Home About us Contact
|
Home About us Contact | ||
|
|
||
Histopathologic Changes (histopathologic + change)
Selected AbstractsTime-related Histopathologic Changes in Fresh Frozen Carotid Xenografts in a Pig-to-Goat Implantation ModelARTIFICIAL ORGANS, Issue 10 2009Ji M. Chang Abstract We performed an animal experiment with an emphasis on time-related histopathologic changes to evaluate the clinical feasibility of immunologically nontreated xenogenic vascular grafts. Bilateral porcine carotid arteries were harvested, and then, after short-term freezing at ,70°C, interposed into goats' carotid arteries. An antiplatelet agent was administered orally for 3 months postoperatively. The goats were randomly assigned to five periods of observation (1 week, and 1, 3, 6, and 12 months after implantation); two animals were observed at each of these times. Doppler ultrasonography was performed periodically during the observation period. At predetermined times, grafts were explanted and examined using hematoxylin and eosin, and Masson's trichrome stains. Immunohistochemical evaluations were conducted with T-lymphocyte indicator and von Willebrand factor. Two goats died prematurely, one from respiratory problems related to anesthesia and the other from pneumonia. A total of 16 grafts from the remaining eight animals were evaluated. Grafts were all patent except one at 3 months after transplantation. Histologically, xenogenic arterial grafts showed early endothelial cell loss at 1 week. This was followed by a progressive spread of recipient endothelial cells from the anastomotic site, and re-endothelialization was complete at 1 month. The degree of neointimal and medial thickening increased until 3 months, and then decreased. At 12 months, no additional growth of the intimal or medial layers was observed. Adventitial inflammation became severe at 3 months, but was reduced at 6,12 months. The proportions of CD3-positive T-lymphocytes among inflammatory cell infiltrations were very low. Fresh frozen xenogenic arterial grafts showed acceptable patency throughout the 12-month period and showed no evidence of being unduly influenced by rejection reactions. [source] Requirement of toll-like receptor 7 for pristane-induced production of autoantibodies and development of murine lupus nephritis,ARTHRITIS & RHEUMATISM, Issue 4 2008Emina Savarese Objective The detection of high titers of antibodies against small nuclear ribonucleoproteins (snRNP) is a diagnostic finding in patients in whom systemic lupus erythematosus (SLE) is suspected. Endogenous RNA molecules within snRNP trigger Toll-like receptor 7 (TLR-7) activation in B cells and dendritic cells, leading to anti-snRNP antibody production, which is associated with the development of immune complex nephritis in SLE. The purpose of this study was to investigate the role of TLR-7 in anti-snRNP antibody production and renal disease in SLE induced by an exogenous factor in the absence of genetic predisposition, using the pristane-induced murine lupus model. Methods Serum autoantibodies, IgG isotypes, and cytokine levels in pristane-treated wild-type and TLR-7,deficient mice were analyzed by enzyme-linked immunosorbent assay. Histopathologic changes in mouse kidneys were determined by light immunofluorescence microscopy. Cell subsets in splenocytes and peritoneal lavage cells from the mice were examined by flow cytometry. Results We found that anti-snRNP antibody production induced by pristane treatment was entirely dependent on the expression of TLR-7, whereas anti,double-stranded DNA antibody production was not affected by a lack of TLR-7. Impaired anti-snRNP antibody production in TLR-7,deficient mice was paralleled by lower levels of glomerular IgG and complement deposits, as well as less severe glomerulonephritis. Conclusion TLR-7 is specifically required for the production of RNA-reactive autoantibodies and the development of glomerulonephritis in pristane-induced murine lupus, a model of environmentally triggered SLE in the absence of genetic susceptibility to autoimmunity. Specific interference with TLR-7 activation by endogenous TLR-7 ligands may therefore be a promising novel strategy for the treatment of SLE. [source] Histopathologic changes at "synovio,entheseal complexes" suggesting a novel mechanism for synovitis in osteoarthritis and