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Journal Article 2006; 27(1-2): 128-132 PubMed PMID: 16648788 Citation  Keywords:  Acetylcholine:metabolism, Animals, Blood Glucose:metabolism, Hippocampus:metabolism, Hypoglycemia:chemically induced, Hypoglycemic Agents, Insulin, Male, Microdialysis, Neostriatum:drug effects, Rats, Rats, Wistar,.   

OBJECTIVE: It has been well acknowledged that hypoglycemia induces cognitive impairment. However, the behavior of hippocampal cholinergic system, which is thought to play a key role in cognition, during hypoglycemia remains to be elucidated.

MATERIALS AND METHODS: In this study we conducted a microdialysis using 9 weeks old virgin male Wistar/ST rats to determine the changes of extracelluar acethylcholine and glucose levels in the hippocampus during insulin-induced severe hypoglycemia, and compared the results with those obtained from a microdialysis in the striatum.

RESULTS: The extracelluar concentrations of acethylcholine both in the hippocampus and striatum did not change during hypoglycemia.

CONCLUSION: The results of the present study may suggest that changes of hippocampal cholinergic release may not be involved in the mechanism of cognitive impairment during hypoglycemia....

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Comparative Study 2005; 26(6): 843-847 PubMed PMID: 16380695 Citation  Keywords:  Animals, Anticonvulsants:toxicity, Female, Fertility:drug effects, Fetal Resorption:chemically induced, Fructose:analogs & derivatives, Male, Organ Size, Ovary:anatomy & histology, Pregnancy, Rats, Rats, Sprague-Dawley,.   

PURPOSE: The objectives of this study is to investigate the toxic effects of Topamax (100 mg/kg/body weight) on the reproductive system after administration to female Sprague-Dawley rats weighing 250-300 g for two time periods 4 and 12 weeks.

METHODS: Twenty adult female rats were divided into two groups and exposed to Topiramate diet at a concentration of 100 mg/kg/body weight for two periods of time. First group containing 10 rats received treatment for 4 weeks and a second group of 10 rats received the same dose of treatment for a period of 12 weeks and compared with twenty non-exposed female rats received vehicle treatment. Female rats were allowed mating with males after 10 days prior to the last administration dose. Animals were autopsied under light anesthesia after mating and several parameters were determined including: number of pregnant rats, body and reproductive organ weight, number of implantation sites, viable fetuses, and resorption sites. Assessment of pregnancies in females was measured and the significance of these results was calculated using student's 't' and Chi-square tests.

RESULTS: The effect of Topamax exposure on fertility was assessed in terms of pregnant rats number, implantation sites, viable fetuses, and resorption sites. Exposure to Topamax for 4 weeks did not have much effect on fertility. Significant decrease in the relative ovarian weights and embryo weights in rats exposed to Topamax were observed. Exposure to Topamax for a 12 weeks resulted in a reduction in the percentage of pregnancies and in the number of implantation sites, when compared with controls in both treatment periods. Rats receiving 12 weeks treatment showed an increase in ovarian weights and a decrease in viable fetuses number. These results indicate that long-term exposure of female rats to Topamax causes adverse effects on the reproductive system and fertility.

CONCLUSION: The results of the current study suggest that ingestion of Topamax by adult female rats causes adverse effects on fertility and reproduction....

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Comparative Study 2005; 26(6): 780-788 PubMed PMID: 16380692 Citation  Keywords:  Age Factors, Animals, Animals, Newborn:physiology, Body Weight:physiology, Corticosterone:blood, Female, Germ Cells:cytology, Hydroxysteroid Dehydrogenases:metabolism, Hypothyroidism:chemically induced, Luteinizing Hormone:blood, Male, Organ Size, Pregnan.   

OBJECTIVE: Effects of transient neonatal hypothyroidism (HPOT) on adult testis size and serum hormone profiles were evaluated in the Charles foster strain of rats, maintained under the temperature of 21 degrees C (HPOTL) or of 34 degrees C (HPOTH).

METHODS: Hypothyroidism was induced in suckling pups in preweanling period (1-21 days), by administering 0.1% 6-propyl-2-thiouracil in drinking water to mothers. Body mass and testis characteristics, the steroidogenic potential [measured by histochemical localization of 3alpha-, 3beta- and 17beta-hydroxysteroid dehydrogenases (HSDHs)] and serum concentrations of thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), luteinizing hormone (LH), testosterone (T) and corticosterone (Cort) were evaluated on the 35th, 45th, 60th and 90th day of age.

RESULTS: The HPOTH rats showed lower testis masses, while the HPOTL rats showed higher testis masses and lower body masses after 90 days. Histologically, the testes of the HPOTH rats demonstrated increased germ cell degeneration after 35 and 45 days and reduced tubular size, germ cell numbers and sperm density after 90 days. In contrast, the testes of the HPOTL rats showed reduced tubular diameters after 35 and 45 days, and increased tubular diameters, germ cell numbers and sperm density after 90 days. Serum TSH, T3, T4, LH and T concentrations and 3beta- and 17beta-HSDH activities were reduced in both groups of the HPOT rats after 35 and 45 days. Intratubular steroidogenesis and a prominent triangle up5 pathway were also found in the HPOT animals.

