pylori infection assessed on two antral and two corpus biopsies by means of Giema stain and a rapid urease test were tested for IG g antibodies detection. The serological tests used were: Inmunocomb II (Orgenics) Enzimo Inmuno Assay Inmunoadsorbent qualitative, Flex Pack (Smith Kline Diagnostics, Abbott) inmunocromatographic cualitative, Pylori Stat test (Biowhittaker) Enzimo Inmuno Assay (ELISA) qualitative, Premier (Meridian Diagnostics) Enzimo Inmuno Assay ELISA) qualitative. Pyloristest (Orion Diagnóstica) latex aglutination qualitative, H. Pylori (Bio Tre) Enzimo Inmuno Assay cualitative. 10 healthy subjects with negative gastric biopsies and negative rapid ureasa test were used as control group. The six evaluated serological tests have a comparable sensibility (89-95%) and specificity (77-83%) for the diagnosis of HP infection. The presence of specific HP antibodies in infected patients revealed a strong correlation with the histological demonstration of the microrganisms. We can recommend this qualitative serological tests due to their high sensibility and specificity, simplicity and low cost.

153SmEDTMP was obtained from enriched 152Sm irradiated at the 5 MW Chilean Research Reactor and labelled at a molar ratio of 15:1 pH 7.5. Biodistribution, autoradiography, radiochemical purity tests were done for evaluation. 40 patients were treated with 37-55 MBq/kg weight. Bone scans using 99mTcHMDP were obtained prior and after treatment. Bone marrow depression was observed in 37% of them and normal liver function in all of them. In 45% the pain dissapear completely, in 22.5% significantly decreased and partially in 30%. In 17 patients more than one dosis was injected. Our preliminary results indicate that 153SmEDTMP is a promising radiotherapeutic agent for palliative treatment of metastatic bone cancer pain and encourage its use specially because it can be produced in countries with low economic resources, thus a large number of patients can get the benefits of this new procedure.

Because improved understanding of the natural history of thoracic aneurysms would enhance our ability to determine in which cases the risk of surgical treatment is justified, the rate of enlargement of thoracic aneurysms and thoracoabdominal aneurysms was studied in 67 patients by means of serial computer-generated three-dimensional reconstructions of computed tomographic scans. Patients were followed for a mean of 1.5 +/- 0.15 years (0.2 to 5.35 years) with an average interval between examinations of 0.9 +/- 0.1 year (0.2 to 5.0 years). Thirty-nine patients continue to be followed; 7 were lost to follow-up; 14 died during follow-up (4 after aneurysm rupture), and 10 underwent an operation. Indications for operation included the presence of pain, an absolute aortic diameter larger than 8 cm, an increase in aortic diameter of more than 1 cm per year, or marked irregularity of aneurysm contour. Aortic diameter and volume data were generated from the aortic silhouette obtained by tracing each computed tomographic slice with a translucent digitizing tablet. Estimated change in aortic diameter after 1 year was 0.43 cm; estimated change in aortic volume was 88.1 ml. The impact of possible risk factors on the enlargement of aneurysms was examined by analysis of variance (p0.05). A significantly higher rate of aneurysm expansion was found in patients with a larger aortic diameter (5 cm) at diagnosis (change in diameter = 0.17 cm versus 0.79 cm; change in volume = 40 ml versus 141.8 ml), and in smokers (change in diameter = 0.35 cm versus 0.70 cm; change in volume = 78.3 ml versus 120.8 ml). Changes in diameter and volume for aneurysms of different initial diameters and volumes was predicted by exponential regression by the equations: change in diameter = 0.0167 (initial aortic diameter)2.1; change in volume = 0.0356 (initial aortic volume)1.322. No correlation was noted between the rate of enlargement and age, sex, or the presence of dissection. A history of hypertension correlated with a greater aortic diameter at diagnosis but did not significantly affect the rate of enlargement.(ABSTRACT TRUNCATED AT 250 WORDS)

