Physiological inhibition of growth hormone secretion by both insulin‐like growth factors‐I and ‐II in chickens

1. The role of both insulin‐like growth factors (IGF)‐I and ‐II in regulation of growth hormone (GH) secretion in chickens was examined. Seven‐week‐old male broiler chickens were injected intravenously (iv) with recombinant human IGF‐I or IGF‐II or specific anti‐IGF‐I or IGF‐II immunoglobulins. Blood samples were taken before treatment and at 15 min intervals afterwards for 1 h. Controls received saline iv.

2. Both IGF‐I and IGF‐II administration resulted in a rapid, significant decrease in plasma GH concentrations, but the concentrations of both triiodothyronine and thyroxine remained unchanged.

3. Immunisation against both IGF‐I and IGF‐II produced a significant elevation in plasma GH.

4. These data show that both IGFs can regulate GH concentrations in birds. Furthermore, the immunoneu‐tralisation data suggest that these hormones have a physiological role in the regulation of GH secretion.     

The effects of oral vitamin E on induction and consequence of experimental diabetes mellitus in rats

Streptozotocin destroys the beta-cells of pancreas by generation of reactive oxygen species and vitamin E has documented antioxidant properties. To evaluate the preventive effect of vitamin E on induction of diabetes by streptozotocin and effect of oral vitamin E consumption on carbohydrate and lipid metabolism, forty male Wistar rats divided randomly to control, E1, E2 and E3 groups. The diet of E1, E2 and E3 groups were supplemented with 1, 2 and 4 g kg(-1) of vitamin E, respectively. Four days later all rats were made diabetic by IP injection of 45 mg kg-' streptozotocin and blood glucose was measured 72 h later to determine the severity of blood glucose elevation. Glycosylated hemoglobin, triglyceride, total cholesterol and HDL-c were measured and LDL-c and VIDL-c calculated in plasma of 6 diabetic rats with glucose more than 200 mg dL(-1) in each groups 21 days after streptozotocin injection. Vitamin E had no effect on diabetes induction by streptozotocin, but elevation of glycosylated Hb and reduction of LDL-c in group E3 were significant. Vitamin E also increased HDL-c although it was not statistically significant. We suggest that oral vitamin E consumption may have some beneficial effect on the correction of lipid metabolism disorders of diabetes, although it may worsen carbohydrate metabolism in mild diabetes.     

Effect of Monensin on Serum Lipoproteins, Triglycerides, Cholesterol and Total Lipids of Periparturient Dairy Cows

Serum concentrations of very low-density lipoproteins (VLDL), low-density lipoproteins (LDL), high-density lipoproteins (HDL), triglycerides, cholesterol, and total lipids of a group of monensin-treated cows (n = 7) were compared with those of a control group (n = 6) from about 10 days before calving to 45 days postpartum. Monensin was fed in the diet from about 20 days before predicted calving date to 45 days after parturition. Blood samples were obtained on days 20 and 10 before predicted calving, and on days 4, 15, 25 (phase I), and days 35 and 45 (phase II) post calving. Cholesterol (p = 0.046) and total lipids (p = 0.003) were lower in the treatment group 10 days before calving. Concentrations of serum triglycerides and VLDL (p = 0.017), and that of LDL (p = 0.032) were significantly higher in the treatment group in phase I postpartum. No significant difference was detected between groups during phase II. Comparison of the entire length of the trial showed higher concentrations of triglycerides and VLDL in the treatment group (p = 0.009). It is concluded that monensin is effective in increasing secretion of triglyceride-rich lipoproteins from the liver during the postpartum transition period of dairy cows. This may be effective in reducing the intensity of hepatic lipidosis and the incidence of periparturient diseases resulting from disturbances in energy metabolism.     