spondylarthritisARTHRITIS & RHEUMATISM, Issue 11 2007Michael Benjamin Objective To determine the extent to which different entheses form part of a "synovio,entheseal complex" (SEC) and whether such SECs are commonly associated with the presence of inflammatory cells and evidence of enthesis microdamage. Methods Specimens from 49 cadaveric entheses were processed for histologic study, and all soft tissue components of the entheses or enthesis organs were examined. To exclude articular cartilage degeneration as a triggering factor for synovitis, the selected entheses included 17 that were not immediately adjacent to such cartilage. Results An SEC was present at 82% of entheses. These included 47% of the attachments not adjacent to articular cartilage, where the synovium was that of bursae or tendon sheaths. One or more of a wide variety of degenerative changes were noted on the soft tissue side of every enthesis; the most common changes were cell clustering and/or fissuring (in 76% of entheses). Synovial villus formation or inflammatory cell infiltration was seen in 85% of entheses, and in 73% of attachments there were also inflammatory cells in the enthesis organ itself. The changes included synovial invasion (pannus formation) of the enthesis. Conclusion Entheses are frequently juxtaposed to synovium, thus forming SECs. They are also often associated with both degenerative and inflammatory changes, and the latter may involve the immediately adjacent synovium. These findings suggest a novel mechanism by which synovitis could develop in both degenerative joint disease and spondylarthritis. [source] Pendred's syndrome with goiter and enlarged vestibular aqueducts diagnosed by PDS gene mutation,HEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 7 2002Hajime Ishinaga MD Abstract Background Pendred's syndrome (PS) is an autosomal recessive disorder characterized by goiter and congenital sensorineural hearing loss. Recent advances in molecular biology revealed the gene responsible for PS (PDS) and provided an important aid for the diagnosis of this condition. Methods A case of PS with huge goiter and congenital hearing impairment was diagnosed by mutational analysis of the PDS gene. Results Physical examination and computer tomography CT revealed a diffuse swelling of the thyroid gland. Thyroid function tests were normal, and the perchlorate discharge test was negative. Audiologic examination confirmed sensorineural hearing loss, and temporal bone CT revealed bilateral enlarged vestibular aqueducts. The mutational analysis revealed that the patient was homozygous for His 723 Arg (2168A,G) in exon 19, a missense mutation. Conclusions The results of thyroid function tests in PS patients are usually normal, and the positive perchlorate discharge test has been used for the diagnosis. However, this is a nonspecific test and is not sensitive enough for PS. In our case, despite a negative perchlorate test, the patient was diagnosed by mutational analysis and received total thyroidectomy to relieve respiratory distress caused by thyroid enlargement. This is the first report of a mutation detected in the thyroid tissue and clearly shows that the mutation caused histopathologic change in that gland. © 2002 Wiley Periodicals, Inc. [source] Nail Biopsy: Assessment of Indications and OutcomeDERMATOLOGIC SURGERY, Issue 2 2005Chander Grover MD, MNAMS Background For years, nail biopsy has been shunned as a difficult and scarring procedure, which is seldom required in day-to-day practice. Only a few studies with a limited number of patients have been carried out to assess its utility in dermatology. Methods We studied 270 patients with nail disorders (both infectious and noninfectious). In 205 cases, the clinical diagnosis could be confirmed with the help of routine diagnostic aids, in the form of potassium hydroxide preparation, fungal culture, and biopsy of associated skin lesions. In the remaining 65 cases, various types of nail biopsies were carried out after ruling out contraindications to nail surgery. Results Overall, the histopathologic changes were found to be diagnostic in 63% of cases. Findings were more characteristic in infectious disorders of the nail unit. The diagnostic yield varied with the type of biopsy procedure. Side effects in the form of scarring and nail dystrophy were seen in 29.2% of