Histamine-2 receptor antagonists and gastric cancer

We conducted a case-control study at Group Health Cooperative of Puget Sound to evaluate the relation between longterm histamine-2 (H2) receptor antagonist use and gastric cancer. We identified 113 cases and 452 controls and estimated a relative risk (RR) of 2.0 [95% confidence interval (C1) = 1.0-3.9]. When we evaluated the effect of time-since-first-use, the RR estimates were 6.5, 1.2, and 1.0 for 2-4 years of use, 5-9 years, and > or = 10 years, respectively. The data provide substantial evidence that long-term H2 antagonist use is not associated with gastric cancer.

Detection of duodenal fluid in the oesophagus with a sodium ion selective electrode

The assessment of duodeno-oesophageal reflux is difficult as, until recently, no technique has been readily available for continuous ambulatory monitoring. A sodium ion selective electrode placed in the stomach has been previously shown to detect duodenogastric reflux by using sodium as a marker. This relies on the difference in sodium concentration between gastric (5-60 mmol/L) and duodenal, biliary and pancreatic (150 mmol/L) fluids. In this pilot study to assess the efficacy of the electrode in the distal oesophagus, eight subjects without symptomatic gastro-oesophageal reflux and eight subjects with known duodenogastric reflux were studied. Thirty millilitre volumes of varying sodium solutions (40, 80, 100 and 140 mmol/L) were swallowed to assess the response of the electrode to sodium ions. In both groups, this revealed a constant and reproducible rise in response with increasing concentration (P < 0.0001). The stomachs of subjects with duodenogastric reflux were aspirated via a nasogastric tube to obtain 12 different samples of gastric fluid. This was assayed for sodium and bile acid concentration. The fluid was then reinfused as a 30 mL bolus into the oesophagus through a tube to simulate oesophageal reflux. A rise equivalent to 40-72 mmol/L Na+ was recorded by the electrode in response to samples that contained 58-81 mmol/L Na+ and 0.4-16 mmol/L bile acids, recorded by quantitative analysis, and a response of up to 20 mmol/L Na+ was recorded by the electrode to sodium concentrations < 49 mmol/L and bile acid concentrations of 0.005-0.6 mmol/L. The response was appropriate to the assayed bile acid concentration in all but one sample. The sodium ion selective electrode responds to bile containing fluids introduced into the oesophagus. Further investigation is warranted to determine its ability to measure duodeno-oesophageal reflux continuously.

Randomised, prospective, single-blind comparison of laparoscopic versus small-incision cholecystectomy

BACKGROUND

We report a prospective randomised comparison between laparoscopic and small-incision cholecystectomy in 200 patients which was designed to eliminate bias for or against either technique.

METHODS

Patients were randomised in the operating theatre and anaesthetic technique and pain-control methods were standardised. Four experienced surgeons did both types of procedure. Identical wound dressings were applied in both groups so that carers could be kept blind to the type of operation.

FINDINGS

There was no significant difference between the groups for age, sex, body mass index, and American Society of Anaesthesiologists grade. Laparoscopic cholecystectomy took significantly longer than small-incision cholecystectomy (median 65 [range 27-140] min vs 40 [18-142] min, p<0.001). The operating time included operative cholangiography which was attempted in all patients. We found no significant difference between the groups for hospital stay (postoperative nights in hospital, median 3-0 [1-17] nights for laparoscopic vs 3-0 [1-14] nights for small-incision, p=0.74), time back to work for employed persons (median 5-0 weeks vs 4.0 weeks; p=0.39), and time to full activity (median 3-0 weeks vs 3.0 weeks; p=0.15).

INTERPRETATION

Laparoscopic cholecystectomy takes longer to do than small-incision cholecystectomy and does not have any significant advantages in terms of hospital stay or postoperative recovery.

Potential mechanisms by which nonsteroidal anti-inflammatory drugs elevate blood pressure: the role of endothelin-1

