Higher postoperative pain and increased morphine consumption follow pre- rather than post-incisional single dose epidural morphine.

BACKGROUND: Neuraxial administration of morphine is an effective way of controlling postoperative pain and reducing analgesic consumption. Some animal models have demonstrated that preemptive administration of neuraxial narcotics reduces pain, while others have revealed the contrary. In addition, there have been no consistent results in clinical settings. This double-blind, randomized study compared the effects of pre- vs. post-incisional administration of neuraxial morphine on postoperative pain perception and analgesic requirements over 48 hours following laparotomy for open colectomy under standardized general anesthesia. METHODS: Twenty patients received epidural morphine (3 mg) before the incision and saline after wound closure (MO1 group), and twenty patients received epidural saline before the incision and morphine after wound closure (MO2 group). Postoperatively, all patients received morphine boluses (1.5 mg) via intravenous patient-controlled analgesia (IV-PCA) and rescue doses of intramuscular diclofenac (75 mg) every 6 hours, as needed. RESULTS: MO1 patients used significantly (P<0.05) more morphine than the MO2 group during the first 24 postoperative hours and activated the PCA device more frequently throughout the 48-hour study period. The MO1 group was characterized by significantly (P<0.05) higher self-rated pain scores than the MO2 group throughout the study. The self-rated levels of sedation and satisfaction of the MO2 patients were also consistently better (P<0.05) than those of the MO1 patients, especially during the second postoperative day. CONCLUSION: Pre-incisional epidural morphine in patients undergoing open colonic surgery under general anesthesia was associated with more postoperative pain, a greater need for analgesics, and poorer patient satisfaction compared to post-incisional morphine administration.

The midazolam-induced paradox phenomenon is reversible by flumazenil. Epidemiology, patient characteristics and review of the literature.

BACKGROUND AND OBJECTIVE: Midazolam may occasionally precipitate hostility and violence instead of tranquility. We characterized these episodes, their rate of occurrence, the potential paradoxical responders and possible predisposing circumstances among patients undergoing lower body surgery under spinal or epidural anaesthesia and midazolam sedation. PATIENTS AND METHODS: Fifty-eight patients who fulfilled the study entry criteria and who underwent surgery within a 3-month period in a large metropolitan, university-affiliated hospital were enrolled. Sedation and restlessness in all patients were controlled by midazolam administered intravenously by the attending anaesthesiologist; these parameters were later objectively confirmed by recorded actigrams. If "paradoxical" events occurred, flumazenil 0.1 mg 10 s-1 was injected until the aberrant behaviour ceased. Patients with paradoxical reactions were later compared with matched control patients selected from the study group to identify epidemiological characteristics. RESULTS: The incidence of paradoxical events was 10.2% (six out of 58 patients, confidence limits 2.3-18.3%) and they occurred 45-210 min after sedation started; the only independent predictor was an age older than that of the entire study group. The mean cumulative and per weight doses of midazolam were similar for both the experimental and the study groups of patients: 7.3 +/- 2.8 to 10.1 +/- 3.6 mg, and 0.1 +/- 0.04 to 0.12 +/- 0.05 mg kg-1. Flumazenil 0.2-0.3 mg (range 0.1-0.5 mg) effectively stopped the midazolam-induced paradoxical activity within 30 s and surgery continued uneventfully. CONCLUSIONS: Flumazenil completely reverses midazolam-induced paradoxical reactions and they are more frequent in older patients.

Novel adapter protein AP162 connects a sialyl-Le(x)-positive mucin with an apoptotic signal transduction pathway.