the patients. Discussion Nail biopsy is useful, especially in cases with isolated nail involvement, an absence of skin lesions, and disorders such as twenty-nail dystrophy. It should be advocated in cases in which the routine diagnostic procedures fail to yield results. Proper selection of cases, choice of biopsy technique, and attention to the surgical procedure help in minimizing the side effects associated with the procedure. Conclusion Nail biopsy was found to be a simple, safe, and useful procedure, especially in cases in which the clinical diagnosis is otherwise obscure. CHANDER GROVER, MD, DNB, MNAMS, SONI NANDA, MD, B. S. N. REDDY, MD, MNAMS, AND KRISHNAMOORTHY UMA CHATURVEDI, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPPORTERS. [source] Hepatocellular carcinoma occurring in nonfibrotic liver: Epidemiologic and histopathologic analysis of 80 French casesHEPATOLOGY, Issue 2 2000Marie-Pierre Bralet M.D., Ph.D. Hepatocellular carcinoma (HCC) occurring in nonfibrotic liver represents a rare, ill-defined subgroup of HCC without cirrhosis in which mechanisms of hepatocarcinogenesis remain unclear. The aim of our study was to assess epidemiological factors and detailed histopathologic changes in the nontumoral liver of patients developing such tumors. Of 330 HCCs resected in our institution between 1985 and 1998, we retrospectively analyzed 80 cases (53 men, 27 women; mean age, 51 ± 16 years) in which the nontumoral liver showed no (n = 28) or minimal (n = 52) portal fibrosis without any septal fibrosis. In the group with no portal fibrosis there was no male predominance, and patients were significantly younger (44 ± 19 years vs. 54 ± 14 years) than those with minimal portal fibrosis. Sixty-seven tumors were typical HCCs, 8 were of fibrolamellar type, and 5 were hepatocholangiocarcinomas. Mean tumor size was 10 ± 5 cm. Risk factors for HCC development were found in 30 patients: hepatitis B (n = 17) or C (n = 2) virus infections, alcohol consumption (n = 11), and hemochromatosis (n = 1). In the nontumoral liver, periportal and lobular necrosis, mild portal inflammation, steatosis, and iron overload were present in 15%, 57%, 52%, and 54% of cases, respectively. Liver cell changes were noted in 6%. This study emphasizes the need for strict criteria to classify HCC without cirrhosis. HCC in nonfibrotic liver is a distinct subgroup in which nontumoral liver shows nonspecific minimal changes without regeneration or premalignant lesion. Etiologic factors are often unidentified, although presence of HBV infection in 21% suggests a direct oncogenic role of this virus. [source] Protective effect of non-mitogenic human acidic fibroblast growth factor on hepatocyte injuryHEPATOLOGY RESEARCH, Issue 10 2007Hua Xu Aim:, To study whether non-mitogenic human acidic fibroblast growth factor (nm-haFGF) has protective effects on H2O2 -induced hepatocyte injury in vitro and CCl4 -induced hepatocyte injury in vivo. Methods:, (i) HL-7702 hepatocytes were incubated with different concentrations of nm-haFGF for 12 h, and then the activity of lactate dehydrogenase (LDH) in culture medium was detected, and genomic DNA electrophoresis analysis was observed after being exposed to H2O2 (8 mmol/L) for 4 h. Proximately, apoptotic rates and protein expressions of Bcl-2 and Bax of HL-7702 cell were detected after being exposed to H2O2 (0.2 mmol/L) for 20 h. (ii) Being injected intraperitoneally with nm-haFGF, mice were treated with CCl4 intraperitoneally to induce hepatic injury. Twenty-four hours later, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured and histopathologic changes were evaluated. Results:, (i) In vitro tests: LDH activities and apoptotic rates decreased, the protein expression of Bcl-2 increased and Baxdecreased in nm-haFGF-treated groups at the concentrations of 100 150 and 200 ng/mL, compared with that in the model control group, which was treated with H2O2 alone. The genomic DNA remained nearly intact at the concentrations of 150 and 200 ng/mL. (ii) In vivo tests: serum ALT and AST in nm-haFGF-treated groups (10 ,g/kg and 20 ,g/kg) were much lower as compared to the model control group, which was treated with CCl4 alone. Histological examination showed that nm-haFGF markedly ameliorated hepatocytes vacuolation, cloudy swelling and inflammatory cells infiltration induced by