To determine whether endothelin-1 (ET-1) contributes to hypertension associated with non-steroidal anti-inflammatory drug (NSAID) usage in healthy, elderly, normotensive individuals a randomised, double-blind, placebo-controlled, crossover trial of indomethacin was undertaken in 41 healthy, elderly individuals with stable normotension or controlled hypertension (blood pressure (BP) < or = 160/90 mm Hg). The main outcome measures were systolic and diastolic BP, heart rate, cardiac output, weight, creatinine clearance, plasma renin activity, aldosterone, endothelin-1 and arginine vasopressin concentrations and 24 h urinary endothelin-1 and 6 keto prostaglandin F1 alpha outputs. Analysis of covariance was used to evaluate the effect of indomethacin on BP and related parameters. Indomethacin treatment for 1 month increased systolic (+/- s.e.m.: 4.1 +/- 2.2 mm Hg; 95% confidence interval 0 to 8.3 mm Hg) and diastolic BP (2.7 +/- 1.1 mm Hg; 0.4 to 4.9 mm Hg) without altering cardiac output (P = 0.59), implying an increase in total peripheral resistance. Indomethacin treatment produced a small increase in weight (1.4 +/- 0.4 kg; 0.6 to 2.2 kg), a small reduction in renal function (creatinine clearance: 6.8 +/- 1.8 mis/min; 3.3 to 10.3 mis/min) but a significant (83%) increase in daily urinary endothelin-1 production (13.1 +/- 3.4 ng/ml; 6.4 to 19.8 ng/ml) without altering plasma ET-1 concentration, suggesting increased renal synthesis. In conclusion, renal paracrine effects of ET-1 may contribute to NSAID-induced blood pressure elevation in humans.

In vitro contractility of stimulated and non-stimulated human gallbladder muscle

In an attempt to define, more clearly, the nature of gallbladder contraction we obtained muscle strips from human gallbladder wall, removed at cholecystectomy. Samples were taken from various areas of the gallbladder to seek evidence of a dominant axis of contraction. The strips were stimulated with increasing concentrations of cholecystokinin-8 (CCK-8) and carbachol, and, to determine maximal contractile force, 0.25 M potassium chloride. No differences were seen between samples taken from the long-itudinal, circular and oblique axes. In a second series of experiments, samples were taken from the body and neck regions of the gallbladder. In these, it was seen that the samples from the body contracted more forcefully than those of the neck tissue and that they were more sensitive to carbachol stimulation. The difference in response to CCK-8 measured in the strips from the body and cystic duct/neck of the gallbladder cannot be explained by a difference in sensitivity to CCK-8, but is mainly due to the difference in the amount of muscle tissue present. Strips from the body are more sensitive to muscarinic stimulation that those from the neck. Overall, there is a functional difference in sensitivity between the body and neck which would serve to facilitate bile flow into the common bile duct during gallbladder contraction.

I/D polymorphism of the angiotensin-converting enzyme gene does not predict isolated systolic or systolic-diastolic hypertension in the elderly

To determine whether insertion/deletion (I/D) polymorphism (intron 16) of the angiotensin converting-enzyme (ACE) gene is associated with isolated systolic hypertension (ISH: systolic blood pressure (BP) > or = 160, diastolic BP < 90 mm Hg) or systolic-diastolic hypertension (S-D hypertension: diastolic BP > or = 90 +/- systolic BP > or = 160 mm Hg) compared with normotensive controls (systolic BP < 160, diastolic BP < 90 mm Hg), we conducted a case-control study of 733 non-institutionalised, elderly (> or = 60 years) residents of Dubbo, NSW. Individuals were classified as: ISH (n = 167), S-D hypertension (n = 207) and normotensive control (n = 359) with age and sex matching. II, DD and ID genotypes were determined by a nested PCR strategy using DNA extracted from serum. The frequencies of D and I alleles in the control population (0.70 and 0.30 respectively) were not significantly different in the ISH group or the S-D hypertension group (chi 2: 1.7, P = 0.42). After adjustment for several potential confounders, neither genotype nor allele predicted ISH (II vs DD: odds ratio (OR): 1.06, 95% confidence interval (CI): 0.55-2.03; I vs D: 1.09, 0.82-1.46) or S-D hypertension (II vs DD: 1.19, 0.67-2.10; I vs D: 1.16, 0.89-1.52) in this elderly cohort. The I/D polymorphism of the ACE gene is not a marker for either form of hypertension in this large elderly sample.

The value of abdominal exploration during cholecystectomy

With the advent of 'minimal access' cholecystectomy patients no longer have an exploratory laparotomy at the time of the operation and it is possible that relevant pathology may be missed as a result. This study analyses the findings at exploratory laparotomy in 223 patients undergoing open cholecystectomy. Forty-two patients (19%) were found to have incidental pathology but in only three (1.3%) did this lead to additional operative procedures. We therefore conclude that the loss of exploratory laparotomy at cholecystectomy does not have a significant detrimental effect on patient care.

Conflicting demands in surgical practice

975 Fellows of the Association of Surgeons of Great Britain and Ireland were circulated with a questionnaire which was designed to assess the extent to which they experienced conflicts between personal, clinical and administrative demands. Seventy-one per cent of the 305 respondents indicated that they had experienced such conflicts within the previous three weeks. When a conflicts between administrative and clinical demands was experienced, surgeons gave priority to each in similar proportions, but when personal or family needs conflicted with clinical or administrative demands, their personal lives were almost always given a lower priority. The surgeons reported that these types of conflict often affected the quality of patient care and 60 per cent indicated that they were considering early retirement.

