Implementing Alfred60AST in a clinical lab: Clinical impact on the management of septic patients and financial analysis

INTRODUCTION

Sepsis is an important cause of morbidity and mortality. An accelerated microbiology diagnosis is crucial in order to reduce the time to initiate targeted antibiotic therapy. The Alfred60AST system is able to provide phenotypic Antimicrobial Susceptibility Testing (AST) results within hours. This study has two objectives: assess the clinical impact of this technology and determine its cost-effectiveness.

METHODS

During a ten-week period, all new enterobacterial or enterococcal bloodstream infection was analyzed with the Alfred60AST system, in parallel with routine methods. Its impact on the clinician's therapeutic strategy was studied. In order to assess the financial and practical aspects of the method, an analysis of the extracosts and a survey of the technical staff were conducted.

RESULTS

Fifty-three cases of bacteriemia were included. For the Enterobacteriaceae bacteriemias, a clinical impact was shown in 18.9% of the cases (e.g, treatment modification). The financial analysis highlighted an increase in costs (+38% for Enterobacteriaceae, +50% for Enterococci), compared to the theoretical costs reported by the firm, due to the workflow and the volumes of samples used. Finally, results of the technical staff survey were favorable in terms of ease of use of the system.

CONCLUSION

In addition to its ease of use, the Alfred60AST system is able to provide an AST in a record time. This study shows a real interest of the technique in the therapeutic management of patients with enterobacterial sepsis. However, its routine implementation requires an increase of the analyzed volumes as well as a 24/7 organization of the laboratory in order to be profitable.

Hydroxyl radical adduct of 5-aminosalicylic acid: a potential marker of ozone-induced oxidative stress

The use of 5-aminosalicylic acid in assessment of reactive oxygen species formation was investigated by in vitro Fenton and ozonation reactions, and by in vivo ozone-exposure experiments. Enzymatic hydroxylation was evaluated by a microsomal assay. Fischer 344 male rats (250 g) injected with 5-aminosalicylic acid (100 mg x kg(-1) i.p.; 30 min) were exposed to ozone (0, 1, 2 ppm; nose only, 2 h); bronchoalveolar lavage, lung homogenates, and plasma were recovered. Oxidation products of 5-aminosalicylic acid were as follows: salicylic acid, by deamination; 2,3-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid, from radical or enzymatic hydroxylation; 5-amino-2-hydroxy-N,N'-bis(3-carboxy-4-hydroxyphenyl)-1,4-benzoquinonediimine, a condensation product of oxidized 5-aminosalicylic acid; and 5-amino-2,3,4,6-tetrahydroxybenzoic acid, attributed to hydroxyl radical attack without deamination, identified by HPLC electrochemical (HPLC-EC) detector system analysis and by GC-MS analysis of trimethylsilyl derivatives. 5-Aminotetrahydroxybenzoic acid was not formed enzymatically. 5-Aminotetrahydroxybenzoic acid, but not 5-aminosalicylic acid, was significantly elevated in bronchoalveolar lavage (+86%) and lung homogenates (+56%) in response to 2 ppm ozone (p < 0.05); no significant changes were detected in plasma. The data indicate that hydroxylation of 5-aminosalicylic acid is a potential specific probe for in vivo oxidative stress.

Multi-center study of two dose levels of paclitaxel with carboplatin in locally advanced and metastatic non-small cell lung cancer (NSCLC)

BACKGROUND

The efficacy and toxicity of the combination of two cytotoxic compounds that are active as single agents in non-small cell lung cancer (NSCLC), paclitaxel (Taxol) and carboplatin (Paraplatin) was investigated in a multicenter, community-based setting.

MATERIALS AND METHODS

Two consecutive cohorts of chemonaive patients with stages IIIA/B and IV NSCLC received two dose levels of paclitaxel. The first cohort received 200 mg/m2 over 3 hours (HD) and the second cohort 175 mg/m2 over 3 hours (LD) in combination with a fixed dose of carboplatin. The dose of carboplatin was calculated according to the Calvert formula with an area under the concentration versus time curve (AUC) value of 6 mg/ml/minute. The carboplatin clearance, calculated by the Chatelut formula rather than the glomerulation filtration rate (GFR) +25, was introduced into the Calvert formula. The eligibility criteria were identical for both cohorts throughout the study. Treatment was administered every three weeks. The study endpoints were response rate (RR), toxicity, time to progression (TTP) and survival (S).

RESULTS

One hundred and thirty consecutive eligible patients from 36 Belgian institutions were fully evaluable for all study parameters (99 in the HD and 31 in the LD cohort). Myelosuppression was the most prominent side-effect of treatment with comparable results for both cohorts. The worst grade 3-4 leucopenia and neutropenia per patient in the HD versus LD cohort was 34.4 vs 19.3% and 59.2 vs 51.6%, respectively. 10.4% of patients in the HD cohort required hospitalisation for febrile neutropenia (6.2% with and 4.2% without documented bacterial infection), while in the LD cohort the respective figures were 13.7, 10.3 and 3.4%. The most prominent non-hematologic toxicities were alopecia and polyneuropathy, with no major difference between the HD and LD cohort (grade 2 alopecia in 78.1 vs. 83.9% and grade 3 neuropathy in 14.3 vs. 9.7%, respectively). The overall best clinical RR was 31 out of 130 (23.8%) with one complete (CR) and 30 partial responses (PR). The respective RR in the HD and LD cohort was 23.2 and 25.8%. Median TTP and S for all patients was 120 and 248 days, with no apparent difference between the HD and the LD cohort (119 and 254 versus 128 and 222, respectively). The one year survival was 34% in the HD cohort. The 95% confidence intervals for efficacy and toxicity parameters overlapped in both cohorts.

