Late relapse of testis cancer

Most relapses of germ-cell tumors occur within 2 years of initial treatment. In 2% to 4% of patients, relapse may occur later. The retroperitoneum is the primary site of late relapse, and alpha-fetoprotein is the predominant marker. These tumors are highly resistant to chemotherapy. Surgical resection is the preferred treatment. If the recurrent disease is inoperable, chemotherapy may be instituted, followed by resection of residual masses. Patients successfully managed for testis cancer need lifelong surveillance.     

The influence of electrolyte composition on the in vitro charge-injection limits of activated iridium oxide (AIROF) stimulation electrodes

The effects of ionic conductivity and buffer concentration of electrolytes used for in vitro measurement of the charge-injection limits of activated iridium oxide (AIROF) neural stimulation electrodes have been investigated. Charge-injection limits of AIROF microelectrodes were measured in saline with a range of phosphate buffer concentrations from [PO(4)(3-)] = 0 to [PO(4)(3-)] = 103 mM and ionic conductivities from 2-28 mS cm(-1). The charge-injection limits were insensitive to the buffer concentration, but varied significantly with ionic conductivity. Using 0.4 ms cathodal current pulses at 50 Hz, the charge-injection limit increased from 0.5 mC cm(-2) to 2.1 mC cm(-2) as the conductivity was increased from 2 mS cm(-1) to 28 mS cm(-1). An explanation is proposed in which the observed dependence on ionic conductivity arises from non-uniform reduction and oxidation within the porous AIROF and from uncorrected iR-drops that result in an overestimation of the redox potential during pulsing. Conversely, slow-sweep-rate cyclic voltammograms (CVs) were sensitive to buffer concentration with the potentials of the primary Ir(3+)/Ir(4+) reduction and oxidation reactions shifting approximately 300 mV as the buffer concentration decreased from [PO(4)(3-)] = 103 mM to [PO(4)(3-)] = 0 mM. The CV response was insensitive to ionic conductivity. A comparison of in vitro AIROF charge-injection limits in commonly employed electrolyte models of extracellular fluid revealed a significant dependence on the electrolyte, with more than a factor of 4 difference under some pulsing conditions, emphasizing the need to select an electrolyte model that closely matches the conductivity and ionic composition of the in vivo environment.     

Increased lengthening rate decreases expression of fibroblast growth factor 2, platelet-derived growth factor, vascular endothelial growth factor, and CD31 in a rat model of distraction osteogenesis

BACKGROUND: The rate of lengthening has a profound impact on bone regeneration during distraction osteogenesis. Rapid distraction can delay or completely inhibit union, whereas distracting too slowly may lead to premature consolidation. However, the mechanisms responsible for retardation of healing due to rapid distraction have not been elucidated. This study explored whether rapid distraction alters the expression of certain angiogenic growth factors, in particular, fibroblast growth factor 2 (FGF-2), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF-AA), and subsequent new vessel formation as evidenced by platelet endothelial cellular adhesion marker expression (CD31), an indicator of vascular budding. METHODS: Unilateral femoral lengthenings were performed in 60 male Sprague-Dawley rats using a protocol that involved a 7-day latency period and distraction rates of either 0.5 (slow distraction) or 1.5 mm/d (fast distraction) for a total of 7.0 mm of lengthening. Animals were euthanized on postoperative days 8, 10, 12, 14, and 21 (n = 6 per time point and distraction rate). Expression of FGF-2, VEGF, PDGF-AA, and CD31 was characterized immunohistochemically. RESULTS: Cellular staining of FGF-2, PDGF-AA, VEGF, and CD31 was reduced on days 8 to 12 in the regenerate of the fast-distraction animals compared with the slow-distraction animals. Staining of all growth factors was weak on days 14 and 21 at the slow rate and absent at the fast rate. Regardless of time point, a similar spatial localization of growth factor expression was observed at the 2 rates of distraction. CONCLUSIONS: The reduced expression of angiogenic growth factors and CD31, a marker of new vessel formation, indicates that the angiogenic cascade and new vessel formation required for effective bone healing is disrupted at a distraction rate of 1.5 mm/d in a rat model of limb lengthening. CLINICAL RELEVANCE: Delayed bone healing with rapid distraction may be due in part to decreased cellular signaling required for angiogenesis. It may be possible to improve bone healing at increased distraction rates with the appropriately timed administration of growth factors.     