Non-steroidal anti-inflammatory drugs

The elderly are at higher risk of adverse reactions from non-steroidal anti-inflammatory drugs (NSAIDs), including those due to drug interactions, than younger people. Before prescribing oral NSAIDs in the elderly, the clinician should consider other forms of therapy and topical NSAIDs. When an oral NSAID is used, the dose should be minimised and the need for treatment reviewed periodically to reduce duration of therapy. NSAIDs with a high risk of toxicity (such as phenylbutazone, salicylates, piroxicam and indomethacin) should be avoided in the elderly.

Reversal of lipopolysaccharide-analog-induced antibody suppression by anti-transforming growth factor beta and indomethacin

Monophosphoryl lipid A and a synthetic, nontoxic monosaccharide analog of lipid A, termed GLA 60, both strongly suppressed antibody production when administered 1 to 2 days prior to antigen. Evidence is presented that this suppression was mediated by two cytokines, prostaglandin E and transforming growth factor beta, because it was reversed by multiple injections of the cyclooxygenase inhibitor indomethacin and by in vitro addition of antibody to transforming growth factor beta.

Evaluation and comparison of the TDxII, Stratus, and OPUS digoxin assays

Three automated immunoassays for digoxin in serum were evaluated--Abbott TDxII, Baxter Stratus, and Behring OPUS. The accuracy and precision of the assays were assessed by weighed-in controls and an external quality control program. Coefficients of variation of all methods in serum were < or = 10% at weighed-in concentrations of digoxin of 1 and 2.5 micrograms/L. Accuracy relative to weighed-in concentrations of 1 and 2.5 micrograms/L ranged from 98 to 126% for all methods. Comparative results from patient samples showed little difference between the TDxII and Stratus and a greater difference observed between the TDxII and OPUS assays. The detection of digoxin-free samples containing digoxin-like immunoreactive substances (DLIS) in neonatal cord blood, pregnant patients, and liver and renal recipients by each assay was then assessed. The TDxII exhibited the highest incidence of DLIS. This is evident in neonatal cord blood in which 40.4% of samples tested positive. In comparison, the extent of DLIS detected by Stratus was less and OPUS exhibited no DLIS in any of the groups studied. A case study of a patient treated with anti-digoxin Fab fragments (Digibind) also was included for analysis by each method. Fourteen hours after Digibind administration, the TDxII registered a digoxin concentration of 49.5 micrograms/L compared with 3.73, 1.80, and 2.49 micrograms/L for Stratus, OPUS, and ultrafiltered TDxII methods, respectively. The results indicate that to determine the concentration of digoxin after the administration of Digiband, the OPUS or fluorescence polarization immunoassay (FPIA)-ultrafiltered samples by TDxII are the assays of choice.

Applied potential tomography in the measurement of gastric emptying in infants

The aim of this study was to investigate the feasibility of using applied potential tomography (APT), a noninvasive and nonradioactive method, to measure the rate of gastric emptying in preterm babies and infants < 3 months old. APT, a form of electrical impedance tomography, creates tomographic images of tissue resistivity to a small electrical current and has been used to study gastric emptying in adults. The rate of gastric emptying of 53 preterm infants and 29 term infants was measured. The test feed was either milk (formula milk or expressed breast milk) or Dioralyte (a commercial rehydration solution). When a nasogastric tube was present, the results obtained by APT were validated by comparing the volume of feed estimated to be present with the volume that could be aspirated. All infants completed the investigation without any problems. APT demonstrated a slower rate of emptying of milk feeds than Dioralyte and showed that milk and Dioralyte feeds in preterm babies emptied at a similar rate to feeds in term infants. In validation studies, gastric emptying has been observed in 44 of 47 studies, and this finding was confirmed by aspiration of the nasogastric tube. Applied potential tomography is a safe, noninvasive method for measuring gastric emptying in small infants.

Effects of piezoelectric lithotripsy on human DNA

Genomic DNA was extracted from excised gallbladder mucosa, obtained shortly after a single treatment piezoelectric lithotripsy. Control samples were obtained from age and sex-matched patients who had received no lithotripsy. No DNA fragmentation was demonstrable on agarose gel electrophoresis. Suspensions of cultured lymphoblasts were subjected to different shock wave doses and the percentage of cells surviving the treatment was assessed immediately and the rate of cell death monitored over the following 7 h. The proportion of cells surviving the treatment decreased with increasing shock wave doses, but subsequent rate of cell death was no different from controls. DNA, extracted from the intact surviving cells, again showed no evidence of fragmentation on electrophoresis, but the DNA extracted from the supernatant showed extensive fragmentation.

