Inhibition of the cholesterol transporter ABCA1 by probucol decreases capacitation and tyrosine phosphorylation of dog spermatozoa, and is dose dependent

The ATP binding cassette (ABC) transporter molecule ABCA1 participates in the cholesterol transport within and through cell membranes. We recently demonstrated that in dog spermatozoa, capacitation could be decreased with probucol (PRO), an ABCA1 specific antagonist. In this study, a dose-effect relationship of PRO on dog sperm capacitation, tyrosine phosphorylation and cholesterol efflux from the sperm plasma membrane was investigated. A total of 16 ejaculates from dogs of different breeds, aged 2-4 years were used. Sperm motility and membrane integrity in the main fraction was determined by CASA. Samples were stained with a boron dipyrromethene difluoride (BODIPY) fluorophore (P9672, Sigma- Aldrich, A) diluted in DMSO at a final concentration of 0.4 μM. All samples were divided into 5 aliquots, with 0, 100, 250, 500 and 1000 μM of PRO. After incubation at 37 °C for 2 h, PI was added and flow cytometry performed. All aliquots were examined for capacitation and acrosome reaction by using the CTC assay and tyrosine phosphorylation (TP). Membrane integrity was measured in all aliquots to investigate the effect of PRO on cell membranes. Membrane integrity did not differ between controls (0 μM), and 100, 250 and 500 μM PRO, but decreased with 1000 μM PRO (p < 0.05). Increasing PRO concentration decreased the percentage alive cells with cholesterol efflux per PRO group (0 μM: 77.8 ± 10.6%, 100 μM: 63.7 ± 11.7%, 250 μM: 52.1 ± 12.9%, 500 μM: 37.7 ± 11.6%, 1000 μM: 33.1 ± 14.4%; p < 0.05), decreased head and entire tail phosphorylated cells (0 μM: 34.6%, 1000 μM: 5.1% p < 0.05); and decreased the percentage capacitated cells (maximum with PRO 500 μM: capacitated vs. control: 54.2 ± 17% vs 25 ± 7.7%, p < 0.05). Conclusion: PRO decreased the cholesterol efflux, and decreased tyrosine phosphorylation and capacitation in a dose-dependent manner. This suggests a strong involvement of the ABCA1 transporter in different functional aspects of sperm capacitation in dogs.

Diagnostically challenging human papillomavirus-associated primary squamous cell carcinoma of the rectum with metastasis in both ovaries: a case report

Introduction

Squamous cell carcinomas of the rectum are extremely rare and their pathogenesis is still under debate. Their proper diagnosis and treatment may thus be challenging.

Case presentation

A 52-year-old Caucasian woman was transferred to our department with a history of pelvic pain. Colonoscopy revealed a small tumorous lesion of the upper rectum and an endoscopic biopsy showed infiltration of the rectal mucosa by a squamous cell carcinoma. Afterward, tumorous lesions were found on imaging in both her ovaries. A laparoscopy with adnexectomy and anal mapping was performed and revealed tumor masses of squamous cell carcinoma in both ovaries. Based on the large size of the ovarian tumors and the concurrence of extensive, partly ciliated, macrocystic epithelium in one of the ovaries, a diagnosis of ovarian squamous cell carcinoma arising from a mature teratoma was rendered. However, human papillomavirus genotyping analyses were positive for human papillomavirus-16 in both the rectal tumor and ovarian tumors leading to a final diagnosis of a human papillomavirus-associated rectal squamous cell carcinoma metastatic to both ovaries. Neoadjuvant chemoradiation therapy of her rectum, total mesorectal excision, and hysterectomy were performed followed by adjuvant chemotherapy.

Conclusion

Colorectal squamous cell carcinoma is a rare disease. In cases of colorectal squamous cell carcinoma, metastatic disease at any other location has to be excluded. Human papillomavirus genotyping is essential in this context. Discussion of the treatment strategies should be interdisciplinary and include chemoradiation therapy and radical surgery.