CCl4. Conclusion:, nm-haFGF had protective effects against H2O2 -induced hepatocyte injury in vitro and CCl4 -induced acute liver injury in vivo. [source] Isoflurane enhances spontaneous Ca2+ oscillations in developing rat hippocampal neurons in vitroACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2009Q. XIANG Background: During the nervous system development, spontaneous synchronized Ca2+ oscillations are thought to possess integrative properties because their amplitude and frequency can influence the patterning of neuronal connection, neuronal differentiation, axon outgrowth, and long-distance wiring. Accumulating studies have confirmed that some drugs such as volatile anesthetic isoflurane produced histopathologic changes in the central nervous system in juvenile animal models. Because the hippocampus plays an important role in learning and memory, the present work was designed to characterize the Ca2+ oscillations regulated by volatile anesthetic isoflurane in primary cultures of developing hippocampal neurons (5-day-cultured). Methods: Primary cultures of rat hippocampal neurons (5-day-cultured) were loaded with the Ca2+ indicator Fluo-4AM (4 ,M) and were studied with a confocal laser microscope. Results: Approximately 22% of 5-day-cultured hippocampal neurons exhibited typical Ca2+ oscillations. These oscillations were dose-dependently enhanced by isoflurane (EC50 0.5 MAC, minimum alveolar concentration) and this effect could be reverted by bicuculline (50 ,M), a specific ,-aminobutyric acid (GABAA) receptor antagonist. Conclusion: Unlike its depressant effect on the Ca2+ oscillations in adult neurons in previous researches, isoflurane dose-dependently enhanced calcium oscillations in developing hippocampal neurons by activating GABAA receptors, a major excitatory receptor in synergy with N -methyl- d -aspartate receptors at the early stages of development. It may be involved in the mechanism of an isoflurane-induced neurotoxic effect in the developing rodent brain. [source] Troglitazone prevents fatty changes of the liver in obese diabetic ratsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 10 2000Dong Mei Jia Abstract Background and Aims: Troglitazone is a newly developed antidiabetic drug and is indicated to be useful for the treatment of patients with type II diabetes mellitus. Recently, however, it became clear that troglitazone could cause liver dysfunction in some patients. In addition, a relationship between the activation of the peroxisome proliferator-activated receptor gamma receptor by troglitazone and colon tumorigenesis has been suggested. The present study was undertaken to examine the effects of long-term administration of troglitazone on the liver and intestine in genetically obese and diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) and control Long-Evans Tokushima Otsuka (LETO) rats. Methods: A troglitazone-rich diet (200 mg/100 g normal chow) or a standard rat chow, free of troglitazone (control), was given to OLETF and LETO rats from 12 or 28 weeks of age until 72 weeks of age. Serum levels of glucose, insulin, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were determined at several time points. In addition, histology of the liver and intestine and serum levels of cholesterol and triglycerides were examined at 72 weeks of age. Results: Troglitazone prevented age-related increases in fasting glucose and insulin concentrations in OLETF rats, but had no significant influences on serum levels of AST and ALT in both strains of rats. The liver weights in the control OLETF rats were significantly heavier than in the LETO rats. Troglitazone significantly reduced serum cholesterol and triglyceride levels and the liver weight. However, it had no influence on the large intestine weight and the number of colonic polyps in both OLETF and LETO rats. Sections of the liver from the untreated OLETF rats showed mild fatty changes in the central zone of the hepatic lobule, whereas those from the troglitazone-treated OLETF rats appeared normal with no fat deposition in the hepatocytes. Troglitazone in LETO rats also caused no significant histopathologic changes of the liver tissue. Conclusion: Our present study demonstrated that long-term administration of troglitazone prevents the progress of the metabolic derangement and fatty changes of the liver