Mouse MOV10L1 associates with Piwi proteins and is an essential component of the Piwi-interacting RNA (piRNA) pathway

Piwi-interacting RNAs (piRNAs) are essential for silencing of transposable elements in the germline, but their biogenesis is poorly understood. Here we demonstrate that MOV10L1, a germ cell–specific putative RNA helicase, is associated with Piwi proteins. Genetic disruption of the MOV10L1 RNA helicase domain in mice renders both MILI and MIWI2 devoid of piRNAs. Absence of a functional piRNA pathway in Mov10l1 mutant testes causes loss of DNA methylation and subsequent derepression of retrotransposons in germ cells. The Mov10l1 mutant males are sterile owing to complete meiotic arrest. This mouse mutant expresses Piwi proteins but lacks piRNAs, suggesting that MOV10L1 is required for piRNA biogenesis and/or loading to Piwi proteins.     

Characteristics of Achromobacter xylosoxidans bacteremia in northern Taiwan.

There were 40 cases of Achromobacter xylosoxidans bacteremia during a 6-year period in a medical center in northern Taiwan. Males outnumbered females (72.5% vs 27.5%). Common underlying diseases and conditions in these 40 bacteremic patients were malignancies (57.5%), central venous catheter implants (55%), surgery (35%), neutropenia (30%) and use of steroids (25%). Recurrent bacteremia occurred in 4 patients (10%), all of whom had a central venous catheter implant which was considered the most probable source of infection. More than one-quarter (27.5%) of the cases were community acquired. The mortality rate due to A. xylosoxidans bacteremia was 47.5%. Risk factors significantly associated with mortality were nosocomial acquisition and polymicrobial bacteremia. Disk susceptibility testing showed that these isolates were resistant to aminoglycosides and most cephalosporins but were susceptible to piperacillin, imipenem, ceftazidime and trimethoprim-sulfamethoxazole.     

Identification and quantification of oligogenic loss-of-function disorders

PurposeMonogenic disorders can present clinically heterogeneous symptoms. We hypothesized that in patients with a monogenic disorder caused by a large deletion, frequently additional loss-of-function (LOF)-intolerant genes are affected, potentially contributing to the phenotype.MethodsWe investigated the LOF-intolerant gene distribution across the genome and its association with benign population and pathogenic classified deletions from individuals with presumably monogenic disorders. For people with presumably monogenic epilepsy, we compared Human Phenotype Ontology terms in people with large and small deletions.ResultsWe identified LOF-intolerant gene dense regions that were enriched for ClinVar and depleted for population copy number variants. Analysis of data from >143,000 individuals with a suspected monogenic disorder showed that 2.5% of haploinsufficiency disorder–associated deletions can affect at least 1 other LOF-intolerant gene. Focusing on epilepsy, we observed that 13.1% of pathogenic and likely pathogenic ClinVar deletions <3 megabase pair, covering the diagnostically most relevant genes, affected at least 1 additional LOF-intolerant gene. Those patients have potentially more complex phenotypes with increasing deletion size.ConclusionWe could systematically show that large deletions frequently affected admditional LOF-intolerant genes in addition to the established disease gene. Further research is needed to understand how additional potential disease-relevant genes influence monogenic disorders to improve clinical care and the efficacy of targeted therapies.     

Chicken single-chain variable fragments against the SARS-CoV spike protein

The major concern for severe acute respiratory syndrome (SARS), caused by the SARS-associated coronavirus (SARS-CoV), is the lack of diagnostic and therapeutic agents. Using a phage display technology in a chicken system, high-affinity monoclonal antibody fragments against the SARS-CoV spike protein were characterized. Ten truncated spike protein gene fragments were expressed in Escherichia coli cells. Following the immunization of chickens with these recombinant spike proteins, two single-chain variable fragment (scFv) antibody libraries were established with short or long linkers to contain 5x10(7) and 9x10(6) transformants, respectively. After four rounds of panning selection, the scFv antibodies of randomly chosen clones were demonstrated by Coomassie blue staining, and verified by western blot analysis. In a comparison of nucleotide sequences with the chicken germline gene, we found that all clones varied in the complementarity-determining regions, that two scFv antibodies reacted significantly with SARS-CoV-infected Vero cells, and that those two specific scFv antibodies recognized the same region of the spike protein spanning amino acid residues 750-1000. In conclusion, the results suggest that the chicken scFv phage display system can be a potential model for mass production of high-affinity antibodies against the SARS-CoV spike protein.     

Choroidal neovascularisation secondary to Best’s disease in a 13-year-old boy treated by intravitreal bevacizumab

Background To describe the effect of intravitreal bevacizumab for the treatment of choroidal neovascularisation secondary to vitelliform dystrophy of the macula (Best’s disease). Methods A 13-year-old boy with confirmed Best’s disease presented with visual acuity (VA) loss due to secondary choroidal neovascularisation (CNV). He was treated with a single injection of 1-mg bevacizumab. Results Best corrected VA (Snellen) fully recovered from 20/40 preoperatively to 20/20 over a period of 6 months. Optical coherence tomography (OCT) and angiography demonstrated regression of the CNV and resolution of the macular edema. Conclusions A single intravitreal injection of bevacizumab may be effective to induce morphologic and functional improvement in a juvenile suffering from CNV secondary to Best’s disease. Proprietary interest: none for all authors     

Primary closure versus radial forearm flap reconstruction after hemiglossectomy: functional assessment of swallowing and speech

The authors compared the postoperative speech and swallowing function of six patients who underwent free radial forearm flap reconstruction after hemiglossectomy with that of six control patients who underwent primary closure of the defect. Clinical speech pathologic evaluations included the Fletcher time-to-time maximum repetition rate of syllables, multiple rhyme test, and overall quality and intelligibility of the patients' speech. Evaluation of swallowing included the duration of deglutition, bolus volume, and ingestion rate. Speech quality, including intelligibility and articulation, was better in patients with primary closure. However, the bolus volume and ingestion rate in deglutition were better in those with flap reconstruction. These results suggest that the flap adds bulk, thus improving pharyngeal clearance by maintaining the tongue-to-mouth roof contact that is necessary in the swallowing process. The nonfunctional flap, however, hinders articulation by restricting the mobility of the remaining portion of the normal tongue.     

