PET FDG studies of Wilms tumors

Oral sodium phosphate (NaP) has become an attractive alternative to polyethylene glycol (PEG) for colonic cleansing before colonoscopy, but it potentially has greater complications. This study surveyed members of the Canadian Association of Gastroenterology (CAG) to determine how these colonic lavage agents are used and what complications have been encountered. The Dillman survey technique produced responses from 67% of the 400 members who perform colonoscopy. For the larger out-patient group, respondents used NaP more frequently than PEG (46% versus 35%, respectively, P < 0.015). Respondents used NaP and PEG with similar frequencies for the in-patient group (44% versus 43%). Of respondents using NaP, 45% reported excluding its use in patients with renal failure, 30% with heart disease, 13% with incomplete bowel obstruction and 9% with extreme age. Symptoms suggestive of hypovolemia were reported in 9% of those using NaP compared with 3% using PEG (P < 0.02). Three patients receiving NaP developed acute renal failure. A greater proportion of those using NaP had small unexplained aphthous ulcers (16%) and excessive luminal bubbling (24%) compared with PEG users (3%, P < 0.00001 and 14%, P < 0.03, respectively). These data demonstrate that members of CAG use NaP more frequently than PEG as the colonic lavage solution before colonoscopy. A greater number reported complications with NaP versus PEG, and a significant proportion of the respondents appeared to be unaware of the potential for these complications in specific clinical circumstances.     

Comparison of two bowel preparations for colonoscopy: sodium picosulphate with magnesium citrate versus sulphate-free polyethylene glycol lavage solution

OBJECTIVES: Adequate preparation of the bowel is essential for accurate colonoscopic examination. We compared colonic preparation with sodium picosulphate plus magnesium citrate (SPS-Mg) with sulphate-free polyethylene glycol electrolyte lavage (PEG-EL) solution before colonoscopy, for quality of bowel cleansing, patient discomfort, and side effects. METHODS: Sixty-eight consecutive patients were randomly assigned to receive either 3 sachets of SPS-Mg (16.5 g each) (n = 39) or 3 L of PEG-EL (n = 29) on the day before colonoscopy. Shortly before the procedure each patient was interviewed to determine the degree of discomfort (1 = none or mild, 2 = moderate, 3 = severe) and side effects. The quality of bowel cleansing was graded by a gastroenterologist who was unaware of the method of preparation (from 1 = poor to 4 = excellent). RESULTS: Of the 29 PEG-EL patients, four (14%) did not complete the preparation because of side effects. The degree of discomfort was significantly greater with PEG-EL (mean score, 2.3 +/- 0.7) than with SPS-Mg (mean score, 1.4 +/- 0.5; p < 0.01). Nausea and vomiting were significantly more common in the PEG-EL group (38% vs 13%; p < 0.05). Using intention-to-treat analysis, bowel cleansing proved to be significantly better with SPS-Mg than with PEG-EL (mean score +/- SD, 3.05 +/- 0.9 and 2.57 +/- 1.0, respectively; p = 0.036). CONCLUSIONS: Colonic preparation with SPS-Mg is better tolerated, associated with significantly fewer side effects, and results in higher quality bowel cleansing than preparation with PEG-EL.     

Comparative study of the efficacy and tolerance of 2 types of colon cleansing

OBJECTIVE: To examine if (hypothesis): orally administered colon cleansing with 3 liters of balanced electrolyte/polyethylene glycol solution is superior to the standard method of bowel preparation with senna laxatives and sodium phosphate enemas. Study factors: 1st) Quality of colon cleansing estimated by the attending endoscopist. 2nd) Patient tolerance. METHODS: DESIGN: prospective randomized trial, blind to the endoscopist, comparing two methods of bowel preparation: group A received 3 L of the balanced electrolyte/polyethylene glycol solution the night before the procedure and group B was instructed to ingest 75 ml of a senna laxative the day before the colonoscopy and sodium phosphate enemas per rectum b.i.d. starting 2 days before the examination and again the morning of the procedure. Assessing criteria: 1st) Questionnaire filled by the attending endoscopist immediately after the completion of the colonoscopy. 2nd) Questionnaire filled by the patient the day after the procedure. PATIENTS: Inclusion criteria: all the patients addressed to our Unit for colonoscopy (18 patients refused to participate). Exclusion criteria: severe cardiovascular disease, decompensated diabetes mellitus and severe disease or neurological derangement that prevented collaboration (35 patients). Two hundred and sixteen patients were initially included, 110 in group A and 106 in group B; in 39 patients (18 in group A and 21 in group B) colonoscopy could not be completed for causes others than bowel preparation and were excluded for further evaluation by the endoscopist, thus, quality of bowel preparation was evaluated in 92 patients in group A and in 85 patients in group B; 83 patients (43 in group A and 40 in group B) did not answer the questionnaire, or did it incorrectly, thus, tolerance was evaluated in 67 patients in group A and in 66 patients in group B. RESULTS: In 2 patients in group A (2.2%) and in 9 patients in group B (10.6%) colonoscopy could not be completed because of solid stool (p = 0.045). Mucosal visualization was better in group A than in group B (p = 0.0108). A total of 11.9% of the patients in group A and 25.8% of the patients in group B found the preparation hard or very hard to tolerate (p = 0.0001), patients in this latter group presented more frequently abdominal cramps (p = 0.0004), and distress (p < 0.00001), and dizziness (p = 0.0031). Bad tolerance in group B was primarily due to the rectal enemas (p < 0.0001). CONCLUSIONS: Bowel preparation for colonoscopy with 3 L of orally administer balanced electrolyte/polyethylene glycol solution (PEG) results in a better colon cleansing and is better tolerated than the classical preparation consisting in oral purge and rectal enemas.     

