Drug‐Mediated Gene Regulation of Vitamin D3 Metabolism in Primary Human Dermal Fibroblasts

Vitamin D metabolism was studied in primary human dermal fibroblasts with focus on drug‐mediated gene regulation related to adverse side effects of antiretroviral drugs used in HIV therapy. The fibroblasts expressed mRNA for cytochrome P450 (CYP) enzymes catalysing bioactivating (CYP2R1, CYP27A1 and CYP27B1) and catabolic reactions (CYP24A1). The cells produced both 25‐hydroxyvitamin D₃ and 1α,25‐dihydroxyvitamin D₃. The results demonstrate that primary dermal fibroblasts have an active vitamin D₃‐metabolizing system. High incidence of low bone mineral density is a concern for HIV‐infected patients treated with antiretroviral drugs. Osteomalacia and severe vitamin D deficiency have been reported. We investigated whether drug‐mediated gene regulation could be a possible mechanism behind these adverse drug effects. Fibroblasts were treated with different drugs used in HIV therapy, and the 1α,25‐dihydroxyvitamin D₃ levels and relative mRNA levels for crucial enzymes were determined. Efavirenz, stavudine and ritonavir significantly down‐regulated the bioactivating CYP2R1 and up‐regulated the catabolic CYP24A1. The drugs reduced bioactivating enzyme activities and cellular levels of 1α,25‐dihydroxyvitamin D₃. The current results indicate that effects on gene expression may lead to disturbed vitamin D metabolism and decreased cellular levels of active vitamin D₃. The data are consistent with the impaired bone health in patients treated with certain antiretroviral drugs.     

Delivery success rate of engineered nanoparticles in the presence of the protein corona: a systems-level screening

Nanoparticles (NPs) for medical applications are often introduced into the body via intravenous injections, leading to the formation of a protein corona on their surface due to the interaction with blood plasma proteins. Depending on its composition and time evolution, the corona will modify the biological behavior of the particle. For successful delivery and targeting, it is therefore important to assess on a quantitative basis how and to what extent the presence of the corona perturbs the specific interaction of a designed NP with its cellular target. We present a theoretical systems-level analysis, in which peptides have been covalently coupled to the surface of nanoparticles, describing the delivery success rate in varying conditions, with regard to protein composition of the surrounding fluid. Dynamic modeling and parameter sensitivity analysis proved to be useful and computationally affordable tools to aid in the design of NPs with increased success rate probability in a biological context.From the Clinical EditorThe formation of a protein corona consisting of blood plasma proteins on the surface of intravenously delivered nanoparticles may modify the biological behavior of the particles. This team of investigators present a theoretical systems-level analysis of this important and often neglected phenomenon.     

A multi-disciplinary education process related to the discharging of children from hospital when the child has been diagnosed with type 1 diabetes - a qualitative study

Background  

Worldwide, insulin-dependent type 1 diabetes is one of the most frequently diagnosed long-term endocrine disorders found in children and the incidences of this diseased is still increasing. In Sweden the routines are, according to national guidelines, when the child is diagnosed with type 1 diabetes, the child and its family remains at the hospital for about two weeks. There is limited knowledge about how a diabetes team handles a child and its family from admission to discharge, therefore the purpose of this study was to seek a deeper understanding of how the diabetes team's parent/child education process works, from admission to discharge, among families with a child newly diagnosed with type 1 diabetes.     

Formaldehyde treatment increases the immunogenicity and decreases the toxicity of Haemophilus ducreyi cytolethal distending toxin

Haemophilus ducreyi cytolethal distending toxin (HdCDT) is a tripartite AB toxin, which causes DNA damage in affected cells. We investigated the effects of formaldehyde on the chemical, biological, and immunological properties of the HdCDT complex, which was purified by immobilizing the glutathione S-transferase (GST)-CdtB fusion protein, followed by binding of the CdtA and CdtC recombinant proteins. The HdCDT was treated with increasing concentrations of formaldehyde in the presence of lysine. The treatment of HdCDT at 1 and 0.1 mg protein/ml with 320 and 80 mM of formaldehyde, respectively, resulted in the complete abrogation of cytotoxic activity, loss of DNase activity, and loss of binding capacity to HeLa cells. The toxoid showed protein bands of 75-150 kDa in SDS-PAGE, composed of the three cross-linked CDT components detected by immunoblotting. Three doses of 10 microg protein/mouse of the formaldehyde-treated HdCDT elicited toxin-neutralizing antibodies at titers about 200 times higher than those elicited by the native toxin. The described methodology may be applied to produce immunogenic toxoids from other CDTs, which might be used as candidate components in vaccines against CDT-producing bacteria, including H. ducreyi.     

