Risk factors for subtherapeutic levels of posaconazole tablet

Background

Posaconazole is the prophylactic antifungal of choice for patients with haematological malignancies at high risk of invasive fungal infections (IFIs). Studies have demonstrated that subtherapeutic concentrations of posaconazole are associated with breakthrough fungal infections and specific risk factors for subtherapeutic troughs associated with the suspension formulation have been identified. However, these risk factors have not been evaluated in a large patient population with the recently approved tablet formulation.

Objectives

To determine the risk factors for subtherapeutic posaconazole troughs associated with the tablet formulation in patients receiving posaconazole as IFI prophylaxis.

Patients and methods

From 1 February 2013 to 31 March 2015 all posaconazole serum trough concentrations were evaluated. A total of 157 patients receiving posaconazole tablet for prophylaxis during induction therapy for haematological malignancies and allogeneic stem cell transplant recipients with graft-versus-host disease were included for analysis.

Results

Overall, 28 patients (18%) had subtherapeutic troughs (<700 ng/mL). Patients were more likely to have subtherapeutic troughs if they had diarrhoea (n = 24; 83%) (P < 0.001), were receiving a proton pump inhibitor (n = 27; 93%) (P = 0.016) and weighed >90 kg (n = 14; 48%) (P = 0.047).

Conclusions

While the posaconazole tablet has provided more consistent therapeutic concentrations when compared with the suspension there may still be a role for therapeutic drug monitoring (TDM). These results may guide us to a specific population in which TDM is necessary to identify subtherapeutic troughs.

Simultaneous Urography and Determination of Glomerular Filtration Rate

The total plasma clearance of iohexol at urography and 51Cr-EDTA was compared in 31 patients with di- or tetraparesis. A reference 51Cr-EDTA clearance was also performed 24 hours prior to the urography. The GFR was calculated from one, 2 or 4 plasma samples collected 180, 210, 240 and 270 min after the injection. An X-ray fluorescence analyzer was used for the analysis of iohexol in plasma as well as the contrast medium clearance calculations. It was shown that single or multiple sample clearance of iohexol and 51Cr-EDTA were equivalent methods for measurement of the GFR. The GFR was not affected by iohexol in a dose routinely used for urography. It was concluded that the patient comfort is improved if 51Cr-EDTA clearance is replaced by contrast medium clearance in association with urography.

Primary Chronic Osteomyelitis of the Jaws in Children: An Update on Pathophysiology, Radiological Findings, Treatment Strategies, and Prospective Analysis of Two Cases

Objective. Primary chronic osteomyelitis (PCO) of the jaws in children is associated with pain, trismus, and swelling. In children, temporomandibular joint involvement is rare and few studies have been published due to the relatively low incidence. This paper presents two cases of mandibular PCO in children with the involvement of the collum mandibulae. In addition, a review of the literature regarding demographic data, histological, radiological, and laboratory findings, and treatment strategies of PCO was also performed. Material and Methods. Prospective analyses of two PCO cases. A PubMed search was used and the articles were sorted according to their corresponding key area of focus. Results. Review of the literature revealed twenty-four cases of PCO with two cases of mandibular condyle involvement. The mean age was 18 years; the male to female ratio was 1 : 3. Most of the patients were treated with anti-inflammatory drugs in combination with decortication. Clinical recurrence was seen in 7 cases. Conclusion. A combination of anti-inflammatory drugs and surgical intervention appears to be the first choice of treatment. However, surgical removal of necrotic tissue adjacent to collum mandibulae has its limitations in children. Further investigations are of utmost importance in order to increase our knowledge and understanding of this disease.

Staphylococcal cassette chromosome mec (SCCmec) and arginine catabolic mobile element (ACME) in Staphylococcus epidermidis isolated from prosthetic joint infections

The aim of the present study was to characterise the staphylococcal cassette chromosome mec (SCCmec) in Staphylococcus epidermidis isolated from prosthetic joint infections (PJIs) and, if possible, assign them to any of the presently known SCCmec types. In addition, the isolates were examined for the presence of the arginine catabolic mobile element (ACME). Sixty-one S. epidermidis isolates obtained from PJIs and 24 commensal S. epidermidis isolates were analysed. The mecA gene was detected in 49 of the 61 (80 %) PJI isolates and in four of the 24 (17 %) commensal isolates, and the composition of the SCCmec was further analysed. SCCmec types I and IV were the most common types among the PJI isolates. However, for over half (57 %) of the isolates, it was not possible to assign an SCCmec type. ACME was detected in eight (13 %) of the PJI isolates and in 14 (58 %) of the commensal isolates. The characterisation of the SCCmec elements revealed a large heterogeneity, with a high frequency of isolates carrying more than one type of the ccr gene complex. ACME was more common among the commensal isolates and may represent a survival benefit for S. epidermidis colonising healthy individuals in the community.

