Analysis of parent of origin specific DNA methylation at SNRPN and PW71 in tissues: implication for prenatal diagnosis.

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are distinct developmental disorders caused by absence of paternal or maternal contributions of the chromosome region 15q11-q13, resulting from deletions, uniparental disomy (UPD), or rare imprinting mutations. Molecular cytogenetic diagnosis is currently performed using a combination of fluorescence in situ hybridisation (FISH), DNA polymorphism analysis, and DNA methylation analysis. Only methylation analysis will detect all three categories of PWS abnormalities, but its reliability in tissues other than peripheral blood has not been examined extensively. Therefore, we examined the methylation status at the CpG island of the small nuclear ribonucleoprotein associated polypeptide N (SNRPN) gene and at the PW71 locus using normal and abnormal lymphoblast (LB) cell lines (n = 48), amniotic fluid (AF) cell cultures (n = 25), cultured chorionic villus samples (CVS, n = 17), and fetal tissues (n = 18) by Southern blot analysis with methylation sensitive enzymes. Of these samples, 20 LB cell lines, three AF cultures, one CVS, and 15 fetal tissues had been previously diagnosed as having deletions or UPD by other molecular methods. Methylation status at SNRPN showed consistent results when compared with FISH or DNA polymorphism analysis using all cell types tested. However, the methylation pattern for PW71 was inconsistent when compared with other tests and should therefore not be used on tissues other than peripheral blood. We conclude that SNRPN, but not PW71, methylation analysis may be useful for diagnosis of PWS/AS on LB cell lines, cultured amniotic fluid, or chorionic villus samples and will allow, for the first time, prenatal diagnosis for families known to carry imprinting centre defects.     

Endobronchial radiation therapy for obstructing malignancies: Ten years' experience with iridium-192 high-dose radiation brachytherapy afterloading technique in 365 patients

From 1983 to 1993, 365 patients with obstructing endobronchial malignancies were treated by endobronchial high-dose radiation (HDR) iridium-192 afterloading. In 346 patients, the objective was palliation, and in 19, the objective was curative. A dose of 5 Gy at 10 mm from the source axis was administered on three (palliation) and four (cure) occasions, at intervals of 14 days. The majority of patients were treated after exhaustion of external beam radiation therapy (EBRT), often in conjunction with other interventional bronchologic modalities such as endobronchial laser resection. Of the patients, 65% had a squamous cell carcinoma. Endobronchial HDR brachytherapy results in few acute complications and can be performed with no major discomfort on an outpatient basis. In approximately 66% of patients, a palliative effect is achieved, even after the exhaustion of conventional treatment. Life may be prolonged for a few months, but the enhancement of survival is difficult to assess for several reasons. Mean survival is 9 months for limited disease and 5 months for extensive disease. Endobronchial HDR brachytherapy influences the pattern of failure: a 21% rate of fatal hemorrhages is probably the result of the selection of patients for this treatment rather than a treatment-related complication. There is sufficient evidence to suggest the rational use of HDR brachytherapy in combination with EBRT to effect a cure, or even on its own when tumor growth is strictly limited. However, the standardization of radiotherapy and endoscopic indications is an urgent priority. Prospective, controlled, and cooperative studies are mandatory. Endobronchial iridium-192 HDR brachytherapy complements endobronchial laser resection and is currently an established technique in the treatment of advanced malignant airway obstructions.Offprint requests to: Priv. Doz. Dr H.-N. Macha     

Vaccination of rhesus macaques with a recombinant measles virus expressing interleukin-12 alters humoral and cellular immune responses

Lack of a vaccine for infants and immunosuppression after infection are problems associated with measles virus (MV). Because interleukin (IL)-12 has been used successfully as a vaccine adjuvant and because inhibition of IL-12 expression has been associated with immunosuppression during measles, the addition of IL-12 may enhance the immune response to MV. To determine the effect of IL-12 supplementation, rhesus macaques were vaccinated with a recombinant MV expressing IL-12; these macaques had increased interferon-gamma production by CD4(+) T cells, decreased production of IL-4, and lower levels of MV-specific immunoglobulin G4 and neutralizing antibody. Lymphoproliferative responses to mitogen were not improved. IL-12 supplementation altered the T helper type 2 bias of the immune response after MV vaccination, had a detrimental effect on the protective neutralizing antibody response, and did not improve other manifestations of immunosuppression. Reduced IL-12 levels are not the sole factor in MV-induced immunosuppression.     