CONCLUSION

In this multicenter study, the combination of paclitaxel and carboplatin produced a moderate RR of 23.8% in stages IIIA/B & IV NSCLC. The therapy was generally well tolerated at both doses of paclitaxel. Myelosuppression, neurotoxicity and alopecia were the major therapy-related side-effects. The differences between the two paclitaxel dose cohorts with respect to activity and toxicity were minimal. The use of the Chatelut formula to calculate the carboplatin clearance is feasible, but might have lead to the apparent excess in myelotoxicity in our study compared to other studies which used other methods for estimating renal function.

Biliopancreatic diversion (doudenal switch procedure)

The physiological principle underlying biliopancreatic diversion (BPD) is attractive. It decreases food absorption and particularly that of fat. It preserves normal eating habits and is compatible with a good quality of life. Because weight loss is not a function of an imposed aversion to eating, it is more appealing to patients. Data are accumulating showing that BPD can permanently cure morbid obesity in a majority of patients and is remarkably well tolerated. While long-term systemic side-effects from decreased absorption continue to raise concerns, available results have already shown that, within 20 years, metabolic disturbances are well tolerated while weight loss and quality of life are maintained. Vitamin and mineral replacement therapy and periodic monitoring are essential. The original procedure described by Scopinaro with subsequent modifications will be presented, focusing on the duodeno-ileal switch procedure.

Evidence for the lack of base-change and small-deletion mutation induction by trichloroethylene in lacZ transgenic mice

Trichloroethylene (TCE) is a widely used industrial solvent employed mainly for degreasing and cold-cleaning metal parts. It is also used for dry cleaning, and in the production of a number of chemical products. It has been shown to induce liver and lung tumors in rodents, and have a variety of positive and negative results using in vitro and in vivo mutagenicity tests. In order to assist in the interpretation of the mechanism of carcinogenicity, TCE was tested for the ability to induce gene mutations and small deletions using the lacZ transgenic mouse model (MutaMouse). Male and female animals were exposed by inhalation to 0, 203, 1153, and 3141 ppm TCE, 6 h per day for 12 days. 14 and 60 days following the last exposure, animals were sacrificed and the mutation frequency in bone marrow, kidney, spleen, liver, lung, and testicular germ cells determined. The results of this study indicate that TCE did not induce base-change or small-deletion mutations as detected in this assay in any of the tissues examined. Environ. Mol. Mutagen. 34: 190-194, 1999. Published 1999 Wiley-Liss, Inc.

Acute effects of inhaled urban particles and ozone: lung morphology, macrophage activity, and plasma endothelin-1

We studied acute responses of rat lungs to inhalation of urban particulate matter and ozone. Exposure to particles (40 mg/m3 for 4 hours; mass median aerodynamic diameter, 4 to 5 microm; Ottawa urban dust, EHC-93), followed by 20 hours in clean air, did not result in acute lung injury. Nevertheless, inhalation of particles resulted in decreased production of nitric oxide (nitrite) and elevated secretion of macrophage inflammatory protein-2 from lung lavage cells. Inhalation of ozone (0.8 parts per million for 4 hours) resulted in increased neutrophils and protein in lung lavage fluid. Ozone alone also decreased phagocytosis and nitric oxide production and stimulated endothelin-1 secretion by lung lavage cells but did not modify secretion of macrophage inflammatory protein-2. Co-exposure to particles potentiated the ozone-induced septal cellularity in the central acinus but without measurable exacerbation of the ozone-related alveolar neutrophilia and permeability to protein detected by lung lavage. The enhanced septal thickening was associated with elevated production of both macrophage inflammatory protein-2 and endothelin-1 by lung lavage cells. Interestingly, inhalation of urban particulate matter increased the plasma levels of endothelin-1, but this response was not influenced by the synergistic effects of ozone and particles on centriacinar septal tissue changes. This suggests an impact of the distally distributed particulate dose on capillary endothelial production or filtration of the vasoconstrictor. Overall, equivalent patterns of effects were observed after a single exposure or three consecutive daily exposures to the pollutants. The experimental data are consistent with epidemiological evidence for acute pulmonary effects of ozone and respirable particulate matter and suggest a possible mechanism whereby cardiovascular effects may be induced by particle exposure. In a broad sense, acute biological effects of respirable particulate matter from ambient air appear related to paracrine/endocrine disruption mechanisms.

Biliopancreatic diversion with duodenal switch

In 1990 Scopinaro's technique of biliopancreatic diversion with distal gastrectomy (DG) and gastroileostomy was modified. A sleeve gastrectomy with duodenal switch (DS) was used instead of the distal gastrectomy; and the length of the common channel was made 100 cm instead of 50 cm. A questionnaire and a prescription for blood work were sent to 252 patients who underwent DG a mean 8.3 years ago (range 6-13 years) and 465 patients who underwent DS 4.1 years ago (range 1.7-6.0 years). The questionnaire response rate was 93%, and laboratory work was completed for 65% of both groups. The mean weight loss after DG was 37 +/- 21 kg and after DS 46 +/- 20 kg. There were fewer side effects after DS: The number of daily stools was lower (p < 0.0002), as was the prevalence of diarrhea (p < 0.01), vomiting (p < 0.001), and bone pain (p < 0.001). Greater benefits related to several aspects of life were reported after DS than DG (p < 0.0001). The mean serum levels of ferritin, calcium, and vitamin A were higher (p < 0.001), and parathyroid hormone was lower. The yearly revision rate for excessive malabsorption was 1.7% per year after DG and 0.1% per year after DS. The two procedures were equally efficient for treating co-morbid conditions such as diabetes, hypertension, and hypercholesterolemia. Biliopancreatic diversion with sleeve gastrectomy/duodenal switch and a 100-cm common limb was shown to produce greater weight loss with fewer side effects.