Intratympanic steroid use for idiopathic sudden sensorineural hearing loss: current otolaryngology practice in Germany and Austria

AIMS

The frequency of the use of intratympanic steroids (ITS) as a treatment for idiopathic sudden sensorineural hearing loss (ISSNHL) in Europe is still unknown and remains a contentious issue amongst otolaryngologists. We undertook a survey of otolaryngologists in Germany and Austria to establish if there is any professional consensus with which to form a protocol for its use.

METHODS

A survey of 21 questions was distributed electronically to otolaryngologists in Germany and Austria and data on demographics, indications for intratympanic treatment, procedure, follow-up, and outcomes were analysed.

RESULTS

We received 908 responses. 49.1% of otolaryngologists used ITS for ISSNHL. Of those otolaryngologists who use ITS, 73.7% do not use it as primary treatment. 20.6% use ITS in conjunction with oral steroids for primary treatment and only 5.8% use ITS as monotherapy for primary treatment. 90.5% use ITS as salvage therapy. 81.1% do not consider the use of ITS after 2 weeks from the onset of symptoms. 8.3% used a tympanostomy tube and while the most commonly used steroid was dexamethasone at a concentration of 4 mg/ml (61%), a wide variety or other steroids and concentrations were used.

CONCLUSIONS

This survey illustrates wide variation of current practice of intratympanic corticosteroid injection for ISSHL in Germany and Austria. In the absence of high-level evidence, knowing what current practice is allows clinicians to assess what they do against what their colleagues are doing, and if they do something very different, make them question their practice. Moreover, the obtained data will help to direct future clinical trials with the aim to compare the outcomes of more commonly used protocols.

Pathophysiologie der Chemotherapie-assoziierten Thrombose

Epidemiologische Daten haben gezeigt, dass die meisten antineoplastischen Therapien das Risiko für venöse aber auch arterielle thromboembolische Ereignisse von Tumorpatienten deutlich verstärken. Diese Übersichtsarbeit gibt einen Überblick über das Thromboserisiko, welches mit der Gabe verschiedener klassischer Chemotherapeutika, Angiogenese-Inhibitoren und Immunmodulatoren verbunden ist, sowie deren potenziell zugrundeliegenden Mechanismen. Trotz zahlreicher Studien zeigt die vorliegende Arbeit, dass man von einem umfassenden Verständnis der Chemotherapie-assoziierten Thrombose weit entfernt ist.

17q21.31 duplication causes prominent tau-related dementia with increased MAPT expression

To assess the role of rare copy number variations in Alzheimer's disease (AD), we conducted a case-control study using whole-exome sequencing data from 522 early-onset cases and 584 controls. The most recurrent rearrangement was a 17q21.31 microduplication, overlapping the CRHR1, MAPT, STH and KANSL1 genes that was found in four cases, including one de novo rearrangement, and was absent in controls. The increased MAPT gene dosage led to a 1.6-1.9-fold expression of the MAPT messenger RNA. Clinical signs, neuroimaging and cerebrospinal fluid biomarker profiles were consistent with an AD diagnosis in MAPT duplication carriers. However, amyloid positon emission tomography (PET) imaging, performed in three patients, was negative. Analysis of an additional case with neuropathological examination confirmed that the MAPT duplication causes a complex tauopathy, including prominent neurofibrillary tangle pathology in the medial temporal lobe without amyloid-β deposits. 17q21.31 duplication is the genetic basis of a novel entity marked by prominent tauopathy, leading to early-onset dementia with an AD clinical phenotype. This entity could account for a proportion of probable AD cases with negative amyloid PET imaging recently identified in large clinical series.

[Pathophysiology of chemotherapy-associated thrombosis]

Epidemiological studies revealed that most antineoplastic agents and regimes enhance the risk of venous and arterial thromboembolic events in cancer patients. The purpose of this article is to review clinical and pathophysiological data related to chemotherapy-associated thromboembolism under special consideration of newer treatment strategies, such as angiogenesis inhibitors and immunmodulatory agents. Despite numerous clinical and experimental studies it has to be concluded that we are far from a comprehensive understanding of the pathogenesis of chemotherapy-associated thrombosis.