Inadequate control of lipid levels in patients with a previous myocardial infarction

AIM: To access the current lipid management of late survivors of acute myocardial infarction. METHODS: A systematic follow-up of all survivors who had previously been screened for enrolment into one of three randomised clinical trials in Auckland was undertaken from December 1995 to January 1997. All contacted survivors were asked to answer a questionnaire regarding their current therapy and were invited to undergo venepuncture for a lipid assay. RESULTS: Of the 1036 patients with acute myocardial infarction screened for enrolment in the three trials there were 984 (95%) who survived 30 days. At a median of 5.5 years (interquartile range 3.2-8.5) follow-up, 641 (86%) survivors agreed to have a fasting lipid test. The mean total cholesterol level was 5.7 +/- 1.1 mmol/L high density lipoprotein cholesterol 1.1 +/- 0.3 mmol/L, low density lipoprotein cholesterol 3.8 +/- 0.9 mmol/L and triglyceride level 1.9 +/- 1.1 mmol/L. Two hundred and seven (32%) patients were treated with a lipid-modifying agent. Four hundred and forty-five (69%) patients had a cholesterol level > or = 5.2 mmol/L 381 (59%) patients had a level > or = 5.5 mmol/L and 72 (11%) patients had a level > or = 7.0 mmol/L of whom 62 patients were not being treated with a lipid-modifying agent. For the 107 patients with coronary artery bypass grafts, the mean cholesterol level was 5.4 mmol/L and the mean low density lipoprotein cholesterol level was 3.7 +/- 0.9 mmol/L, with 57 (53%) patients not being treated with a "statin" or "fibrate". CONCLUSION: Lipid management is suboptimal in this high risk population of patients post-infarction and greater efforts need to be made to achieve better control. Diet is frequently inadequate in these patients at high risk and statin therapy is indicated.     

Hemodynamic tolerance of intravascular contrast agents for magnetic resonance imaging

RATIONALE AND OBJECTIVES: Intravascular contrast agents for magnetic resonance imaging (MRI) facilitate the quantification of tissue perfusion. The authors determined the hemodynamic tolerance of these agents. METHODS: Doses of 0.05, 0.15, and 0.45 mmol/kg of the polymeric intravascular contrast agent gadolinium-DTPA-polylysine, and di-nitrobenzyl-gadolinium-DTPA, a non-polymeric intravascular contrast agent with high protein binding, and gadolinium-DTPA dimeglumine, a paramagnetic contrast agent with extracellular distribution, were injected into 18 normal male rats as a peripheral intravenous bolus. Systolic, diastolic, and mean blood pressure, left ventricular end-diastolic and developed pressure, positive rate of pressure change (+dP/dt), dP/dt, the rate-pressure product, and heart rate were recorded during a period of 20 minutes. Hemodynamic effects were established by analysis of variance for repeated measurements. RESULTS: There was a transient increase of all blood pressure parameters and contractility for Gd-DTPA-polylysine at the dose of 0.45 mmol/kg only. Di-nitrobenzyl-Gd-DTPA increased blood pressure parameters at 0.45 mmol/kg only. At doses of 0.05 and 0.15 mmol/kg, no significant hemodynamic effects were observed. CONCLUSIONS: The authors conclude that Gd-DTPA-polylysine is hemodynamically safe at doses to 0.15 mmol/kg and acts like a plasma expander at higher doses after peripheral bolus injection in normal rats. Additional investigations are indicated to elucidate the mechanism of a nonsignificant and satiable transient hemodynamic depression after injection of 0.05 mmol/kg DNB-Gd-DTPA.     

