Temporal trends and prediction of bovine tuberculosis: a time series analysis in the North-East of Iran.

Background: Bovine tuberculosis (BTB) is a disease with high economic relevance. Aims: This study aimed to determine a fast alert surveillance system for bTB before the outbreak in the epidemic region of Iran. Methods: This cross-sectional study was conducted using the Auto-Regressive Integrated Moving Average (ARIMA) model for monthly bTB detections (reactors). These reactor cases result from the positive Tuberculin Purified Protein Derivative (PPD) test on cattle farms for the period between April 2007 and March 2019 in Razavi Khorasan province. Autocorrelation functions (ACF) and partial autocorrelation functions (PACF) plots were used to determine model parameters. The Akaike Information Criteria (AIC) were employed to select the best-fitted model. The root mean square error (RMSE) was applied for the evaluation of the models. Then, the best-fitted model was hired to predict the cases for 12 oncoming months. The data were analysed by STATA (ver. 14) software with a significant level at P≤0.05. Results: ARIMA (3, 0, 3) 12 was introduced as a recommended fitted model according to white noise residual test (Q=22.87 and P=0.98), lower AIC (541.85), and more precise model RMSE (1.50). However, the forecast values were more than the observed values. Conclusion: The application and interpretation of ARIMA models are straightforward, and may be used as immediate tools for monitoring systems. However, we proposed an Auto-Regressive Integrated Moving Average with Exogenous Input (ARIMAX) model with some measurable exotic factors such as economic fluctuations, climate changes, and pulmonary tuberculosis to introduce a more precise and accurate model for the fast alert surveillance system.

THE EFFECT OF MELATONIN AGAINST GASTRIC OXIDATIVE STRESS AND DYSLIPIDEMIA IN STREPTOZOTOCIN-INDUCED DIABETIC RATS.

OBJECTIVE: The aim of this study was to evaluate the possible protective effects of MT against gastric oxidative stress and dyslipidemia in streptozotocin (STZ) - induced diabetic rats. METHODS: Forty male Wistar rats were randomly divided into five groups: control, diabetic, MT 5 mg/kg+ STZ, MT 10 mg/kg+ STZ and MT 20 mg/kg+ STZ. STZ (60 mg/kg) was intraperitoneally (ip) injected as a single dose for diabetes induction. One week after STZ administration, MT was injected daily as ip for 14 days. The levels of malondialdehyde (MDA), total thiol and glutathione, as well as superoxide dismutase (SOD) and catalase activities were measured in gastric tissue. Serum concentrations of triglycerides (TG), total cholesterol (TC), high density lipoprotein (HDL) and low density lipoprotein (LDL) were also determined. RESULTS: Serum glucose significantly increased in diabetic group compared to control group. STZ induced a significant decrease in gastric tissue levels of total thiol, glutathione, catalase and SOD activities and a significant increase in MDA concentration. In diabetic rats, serum TG, LDL and TC were significantly higher and HDL was significantly lower than in the control group. Treatment of diabetic rats with MT caused a significant increase in gastric total thiol content and glutathione concentration as well as SOD and catalase activities. Gastric MDA concentration and serum LDL, TG and TC were significantly lower in MT-treated groups when compared with diabetic group. CONCLUSION: These data suggested that MT has a therapeutic effect on gastric oxidative damage and dyslipidemia induced by diabetes that possibly may be due to its antioxidant effects.

Crocin improves spatial learning and memory deficits in the Morris water maze via attenuating cortical oxidative damage in diabetic rats.

The purpose of the current study was to examine the influence of crocin on improving spatial memory deficits and cerebral oxidative damage in streptozotocin-induced diabetic rats. Crocin was administered intraperitoneally daily at doses of 15, 30 and 60mg/kg for 6 weeks. Spatial memory performance was measured in rats by the Morris water maze paradigm. Lipid peroxidation and total thiol levels as parameters of oxidative stress were assessed in the cerebral cortex at the end of week 6. Diabetic rats showed spatial learning and memory deficits in the Morris water maze which was accompanied by increased lipid peroxidation levels in the cerebral cortex. By contrast, chronic treatment with crocin (15, 30 and 60mg/kg, ip, 6 weeks) improved cognitive performance and lowered hyperglycaemia and oxidative stress in diabetic rats. In conclusion, the results suggest that beneficial effects of crocin on streptozotocin-induced memory dysfunction may be attributed to its antidiabetic and antioxidant activity, which could find clinical use in treating cognitive dysfunction in diabetics.

Proinsulin C-peptide inhibits lipolysis in diabetic rat adipose tissue through phosphodiestrase-3B enzyme.

