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1.
bioRxiv ; 2023 Aug 16.
Article in English | MEDLINE | ID: mdl-36789413

ABSTRACT

Objective: Inflammatory bowel diseases (IBD) are complex disorders. Iron accumulates in the inflamed tissue of IBD patients, yet neither a mechanism for the accumulation nor its implication on the course of inflammation are known. We hypothesized that the inflammation modifies iron homeostasis, affects tissue iron distribution and that this in turn perpetuates the inflammation. Design: This study analyzed human biopsies, animal models and cellular systems to decipher the role of iron homeostasis in IBD. Results: We found inflammation-mediated modifications of iron distribution, and iron-decoupled activation of the iron regulatory protein (IRP)1. To understand the role of IRP1 in the course of this inflammation-associated iron pattern, a novel cellular co-culture model was established, that replicated the iron-pattern observed in vivo, and supported involvement of nitric oxide in the activation of IRP1 and the typical iron pattern in inflammation. Importantly, deletion of IRP1 from an IBD mouse model completely abolished both, the misdistribution of iron and intestinal inflammation. Conclusion: These findings suggest that IRP1 plays a central role in the coordination of the inflammatory response in the intestinal mucosa and that it is a viable candidate for therapeutic intervention in IBD.

2.
J Thromb Haemost ; 17(1): 39-51, 2019 01.
Article in English | MEDLINE | ID: mdl-30506866

ABSTRACT

Essentials Phlebitis is one of the most frequent complications related to short peripheral catheters (SPC). A new SPC design, aimed for minimizing mechanical phlebitis, was tested in vivo in swine. MRI analysis revealed 40% less inflammation with the new SPC design compared to commercial SPC. The results confirm that our SPC biomechanical design approach can minimize phlebitis rates. SUMMARY: Background Short peripheral catheters (SPCs) are the most common intravenous device in today's medical practice. Short peripheral catheter thrombophlebitis (SPCT) occurs in up to 80% of hospitalized patients. Symptoms appear on average 3 days after catheter insertion and can lead to extended hospitalization and increased related costs. Here we introduce a novel SPC, named very short peripheral catheter (VSPC), that was designed to minimize biomechanical irritation and improve blood flow. Objective The goal was to test the performance of the novel catheter in vivo for reduction of thrombophlebitis. Methods Very short peripheral catheter prototypes were inserted into swine ear veins (n = 12). Verification of the catheter conformation in situ and blood perfusion was performed using Echo-Doppler. The SPCT development rate was measured using magnetic resonance imaging (MRI), 4 and 12 days after catheter insertion, and analyzed by means of edema and inflammation intensities. Blind histopathology analysis was performed on the veins postmortem. Clinically available SPC was used as a reference. Results Operation of the VSPC devices did not require any special skills over those used for the clinically available SPC. Echo-Doppler imaging confirmed that in contrast to the traditional SPC, the VSPC avoided contact with the vein wall and allowed better blood perfusion. The MRI analysis revealed 2-fold inflammation and edema rates (~80%) in the veins cannulated with the commercial SPC, whereas rates of only ~40% were seen with the novel VSPC. A similar trend was noticed in the histopathology analysis. Conclusions The results indicate that the novel catheter design significantly reduced SPCT rates and demonstrated proof of concept for our biomechanical approach.


Subject(s)
Catheterization, Peripheral/instrumentation , Ear/blood supply , Thrombophlebitis/prevention & control , Vascular Access Devices , Veins , Animals , Catheterization, Peripheral/adverse effects , Edema/etiology , Edema/prevention & control , Equipment Design , Female , Magnetic Resonance Angiography , Materials Testing , Models, Animal , Punctures , Sus scrofa , Thrombophlebitis/diagnostic imaging , Thrombophlebitis/etiology , Time Factors , Ultrasonography, Doppler , Veins/diagnostic imaging , Veins/pathology
3.
Vet Pathol ; 53(1): 170-81, 2016 Jan.
Article in English | MEDLINE | ID: mdl-25732176

ABSTRACT

Breast cancer is the most common cancer and the second-leading cause of cancer mortality in women in the United States. A recent 2-year National Toxicology Program carcinogenicity study showed an increased incidence of proliferative mammary lesions (hyperplasia, fibroadenoma, adenocarcinoma) in F344/NTac rats exposed to bromodichloroacetic acid (BDCA), a disinfection by-product in finished drinking water with widespread human exposure. We hypothesized that the increase in mammary tumors observed in BDCA-exposed F344/NTac rats may be due to underlying molecular changes relevant for human breast cancer. The objective of the study was to compare (1) gene and protein expression and (2) mutation spectra of relevant human breast cancer genes between normal untreated mammary gland and mammary tumors from control and BDCA-exposed animals to identify molecular changes relevant for human cancer. Histologically, adenocarcinomas from control and BDCA-exposed animals were morphologically very similar, were estrogen/progesterone receptor positive, and displayed a mixed luminal/basal phenotype. Gene expression analysis showed a positive trend in the number of genes associated with human breast cancer, with proportionally more genes represented in the BDCA-treated tumor group. Additionally, a 5-gene signature representing possible Tgfß pathway activation in BDCA-treated adenocarcinomas was observed, suggesting that this pathway may be involved in the increased incidence of mammary tumors in BDCA-exposed animals.