Antibody persistence after two vaccinations with either FSME-IMMUN® Junior or ENCEPUR® Children followed by third vaccination with FSME-IMMUN® Junior

Tick-borne encephalitis (TBE) vaccination strategies to induce optimal seroprotection in children are under constant evaluation. This multi-center, randomized, controlled, phase III clinical study examined antibody persistence in children aged 1-11 y following two prospectively administered doses of either the FSME-IMMUN? Junior or Encepur Children? vaccines, as well as investigating the immunogenicity, safety and vaccine interchangeability of a third vaccination with FSME-IMMUN(?) Junior. A high level of antibody persistence was observed in all subjects 6 mo after the first of two vaccinations with either pediatric TBE vaccine. Based on both immunological tests and viral antigens used, slightly higher seropositivity rates and higher GMCs /GMTs were found in children vaccinated with FSME-IMMUN? Junior compared with those who received Encepur? Children. Seropositivity rates across all age strata combined six months after the first vaccination with FSME-IMMUN? 0.25 mL Junior were 95.1% as determined by Immunozym ELISA, 93.2% as determined by Enzygnost ELISA and 95.3% as determined by NT; compared with 62.6%, 80.5% and 91.0% respectively after vaccination with Encepur? Children. A third vaccination with FSME-IMMUN(?) Junior induced 100% seropositivity in both study groups and was well tolerated as demonstrated by the low rates of systemic and injection site reactions. Subjects who received either FSME-IMMUN Junior? or Encepur(?) Children vaccine for the first two vaccinations and FSME-IMMUN Junior? for the third showed a comparably strong immune response regardless of the previous TBE vaccine administered, demonstrating that two vaccinations with Encepur? Children can successfully be followed by a third vaccination with FSME-IMMUN Junior?.     

MEASUREMENT OF THE REACTION BETWEEN THE FUNGICIDES CAPTAN OR FOLPET AND BLOOD THIOLS

Captan and folpet are two protectant fungicides that react with thiols. Current dermal risk assessment paradigms consider that 100% of the absorbed material is available systemically. Both fungicides are associated with duodenal tumors in mice after dietary administration and NOELs for effects leading to tumor formation have been established at approximately 400 ppm (60 mg/kg/day). Thus, it is important to quantify systemic exposure so as to establish a meaningful risk characterization. This study simultaneously mixed 14 C-captan and 14 C-folpet with blood at approximately 1 μg/mL (1 ppm) at 37°C, which served to refine earlier pre-GLP measurements made with nonradiolabeled material at 22°C. A series of experimental procedures was employed that progressively refined the ability to arrest and measure the chemical reaction from 0 to 31.1 s. Acetone (10 μL) containing 14 C-captan and 14 C-folpet, both at approximately 100 μg/mL, was delivered into 1 mL human blood contained in a 3-mL Hamilton syringe. The final captan concentration was 0.94 μg/mL and that of folpet was 1.06 μg/mL. The reaction was stopped by expressing the blood mixture into a centrifuge tube that contained 5 mL acetone and 80 μL 7.3 M phosphoric acid. Reaction vessels were placed on a vortex mixer at high speed. Unlabeled captan, folpet, (THPI; captan's main ring degradate), and (PI; folpet's main ring degradate) were contained in the acetone and served as ultraviolet markers during (HPLC). Extracts were passed through a Florisil silica gel column and analyzed by HPLC. Radioactivity in HPLC fractions was measured by liquid scintillation. The chemical reaction with thiols followed the first-order rate equation A t = A 0 e- kt, with rate kinetic constants of 0.718 (captan) and 0.141 (folpet). The resulting half-lives in blood were 0.97 s for captan and 4.9 s for folpet. Mass spectrometry confirmed that the respective imide rings (THPI and PI) were the only degradation products. Risk assessments that ignore this rapid degradation do not accurately estimate systemic exposure and are unnecessarily conservative.     

Mapping partner drug resistance to guide antimalarial combination therapy policies in sub-Saharan Africa

Resistance to artemisinin-based combination therapies (ACTs) threatens the global control of Plasmodium falciparum malaria. ACTs combine artemisinin-derived compounds with partner drugs to enable multiple mechanisms of clearance. Although ACTs remain widely effective in sub-Saharan Africa, long-standing circulation of parasite alleles associated with reduced partner drug susceptibility may contribute to the development of clinical resistance. We fitted a hierarchical Bayesian spatial model to data from over 500 molecular surveys to predict the prevalence and frequency of four key markers in transporter genes (pfcrt 76T and pfmdr1 86Y, 184F, and 1246Y) in first-level administrative divisions in sub-Saharan Africa from the uptake of ACTs (2004 to 2009) to their widespread usage (2010 to 2018). Our models estimated that the pfcrt 76T mutation decreased in prevalence in 90% of regions; the pfmdr1 N86 and D1246 wild-type genotypes increased in prevalence in 96% and 82% of regions, respectively; and there was no significant directional selection at the pfmdr1 Y184F locus. Rainfall seasonality was the strongest predictor of the prevalence of wild-type genotypes, with other covariates, including first-line drug policy and transmission intensity more weakly associated. We lastly identified regions of high priority for enhanced surveillance that could signify decreased susceptibility to the local first-line ACT. Our results can be used to infer the degree of molecular resistance and magnitude of wild-type reversion in regions without survey data to inform therapeutic policy decisions.

