Tumor necrosis factor inhibits conversion of dehydroepiandrosterone sulfate (DHEAS) to DHEA in rheumatoid arthritis synovial cells: a prerequisite for local androgen deficiency

OBJECTIVE: Use of anti-tumor necrosis factor (anti-TNF) antibody therapy in rheumatoid arthritis (RA) has expanded our understanding of possible mechanisms by which this treatment reduces inflammation. Beyond its effects on local immune responses, anti-TNF treatment may also modulate the local hormone supply. Because androgens are thought to inhibit immune responses, their presence in inflamed tissue is an additional important antiinflammatory factor. METHODS: We investigated conversion of the ubiquitous dehydroepiandrosterone sulfate (DHEAS), the biologically inactive precursor of DHEA, to the androgen DHEA in mixed synovial cells from patients with RA and patients with osteoarthritis (OA), making use of thin-layer chromatography and phosphorimaging. Using immunohistochemical analysis, we detected the key enzyme, steroid sulfatase. RESULTS: DHEAS-to-DHEA conversion in synovial cells from patients with RA was significantly lower than that in synovial cells from patients with OA (mean +/- SEM 3.3 +/- 0.5% versus 6.0 +/- 0.9% of applied (3)H-DHEAS per 10(6) synovial cells; P = 0.042). In RA, but not in OA, the level of converted (3)H-DHEA was inversely correlated with the density of synovial macrophages (for RA, R(rank) = -0.725, P = 0.005; for OA, R(rank) = 0.069, P not significant [NS]) and T cells (for RA, R(rank) = -0.621, P = 0.024; for OA, R(rank) = 0.247, P NS). Double immunohistochemistry analysis revealed that steroid sulfatase was located mainly in synovial macrophages but was also observed in fibroblasts. Neutralization of TNF largely up-regulated the conversion of DHEAS to DHEA in RA, but not in OA. A similar neutralizing effect was observed with polyclonal human immunoglobulins; this effect is most probably mediated via TNF neutralization at low TNF concentrations. CONCLUSION: These data indicate that TNF inhibits the conversion of DHEAS to DHEA in RA synovial cells. Because androgens are antiinflammatory mediators, TNF-induced inhibition of the local androgen supply is a supplementary proinflammatory factor. Consequently, anti-TNF strategies may also exert their positive effects by increasing tissue androgens.     

Ovarian intrafollicular processes as a target for cigarette smoke components and selected environmental reproductive disruptors

Steroidogenesis, expansion of oocyte-cumulus complex, and meiotic maturation of the oocyte represent intrafollicular processes taking important part in the background of successful fertilisation. The reproductive health of female could be affected by a number of endogenous as well as exogenous factors, such as exposure to agents from specific lifestyle habits, environmental pollutants with endocrine disrupting properties, or heavy metals. Published data indicate that exposure to chemicals may cause alterations in reproductive behavior and contribute to sub-fecundity, infertility, or ovarian failure. Female reproductive functions can be compromised by exposure to toxic chemicals at a variety of sites, including ovary or reproductive tract. Substantial harmful effects of cigarette smoke on fecundity and reproduction have become apparent but are not generally appreciated. The effects of cigarette smoke components (cadmium, nicotine, cotinine) absorbed into the organism on intrafollicular processes may thus in part explain the negative impact of smoking on female fertility. Moreover, it is now evident that a variety of man-made pollutants present in the environment are capable to disrupt normal endocrine function in many species. Examples of these "endocrine disrupters" include plasticizers, such as phthalates and bisphenol A. The effects of selected environmental chemicals on the processes of steroidogenesis, expansion of oocyte-cumulus complex, and meiotic maturation of the oocyte are summarized in the present paper and possible mechanisms of action of these agents are suggested. However, for complete understanding the mechanisms by which chemical agents from the environment can affect the intrafollicular processes, a lot of further investigation is needed.     