This study was undertaken to determine the factors that influence the final outcome after hypothermic circulatory arrest. Between 1985 and 1992 a uniform method of hypothermic circulatory arrest was used in 200 patients as the primary method of cerebral protection during operations on aneurysms of the thoracic aorta. There were 30 hospital deaths (15%). Age greater than 60 years (relative risk 3.7, p0.02), emergency operation and hemodynamic compromise (relative risk 22.2, p0.000), concomitant procedures (relative risk 2.7, p0.04), presentation with new neurologic symptoms (relative risk 5.2, p0.04), and postoperative permanent neurologic deficits (relative risk 9.4, p0.000) were found to be significant predictors of operative mortality. A total of 183 patients were available for evaluation of neurologic function and outcome. Multivariate analysis of this cohort of patients by multiple logistic regression showed that temporary neurologic dysfunction occurred in 36 cases (19%). Temporary neurologic dysfunction correlated with the duration of hypothermic circulatory arrest (47 +/- 16 minutes; odds ratio 1.06/minute; p0.001) and age (66 +/- 14 years; odds ratio 1.07/year; p0.001). Embolic strokes occurred in 22 patients (11%) and were associated with permanent deficits in 13 (7%). Strokes correlated significantly with age (older than 60, 21% versus younger than 60, 1%; p0.001) and operations on the arch and descending aortic aneurysms containing clot or atheroma (p0.001). This experience shows that the operative mortality is not affected by any parameters related to the use of hypothermic circulatory arrest. The incidence of temporary neurologic dysfunction rises linearly in relation to the age of the patient and the duration of hypothermic circulatory arrest. However, permanent neurologic injury is a result of thromboembolic events and is not related to the method of cerebral protection used. Additional methods to prevent perioperative embolic strokes are needed. Hypothermic circulatory arrest affords adequate cerebral protection if the arrest period is kept less than 60 minutes. We will continue to use this modality until the safety and utility of the alternate methods of cerebral protection are shown to be superior.

Surgery has an important role in the treatment of Crohn's disease (CD). The objective of this communication is to assess the results of surgical treatment in CD, trying to identify recurrence risk factors. A retrospective review of the charts of 120 patients with CD seen between 1963 and 1990 was made. One third of these patients required surgical treatment. The series was divided in two groups. Group A comprised patients treated from 1963 to 1977. Of these, 30% had ileal localization of the disease and 20 patients were submitted to 20 surgical procedures. The major surgical indication was intestinal obstruction and resection was performed in 85% of patients. Morbidity was 20% and mortality 10%. Group B comprised patients treated from 1978 to 1990. Nineteen patients were submitted to 22 surgical procedures. The disease was localized in the ileon in 50% of these patients. Twenty one surgical procedures were resective with a 9% complication rate and no surgical mortality. Eighty percent of patients in this group has a complete follow up. In 47% the disease recurred 37 months (as a mean) after surgery. No effect of age, sex or localization of the disease on the risk of recurrence was observed. It is concluded that morbidity and mortality of surgical treatment for Crohn's disease has decreased and a prolonged control of symptoms has been achieved. No recurrence risk factors were identified in this study.

We evaluated a pre-tinning leukocyte labeling technique using Glucoheptonate-Sn lyophilized kit, in the detection of activity in 15 patients with clinical and laboratory signs of active inflammatory bowel disease (IBD). 25 patients, without gastrointestinal disease were the control group. In 7/8 patients with Crohn's disease and in 7/7 with Ulcerative Colitis the study was positive. The negative study corresponded to a patient who has only involvement of the duodenum, an area of difficult evaluation due to the high liver uptake. 3/25 patients of the control group had activity in the intestine at 4 hour images. In spite of the small group evaluated, we believe that this labeling technique is a promising procedure for evaluation of activity in patients with IBD (Sensitivity 93.3%, Specificity 88.0%).