Subject(s)
Acetates/adverse effects , Adenocarcinoma/pathology , Mammary Neoplasms, Experimental/pathology , Transforming Growth Factor beta/metabolism , Adenocarcinoma/chemically induced , Animals , Female , Humans , Mammary Neoplasms, Experimental/chemically induced , Phenotype , Rats , Rats, Inbred F344
4.
Inhal Toxicol ; 25(3): 141-59, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23421486

ABSTRACT

Ozone (O3) is a pervasive air pollutant that produces pulmonary and cardiovascular dysfunction and possible neurological dysfunction. Young and old individuals are recognized as being susceptible to O3; however, remarkably little is known about susceptibility with senescence. This study explored the pulmonary, cardiovascular and neurological effects of O3 exposure in adult (4 m) and senescent (20 m) Brown Norway rats exposed to 0 or 0.8 ppm O3 for 6 h, 1 d/week, for 17 weeks. Ventilatory function was assessed 1 and 7 d after each exposure (Buxco). Heart rate, blood pressure (tail cuff) and motor activity were measured biweekly. Blood, aorta and bronchoalveolar lavage fluid (BALF) were analyzed 24 h after the last exposure for pulmonary inflammation, serum biomarkers and aorta mRNA markers of vascular disease. Measures of normal ventilatory function declined following each O3 exposure in both adult and senescent rats, however, senescent rats took weeks to exhibit a decline. Evidence for residual respiratory effects of O3 7 d after exposure in both age groups was observed. O3 had no effect on either heart rate or blood pressure, but decreased motor activity in both age groups. BALF indicated mild neutrophilic inflammation and protein leakage in adults. Age affected 17/58 serum analytes, O3 affected 6/58; 2/58 showed an age-O3 interaction. Leptin, adiponectin, lipocalin and insulin were increased in senescent rats. Overall, adult rats exhibited more immediate effects of episodic O3 than senescent rats. Residual effects were, however, obtained in both ages of rat, especially for ventilatory endpoints.


Subject(s)
Behavior, Animal/drug effects , Cardiovascular Diseases/chemically induced , Heart/drug effects , Lung/drug effects , Oxidants, Photochemical/toxicity , Ozone/toxicity , Adiponectin/metabolism , Age Factors , Aging , Animals , Biomarkers/metabolism , Cardiovascular Diseases/metabolism , Cardiovascular Diseases/physiopathology , Disease Susceptibility , Heart/physiopathology , Hemodynamics/drug effects , Insulin/metabolism , Leptin/metabolism , Lipocalins/metabolism , Lung/metabolism , Lung/physiopathology , Male , Motor Activity/drug effects , Rats , Rats, Inbred BN , Respiratory Function Tests
5.
J Toxicol Environ Health A ; 75(3): 183-200, 2012.
Article in English | MEDLINE | ID: mdl-22251266

ABSTRACT

In former mine workers and residents of Libby, Montana, exposure to amphibole-contaminated vermiculite has been associated with increased incidences of asbestosis and mesothelioma. In this study, long-term effects of Libby amphibole (LA) exposure were investigated relative to the well-characterized amosite asbestos in a rat model. Rat-respirable fractions of LA and amosite (aerodynamic diameter≤2.5 µm) were prepared by water elutriation. Male F344 rats were exposed to a single dose of either saline, amosite (0.65 mg/rat), or LA (0.65 or 6.5 mg/rat) by intratracheal (IT) instillation. One year after exposure, asbestos-exposed rats displayed chronic pulmonary inflammation and fibrosis. Two years postexposure, lung inflammation and fibrosis progressed in a time- and dose-dependent manner in LA-exposed rats, although the severity of inflammation and fibrosis was smaller in magnitude than in animals exposed to amosite. In contrast, gene expression of the fibrosis markers Col 1A2 and Col 3A1 was significantly greater in LA-exposed compared to amosite-exposed rats. There was no apparent evidence of preneoplastic changes in any of the asbestos-exposed groups. However, all asbestos-exposed rats demonstrated a significant increase in the expression of epidermal growth factor receptor (EGFR) 2 yr after instillation. In addition, only LA-exposed rats showed significant elevation in mesothelin (Msln) and Wilms' tumor gene (WT1) expression, suggesting possible induction of tumor pathways. These results demonstrate that a single IT exposure to LA is sufficient to induce significant fibrogenic, but not carcinogenic, effects up to 2 yr after exposure that differ both in quality and magnitude from those elicited by amosite administration at the same mass dose in F344 rats. Data showed that LA was on a mass basis less potent than amosite.