Combination therapy of trichloroacetic acid,human autologous fibroblast injection and fibroblast seeded microfibrous collagen scaffold as a novel treatment for osteomyelitis diabetic foot ulcer

A severe complication associated with diabetes is diabetic foot ulcer (DFU). Most patients with DFU require amputation. Although treatment of non-healing diabetic ulcers is challenging, the use of novel therapies can be effective. In this report, we present the case of a woman with type 2 diabetes with DFU-related osteomyelitis, who was treated with a combination therapy of trichloroacetic acid, calcium alginate and foam dressings, human autologous fibroblast injection, and a fibroblast cell-seeded collagen scaffold. The results showed the positive effects of combination therapy on DFU. In the initial treatment, the wound area was measured to be 14 × 7 cm², with a depth of 4 cm. After 6 months, the wound was measured to be 1.5 cm², showing a 90% reduction of the wound area. Overall, this combination therapy was highly effective in the treatment of DFU-related osteomyelitis, and could markedly prevent amputation among DFU patients.     

Multilocus Sequence Analysis of Clinical “Candidatus Neoehrlichia mikurensis” Strains from Europe

“Candidatus Neoehrlichia mikurensis” is the tick-borne agent of neoehrlichiosis, an infectious disease that primarily affects immunocompromised patients. So far, the genetic variability of “Ca. Neoehrlichia” has been studied only by comparing 16S rRNA genes and groEL operon sequences. We describe the development and use of a multilocus sequence analysis (MLSA) protocol to characterize the genetic diversity of clinical “Ca. Neoehrlichia” strains in Europe and their relatedness to other species within the Anaplasmataceae family. Six genes were selected: ftsZ, clpB, gatB, lipA, groEL, and 16S rRNA. Each MLSA locus was amplified by real-time PCR, and the PCR products were sequenced. Phylogenetic trees of MLSA locus relatedness were constructed from aligned sequences. Blood samples from 12 patients with confirmed “Ca. Neoehrlichia” infection from Sweden (n = 9), the Czech Republic (n = 2), and Germany (n = 1) were analyzed with the MLSA protocol. Three of the Swedish strains exhibited identical lipA sequences, while the lipA sequences of the strains from the other nine patients were identical to each other. One of the Czech strains had one differing nucleotide in the clpB sequence from the sequences of the other 11 strains. All 12 strains had identical sequences for the genes 16S rRNA, ftsZ, gatB, and groEL. According to the MLSA, among the Anaplasmataceae, “Ca. Neoehrlichia” is most closely related to Ehrlichia ruminantium, less so to Anaplasma phagocytophilum, and least to Wolbachia endosymbionts. To conclude, three sequence types of infectious “Ca. Neoehrlichia” were identified: one in the west of Sweden, one in the Czech Republic, and one spread throughout Europe.     

PRDM16 binds MED1 and controls chromatin architecture to determine a brown fat transcriptional program

PR (PRD1–BF1–RIZ1 homologous) domain-containing 16 (PRDM16) drives a brown fat differentiation program, but the mechanisms by which PRDM16 activates brown fat-selective genes have been unclear. Through chromatin immunoprecipitation (ChIP) followed by deep sequencing (ChIP-seq) analyses in brown adipose tissue (BAT), we reveal that PRDM16 binding is highly enriched at a broad set of brown fat-selective genes. Importantly, we found that PRDM16 physically binds to MED1, a component of the Mediator complex, and recruits it to superenhancers at brown fat-selective genes. PRDM16 deficiency in BAT reduces MED1 binding at PRDM16 target sites and causes a fundamental change in chromatin architecture at key brown fat-selective genes. Together, these data indicate that PRDM16 controls chromatin architecture and superenhancer activity in BAT.     