NSAID-related adverse drug interactions with clinical relevance. An update

The prevalence and incidence of adverse drug interactions involving NSAIDs remain unknown. To identify those proposed drug interactions of greatest clinical significance, it is appropriate to focus on interactions between commonly used and/or commonly coprescribed drugs, interactions for which there are numerous well documented case reports in reputable journals, interactions validated by well designed in vivo human studies and interactions affecting high-risk drugs and/or high-risk patients. While most interactions between NSAIDs and other drugs are pharmacokinetic, NSAID-related pharmacodynamic interactions may be considerably more important in the clinical context. However, prescriber ignorance is likely to be a major determinant of many adverse drug interactions. Adverse drug interactions involving NSAIDs may be restricted by rational prescribing and by careful monitoring, particularly high-risk patients, drugs and therapy periods. Prescribing NSAIDs is relatively contra-indicative for patients on oral anticoagulants due to hemorrhage and for patients taking high dose methotrexate due to bone marrow toxicity, renal failure and hepatic dysfunction. Combination NSAID therapy cannot be justified since toxicity may be increased without any improvement in efficacy. Where lithium or antihypertensives are coprescribed with NSAIDs, aspirin or sulindac are preferred and close monitoring is mandatory for lithium toxicity and hypertension respectively. Phenytoin or oral hypoglycemic agents may be administered with NSAIDs other than pyrazoles and salicylates, provided, the patients are monitored carefully at the initiation and cessation of NSAID treatment. Digoxin, aminoglycosides and probenecid may be coprescribed with NSAIDs but close monitoring is required, particularly for high-risk patients such as the elderly. Indomethacin and triamterine should be avoided due to the risk of renal failure, high dose aspirin should be replaced by naproxen in patients on sodium valproate and care is required when corticosteroids are administered to patients taking salicylates long term in high dosage. Interactions between NSAIDs and antacids or cholestyramine are generally avoidable by administering these drugs at different times.

Long-term results of highly selective vagotomy: a prospective study with implications for future laparoscopic surgery

Between 1979 and 1984, 141 patients (110 men, 31 women) underwent highly selective vagotomy (HSV) by a standard open technique for duodenal ulcer. All patients had received preoperative treatment with full-dose H2-receptor antagonists. Some 107 of these patients underwent HSV for persistent relapse on withdrawal of H2-receptor antagonists (relapsing responders) and 30 because of non-response to such drugs. After 4 years of follow-up, non-responders were found to be more likely to have symptoms after operation (P < 0.001), but did not have a higher rate of recurrent ulceration. At a median of 11 (range 8-14) years after operation 126 patients were still alive; 115 (91 per cent) of these were followed up. Ten patients (9 per cent) were found to have had endoscopically proven recurrence and eight (7 per cent) still had symptoms without evidence of recurrence. The endoscopic recurrence rate and symptom rate at 11 years were no longer significantly different between relapsing responders and non-responders. The preoperative response to H2-receptor antagonist therapy does not help in predicting the likelihood of ulcer recurrence or long-term symptoms after HSV. Post-operative symptoms do not necessarily predict long-term ulcer recurrence. The long-term endoscopic recurrence rate after HSV is low and, if equally good results can be obtained laparoscopically, this will be an important and cost-effective option in the management of duodenal ulcer.

Cost effectiveness of adjuvant bile salt treatment in extracorporeal shock wave lithotripsy for the treatment of gall bladder stones

The relative cost effectiveness of adjuvant urso and chenodeoxycholic acid treatment in extracorporeal shockwave lithotripsy (ESWL) has been assessed as part of a pragmatic randomised controlled trial of ESWL as a treatment of gall bladder stones. Of the first patients with gall stone volume < 4 cm3 randomised to ESWL in the main trial, 24 were randomised to have ESWL alone and 26 to have adjuvant bile acid treatment, one of whom died before the end of the 12 month follow up period. At 12 months after treatment, differences in gall stone clearance between ESWL alone (3/24 (13%) clear, 5 (21%) referred for surgery) and ESWL and bile acids (6/25 (24%) clear, 2 (8%) referred for surgery) were not significant (p = 0.36, log rank test). Patients in both groups had substantial and significant health gains (according to biliary pain frequency and severity, Nottingham Health Profile scores, visual analogue scale symptom scores, and complications) but there were no significant differences between the groups. Improvements in both groups usually occurred within a few weeks of treatment and were unrelated to gall stone clearance. Costs were greater in the bile salt group (95% confidence intervals for estimated cost difference: 90 pounds to 630 pounds). If the purpose of treatment is symptom relief rather than gall stone clearance then adjuvant bile salt treatment seems to be unnecessary.