Environmental investigation of a legionellosis outbreak in western Sydney: the role of molecular profiling

Colitis following colonoscopy is an acute, self-limited condition characterized by tenesmus and bloody diarrhea appearing within 48 hours of colonoscopy or sigmoidoscopy. Glutaraldehyde used for disinfection of the endoscopes is considered to be the main etiological agent. Three cases of severe acute self-limited colitis are described in this report. All three were observed within one week, and showed the typical anamnestic, clinical, endoscopic, histological, and radiological features of glutaraldehyde-induced colitis. The main characteristics in these cases were the time relationship with colonoscopy and the severity of the clinical presentation, with symptoms of systemic reaction and intense and diffuse edema of the colonic mucosa. The clinical and morphological features may mimic those of colonic ischemia. All three patients recovered completely within a few days, one spontaneously and two after treatment with steroids, antibiotics, and mesalazine. Acute colitis following colonoscopy should be regarded as one of the complications related to colonoscopy, and it should be taken into account in the differential diagnosis of acute colitis.     

Low lipid concentrations in critical illness: implications for preventing and treating endotoxemia

OBJECTIVES: To determine the prevalence and clinical significance of hypolipidemia found in critically ill patients, and whether the addition of a reconstituted lipoprotein preparation could inhibit the generation of tumor necrosis factor-alpha (TNF-alpha) in acute-phase blood taken from these patients. SETTING: Surgical intensive care unit (ICU) of a large urban university hospital. DESIGN: Prospective case series. PATIENTS: A total of 32 patients with a variety of critical illnesses had lipid and lipoprotein concentrations determined. Six patients and six age- and gender-matched control subjects had whole blood in vitro studies of the effect of lipoprotein on lipopolysaccharide mediated TNF-alpha production. INTERVENTIONS: Blood samples were drawn on admission to the ICU and over a subsequent 8-day period. MEASUREMENTS AND MAIN RESULTS: Mean serum lipid and lipoprotein values obtained from patients within 24 hrs of transfer to the surgical ICU were extremely low: mean total cholesterol was 117 mg/dL (3.03 mmol/L), low-density lipoprotein cholesterol 71 mg/dL (1.84 mmol/L), and high-density lipoprotein cholesterol 25 mg/dL (0.65 mmol/L). Only the mean triglyceride concentration of 105 mg/dL (1.19 mmol/L), and the mean lipoprotein(a) concentration of 25 mg/dL (0.25 g/L) were within the normal range. During the first 8 days following surgical ICU admission, there were trends toward increasing lipid and lipoprotein concentrations that were significant for triglycerides and apolipoprotein B. Survival did not correlate with the lipid or lipoprotein concentrations, but patients with infections had significantly lower (p = .008) high-density lipoprotein cholesterol concentrations compared with noninfected patients. Lipopolysaccharide-stimulated production of TNF-alpha in patient and control blood samples was completely suppressed by the addition of 2 mg/mL of a reconstituted high-density lipoprotein preparation. CONCLUSIONS: Patients who are critically ill from a variety of causes have extremely low cholesterol and lipoprotein concentrations. Correction of the hypolipidemia by a reconstituted high-density lipoprotein preparation offers a new strategy for the prevention and treatment of endotoxemia.     

Colonic involvement in ileal Crohn's disease

OBJECTIVES: To determine the risk and predictive factors for colonic extension in patients with ileal Crohn's disease. METHODS: One hundred and fifty patients with ileal Crohn's disease and no specific colonic lesions on initial colonoscopy were studied retrospectively (median follow-up: 51 months). RESULTS: Twelve patients (8%) developed colonic lesions. Ten-year cumulated risks (95% confidence interval) for colonic extension were 17.2% (range: 5.8-28.6) in the whole group, and 22.4% (range: 8.7-36.1) in the group of 86 patients with repeated colonoscopy. Young age at diagnosis was the only factor predicting colonic extension. Seven patients with colonic extension required immunosuppressive therapy but none underwent surgery. CONCLUSION: Ileal Crohn's disease has a low tendency for colonic extension. Colonic extension has no major prognostic implications.     

Can we use erythrocytes for the study of the activity of the ubiquitous Na+/H+ exchanger (NHE-1) in essential hypertension?