Subject(s)
Asbestos, Amosite/toxicity , Asbestos, Amphibole/toxicity , Animals , Biomarkers , Disease Models, Animal , Dose-Response Relationship, Drug , Environmental Exposure , ErbB Receptors/genetics , ErbB Receptors/metabolism , Fibrosis/pathology , GPI-Linked Proteins/genetics , GPI-Linked Proteins/metabolism , Gene Expression Regulation , Genes, Wilms Tumor/drug effects , Inflammation/pathology , Lung/drug effects , Lung/pathology , Male , Mesothelin , Rats , Rats, Inbred F344
6.
Br J Oral Maxillofac Surg ; 49(1): 21-5, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20034712

ABSTRACT

Female rats develop haemolytic anaemia and disseminated thrombosis and infarction in multiple organs, including bone, when exposed to 2-butoxyethanol (BE). There is growing evidence that vascular occlusion of the subchondral bone may play a part in some cases of osteoarthritis. The subchondral bone is the main weight bearer as well as the source of the blood supply to the mandibular articular cartilage. Vascular occlusion is thought to be linked to sclerosis of the subchondral bone associated with disintegration of the articular cartilage. The aim of this study was to find out whether this model of haemolysis and disseminated thrombosis supports the vascular hypothesis of osteoarthritis. Six female rats were given BE orally for 4 consecutive days and the two control rats were given tap water alone. The rats were killed 26 days after the final dose. The mandibular condyles showed histological and radiological features consistent with osteoarthritis in three of the four experimental rats and in neither of the control rats. These results may support the need to explore the vascular mechanism of osteoarthritis further.


Subject(s)
Anemia, Hemolytic/complications , Bone and Bones/blood supply , Disseminated Intravascular Coagulation/complications , Ethers/adverse effects , Ethylene Glycols/adverse effects , Infarction/complications , Osteoarthritis/etiology , Solvents/adverse effects , Temporomandibular Joint Disorders/etiology , Animals , Cartilage, Articular/blood supply , Cartilage, Articular/diagnostic imaging , Chondrocytes/pathology , Disease Models, Animal , Female , Growth Plate/pathology , Mandibular Condyle/blood supply , Mandibular Condyle/diagnostic imaging , Osteophyte/pathology , Osteosclerosis/etiology , Radiography , Random Allocation , Rats , Rats, Inbred F344 , Whole Body Imaging
7.
Toxicol Pathol ; 38(3): 372-81, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20233943

ABSTRACT

B6C3F1 mice chronically exposed to 3,3',4,4'-tetrachloroazobenzene (TCAB), a contaminant of dichloroaniline-derived herbicides, developed a number of neoplastic and nonneoplastic lesions, including carcinoma of the urinary tract. Groups of fifty male and fifty female B6C3F1 mice were exposed by gavage to TCAB at dose levels of 0, 3, 10, and 30 mg/kg five days a week for two years. Control animals received corn oil:acetone (99:1) vehicle. Decreased survival of male mice in the mid-dose group and of male and female mice in the high-dose groups was related mainly to the occurrence of urethral transitional cell (urothelial) carcinoma and resulting urinary obstruction. Increased urethral transitional cell carcinomas were seen in all treated male groups in a dose-related manner as well as in the females treated with 30 mg/kg TCAB. Administration of TCAB was also associated with increased transitional cell hyperplasia of the urethra. Most nonneoplastic lesions of the urogenital tract were considered secondary to local invasion and urinary obstruction by the urethral transitional cell carcinomas. The mechanism of tumor induction is uncertain, but the high frequency of tumors in the proximal urethra of male mice suggests that the neoplasms result from the exposure of a susceptible population of urothelial cells to a carcinogenic metabolite of TCAB.


Subject(s)
Azo Compounds/toxicity , Carcinogens/toxicity , Carcinoma, Transitional Cell/chemically induced , Chlorobenzenes/toxicity , Urethral Neoplasms/chemically induced , Animals , Carcinoma, Transitional Cell/pathology , Female , Herbicides/toxicity , Hyperplasia/chemically induced , Hyperplasia/pathology , Kidney Diseases/chemically induced , Kidney Diseases/pathology , Male , Mice , Ureteral Neoplasms/chemically induced , Ureteral Neoplasms/pathology , Urethral Diseases/chemically induced , Urethral Diseases/pathology , Urethral Neoplasms/pathology , Urinary Bladder Neoplasms/chemically induced , Urinary Bladder Neoplasms/pathology
8.
J Biomater Sci Polym Ed ; 20(7-8): 1081-90, 2009.
Article in English | MEDLINE | ID: mdl-19454170

ABSTRACT

We evaluated the biocompatibility of an injectable gelling polymeric device for the controlled release of gentamicin sulfate in the treatment of invasive bacterial infections in bone of male Wister rats. The biodegradable delivery carrier, poly(sebacic-co-ricinoleic-ester-anhydride), designated as p(SA:RA), was injected, with and without gentamicin, into the tibial canal. Rats were killed 3 weeks later. The tibiae were processed histologically, leaving the injectable polymer in situ. The local tissue reaction to the polymer with or without antibiotic consisted mainly of mild reactive fibroplasia/fibrosis and mild to moderate increased reactive bone formation. At this stage, no evidence for any active inflammatory response to the polymer was seen. Thus, the injection of p(SA:RA) was well tolerated and did not induce any signs of a progressive inflammatory reaction.