Standardization of the outbred BALB/c mice as a suitable animal model for <Emphasis Type="BoldItalic">Besnoitia caprae</Emphasis> studies

The Apicomplexan parasite Besnoitia caprae infects wild and domestic goats. Knowledge on Besnoitia caprae specially an optimized animal model is sparse. Experimental infections with tachyzoites of BC-Pars obtained from BALB/c mice were conducted in outbred mice to determine the infectivity and LD50 of Besnoitia caprae. Six groups of five mice were intraperitoneally infected with 12.5 × 10³, 25 × 10³, 5 × 10⁴, 1 × 10⁵ and 2 × 10⁵ tachyzoites and a control inoculum of DMEM, respectively. Although morbidity and mortality were observed in all groups, two mice in the 12.5 × 10³ group showed alopecia and skin lesions on 60 days post-infection (DPI). Histopathological and molecular examination of skins confirmed B. caprae infection. The LD₅₀ was calculated as 25 × 10^3.2 tachyzoites per mouse. The results indicate that outbred BALB/c mice can be used as a suitable model of besnoitiosis and to screen candidate treatments and to test the efficacy of vaccines for besnoitiosis.     

Effect of interceptor drainage on phosphorus transport and soil chemical characteristics under different cultivation conditions

Paddy and Water Environment - Drainage is a profitable water management operation in waterlogged soils, particularly in hot, arid environments where waterlogging is caused by irrigation and salts...     

Organic amendments and urea nitrogen effects the growth and nutrient content of fenugreek (Trigonella foenumgraecum) and goat pea (Securigera securidaca)

Abstract

In Iran, the recent spike in herbal medicines has led to a corresponding price increase. Therefore, these montane species are now widely field cultivated. Medicinal plant consumers strongly prefer organically grown plants, and farmers are responding to this market. However, the effects of organic amendments on medicinal plant nutrient content and yield have been poorly studied. Therefore, this study measured the effects of different organic treatments on the growth of fenugreek and goat pea. Plants were grown to compare the effects of composted municipal waste (CMW), vermicompost (VC), and urea nitrogen (N) to untreated field soil (C0). Germination percentage was significantly higher in urea N (76.5%), CMW (75.5%), and VC (51.6%) compared to C0 (36.3%). Fenugreek performed better in organic amendment treatments than goat pea. Urea N also increased fenugreek plant dry matter significantly compared to C0, but this increment was not as high as CMW or VC. Plants grown in VC had higher whole plant N content (3.2%) than those grown in CMW (2.8%) and plants grown in urea N (2.6%). Plants treated with CMW (8613?mg kg^?1) and VC (8503?mg kg^?1) had a significantly higher P content than those treated with N (7430?mg kg^?1) or C0 control grown (7236?mg kg^?1). Application of VC significantly increased plant K content (2483?mg kg^?1) compared to CMW (1850?mg kg^?1), N (1750?mg kg^?1), and C0 control (1716?mg kg^?1). Even without fertilization, both plant species contained a considerable amount of micronutrient elements.     

Exploring the potential for top-dressing bread wheat with ammonium chloride to minimize grain yield losses under drought

The frequency and severity of drought is predicted to rise in many parts of the world. Considering that drought is the main constraint on rain-fed wheat crop production, both agronomic and genetic measures have been taken to minimize yield losses under drought. Beyond its role as a micronutrient, chloride also acts as an osmoticum, implicated in the regulation of stomatal aperture. This study explores the potential for chloride fertilization of Australian bread wheat (Triticum aestivum L.) to minimize grain yield losses caused by drought stress. For this, two drought-tolerant commercial genotypes (Mace and Gladius) and a well-studied drought-tolerant genotype used in wheat breeding (RAC875) were treated with ammonium chloride, potassium chloride, or ammonium bicarbonate, the latter two treatments served as controls for chloride and ammonium, respectively. Plants were grown under either a watered or water-restricted (drought) regime. The genotype RAC875 was found to accumulate leaf chloride at a significantly higher level than the other genotypes under optimal growth conditions. Under drought conditions, top-dressing RAC875 plants with ammonium chloride resulted in up to a 2.5-fold increase in grain number and this effect was not seen when plants were top-dressed with either of the control fertilizers. The ammonium chloride treatment also minimized losses of grain yield in RAC875 plants grown under drought. Treatment effects were accompanied by an increase in stomatal conductance. These results collectively suggest that the compound fertilizer ammonium chloride can improve drought tolerance of wheat.     