Selective inhibitors of nuclear export show that CRM1/XPO1 is a target in chronic lymphocytic leukemia

The nuclear export protein XPO1 is overexpressed in cancer, leading to the cytoplasmic mislocalization of multiple tumor suppressor proteins. Existing XPO1-targeting agents lack selectivity and have been associated with significant toxicity. Small molecule selective inhibitors of nuclear export (SINEs) were designed that specifically inhibit XPO1. Genetic experiments and X-ray structures demonstrate that SINE covalently bind to a cysteine residue in the cargo-binding groove of XPO1, thereby inhibiting nuclear export of cargo proteins. The clinical relevance of SINEs was explored in chronic lymphocytic leukemia (CLL), a disease associated with recurrent XPO1 mutations. Evidence is presented that SINEs can restore normal regulation to the majority of the dysregulated pathways in CLL both in vitro and in vivo and induce apoptosis of CLL cells with a favorable therapeutic index, with enhanced killing of genomically high-risk CLL cells that are typically unresponsive to traditional therapies. More importantly, SINE slows disease progression, and improves overall survival in the Eμ-TCL1-SCID mouse model of CLL with minimal weight loss or other toxicities. Together, these findings demonstrate that XPO1 is a valid target in CLL with minimal effects on normal cells and provide a basis for the development of SINEs in CLL and related hematologic malignancies.

Predominance of staphylococcal cassette chromosome mec (SCCmec) type IV among methicillin-resistant Staphylococcus aureus (MRSA) in a Swedish county and presence of unknown SCCmec types with Panton-Valentine leukocidin genes

Methicillin-resistant Staphylococcus aureus (MRSA) is an established nosocomial pathogen, but has recently begun to appear in the community. The clones in the community may not have originated in the hospital setting, and are referred to as community-acquired MRSA (CA-MRSA). Resistance to methicillin is mediated by the gene mecA, which is carried by the mobile genetic element staphylococcal cassette chromosome mec (SCCmec). SCCmec typing (I-IV) of all clinical isolates of MRSA (n = 92) from 1987 to 2004 in Orebro County, Sweden, was performed by real-time LightCycler PCR to detect the essential genetic components mecA, mecR1, IS1272, ccrA and ccrB. Forty-one isolates harboured type IV SCCmec, of which ten could be classified further as subtype IVa, and 27 as subtype IVc. No isolates belonged to subtype IVb, but four isolates could not be subtyped, and may be examples of novel type IV SCCmec subtypes. Thirty-five MRSA isolates, assigned to six different pulsotypes by pulsed-field gel electrophoresis, did not belong to SCCmec types I-IV. The Panton-Valentine leukocidin (PVL) genes were identified in two of these pulsotypes. Only SCCmec type IV has been associated previously with the PVL toxin, but the results suggest that new PVL-positive clones with novel SCCmec types may be arising and disseminating in the community.

The N400 component in parents of children with specific language impairment

Children with specific language impairment (SLI) often have a family history of language disorder. In this study, ERPs in response to a visual semantic priming task were recorded in parents of children with SLI. Despite equal performance, the ERPs displayed differences in language processing: larger N400 amplitudes indicated that the parents, especially the fathers, were less primed by the preceding context. Difference waveforms showed that the fathers of SLI children, contrary to controls, had less differentiated responses to congruent versus incongruent sentences. We propose that the N400 observations may be residual markers of past language deficiencies in the fathers. No differences in the N400 effect were found in the mothers of SLI children.

A physical and transcriptional map of the preaxial polydactyly locus on chromosome 7q36

Preaxial polydactyly is a congenital hand malformation that includes duplicated thumbs, various forms of triphalangeal thumbs, and duplications of the index finger. A locus for preaxial polydactyly has been mapped to a region of 1.9 cM on chromosome 7q36 between polymorphic markers D7S550 and D7S2423. We constructed a detailed physical map of the preaxial polydactyly candidate region. With a combination of methods we identified and positioned 11 transcripts within this map. By recombination analysis on families with preaxial polydactyly, using newly developed polymorphic markers, we were able to reduce the candidate region to approximately 450 kb. The homeobox gene HLXB9, a putative receptor C7orf2, and two transcripts of unknown function, C7orf3 and C7orf4, map in the refined candidate region and have been subjected to mutation analysis in individuals with preaxial polydactyly.

Phage presentation and affinity selection of a deletion mutant of human interleukin-3

A deletion derivative of the cytokine human interleukin-3 (hIL-3(15-125), comprising amino acids 15-125 of the native protein) was produced as a fusion to the filamentous phage surface protein pIII. The cytokine was detected in association with phage particles by protein immunoblotting. Compared to an equivalent quantity of soluble-cytokine, phage-presented hIL-3(15-125) exhibited reduced biological activity in a hIL-3-dependent cell proliferation assay. The reduction in activity was attributable to presence of phage particles in the assay, rather than directly owing to physical incorporation of the cytokine into the phage particle. Owing to the position of the amber codon in the phagemid vector, the phagemid-produced free hIL-3(15-125) species (designated hIL-3(15-125) epsilon) had 20 amino acids appended to its C-terminus; hIL-3(15-125) epsilon did not exhibit reduced bioactivity. hIL-3(15-125)-presenting phage were affinity-selected with either a hIL-3-reactive polyclonal antibody or with cells expressing the heterodimeric hIL-3 receptor. These data are consistent with the use of phage-display technology for the affinity selection of hIL-3 variants with modified biological properties.