Subject(s)
Drug Carriers/adverse effects , Materials Testing/methods , Osteomyelitis/drug therapy , Polymers/adverse effects , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Delayed-Action Preparations , Drug Carriers/administration & dosage , Drug Carriers/chemistry , Inflammation/chemically induced , Injections , Male , Osteomyelitis/microbiology , Osteomyelitis/pathology , Polymers/administration & dosage , Polymers/chemistry , Rats , Rats, Wistar
9.
Food Chem Toxicol ; 47(4): 729-33, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19166900

ABSTRACT

Trivalent chromium (Cr(III)) has been proposed to be an essential element, which may increase sensitivity to insulin and thus participate in carbohydrate and lipid metabolism. Humans ingest Cr(III) both as a natural dietary constituent and in dietary supplements taken for weight loss and antidiabetic effects. Chromium picolinate (CP), a widely used supplement, contains Cr(III) chelated with three molecules of picolinic acid and was formulated in an attempt to improve the absorption of Cr(III). In order to examine the potential for CP to induce chronic toxicity and carcinogenicity, the NTP conducted studies of the monohydrate form (CPM) in groups of 50 male and female F344/N rats and B6C3F1 mice exposed in feed to concentrations of 0, 2000, 10,000 or 50,000 ppm for 2 years; exposure concentrations were selected following review of the data from NTP 3-month toxicity studies. Exposure to CPM did not induce biologically significant changes in survival, body weight, feed consumption, or non-neoplastic lesions in rats or mice. In male rats, a statistically significant increase in the incidence of preputial gland adenoma at 10,000 ppm was considered an equivocal finding. CPM was not carcinogenic to female rats or to male or female mice.


Subject(s)
Neoplasms, Experimental/chemically induced , Picolinic Acids/toxicity , Toxicity Tests, Chronic , Animals , Carcinogenicity Tests , Female , Male , Mice , Rats , Rats, Inbred F344
10.
J Biomed Mater Res A ; 88(2): 427-36, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18306316

ABSTRACT

Nonbiodegradable polymer coating based on N-(2-carboxyethyl)pyrrole (PPA) and butyl ester of PPA (BuOPy) were successfully electrodeposited on a stainless steel stent surface using cyclic voltammetry. Chemical composition of the coating was examined by X-ray photoelectron spectroscopy. Polymer stability was examined by immersing the coated stent into 1:1 solution of fetal calf serum:seline solution up to 1 year and implantation subcutaneously in mouse for 1 week. Morphology changes were then recorded by scanning electron microscopy. Paclitaxel loading was carried out by immersion into drug solution and its release was detected by HPLC. The results show that thin (single micrometers), uniform coating with various morphology and hydrophobicity can be created by electrochemical deposition. The polymer did not show significant histopathological or morphological changes in vitro and in vivo. The surface properties allow loading appropriate amounts of paclitaxel and release it slowly up to a month.


Subject(s)
Antineoplastic Agents, Phytogenic/chemistry , Antineoplastic Agents, Phytogenic/metabolism , Coated Materials, Biocompatible , Paclitaxel/chemistry , Paclitaxel/metabolism , Stainless Steel/chemistry , Stents , Animals , Antineoplastic Agents, Phytogenic/administration & dosage , Coated Materials, Biocompatible/chemistry , Coated Materials, Biocompatible/metabolism , Drug Delivery Systems , Electrochemistry , Esters/chemistry , Female , Materials Testing , Mice , Molecular Structure , Paclitaxel/administration & dosage , Polymers/chemistry , Polymers/metabolism , Pyrroles/chemistry , Surface Properties
11.
Arch Toxicol ; 82(1): 45-53, 2008 Jan.
Article in English | MEDLINE | ID: mdl-17619857

ABSTRACT

4-Methylimidazole (4MI) is used in the manufacture of pharmaceuticals, photographic chemicals, dyes and pigments, cleaning and agricultural chemicals, and rubber. It has been identified as a by-product of fermentation in foods and has been detected in mainstream and side stream tobacco smoke. 4MI was studied because of its high potential for human exposure. Groups of 50 male and 50 female F344/N rats were fed diets containing 0-, 625-, 1,250-, or 2,500 ppm 4MI (males) or 0-, 1,250-, 2,500-, or 5,000 ppm 4MI (females) for 106 weeks. Based on the food consumption the calculated average daily doses were approximately 30, 55, or 115 mg 4MI/kg body weight to males and 60, 120, or 250 mg 4MI/kg to females. Survival of all exposed groups of males and females was similar to that of the control groups. The mean body weights of males in the 1,250- and 2,500 ppm groups and females in the 2,500- and 5,000 ppm groups were less than those of the control groups throughout the study. Feed consumption by 5,000 ppm females was less than that by the controls. Clonic seizures, excitability, hyperactivity, and impaired gait were observed primarily in 2,500- and 5,000 ppm females. The incidence of mononuclear cell leukemia in the 5,000 ppm females was significantly greater than that in the controls. The incidences of hepatic histiocytosis, chronic inflammation, and focal fatty change were significantly increased in all exposed groups of male and female rats. The incidences of hepatocellular eosinophilic and mixed cell foci were significantly increased in 2,500 ppm males and 5,000 ppm females. Groups of 50 male and 50 female B6C3F1 mice were fed diets containing 0-, 312-, 625-, or 1,250 ppm 4MI for 106 weeks. Based on the food consumption the calculated average daily doses were approximately 40, 80, or 170 mg 4MI/kg body weight to males and females. Survival of all exposed groups of males and females was similar to that of the control groups. Mean body weights of males and females in the 1,250 ppm groups and that in the 312- and 625 ppm females were less than those of the control groups. Feed consumption by exposed groups of male and female mice was similar to that by the controls. The incidences of alveolar/bronchiolar adenoma in all exposed groups of females, alveolar/bronchiolar carcinoma in 1,250 ppm males, and alveolar/bronchiolar adenoma or carcinoma (combined) in 1,250 ppm males and 625- and 1,250 ppm females were significantly greater than those in the control groups. The incidence of alveolar epithelial hyperplasia was significantly increased in the 1,250 ppm females. 4MI is carcinogenic inducing alveolar/bronchiolar adenoma and carcinoma in male and female mice. 4MI may also induce mononuclear cell leukemia in female rats.


