Effects of L-ascorbic acid on growth, non-specific immunity, antioxidant capacity, and intestinal and hepatopancreatic histology of red swamp crayfish, Procambarus clarkii.

This study investigated the dietary effects of coated L-ascorbic acid (LA) on growth, feed utilization, survival, serum biochemical indices, immunity, antioxidant capacity, and intestinal and hepatopancreatic histology of the pre-adult red swamp crayfish. Four isoproteinous and isolipidic diets were formulated to contain several LA levels as 0, 1300, 1600, and 1900 mg/kg and designated as control (LA0), LA13, LA16, and LA19, respectively. However, the analyzed LA concentrations in diets were 0.00, 199.57, 360.45, and 487.50 mg/kg in LA0, LA13, LA16, and LA19, respectively. Triplicate treatments of crayfish (21.60 ± 0.14 g) were fed the test diets and reared in fiberglass tanks with a density of 20 individuals per each for eight weeks. Results revealed that all LA treatments had significantly enhanced growth performance compared to the control. Of interest, the LA16 treatment recorded the highest final tank biomass, biomass gain, total feed intake, condition factor, and muscle yield among the other treatments. The tank feed conversion ratio was significantly decreased in LA treatments compared to the control. Moreover, dietary LA16 and LA19 had significantly higher survival rates (93.3%) compared to (85.0%) in the LA0 group. All dietary doses of LA significantly increased serum parameters (total protein, albumin, globulin, lysozyme activity) and respiratory burst activity compared to the LA0 treatment. Dietary LA16 significantly boosted the hepatopancreatic antioxidant capacity, manifested by decreased malondialdehyde concentrations, increased catalase, superoxide dismutase, and glutathione peroxidase enzyme activities, and reduced glutathione content compared to the LA-free diet. A normal histoarchitecture of the hepatopancreatic tubules was found in all LA treatments except with some minor degenerative changes in the tubular lumen, and hepatopancreatic cells associated with enlarged nuclei were found in the LA19. However, normal intestinal histoarchitecture was found in all treatments with no recorded intestinal lesions. Of interest, the polynomial regression performed on the analyzed LA concentrations suggested that 380 mg/kg would be suitable to provide maximal biomass gain for pre-adult crayfish. In conclusion, results revealed that coated LA could enhance the growth, immunity, and antioxidant capacity of pre-adult red swamp crayfish, suggesting its potential as a functional and necessary micronutrient for crayfish diets.

Contamination of selected heavy metals in Limnothrissa miodon (Boulenger, 1906) in the four strata of Lake Kariba Zambia: are the consumers at risk?

Pollution of aquatic ecosystems is one of the major challenges affecting many countries of the world. Heavy metal pollutants, in particular, threaten the life of aquatic organisms (fauna and flora) and, more importantly, humans who consume aquatic products as a critical source of proteins. In the present study, the concentrations of selected heavy metals (cobalt- Co, Chromium-Cr, nickel- Ni and manganese- Mn) in Limnothrissa miodon, locally known as 'Kapenta' were assessed using the Microwave Plasma Atomic Emission Spectrometer (MP AES) 4200 at the Zambia Agricultural Research Institute (ZARI). The fish was collected from Lake Kariba, Zambia, which is divided into four fisheries management strata (I, II, III, and IV). The health risks to consumers were evaluated using the Estimated Daily Intake (EDI), Target Hazard Quotient (THQ) and Hazard Index (HI). Analysis of variance (ANOVA) was used to assess the difference in the means of heavy metal concentration across the four strata for each element. The concentrations of all the heavy metal elements were within the permissible limits considered to be safe for human consumption based on the Food and Agriculture Organization (FAO) standards. However, the concentration of individual heavy metal elements varied significantly across the strata with stratum I and II showing higher levels in general except for Mn which was highest in stratum II and III compared with the other strata. Furthermore, Mn concentration was the highest in all the strata and the highest concentration was observed in the fish from stratum II. The EDIs, THQs and HIs of each heavy metal element did not show any threat to consumers of the fish from the lake. Further studies are required to better understand the potential sources of heavy metals and to regularly monitor existing activities that may elevate the concentration levels.