We have previously reported that C-peptide modulates insulin-mediated inhibition of lipolysis and glucose consumption but has no significant effects per se on adipose tissue of normal rats. It has been repeatedly observed that certain actions of C-peptide are restricted to the diabetic states. In the present study, therefore, we examined whether C-peptide alters lipolysis in adipose tissue of diabetic rats. Rats were rendered diabetic by streptozotocin and divided into 2 groups; insulin treated and untreated. Retroperitoneal adipose tissue was excised aseptically, subjected to organ culture and incubated with rat C-peptide, insulin, or a combination of both peptides in the presence or absence of isoproterenol. Tissue lipolysis was assessed by the rate of glycerol release into the culture media. The cultures were pretreated with cilostamide, a phosphodiesterase-3B enzyme inhibitor, when the role of this enzyme was to be examined. C-Peptide on its own, like insulin, significantly inhibited isoproterenol-stimulated lipolysis in the adipose tissue of untreated diabetic rats. The effect was enhanced by a combination of C-peptide and insulin. Notably, the C-peptide's effect was totally blocked in the presence of cilostamide. In the adipose tissue of insulin treated rats, however, C-peptide failed to show any significant antilipolytic effects. These data show that C-peptide has the potential to act, conditionally, as an antilipolytic hormone by activating phosphodiesterase-3B and suggest that the action may contribute to the C-peptide's beneficial effects on diabetes-induced complications.

Inducible nitric oxide synthase inhibitor aminoguanidine, differently affects Morris water maze tasks of ovariectomized and naïve female rats.

The role of ovarian hormones, nitric oxide, and their interaction on learning and memory has been widely investigated. The objective of present study was to investigate different effects of chronic administration of inducible nitric oxide synthase inhibitor, aminoguanidine (AM) on learning and memory of ovariectomized (OVX) and naïve (Sham) female rats. Thirty-two rats were divided into four groups: 1) Sham, 2) OVX, 3) Sham-AM and 4) OVX-AM. The animals of Sham-AM and OVX-AM chronically received 100 mg/kg/day of aminoguanidine during 8 weeks before 5 test days. The animals in Sham and OVX groups received 1 ml/kg saline instead of aminoguanidine. The animals were tested in Morris water maze and the escape latency and traveled path to reach the platform were compared between groups. On the fifth day, the platform was removed, and the animals were allowed to swim for 60 s ( prob trial). The time spent in the target quadrant (Q1) was compared between groups.Results showed that the escape latency and traveled path in OVX group were significantly higher than in the Sham group (p<0.01). Both escape latency and traveled path in the Sham-AM group was significantly higher than in the Sham group (p<0.01) however, there was no significant difference between OVX-AM and OVX groups.The time spent by the animals of OVX group in the target quadrant (Q1) during the probe trial was significantly lower than that in the Sham group (p<0.01). The animals of the Sham-AM group spent shorter times in the target quadrant in comparison with the Sham group (p<0.01). There was no significant difference between the OVX and OVX-AM groups in the time spent in tarthe get quadrant. It is concluded that the effect of aminoguanidine on learning and memory is different in the presence or absence of ovarian hormones but it needs further investigation.

The effect of L-arginine on Morris water maze tasks of ovariectomized rats.

The role of ovarian hormones, nitric oxide, and their interaction on learning and memory has been widely investigated. The present study was carried out to evaluate the effect of acute (A) and chronic (C) L-arginine (L-Arg) administration on learning and memory in ovariectomized (OVx) rats. Forty-five rats were divided into six groups: 1) sham, 2) OVx, 3) sham-L-Arg-A, 4) OVx-L-Arg-A, 5) sham-L-Arg-C, 6) OVx-L-Arg-C. The animals of sham-L-Arg-A and OVx-L-Arg-A were acutely treated with 500 mg/kg of L-Arg during 5 test days. Sham-L-Arg-C and OVx-L-Arg-C chronically received 500 mg/kg/day of L-Arg during 8 weeks before 5 test days. The animals in sham and OVx groups received 1 ml/kg saline instead of L-Arg. At the end of the experiment, the animals were tested in Morris water maze and the escape latency and traveled path to reach the platform were compared between groups. Results showed that the escape latency and traveled path in OVx group were significantly higher than in sham group ( p <0.05). The animals in OVx-L-Arg-A group had significantly lower traveled path length and escape latency compared to OVx group ( p <0.001). Chronic treatment by L-Arg had no significant effect on learning and memory in OVx and sham-operated animals. It seems that L-Arg has a role in Morris water maze tasks disturbances in OVx rats but it needs to be further investigated.