Comparison between idiopathic deep vein thrombosis of the upper and lower extremity regarding risk factors and recurrence

BACKGROUND

The pathogenesis and natural course of idiopathic upper extremity deep vein thrombosis (UEDVT) are unclear.

OBJECTIVE

To compare patients with UEDVT and with idiopathic lower extremity deep vein thrombosis (LEDVT) regarding risk factors and recurrence.

METHODS

We followed 50 patients with first idiopathic UEDVT and 841 patients with first idiopathic LEDVT for an average of 59 and 46 months, respectively. We excluded patients with natural inhibitor deficiency, lupus anticoagulant, cancer, pregnancy, isolated pulmonary embolism (PE), or long-term antithrombotic treatment. The endpoint was recurrent venous thromboembolism (VTE).

RESULTS

In comparison to LEDVT patients, UEDVT patients were younger (38 +/- 13 years vs. 49 +/- 16 years, P < 0.001), slimmer (body mass index: 24 +/- 4 vs. 27 +/- 5, P < 0.001), less frequently had a family history of VTE (18% vs. 31%, P = 0.06) or concomitant PE (8% vs. 31%, P =0.001), were less frequently carriers of factor V Leiden (12% vs. 30%, P = 0.009), and had lower thrombin generation marker levels (D-dimer, 283 +/- 361 ng mL(-1) vs. 456 +/- 446 ng mL(-1), P < 0.001; peak thrombin, 298 +/- 101 nm vs. 363 +/- 111 nm, P = 0.001). Recurrence occurred in two of 50 patients with UEDVT (4%) and in 129 of 841 patients with LEDVT (15%). After 5 years, the likelihood of recurrence was 2% [95% confidence interval (CI) 0-6] among UEDVT patients and 19% (95% CI 16-22; P = 0.02) among LEDVT patients. As compared to LEDVT patients, the adjusted risk of recurrence was 0.26 (95% CI 0.06-1.05; P = 0.059) in UEDVT patients.

CONCLUSION

The pathogenesis and natural course of the disease differ between patients with idiopathic UEDVT and LEDVT.

Chemotherapy-induced thrombin generation via procoagulant endothelial microparticles is independent of tissue factor activity

BACKGROUND

Cisplatin-based chemotherapy predisposes cancer patients to thromboembolic events.

OBJECTIVES

To investigate whether endothelial damage, via formation of procoagulant endothelial microparticles (EMPs), contributes to cisplatin-related hypercoagulability.

METHODS

Cell viability and caspase-3/7 activities were assessed in two endothelial cell (EC) lines [human umbilical vein ECs (HUVECs) and human pulmonary microvascular ECs (HMVEC-Ls)] after exposure to cisplatin (1, 2.5, 5, 10 and 20 microm) for up to 120 h. Counts and procoagulant activity of EMPs were measured by flow cytometry and a thrombin generation assay, respectively. Tissue factor (TF) antigen and TF-dependent procoagulant activity of EMP were determined by enzyme-linked immunosorbent assay and a novel functional assay.

RESULTS

By inducing apoptosis, cisplatin dose- and time-dependently decreased the viability of confluent HUVECs and HMVEC-Ls. Progression of EC death was accompanied by an increased release of EMPs (relative increase at 20 microm cisplatin for 48 h vs. control: HUVECs 6.5-fold, P < 0.001; HMVEC-Ls 18.4-fold, P < 0.001). EMPs were highly procoagulant (relative increase at 20 microm cisplatin for 48 h vs. control: HUVECs 2.5-fold, P < 0.001; HMVEC-Ls 5.9-fold, P < 0.001). EMP-driven thrombin generation, however, was not dependent on TF: TF expression and TF procoagulant activity levels on microparticles were only marginal and EMP-associated thrombin generation remained unchanged when the extrinsic pathway was blocked by omission of factor VIIa and/or incubation with an anti-human TF antibody. In contrast, blocking of phospholipids by annexin V markedly diminished EMP-associated procoagulant activity.