Influences of diet and surgical trauma on serum alkaline DNase activity levels.

Changes in serum alkaline DNase activities might predict the therapeutic response in various malignant diseases. A decrease in serum alkaline DNase activity within days from the onset of therapy has been related to tumour necrosis and may be a possible sign of clinical response to effective treatment. To study if changes in serum alkaline DNase activity could be induced by non-tumour related tissue destruction, sera were collected on several occasions perioperatively in 18 patients undergoing surgery for benign gynaecological disease. Thirty apparently healthy women served as the control group. A significant decrease (P less than 0.001) in serum alkaline DNase activity was observed after an overnight fast in both groups of women. In contrast to the control women, the operated patients showed a significant decrease (P less than 0.001) in serum alkaline DNase activity throughout the operative period and 1 week postoperatively. We conclude that serum alkaline DNase activity is influenced by dietary factors as well as surgical trauma. These factors may limit the clinical usefulness of SADA in patients with cancer.     

The burden of rheumatoid arthritis and access to treatment: determinants of access

As part of the study “The Burden of Rheumatoid Arthritis (RA) and Patient Access to Treatment”, this paper reviews the impact on access to RA drugs of the approval processes, pricing and funding decisions and times to market (access) in different countries. In addition, an overview of health technology assessments (HTA) and the economic literature related to RA treatments is provided. The time from approval to market access ranged from immediate to over 500 days in the countries included in the study. A total of 55 HTA reports were identified, 40 of them in the period between 2002 and 2006; 29 were performed by European HTA agencies, 14 in Canada and 7 in the United States. A total of 239 economic evaluations related to RA were identified in a specialized health economic database (HEED).

     

Which strategy should be applied? Design of a Norwegian epidemiological survey on chronic headache

Background –  Large-scale population-based epidemiological surveys on chronic headache based on clinical interview by a physician are lacking.
Aims of the study –  To describe a method that aims to provide valid information on chronic headache.
Method –  A self-administered questionnaire including two questions about headache frequency within the last month and within the last year was used to screen for possible chronic headache. Respondents with self-reported headache more than half of the days were interviewed by neurological residents with experience in headache diagnostics.
Discussion –  Previous studies have shown that a single question from a self-administered questionnaire can be used to screen for chronic headache. However, a precise headache diagnosis requires an interview by a physician experienced in headache diagnostics, as diagnoses extracted from questionnaires or provided by lay interviewers are not sufficiently precise.
Conclusions –  A combination of a screening questionnaire and a clinical interview by a physician is likely to be a cost-effective method to conduct an epidemiological survey on chronic headache.     

Experiencing neonatal death: an ambivalent transition into motherhood

OBJECTIVE: To illuminate the lived experience of women facing the threat of lossing their newborn child and then experiencing the reality of their infant's death. STUDY DESIGN: Sixteen women were interviewed approximately 2 years after the death of their infant using a hermeneutic phenomenological approach. FINDINGS: The main theme was ambivalent transition into motherhood. The women went through the whole life-span of their infant during a very short time. The women's narratives were interpreted as broken expectations, total confusion, reality awareness, consciously leave-taking, and elusive grief. CONCLUSIONS: Women need the opportunity to evolve their own patterns and rhythms in the ambivalent transition from expected motherhood to experiencing neonatal dying and death. Knowledge about the individuality of this process may assist nurses in improving the quality of care.     

On the unconscious subcortical origin of human fear

Consistent with the hypothesis that the amygdala is central to fear activation, brain imaging studies show that fear stimuli activate the amygdala, even when conscious recognition is prevented by backward masking. The bulk of the data suggest that the amygdala can be activated from potentially accessible but unattended fear stimuli. Activation of the amygdala facilitates low level visual processing. Several lines of evidence suggest that activation of the amygdala is mediated by a subcortical pathway. Thus, according to data from patients with lesions in the primary visual cortex, the amygdala can be activated in the absence of cortical processing. There is considerable support for the hypothesis that visual stimuli can access the amygdala via a pathway that includes the superior colliculus and the pulvinar nucleus of the thalamus. These data are consistent with an evolutionary argument, focusing of the role of snakes as a predator on primates.