Both Na+/Li+ countertransport and electrochemical proton gradient (delta mu(H+))-induced Na+ and H+ fluxes are increased in erythrocytes from patients with essential hypertension. It was assumed that these abnormalities are related to ubiquitous (housekeeping) forms of the Na+/H+ exchanger (NHE-1). To examine this hypothesis, we compared kinetic and regulatory properties of erythrocyte Na+/Li+ countertransport and delta mu(H+)-induced Na+ and H+ fluxes with data obtained for cloned isoforms of the Na+/H+ exchanger. In human erythrocytes, Na+/Li+ countertransport exhibited a hyperbolic dependence on [Na+]0 with a K0.5 of approximately 30 to 40 mmol/L. The activity of this carrier was increased by two-fold in the fraction of erythrocytes enriched with the old cells, was inhibited by 0.1 mmol/L phloretin, and was insensitive to both 1 mmol/L amiloride and ATP depletion. In contrast, delta mu(H+)-induced 22Na influx was exponentially increased at [Na+]0 > 60 mmol/L, was insensitive to phloretin, was partly decreased by both 1 mmol/L amiloride and ATP depletion, and was the same in total erythrocytes and in the old cells. The values of Na+/Li+ countertransport and delta mu(H+)-induced Na+ influx in erythrocytes from different species were not correlating and their ratio in human, rat, and rabbit erythrocytes was 10:1:170 and 1:5:1 for Na+/ Li+ countertransport and delta mu(H+)-induced Na+ influx, respectively. In contrast to the majority of nonepithelial cells and cells transfected with an ubiquitous isoform of Na+/H+ exchanger, both delta mu(H+)-induced Na+ influx and Na+/Li+ countertransport in human erythrocytes were completely insensitive to ethylisopropyl amiloride (20 micromol/L) and cell shrinkage. Thus, our data strongly suggest that human erythrocyte Na+/Li+ countertransport and delta mu(H+)-induced Na+/H+ exchange are mediated by the distinct transporters. Moreover, because the properties of these erythrocyte transporters and NHE-1 are different, it complicates the use of erythrocytes for the identification of the mechanism for activating the ubiquitous form of Na+/H+ exchanger in primary hypertension.     

Clinical relevance of thiamine status amongst hospitalized elderly patients

BACKGROUND: The prevalence and the consequences of thiamine deficiency among elderly patients admitted to acute geriatric wards are not known. OBJECTIVES: (1) To assess the prevalence of thiamine deficiency in patients admitted to a geriatric ward compared to age-matched ambulatory outpatients; (2) to identify their diseases and problems associated with thiamine deficiency, and (3) to determine the relationship between the thiamine status and the cognitive and functional status of these patients. MATERIALS AND METHODS: 118 aged hospitalized patients (83 +/- 7 years; mean age +/- SD) were prospectively enrolled on admission to the geriatric ward. Their cognitive status was assessed using the Mini-Mental State Examination (MMSE) and their ability to perform their activities of daily living (ADL) using ADL scales. The effect of exogenous thiamine pyrophosphate (TPP) addition on the blood transketolase (TK) activity (TPP TK effect) served to estimate thiamine deficiency. Socioeconomic data, diseases and treatment were identified as potential associated risk factors. This group of hospitalized patients was divided according to their thiamine status to characterize the conditions associated with thiamine deficiency. Thirty-five outpatients without any functional or cognitive impairment served as a control group. RESULTS: Of 118 inpatients, 46 (39%) presented with a TPP TK effect of >15%, and 6 with values of >22%, indicating moderate and severe thiamine deficiency, respectively. Only 6 of 30 outpatients (20%) exhibited a TPP TK effect of >15% and none of them reached values of >18%. Although it tended to be lower in outpatients, the mean TPP TK effect did not statistically differ from the mean of inpatients. Thiamine-deficient inpatients comprised a larger proportion of institutionalized subjects than nondeficient inpatients (87 versus 47%, p < 0.001). Functional status, cognitive functions and the occurrence of delirium did not differ according to their thiamine status. By contrast, thiamine-deficient inpatients exhibited a higher proportion of Alzheimer's disease, depression, cardiac failure and falls. Furosemide was more frequently taken by thiamine-deficient patients. CONCLUSIONS: Severe thiamine deficiency remained quite low among the hospitalized elderly. The prevalence of moderate thiamine deficiency approached 40%. Institutionalized subjects were at particular risk of developing thiamine deficiency. Its clinical relevance on functional status and on cognitive function remained not significant. By contrast, a high proportion of falls, Alzheimer's disease, depression, cardiac failure and furosemide use could have been related to thiamine deficiency.     