Inhalation toxicity of methanol/gasoline in rats: effects of 13-week exposure

The subchronic inhalation toxicity of a methanol/gasoline blend (85% methanol, 15% gasoline, v/v) was studied in rats. Sprague Dawley rats (10 animals per group) of both sexes were exposed to vapours of methanol/gasoline at 50/3, 500/30 and 5000/300ppm for 6 hours per day, 5 days per week, for 13 weeks. Control animals inhaled filtered room air only. Control recovery and high dose recovery groups were also included which inhaled room air for an extra 4 weeks following the treatment period. No clinical signs of toxicity were observed in the treatment group and their growth curves were not significantly different from the control. Except for decreased forelimb grip strength in high dose females, no treatment-related neurobehavioural effects (4-6 hours post inhalation) were observed using screening tests which included cage-side observations, righting reflex, open field activities, and forelimb and hindlimb grip strength. At necropsy, the organ to body weight ratios for the liver, spleen, testes, thymus and lungs were not significantly different from the control group. There were no treatment-related effects in the hematological endpoints and no elevation in serum formate levels. Minimal serum biochemical changes were observed with the only treatment-related change being the decreased creatinine in the females. A dose-related increase in urinary ascorbic acid was detected in males after 2, 4 and 8 weeks of exposure, but not after the 12th week, and in females only at week-2. Increased urinary albumin was observed in treated males starting at the lowest dose and at all exposure periods, but not in females. A treatment-related increase in urinary beta 2-microglobulin was detected in males at week-2 only. Except for mild to moderate mucous cell metaplasia in nasal septum B, which occurred more often and with a slightly higher degree of severity in the low dose groups of both sexes, and presence of a minimal degree of interstitial lymphocyte infiltration in the prostate glands in the high dose males. No other significant microscopic changes were observed in the tissues of treated animals. Based on the marked increase in urinary ascorbic acid and albumin in the high dose males and the decreased forelimb grip strength in the high dose females, we concluded that the no-observed adverse effect level (NOAEL) of methanol/gasoline vapour is 500/30 ppm.

Acute pulmonary toxicity of urban particulate matter and ozone

We have investigated the acute lung toxicity of urban particulate matter in interaction with ozone. Rats were exposed for 4 hours to clean air, ozone (0.8 ppm), the urban dust EHC-93 (5 mg/m3 or 50 mg/m3), or ozone in combination with urban dust. The animals were returned to clean air for 32 hours and then injected (intraperitoneally) with [3H]thymidine to label proliferating cells and killed after 90 minutes. The lungs were fixed by inflation, embedded in glycol methacrylate, and processed for light microscopy autoradiography. Cell labeling was low in bronchioles (0.14 +/- 0.04%) and parenchyma (0.13 +/- 0.02%) of air control animals. Inhalation of EHC-93 alone did not induce cell labeling. Ozone alone increased (P < 0.05) cell labeling (bronchioles, 0.42 +/- 0.16%; parenchyma, 0.57 +/- 0.21%), in line with an acute reparative cell proliferation. The effects of ozone were clearly potentiated by co-exposure with either the low (3.31 +/- 0.31%; 0.99 +/- 0.18%) or the high (4.45 +/- 0.51%; 1.47 +/- 0.18%) concentrations of urban dust (ozone X EHC-93, P < 0.05). Cellular changes were most notable in the epithelia of terminal bronchioles and alveolar ducts and did not distribute to the distal parenchyma. Enhanced DNA synthesis indicates that particulate matter from ambient air can exacerbate epithelial lesions in the lungs. This may extend beyond air pollutant interactions, such as to effects of inhaled particles in the lungs of compromised individuals.

Laparoscopic Roux-en-Y gastric bypass for morbid obesity: a feasibility study in pigs

According to randomized prospective studies in humans, the Roux-en-Y gastric bypass provides more effective weight loss than vertical banded gastroplasty for morbid obesity. Ten pigs underwent laparoscopic Roux-en-Y gastric bypass to assess the feasibility of this procedure with conventional laparoscopic techniques and instruments. The procedure took an average of 4 h 20 min. Of the first five pigs killed immediately, four had correct anastomoses. Of the five remaining pigs with postoperative follow-up, three survived with an intact anastomosis and staple line at autopsy. Two died within 48 h, one from peritonitis (perforation of the small bowel), the other from unknown causes. A definite learning curve exists for this procedure primarily because of the extent of gastrointestinal reconstruction, but there is potential for it to be used in humans.

Management of intra-abdominal infections. The case for intraoperative cultures and comprehensive broad-spectrum antibiotic coverage. The Canadian Intra-abdominal Infection Study Group

OBJECTIVE

To test the hypothesis that comprehensive broad-spectrum empirical antimicrobial therapy is superior to limited-spectrum empirical antimicrobial therapy in intra-abdominal infections.

DESIGN

Prospective, randomized, double-blinded study.

SETTING

University-affiliated hospitals in Canada.

PATIENTS

Two hundred thirteen patients with intra-abdominal infections and planned operative or percutaneous drainage.

INTERVENTION

Limited-spectrum empirical antimicrobial therapy consisted of cefoxitin sodium, 2 g, intravenously, every 6 hours (n = 109). Comprehensive broad-spectrum empirical antimicrobial therapy consisted of a combination of imipenem and cilastatin sodium, 500 mg, intravenously, every 6 hours (n = 104).

MAIN OUTCOME MEASURES

Failure to cure the intra-abdominal infection (persistence of infection or death).