Artemisinin-based combination therapies (ACTs) are recommended as the first-line treatment for uncomplicated Plasmodium falciparum malaria worldwide (1). ACTs combine potent artemisinin-derived compounds and partner drugs with longer half-lives, allowing for dual mechanisms of action and prolonged antiparasitic action. Of the ACTs currently recommended by the World Health Organization, artemether-lumefantrine (AL) and artesunate-amodiaquine (AS-AQ) are the most commonly adopted first-line ACTs in sub-Saharan Africa (1). While efficacy remains high, recent reports of mutations associated with reduced artemisinin sensitivity in Rwanda and long-standing circulation of alleles associated with bidirectional impacts on partner drug susceptibility raise concern that ACT resistance may arise and spread in sub-Saharan Africa (2–4).Molecular markers are single nucleotide polymorphisms (SNPs), deletions, or copy number variations in the parasite genome that are associated with reduced susceptibility to antimalarial drugs. SNPs along two key transporter genes, P. falciparum chloroquine resistance transporter (pfcrt) and P. falciparum multidrug resistance 1 (pfmdr1), were first discovered to confer resistance to antimalarial drugs in the 1990s, primarily pfcrt 76T to chloroquine, and have since been implicated in impacting susceptibility to AL and AS-AQ (5). Notably, the partner drugs lumefantrine and AQ exert opposing selective pressures: parasites with genotype pfmdr1 86Y, Y184, 1246Y, and pfcrt 76T have reduced susceptibility to AQ, while pfmdr1 N86, 184F, D1246, and pfcrt K76 confer reduced susceptibility to lumefantrine (5–7). While data are strongest for partner drugs, artemisinins may also directly exert a selective pressure at pfmdr1 and other loci (8, 9).In southeast Asia, partner drug resistance arose rapidly in the wake of, and in some regions independently of, artemisinin resistance (10). In sub-Saharan Africa, it has been suggested that partner drug failure is expected to result in greater increases in malaria morbidity than would be observed from artemisinin resistance alone (4). The population prevalence of markers in pfcrt and pfmdr1 can indicate the level of clinical resistance or tolerance to the partner drugs AQ and lumefantrine (11). When used as a surveillance tool, molecular marker data can rapidly provide data to support modifications of local partner drugs and to sustain artemisinin-based treatment and prevention options. Despite broad consensus to scale up molecular surveillance for antimalarial resistance, few studies have proposed systematically designed approaches such as where sentinel sites should be located or how often sampling should be conducted (12, 13).We previously developed a database of studies assessing prevalence of partner drug resistance–associated markers in sub-Saharan Africa, supplementing an existing database by the Worldwide Antimalarial Resistance Network (14, 15). That work revealed important gaps in the geographic coverage of surveillance. We hypothesized that the geographic landscape of mutations associated with partner drug resistance exhibit spatial patterns that can be mapped and leveraged to determine sites needing additional surveillance. In this study, we use a hierarchical Bayesian spatial method to map the geographical distribution of key molecular markers in pfcrt and pfmdr1 in sub-Saharan Africa since the uptake of ACTs and analyze potential demographic and environmental determinants of resistance landscapes. We also identify potential regions for enhanced surveillance based on the magnitude and direction of changes in genotypes over time, suggesting areas that may pose an increased risk of artemisinin emergence or spread (16). Our work will assist in strategic surveillance efforts to sustain first-line ACT partner drug efficacy in sub-Saharan Africa and inform future surveillance as new antimalarials are deployed and additional molecular markers are identified.     

Flare of pustular psoriasis after initiating ustekinumab therapy

Anti-tumor necrosis factor-α therapy has been paradoxically associated with the new development or worsening of existing psoriasis. We describe the case of a patient who experienced a flare of pustular psoriasis after initiating anti-interleukin-12/23 therapy, which subsequently improved following discontinuation of the drug.     

The complete genome sequence of Lactobacillus bulgaricus reveals extensive and ongoing reductive evolution

Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) is a representative of the group of lactic acid-producing bacteria, mainly known for its worldwide application in yogurt production. The genome sequence of this bacterium has been determined and shows the signs of ongoing specialization, with a substantial number of pseudogenes and incomplete metabolic pathways and relatively few regulatory functions. Several unique features of the L. bulgaricus genome support the hypothesis that the genome is in a phase of rapid evolution. (i) Exceptionally high numbers of rRNA and tRNA genes with regard to genome size may indicate that the L. bulgaricus genome has known a recent phase of important size reduction, in agreement with the observed high frequency of gene inactivation and elimination; (ii) a much higher GC content at codon position 3 than expected on the basis of the overall GC content suggests that the composition of the genome is evolving toward a higher GC content; and (iii) the presence of a 47.5-kbp inverted repeat in the replication termination region, an extremely rare feature in bacterial genomes, may be interpreted as a transient stage in genome evolution. The results indicate the adaptation of L. bulgaricus from a plant-associated habitat to the stable protein and lactose-rich milk environment through the loss of superfluous functions and protocooperation with Streptococcus thermophilus.