CpG island methylation is a common finding in colorectal cancer cell lines.

Tumour cell lines are commonly used in colorectal cancer (CRC) research, including studies designed to assess methylation defects. Although many of the known genetic aberrations in CRC cell lines have been comprehensively described, no studies have been performed on their methylation status. In this study, 30 commonly used CRC cell lines as well as seven primary tumours from individuals with hereditary nonpolyposis colorectal cancer (HNPCC) were assessed for methylation at six CpG islands known to be hypermethylated in colorectal cancer: hMLH1, p16, methylated in tumour (MINT-)-1, -2, -12 and -31. The cell lines were also assessed for microsatellite instability (MSI), ploidy status, hMLH1 expression, and mutations in APC and Ki-ras. Methylation was frequently observed at all examined loci in most cell lines, and no differences were observed between germline-derived and sporadic cell lines. Methylation was found at MINT 1 in 63%, MINT 2 in 57%, MINT 12 in 71%, MINT 31 in 53%, p16 in 71%, and hMLH1 in 30% of cell lines. Overall only one cell line, SW1417, did not show methylation at any locus. Methylation was found with equal frequency in MSI and chromosomally unstable lines. MSI was over-represented in the cell lines relative to sporadic CRC, being detected in 47% of cell lines. The rate of codon 13 Ki-ras mutations was also over three times that expected from in vivo studies. We conclude that CpG island hypermethylation, whether acquired in vivo or in culture, is a ubiquitous phenomenon in CRC cell lines. We suggest that CRC cell lines may be only representative of a small subset of real tumours, and this should be taken into account in the use of CRC cell lines for epigenetic studies.

Ondansetron in the prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy: a prospective randomized study.

BACKGROUND: There is an increased incidence of postoperative nausea and vomiting (PONV) after laparoscopic cholecystectomy. The aim of the study was to evaluate the efficacy of intravenous ondansetron, a 5-HT anatagonist, for prevention from PONV after laparoscopic cholecystectomy. METHODS: Sixty-eight patients were entered into the study. Thirty-six patients were randomized to receive a single intravenous dose of 4 mg of ondansetron before extubation. Thirty-two patients received no prophylaxis. There were no differences in terms of sex ratio, age, ASA status, and duration of operation between the two study groups. Patients were interviewed by an independent observer to assess the postoperative pain and nausea using visual analog score. Patients' satisfaction scores to the procedure were measured. RESULTS: There was no complication in the series. Pain scores at 2 and 24 h after operation and analgesics consumption were not different between the two groups. For the patients who received ondansetron, the mean (SD) nausea score at 2 and 24 h was 1.5 (1.2) and 1.4 (1.4), respectively. The score for the control group was 1.4 (1.0) and 1.2 (0.5), respectively. There was also no difference in episodes of vomiting and usage of antiemetics between the two groups. Both groups were equally satisfied with the procedures. CONCLUSION: Routine use of ondansetron does not reduce the incidence of postoperative nausea and vomiting after laparoscopic cholecystectomy.

Intraoperative single-shot "3-in-1" femoral nerve block with ropivacaine 0.25%, ropivacaine 0.5% or bupivacaine 0.25% provides comparable 48-hr analgesia after unilateral total knee replacement.

PURPOSE: To compare analgesia after intraoperative single shot "3-in-1" femoral nerve block (FNB) in combination with general anesthesia using ropivacaine 0.25%, ropivacaine 0.5% with bupivacaine 0.25% for total knee replacement (TKR). METHODS: We performed a randomized, double-blind study in 48 patients for elective TKR under general anesthesia. Patients were randomized to one of four groups (C: sham block, R1: "3-in-1" FNB using 30 mL of ropivacaine 0.25%, R2: "3-in-1" FNB using 30 mL of ropivacaine 0.5%, B: "3-in-1" FNB using 30 mL of bupivacaine 0.25%). Verbal pain score (VPS) both at rest and movement were assessed for 48 hr after TKR (0=none; 1=mild; 2=moderate; 3=severe). Total morphine consumption and its associated side effects, duration of hospitalization after operation were also compared. RESULTS: There were no differences in patients' physical characteristics, intraoperative morphine usage, operation time, tourniquet time or length of hospitalization between the four groups. When compared with group C, the VPS was significantly lower in groups R1, R2 and B at one, four, eight, 24 and 48 hr after TKR (P <0.05). The morphine requirement of groups R1, R2 and B were also significantly lower when comparing with group C up to 48 hr postoperatively (P <0.05). There were no significant differences in VPS and postoperative morphine requirement at any time between groups R1, R2 and B. CONCLUSION: "3-in-1" FNB with ropivacaine provided analgesia that was clinically comparable to that of bupivacaine up to 48 hr after TKR. Increasing the concentration of ropivacaine from 0.25% to 0.5% failed to improve the postoperative analgesia of "3-in-1" FNB.