RESULTS

Of initial isolates, 98% were sensitive to imipenem plus cilastin sodium compared with 72% for cefoxitin. No difference was found in the failure rate between treatment groups. Among various reasons for failure (including technical), 12 of 80 patients in the limited-spectrum empirical antimicrobial therapy group had resistant organisms at a second intervention compared with 1 of 74 in the comprehensive broad-spectrum empirical antimicrobial therapy group (P < .003, chi 2). One death in the limited-spectrum empirical antimicrobial therapy group was due to autopsy-proved disseminated Pseudomonas aeruginosa (blood, peritoneum, lung, and pleural fluid) that was resistant to cefoxitin, and the other was associated with peritonitis due to cefoxitin-resistant Enterobacter cloacae. One death in the comprehensive broad-spectrum empirical antimicrobial therapy group was associated with peritonitis from Clostridium perfringens that was sensitive to imipenem plus cilastin sodium, and the other was associated with peritonitis from Pseudomonas aeruginosa that was resistant to imipenem plus cilastin sodium.

CONCLUSION

Treatment failure of intra-abdominal infection may be due, in part, to the presence of resistant pathogens at the site of infection. Therefore, routine culture of these sites seems worthwhile and empirical therapy should be as comprehensive as possible and should cover all potential pathogens.

Sensitivity of lungs of aging Fischer 344 rats to ozone: assessment by bronchoalveolar lavage

Biological effects indicators in bronchoalveolar lavage fluid were studied in Fischer 344 rats of different ages after exposure to 0.4-0.8 ppm ozone for periods of 2-6 h on a single day or on 4 consecutive days. The magnitude of alveolar protein transudation induced by ozone was not different between age groups, but the interindividual variability of protein changes was higher in senescent (24-mo-old) rats. By comparison to juvenile (2-mo-old) and adult (9-mo-old) rats, senescent animals had higher increases of interleukin-6 (up to 10-fold higher) and N-acetyl-beta-D-glucosaminidase (NAGA; 2-fold higher) in lung lavage after ozone. Ascorbic acid was lower in lungs of senescent rats (one-half of juvenile values), and acute ozone exposure brought a further decrease in lung ascorbate. Whereas alveolar protein transudation was attenuated after ozone exposure on 4 days, persistent elevation of NAGA in senescent rats suggested only partial adaptation. Injection of endotoxin did not modify the patterns of effects. Incorporation of 18O-ozone into macrophages and surfactant was not different between age groups, indicating that the magnified biological responses in senescent rats were not dominated by differences in internal dose of ozone. The results indicate that senescent rats respond differently than juvenile and adult rats to lung injury.

Laparoscopic transgastric suturing for bleeding peptic ulcers

BACKGROUND

Peptic ulcers are a frequent cause of upper G.I. bleeding. Since endoscopic methods may be unsuccessful, we have studied the feasibility of a new laparoscopic approach on a porcine model to control the bleeding of these ulcers with transgastric suturing.

METHODS

After approval of the Animal Ethics Committee, 20 pigs (20 kg) were anticoagulated with intravenous sodium heparin (400 U/kg), and anesthetized. A nasogastric tube was inserted and a 15 mmHg pneumoperitoneum was created. Two 10-mm trocars and one 5-mm trocar were inserted through the abdominal cavity for laparoscopic guidance of three 7-mm endoluminal trocars inside the stomach through the anterior wall. Two posterior gastric ulcers were mechanically made on each pig by a "lift and cut technique." Ulcers were observed for at least 1 min for evidence of continued bleeding. First, bleeding ulcers were treated with sclerosing agents (epinephrine and ethanolmine oleate 5%); following sclerotherapy, ulcers were sutured intraluminaly with 2-0 silk, with intracorporeal knots.

RESULTS

Ulcers created extended into the vascular submucosa and averaged 7 mm in diameter. Bleeding rate was variable, but significant (2 cm3/min) in 40%. It was technically possible to suture these ulcers in 80%. Bleeding was controlled in 95% of cases with sclerotherapy and intraluminal sutures. One perforation of the posterior gastric wall occurred and four endoluminal trocars had to be reinserted after dislodgement.

CONCLUSIONS

It is possible to technically control bleeding ulcers in most cases with a laparoscopic transgastric technique using sclerosing agent and intraluminal sutures. This approach is promising for future human application; also, the intragastric suturing skills developed may be useful for other surgical interventions.

Biliopancreatic Diversion with a New Type of Gastrectomy: Some Previous Conclusions Revisited

BACKGROUND: In 1990, we modified Scopinaro's billopancreatic diversion (BPD); instead of a distal gastrectomy and gastroileal anastomosis, a parietal gastrectomy was performed with nutrients diverted through a duodenal switch. Also, the length of the common channel (50 cm) was doubled to 100 cm, while the nutrient limb remained 250 cm. In 1991, we reported initial results after 16 months, weight loss was as expected following BPD, but patients reported fewer side-effects and the prevalence of excessive malabsorption was less. This cohort of patients had their duodenum stapled shut to construct the duodenal switch. This staple-line failed insidiously in some patients, allowing the duodenum to recanalize partially or completely. This resulted in an incomplete BPD. METHODS: Since 1992, the duodenal switch has been constructed with a complete transaction of the duodenum to prevent recanalization. We report here on the first 61 patients who underwent this definitive procedure. RESULTS: At 16 months, we observed a mean weight loss of 84% of initial excess weight, the number of daily stools at 2.9 +/- 1.6 and the prevalence of diarrhea at 10%. Twenty per cent of patients experienced mild anemia, hypocalcemia, or hypoalbuminemia, which required added supplements. CONCLUSIONS: BPD with parietal gastrectomy, duodenal switch and longer common channel improved weight loss and decreased gastrointestinal side-effects without an increased prevalence of excessive malabsorption. The parietal gastrectomy may contribute to weight loss by increasing satiety, and decreasing side-effects by regulating gastric emptying.