Glycoproteins modified with a sialyl-Le(x)-moiety are important sensors for extracellular signals regulating cellular recognition, adhesion and migration. The transduction pathways and signals mediated by these glycoproteins within the cell are largely unknown. In search of novel glycoproteins modified with sialyl-Le(x)-moiety, we screened a human colonic cDNA expression library with a rabbit antiserum produced against sialyl-Le(x)-positive mucins. The antiserum detected a new protein, named B2, which was cloned and characterised in detail. The analysis of the B2 gene revealed a 5.7 kb RNA transcript detectable in all investigated tissues and a complete coding sequence of 2778 bp. The B2 protein exhibited two putative PH (pleckstrin homology) domains and a leucine zipper motif but no homology to any known proteins. Monospecific antibodies against the B2-protein precipitated from the solubilised membrane fraction of the colon carcinoma cell line LS 174T a protein with an apparent Mr = 162 kDa and, additionally, a mucin-like glycoprotein with an apparent Mr = 220 kDa. Protein fractionation on a CsCl gradient, Western blots and sandwich ELISA showed that the 220 kDa mucin carries the sialyl-Le(x) moiety and is tightly bound to the 162 kDa protein. The expression of the recombinant B2-protein enhanced staurosporine-induced apoptosis in epithelial cancer cell lines. These data indicate that B2 is a novel, ubiquitously expressed protein with a putative adapter function. The protein has been named AP162 (adapter protein 162). In colon carcinoma cells B2-protein is tightly associated with a sialyl-Le(x)-positive mucin and has a potential for involvement in sialyl-Le(x)-mediated transduction of apoptotic signals.

[FK506 (tacrolimus) does not increase hepatic damage due to hypoperfusion].

Deterioration of hepatic function following liver transplantation is a known complication, sometimes attributed to the use of cyclosporin A. Reaction to tacrolimus (Prograf), a relatively new and effective immunosuppressant drug, is thought to result in a much lower grade of organ dysfunction, especially in the transplanted liver. Using the ex-vivo rat model of isolated perfused liver, we evaluated hepatocellular damage and oxygen extraction when tacrolimus was administered following liver hypoperfusion. Tacrolimus did not worsen hepatic dysfunction caused by the hypoperfusion. Therefore using tacrolimus in the perioperative period might be safer than cyclosporin A, which tends to worsen hepatic damage in the presence of hypoperfusion.

Dexmedetomidine: a promising agent for anesthesia and perioperative care.

Dexmedetomidine is a relatively new, highly selective, short-acting central alpha 2 agonist. Although not yet officially introduced for clinical use in Israel, it has become increasingly popular among anesthesiologists and intensive care physicians abroad when used as an adjuvant to the classical regimen of anesthesia techniques. Its administration potentiates the effect of other sedative and hypnotic agents while causing minimal respiratory depression. It also blunts the sympathetic response--thus minimizing changes in blood pressure and heart rate--during critical moments such as laryngoscopy and intubation. However, bradycardia and hypotension may ensue. DXM minimizes opioid-induced muscle rigidity and attenuates postoperative shivering. These pro-anesthesia effects are attributed to the capability of DXM to reduce central adrenergic outflow. Although its precise mechanism(s) of action are still debatable, DXM will undoubtedly find an increasing role in clinical peri-operative anesthesia.

Fucosyltransferase III and sialyl-Le(x) expression correlate in cultured colon carcinoma cells but not in colon carcinoma tissue.

The potential contribution of fucosyltransferases to the overexpression of sialyl-Le(x) antigen was investigated in the colon carcinoma cell line HT-29 and in human colon carcinoma tissue. In HT-29 cells as well as in normal or malignant colonic tissues Fuc-TIII, Fuc-TIV, Fuc-TVI but not Fuc-TV nor Fuc-TVII were detectable after RT-PCR. Sodium butyrate treatment of HT-29 cells increased (to about 200%) and DMSO treatment decreased (to about 20%) the expression of sialyl-Le(x). This modulation of sialyl-Le(x) was concomitant with the analogous increase/decrease of mRNA of Fuc-TIII but not Fuc-TIV. Fuc-TVI was not detectable by Northern blotting in HT-29 cells. In six human colon carcinomas which exhibited strong overexpression of sialyl-Le(x), the expression of Fuc-TIII-mRNA was the same or lower than in the corresponding normal colonic tissue. Thus Fuc-TIII expression may be affecting the expression of the sialyl-Le(x) moiety in HT-29 cells but not in human colon carcinoma tissue.