Role of tramadol in reducing pain on propofol injection.

Propofol is frequently associated with pain on injection. We evaluated the effect of tramadol in a randomised, double-blind study using a tourniquet venous retention technique. Normal saline placebo was given intravenously to patients in Group 1 (n = 30),tramadol 50 mg to Group 2 (n = 30), and lignocaine 50 mg to Group 3 (n = 30). The venous retention of drugs was maintained for 1 minute, followed by tourniquet release and intravenous administration of propofol. Pain assessment was made immediately after propofol injection. There was a significant reduction in the incidence of pain associated with propofol administration in patients pretreated with lignocaine and tramadol (P < 0.05). In addition, pretreatment with tramadol was as effective as lignocaine in reducing pain on propofol injection.

Sevoflurane induction in the elderly.

The effects of 2% and 4% sevoflurane in oxygen and nitrous oxide for induction of anaesthesia in 60 unpremedicated elderly patients was compared to those obtained during an intravenous Thiopentone induction. Intravenous induction induced anaesthesia in 27 +/- 5 seconds, significantly faster than a 2% or 4% sevoflurane induction (109 +/- 36 and 71 +/- 24 seconds respectively). One patient in both the thiopentone and 2% sevoflurane groups, and 2 patients in the 4% sevoflurane group coughed during induction. The postinduction reduction in mean arterial pressure was greatest in the thiopentone group followed by the 4% and the 2% sevoflurane groups. Heart rate changes were minimal in all groups. We conclude that 2% or 4% sevoflurane offered suitable conditions for induction of anaesthesia in the elderly with minimal cardiovascular derangement.

Sevoflurane-fentanyl versus etomidate-fentanyl for anesthetic induction in coronary artery bypass graft surgery patients.

OBJECTIVE: To compare the hemodynamic effects of sevoflurane-fentanyl with etomidate-fentanyl during anesthetic induction in patients with coronary artery disease with good left ventricular function. DESIGN: A prospective randomized trial. SETTING: University hospital. PARTICIPANTS: Twenty patients scheduled for elective coronary artery bypass graft surgery. INTERVENTIONS: Patients were allocated randomly to receive either 4% sevoflurane/nitrous oxide 67%/oxygen 33% (sevoflurane group) or etomidate, 0.2 mg/kg, for induction (intravenous group). Both techniques were supplemented by 10 microg/kg of fentanyl and muscle relaxation with pancuronium. Anesthesia was maintained in both groups with 2% sevoflurane/nitrous oxide 67%/oxygen 33%. MEASUREMENTS AND MAIN RESULTS: Time to loss of consciousness and airway complications during induction were assessed. Hemodynamics were recorded at 1-minute intervals during the induction period up to 5 minutes postintubation. Induction of anesthesia was significantly faster in patients given etomidate compared with patients who received sevoflurane; loss of eyelid reflex was 45 seconds (standard deviation 17 seconds) versus 97 seconds (standard deviation 20 seconds). None of the patients who received sevoflurane had airway complications during the induction period. Both anesthetic induction techniques provided cardiostability with little change in cardiac index (2%). The decrease in mean arterial blood pressure was greater in the patients who received sevoflurane induction (maximal decrease 28% v 14%). The heart rate and filling pressure changes were insignificant. CONCLUSION: Sevoflurane inhalation induction produced minimal changes in cardiac index and no airway complications in patients with coronary artery disease with good left ventricular function. Induction was faster with etomidate, however, and blood pressure remained higher.

Pain on injection of rocuronium: influence of two doses of lidocaine pretreatment.

We have assessed the incidence of pain on injection of rocuronium and evaluated if pretreatment with lidocaine i.v. reduced it, in a randomized, controlled study in 90 patients. We found that 37% of patients who received lidocaine 10 mg pretreatment had pain on injection of rocuronium compared with 77% of patients who received saline pretreatment and 7% of patients who were pretreated with lidocaine 30 mg (P < 0.05 in each instance compared with control). In addition, patients pretreated with lidocaine were less likely to suffer moderate or severe pain. Both lidocaine 10 mg and 30 mg i.v. given before administration of rocuronium significantly reduced the incidence and severity of pain on injection of rocuronium, and the higher dose was more effective.

Placement of left-sided double-lumen endobronchial tubes: comparison of clinical and fibreoptic-guided placement.