Biliopancreatic Diversion, with Distal Gastrectomy, 250 cm and 50 cm Limbs: Long-term Results

BACKGROUND: Since 1984, biliopancreatic diversion (BPD) has been our procedure of choice in the treatment of morbid obesity. Better understanding of long-term outcome following BPD is needed. METHODS: We report the results of our first consecutive 92 patients who underwent BPD more than 5 years ago. Of these 92, only 82 were available for a recent formal evaluation after a mean of 79 months. RESULTS: Weight loss, was maintained over the years at 62% of initial excess weight; the success rate for losing more than 50% of initial excess weight was 72%. The gastrointestinal side-effects decreased with time, but diarrhea was still present in 13%. The average number of daily stools was 3 +/- 1.0. Of the patients, 76% were free from any gastrointestinal side-effects, taking normal diet and having normal stools. Malabsorption, however, was still present. A third of patients had laboratory values slightly below normal levels for hemoglobin, albumin and calcium. These values were mostly without clinical manifestation and were well tolerated by the patients. Regarding associated diseases, 75% were cured or improved following BPD. In 14 patients, reoperation was required to improve diarrhea or serum albumin. In these patients, the common channel was lengthened from 50 to 100 cm. The revision was successful in 11 and did not cause significant weight gain. CONCLUSIONS: BPD, as proposed by Scopinaro, was an efficient surgical treatment of morbid obesity that allowed normal eating habits and despite malabsorption was well tolerated by the great majority of patients.

Short-term inhalation toxicity of methanol, gasoline, and methanol/gasoline in the rat

Four- to five-week-old male and female Sprague Dawley rats were exposed to vapors of methanol (2500 ppm), gasoline (3200 ppm), and methanol/gasoline (2500/3200 ppm, 570/3200 ppm) six hours per day, five days per week for four weeks. Control animals were exposed to filtered room air only. Depression in body weight gain and reduced food consumption were observed in male rats, and increased relative liver weight was detected in rats of both sexes exposed to gasoline or methanol/gasoline mixtures. Rats of both sexes exposed to methanol/gasoline mixtures had increased relative kidney weight and females exposed to gasoline and methanol/gasoline mixtures had increased kidney weight. Decreased serum glucose and cholesterol were detected in male rats exposed to gasoline and methanol/gasoline mixtures. Decreased hemoglobin was observed in females inhaling vapors of gasoline and methanol/gasoline at 570/3200 ppm. Urine from rats inhaling gasoline or methanol/gasoline mixtures had up to a fourfold increase in hippuric acid, a biomarker of exposure to the toluene constituent of gasoline, and up to a sixfold elevation in ascorbic acid, a noninvasive biomarker of hepatic response. Hepatic mixed-function oxidase (aniline hydroxylase, aminopyrine N-demethylase and ethoxyresorufin O-deethylase) activities and UDP-glucuronosyltransferase activity were elevated in rats exposed to gasoline and methanol/gasoline mixtures. Histopathological changes were confined to very mild changes in the nasal passages and in the uterus, where decreased incidence or absence of mucosal and myometrial eosinophilia was observed in females inhaling gasoline and methanol/gasoline at 570/3200 ppm. It was concluded that gasoline was largely responsible for the adverse effects, the most significant of which included depression in weight gain in the males, increased liver weight and hepatic microsomal enzyme activities in both sexes, and suppression of uterine eosinophilia. No apparent interactive effects between methanol and gasoline were observed.

Inhalation toxicity study of methanol, toluene, and methanol/toluene mixtures in rats: effects of 28-day exposure

The inhalation toxicity of methanol and toluene was investigated in rats. Young Sprague Dawley rats of both sexes were exposed to vapors of methanol (300 ppm, 3000 ppm), toluene (30 ppm, 300 ppm) or methanol/toluene (300/30 ppm, 300/300 ppm, 3000/30 ppm, and 3000/300 ppm) six hrs per day, five days/week for four weeks. Control animals inhaled air only. Increased serum alkaline phosphatase activity was observed in males exposed to high-dose toluene, and decreased creatinine was noted in the group exposed to high-dose methanol/toluene. The thyroid gland in females appeared to be a target organ for inhaled methanol, toluene, and methanol/toluene, although the changes were confined to a mild, and occasionally moderate, reduction in follicle size. Histopathological changes of the nasal passages, consisting of subepithelial nonsuppurative inflammation, occurred in higher incidences in rats exposed to methanol/toluene than in those exposed to the individual vapors. Inhalation of methanol, toluene, or methanol/toluene produced no changes in liver weights, hepatic mixed-function oxidases, or serum aspartate transaminase activities, and onlly minimal changes in liver histopathology. The only liver changes were decreased liver weight and increased cytoplasmic density of the periportal areas in females exposed to high-dose methanol/toluene. These data indicated that exposure to methanol, toluene, or a mixture of both produced mild biochemical effects and histological changes in the thyroid and nasal passage. No apparent interactive effects were observed.

The Angelchik antireflux prosthesis: long-term clinical and technical follow-up

OBJECTIVE

To evaluate the long-term clinical outcome and compare the rupture rate of the two generations of the silicone Angelchik antireflux prosthesis.

DESIGN

A cohort study. Follow-up ranged from 61 to 119 months.

SETTING

A university teaching hospital.

PATIENTS

Sixty-three patients: 33 patients received the first generation Angelchik device (group 1) and 30 patients received a second generation design (group 2). The two groups were comparable for sex ratio, mean age and duration of symptoms.

INTERVENTIONS

Implantation of the Angelchik prosthesis.

MAIN OUTCOME MEASURES

Comparison of the rupture rate and migration of the prosthesis as assessed by patient questionnaire, telephone interview and radiography of the abdomen.

RESULTS

The prosthesis remained in a good position in 53% of group 1 patients and 93% of group 2 patients. The prosthesis was removed in 40% of group 1 patients, most often for rupture, and in only 7% of patients in group 2, to relieve dysphagia (p < 0.01). Grading on a Visick scale demonstrated a good result in 37% of group 1 patients and 69% of group 2 patients. Long-term dysphagia was the most prevalent adverse effect, seen in 45% of patients whose prosthesis was in a good position, and symptomatic reflux recurred in 8%.