in genetically determined obese diabetes. [source] Critical ischemic time for the rat ovary: Experimental study evaluating early histopathologic changesJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 2 2009Ayhan Coskun Abstract The aim of the present study was to determine a critical ischemic time for ovary in an experimental study in rats. An experimental model using slip-knot tying of all ovarian arteries and veins in cycling female rats was developed. Rat ovaries were tied using the technique through an explorative laparotomy. Complete ischemia times of 1, 2 and 3 h were used for the study. At the end of the ischemic times, the ovaries were harvested following 1 h of reperfusion. Histology indicated a gradually increased congestion correlating with the respective increased ischemic times. According to the present findings 2 h complete ischemia yields a significant injury. The model used in the present study may be used for complete ischemia,reperfusion injury of the rat ovary. [source] CTLA-4Ig blocks the development and progression of citrullinated fibrinogen,induced arthritis in DR4-transgenic miceARTHRITIS & RHEUMATISM, Issue 10 2010David Yue Objective To assess the role of T cells in the mouse model of citrullinated human fibrinogen,induced rheumatoid arthritis (RA) using CTLA-4Ig, an agent that blocks T cell costimulation, which is required for T cell activation. Methods Humanized HLA,DR,1*0401,transgenic (DR4-Tg) mice were immunized with Cit,human fibrinogen to induce arthritis. Prior to, and at the onset or peak of, arthritis, the DR4-Tg mice were treated with CTLA-4Ig or control human IgG1 or were left untreated. Arthritis development and progression were monitored by measuring ankle swelling with calipers and by assessing histopathologic changes. The immune responses to the citrullinated antigens and the corresponding unmodified antigens, as well as the arthritogenicity of lymphocytes from these mice, were examined. The latter was performed using lymphocyte transfers from CTLA-4Ig,treated or control mice via intraperitoneal injection into naive DR4-Tg mice. Recipient mice also received an intraarticular injection of Cit,human fibrinogen, unmodified human fibrinogen, or vehicle. Results CTLA-4Ig,treated, but not human IgG1-treated, arthritic mice had significantly reduced ankle swelling and pathologic joint damage. Treatment with CTLA-4Ig, but not human IgG1, suppressed Cit,human fibrinogen,induced T cell activation, including citrulline-specific T cell activation, when given prior to disease onset. Transfer of splenic lymphocytes from untreated or human IgG1,treated arthritic mice caused arthritis in recipients, and this occurred when Cit,human fibrinogen, but not unmodified fibrinogen, was deposited into the joint. Splenocytes from CTLA-4Ig,treated mice were unable to transfer arthritis. Conclusion Activated citrulline-specific T cells play a direct role in the development and progression of arthritis in this model of Cit,human fibrinogen,induced RA. [source] The histopathologic associates of neurometabolite abnormalities in fatal neuropsychiatric systemic lupus erythematosusARTHRITIS & RHEUMATISM, Issue 7 2010William M. Brooks Objective To determine the histopathologic basis of altered brain neurometabolites in neuropsychiatric systemic lupus erythematosus (NPSLE). Methods Brain neurometabolite concentrations in a 20-voxel area of the brain were determined premortem by magnetic resonance spectroscopy (MRS) in 7 individuals with NPSLE. Absolute concentrations of neurometabolite for N -acetylaspartate (NAA), choline, creatine, and lactate were measured. After the death of the patients, histopathologic changes were determined at autopsy of the brain and were matched voxel-by-voxel with the neurometabolites. Results The mean ± SD absolute concentrations of NAA (9.15 ± 1.78 mM in patients versus 12.2 ± 0.8 mM in controls; P < 0.01) and creatine (6.43 ± 0.16 mM in patients versus 6.90 ± 0.60 mM in controls; P < 0.003) were significantly reduced and the concentration of choline (2.51 ± 0.42 mM in patients versus 1.92 ± 0.32 mM in controls; P < 0.04) was significantly elevated in NPSLE patients as compared with controls. Widespread heterogeneous changes in the histologic features of the brain were present, including microinfarcts, microhemorrhages, bland