Maternal obesity and neonatal congenital cardiovascular defects.

OBJECTIVE: To determine whether isolated congenital heart defects (CHDs) were associated with maternal obesity. METHOD: In a retrospective study we compared the incidence and severity of isolated CHDs in the offspring of 428 women divided into 3 groups, one of women of normal weight (n=141), one of obese women (n=228), and one of morbidly obese women (n=59) according to their body mass index. RESULTS: There were 143 mild (66.8%), 44 moderate (20.6%), and 27 complex (12.6%) forms of CHDs in the offspring and septal defects were the most common (61.7%). No significant differences were found among the 3 groups of women regarding the type or severity of CHDs in their respective offspring, or the corrective cardiac surgery required. CONCLUSION: No association was found between maternal weight and isolated CHDs in the offspring.

Review of nonsurgical and surgical treatment and the role of insulin-sensitizing agents in the management of infertile women with polycystic ovary syndrome.

OBJECTIVES: To review the nonsurgical and surgical treatment and the role of insulin-sensitizing agents in the management of anovulatory infertile women with polycystic ovary syndrome (PCOS). MATERIALS AND METHODS: The search term of subfertile women with anovulation and PCOS was used for identification of randomized controlled trials. Nonrandomized controlled studies were identified through computer MEDLINE and EMBASE searches for the years 1980-2002. RESULTS: For obese PCOS women weight loss of > 5% of pretreatment weight restores menstrual regularity in 89%, of whom 30% achieved spontaneous pregnancy. It was estimated that 75-80% of anovulatory PCOS women will respond to clomiphene citrate (CC) and 35-50% will achieve pregnancy. For CC-resistant PCOS women (20-25%), CC + metformin (1.5 g/day) for 3-6 months has a 70% chance of restoration of regular menses and ovulation, and a 23% chance of pregnancy. Laparoscopic ovarian drilling (LOD) can be offered to CC-resistant PCOS women. There was no statistically significant difference in the ovulation rate following LOD with electrocoagulation and laser [83% vs. 77.5%; odds ratio (OR) 1.4; 95% CI 0.9-2.1], while there was a significantly higher cumulative pregnancy rate at 12 months after surgery (65% vs. 54.5%; OR 1.5; 95% CI 1.1-2.1). CONCLUSION: Diet and exercise followed by CC should be used for nonsurgical ovulation induction. For CC-resistant PCOS women, metformin may be included in a stepwise approach before a surgical approach. LOD with electrocautery is superior to laser drilling and gonadotropin therapy.

Quick gene expression profiling of promyelocytic cell line HL-60.

OBJECTIVE: A number of techniques have been developed to perform gene expression profiling. We report preliminary results from our exploratory study, using sequential analysis of gene expression (SAGE) technique, to profile the undifferentiated and differentiated HL-60 cells in line with our interest to characterize the cancer phenotype. The aim of the study is to evaluate the technique and to understand the molecular bases of these 2 states of cells. METHODS: HL-60 cells were differentiated after treatment with dimethyl sulfoxide. Tag libraries were prepared from the messenger RNAs of the undifferentiated and differentiated cells according to the SAGE protocol. The search for genes corresponding to the tags was carried out using SAGE software. The tags and the genes from the 2 libraries were compared for their levels of expression. The study was carried out at the King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia during the year 2001. RESULTS: A comparison of tags from the 2 libraries revealed that 151 tags corresponding to 57 genes expressed differentially: 60 tags were elevated and 59 were repressed in the undifferentiated cells. Thirty-two tags were equally expressed in both types of cells. Of the corresponding genes, 25 were expressed at higher, 17 at lower, while 15 were expressed at comparable levels in both cell types. In the profile of undifferentiated cells, the genes involved in mitochondrial function and protein synthesis were prominent, while in the differentiated cells, the genes coding for proteins associated with cell membranes, signal transduction and for cell specific functions were prominent. The genes, expressed equally in both the cell types, were concerned with the maintenance of the living state. CONCLUSION: Sequential analysis of gene expression is a useful technique for gene expression profiling. As previously indicated by others, a dedicated team can generate useful data within reasonable time limits.