Immunogenicity of an inactivated novel goose parvovirus vaccine for short beak and dwarfism syndrome in Cherry Valley ducks.

Duck short beak and dwarfism syndrome (SBDS) is a viral infectious disease caused by novel goose parvovirus (NGPV), which has been responsible for serious economic losses to the Chinese duck industry in recent years. Currently, there is no effective vaccine against this disease. In this study, we developed an inactivated virus vaccine candidate for SBDS based on NGPV strain DS15 isolated from a duck in China. Immune efficacy was evaluated in 112 ducks, which were randomly divided into vaccination, challenge-control, vaccination-challenge, and blank control groups (28 per group). Clinical characteristics, antibodies, virus excretion, viremia, and pathological changes were monitored. No morbidity or death was observed in the immunized ducks, which showed normal weight and a good mental state. High levels of serum antibodies (optical density at 450 nm of ~ 0.63) were detected in ducks immunized with the inactivated vaccine at 7 days post-vaccination (dpv), and the titer of virus-neutralizing antibodies increased from 1:23 to 1:28.5 from 7 to 42 dpv. Measurement of the viral load in anal swab, serum, and tissue samples showed that vaccination significantly inhibited the replication of NGPV in immunized ducks. Moreover, NGPV could not be isolated from the spleens of immunized or vaccinated and challenged ducks. Collectively, these results demonstrate that the newly developed inactivated NGPV vaccine, administered in an oil emulsion adjuvant, possesses good immunogenicity and represents a potentially powerful tool for SBDS prevention and control.

Thyroid hormone is essential for pituitary somatotropes and lactotropes.

Mice homozygous for a disruption in the alpha-subunit essential for TSH, LH, and FSH activity (alphaGsu-/-) exhibit hypothyroidism and hypogonadism similar to that observed in TSH receptor-deficient hypothyroid mice (hyt) and GnRH-deficient hypogonadal mutants (hpg). Although the five major hormone-producing cells of the anterior pituitary are present in alphaGsu-/- mice, the relative proportions of each cell type are altered dramatically. Thyrotropes exhibit hypertrophy and hyperplasia, and somatotropes and lactotropes are underrepresented. The size and number of gonadotropes in alphaGsu mutants are not remarkable in contrast to the hypertrophy characteristic of gonadectomized animals. The reduction in lactotropes is more severe in alphaGsu mutants (13-fold relative to wild-type) than in hyt or hpg mutants (4.5- and 1.5-fold, respectively). In addition, T4 replacement therapy of alphaGsu mutants restores lactotropes to near-normal levels, illustrating the importance of T4, but not alpha-subunit, for lactotrope proliferation and function. T4 replacement is permissive for gonadotrope hypertrophy in alphaGsu mutants, consistent with the role for T4 in the function of gonadotropes. This study reveals the importance of thyroid hormone in developing the appropriate proportions of anterior pituitary cell types.

Short stature at school entry--an index of social deprivation? (The Wessex Growth Study).

This study was carried out to examine the biological and environmental variables associated with non-organic short stature. We observed an unselected population of very short normal children (SN) and their age- and sex-matched controls (C) within the community. All 14,346 children in two health districts entering school during 2 consecutive years were screened for short stature, and those whose height lay below the 3rd centile, according to Tanner and Whitehouse standards (n = 180) were identified. Excluding 32 with pathology, five from ethnic minorities and three who refused to take part, the remaining SN children (mean height SDS-2.26) were matched with 140 age- and sex-matched controls (C) of average height (mean height SDs 0.14). Birth weight, target height and predicted adult height (based on parental height and bone age respectively), medical and social background (obtained from parental interviews), and school performance (assessed by class teachers) were the main outcome measures. Mean birth weight of the SN children was significantly lower than C (SN = 2845 g, C = 3337 g, P < 0.001). Mean mid-parental target height was also very different (SN = 162.0 cm, C = 170.9 cm, P < 0.001). Thirty-five per cent of SN children (C = 6%) had height SD scores below parental target range, though only 10% had predicted heights below target range (mean delay in bone age 0.68 years). There was a significant difference between SN children and C in the number of children in the household (SN = 2.8, C = 2.4 (P = 0.007) and in socio-economic status (P < 0.002). Many more SN children were in social classes IV and V (SN = 31%, C = 13%, P < 0.002), and had an unemployed father (SN = 22%, C = 10%, P < 0.010), highlighting the importance of environmental influences on growth. One in four SN children was judged to have serious psychosocial problems. However, the lower the socio-economic class, the less likely the SN children were to be inappropriately short for parents. Significantly more SN children were reported to have asthma (SN = 18%, C = 7%, P < 0.007) and eczema (SN = 19%, C = 5%, P < 0.001), though only the latter was significantly associated with stature below target height for both SN and C groups. Biological variables are often insufficient to explain short stature. No child, whatever the parental height, should be dismissed as normal without careful evaluation, as poor growth in the early years may be an important pointer to an adverse but potentially remediable environment.

Medical management and complications of X-linked hypophosphatemic vitamin D resistant rickets.

To improve the growth failure, bowed legs, and biochemical and radiological abnormalities in patients with X-linked hypophosphatemic vitamin D resistant rickets (XLH), combined therapy of phosphate and calcitriol is the best therapeutic approach at present. However, the complications involving combined therapy, such as hypercalcemia, nephrocalcinosis and hyperparathyroidism, are not fully solved. To achieve better control, new therapeutic approaches have been reported recently, for example, growth hormone (GH) or new vitamin D analogs. GH improved linear growth, decreased phosphate reabsorption and increased 1-alpha-hydroxylase activity. Furthermore, 24R,25-dihydroxyvitamin D3 (24,25) improved the bone lesions in hypophosphatemic (Hyp) mice, and also in XLH, without the adverse effects such as hypercalcemia or hypercalciuria compared with 1,25-dihydroxyvitamin D3. These new approaches should be considered for the treatment of patients with XLH.

Comparison of school nurse and auxologist height velocity measurements in school children with short stature. (The Hackney Growth Initiative).

To examine the possible use of height velocity (HV) as a growth screening tool, annual HV data calculated from height measurements made by school nurses were compared with those based on an auxologist's measurements in 20 short school children. The subjects were 12 primary school children (seven girls, five boys) with a mean (+/- SD) age of 5.9(0.6) years and eight secondary school children (six girls, two boys) with a mean (+/- SD) age of 11.8 (0.4) years. Heights were measured by the school nurses, separated by an interval of 1 year. Mean HV of the primary school children when assessed by school nurses was 5.92 cm/year compared with 5.97 cm/year when assessed by the auxologist. Mean (+/- SD) HV standard deviation score (HVSDS) was 0.03 (0.97) and 0.10 (1.15) respectively. Mean HV of the secondary school children when assessed by school nurses was 6.04 cm/year compared with 5.63 cm/year when assessed by the auxologist. Mean (+/- SD) HVSDS was -0.8 (2.1) and -1.21 (1.54) respectively. Of eight children (three primary, five secondary) identified by the auxologist as having HV < 25th centile of Tanner and Whitehouse standards only four were identified by school nurses (one primary, three secondary). One child identified by school nurses to have HV < 25th centile was found by the auxologist to be above the 25th centile. We conclude that HV assessment may fail to identify significant pathology in the community and that accurate height measurement rather than HV should be the principal referral criterion.