Hypoglossal schwannoma in the submandibular space

Most schwannomas of the hypoglossal nerve originate from the intracranial portion, but they may extend extracranially. Solitary and extracranial schwannomas are extremely rare. We report a case of submandibular hypoglossal schwannoma along with its clinical course and management.     

Efficacy and safety of losartan in patients with proteinuria

The renoprotective effect and safety of an angiotensin II receptor blocker, losartan, were studied in 11 diabetic and 14 nondiabetic patients with a daily urinary protein excretion >500 mg. Once-daily losartan was administered to all patients for 16 weeks without diuretics or other antihypertensive agents. A daily dose of 50 mg was given to those patients with a sitting systolic blood pressure of between 130 and 170 mm Hg; 25 mg was given to patients with a systolic blood pressure of between 110 and 130 mm Hg. Sixteen patients (6 diabetic and 10 nondiabetic patients) had a more than 25% decrease of their daily urinary protein excretion (response rate 64%). The mean decrease in these 16 patients was 57 +/- 17% (p < 0.05). Two patients (1 diabetic and 1 nondiabetic) had more than a 25% increase of their urinary protein excretion. The trough sitting systolic blood pressure of all patients (n = 25) decreased from 142 +/- 17 to 125 +/- 13 mm Hg (p < 0.05) and the trough sitting diastolic blood pressure from 87 +/- 11 to 78 +/- 11 mm Hg (p < 0.05). Serum uric acid was measured in 16 patients; a decrease from 7.3 +/- 1.6 to 6.6 +/- 1.4 mg/dl (a 9.6% decrease, p < 0.05) was found after 16 weeks. Our study showed that in both diabetic and nondiabetic proteinuric patients once-daily losartan, given as monotherapy at doses of 25 or 50 mg, was effective in reducing blood pressure, serum uric acid levels, and daily urinary protein excretions.     

Body fat standards and individual physical readiness in a randomized Army sample: screening weights,methods of fat assessment,and linkage to physical fitness

Body fat standards have been used by the military services since the early 1980s to prevent obesity and motivate good fitness habits. The Army Weight Control Program has continued to undergo evaluation and incorporate improvements based on emerging scientific findings. Recently drafted revisions of Department of Defense-wide procedures address issues of consistency and validity raised by external oversight groups. This study evaluated the impact of three proposed refinements of the Army Weight Control Program. Anthropometric measurements and fitness test performance were obtained in a randomized sample of 1,038 male and 347 nonpregnant female soldiers at three Army posts. Of this sample, 11% of men and 17% of women were overweight and overfat; 6.3 and 9.8%, respectively, were currently on the Army Weight Control Program. Screening weight tables that ensure women are not inappropriately striving to meet weights more stringent than "healthy" weight (i.e., body mass index < 25 kg/m2) still correctly identified all women for evaluation for the age-specific body fat standards. Body fat estimation using more valid DoD body fat equations that include an abdominal circumference for women reduced the number of female soldiers currently classified as exceeding fat standards, coincidentally resulting in a comparable prevalence of male and female soldiers over the fat standards (12%). A body fat allowance for young soldiers who scored very well on the physical fitness test could have benefited one-fourth of the soldiers exceeding fat standards and acknowledges biological variability in body fat thresholds. Whereas this linkage may motivate fitness habits, it complicates enforcement of reasonably achievable body fat standards. The proposed changes in fat screening and measurement methods are appropriate, but the impact to health and physical readiness of the Force cannot be accurately predicted or measured because of the absence of comprehensive baseline data and tracking mechanisms.     

Anti-tumour activity and toxicity of the new prodrug 9-aminocamptothecin glucuronide (9ACG) in mice

Cancer chemotherapy is limited by the modest therapeutic index of most antineoplastic drugs. Some glucuronide prodrugs may display selective anti-tumour activity against tumours that accumulate beta-glucuronidase. We examined the toxicity and anti-tumour activity of 9-aminocamptothecin glucuronide, a new glucuronide prodrug of 9-aminocamptothecin, to evaluate its potential clinical utility. 9-aminocamptothecin glucuronide was 25-60 times less toxic than 9-aminocamptothecin to five human cancer cell lines. Beta-glucuronidase activated 9-aminocamptothecin glucuronide to produce similar cell killing as 9-aminocamptothecin or topotecan. The in vivo toxicity of 9-aminocamptothecin glucuronide in BALB/c mice was dose-, route-, sex- and age-dependent. 9-aminocamptothecin glucuronide was significantly less toxic to female than to male mice but the difference decreased with age. 9-aminocamptothecin glucuronide and 9-aminocamptothecin produced similar inhibition (approximately 80%) of LS174T human colorectal carcinoma tumours. 9-aminocamptothecin glucuronide cured a high percentage of CL1-5 human lung cancer xenografts with efficacy that was similar to or greater than 9-aminocamptothecin, irinotecan and topotecan. The potent anti-tumour activity of 9-aminocamptothecin glucuronide suggests that this prodrug should be further evaluated for cancer treatment.