Subject(s)
Carcinogens , Imidazoles/toxicity , Animals , Carcinogenicity Tests , Chemical and Drug Induced Liver Injury/pathology , Eating/drug effects , Female , Histiocytosis/chemically induced , Histiocytosis/epidemiology , Leukemia/chemically induced , Leukemia/epidemiology , Liver/pathology , Male , Mice , Nervous System Diseases/chemically induced , Rats , Rats, Inbred F344 , Seizures/chemically induced , Species Specificity , Survival Analysis
12.
Arch Toxicol ; 82(6): 399-412, 2008 Jun.
Article in English | MEDLINE | ID: mdl-17924096

ABSTRACT

2-Methylimidazole (2MI) has been identified as a by-product of fermentation and is detected in foods and mainstream and side-stream tobacco smoke. It is used in the manufacture of pharmaceuticals, photographic chemicals, dyes and pigments, agricultural chemicals, and rubber. Carcinogenicity studies of 2MI were conducted because of its high potential for human exposure and a lack of carcinogenicity data. Groups of male and female Fischer 344/N rats were fed diets containing 0, 300, 1,000, or 3,000 ppm (males) or 0, 1,000, 2,500, or 5,000 ppm (females) 2MI for 106 weeks and groups of male and female B6C3F1 mice were fed 0, 625, 1,250, or 2,500 ppm 2MI for 105 weeks. Animals in each group were sacrificed at 8 days, 14 weeks, and 6 months for determinations of serum thyroid hormone and liver enzyme levels and histopathological examinations and at 2 years for evaluations of neoplastic lesions. In rats, 2MI administration reduced serum thyroxine and triiodothyronine and increased thyroid stimulating hormone levels. 2MI administration also increased total hepatic UDP-glucuronosyltransferase levels. At 2 years, the incidences of thyroid follicular cell hyperplasia, adenoma or carcinoma (combined), as well as follicular mineralization were increased. The incidences of hepatocellular adenoma or carcinoma (combined) in the two highest dose groups of males and females were also increased. The incidences of mixed cell focus in males and females were also significantly increased. In mice, the incidences of thyroid follicular cell hypertrophy and hyperplasia were significantly increased in the high dose males and females. The incidence of thyroid follicular cell adenoma in the 2,500 ppm males was significantly greater than that in the control group. The incidences of hepatocellular adenoma or carcinoma (combined) were significantly increased in all exposed groups of males and in the 2,500 ppm females. Significant increases in incidences were also observed in spleen hematopoietic cell proliferation in both sexes and bone marrow hyperplasia, chronic active inflammation of the epididymis, sperm granuloma, and germinal epithelial atrophy of the testis in males. Under these experimental conditions, carcinogenic activity of 2MI was demonstrated in male and female rats and mice.


Subject(s)
Adenocarcinoma/chemically induced , Adenoma/chemically induced , Carcinogens/toxicity , Imidazoles/toxicity , Liver Neoplasms/chemically induced , Thyroid Neoplasms/chemically induced , Adenocarcinoma/blood , Adenocarcinoma/pathology , Adenoma/blood , Adenoma/pathology , Administration, Oral , Animals , Carcinogenicity Tests , Dose-Response Relationship, Drug , Female , Glucuronosyltransferase/metabolism , Liver/drug effects , Liver/enzymology , Liver/pathology , Liver Neoplasms/blood , Liver Neoplasms/pathology , Male , Mice , Mice, Inbred C57BL , Organ Size/drug effects , Rats , Rats, Inbred F344 , Thyroid Hormones/blood , Thyroid Neoplasms/blood , Thyroid Neoplasms/pathology , Thyrotropin/blood
13.
Toxicol Pathol ; 35(5): 657-64, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17676524