Effect of Gemfibrozil,Rifampicin, or Probenecid on the Pharmacokinetics of the SGLT2 Inhibitor Empagliflozin in Healthy Volunteers

Background

Empagliflozin is a potent, oral, selective inhibitor of sodium glucose cotransporter 2 in development for the treatment of type 2 diabetes mellitus.

Objective

The goal of these studies was to investigate potential drug–drug interactions between empagliflozin and gemfibrozil (an organic anion-transporting polypeptide 1B1 [OATP1B1]/1B3 and organic anion transporter 3 [OAT3] inhibitor), rifampicin (an OATP1B1/1B3 inhibitor), or probenecid (an OAT3 and uridine diphosphate glucuronosyltransferase inhibitor).

Methods

Two open-label, randomized, crossover studies were undertaken in healthy subjects. In the first study, 18 subjects received the following in 1 of 2 randomized treatment sequences: a single dose of empagliflozin 25 mg alone and gemfibrozil 600 mg BID for 5 days with a single dose of empagliflozin 25 mg on the third day. In the second study, 18 subjects received a single dose of empagliflozin 10 mg, a single dose of empagliflozin 10 mg coadministered with a single dose of rifampicin 600 mg, and probenecid 500 mg BID for 4 days with a single dose of empagliflozin 10 mg on the second day in 1 of 6 randomized treatment sequences.

Results

In the gemfibrozil study, 11 subjects were male, mean age was 35.1 years and mean body mass index (BMI) was 23.47 kg/m². In the rifampicin/probenecid study, 10 subjects were male, mean age was 32.7 years and mean BMI was 23.03 kg/m². Exposure to empagliflozin was increased by coadministration with gemfibrozil (AUC_0–∞: geometric mean ratio [GMR], 158.50% [90% CI, 151.77–165.53]; C_max: GMR, 115.00% [90% CI, 106.15–124.59]), rifampicin (AUC_0–∞: GMR, 135.20% [90% CI, 129.58–141.06]; C_max: GMR, 175.14% [90% CI, 160.14–191.56]), and probenecid (AUC_0–∞: GMR, 153.47% [90% CI, 146.41–160.88]; C_max: GMR, 125.60% [90% CI, 113.67–138.78]). All treatments were well tolerated.

Conclusions

Increases in empagliflozin exposure were <2-fold, indicating that the inhibition of the OATP1B1/1B3, OAT3 transporter, and uridine diphosphate glucuronosyltransferases did not have a clinically relevant effect on empagliflozin exposure. No dose adjustments of empagliflozin were necessary when it was coadministered with gemfibrozil, rifampicin, or probenecid. ClinicalTrials.gov identifiers: NCT01301742 and NCT01634100.     

Accelerated 3D MERGE carotid imaging using compressed sensing with a hidden markov tree model

Purpose:

To determine the potential for accelerated 3D carotid magnetic resonance imaging (MRI) using wavelet based compressed sensing (CS) with a hidden Markov tree (HMT) model.

Materials and Methods:

We retrospectively applied HMT model‐based CS and conventional CS to 3D carotid MRI data with 0.7 mm isotropic resolution from six subjects with known carotid stenosis (12 carotids). We applied a wavelet‐tree model learned from a training database of carotid images to improve CS reconstruction. Quantitative endpoints such as lumen area, wall area, mean and maximum wall thickness, plaque calcification, and necrotic core area were measured and compared using Bland–Altman analysis along with image quality.

Results:

Rate‐4.5 acceleration with HMT model‐based CS provided image quality comparable to that of rate‐3 acceleration with conventional CS and fully sampled reference reconstructions. Morphological measurements made on rate‐4.5 HMT model‐based CS reconstructions were in good agreement with measurements made on fully sampled reference images. There was no significant bias or correlation between mean and difference of measurements when comparing rate 4.5 HMT model‐based CS with fully sampled reference images.

Conclusion:

HMT model‐based CS can potentially be used to accelerate clinical carotid MRI by a factor of 4.5 without impacting diagnostic quality or quantitative endpoints. J. Magn. Reson. Imaging 2012;36:1194–1202. © 2012 Wiley Periodicals, Inc.