CONCLUSIONS

The second generation of the Angelchik prosthesis, resulted in a reduced rupture rate of the prosthesis. Nevertheless the high complication and the failure rates militate against continued implantation of the prosthesis.

The importance of dose scheduling with mitoxantrone, 5-fluorouracil and leucovorin in metastatic breast cancer

We have studied a mitoxantrone, 5-fluorouracil (5-FU) and leucovorin chemotherapy regimen in metastatic breast cancer. 8 patients received mitoxantrone 10 mg/m2 on day 1, leucovorin 200 mg/m2 and 5-FU 300 mg/m2 on days 1-5 by intravenous bolus every 28 days in a pilot study. Grades 3-4 granulocytopenia followed 55% of the courses, with 2 patients admitted for febrile neutropenia. Only a 29% objective response rate was seen in a subsequent phase II trial using reduced mitoxantrone doses. Comparison with other trials suggested that 5-day bolus 5-FU administration adversely affects the combination's therapeutic index.

Ondansetron compared with dexamethasone and metoclopramide as antiemetics in the chemotherapy of breast cancer with cyclophosphamide, methotrexate, and fluorouracil

BACKGROUND

Although ondansetron was found to be effective as an antiemetic in numerous clinical trials of highly emetogenic combination-chemotherapy regimens that included cisplatin, its role in milder emetogenic regimens has not been fully defined. To address its use with a widely used but less emetogenic regimen, we performed a double-blind, randomized clinical trial comparing ondansetron with dexamethasone and metoclopramide in patients with breast cancer receiving chemotherapy with cyclophosphamide, methotrexate, and fluorouracil.

METHODS

A total of 165 women with breast cancer from 14 Canadian centers who were about to receive this chemotherapy for the first time were randomly assigned to receive either ondansetron (n = 85) or dexamethasone plus metoclopramide (n = 80), a widely used, standard antiemetic regimen. The patients recorded the incidence of nausea, emesis, and other side effects in diaries, and these data were compared in the two groups.

RESULTS

The patients who received dexamethasone and metoclopramide had significantly less nausea during the first 24 hours after chemotherapy was begun. Otherwise, there were no statistically significant differences in efficacy between the regimens. The incidence of drowsiness and increased appetite was higher in the group given dexamethasone and metoclopramide.

CONCLUSIONS

For women with breast cancer who are being treated with cyclophosphamide, methotrexate, and fluorouracil, the efficacy of dexamethasone and metoclopramide in controlling nausea and vomiting equaled or exceeded that of ondansetron.

Biliopancreatic Diversion with a New Type of Gastrectomy

In an attempt to improve the results of biliopancreatic diversion in the treatment of morbid obesity, two aspects of the procedure performed at Laval Hospital were modified to reduce adverse physiological consequences. The distal gastrectomy was replaced by a parietal gastrectomy which preserves vagal continuity along with the lesser curvature, and leaves intact the antro-pyloroduodenal pump. The duodenum was stapled shut and nutrients were diverted through a duodeno-ileal anastomosis. The biliopancreatic diverting intestinal limb was anastomosed to the nutrient ileal limb 100 cm proximal to the ileocaecal valve instead of 50 cm proximal to it, thus doubling the length of the common ileal absorptive segment. Weight loss after either operation was greater than 70% of initial excess weight. Following the new operation, there was a lesser prevalence of side-effects, especially loose stools and malodorous gas, a lesser degree of hypocalcemia and no hypoalbuminemia. The duodenum recanalized at the staple line in 20% of the patients who had the new operation. When data from these patients were excluded, weight loss following the new operation was greater than that seen after the old one. The prevalence of side-effects and the degree of calcium and protein malabsorption remained significantly lower. Weight loss remained satisfactory with a common limb measuring 100 cm. The parietal gastrectomy was not restrictive as shown by the failure to lose further weight when the duodenal stapled diversion failed. Weight loss was thus mainly a function of biliopancreatic diversion, but increased weight loss in the new procedure despite a doubling of the common ileal limb suggests that parietal gastrectomy contributed to weight loss. Because duodenal recanalization can be corrected surgically and now prevented, the modified biliopancreatic bypass is preferred.

Use of an intensive task-oriented gait training program in a series of patients with acute cerebrovascular accidents

The aims of this case report are to describe the application of an early and intensive task-oriented physical therapy program for gait relearning following stroke and to report the patients' ability to comply with the program. Ten patients, 60 to 75 years of age (mean = 69.8, SD = 7.3), with a middle cerebral artery infarct (confirmed by computerized tomography) were assigned to this special physical therapy program. Patients were treated twice a day, 5 days a week, from the eighth day after stroke for 5 consecutive weeks. To promote gait relearning, a program of early standing (using a tilt table when necessary), combined with weight-shifting exercises and feedback via a limb-load monitor as well as locomotor activities including exercises on a Kinetron and treadmill walking, was adapted for each patient's level of motor recovery. Walking on the treadmill (with a safety harness) was initiated as early as the second week after stroke in 4 patients, and all patients had started Kinetron training by the second week. Except for 1 patient, who was withdrawn from the study because of an infection, all patients showed good treatment compliance (93.6%) with the planned 50 treatments and were able to withstand a mean treatment duration of 44.8 minutes (SD = 6.3, range = 37.5-58.5), twice a day, during the first week of the program (8th to 14th day after stroke). Results from this pilot project indicate that intensive and graded locomotor activities can be very well tolerated in the early period after stroke.