Hyperlipidaemia in renal transplant patients

OBJECTIVES: The aim of study was to assess the prevalence and severity of hyperlipidaemia in renal transplant patients in a Nordic country. DESIGN: Multicentre, cross-sectional study. SETTING: Outpatients and ward inpatients registered from 23 hospitals covering all regions of the country. SUBJECTS: Renal transplant patients with a functioning graft were registered: 406 patients in all; that is, 43% of the national renal transplant population. All patients used prednisolone, 71% used cyclosporine, either with (51%) or without (20%) azathioprine. Total cholesterol values from general population were obtained from a national survey. MAIN OUTCOME MEASURES: Blood lipids and their relation to clinical parameters. RESULTS: Total cholesterol was significantly higher in transplant patients than in the general population for both genders and all age groups (P < 0.01). Female patients had higher total cholesterol (mean +/- SD: 7.49 +/- 1.61 mmol L(-1)) than males (7.01 +/- 1.55 mmol L(-1); P < 0.001), and also higher HDL cholesterol (1.55 +/- 0.43 vs. males: 1.32 +/- 0.46 mmol L(-1); P < 0.001). Triglycerides were equally elevated in both genders, and 33% had values above 2.2 mmol L(-1). Reduced creatinine clearance, a high body-mass index, female gender, hypertension, and coronary artery disease were independently associated with higher total cholesterol. Beta blockers were associated with lower HDL cholesterol and higher triglycerides, and diuretics with higher triglycerides. Blood lipid levels were not associated with cyclosporine immunosuppression. CONCLUSION: Hyperlipidaemia is prevalent after renal transplantation, and is associated with impaired graft function, hypertension, and with the use of beta blockers and diuretics, but not with the use of cyclosporine.     

Effects of an isotonic oral rehydration solution, enriched with glutamine, on fluid and sodium absorption in patients with a short-bowel

AIM: To compare the effects of a standard oral rehydration solution with a polymeric glucose isotonic solution enriched with glutamine on water and sodium absorption in the short bowel. METHODS: Six patients with high jejunostomy were tested in a random order on 2 consecutive days with the standard solution (20 g/L glucose, 94 mmol/L sodium, 292 mOsm/kg osmolality) and a solution containing maltodextrins (18 g/L Glucidex 12; hydrolysis of 18 g of Glucidex 12 yields 20 g glucose) enriched with 14.6 g/L of glutamine (94 mmol/L sodium, 282 mOsm/kg osmolality). Solutions were administered via a naso-gastric tube at a rate of 2 mL/min. Jejunal effluent for each solution was collected during an 8-h period, after a 14-h equilibrium period. RESULTS: The net 8-h fluid absorption was not significantly different between the standard solution and the solution with glutamine (333 +/- 195 and 213 +/- 251 mL, respectively (mean +/- S.E.M.)). Net sodium absorption was higher for the standard solution than for the solution with glutamine (15 +/- 15 vs. 2 +/- 20 mmol, P < 0.05). The rate of glucose absorption was not different between the solutions. CONCLUSION: The replacement of glucose by maltodextrins and the addition of glutamine to the standard oral rehydration solution, without changing its sodium content or osmolality, results in a reduction of sodium absorption in the short-bowel syndrome.     

Effectiveness of polyethylene glycol antegrade gut lavage bowel preparation for colonoscopy--timing is the key!

PURPOSE: Polyethylene glycol gut lavage is an effective bowel preparation for colonoscopy. The quality of the preparation is not uniform however, and most studies report a rate of suboptimal cleansing of 10 percent or more. One of the possible reasons for a poor preparation is the length of time between the lavage and the examination. The aim of this study was to assess the effect of timing of polyethylene glycol gut lavage on the quality of the preparation achieved. METHODS: Patients referred for elective outpatient colonoscopy with afternoon appointments were randomized to take polyethylene glycol gut lavage either the same morning as their examination (Group 1) or the afternoon of the day before (Group 2). The colonoscopist was unaware of the preparation timing until after the examination was over. During the examination the endoscopist scored the quality of bowel preparation in the cecum, ascending colon, and transverse and left colon. Patient demographics and clinical data were recorded. RESULTS: There were 157 patients in Group 1 (colonoscopy complete in 152 patients) and 160 in Group 2 (colonoscopy complete in 159 patients). The groups were similar in age and gender, indication for colonoscopy, and previous colonic surgery. Patients who drank gut lavage on the morning of their colonoscopy had a greatly better preparation in all areas of the colon than the patients who took their preparation the night before. In the cecum, 97 Group 1 patients had an excellent preparation (vs. 14 Group 2 patients), 45 had a good preparation (vs. 103 Group 2 patients), and 10 had a fair preparation (vs. 33 Group 2 patients). In the ascending colon, numbers of patients with excellent, good, fair, and poor results were 103, 45, 5, and 0 for Group 1 and 12, 107, 32, and 7 for Group 2. Results in the transverse and left colons were 102, 50, 5, 0 and 93, 55, 7, 2 for Group 1 and 15, 116, 27, 5 and 18, 114, 24, 3 for Group 2, respectively. CONCLUSION: The timing of administration of polyethylene glycol-based gut lavage is a major determinant of the quality of the bowel preparation achieved.     

