Rapid destruction of newly synthesized excess beta-globin chains in HbH disease

A subject with HbG Philadelphia-HbH disease exhibited an unusually high alpha/beta synthesis ratio; when peripheral blood was tested in vitro on several occasions, ratios of 0.63 - 0.89 were obtained after incubations of 30-120 min. HbH amounted to 5%-8% of the circulating hemoglobin. Rapid destruction of excess newly synthesized beta-globin was demonstrated in kinetic and pulse-chase experiments. After 2 min of incubation, the alpha/beta synthesis ratio was 0.48; this figure rose to 0.89 by 30 min. The zero time alpha/beta ratio was estimated to be 0.35. The degradation of beta-chains was calculated to proceed at approximately one-half the rate of beta-globin synthesis; this result was confirmed by the loss of 50% of the specific activity in beta- chains during 9 min of a chase experiment following a 10-min radioactive pulse. The results suggest that efficient proteolysis may be responsible, in some blacks, for the low levels of excess beta- globin chains in HbH disease as well as for the mildness of the clinical disorder.     

The role of calcium in lymphocyte proliferation. (An interpretive review)

A small quantity of extracellular calcium is required for the stimulation of lymphocytes by mitogens such as plant lectins. Lectin binding to the lymphocyte surface and early postbinding events that eventually lead to DNA synthesis are calcium dependent. Mitogenic lectins such as PHA and Con-A rapidly increase the size of an exchangeable pool of cell calcium and cause a smaller rise in intracellular ionized calcium. The increase in ionized calcium is so small (100-200 nM), however, that no increase in total cell calcium is measurable. When lymphocytes are stimulated by a lectin, the rate of calcium entry into the cell increases, but the plasma membrane calcium extrusion pump can prevent the total cell calcium from increasing measurably. The calcium ionophore A23187 is a lymphocyte mitogen and causes an increase in the exchangeable, ionized, and total cell calcium. The former two effects may be causal in mitogenesis; the latter effect is cytotoxic. With A23187 treatment, the rate of calcium influx exceeds the maximum rate of the plasma membrane extrusion pump and cell calcium increases in proportion to the concentration of A23187. The mitochondria, by virtue of their high membrane potential, provide a sink for the buffering of cytoplasmic calcium after A23187 treatment. Thus, the plasma membrane or mitochondria regulate the distribution of lymphocyte calcium when the cell is stimulated by mitogenic lectins or ionophores. The evidence strongly suggests that an alteration in calcium pools or an increase in cytoplasmic ionized calcium plays a role in the initiation of the biochemical reactions that lead to mitogen-induced lymphocyte proliferation in vitro and, perhaps, to the immune response.     

Temperament in the developmental course: a longitudinal comparison of New York Longitudinal Study-derived dimensions with the Junior Temperament and Character Inventory

OBJECTIVE: Despite theoretical discrepancies between different concepts of temperament, some core dimensions are thought to be common to the various models. We compared temperamental traits derived from the New York Longitudinal Study (NYLS) model and the Cloninger dimensions in the developmental course and investigated the associations of temperament with sex as well as with obstetric risks or psychosocial risks present at birth. METHODS: Participants were 151 boys and 157 girls born at differing degrees of obstetric and psychosocial risk from a longitudinal study on a high-risk community sample. In infancy and childhood, NYLS-derived temperamental characteristics were assessed by a highly structured parent interview and standardized behavioral observations. At age 15 years, the Junior Temperament and Character Inventory/12-18 was administered. RESULTS: Moderate correlations were found between Junior Temperament and Character Inventory scales in adolescence and NYLS-derived factors in childhood. The psychosocial risk load seemed to influence the expression of novelty seeking or corresponding NYLS-derived factors, whereas the obstetric risks did not contribute to variation in temperament. Our findings further support highly sex-specific gene x environment interactions on temperament in the developmental course. CONCLUSION: The content of our NYLS-derived factors and the specific type of association across different temperament constructs fit into the increasing consensus regarding a small number of higher-order temperamental traits.     