Subacute inhalation toxicity of benzaldehyde in the Sprague-Dawley rat

Benzaldehyde was administered by inhalation to female and male Sprague-Dawley rats for 14 consecutive days (low level: 500 ppm; medium level: 750 ppm; high level: 1000 ppm). Effects of this chemical were investigated during and at the end of the exposure period. Throughout the experiment, significant hypothermia and a reduction of motor activity were observed in all rats exposed to benzaldehyde and were accompanied in high-level rats by a severe impairment of the central nervous system, as evidenced by abnormal gait, tremors, and a positive Straub sign. Histopathologic examination of tissues from exposed rats showed a goblet cell metaplasia that was largely confined to the respiratory epithelium lining the nasal septum in male rats. No other abnormal microscopic changes were observed. A no effect level was not observed in these studies.

Biliopancreatic Diversion with Gastrectomy as Surgical Treatment of Morbid Obesity

The best procedure for the treatment of morbid obesity has not yet been defined. Biliopancreatic diversion is one of the techniques available, but its results have not been sufficiently documented and the addition of a subtotal gastrectomy to the diversion so as to avoid leaving a blind non-functioning stomach, is still questionable. The purpose of this paper is to report our experience with our first 149 consecutive patients who were treated by biliopancreatic diversion with subtotal gastrectomy for morbid obesity. Operative mortality was 3% and morbidity 12%. The weight loss was marked during the first 6 months and decreased during the following 12 months. The weight stabilized at 2 years and there was subsequently a small increase. In only two out of 48 cases was the weight loss less than 25% of the initial weight at 2 years. The undesirable side-effects were diarrhea in 6%, vomiting in 9% and dyspepsia in 4%. The intervention leads to a malabsorption of carotene, iron, albumin and calcium. Except for carotene the deficiencies were corrected by oral supplement. In two patients, with resistant deficiencies, the diversion was reversed. Eighty-eight percent of the patients are satisfied with this intervention. At 2 years, 70% have reached their weight loss objective without any major side-effects or nutritional deficiencies, but in 14% the outcome of the procedure must be considered unsatisfactory. Biliopancreatic diversion with subtotal gastrectomy is a major operation, but it gives encouraging results so far.

Adjuvant therapy of Dukes' A, B, and C adenocarcinoma of the colon with portal-vein fluorouracil hepatic infusion: preliminary results of National Surgical Adjuvant Breast and Bowel Project Protocol C-02

Between March 1984 and July 1988, 1,158 patients with Dukes' A, B, and C carcinoma of the colon were entered into National Surgical Adjuvant Breast and Bowel Project (NSABP) Protocol C-02. Patients were randomized to either no further treatment following curative resection or to postoperative fluorouracil (5-FU) and heparin administered via the portal vein. Therapy began on day of operation and consisted of constant infusion for 7 successive day. Average time on study was 41.8 months. A comparison between the two groups of patients indicated both an improvement in disease-free survival (74% v 64% at 4 years, overall P = .02) and a survival advantage (81% v 73% at 4 years, overall P = .07) in favor of the chemotherapy-treated group. When compared with the treated group, patients who received no further treatment had 1.26 times the risk of developing a treatment failure and 1.25 times the likelihood of dying after 4 years. Particularly significant was the failure to demonstrate an advantage from 5-FU in decreasing the incidence of hepatic metastases. The liver was the first site of treatment failure in 32.9% of 82 patients with documented recurrences in the control group and in 46.3% of 67 patients who received additional treatment. Therapy is administered via a regional route to affect the incidence of recurrence within the perfused anatomic boundary. Since, in this study, adjuvant portal-vein 5-FU infusion failed to reduce the incidence of hepatic metastases, it may be concluded that its use thus far is not justified. It may also be speculated that the disease-free survival and survival advantages (the latter of borderline significance) are a result of the systemic effects of 5-FU.

Biological conversion of benzaldehyde to benzylmercapturic acid in the Sprague-Dawley rat

The metabolism of benzaldehyde was investigated in Sprague-Dawley rats. After repeated oral administration of this compound (0.4-1.0 g/kg) for 13 consecutive days, urine was collected and analyzed for the presence of metabolites. The acidification of the pooled urine samples (pH:2.0) with 6 N H2SO4 was followed by ethyl acetate extraction, evaporation of the extract and methylation with diazomethane. Identification of the metabolite by comparison with a synthetic sample of benzylmercapturic acid (BENZM) was conducted by gas chromatography. Mass spectrometry examination of this metabolite revealed the following peaks characteristic of benzylmercapturic acid: m/z (%), 91(100), 176(27), 208(23), 43(20), 88(13), 117(10), 134(9), M+ 267(2). Monitoring of urines from both female and male rats showed a dose-related increase of benzylmercapturic acid which was found to be a reliable indicator of exposure to benzaldehyde.

Long-term results of hyperselective vagotomy for duodenal ulcer

Although considered by many as the operation of choice in the treatment of duodenal ulcer, hyperselective vagotomy without drainage is not unanimously accepted because little is known about its long-term efficiency in preventing ulcer recurrence. The long-term results of 203 patients with duodenal ulcer, treated by hyperselective vagotomy between 1974 and 1983 at the Hôpital Laval, are reported. Patients were followed at yearly intervals and questionnaires were used to determine whatever benefits they perceived. The procedure was found to be a safe one with an uncomplicated postoperative course. The overall recurrence rate was 12% over a mean follow-up of 64 months. Recurrences may occur 5 or more years after surgery. The operative technique is important in preventing recurrence. Dissection of the last 6 cm of esophagus lowered the recurrence rate at 5 years from 21% to 9%. Only four patients required reoperation. The majority of recurrences consisted of a single episode, the ulcer being easily controlled by short-course medical treatment. The authors found that 94% of patients were satisfied with the results of the operation.