We have compared a new intubation manoeuvre using a fibreoptic bronchoscope with conventional blind placement of a double-lumen tube. Thirty adult patients who presented for thoracoscopy requiring one-lung ventilation underwent endobronchial intubation with a double-lumen tube inserted either in the conventional blind way or using a fibreoptic bronchoscope. There were four misplacements of the double-lumen tube using the conventional method but none using the bronchoscope. In addition, the bronchoscope allowed more rapid intubation (mean 106 vs 347 s). The results suggest that the fibreoptic-guided method of inserting the double-lumen tube was a satisfactory alternative to the conventional one.

Re-expansion pulmonary oedema following one-lung ventilation--a case report.

Acute ipsilateral or bilateral pulmonary oedema following lung re-expansion after pleurocentesis or treatment of pneumothorax is an unusual clinical phenomenon that may have serious consequences. It usually occurs when the chronically collapsed lung is rapidly re-expanded. There are, however, no reported cases of this complication following one-lung ventilation used to facilitate surgery. A report of the occurrence of unilateral re-expansion oedema in a young female undergoing scoliosis correction is described.

Laryngeal mask insertion using thiopental and low dose atracurium: a comparison with propofol.

PURPOSE: To compare the laryngeal mask airway (LMA) insertion conditions produced by propofol and a thiopental - low dose atracurium combination. METHODS: In a randomized controlled double blind study, 120 premedicated patients were allocated into four groups. After pre-oxygenation, anesthesia was induced as follows: 1 microg x kg(-1) fentanyl, 2.5 mg x kg(-1) propofol (group I); 1 microg x kg(-1) fentanyl, 5 mg x kg(-1) thiopental (group II); 1 microg x kg(-1) fentanyl, 5 mg x kg(-1) thiopental, 0.05 mg x kg(-1) or 0.1 mg x kg(-1) atracurium (groups III and IV respectively). The LMA was inserted by a blinded anesthesiologist who also assessed the following insertion conditions on a three point scale; jaw relaxation, biting, gagging, coughing, presence of laryngospasm, adequacy of airway patency, number of attempts at insertion and overall insertion conditions. RESULTS: There was no difference in insertion conditions between groups I, III and IV. Group II produced the worst overall conditions (P<0.05). There were no differences in hemodynamic changes and apnea times between all four groups. CONCLUSION: The combination of fentanyl-thiopental with low dose atracurium (0.05 or 0.1 mg x kg(-1)) provided conditions comparable with those of propofol for LMA insertion.

Alfentanil co-induction for laryngeal mask insertion.

We assessed the effect of two different doses of alfentanil (5 and 10 micrograms.kg-1) on the conditions for laryngeal mask airway insertion in ASA 1 and 2 patients who received propofol for induction of anaesthesia. One hundred and fifty unpremedicated patients were randomly allocated to receive either propofol 2.5 mg.kg-1 only (Group P), alfentanil 5 micrograms.kg-1 and propofol 2.5 mg.kg-1 (Group A5), or alfentanil 10 micrograms.kg-1 and propofol 2.5 mg.kg-1 (Group A10). The addition of alfentanil to propofol resulted in a greater ease of insertion and a better quality of airway patency. Pretreatment with alfentanil also resulted in a significantly higher success rate during the first attempt at inserting the laryngeal mask airway compared with Group P (Group P 58%, Group A5 96%, Group A10 94%). Patients in Group P were apnoeic for a mean (+/- SD) time of 3.3(+/- 1.9) min, 4.71 (+/- 2.2) min in Group A5, and 7.32(+/- 4.3) min in Group A10. The use of alfentanil 10 micrograms.kg-1 with propofol, however, led to a significant decrease in mean arterial pressure and heart rate. We concluded that pretreatment with intravenous alfentanil 5 micrograms.kg-1 prior to propofol provides excellent conditions for insertion of laryngeal mask with minimal adverse haemodynamic changes.

Anaesthesia for caesarean section in a patient with an intracranial arteriovenous malformation.

Intracranial haemorrhage from an arteriovenous malformation (AVM) during pregnancy is rare but may result in significant maternal and fetal morbidity and mortality. In the untreated patient with an AVM, the best mode of delivery remains debatable with most obstetricians preferring a caesarean section in order to avoid Valsalva manoeuvres associated with vaginal delivery. We describe the administration of epidural anaesthesia for such a parturient undergoing Caesarean section and the anaesthetic implications.

Acute hyponatraemia secondary to cerebral salt wasting syndrome in a patient with tuberculous meningitis.