Effects of ginseng treatment on neutrophil chemiluminescence and immunoglobulin G subclasses in a rat model of chronic Pseudomonas aeruginosa pneumonia

OBJECTIVE: To examine the effect of different concentrations of calcium on the contractile responses of isolated strips of rabbit bladder detrusor to various forms of stimulation after 2 h incubation in the presence of substrate and oxygen depletion (in vitro ischaemia), followed by 1 h of recovery. The resultant contractile responses were correlated with the level of lipid peroxidation as determined by malonedialdehyde (MDA) concentration. MATERIALS AND METHODS: Isolated strips of rabbit bladder detrusor smooth muscle were incubated in Tyrode's solution containing different concentrations of calcium (0-5.4 mmol/L). The effect of 2 h of incubation in oxygen- and substrate-free medium (in vitro ischaemia), followed by a 1-h incubation in the presence of oxygen and substrate, on the contractile responses to field stimulation, carbachol and KCl were determined. The effects of repetitive stimulation (15 s of stimulation at 32 Hz applied every 5 min during the 2-h experimental period) were also assessed. RESULTS: The contractile responses to all stimuli increased as the extracellular calcium concentration was increased from 0.6 to 5.4 mmol/L. A 2 h exposure to in vitro ischaemia, followed by a return to normal solution, resulted in a diminished response to all stimuli. This contractile dysfunction was least in the presence of calcium chelator (EGTA) and greatest in the presence of 5.4 mmol/L calcium. Repetitive stimulation during in vitro ischaemia also exacerbated the contractile dysfunction. Lipid peroxidation increased during in vitro ischaemia in proportion to the calcium concentration and was enhanced by repetitive stimulation during this period. Regardless of the incubation conditions, the reduction in the contractile response was significantly greater for field-stimulated tissues than for those stimulated with carbachol or KCl. CONCLUSIONS: These results show that the magnitude of contractile dysfunction induced by incubation in the presence of substrate and oxygen depletion is reduced in the presence of low calcium concentrations, increased in the presence of high calcium levels and increased in the presence of repetitive stimulation. In addition, the level of lipid peroxidation after the recovery period was proportional to the magnitude of contractile dysfunction present.     

Thiolmethyltransferase activity in the human colonic mucosa: implications for ulcerative colitis

Ulcerative colitis is associated with a selective reduction of n-butyrate oxidation by the colonic epithelial cells although the reason for this has been unclear. Colonic epithelial cell n-butyrate oxidation can be inhibited in vitro by incubation with sulphide but the role of mucosal detoxification of sulphide in the metabolic welfare of the colonic mucosa has not been examined. This study aimed to assess the role mucosal detoxification of sulphide by thiolmethyltransferase (TMT)-mediated methylation may play in protecting the healthy colonic mucosa from the adverse effects of luminal sulphide. Colonic epithelial cell suspensions from healthy human proximal (n = 9) and distal colon (n = 10) were incubated in the presence of 14C-labelled n-butyrate (5 mmol/L) alone, butyrate plus sodium hydrogen sulphide (NaHS) (1.5 mmol/L), or butyrate plus NaHS plus S-adenosyl-methionine 1,4 butane disulphonate (SAMe) (5 mmol/L). Study end points were metabolic performance (14CO2 production) and mucosal TMT activity. Incubation with NaHS induced a significant inhibition of 14CO2 production compared with control incubations (P < 0.001) which was similar for proximal and distal colonic cell suspensions. S-adenosyl-methionine 1,4 butane disulphonate reversed this effect completely in proximal but not in distal cell incubations, suggesting a greater susceptibility of the distal colon to the sulphide effect. Although median whole mucosal TMT values did not differ between proximal and distal colonic mucosa, a non-normal distribution of distal TMT values was observed. However, neither the degree of sulphide inhibition of control 14CO2 production nor the degree to which SAMe reversed this inhibition correlated with whole mucosal TMT activity. The study concluded that regional variation exists in TMT activity in the human colon but whilst methylation appears to protect colonic epithelial cells against sulphide-induced inhibition of n-butyrate oxidation, this cannot be directly correlated with mucosal TMT activity.     