Thoughts before whistling

Whistleblowing is a public alert by an insider of an organisation to a practice or concerning potential they observe in the organisation. This paper proposes that the risk, values at stake, timeliness and manner of complaint be considered before a whistle is blown. It also notes education and monitoring mechanisms.

Simultaneous urography and determination of glomerular filtration rate. A comparison of total plasma clearances of iohexol and 51Cr-EDTA in plegic patients

The total plasma clearance of iohexol at urography and 51Cr-EDTA was compared in 31 patients with di- or tetraparesis. A reference 51Cr-EDTA clearance was also performed 24 hours prior to the urography. The GFR was calculated from one, 2 or 4 plasma samples collected 180, 210, 240 and 270 min after the injection. An X-ray fluorescence analyzer was used for the analysis of iohexol in plasma as well as the contrast medium clearance calculations. It was shown that single or multiple sample clearance of iohexol and 51Cr-EDTA were equivalent methods for measurement of the GFR. The GFR was not affected by iohexol in a dose routinely used for urography. It was concluded that the patient comfort is improved if 51Cr-EDTA clearance is replaced by contrast medium clearance in association with urography.

A survey of Sydney adults about the conduct of medical research

A representative sample of the adult Sydney population was surveyed and asked for their opinion on medical research. The community was found to support research, within certain limits. Those limits depended on the individual therapeutic benefit and the degree of invasiveness of the research. Stricter limits were identified for child research.

A human monoclonal autoantibody recognizes a neoantigen on glycoprotein IIIa expressed on stored and activated platelets

We prepared a heterohybrid cell line that secretes a human IgM monoclonal autoantibody that recognizes an antigen found on thrombin-activated or stored platelets. The surface expression of the epitope recognized by this autoantibody, 5E5, increases with time as platelets age in vitro, suggesting that it may represent a senescence or activation-specific antigen. 5E5 binds to the purified platelet membrane glycoprotein (GP) IIb-IIIa complex in an enzyme-linked immunosorbent assay (ELISA). In an immunoblot technique, 5E5 binds to a protein with an apparent mol wt of 95,000, which is identical to that of GPIIIa under nonreduced conditions. In crossed immunoelectrophoresis (CIE), the predominant antigen recognized by 5E5 is contained in the GPIIb-IIIa precipitin arc. An additional precipitin arc recognized by 5E5 is often observed only on gels derived from lysates of platelets stored under blood bank conditions for greater than 3 days. These findings illustrate the usefulness of human monoclonal antibodies for the identification of membrane neoantigens expressed as a result of platelet activation or revealed as platelets age in vitro.

On the mechanism of nucleolar dominance in mouse-human somatic cell hybrids

The mechanism of nucleolar dominance was studied in two lines of mouse-human somatic hybrids. Both lines had preferentially lost human chromosomes but had retained significant amounts of both mouse and human ribosomal genes (genes coding for the 18S, 5.8S, and 28S RNAs of ribosomes). However, the human ribosomal genes were repressed, and only mouse ribosomal genes were expressed. Soluble transcription extracts from the hybrids were able to initiate RNA synthesis accurately on a cloned mouse ribosomal gene but were unable to initiate accurately on a human ribosomal gene. This suggests that nucleolar dominance in these hybrids is due to the loss or inactivation of the gene for a specificity factor required to recognize the human ribosomal gene promoter.

Human monoclonal antibody against Forssman antigen

Hybrid cells formed between human lymphocytes and mouse myeloma cells produce human immunoglobulin in culture. Stable antibody-producing cell lines can be isolated after multiple cycles of low-density passage, cloning, and continued selection for immunoglobulin production. The origin and characteristics of a hybrid of human and mouse cells is described. This hybrid produces high concentrations (8.3 micrograms per milliliter) of human immunoglobulin M reactive with the terminal disaccharide of the Forssman glycolipid. These findings point to the potential use of human-mouse hybrid cells as a source of human monoclonal antibodies for therapeutic and diagnostic purposes.

Congo red dichroism with dispersed amyloid fibrils, an extrinsic cotton effect

The spectral absorption, optical rotatory dispresion, and circular dichroism associated with interaction of Congo red dye with partly purified suspensions of amyloid fibril fragments were examined. A set of phenomena consistent with a Cotton effect was found. A nearly identical set of phenomena was obtained with poly-L-lysine in its alpha-helical form. The dichroism seen when Congo red binds to amyloid substance in tissue sections can also be interpreted as a Cotton effect. This suggests that some special conformation, presumably in protein, is present in a major constituent of amyloid. This conformation is not present in gamma globulin, Bence-Jones protein, albumin, fibrinogen, or other proteins tested so far. These and other optical properties of amyloid substance can be used to compare amyloid deposits in different human cases and in different species. Extension of the use of polarization microscopy with other dyes that bind to other substances in tissue sections should permit more exquisite probing of the conformation of important macromolecules in situ in cells and tissues than has hitherto been possible.