Eyebrow anomalies as a diagnostic sign of genomic disorders

Silengo M, Belligni E, Molinatto C, Baldassare G, Biamino E, Chiesa N, Zuffardi O, Girirajan S, Eichler EE, Ferrero GB. Eyebrow anomalies as a diagnostic sign of genomic disorders. Microdeletions and microduplications in the human genome, termed genomic disorders, contribute to a high proportion of human multisystemic neurodevelopmental diseases and are detected by array‐based comparative genomic hybridization (aCGH). In general, most genomic disorders are associated with craniofacial and skeletal features and behavioural abnormalities, in addition to learning disability and developmental delay (LD/DD). Specifically, recognition of a characteristic ‘acial gestalt’ has been the key to distinguish one genomic disorder from the other. Here, we report our experience concerning the relevance of abnormal eyebrow pattern as a diagnostic indicator of specific genomic disorders.     

LEARN 2 MOVE 0-2 years: effects of a new intervention program in infants at very high risk for cerebral palsy; a randomized controlled trial

Background

Bronchiolitis is the most common reason for admission of infants to hospital in developed countries. Fluid replacement therapy is required in about 30% of children admitted with bronchiolitis. There are currently two techniques of fluid replacement therapy that are used with the same frequency-intravenous (IV) or nasogastric (NG). The evidence to determine the optimum route of hydration therapy for infants with bronchiolitis is inadequate. This randomised trial will be the first to provide good quality evidence of whether nasogastric rehydration (NGR) offers benefits over intravenous rehydration (IVR) using the clinically relevant continuous outcome measure of duration of hospital admission.

Methods/Design

A prospective randomised multi-centre trial in Australia and New Zealand where children between 2 and 12 months of age with bronchiolitis, needing non oral fluid replacement, are randomised to receive either intravenous (IV) or nasogastric (NG) rehydration. 750 patients admitted to participating hospitals will be recruited, and will be followed daily during the admission and by telephone 1 week after discharge. Patients with chronic respiratory, cardiac, or neurological disease; choanal atresia; needing IV fluid resuscitation; needing an IV for other reasons, and those requiring CPAP or ventilation are excluded. The primary endpoint is duration of hospital admission. Secondary outcomes are complications, need for ICU admission, parental satisfaction, and an economic evaluation. Results will be analysed using t-test for continuous data, and chi squared for categorical data. Non parametric data will be log transformed.

Discussion

This trial will define the role of NGR and IVR in bronchiolitis

Trail registration

The trial is registered with the Australian and New Zealand Clinical Trials Registry - ACTRN12605000033640     

Critical phenomena and thermodynamics of dilute aqueous sodium chloride to 823 K

Semiempirical equations are developed that represent the behavior of dilute solutions of NaCl in water (steam) in the range 723-823 K where ion pairing is extensive. This supplements the equations given earlier for more concentrated solutions. In this temperature range the system NaCl/H₂O shows critical behavior with two phases below the critical pressure. The equations for the dilute solutions yield critical behavior. Though the equations for concentrated solutions do not yield critical behavior at the critical pressure, only a very small interpolation function is required to connect smoothly the two equations. The ion-pairing equilibrium constants are reported as well as the Gibbs energies of hydration for both ions and ion pairs.     

<Emphasis Type="Italic">SMN1</Emphasis>dosage analysis in spinal muscular atrophy from India

Background  

Spinal muscular atrophy (SMA) represents the second most common fatal autosomal recessive disorder after cystic fibrosis. Due to the high carrier frequency, the burden of this genetic disorder is very heavy in developing countries like India. As there is no cure or effective treatment, genetic counseling becomes very important in disease management. SMN1 dosage analysis results can be utilized for identifying carriers before offering prenatal diagnosis in the context of genetic counseling.