Thiamin and riboflavin status of medical inpatients

Thiamin status was assessed by erythrocyte transketolase activity (ETKA) and thiamin pyrophosphate effect (TPPE) and riboflavin status by erythrocyte glutathione reductase activity (EGRA) and activity coefficient (AC) in 165 medical inpatients in Ramathibodi Hospital. Based on TPPE > 15 per cent, 9 per cent of the medical inpatients had thiamin depletion. Most of them were patients with renal, cardiovascular, hematological and infectious diseases. Based on AC > or = 1.2, 17 per cent of these inpatients had riboflavin depletion. Most of them were patients with pulmonary, cardiovascular and hematological diseases. Only one patient with pulmonary disease had both thiamin and riboflavin depletion. The proportion of thiamin depletion (2/37) in subjects with thiamin supplementation (mean 32.4, median 6, mode 2 md/d) tended to be less than those without (9/98). But, subjects with riboflavin supplementation (mean 3.3, median 4, mode 1 md/d) had the proportion of riboflavin depletion (0/31) significantly (Z-test, p < 0.005) lower than without supplementation (23/104). The data suggested that although the usual dose of vitamin supplementation in medical inpatients is beneficial thiamin depletion can still be present in catabolic patients.     

Refractory ascites in cirrhosis: roles of volume expansion and plasma atrial natriuretic factor level elevation

Cirrhotic patients with ascites refractory to diuretics also have blunted response to marked elevations of plasma atrial natriuretic factor levels alone or to moderate intravascular volume expansion by head-out water immersion. However, these patients usually undergo natriuresis after peritoneovenous shunting. To dissect the factors responsible for this response, we studied the effects on separate days of moderate intravascular volume expansion and highly elevated plasma atrial natriuretic factor levels (head-out water immersion and atrial natriuretic factor infusion) or marked volume expansion and moderate plasma atrial natriuretic factor level elevation (head-out water immersion and albumin infusion) in 13 alcoholic cirrhotic patients with massive ascites. Three of these patients, who responded to initial head-out water immersion with a negative sodium balance, served as controls. Unresponsiveness to head-out water immersion was confirmed in the remaining 10 patients on both days on the basis of blunted natriuretic response (urinary sodium excretion < 0.8 mmol/hr after 2 hr). In contrast, these 10 refractory patients were able to achieve negative sodium balance with both combinations. Mean urinary sodium excretion increased from a baseline level of 0.13 +/- 0.10 mmol/hr to a peak level of 2.29 +/- 0.61 mmol/hr after head-out water immersion and atrial natriuretic factor infusion and from 0.10 +/- 0.3 mmol/hr to 1.61 +/- 0.62 mmol/hr after head-out water immersion and albumin infusion. Both maneuvers were associated with suppression of plasma renin activity and serum aldosterone levels. With head-out water immersion and atrial natriuretic factor infusion, we noted a significant increase in 5' cyclic GMP levels, a second messenger of atrial natriuretic factor, indicating possible activation of atrial natriuretic factor receptors at the inner medullary collecting ducts. In contrast, with head-out water immersion and albumin infusion no such increase in levels occurred, indicating that the increase in urinary sodium excretion was mainly due to increased delivery of sodium to the cortical distal nephron, as indicated by a disproportionate increase in urinary potassium excretion. In conclusion, massive (as opposed to moderate) volume expansion or greatly elevated levels of plasma atrial natriuretic factor associated with moderate volume expansion can improve blunted atrial natriuretic factor responsiveness in cirrhotic patients with refractory ascites. This appears to be achieved by way of a marked increase in distal delivery of filtrate in the kidney, with or without activation of distal atrial natriuretic factor receptors in the inner medullary collecting ducts.     

Prospective evaluation of the gastrointestinal tract in patients with iron deficiency and no systemic or gastrointestinal symptoms or signs

BACKGROUND: Although endoscopic evaluation of the gastrointestinal tract is commonly performed to evaluate iron deficiency, little data is available regarding the underlying causes, yield of evaluation, and long-term outcome for those in whom gastrointestinal and systemic symptoms and signs are absent. METHODS: In- or out-patients seen by the gastroenterology consultative service at a large inner-city hospital over a 56-month period were considered eligible for the study when iron deficiency (serum ferritin <50 ng/mL) was documented. Exclusion criteria included: any gastrointestinal or systemic symptoms/signs, radiographic or endoscopic examinations of the gastrointestinal tract within 3 and 5 years, respectively, or obvious source of blood loss. Patients underwent colonoscopy and if no lesions other than carcinoma were found, upper endoscopy was then performed with a pediatric colonoscope. RESULTS: Fifty-two patients were evaluated (mean age, 66 +/- 13 years; range, 20 to 89 years; 32 men/20 women). At the time of evaluation, the mean (+/-SD) hematocrit was 25% +/- 7% (range, 14% to 42%). Overall, 23 patients (44%; 95% CI 30% to 59%) had an identifiable gastrointestinal lesion considered the cause of iron deficiency, including: colonic carcinoma, 11 (21%); colonic and/or esophagogastric/duodenal vascular ectasias, 9 (17%); and gastric carcinoma, colonic polyposis, and colonic ulcers in 1 patient each. Long-term follow-up (median 24 months, range 2 to 63 months) identified only 1 patient with a cause found (colonic carcinoma), and in this patient, complete colonoscopy was not technically possible at the time of initial evaluation. There were no clinical or laboratory features that distinguished patients with an etiology for iron deficiency to the idiopathic group. CONCLUSIONS: Approximately half of patients with iron deficiency in whom gastrointestinal or systemic signs or symptoms are absent have an underlying gastrointestinal lesion. Nevertheless, despite a thorough endoscopic evaluation, some patients will have no etiology found; the prognosis for these patients is excellent.     