CONCLUSIONS

In vitro, cisplatin induced the release of EMPs that showed TF-independent procoagulant activity.

A high-resolution linkage map for the Z chromosome in chicken reveals hot spots for recombination

A comprehensive linkage map for chicken chromosome Z was constructed as the result of a large-scale screening of single nucleotide polymorphisms (SNPs). A total of 308 SNPs were assigned to Z based on the genotype distribution among 182 birds representing several populations. A linkage map comprising 210 markers and spanning 200.9 cM was established by analyzing a small Red junglefowl/White Leghorn intercross. There was excellent agreement between the linkage map for Z and a recently released assembly of the chicken genome (May 2006). Almost all SNPs assigned to chromosome Z in the present study are on Z in the new genome assembly. The remaining 12 loci are all found on unassigned contigs that can now be assigned to Z. The average recombination rate was estimated at 2.7 cM/Mb but there was a very uneven distribution of recombination events with both cold and hot spots of recombination. The existence of one of the major hot spots of recombination, located around position 39.4 Mb, was supported by the observed pattern of linkage disequilibrium. Thirteen markers from unassigned contigs were shown to be located on chromosome W. Three of these contigs included genes that have homologues on chromosome Z. The preliminary assignment of three more genes to the gene-poor W chromosome may be important for studies on the mechanism of sex determination and dosage compensation in birds.

Full flexibility genotyping of single nucleotide polymorphisms by the GOOD assay

Recently a facile method for genotyping single nucleotide polymorphisms (SNPs) using MALDI mass spectrometry, termed the GOOD assay, was developed. It does not require any purification and is performed with simple liquid handling, thermal incubation and cycling steps. Although this method is well suited to automation and high-throughput analysis of SNPs, it did not allow full flexibility due to lack of certain reagents. A complete set of ss-cyanoethyl phosphoramidites is presented herein that give this SNP genotyping method full sequence and multiplex capabilities. Applications to SNP genotyping in the prion protein gene, the ss-2-adrenergic receptor gene and the angiotensin converting enzyme gene using the GOOD assay are demonstrated. Because SNP genotyping technologies are generally very sensitive to varying DNA quality, the GOOD assay has been stabilised and optimised for low quality DNA. A template extraction method is introduced that allows genotyping from tissue that was taken while placing an ear tag on an animal. This dramatically facilitates the application of genotyping to animal agricultural applications, as it demonstrates that expensive and cumbersome DNA extraction procedures prior to genotyping can be avoided.

A novel procedure for efficient genotyping of single nucleotide polymorphisms

Due to the surge in interest in using single nucleotide polymorphisms (SNPs) for genotyping a facile and affordable method for this is an absolute necessity. Here we introduce a procedure that combines an easily automatable single tube sample preparation with an efficient high throughput mass spectrometric analysis technique. Known point mutations or single nucleotide polymorphisms are easily analysed by this procedure. It starts with PCR amplification of a short stretch of genomic DNA, for example an exon of a gene containing a SNP. By shrimp alkaline phosphatase digest residual dNTPs are destroyed. Allele-specific products are generated using a special primer, a conditioned set of alpha-S-dNTPs and alpha-S-ddNTPs and a fresh DNA polymerase in a primer extension reaction. Unmodified DNA is removed by 5'-phospho-diesterase digestion and the modified products are alkylated to increase the detection sensitivity in the mass spectrometric analysis. All steps of the preparation are simple additions of solutions and incubations. The procedure operates at the lowest practical sample volumes and in contrast to other genotyping protocols with mass spectrometric detection requires no purification. This reduces the cost and makes it easy to implement. Here it is demonstrated in a version using positive ion detection on described mutations in exon 17 of the amyloid precursor protein gene and in a version using negative ion detection on three SNPs of the granulocyte-macrophage colony stimulating factor gene. Preparation and analysis of SNPs is shown separately and simultaneously, thus demonstrating the multiplexibility of this genotyping procedure. The preparation protocol for genotyping is adapted to the conditions used for the SNP discovery method by denaturing HPLC, thus demonstrating a facile link between protocols for SNP discovery and SNP genotyping. Results corresponded unanimously with the control sequencing. The procedure is useful for high throughput genotyping as it is required for gene identification and pharmacogenomics where large numbers of DNA samples have to be analysed. We have named this procedure the 'GOOD Assay' for SNP analysis.