ABSTRACT

Ma Huang (equivalent to 0, 12.5, 25, or 50 mg/kg ephedrine) or ephedrine (0, 6.25, 12.5, 25 mg/kg) were administered as one bolus oral dose to male F344 rats with and without caffeine. The herbal medicine Ma Huang (ephedra) in combination with caffeine caused rapid clinical signs of toxicity including salivation, hyperactivity, ataxia, and eventually lethargy, and failure to respond to stimuli. When this syndrome of clinical signs emerged, animals were moribund sacrificed, and a histological analysis for heart lesions performed. Cardiotoxicity included hemorrhage, necrosis, and degeneration in the ventricles or interventricular septum within 2-4 hours after treatment with Ma Huang (ephedra)/caffeine or ephedrine (the principal active component in Ma Huang)/caffeine. There was a steep dose response curve for cardiotoxicity with minimal toxicity seen at levels of Ma Huang (equivalent to 12.5 mg/kg ephedrine) with caffeine. However, cardiotoxic lesions occurred in 28% of animals with Ma Huang dosages equivalent to 25 mg/kg ephedrine with 15 or 30 mg/kg caffeine, and in 90% of animals at Ma Huang exposures equivalent to 50 mg/kg ephedrine with 15 or 30 mg/kg caffeine. Cardiotoxic lesions occurred in 47% of animals in the 25 mg/kg ephedrine groups with caffeine at 7.25, 15, or 30 mg/kg. There was no statistical difference in the occurrence of cardiotoxic lesions when 15 or 30 mg/kg caffeine was combined with Ma Huang equivalent to 25 or 50 mg/kg ephedrine; likewise there was no statistical difference in the occurrence of cardiotoxic lesions when 7.25, 15, or 30 mg/kg caffeine was combined with 25 mg/kg ephedrine. These results show that the cardiotoxic effects of the herbal medicine, Ma Huang, are similar to that of ephedrine, the principal active ingredient in the herbal medicine. The combination of Ma Huang or ephedrine with caffeine enhanced the cardiotoxicity over that with the herbal medicine or the active ingredient alone.


Subject(s)
Caffeine/toxicity , Ephedra sinica/toxicity , Ephedrine/toxicity , Heart/drug effects , Animals , Male , Models, Animal , Myocardium/pathology , Rats , Rats, Inbred F344
14.
J Neural Transm (Vienna) ; 114(5): 595-605, 2007.
Article in English | MEDLINE | ID: mdl-17177075

ABSTRACT

The neuroprotective effects of intravenous rasagiline were investigated in a rat model of stroke. Middle cerebral artery (MCA) occlusion was performed in male rats and the short- (neurological severity score [NSS], infarct size), intermediate- (cognition) and long-term (necrotic area) effects were assessed. A bolus (3 mg/kg) of rasagiline followed by a 3-h infusion (3 mg/kg/h), initiated immediately after MCA occlusion, reduced infarct size by 48.6% and NSS by 32.7% relative to saline treatment. Cognitive function, tested in a water maze 2-3 weeks after occlusion, also significantly improved compared with saline-treated controls. Necrotic brain area was 35-50% smaller with rasagiline than with saline following a single bolus dose. The single bolus rasagiline dose was as effective as a rasagiline bolus followed by rasagiline infusion in short-term outcomes. The neuroprotective effect of rasagiline was fully reproducible when administered at 2 h following occlusion but not after 4 h.


Subject(s)
Brain Infarction/drug therapy , Brain Ischemia/drug therapy , Indans/pharmacology , Nerve Degeneration/drug therapy , Neuroprotective Agents/pharmacology , Animals , Brain Infarction/pathology , Brain Infarction/physiopathology , Brain Ischemia/pathology , Brain Ischemia/physiopathology , Cognition Disorders/drug therapy , Cognition Disorders/etiology , Cognition Disorders/physiopathology , Disease Models, Animal , Dose-Response Relationship, Drug , Drug Administration Schedule , Indans/therapeutic use , Infarction, Middle Cerebral Artery/drug therapy , Infarction, Middle Cerebral Artery/pathology , Infarction, Middle Cerebral Artery/physiopathology , Male , Maze Learning/drug effects , Nerve Degeneration/etiology , Nerve Degeneration/prevention & control , Neuroprotective Agents/therapeutic use , Rats , Rats, Wistar , Recovery of Function/drug effects , Recovery of Function/physiology , Time Factors , Treatment Outcome
15.
Toxicol Pathol ; 34(4): 348-56, 2006.
Article in English | MEDLINE | ID: mdl-16844662

ABSTRACT

Gene transcript changes after exposure to the heart toxin, bis(2-chloroethoxy)methane (CEM), were analyzed to elucidate mechanisms in cardiotoxicity and recovery. CEM was administered to 5-week-old male F344/N rats at 0, 200, 400, or 600 mg/kg by dermal exposure, 5 days per week, for a total of 12 doses by study day 16. Heart toxicity occurred after 2 days of dosing in all 3 regions of the heart (atrium, ventricle, interventricular septum) and was characterized by myofiber vacuolation, necrosis, mononuclear-cell infiltration, and atrial thrombosis. Ultrastructural analysis revealed that the primary site of damage was the mitochondrion. By day 5, even though dosing was continued, the toxic lesions in the heart began to resolve, and by study day 16, the heart appeared histologically normal. RNA was extracted from whole hearts after 2 or 5 days of CEM dosing. After a screen for transcript change by microarray analysis, dose-response trends for selected transcripts were analyzed by qRT-PCR. The selected transcripts code for proteins involved in energy production, control of calcium levels, and maintenance of heart function. The down-regulation of ATP subunit transcripts (Atp5j, ATP5k), which reside in the mitochondrial membranes, indicated a decrease in energy supply at day 2 and day 5. This was accompanied by down-regulation of transcripts involved in high-energy consumption processes such as membrane transport and ion channel transcripts (e.g., abc1a, kcnj12). The up-regulation of transcripts encoding for temperature regulation and calcium binding proteins (ucp1 and calb3) only at the 2 low exposure levels, suggest that these adaptive processes cannot occur in association with severe cardiotoxicity as seen in hearts at the high exposure level. Transcript expression changes occurred within 2 days of CEM exposure, and were dose-and time-dependent. The heart transcript changes suggest that CEM cardiotoxicity activates protective processes associated energy conservation and maintenance of heart function.


