Screening for complement deficiency in bacterial meningitis

Seventy-seven children with bacterial meningitis were screened for complement deficiency. Both the classical and the alternate pathways were normal in 75 patients. Transiently reduced total haemolytic activity of the classical pathway was documented in a boy with meningococcal meningitis. Total haemolytic activity of both the classical and the alternate pathways were reduced in another patient with pneumococcal meningitis: individual complement components determination indicated predominant activation of the alternate pathway.     

Identification of differentially expressed genes in aflatoxin B1- treated cultured primary rat hepatocytes and Fischer 344 rats

Aflatoxin B1 (AFB1), a mutagen and hepatocarcinogen in rats and humans, is a contaminant of the human food supply, particularly in parts of Africa and Asia. AFB1-induced changes in gene expression may play a part in the development of the toxic, immunosuppressive and carcinogenic properties of this fungal metabolite. An understanding of the-role of AFB1 in modulating gene regulation should provide insight regarding mechanisms of AFB1-induced carcinogenesis. We used three PCR- based subtractive techniques to identify AFB1-responsive genes in cultured primary rat hepatocyte RNA: differential display PCR (DD-PCR), representational difference analysis (RDA) and suppression subtractive hybridization (SSH). Each of the three techniques identified AFB1- responsive genes, although no individual cDNA was isolated by more than one technique. Nine cDNAs isolated using DD-PCR, RDA or SSH were found to represent eight genes that are differentially expressed as a result of AFB1 exposure. Genes whose mRNA levels were increased in cultured primary rat hepatocytes after AFB1 treatment were corticosteroid binding globulin (CBG), cytochrome P450 4F1 (CYP4F1), alpha-2 microglobulin, C4b-binding protein (C4BP), serum amyloid A-2 and glutathione S-transferase Yb2 (GST). Transferrin and a small CYP3A-like cDNA had reduced mRNA levels after AFB1 exposure. Full-length CYP3A mRNA levels were increased. When liver RNA from AFB1-treated male F344 rats was evaluated for transferrin, CBG, GST, CYP3A and CYP4F1 expression, a decrease in transferrin mRNA and an increase in CBG, GST, CYP3A and CYP4F1 mRNA levels was also seen. Analysis of the potential function of these genes in maintaining cellular homeostasis suggests that their differential expression could contribute to the toxicity associated with AFB1 exposure.      

Disruption of the gene encoding SF-1 alters the distribution of hypothalamic neuronal phenotypes

The ventromedial nucleus of the hypothalamus (VMH) in mice first emerges as a histologically distinct cell cluster around embryonic day 17 (E17). The earliest known marker for cells destined to form the VMH is the orphan nuclear receptor, steroidogenic factor 1 (SF-1), which can be detected in the hypothalamic primordium by E11. Strikingly, the VMH is absent in newborn SF-1 knockout mice, suggesting that SF-1 is essential for the development of VMH neurons. We reported previously that the VMH can be identified before it emerges as a histologically distinct nucleus (i.e., at E13) by the exclusion of cells that are immunoreactive for both gamma-aminobutyric acid (GABA) and the synthetic enzyme, glutamic acid decarboxylase (GAD67). Subsequently, by E15, the developing VMH is demarcated further by cells that are immunoreactive for neuropeptide Y, estrogen receptor alpha (ERalpha), and galanin. It is noteworthy that the normal exclusion of GABA from the developing VMH is not seen in SF-1 knockout mice, and cells that are immunoreactive for neuropeptide Y, ERalpha, and galanin also are distributed aberrantly in this region. Thus, the absence of SF-1 profoundly affects the cellular architecture of the VMH from early stages in its formation. These data suggest that, directly or indirectly, SF-1 plays important roles in determining the distribution of cells in the mediobasal hypothalamus.     

Parent and physician perspectives on quality of care at the end of life in children with cancer.