CONCLUSION: The temperature has a definite influence on the thyroid hormone action, postnatal growth and function of rat testes....

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Comparative Study 2005; 26(6): 806-810 PubMed PMID: 16380687 Citation  Keywords:  Animals, Glutathione:metabolism, Hyperthyroidism:chemically induced, Kidney:metabolism, Lipid Peroxidation, Male, Malondialdehyde:metabolism, Melatonin:metabolism, Oxidative Stress:physiology, Rats, Rats, Sprague-Dawley, Testis:metabolism, Thyroxine,.   

OBJECTIVE: The present study aimed at determining how 3-week intraperitoneal melatonin administration affected oxidative stress caused by experimental hyperthyroidism.

MATERIALS AND METHODS: The study was conducted on 30 male rats of Sprague-Dawley species. The experimental animals were divided to 3 groups (control, hyperthyroidism and hyperthyroidism+melatonin). The supplementation was continued for 3 weeks after which the animals were sacrificed and tissue malondyaldehyde (MDA) and glutathione (GSH) levels were determined.

RESULTS: MDA levels in kidney and testis tissues in hyperthyroidism group were higher than those in control and hyperthyroidism+melatonin administered groups (p<0.001) and levels in hyperthyroidism+melatonin administered group were higher than those in the control group (p<0.001). The highest GSH levels were obtained in hyperthyroidism+melatonin-administered group (p<0.001) and GSH levels in hyperthyroidism group were higher than those in the control group (p<0.001).

CONCLUSION: Results of the study demonstrate that hyperthyroidism induced by 3-week L-thyroxine administration increased oxidative stress in kidney and testis tissues and that although melatonin administration inhibited this stress to a certain extent, it could not bring the stress down to the level in controls....

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Journal Article 2005; 26(6): 835-838 PubMed PMID: 16380681 Citation  Keywords:  Age Distribution, Child, Child, Preschool, Cough:chemically induced, Cross-Sectional Studies, Female, Fever:chemically induced, Hospitals, Teaching:statistics & numerical data, Humans, Incidence, Infant, Jordan:epidemiology, Kerosene:poisoning, Male, Pati.   

PURPOSE: Poisoning due to drugs is influenced to a large extent by the population's socioeconomic and cultural status. The purpose of our study was to determine and present the pattern of poisoning with kerosene in Princess Rahmat hospital, Irbid, Jordan, and to assess the effects of variables such as age, season, sex and agent on poisoning frequency in Princess Rahmat hospital, northern Jordan.

METHODS: This retrospective cross-sectional study was performed on 122 cases of poisoning with kerosene who were hospitalized in Princess Rahmat hospital, northern Jordan, during a six-year period from 1996 to 2001. The data collected include: age, sex, seasonal variation, material ingested, symptomatic or not on admission, time and place of ingestion, history of similar problem among the patient or his siblings, whether vomiting was induced by the parent before seeking medical help or not and the outcome regarding mortality and morbidity. Chi-square and values were considered for the statistical analysis.

RESULTS: In a 6-year prospective study of kerosene poisoning in children admitted to the Rahmat Hospital, between January 1996 and December 2001, a total of 122 children (under 11 years of age). Among the children 48 (39.3%) were girls and 74 (60.6%) were boys. Majority (80.1%) were below 2 years. The largest group of patients was admitted during the summer months. The most commonly observed symptoms were cough (67.2%), tachypnea (56.5%), fever (54.1%), and vomiting (27.8%). About one third of the patients showed signs of central nervous system (CNS) impairment, including drowsiness, restlessness, stupor, and convulsions.

CONCLUSIONS: 1) There is a higher risk of kerosene poisoning during the hot months of the year; 2) the respiratory system is the main target organ affected; 3) pneumonia is in most cases interstitial and bilateral; 4) vomiting after hydrocarbon ingestion is related to the rate of development of pneumonia; 5) symptoms of CNS impairment were correlated with hypoxemia, pneumonia, and fever; and 6) CNS toxicity may occur without hypoxemia, concurrent pulmonary pathology, or other pathology....

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Comparative Study 2005; 26(6): 739-744 PubMed PMID: 16380673 Citation  Keywords:  Analysis of Variance, Animals, Arthritis, Experimental:chemically induced, Arthritis, Rheumatoid:enzymology, Chemokine CCL5:genetics, Collagen, Cytokines:genetics, Disease Models, Animal, Down-Regulation, Female, Interleukin-1:genetics, Interleukin-6:gene.   

OBJECTIVE: To observe the effects and mechanisms of beta-endorphin (beta-END) preventing collagen induced arthritis (CIA) by neuroimmuno-regulating pathway.