Purification and characterization of a cytotoxin from Enterobacter cloacae

OBJECTIVE: To document our evolving surgical management of colonoscopic perforation and examine factors crucial to the improvement of patient care. DESIGN: We conducted a computer-based retrospective analysis of medical records (1980 through 1995). MATERIAL AND METHODS: Among 57,028 colonoscopic procedures performed, 43 patients (0.075%, or 1 perforation in 1,333 procedures) had a colonic perforation. Two additional patients were treated after colonoscopy performed elsewhere. The outcomes analyzed included surgical morbidity and mortality. RESULTS: Twenty-six women and 19 men who ranged in age from 28 to 85 years (median, 69) were treated for colonic perforation. More than 80% of perforations occurred during the latter half of the study period because of the increased volume of colonoscopic procedures (8 perforations among 12,581 examinations from 1980 through 1987 versus 35 perforations among 44,447 colonoscopies from 1988 through 1995). Emergency laparotomy was performed in 42 patients (93%). Perforations occurred throughout the colon: right side = 10; transverse = 9; and left side = 23. Three patients without evidence of peritoneal irritation fared well with nonoperative management. Most patients underwent primary repair or limited resection in conjunction with end-to-end anastomosis. In 14 patients (33%), an ostomy was created. One patient underwent laparotomy without further treatment. Intra-abdominal contamination ranged from none (31%) to local soiling (48%) to diffusely feculent (21%). Postoperative complications occurred in 12 patients and were associated with older age (P = 0.01), large perforations (P = 0.03), and prior hospitalization (P = 0.04). No postoperative deaths occurred. CONCLUSION: Despite a consistently low risk of colonic perforation, the increasing use of colonoscopy in our practice has resulted in an increased number of iatrogenic colonic perforations. In order to minimize morbidity and mortality, prompt operative intervention is the best strategy in most patients. Non-operative management is warranted in carefully selected patients without peritoneal irritation.     

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PURPOSE: To assess the patterns of antimicrobial use, costs of antimicrobial therapy, and medical outcomes by institution in patients with community-acquired pneumonia. PATIENTS AND METHODS: The route, dose, and frequency of administration of all antimicrobial agents prescribed within 30 days of presentation were recorded for 927 outpatients and 1328 inpatients enrolled in the Pneumonia Patient Outcomes Research Team (PORT) multicenter, prospective cohort study. Total antimicrobial costs were estimated by summing drug costs, using average wholesale price for oral agents and institutional acquisition prices for parenteral agents, plus the costs associated with preparation and administration of parenteral therapy. Thirty-day outcome measures were mortality, subsequent hospitalization for outpatients, and hospital readmission for inpatients. RESULTS: Significant variation (P <0.05) in prescribing practices occurred for 17 of the 23 antimicrobial agents used in outpatients across 5 treatment sites, and for 18 of the 20 parenteral agents used in inpatients across 4 treatment sites. The median duration of antimicrobial therapy for treatment site ranged from 11 to 13 days for outpatients (P=0.01), and from 13 to 15 days for inpatients (P=0.49). The overall median cost of antimicrobial therapy was $12.90 for outpatients, and ranged from $10.80 to $58.90 among treatment sites (P <0.0001). The overall median cost of antimicrobial therapy was $228.70 for inpatients, and ranged from $183.70 to $315.60 among sites (P <0.0001). Mortality and hospital readmission for inpatients were not significantly different across sites after adjusting for baseline differences in patient demographic characteristics, comorbidity, and illness severity. Although subsequent hospitalization for outpatients differed by site, the rate was lowest for the site with the lowest antimicrobial costs. CONCLUSION: Variations in antimicrobial prescribing practices by treatment site exist for outpatients and inpatients with community-acquired pneumonia. Although variation in antimicrobial prescribing practices across institutions results in significant differences in antimicrobial costs, patients treated at institutions with the lowest antimicrobial costs do not demonstrate worse medical outcomes.