Unintentional injury during foreign travel: a review

Unintentional injury is a global public health problem. In 1990, an estimated 5 million people worldwide died as a result of an injury or poisoning. This accounted for 10% of deaths from all causes that year, and over half of the estimated 900 million years of life lost in 1990 due to premature death. Although mortality rates for ischemic heart disease, cerebrovascular disease, and cancer are higher, the majority of people dying of these causes are elderly, with far fewer potential years of life to live. Reasons for the increasing public health importance of injury include the decline of infectious disease, the processes of urbanization, industrialization, motorization, and increased opportunities to travel.     

Recombinant P-selectin glycoprotein ligand-1 directly inhibits leukocyte rolling by all 3 selectins in vivo: complete inhibition of rolling is not required for anti-inflammatory effect

Selectin-dependent leukocyte rolling is one of the earliest steps of an acute inflammatory response and, as such, contributes to many inflammatory diseases. Although inhibiting leukocyte rolling with selectin antagonists is a strategy that promises far-reaching clinical benefit, the perceived value of this strategy has been limited by studies using inactive, weak, or poorly characterized antagonists. Recombinant P-selectin glycoprotein ligand-1-immunoglobulin (rPSGL-Ig) is a recombinant form of the best-characterized selectin ligand (PSGL-1) fused to IgG, and is one of the best prospects in the search for effective selectin antagonists. We have used intravital microscopy to investigate the ability of rPSGL-Ig to influence leukocyte rolling in living blood vessels and find that it can reduce rolling dependent on each of the selectins in vivo. Interestingly, doses of rPSGL-Ig required to reverse pre-existing leukocyte rolling are 30-fold higher than those required to limit inflammation, suggesting additional properties of this molecule. In support of this, we find that rPSGL-Ig can bind the murine chemokine KC and inhibit neutrophil migration toward this chemoattractant in vitro.     

Relationship of birth cohort and early age at onset of illness in a bipolar disorder case registry

OBJECTIVE: Utilizing data from a previously characterized registry of subjects with bipolar illness, the authors examined age at onset of the first illness episode in cohorts of subjects born from 1900 through 1939 and from 1940 through 1959. METHOD: Demographic and clinical characteristics at the first full episode of bipolar disorder of subjects in a diagnostically validated voluntary bipolar disorder registry (N=1,218) were reviewed and subjected to statistical analyses. RESULTS: The median age at onset of the first episode of bipolar illness was lower by 4.5 years in subjects born during or after 1940 (median age=19 years), compared with subjects born before 1940 (median age=23.5 years). The proportion of subjects with bipolar disorder presenting with a prepubertal onset was significantly higher in the later birth-year cohort than in the earlier birth-year cohort. More than 50% of male and female subjects in both cohorts had a depressive episode as the first episode of bipolar illness. Subjects in each cohort who had a parent with major depression, bipolar disorder, or schizophrenia experienced their first episode nearly 4 to 5 years earlier than the other subjects in the cohort. CONCLUSIONS: Prospective epidemiological studies conducted with bipolar disorder subjects are needed to either affirm or refute these data on age at illness onset. If the results are affirmed, the early recognition of prepubertal bipolar disorder will be important, so that the condition can be treated with appropriate medications and medications that could potentially worsen the illness course can be avoided. Similarly, early recognition of bipolar illness is important, especially in women, to minimize use of antidepressant monotherapy for patients with bipolar illness. Among young people presenting with major depression as the first illness episode, a parental history of major depression, bipolar disorder, or psychosis may be a useful pointer to future bipolar disorder. Early recognition and appropriate treatment of bipolar illness may prevent the development of chronicity and serious functional impairment.     

Tolerance of neonatal rat brain to acute hyperammonemia

The aim of the present work was to study the effects of hyperammonemia on brain energy metabolism in neonatal rats. Rats were rendered hyperammonemic by ammonium acetate administration. This decreased brain ATP concentrations but enhanced brain ammonia and lactate levels in both adult and neonatal rats. In adult rats, the decrease in brain ATP concentrations was accompanied by a plunge in the respiratory control rate (RCR) of brain mitochondria. However, the ammonia-induced effect on RCR was not observed in neonatal rats, suggesting that the fall in ATP levels observed in neonatal rats would not be due to an impairment of mitochondrial respiratory efficiency. However, in neonatal rats the increase in blood and brain ammonia concentrations did not change brain glutamate concentrations but decreased glutamine contents. These results may be of relevance for the understanding of the resistance of neonatal rats observed in this work to acute ammonia toxicity     

Environmental enrichment exacerbates amyloid plaque formation in a transgenic mouse model of Alzheimer disease

Epidemiological studies of Alzheimer patients from a wide variety of ethnic and socioeconomic backgrounds have identified education and occupation as environmental factors that can affect the risk of developing disease. A model of environmental manipulation in rodents uses enriched housing to provide cognitive and social stimulation. Previous studies have established elevations in synaptic number and function in rodents housed under enriched conditions. Recent experiments in hippocampal cultures have demonstrated that synaptic activity can influence the processing of amyloid precursor protein (APP). Here we examined whether changes in synaptic activity brought about by enriched housing might also influence the deposition of amyloid plaques in vivo using a transgenic mouse model of Alzheimer disease (AD). Mice co-expressing mutant APP and presenilin 1 (PS1) were housed in either enriched or standard cages from 2 months of age and then killed for pathological evaluation several months later. We find that, as compared to littermates housed in standard cages, the enriched APP/PS1 transgenic mice develop a higher amyloid burden with commensurate increases in aggregated and total A beta. These results suggest that A beta deposition can be exacerbated by the neuronal changes associated with enrichment, and demonstrate a substantial, albeit paradoxical, environmental influence on the progression of pathology in a mouse model of AD.     

Hematopoietic growth factors in myelodysplastic syndromes

The myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized clinically by refractory cytopenias in one or more myeloid cell lines and an increased probability of transformation to acute leukemia. Supportive care remains the mainstay of therapy in MDS and frequently includes monotherapy and combination therapy with hematopoietic growth factors, such as erythropoietin, granulocyte colony-stimulating factor, and granulocyte macrophage colony-stimulating factor. Clinical trials have demonstrated the ability of growth factors to improve neutropenia and anemia in selected patients with MDS, which may have clinical, quality-of-life, and economic benefits for patients even though overall survival has not been improved. This paper reviews the role of hematopoietic growth factors in the treatment of MDS.