angiopathy, thrombotic angiopathy with platelet and fibrin thrombi, neuronal necrosis in various states of resolution, reduced numbers of axons and neurons, vacuole and space formation among the fibers, reduced numbers of oligodendrocytes, reactive microglia and astrocytes, lipid-laden macrophages, and cyst formation. Neurometabolite abnormalities were closely associated with underlying histopathologic changes in the brain: 1) elevated choline levels were independently associated with gliosis, vasculopathy, and edema (r = 0.75, P < 0.004 in the multivariate model); 2) reduced creatine levels with reduced neuronal,axonal density and gliosis (r = 0.72, P < 0.002 in the multivariate model); 3) reduced NAA levels with reduced neuronal,axonal density (r = 0.66, P < 0.001 in the multivariate model); and 4) the presence of lactate with necrosis, microhemorrhages, and edema (r = 0.996, P < 0.0001 in the multivariate model). Conclusion Altered neurometabolites in NPSLE patients, as determined by MRS, are a grave prognostic sign, indicating serious underlying histologic brain injury. [source] Amelioration of brain pathology and behavioral dysfunction in mice with lupus following treatment with a tolerogenic peptideARTHRITIS & RHEUMATISM, Issue 12 2009Smadar Lapter Objective Central nervous system (CNS) involvement in systemic lupus erythematosus (SLE) is manifested by neurologic deficits and psychiatric disorders. The aim of this study was to examine SLE-associated CNS pathology in lupus-prone (NZB × NZW)F1 (NZB/NZW) mice, and to evaluate the ameliorating effects of treatment with a tolerogenic peptide, hCDR1 (human first complementarity-determining region), on these manifestations. Methods Histopathologic analyses of brains from lupus-prone NZB/NZW mice treated with vehicle, hCDR1, or a control scrambled peptide were performed. The messenger RNA expression of SLE-associated cytokines and apoptosis-related molecules from the hippocampi was determined. Anxiety-like behavior was assessed by open-field tests and dark/light transfer tests, and memory deficit was assessed using a novel object recognition test. Results Infiltration was evident in the hippocampi of the lupus-afflicted mice, and the presence of CD3+ T cells as well as IgG and complement C3 complex deposition was observed. Furthermore, elevated levels of gliosis and loss of neuronal nuclei immunoreactivity were also observed in the hippocampi of the mice with lupus. Treatment with hCDR1 ameliorated the histopathologic changes. Treatment with hCDR1 down-regulated the high expression of interleukin-1, (IL-1,), IL-6, IL-10, interferon-,, transforming growth factor ,, and the proapoptotic molecule caspase 8 in the hippocampi of the mice with lupus, and up-regulated expression of the antiapoptotic bcl -xL gene. Diseased mice exhibited increased anxiety-like behavior and memory deficit. Treatment with hCDR1 improved these parameters, as assessed by behavior tests. Conclusion Treatment with hCDR1 ameliorated CNS pathology and improved the tested cognitive and mood-related behavior of the mice with lupus. Thus, hCDR1 is a novel candidate for the treatment of CNS lupus. [source] Time-related Histopathologic Changes in Fresh Frozen Carotid Xenografts in a Pig-to-Goat Implantation ModelARTIFICIAL ORGANS, Issue 10 2009Ji M. Chang Abstract We performed an animal experiment with an emphasis on time-related histopathologic changes to evaluate the clinical feasibility of immunologically nontreated xenogenic vascular grafts. Bilateral porcine carotid arteries were harvested, and then, after short-term freezing at ,70°C, interposed into goats' carotid arteries. An antiplatelet agent was administered orally for 3 months postoperatively. The goats were randomly assigned to five periods of observation (1 week, and 1, 3, 6, and 12 months after implantation); two animals were observed at each of these times. Doppler ultrasonography was performed periodically during the observation period. At predetermined times, grafts were explanted and examined using hematoxylin and eosin, and Masson's trichrome stains. Immunohistochemical evaluations were conducted with T-lymphocyte indicator and von Willebrand factor. Two goats died prematurely, one from respiratory problems related to anesthesia and the other from pneumonia. A total of 16 grafts from the remaining eight animals