Low frequency of p53 gene mutation and protein expression in mucinous colorectal carcinomas.

Immunohistochemical data indicate that the frequency of p53 protein overexpression is consistently lower in the mucinous than in the non-mucinous carcinomas of the breast, ovary, pancreas and colon. This peculiar immunohistochemical behavior of the mucinous phenotype could be due to the effect of large amounts of mucus on the staining or to an actual mutation frequency difference between mucinous and non-mucinous carcinomas. This question was investigated on a group of mucinous colorectal carcinomas. DNA was extracted from paraffin sections of 16 human mucinous colorectal carcinomas and the mutation frequency was determined by sequencing of p53 exons amplified in PCR. The expression of p53 protein was determined with the avidin-biotin complex-peroxidase staining procedure and CM-1 antiserum. Twenty-five percent of the tumors, exhibited p53 protein overexpression and in 31% a mutation was detected. Concordance between the two techniques was found in 69% of tumors. Overexpression without mutation was observed in 12% and mutation without overexpression in 19%. G:C --> A:T transitions represented the most frequent lesion (80%), as previously observed in non-mucinous colorectal carcinomas. These data indicate that the mutation pattern in the p53 gene is similar in mucinous and non-mucinous colorectal carcinomas. The low frequency of p53 overexpression in the mucinous phenotype is not due to a mucus effect on the staining but is related to the low mutation frequency of p53 gene. These results lead to the hypothesis that in contrast to the nonmucinous tumors the development of the majority of colonic carcinomas with the mucinous phenotype may be independent from p53 mutations.

Characterization of the major sialyl-Lex-positive mucins present in colon, colon carcinoma, and sera of patients with colorectal cancer.

The expression of the mucin-bound sialyl-Lewisx epitope is increased in the tissue of most colorectal carcinomas and in the sera of about 30% of tumor patients. In colon cancer, a portion of the sialyl-Lex groups detectable with the monoclonal antibody AM-3 is located on MUC1 (C. Hanski et al., Cancer Res., 53: 4082-4088, 1993). In order to characterize the major colon carcinoma-associated sialyl-Lex-positive glycoprotein components, the tissue- and serum-derived antigens were investigated. The buoyant densities of the sialyl-Lewisx-positive antigens from tumor and normal colonic tissues and from sera of patients with colon carcinoma and healthy donors correspond to that of mucins (1.40 g/ml). The sialyl-Lex-positive mucins purified from both tissues elute under nonreducing conditions in the void volume of a Sepharose CL-2B column, indicating a molecular mass more than 2 x 10(7) daltons. They yield in immunoblot after SDS gel electrophoresis under reducing conditions a main band at an apparent M(r) 880,000. Radioactive labeling revealed that the band at M(r) 880,000 is the major protein component in sialyl-Lewisx-positive mucins both from tumor and normal colonic tissue. In sera of colon carcinoma patients, the sialyl-Lex moiety is also detectable mainly on a M(r) 880,000 glycoprotein band and, additionally, on a M(r) 140,000 molecule as well as on alpha 1-acid glycoprotein. Sera from healthy donors exhibited only a sialyl-Lex-positive glycoprotein with the apparent M(r) 140,000. Sandwich ELISA as well as immunoblots of mucins purified from the colon carcinoma cell line LS174T indicated that the sialyl-Lex moiety migrating in the M(r) 880,000 band is located on MUC2 protein core. Together, these data suggest that sialyl-Lex antigen in colon, colon carcinoma, and the sera of patients with this tumor is located on the MUC2 molecule, consisting of several subunits with an apparent M(r) 880,000, linked via disulfide bridges. The increase of sialyl-Lex expression in colon carcinomas appears to be mainly due to a more frequent transfer of sialyl-Lex moieties onto the mucin core in tumor tissue.