Nucleotide sequence and genomic organization of Aleutian mink disease parvovirus (ADV): sequence comparisons between a nonpathogenic and a pathogenic strain of ADV

A DNA sequence of 4,592 nucleotides (nt) was derived for the nonpathogenic ADV-G strain of Aleutian mink disease parvovirus (ADV). The 3'(left) end of the virion strand contained a 117-nt palindrome that could assume a Y-shaped configuration similar to, but less stable than, that of other parvoviruses. The sequence obtained for the 5' end was incomplete and did not contain the 5' (right) hairpin structure but ended just after a 25-nt A + T-rich direct repeat. Features of ADV genomic organization are (i) major left (622 amino acids) and right (702 amino acids) open reading frames (ORFs) in different translational frames of the plus-sense strand, (ii) two short mid-ORFs, (iii) eight potential promoter motifs (TATA boxes), including ones at 3 and 36 map units, and (iv) six potential polyadenylation sites, including three clustered near the termination of the right ORF. Although the overall homology to other parvoviruses is less than 50%, there are short conserved amino acid regions in both major ORFs. However, two regions in the right ORF allegedly conserved among the parvoviruses were not present in ADV. At the DNA level, ADV-G is 97.5% related to the pathogenic ADV-Utah 1. A total of 22 amino acid changes were found in the right ORF; changes were found in both hydrophilic and hydrophobic regions and generally did not affect the theoretical hydropathy. However, there is a short heterogeneous region at 64 to 65 map units in which 8 out of 11 residues have diverged; this hypervariable segment may be analogous to short amino acid regions in other parvoviruses that determine host range and pathogenicity. These findings suggested that this region may harbor some of the determinants responsible for the differences in pathogenicity of ADV-G and ADV-Utah 1.

Analysis of molecularly cloned DNA reveals minor differences among three virus strains of Aleutian disease of mink parvovirus. Brief report

Molecular clones representing a 1.55 kbp genomic segment from three strains of Aleutian disease parvovirus (ADV) were studied. All three clones directed synthesis of viral structural antigens. In addition, 19 of 23 restriction sites were shared among viruses.

Identification of scrapie prion protein-specific mRNA in scrapie-infected and uninfected brain

To date no nucleic acid has been found in the purified infectious agent which causes the spongiform encephalopathy known as scrapie. In an attempt to identify a unique scrapie virus-associated messenger RNA in tissues of infected animals, we have synthesized an oligonucleotide probe complementary to the mRNA sequence corresponding to the amino-acid sequence of the prion protein, PrP27-30 (ref. 1). We report here that, with this probe, a complementary DNA clone representing PrP27-30 was obtained from scrapie-infected mouse brain; the DNA sequence of this clone could be translated into a protein that matches exactly the published sequence of PrP27-30. The cDNA clone hybridized to a single 2.4-2.5-kilobase (kb) mRNA from both normal and scrapie-infected brain. Thus, the PrP27-30 mRNA is not uniquely associated with scrapie infectivity, suggesting that PrP27-30 may be a normal component of mouse and hamster brain.

Retrolental fibroplasia and factors influencing oxygen transport

The hospital records of 58 premature infants in whom proliferative retrolental fibroplasia (RLF) developed were matched with the records of 58 infants without RLF for birth weight, gestational age, and duration oxygen therapy. The two groups were compared for factors likely to influence tissue delivery of oxygen by blood. No significant difference was found in incidence of blood transfusions or exchange transfusions, use of phototherapy, or occurrence of acidosis.