were evaluated. Grafts were all patent except one at 3 months after transplantation. Histologically, xenogenic arterial grafts showed early endothelial cell loss at 1 week. This was followed by a progressive spread of recipient endothelial cells from the anastomotic site, and re-endothelialization was complete at 1 month. The degree of neointimal and medial thickening increased until 3 months, and then decreased. At 12 months, no additional growth of the intimal or medial layers was observed. Adventitial inflammation became severe at 3 months, but was reduced at 6,12 months. The proportions of CD3-positive T-lymphocytes among inflammatory cell infiltrations were very low. Fresh frozen xenogenic arterial grafts showed acceptable patency throughout the 12-month period and showed no evidence of being unduly influenced by rejection reactions. [source] Toxicity Profile of Lisdexamfetamine Dimesylate in Three Independent Rat Toxicology StudiesBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 4 2007Suma Krishnan The toxicity profile of orally administered LDX has been evaluated in rats. In an acute study, LDX doses of 60 mg/kg and higher caused increased motor activity. At 1000 mg/kg, one rat died and another was euthanized. In a 7-day repeat-dose study, all rats dosed with LDX (14 per dose group for each sex) showed increased activity; 10 male rats and 11 female rats at 300 mg/kg/day and 3 female rats at 100 mg/kg/day were euthanized because of self-mutilation and 1 male rat at 300 mg/kg/day was found dead. In a 28-day study, only rats at 80 mg/kg showed signs of self-mutilation and thin body condition. In both the 7- and 28-day studies, LDX caused significant changes in some blood chemistry parameters (e.g. blood urea nitrogen, alanine aminotransferase, aspartate aminotransferase) and organ weights (e.g. particularly heart, liver, brain, and spleen). Overall, no apparent treatment-related histopathologic changes were observed. Toxicokinetic assessments indicated that as the dose of LDX was increased, rats were exposed to increasing levels of LDX and d -amphetamine. The extent of exposure to LDX and d -amphetamine increased after repeated-dose in the 28-day study. The findings of the repeat-dose studies indicate that the toxicity profile in rats administered LDX orally is comparable to that for d -amphetamine; however, the apparent lethal dose of LDX in rats is more than five times higher than the LD50 of orally administered d -amphetamine, supporting a putative protective effect of conjugating amphetamine with lysine. [source] Lithium isotopes: differential effects on renal function and histologyBIPOLAR DISORDERS, Issue 4 2001Peter M Stoll Objectives: Reduction in renal concentrating ability has been reported in patients undergoing chronic lithium treatment. Prior work has demonstrated differences in physiological effects of the stable lithium isotopes, 6Li and 7Li. Here, we measured the degree of polyuria, polydipsia and kidney histological changes induced in rats by equimolar amounts of 6LiCl, 7LiCl and the commercially available mixture of both isotopes. Methods: Rats were given 1.0 mEq/kg of either 6LiCl, 7LiCl or ,nLiCl' (isotope mixture, 93% 7LiCl) by subcutaneous injection twice daily for up to 49 days. Twenty-four-hour urine volume and water intake were measured daily. Kidneys from rats treated for 7 days with 1.5 mEq/kg 6LiCl, 7LiCl and vehicle were examined under light microscopy and histopathologic changes graded on a 4-point scale of severity. Results: All rats showed loss in renal concentrating ability manifested by increasing urine volume and water intake. Peak effects occurred after 9,13 days treatment, then declined to stable levels at two to three times pre-treatment level. Mean peak effect was significantly greater for 6LiCl than for 7LiCl. Chronic effects of 6LiCl (weeks 3,7 of treatment) on polyuria and polydipsia were persistently higher than that of 7LiCl. nLiCl effect was intermediate. Kidneys from rats treated for 7 days with 6LiCl showed more frequently severe lesions in renal tubules than did 7LiCl-treated rats. Conclusions: Our current data and prior studies suggest that elimination or reduction of 6Li from pharmaceutical preparations may merit further evaluation as a possibly less potentially nephrotoxic form of lithium treatment. [source] | ||||||||||