Out of 103 consecutive patients with ulcerative cholitis, 37 required surgery. We compared perioperative morbidity and mortality in 18 patients receiving intensive nutritional care with 9 controls. An increase in serum albumin form 2.8 +/- 0.5 to 3.4 +/- 0.4 mg/dl (p less than 0.01) and lymphocytes from 1210 +/- 614 to 1736 +/- 770 (p less than 0.05) was observed in the first group, but not in the second. No deaths, shorter hospital stay and fewer complications were observed in the first group. We conclude that intensive nutritional care should be routinely used in patients with severe ulcerative cholitis requiring surgery.

The effects of increased biliary resistance on bile secretion and biliary permeability properties were studied in rats. High biliary resistance produced significant reductions in bile flow and the secretion rate of cholesterol, but did not modify bile salt and phospholipid secretory rates. Decreased bile flow appeared to be secondary to a marked reduction in bile salt-independent fractions of bile flow, and bile salt-dependent flow was simultaneously increased. 14C-erythritol and 3H-inulin clearance studies suggest that decreased net canalicular secretion of water rather than increased water reabsorption at the biliary ducts is the mechanism involved in decreased bile flow. In addition, a marked increase in canalicular permeability to inulin was evident when rats were secreting against increased biliary resistance as well as during recovery.

It has been previously shown that rats subjected to obstructive cholestasis demonstrate in the postcholestatic period, after release of common duct obstruction, a marked increase in canalicular bile flow relative to bile acid excretion. To characterize this phenomenon further, we investigated whether changes in canalicular permeability and in the activity of (Na+-K+)-ATPase in isolated liver surface membranes are associated with postcholestatic choleresis. With this purpose, the clearances of 14C-erythritol and 3H-insulin were simultaneously measured in rats subjected to a 3-day obstructive cholestasis and in controls, during spontaneous choleresis as well as during the intravenous infusion of sodium taurocholate at both submaximal and saturating rates. In additional groups of bile duct-ligated rats and controls, liver surface membrane fractions were isolated, and the activity of appropriate marker enzymes and (Na+-K+)-ATPase was determined. In both groups 14C-erythritol clearance closely approximated total bile flow, suggesting that bile flow was of canalicular origin. However, cholestatic rats showed a sixfold increase in 3H-inulin clearance compared to controls. These results suggest that canalicular permeability to inulin is markedly increased in cholestatic rats. On the other hand, (Na+-K+)-ATPase activity was significantly higher in cholestatic rats than in controls in both homogenate (1.27 +/- 0.07 and 0.89 +/- 0.07 U/mg of protein, respectively, p less than 0.001) and liver surface membranes (22.6 +/- 1.2 and 17.5 +/- 1.2 U/mg of protein, respectively, p less than 0.001). Thus enhanced choleretic response to bile acids in the postcholestatic period is associated with an increased permeability of canalicular structure to inulin and with a significant increase in both homogenate and surface membrane (Na+-K+)-ATPase activity. In addition, this study points out some important differences between bile secretory function of rats subjected to obstructive cholestasis and that described in models of bile secretory failure induced by drugs or monohydroxy-bile acids.

Bile secretory function was studied in rats subjected to a 7-day obstructive cholestasis induced by complete common duct obstruction. Bile flow and bile acid excretion were examined during bile depletion, following the release of the biliary obstruction, and during the infusion of sodium taurocholate at submaximal and saturating rates. A highly significant increase, greater than 100%, in bile flow was evident in cholestatic rats at any bile acid excretory rate, when compared to control sham-operated rats. 14C-erythritol clearance measurements performed during bile depletion and during the infusion of taurocholate suggest that bile flow was mainly of canalicular origin in cholestatic rats. Estimated taurocholate transport maximum (mumol/min per rat) was not statistically different between cholestatic and control rats. However, significantly greater taurocholate plasma levels at Tm in cholestatic rats suggest a decreased efficiency of the bile acid transport process. In addition, the relationship between bile flow and bile acid excretion was found to be nonlinear at low bile acid excretory rates in cholestatic rats. Thus important changes in bile formation occurred in rats subjected to temporary obstructive cholestatis, which differ from those observed in other models of cholestasis that are associated to a reduction in bile flow and bile acid transport capacity.