Subject(s)
Ethyl Ethers/toxicity , Gene Expression Regulation/drug effects , Myocardium/metabolism , Myocardium/pathology , Transcription, Genetic/drug effects , Animals , Dose-Response Relationship, Drug , Drug Administration Schedule , Ethyl Ethers/chemistry , Male , Mitochondria, Heart/drug effects , Mitochondria, Heart/pathology , Mitochondria, Heart/ultrastructure , Molecular Structure , Molecular Weight , Myocardium/ultrastructure , Oligonucleotide Array Sequence Analysis , Rats , Rats, Inbred F344 , Reverse Transcriptase Polymerase Chain Reaction , Time Factors
16.
Toxicol Pathol ; 34(4): 385-92, 2006.
Article in English | MEDLINE | ID: mdl-16844666

ABSTRACT

Adenoviral vectors have been shown to efficiently deliver exogenous genes to salivary glands and have therefore been investigated as tools for the treatment of human disease. The purpose of this study was to evaluate the response of F344 rats to intraductal infusion of the right submandibular salivary gland with an adenoviral vector encoding the gene for human growth hormone (AdCMVhGH). Co-administration of hydroxychloroquine (HCQ) was used to redirect the secretion of human growth hormone (hGH) from saliva into serum. This paper documents the findings of the pathology evaluation of this National Toxicology Program study. The right submandibular salivary gland (infusion site) was the primary target organ, with microscopic lesions characteristic of a mild to moderate insult observed at 3 days post infusion in vector exposed animals. These lesions were characterized by variable degrees of acute glandular inflammation, degeneration and necrosis, with more severe lesions in the higher dose groups. Rats at 28 days post infusion had milder inflammation, degeneration and necrosis compared to day 3 rats, with variable degrees of regeneration. In conclusion, the effects on the salivary glands are reversible as indicated by the milder inflammation and degeneration in the day 28 rats concomitant with mild to moderate regeneration. Therefore, the vector appears relatively innocuous with limited tissue toxicity. [The supplemental data referenced in this paper is not printed in this issue of Toxicologic Pathology. It is available as a downloadable file in the online edition of Toxicologic Pathology, 34(4). In order to access the full article online, you must have either an individual subscription or a member subscription accessed through www.toxpath.org.].


Subject(s)
Gene Transfer Techniques , Genetic Vectors , Human Growth Hormone/genetics , Submandibular Gland/metabolism , Transduction, Genetic , Adenoviridae/genetics , Animals , Antirheumatic Agents/administration & dosage , Antirheumatic Agents/pharmacology , Female , Fibrosis/chemically induced , Fibrosis/pathology , Humans , Hydroxychloroquine/administration & dosage , Hydroxychloroquine/pharmacology , Incidence , Inflammation/chemically induced , Inflammation/pathology , Injections, Intraperitoneal , Male , Necrosis/chemically induced , Necrosis/pathology , Random Allocation , Rats , Rats, Inbred F344 , Submandibular Gland/drug effects , Submandibular Gland Diseases/chemically induced , Submandibular Gland Diseases/epidemiology , Submandibular Gland Diseases/pathology , Time Factors
17.
Oral Dis ; 12(2): 137-44, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16476034

ABSTRACT

OBJECTIVE: We examined the toxicity and biodistribution associated with a single administration of a first-generation, serotype 5, adenoviral vector encoding human growth hormone (hGH; AdCMVhGH) to a single rat submandibular gland in the presence of hydroxychloroquine (HCQ). Previously, we showed that hGH is primarily secreted into saliva (approximately ninefold serum level) when expressed as a transgene in salivary glands (e.g. Baum et al, 1999), but administration of HCQ substantially increases the hGH levels secreted into the bloodstream (Hoque et al, 2001). A potential application of this observation is for patients with adult hGH deficiency. METHODS: Six groups of male and female adult rats (n = 12 each) were studied, with zero to 1.5 x 10(11) particles of AdCMVhGH, +/-HCQ, administered retroductally. Multiple clinical and pathological parameters, as well as vector tissue distribution, were assessed. RESULTS: All animals survived until the scheduled day of sacrifice, and essentially no untoward events were observed clinically or at gross necropsy. We observed no vector-related effects on clinical hematology evaluations and a single, transient significant change on clinical chemistry evaluations (increased serum globulin levels). Three days after AdCMVhGH administration, the vector distributed to all tissues analyzed with the exception of gonads and heart. By day 29, most organs, other than the targeted and contralateral submandibular glands, were negative for the presence of vector. On day 3, none of the animals tested positive for the presence of replication competent adenovirus in either their blood or saliva. CONCLUSION: Salivary gland delivery of AdCMVhGH +/-HCQ appears associated with limited toxicity in rats.


