Biomedical subjects

M Potvin

Publications and source records attributed to M Potvin.

At least 19 recordsLinked to original sources

PubMed2001

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.

Animals↗

PubMed1999

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.

Biliopancreatic Diversion↗

PubMed1999

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.

Animals↗

PubMed1998

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.

Adolescent↗

PubMed1998

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.

Animals↗

PubMed1997

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.

Anastomosis, Roux-en-Y↗

PubMed1997

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.

Acute Disease↗

PubMed1996

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.

Abdomen↗

PubMed1996

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.

Animals↗

PubMed1996

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.

Acetylglucosaminidase↗

PubMed1995

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.

Journal Article↗

PubMed1995

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.

Journal Article↗

PubMed1994

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.

Adenocarcinoma↗

PubMed1994

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.

Adult↗

PubMed1993

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.

Analysis of Variance↗

PubMed1993

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.

Journal Article↗

PubMed1992

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.

Aged↗

PubMed1991

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.

Administration, Inhalation↗