METHODS: Female wistar (Ws) rats were used in this study. CIA was induced by Native bovine type II collagen emulsified with complete Freund's adjuvant (CFA). Beta-END was administered i.p. to CIA rats every other day from the 14th day (secondary immunization) to the 35th day after primary immunization. Clinical assessments were performed by two independent, blinded examiners every other day. Pathological and radiological observations were taken on the 35th day after the primary immunization. Tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), interleukin-6 (IL-6), regulated upon activation, normal T-cell expressed and secreted (RANTES), inducible NO syntheses (iNOS), matrix metalloproteinase-2 (MMP-2) and MMP-9 mRNA expression of synovium tissues of CIA rats was estimated by quantitative RT-PCR. The frequency of spleen Th1 and Th2 cells were assessed by fluorescence activated cell sorter (FACS) assay.

RESULTS: Clinical manifestation of rats with CIA were significantly abrogated or ameliorated by treatment with beta-END. Beta-END treatment in vivo could down-regulate mRNA expression of several pro-inflammatory cytokines, chemokines and MMPs in CIA synovial, and polarize Th1/Th2 balance to Th2.

CONCLUSION: Beta-END alleviates CIA through both depressing Th1 responses and down-regulating proinflammatory and other rheumatic factors, suggesting beta-END is a promising anti-inflammatory and anti-rheumatic agent in treating CIA....

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Journal Article 2005; 26(5): 439-446 PubMed PMID: 16264412 Citation  Keywords:  Autistic Disorder:chemically induced, Autoimmune Diseases:chemically induced, Chelating Agents:therapeutic use, Child, Humans, Inflammation:chemically induced, Mercury:analysis, Mercury Poisoning:epidemiology,.   

: The causes of autism and neurodevelopmental disorders are unknown. Genetic and environmental risk factors seem to be involved. Because of an observed increase in autism in the last decades, which parallels cumulative mercury exposure, it was proposed that autism may be in part caused by mercury. We review the evidence for this proposal. Several epidemiological studies failed to find a correlation between mercury exposure through thimerosal, a preservative used in vaccines, and the risk of autism. Recently, it was found that autistic children had a higher mercury exposure during pregnancy due to maternal dental amalgam and thimerosal-containing immunoglobulin shots. It was hypothesized that children with autism have a decreased detoxification capacity due to genetic polymorphism. In vitro, mercury and thimerosal in levels found several days after vaccination inhibit methionine synthetase (MS) by 50%. Normal function of MS is crucial in biochemical steps necessary for brain development, attention and production of glutathione, an important antioxidative and detoxifying agent. Repetitive doses of thimerosal leads to neurobehavioral deteriorations in autoimmune susceptible mice, increased oxidative stress and decreased intracellular levels of glutathione in vitro. Subsequently, autistic children have significantly decreased level of reduced glutathione. Promising treatments of autism involve detoxification of mercury, and supplementation of deficient metabolites....

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Journal Article 2005; 26(5): 581-592 PubMed PMID: 16264397 Citation  Keywords:  Animals, Arylalkylamine N-Acetyltransferase:antagonists & inhibitors, Data Interpretation, Statistical, Depression, Chemical, Female, In Vitro Techniques, Melatonin:metabolism, Norepinephrine:antagonists & inhibitors, Perfusion, Pineal Gland:cytology, Rad.   

OBJECTIVES: Cell-permeable and specific inhibitors of melatonin secretion are sill lacking among tools of the pineal research. Recently, a large effort has been made in the development of arylalkylamine N-acetyltransferase inhibitors, but in most cases the new drugs were tested exclusively using cell-free assays or non-pineal cells. The aim of the present study was to characterize the effect of N-bromoacetyltryptamine (BAT), the first synthesized cell-permeable inhibitor of arylalkylamine N - acetyltransferase, on melatonin secretion from rat and pig pineal glands.

METHODS: The studies were performed in the superfusion cultures of rat and pig pineal explants. Melatonin secretion was determined by radioimmunoassay (RIA).

RESULTS: BAT strongly inhibited the non-stimulated and norepinephrine - stimulated melatonin secretion from the pig and rat pineal explants, with ED50 0.3 - 0.7 microM. The adrenergic stimulation did not modify significantly the inhibitory potency of BAT on the melatonin release. The decline in melatonin secretion induced by the BAT - treatment was biphasic in both rat and pig pinealocytes, with an initial rapid phase followed by a slow one. The half-time of BAT-induced decline in the non - stimulated and norepinephrine-stimulated melatonin secretion was ca. 25 - 35 minutes. The inhibitory effect of BAT was reversible in pinealocytes of both investigated mammals.

CONCLUSIONS: The results show that BAT is a potent and reversible inhibitor of the melatonin secretion in the mammalian pineal gland and open the way for the use of this inhibitor in investigations on the pinealocyte physiology performed in vitro....

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