Subject(s)
Adenoviridae/genetics , Antirheumatic Agents/pharmacology , Genetic Vectors/genetics , Human Growth Hormone/genetics , Hydroxychloroquine/pharmacology , Submandibular Gland/metabolism , Alanine Transaminase/blood , Alkaline Phosphatase/blood , Amylases/blood , Animals , Female , Human Growth Hormone/toxicity , Humans , L-Lactate Dehydrogenase/blood , Male , Plasmids/genetics , Rats , Rats, Inbred F344 , Recombinant Proteins , Serum Globulins/analysis , Submandibular Gland/drug effects , Tissue Distribution , Virus Replication
18.
Vet Pathol ; 42(3): 306-14, 2005 May.
Article in English | MEDLINE | ID: mdl-15872376

ABSTRACT

The transgenic adenocarcinoma mouse prostate (TRAMP) model, designed for researching human prostatic cancer, was genetically engineered to harbor a transgene composed of the simian virus 40 Large-T/small-t antigen promoted by the rat probasin gene. In addition to prostatic neoplasms, the TRAMP mouse develops tumors in the seminal vesicles. This study was conducted to evaluate the pathology and histogenesis of TRAMP seminal vesicle neoplasms. Tissues of accessory sex organs harvested from 72 TRAMP mice of various ages (11-40 weeks of age) were fixed in neutral buffered formalin and stained with hematoxylin and eosin, desmin, 5-bromo-2'-deoxyuridine (BrdU, treated animals only), and SV40 Large-T antigen (SV40-Tag). In the seminal vesicles, we found neoplastic stromal cells that emerged multicentrically just beneath the epithelium, densely packed between the epithelium and the smooth muscle layer. These stromal cells frequently exhibited mitotic figures and showed BrdU incorporation and SV40-Tag protein expression in the nuclei and immunopositivity for desmin. The proliferative mesenchymal cells were lined by cuboidal to columnar epithelium. Some of the larger papillary, polypoid lesions exhibited a phyllodes pattern resembling that seen in mixed epithelial-stromal tumors of the breast, prostate, and seminal vesicles of humans. Although the epithelium was negative for SV40-Tag and showed only occasional incorporation of BrdU, it clearly participated in the biphasic proliferation, forming papillary, cystic, and tubuloglandular structures. No conclusive evidence of malignancy (invasion or metastasis) was identified. Our recommended diagnosis of this lesion in the seminal vesicles is epithelial-stromal tumor.


Subject(s)
Carcinoma/pathology , Genital Neoplasms, Male/pathology , Seminal Vesicles/pathology , Animals , Antigens, Polyomavirus Transforming/metabolism , Bromodeoxyuridine , Carcinoma/diagnosis , Desmin/immunology , Genital Neoplasms, Male/diagnosis , Immunohistochemistry , Male , Mice , Mice, Transgenic , Seminal Vesicles/cytology , Stromal Cells/pathology
20.
Vet Pathol ; 42(2): 132-9, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15753466

ABSTRACT

Immunohistochemistry, the standard method for diagnosing amyloid A (AA) amyloidosis, is limited in animals because it requires a large array of animal-specific anti-AA antibodies, not commercially available. The Shtrasburg method (SH method) is a highly specific and sensitive technique, helping in the diagnosis and determination of AA amyloidosis in humans. The aim of this study is to determine whether the SH method is applicable in the diagnosis of AA amyloidosis in a variety of animals. Tissue samples were obtained from animals suffering from spontaneous or experimentally induced AA amyloidosis (mice, hamsters, guinea pigs, cheetahs, cats, cows, ducks, a dog, a goose, a chicken, and a turaco). Detection of the amyloid and quantitative evaluation were performed using Congo red staining, and specific AA typing was performed by the potassium permanganate technique. The studied tissues were subjected to the SH method, which confirmed the AA nature of the amyloid deposit, by displaying in polyacrylamide gel electrophoresis protein bands consistent with the molecular weight of the species-specific AA, in all the animals examined, except mice, hamsters, and guinea pigs. N-terminal analysis of these bands corroborated their AA origin. We conclude that the SH method may be used as an ancillary simple tool for the diagnosis of AA amyloidosis in a large number of domestic and wild animals. Moreover, our findings further increase the feasibility of applying this method in humans.


Subject(s)
Amyloidosis/veterinary , Serum Amyloid A Protein/analysis , Acinonyx , Amyloidosis/diagnosis , Animals , Cats , Cattle , Chickens , Cricetinae , Dogs , Ducks , Electrophoresis, Polyacrylamide Gel/veterinary , Female , Geese , Guinea Pigs , Male , Mice , Species Specificity
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