The overexpression of the sialyl-lewis(x) moiety is an independent and a more consistent marker of colon carcinogenesis than the overexpression of C-myc and ki-ras oncogenes.

The expression of the carbohydrate antigen sialyl-Le(x) and of the oncogenes c-myc and Ki-ras increases after malignant transformation of the colorectum. Since the overexpression of these two oncogenes may affect O- or N-linked carbohydrate chain synthesis, we investigated if this is the case for sialyl-Le(x). In parallel sections from 11 adenomas and 9 colorectal carcinomas Ki-ras and c-myc mRNAs were detected by in situ hybridization and sialyl-Le(x) by immunohistochemistry. The moderate to high overexpression of sialyl-Le(x) found in 64% of adenomas and in 89% of carcinomas is a sharply delineated process, closely related to the local stage of tissue transformation. By contrast, the moderate to high overexpression of c-myc mRNA detected in 27% of adenomas and in 78% of carcinomas affects the whole adenomatous or carcinomatous tissue in a homogeneous manner. The Ki-ras mRNA was moderately and homogeneously overexpressed in 18% of adenomas and in 11% of carcinomas, but its expression level did not differ in adenoma and carcinoma of the same specimen. The independence of the three alterations was confirmed in HT-29 cells and its subclones 16.2 and 15.2, in which the relative amounts of total sialyl-Le(x) epitope were 100%: 67%: 38% while the amounts of c-myc mRNA or Ki-ras mRNA determined by Northern blotting did not vary. These data indicate that in human colon the expression of sialyl-Le(x) is independent from c-myc or Ki-ras oncogenes. It occurs more frequently in the early stage of transformation and is more consistently associated with the malignant process than the overexpression of either oncogene.

Altered glycosylation of the MUC-1 protein core contributes to the colon carcinoma-associated increase of mucin-bound sialyl-Lewis(x) expression.

The mucin carbohydrate epitope sialyl-Le(x), detected with the monoclonal antibody AM-3, is strongly overexpressed in > 90% of human colon carcinomas. We show here that in colon carcinoma one of the mucin cores bearing the sialyl-Le(x) group is MUC-1, whereas sialyl-Le(x) present in normal colon is not detectable on MUC-1. The amounts of MUC-1 core detectable with the monoclonal antibody BC3 in extracts of tumor tissue are 60-180% of those in normal tissue. Two other carbohydrate epitopes located on MUC-1 in mucins from normal and tumor tissue have also been characterized. In contrast to sialyl-Le(x), their expression on MUC-1 is variable and does not correlate with the malignant transformation of colonic mucosa. The transfer of the sialyl-Le(x) group onto the MUC-1 core contributes to the colon carcinoma-associated overexpression of the sialyl-Le(x) epitope.

The effects of halothane, enflurane and isoflurane on the isolated rat heart recovering from cardioplegic arrest.

The direct cardiac effects of volatile anesthetics following cardioplegic ischemia were investigated in isolated, paced rat hearts. In one series of experiments, the hearts were perfused with oxygenated Krebs Henseleit solution for a 15-minute stabilization period and then the effect of the volatile anesthetic was tested. In another series of experiments, after the stabilization period, the hearts were subjected to cardioplegic (KCl 20mEq/L) ischemia at 30 degrees C for 30 minutes and then the effect of the volatile anesthetic was tested. Halothane, enflurane or isoflurane was introduced to the Krebs Henseleit solution at 0.7 and 1.4 minimal alveolar concentration. All the volatile anesthetics decreased myocardial contractility in a dose dependent manner both before and after cardioplegic arrest. Halothane decreased coronary flow, while isoflurane and enflurane increased coronary flow in both the cardioplegic and non-cardioplegic hearts. The influence of the anesthetics was transient and ceased once they were withdrawn. Ischemic cardioplegia did not affect the response to volatile anesthetics.