Preliminary trials on the effects of weaning and larval diets on survival and growth of silver therapon (Leiopotherapon plumbeus) larvae

Abstract only.Success in larval rearing of silver therapon can be achieved through early weaning of fish larvae from live food to artificial diet. Two experiments were carried out to investigate the effects of (a) weaning age (abrupt and gradual) and (b) larval diets (artificial and live foods) on survival and growth of silver therapon (Leiopotherapon plumbeus). In the first experiment, larvae were randomly stocked in round 4-l plastic basins at 15 larvae per basin to provide triplicates of four weaning age treatments (8, 14, 20 and 26 days after hatching or DAH, respectively). Larvae were fed thrice daily for 21 days with commercial feed (CF) and with copepods (COP) which served as the control. Larvae weaned at 26 DAH had the highest survival, body weight and total length among the treatment groups, which were comparable with that of the control. In the co-feeding protocol, larvae were fed Artemia nauplii (ART) as the control group and co-fed with either zooplankton i.e. 50% COP + 50% CF or 50% ART + 50% CF for 8 (8-15 DAH), 6 (14-19 DAH) and 4 (20-23 DAH) days, and suddenly weaned to FM until 21 days. Survival ranged from 22.2 ± 16.8 to 40.0 ± 24.0% between treatments, but was still lower than the control (88.9 ± 3.8%). Body weight and total length were significantly higher in larvae with co-feeding for 4 days (70.1 ± 2.8 mg; 18.1 ± 0.8 mm), but were still lower than that of the control (142.8 ± 7.6 mg; 22.3 ± 0.3 mm). In the second experiment, 26-day old larvae were stocked in 20-l glass aquaria at 4 larvae l-1. Larval diets ((I) commercial prawn feed (38% crude protein); (II) Artemia nauplii; (III) copepods; and (IV) free-living nematode Panagrellus redivivus) were given twice daily for 28 days. Survival was highest in larvae fed Artemia nauplii and poor in copepod fed larvae. Final total length (TL) of larvae fed prawn diet was higher than those fed copepod or nematodes. However, best growth was noted in larvae fed Artemia nauplii (TL= 24.30 ± 0.81 mm; BW = 156 ± 8 mg; specific growth rate or SGR = 5.33 ± 0.19%/d)

Larval rearing of silver therapon (Leiopotherapon plumbeus) in outdoor tanks

Abstract only.Silver therapon (Leiopotherapon plumbeus, Kner 1864), locally known as ayungin, is an important freshwater food fish species found in Laguna de Bay, the largest lake in the Philippines. Its market price is twice that of other most sought after freshwater fishes such as tilapia and milkfish. However, intense fishing pressure on the species has significantly reduced the wild stock in Laguna de Bay. Studies to develop hatchery techniques for this indigenous freshwater fish species are therefore needed to produce seedstock for possible culture and wild stock rehabilitation. This study highlights the successful larval rearing of silver therapon in outdoor concrete tanks. Larvae reared in outdoor tanks with natural food (grown two weeks beforehand) reached the juvenile stage (40 days after hatching (DAH)), suggesting the presence of some suitable live food organisms in pre-conditioned rearing water. However, larval survival rates were low (11.58 ± 6.56% at stocking density of 0.9 larvae l-1), which is probably linked to the density of food items, particularly during the onset of exogenous feeding or due to high stocking density of larvae. To improve the availability of natural food for the larvae, fertilization of the rearing water in the outdoor tanks stocked with larvae at two densities (0.4 and 0.6 larvae l-1) was performed. Larval growth and survival were improved at stocking density of 0.4 larvae l-1 than at 0.6 larvae l-1. Diet composition of first-feeding silver therapon larvae in outdoor tanks inoculated with cultured microalgae (Chorella sorokiniana) and zooplankton was also determined. Larvae were able to consume rotifers and some phytoplankton beginning at 2 DAH and larger preys such as cladocerans and insect larvae starting at 12 DAH. The efficacy of raising silver therapon larvae in outdoor tanks using ambient lake water was also evaluated. Larvae reared in ambient lake water grew well but survival (48.44 ± 7.85%) was significantly improved in treatments where tropical almond or talisay Terminalia catappa leaves were added during the first two weeks of larval rearing

Heterologous influenza vRNA segments with identical non-coding sequences stimulate viral RNA replication in trans