Clinical experience with biliopancreatic bypass and gastrectomy or selective vagotomy for morbid obesity

In 1980 Scopinaro described biliopancreatic bypass for the treatment of obesity. This procedure was aimed at selective malabsorption. The authors used Scopinaro's procedure in 33 patients, but in 17 they modified it by doing selective vagotomy with closure of the duodenum in continuity instead of a subtotal gastrectomy. Eighteen months after the operation, 88% of the patients had what the authors considered was a good to excellent result, that is a loss of more than 25% of the patient's initial weight. Morbidity of many kinds was encountered but most was self-limiting or easily corrected by medical means. From their experience the authors conclude that biliopancreatic bypass as a procedure for the treatment of morbid obesity should continue to be performed and evaluated.

Short-term antibiotherapy for peritonitis: prospective, randomized trial comparing cefotaxime-metronidazole and clindamycin-tobramycin

The combination of cefotaxime and metronidazole has been suggested for the treatment of peritonitis. We compared their effectiveness with that of tobramycin and clindamycin. Since antibiotics have most of their beneficial effect within a few days a four day course was used and a randomized trial was undertaken. The effectiveness of the 4-day course was 86% and no difference was seen between the two groups of the study.

Cerebral abnormalities in hepatectomized rats with acute hepatic coma

When hepatectomized rats develop hepatic coma, they are found to have cerebral edema, together with a failure of the blood-brain barrier to contain materials usually limited to the circulation. The present studies were carried out to characterize the associated ultrastructural changes in the barrier. Rats were allowed to develop hepatic coma after a two-stage hepatectomy. Electrocortical and behavior monitoring during this period indicated deterioration similar to that seen in man with acute liver injury; the water contents of the brains of the animals in hepatic coma were increased. Electron microscopic examination of the brains from control rats and animals with hepatic coma were carried out after perfusion fixation. The examination of the brains from the comatose animals showed the appearance of greatly increased numbers of vesicles in the capillary endothelium and a marked watery swelling of adjacent astrocytes, which seemed to begin in foot processes and then to spread through the cell. Intravenous peroxidase was given to most rats in the late stages of coma, and the tracer was found to be included within the capillary endothelial vesicles. Occasional accumulations of peroxidase in the underlying capillary basement membrane were found. No interendothelial cell distruption was found. Low molecular weight microperoxidase was used as well as horseradish peroxidase; the results were the same with both compounds. The findings indicate as association between capillary endothelial vesicle formation and the cerebral edema found in animals with hepatic coma following hepatectomy.

Biological conversion of N-phenyl-2-naphthylamine to 2-naphthylamine in the Sprague-Dawley rat

The metabolism of a widely used plastic and rubber antioxidant, N-Phenyl-2-Naphthylamine, was investigated in Sprague-Dawley rats. After repeated oral administration of this compound, urine and feces were collected for several days and analyzed for the presence of metabolites. Identification techniques included a preliminary clean-up followed by thin-layer chromatography of amines and gas chromatography-mass spectrometry of their hexafluoroacyl derivatives (HFBA). The compounds identified in both urine and feces were characterized as N-Phenyl-2-Naphthylamine (PBNA) and 2-Naphthylamine (BNA). Data obtained on urinary excretion of BNA seem to indicate that repeated administration of PBNA enhances its own metabolism.

Acidic metabolites of pseudocumene in rabbit urine

In order to identify biological indicators of exposure to trimethylbenzenes, the metabolism of pseudocumene (1,2,4-trimethylbenzene) was investigated in rabbits. After oral administration of this compound, urine was collected for several days and analyzed for the presence of acidic metabolites. Isolation techniques included steam-distillation, direct extraction of urine by ethyl acetate, preparative thin-layer and column chromatography of the extract. The metabolites were identified by microanalysis, followed by TLC, gas chromatography-mass spectrometry, infrared and ultraviolet spectroscopy. Two major urinary metabolites were identified namely 2,4-dimethylbenzoic acid and 3,4-dimethylhippuric acid. The presence of these acidic metabolites in urine is a good indication of exposure to pseudocumene.

Studies on inhalation toxicity of 2-propanol

Biological effects of a single exposure to moderate or high concentrations of 2-propanol were investigated in Sprague-Dawley rats. Acute toxicity (LC50, t:8 hours) of this widely used solvent was determined and found to be 19000 ppm (17380-20760 ppm) for females and 22500 ppm (19200-26400 ppm) for males. Determination of blood levels of 2-propanol and its metabolite, acetone, was carried out during and after a single 4-hour exposure (Concentration range: 500 to 8000 ppm). The amount of acetone and 2-propanol was directly related to the various air concentrations of alcohol inhaled. Increase of exposure time to 8 hours enhanced considerably the amount of blood acetone which could be determined even 20 hours after exposure. These findings indicate a slow conversion of this alcohol to acetone which can be used as biochemical indicator to exposure. Histopathological examination of rats exposed to high levels of 2-propanol shows typical lesions of chemical pneumonitis and pulmonary edema accompanied by foamy vacuolization of liver cells and severe focal cytoplasmic degradation.

[Toxicological studies on dichloromethane, a solvent simulating carbon monoxide poisoning (author's transl)]

Acute oral and inhalation toxicity of dichloromethane was investigated in both male and female Sprague-Dawley rats. Oral LD50 was found to be 1.72 ml/kg for males and 1.06 ml/kg for females. LC50 was found to be 18 100 PPM (1 X 6 hours) for both male and female rats. Acute oral intoxication is characterized by severe vascular changes and depression of the central nervous system accompanied by gastro-intestinal hemorrhagy. A similar CNS depression is also found in acute intoxication by inhalation. The nature of the symptoms as well as the sequence of physiological (hypotension, hypothermia) and biochemical events observed (high COHb level, etc.) indicate that the combined action of dichloromethane and its metabolite, carbon monoxide, are responsible for the development of vascular and CNS disturbances and subsequently the sudden death of the animals.