Antibiotics,Penicillin and Sreptomycin improve semen quality indices of endangered Caspian brown trout,Salmo trutta caspius (Kessler, 1870) during in vitro short‐term storage

In this study, we examined the effects of 500 IU mL^?1 penicillin + 500 μg mL^?1 streptomycin sulphate on semen quality indices of endangered caspian brown during 12 days short‐term storage at 4°C. Twenty‐four millilitre semen samples with good quality were considered for the experiment. The semen samples were then stored in the presence and absence of 500 IU mL^?1 penicillin + 500 μg mL^?1 streptomycin sulphate. The semen quality parameters including percentage and duration of sperm motility were measured 0, 3, 6, 9 and 12 days after storage. In the antibiotic receiving group, the values of percentage and duration of sperm motility reduced 3 and 6 days after storage respectively and reduced to lowest levels at day 12. In the antibiotic‐free group, the duration and percentage of sperm motility decreased significantly after 3 days of storage and reached to lowest values at day 12. Also, percentage and duration of sperm motility in each storage time were significantly higher in the antibiotic receiving group than in the antibiotic‐free group. The overall values of percentage and duration of sperm motility for all storage periods were higher in the antibiotic receiving group than in the antibiotic‐free group. In conclusion, our results demonstrated that 500 IU mL^?1 penicillin + 500 μg mL^?1 streptomycin sulphate improves the viability of caspian brown trout during short‐term storage.     

The effects of altered ultrasound parameters on the recovery of sciatic nerve injury

Background: Initial studies have shown that low-energy ultrasound stimulates living tissue cells to reduce regeneration or speed up their recovery. The purpose of this study was to examine the effects of various ultrasound parameters on the speed of recovery in injured sciatic nerves NMRI.Methods: NMRI mice (n = 200) with injured left paw, caused by crushing their sciatic nerves, were randomly selected. The animals were exposed to ultrasound radiation with various frequencies, intensities, and exposure time. They were allocated into 20 groups (19 treatment and 1 control groups). Sciatic functional index (SFI) test was used to evaluate the difference between the groups with respect to functional efficiency of the sciatic nerve and its recovery. SFI ، (P=0.000).Results: The results of SFI test obtained from the 14^th day showed a significant difference among the groups (P<0.05). On the 14^th day after treatment, one of the groups (US11) recovered up to 90%..Conclusion: Altered ultrasound exposure parameters had more favorable outcomes compared with our previous work.Key Words: Sciatic nerve, Ultrasonic therapy, Regeneration     

Distribution and tensile strength of Hornbeam (Carpinus betulus) roots growing on slopes of Caspian Forests, Iran

Biomechanical characteristics of the root system of hornbeam (Carpinus betulus) were assessed by measuring Root Area Ratio (RAR) values and tensile strength of root specimens of eight hornbeam trees growing on hilly terrain of Northern Iran. RAR values of the roots were obtained using profile trenching method at soil depth of the top 0.1 m. In total 123 root specimens were analyzed for tensile strength. Results indicate that in general, RAR decreases with depth, following a power function. The RAR values in up and down slopes have no significant statistical differences. In most cases, the maximum RAR values were located in soil depth of the top 0.1 m, with maximum rooting depth at about 0.75 m. The minimum and maximum RAR values along the profiles were 0.004% and 6.431% for down slope and 0.004% and 3.995% for up slope, respectively. The number of roots in the up and down slope trenches was not significantly different. In the same manner as for RAR, number of roots distributing with depth was satisfactorily approximated a power function. The penetration depths of above 90 percent of the roots were at soil depths of 50 cm and 60 cm for up and down slopes, respectively. Results of Spearman’s bivariate correlation showed no significant correlation between the RAR value with tree diameter and gradient of slope and number of roots. The mean value of root tensile strength was 31.51 ± 1.05 MPa and root tensile strength decreased with the increase in root diameter, following a power law equation. Using ANCOVA, we found intraspecies variation of tensile strength. Biography: Ehsan Abdi (1978– ), Male, Ph.D candidate, in the Department of Forestry, University of Tehran, Karaj 31585-3314, Iran.