The initiation of transcription and replication of influenza A virus requires the 5' and 3' ends of vRNA. Here, the role of segment-specific non-coding sequences of influenza A virus on viral RNA synthesis was studied. Recombinant viruses, with the nonstructural protein (NS) segment-specific non-coding sequences replaced by the corresponding sequences of the neuraminidase (NA) segment, were characterized. The NS and NA vRNA levels in cells infected with these mutants were much higher than those of the wild type, whereas the NS and NA mRNA levels of the mutants were comparable to the wild-type levels. By contrast, the PB2 vRNA and mRNA levels of all the tested viruses were similar, indicating that vRNA with heterologous segment-specific non-coding sequences was not affected by the mutations. The observations suggested that, with the cooperation between the homologous 5' and 3'segment-specific sequences, the introduced mutations could specifically enhance the replication of NA and NS vRNA

Subclinical thyroid dysfunction and cognitive decline in old age

<p>Background: Subclinical thyroid dysfunction has been implicated as a risk factor for cognitive decline in old age, but results are inconsistent. We investigated the association between subclinical thyroid dysfunction and cognitive decline in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER).</p> <p>Methods: Prospective longitudinal study of men and women aged 70–82 years with pre-existing vascular disease or more than one risk factor to develop this condition (N = 5,154). Participants taking antithyroid medications, thyroid hormone supplementation and/or amiodarone were excluded. Thyroid function was measured at baseline: subclinical hyper- and hypothyroidism were defined as thyroid stimulating hormones (TSH) <0.45 mU/L or >4.50 mU/L respectively, with normal levels of free thyroxine (FT4). Cognitive performance was tested at baseline and at four subsequent time points during a mean follow-up of 3 years, using five neuropsychological performance tests.</p> <p>Results: Subclinical hyperthyroidism and hypothyroidism were found in 65 and 161 participants, respectively. We found no consistent association of subclinical hyper- or hypothyroidism with altered cognitive performance compared to euthyroid participants on the individual cognitive tests. Similarly, there was no association with rate of cognitive decline during follow-up.</p> <p>Conclusion: We found no consistent evidence that subclinical hyper- or hypothyroidism contribute to cognitive impairment or decline in old age. Although our data are not in support of treatment of subclinical thyroid dysfunction to prevent cognitive dysfunction in later life, only large randomized controlled trials can provide definitive evidence.</p&gt

Subclinical thyroid dysfunction and cognitive decline in old age

<p>Background: Subclinical thyroid dysfunction has been implicated as a risk factor for cognitive decline in old age, but results are inconsistent. We investigated the association between subclinical thyroid dysfunction and cognitive decline in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER).</p> <p>Methods: Prospective longitudinal study of men and women aged 70–82 years with pre-existing vascular disease or more than one risk factor to develop this condition (N = 5,154). Participants taking antithyroid medications, thyroid hormone supplementation and/or amiodarone were excluded. Thyroid function was measured at baseline: subclinical hyper- and hypothyroidism were defined as thyroid stimulating hormones (TSH) <0.45 mU/L or >4.50 mU/L respectively, with normal levels of free thyroxine (FT4). Cognitive performance was tested at baseline and at four subsequent time points during a mean follow-up of 3 years, using five neuropsychological performance tests.</p> <p>Results: Subclinical hyperthyroidism and hypothyroidism were found in 65 and 161 participants, respectively. We found no consistent association of subclinical hyper- or hypothyroidism with altered cognitive performance compared to euthyroid participants on the individual cognitive tests. Similarly, there was no association with rate of cognitive decline during follow-up.</p> <p>Conclusion: We found no consistent evidence that subclinical hyper- or hypothyroidism contribute to cognitive impairment or decline in old age. Although our data are not in support of treatment of subclinical thyroid dysfunction to prevent cognitive dysfunction in later life, only large randomized controlled trials can provide definitive evidence.</p&gt

Multi-parallel qPCR provides increased sensitivity and diagnostic breadth for gastrointestinal parasites of humans: field-based inferences on the impact of mass deworming