Frequency distribution of antimalarial drug-resistant alleles among isolates of Plasmodium falciparum in Purworejo district, Central Java Province, Indonesia

Treatment failures to the first- and second-lines antimalarial drugs chloroquine and sulfadoxine-pyrimethamine have increased in the Purworejo district on the island of Java, Indonesia. A molecular epidemiologic study was conducted to determine the frequency distribution of mutant alleles of the genes associated with the resistance among the isolates of Plasmodium falciparum from the area. Analyses using a polymerase chain reaction and restriction fragment length polymorphism showed that nearly all of the 111 samples carried mutant alleles in genes associated with chloroquine resistance: P. falciparum multi-drug resistance 1 (pfmdrl) 86Y (92%), 1042D (4.5%), and P. falciparum chloroquine resistance transporter (pfcrt) 76T (99.1%). Mutant alleles of the in the dihydrofolate reductase (dhfr) gene were also high (84.7%), either as 108N and 108T or paired with 59R, and 16V, respectively. Mutant alleles in the dihydropteroate synthase gene were the least common, either as a single 437G mutation (35.3%) or paired with 540E (26.5%). These results are consistent with the antimalarial drug resistance situation in the area and emphasize the need for a proper treatment strategy.     

Improved extubation rates and earlier liberation from mechanical ventilation with implementation of a daily spontaneous-breathing trial protocol

BACKGROUND: Daily spontaneous-breathing trials (SBTs) are promulgated as the best method for assessing readiness for discontinuation of mechanical ventilation. SBT protocols have also been shown to improve outcomes as opposed to wild-type implementation of daily SBT recommendations. Here we determine whether implementation of a mandatory, protocol-driven daily SBT on all ventilated patients in the ICU improves extubation rates and accelerates liberation from mechanical ventilation. STUDY DESIGN: A daily 30-minute SBT protocol was introduced into an academic surgical ICU in July 2005 and followed through September 2006. Decisions about next steps (continued mechanical support versus liberation) after each trial were recorded. Owing to the low liberation rate, physicians began (in January 2006) recording the reasons for continuing mechanical ventilation after a passing SBT. Differences in patient outcomes were compared for the first and last 8 weeks of the study period, corresponding to similar times in the academic and calendar years. RESULTS: Four hundred eighty-eight patients experienced 547 mechanical ventilation episodes from July 2005 to September 2006. A total of 2,835 safety evaluations for SBTs were completed. Rate of extubations of passing patients after the first 8 weeks of implementation (n = 73 patients) was 27% (35 extubations of 131 passed trials). This rate improved in the last 8 weeks to 42% (42 of 101) (p < 0.02) (n = 57 patients). Reintubation rate was similar at 6% for the first 8 weeks and 8% for the final 8 weeks (p = 0.65), including self-extubations. CONCLUSIONS: Implementation of a daily SBT protocol resulted in improvement of extubation rates during the year of implementation without a change in the reintubation rate. Requesting that physicians enumerate reasons for continuing mechanical ventilation in the face of a passing breathing trial was associated with a sustained improvement in extubation rate.     

Wnt10b inhibits obesity in ob/ob and agouti mice

The Wnt family of secreted signaling molecules has profound effects on diverse developmental processes, including the fate of mesenchymal progenitors. While activation of Wnt signaling blocks adipogenesis, inhibition of endogenous Wnt/beta-catenin signaling by Wnt10b promotes spontaneous preadipocyte differentiation. Transgenic mice with expression of Wnt10b from the FABP4 promoter (FABP4-Wnt10b) have less adipose tissue when maintained on a normal chow diet and are resistant to diet-induced obesity. Here we demonstrate that FABP4-Wnt10b mice largely avert weight gain and metabolic abnormalities associated with genetic obesity. FABP4-Wnt10b mice do not gain significant body weight on the ob/ob background, and at 8 weeks of age, they have an approximately 70% reduction in visceral and subcutaneous adipose tissues compared with ob/ob mice. Similarly, on the lethal yellow agouti (A(y)) background, FABP4-Wnt10b mice have 50-70% less adipose tissue weight and circulating leptin at 5 months of age. Wnt10b-Ay mice are more glucose tolerant and insulin sensitive than A(y) controls, perhaps due to reduced expression and circulation of resistin. Reduced expression of inflammatory cytokines may also contribute to improved glucose homeostasis.