A 30-year-old HIV-positive man presented with acute hydrocephalus secondary to tuberculous meningitis, for which an external ventricular drain was inserted. He developed marked natriuresis in the postoperative period, which resulted in acute hyponatraemia (131 to 122 mmol/l) and a contraction of his intravascular volume. A diagnosis of cerebral salt wasting syndrome was made, and he responded to sodium and fluid loading. This case highlights the differentiation of cerebral salt wasting syndrome from the more commonly occurring syndrome of inappropriate anti-diuretic hormone secretion as the aetiology of the hyponatraemia.

Esmolol resistance during anesthesia for thoracoscopically assisted coronary artery bypass grafting.

The anesthetic technique for two patients who underwent thoracoscopic harvesting of the LIMA followed by a mini-thoracotomy for surgical myocardial revascularization of isolated LAD artery stenosis is reported. Both patients unexpectedly showed esmolol resistance during anastomosis of the LIMA to the LAD artery. However, excellent graft patency, early extubation, and rapid recoveries were achieved.

UBE3A "mutations" in two unrelated and phenotypically different Angelman syndrome patients.

Angelman syndrome (AS) is a rare neurodevelopmental disorder. Recently, several mutations have been found in the E6-AP ubiquitin protein ligase gene (UBE3A) in a group of patients who are nondeleted and do not have uniparental disomy or imprinting defects. Most of the reported mutations cluster within exons 9 or 16 of the UBE3A gene, and nearly all are predicted to give rise to truncated E6-AP ligases. Here, we describe two AS patients with dissimilar phenotypes. At the molecular level, they are both nondeleted, do not display uniparental disomy, and have normal imprint patterns. One has the typical AS phenotype and carries the previously reported 1344delAG de novo mutation involving a functionally significant region of UBE3A. The other expresses an atypical phenotype in that she has less severe ataxia, no inappropriate laughing, or epilepsy, and her EEG was normal at an early age. A 14-bp deletion in the 3' untranslated region of exon 16 (3'UTRdel14) adjacent to the poly(A) signal was identified. Further investigation revealed that the DNA change was a neutral polymorphism. Haplotype analysis indicated that both the AS patient and her normal sibling had inherited the same maternal UBE3A gene and its 5' flanking region. Although the 14-bp change has no functional significance, it assists with counseling to determine future risks of recurrence in this family.

Endogenous source of bacteria in tracheal tube and proximal ventilator breathing system in intensive care patients.

Although bacteria from both the ventilator breathing system and the gastrointestinal tract have been implicated in the pathogenesis of ventilator-associated pneumonia, an endogenous source of bacteria in the proximal respiratory breathing system has yet to be demonstrated conclusively. We investigated a potential route of bacterial colonization from the stomach contents to the efferent limb of the ventilator breathing system by bacterial culture of daily specimens from six sites in 20 surgical intensive care patients. Gram-negative bacilli were isolated in a progressively increasing proportion of samples at successive sampling points, consistent with an endogenous-to-external route of spread (patients, chi-square = 14.12, P < 0.02; samples, chi-square = 106.15, P < 0.001). Identical strains of gram-negative bacilli, confirmed by REPS typing, were found at two or more sites in seven patients. In all seven, gram-negative bacilli were first isolated from a site in the patient. In none of the 20 patients was there evidence of a sequence of colonization from the ventilator tubing or Y-piece connector towards the patient. Probable colonization sequences plotted from the time of first isolation supported the proposed sequence in six patients, and in five began with the stomach contents. Isolation sequences contrary to the proposed direction of colonization involved four bacterial species and two patients, and did not extend beyond two sample sites. These findings imply that the retrograde route of bacterial colonization of the ventilated lung extends into the proximal respiratory breathing system and may help to identify additional targets for preventive intervention.

Postanaesthetic shivering--a comparison of thiopentone and propofol.

One hundred and sixty patients undergoing minor surgical procedures were randomly allocated to receive either thiopentone or propofol for induction of anaesthesia. All patients were assessed in the recovery period for the development of postanaesthetic shivering. Twenty patients (25%) in the thiopentone group and 8 patients (10%) in the propofol group developed postanaesthetic shivering (p < 0.05). There was no statistically significant difference in tympanic temperature between shivering and nonshivering patients. Propofol as an induction agent is associated with a lower incidence of postanaesthetic shivering as compared to thiopentone.

Variants of chromosome 9 in phenotypically normal individuals.

The human chromosome 9 displays the highest degree of structural variability. Four different types of variants are described including pericentric inversion, extra G-positive band in the q arm, additional G-positive band in the p arm and duplication of band 9q21-q22. It is important to demonstrate inheritance from a phenotypically normal individual in order to differentiate between a variant chromosome and an abnormal chromosome.