PURPOSE: To ascertain parents' and physicians' assessments of quality of end-of-life care for children with cancer and to determine factors associated with high-quality care as perceived by parents and physicians. METHODS: A survey was conducted between 1997 and 2001 of 144 parents of children who received treatment at the Dana-Farber Cancer Institute and Children's Hospital (Boston, MA) or Children's Hospitals and Clinics of St Paul and Minneapolis, MN, between 1990 and 1999 (65% of those located and eligible) and 52 pediatric oncologists. RESULTS: In multivariable models, higher parent ratings of physician care were associated with physicians giving clear information about what to expect in the end-of-life period (odds ratio [OR] = 19.90, P = .02), communicating with care and sensitivity (OR = 7.67, P < .01), communicating directly with the child when appropriate (OR = 11.18, P < .01), and preparing the parent for circumstances surrounding the child's death (OR = 4.84, P = .03). Parent reports of the child's pain and suffering were not significant correlates of parental ratings of care (P = .93 and .35, respectively). Oncologists' ratings of care were inversely associated with the parent's report of the child's experience of pain (OR = 0.15, P = .01) and more than 10 hospital days in the last month of life (OR = 0.24, P < .01). Parent-rated communication factors were not correlates of oncologist-rated care. No association was found between parent and physician care ratings (P = .88). CONCLUSION: For parents of children who die of cancer, doctor-patient communication is the principal determinant of high-quality physician care. In contrast, physicians' care ratings depend on biomedical rather than relational aspects of care.     

The selective serotonin-2A receptor antagonist M100907 reverses behavioral deficits in dopamine transporter knockout mice.

A hyperdopaminergic state in humans has been hypothesized to contribute to the pathology of a number of psychiatric illnesses, including schizophrenia, bipolar disorder, and attention deficit hyperactivity disorder. Mice that display elevated synaptic levels of dopamine due to a genetically engineered deletion of the dopamine transporter (DAT) model behavioral deficits that simulate the above conditions. As novel treatment strategies for these disorders have focused on the serotonin (5-HT) 2A receptor, we determined the capacity of the highly selective 5-HT(2A) receptor antagonist M100907 to reverse behavioral deficits in DAT knockout (KO) mice. Prior to drug treatment, DAT KO mice exhibited increased levels of locomotor activity and highly linearized movement in a novel environment, as well as reduced prepulse inhibition (PPI) of acoustic startle, compared to wild-type littermates. Treatment with M100907 (0.3-1.0 mg/kg, but not 0.1 mg/kg) reversed locomotor deficits in DAT KO mice. Similarly, treatment with 1.0 mg/kg M100907 reversed the PPI deficits in DAT KO mice. These data indicate that selective 5-HT(2A) receptor antagonists, such as M100907, may represent a class of drugs that can be used to treat conditions in which a chronic, elevated dopaminergic tone is present and contributes to abnormal behavior and sensorimotor gating deficits.     

Epigenetic reprogramming of the male genome during gametogenesis and in the zygote

During post-meiotic maturation, male germ cells undergo a formidable reorganization and condensation of their genome. During this phase most histones are globally acetylated and then replaced by sperm-specific basic proteins, named protamines, which compact the genome into a very specific structure within the sperm nucleus. Several studies suggest that this sperm-specific genome packaging structure conveys an important epigenetic message to the embryo. This paper reviews what is known about this fundamental, yet poorly understood, process, which involves not only global changes of the structure of the haploid genome, but also localized specific modifications of particular genomic regions, including pericentric heterochromatin and sex chromosomes. After fertilization, the male genome undergoes a drastic decondensation, and rapidly incorporates new histones. However, it remains different from the maternal genome, bearing specific epigenetic marks, especially in the pericentric heterochromatin region. The functional implications of male post-meiotic and post-fertilization genome reprogramming are not well known, but there is experimental evidence to show that it affects early embryonic development.     

Effects of an adapted leisure education program as a means of support for caregivers of people with dementia

The loss of autonomy associated with dementia affects the people with dementia themselves as well as their caregivers who are often left feeling powerless and incompetent in their caregiving role. Most of the programs developed to support caregivers focus on burden and do not consider the positive aspects of caregiving. Leisure represents a way to enhance the presence of positive aspects in the caring experience. Moreover, leisure might contribute to the maintenance of satisfactory relationships between the caregivers and the person with dementia. An adapted leisure education program was developed as a means of support to caregiver involvement. This study (n = 49) aims to evaluate the impact of this program on caregivers’ well-being, self-efficacy towards adapted leisure, and quality of the relationship with the care receiver. Mixed methods were used. Pretest-posttest with a follow-up design made up the quantitative part. In addition, open-end interviews (n = 10) were conducted. The quantitative results showed few impacts of the program on caregivers. However, the qualitative analysis revealed that the intervention had positive impacts for the caregivers, care receivers and other family members. This study introduces caregiver support in a new, positive perspective by focusing on the positive aspects of caregiving rather than the burden.