2,840 research outputs found
Acceleration of generalized hypergeometric functions through precise remainder asymptotics
We express the asymptotics of the remainders of the partial sums {s_n} of the
generalized hypergeometric function q+1_F_q through an inverse power series z^n
n^l \sum_k c_k/n^k, where the exponent l and the asymptotic coefficients {c_k}
may be recursively computed to any desired order from the hypergeometric
parameters and argument. From this we derive a new series acceleration
technique that can be applied to any such function, even with complex
parameters and at the branch point z=1. For moderate parameters (up to
approximately ten) a C implementation at fixed precision is very effective at
computing these functions; for larger parameters an implementation in higher
than machine precision would be needed. Even for larger parameters, however,
our C implementation is able to correctly determine whether or not it has
converged; and when it converges, its estimate of its error is accurate.Comment: 36 pages, 6 figures, LaTeX2e. Fixed sign error in Eq. (2.28), added
several references, added comparison to other methods, and added discussion
of recursion stabilit
Impact of hormonal therapy on the detection of promoter hypermethylation of the detoxifying glutathione-S-transferase P1 gene (GSTP1) in prostate cancer
BACKGROUND: In spite of excellent cure rates for prostate cancer patients with favorable tumor characteristics, patients with unfavorable characteristics after radical prostatectomy are still at a significantly increased risk of tumor progression. Early adjuvant hormonal therapy (AHT) has been shown to be of prognostic benefit in these patients. Unfortunately initiation and duration of early AHT in the individual patient is based on statistic data. PSA, as the standard prostate marker is neither able to reliably indicate minimal residual tumor disease in the early postoperative phase, nor can it be used for therapy monitoring due to the suppressive effect of hormonal therapy on PSA production. Promoter hypermethylation of the detoxifying glutathione-S-transferase P1 gene (GSTP1-HM) has been shown to be the most common DNA alteration of primary prostatic carcinoma which, when used as a marker, is supposed to be able to overcome some of the disadvantages of PSA. However until now information on the impact of hormonal therapy on the detection of GSTP1-HM is lacking. The purpose of our study was to assess the impact of endocrine therapy on the detection of GSTP1-HM by methylation-specific PCR (MSP) in prostate cancer. METHODS: Paraffin embedded tumor samples from the radical prostatectomy (RP) specimens from 15 patients after hormonal therapy (HT) (mean 8 months) were assessed by MSP. In 8 of the patients the GSTP-1 status of the tumors before HT was assessed on the corresponding initial diagnostic biopsies. RESULTS: Following HT MSP showed GSTP1-HM in 13/15 of the RP specimens. In two patients analysis of the RP specimens failed to show GSTP1-HM. All initial tumor samples (8/8 biopsy specimens) showed GSTP1-HM, including both patients negative for GSTP1 HM in the corresponding RP specimen. CONCLUSION: In most cases hormonal therapy appears to not alter GSTP1 HM detection. However the change from a positive to a negative GSTP1 HM status in a subset of the patients may point to an, at least partial androgen dependency. Further studies on a larger cohort of patients are necessary to assess its frequency and the exact hormonal interactions
Catheter Balloon Adjustment of the Pulmonary Artery Band: Feasibility and Safety
The study aimed to assess the feasibility and safety of increasing pulmonary artery band (PAB) diameter by catheter-based PAB balloon dilation (PABBD). Eight dilations were performed between October 2006 and December 2008. Hemoclips were used to fix PABs surgically in a procedure designed to permit progressive clip dislodgment in a controlled manner. The PABBD resulted in gradual band loosening until the desired physiologic state was achieved. At time of PABBD, the patients had a mean age of 6 months (range 3–14 months) and a mean weight of 5 kg (range 2.6–7.3 kg). The median time from PAB placement until PABBD was 4.5 months (range 1–9 months). The single-balloon technique was used in seven cases (serial dilations in 5 cases) and the double-balloon technique in one case. The PABBDs were successful for all the patients, who experienced a mean saturation increase of 75–89% (P = 0.01) (mean increase of 20%), a mean PAB gradient decrease from 69 to 36 mmHg (P = 0.002) (mean decrease of 49%), and a mean band site diameter increase from 4.1 to 6.1 mm (P = 0.01) (mean increase of 45%). The only complication was transient pulmonary edema in one patient. The PABBD procedure is a feasible and safe method for increasing pulmonary blood flow in a staged manner and may eliminate the need for surgical band removal in some cases
Sample size calculation for microarray experiments with blocked one-way design