BACKGROUND: Although chronic morbidity in humans from soil transmitted helminth (STH) infections can be reduced by anthelmintic treatment, inconsistent diagnostic tools make it difficult to reliably measure the impact of deworming programs and often miss light helminth infections. METHODS: Cryopreserved stool samples from 796 people (aged 2-81 years) in four villages in Bungoma County, western Kenya, were assessed using multi-parallel qPCR for 8 parasites and compared to point-of-contact assessments of the same stools by the 2-stool 2-slide Kato-Katz (KK) method. All subjects were treated with albendazole and all Ascaris lumbricoides expelled post-treatment were collected. Three months later, samples from 633 of these people were re-assessed by both qPCR and KK, re-treated with albendazole and the expelled worms collected. RESULTS: Baseline prevalence by qPCR (n = 796) was 17 % for A. lumbricoides, 18 % for Necator americanus, 41 % for Giardia lamblia and 15% for Entamoeba histolytica. The prevalence was <1% for Trichuris trichiura, Ancylostoma duodenale, Strongyloides stercoralis and Cryptosporidium parvum. The sensitivity of qPCR was 98% for A. lumbricoides and N. americanus, whereas KK sensitivity was 70% and 32%, respectively. Furthermore, qPCR detected infections with T. trichiura and S. stercoralis that were missed by KK, and infections with G. lamblia and E. histolytica that cannot be detected by KK. Infection intensities measured by qPCR and by KK were correlated for A. lumbricoides (r = 0.83, p < 0.0001) and N. americanus (r = 0.55, p < 0.0001). The number of A. lumbricoides worms expelled was correlated (p < 0.0001) with both the KK (r = 0.63) and qPCR intensity measurements (r = 0.60). CONCLUSIONS: KK may be an inadequate tool for stool-based surveillance in areas where hookworm or Strongyloides are common or where intensity of helminth infection is low after repeated rounds of chemotherapy. Because deworming programs need to distinguish between populations where parasitic infection is controlled and those where further treatment is required, multi-parallel qPCR (or similar high throughput molecular diagnostics) may provide new and important diagnostic information

Synthesis and Evaluation of 99mTc-Labelled Monoclonal Antibody 1D09C3 for Molecular Imaging of Major Histocompatibility Complex Class II Protein Expression

Purpose: It is known that major histocompatibility complex class II protein HLA-DR is highly expressed in B-cell lymphomas and in a variety of autoimmune and inflammatory diseases. Therefore, a radiolabelled fully humanized IgG4 monoclonal antibody (mAb) can provide useful prognostic and diagnostic information. Aims of the present study were to radiolabel an anti-HLA-DR mAb with technetium-99m and to evaluate its binding specificity, tissue distribution and targeting potential. Procedures: For labelling, we compared a direct method, after 2-mercaptoethanol (2-ME) reduction of disulphide bonds, with a two-step labelling method, using a heterobifunctional succinimidyl-6-hydrazinonicotinate hydrochloride chelator. Several in vitro quality controls and in vivo experiments in mice were performed. Results: We obtained highest labelling efficiency (LE, 998%) and specific activity (SA; 5,550 MBq/mg) via the direct method. In vitro quality control showed good stability, structural integrity and retention of the binding properties of the labelled mAb. The biodistribution in mice showed high and persistent uptake in spleen and suggests kidney and liver-mediated clearanc

Human Herpesvirus 8 Seropositivity Among Sexually Active Adults in Uganda

Sexual transmission of human herpesvirus 8 (HHV8) has been implicated among homosexual men, but the evidence for sexual transmission among heterosexual individuals is controversial. We investigated the role of sexual transmission of HHV8 in a nationally representative sample in Uganda, where HHV8 infection is endemic and transmitted mostly during childhood.The study population was a subset of participants (n = 2681) from a population-based HIV/AIDS serobehavioral survey of adults aged 15-59 years conducted in 2004/2005. High risk for sexual transmission was assessed by questionnaire and serological testing for HIV and herpes simplex virus 2. Anti-HHV8 antibodies were measured using two enzyme immunoassays targeting synthetic peptides from the K8.1 and orf65 viral genes. The current study was restricted to 2288 sexually active adults. ORs and 95% CIs for HHV8 seropositivity were estimated by fitting logistic regression models with a random intercept using MPLUS and SAS software.The weighted prevalence of HHV8 seropositivity was 56.2%, based on 1302 seropositive individuals, and it increased significantly with age (P(trend)<0.0001). In analyses adjusting for age, sex, geography, education, and HIV status, HHV8 seropositivity was positively associated with reporting two versus one marital union (OR:1.52, 95% CI: 1.17-1.97) and each unit increase in the number of children born (OR: 1.04, 95% CI: 1.00-1.08), and was inversely associated with ever having used a condom (OR: 0.64, 95% CI: 0.45-0.89). HHV8 seropositivity was not associated with HIV (P = 0.660) or with herpes simplex virus 2 (P = 0.732) seropositivity. Other sexual variables, including lifetime number of sexual partners or having had at least one sexually transmitted disease, and socioeconomic variables were unrelated to HHV8 seropositivity.Our findings are compatible with the conclusion that sexual transmission of HHV8 in Uganda, if it occurs, is weak