<p>Abstract</p> <p>Background</p> <p>One of the main objectives of microarray analysis is to identify differentially expressed genes for different types of cells or treatments. Many statistical methods have been proposed to assess the treatment effects in microarray experiments.</p> <p>Results</p> <p>In this paper, we consider discovery of the genes that are differentially expressed among <it>K </it>(> 2) treatments when each set of <it>K </it>arrays consists of a block. In this case, the array data among <it>K </it>treatments tend to be correlated because of block effect. We propose to use the blocked one-way ANOVA <it>F</it>-statistic to test if each gene is differentially expressed among <it>K </it>treatments. The marginal p-values are calculated using a permutation method accounting for the block effect, adjusting for the multiplicity of the testing procedure by controlling the false discovery rate (FDR). We propose a sample size calculation method for microarray experiments with a blocked one-way design. With FDR level and effect sizes of genes specified, our formula provides a sample size for a given number of true discoveries.</p> <p>Conclusion</p> <p>The calculated sample size is shown via simulations to provide an accurate number of true discoveries while controlling the FDR at the desired level.</p
Trans-Epithelial Immune Cell Transfer during Suckling Modulates Delayed-Type Hypersensitivity in Recipients as a Function of Gender
INTRODUCTION: Breast feeding has long term effects on the developing immune system which outlive passive immunization of the neonate. We have investigated the transfer of milk immune cells and examined the result of transfer once the recipients were adult. METHODS: Non-transgenic mouse pups were foster-nursed by green fluorescent protein (GFP) transgenic dams for 3 weeks and the fate of GFP+ cells was followed by FACS analysis, immunohistochemistry and RT-PCR for GFP and appropriate immune cell markers. Pups suckled by non-transgenic dams served as controls. RESULTS: Despite a preponderance of B cells and macrophages in the stomach contents of the pups, most cells undergoing trans-epithelial migration derived from the 3-4% of milk cells positive for T lymphocyte markers. These cells homed to the spleen and thymus, with maximal accumulation at 3-4 weeks. By sensitizing dams with an antigen which elicits a T cell-mediated delayed-type-hypersensitivity (DTH) response, we determined that nursing by a sensitized dam (compared to a non-sensitized dam) amplified a subsequent DTH response in females and yet suppressed one in males. DISCUSSION: These results suggest that clinical evaluation weighing the pros and cons of nursing male versus female children by mothers with genetically-linked hypersensitivity diseases, such as celiac disease and eczema, or those in regions of the world with endemic DTH-eliciting diseases, such as tuberculosis, may be warranted
A retrospective study on IVF outcome in euthyroid patients with anti-thyroid antibodies: effects of levothyroxine, acetyl-salicylic acid and prednisolone adjuvant treatments
<p>Abstract</p> <p>Background</p> <p>Anti-thyroid antibodies (ATA), even if not associated with thyroid dysfunction, are suspected to cause poorer outcome of in vitro fertilization (IVF).</p> <p>Methods</p> <p>We retrospectively analyzed: (a) the prevalence of ATA in euthyroid infertile women, (b) IVF outcome in euthyroid, ATA+ patients, and (c) the effect of adjuvant treatments (levothyroxine alone or associated with acetylsalicylic acid and prednisolone) on IVF results in ATA+ patients. One hundred twenty-nine euthyroid, ATA+ women undergoing IVF were compared with 200 matched, ATA-controls. During IVF cycle, 38 ATA+ patients did not take any adjuvant treatment, 55 received levothyroxin (LT), and 38 received LT +acetylsalicylic acid (ASA)+prednisolone (P).</p> <p>Results</p> <p>The prevalence of ATA among euthyroid, infertile patients was 10.5%, similar to the one reported in euthyroid women between 18 and 45 years. ATA+ patients who did not receive any adjuvant treatment showed significantly poorer ovarian responsiveness to stimulation and IVF results than controls. ATA+ patients receiving LT responded better to ovarian stimulation, but had IVF results as poor as untreated ATA+ women. Patients receiving LT+ASA+P had significantly higher pregnancy and implantation rates than untreated ATA+ patients (PR/ET 25.6% and IR 17.7% vs. PR/ET 7.5% and IR 4.7%, respectively), and overall IVF results comparable to patients without ATA (PR/ET 32.8% and IR 19%).</p> <p>Conclusion</p> <p>These observations suggest that euthyroid ATA+ patients undergoing IVF could have better outcome if given LT+ASA+P as adjuvant treatment. This hypothesis must be verified in further randomized, prospective studies.</p
Left main bronchus resection and reconstruction. A single institution experience
<p>Abstract</p> <p>Background</p> <p>Left main bronchus resection and reconstruction (LMBRR) is a complex surgical procedure indicated for management of inflammatory, benign and low grade malignant lesions. Its application provides maximal parenchymal sparing.</p> <p>Methods</p> <p>Out of 98 bronchoplastic procedures performed at the Authors' Institution in the 1995-2011 period, 4 were LMBRR. Indications were bronchial carcinoid in 2 cases, inflammatory pseudotumor in 1 case, TBC stricture in 1 case. All patients underwent preoperatively a rigid bronchoscopy to restore the airway lumen patency. At surgery a negative resection margin was confirmed by frozen section in the neoplastic patients. In all patients an end-to-end bronchial anastomosis was constructed according to Grillo.</p> <p>Results</p> <p>There were neither mortality nor major complications. Airway lumen was optimal in 3 patients, good in 1.</p> <p>Conclusion</p> <p>LMBRR is a valuable option for the thoracic surgeon. It maximizes the parenchyma-sparing philosophy, broadening the spectrum of potential candidates for cure. It remains a technically demanding procedure, to be carried out by an experienced surgical team. Correct surgical planning affords excellent results, both in the short and long term.</p
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