Safety and long-term efficacy of transduodenal excision for tumors of the ampulla of Vater

BACKGROUND

Ampullary tumors should be resected because of the high incidence of malignancy and the unreliability of preoperative endoscopic diagnosis. Controversy exists about whether to perform a transduodenal excision (TDE) or a pancreatoduodenectomy. This study evaluated the safety and long-term efficacy of TDE.

METHODS

The records of 21 patients with a pathologic diagnosis of ampullary adenoma who underwent TDE were reviewed. Demographics, symptoms, pathologic findings, and outcomes were analyzed and long-term follow-up was ascertained.

RESULTS

Twenty-one patients (mean age, 61 years) underwent TDE. Final pathology showed adenoma in all patients including 1 (5%) with invasive cancer, 2 (9%) with microinvasive cancer, 6 (28%) with high-grade dysplasia, and 1 (5%) with low-grade dysplasia. The overall survival was 85% (mean follow-up of 38 months). One of 3 late deaths was likely related to disease progression. Sixteen of the 18 remaining patients (89%) had no evidence of tumor recurrence. One benign ampullary recurrence was successfully treated endoscopically. One additional patient developed an ampullary cancer and underwent pancreatoduodenectomy.

CONCLUSIONS

TDE of benign ampullary tumors, even those with varying grades of dysplasia, can be performed with acceptable morbidity and low rates of recurrence. Postoperative endoscopic surveillance is mandatory to identify recurrent tumors.

Linearity and the limitations of least squares calibration

The magnitude of errors that can arise in practice from the limitations of the least squares method of calibration is estimated. Data generated from y = xn (0.7 < or = n < or = 1.3 and 1 < or = x < or = 30, or < or = 60) was analysed by least squares regression. Each y-value was then presented to the linear model and an x-value predicted. The relative errors on small x-values reached 70% of the concentration value even when r2 exceeded 0.999. Estimates of the errors on each predicted x-value, determined from the standard errors of the slope and intercept failed to reveal large errors at small x-values. Reducing the range over which linear regression is performed improved the errors. Other data sets with a heteroscedastic error distribution show that linear regression by least squares can also lead to the rejection of methods that performed sufficiently well for their application. Heteroscedastic data may be treated by repeated measurements at the lower end of the range. Data from a validation of an HPLC method for isoflavones in legumes is used to show the errors in recovery when a check sample is presented to the instrument using a calibration which satisfies the linearity tests. It is recommended that both y- and relative x-residuals are inspected. It is proposed that over-reliance on linear calibration supported by r2 may make a major contribution to large, hitherto unexplained, inter-laboratory errors.

Full and fractionated experimental designs for robustness testing in the high-performance liquid chromatographic analysis of codeine phosphate, pseudoephedrine hydrochloride and chlorpheniramine maleate in a pharmaceutical preparation

This paper describes the testing of a saturated factorial design using a full factorial design. Saturated factorial designs are often used to test the robustness of high-performance liquid chromatography (HPLC) methods, however they are based on several assumptions. A full factorial design relies on fewer assumptions and hence could be used to evaluate the effectiveness of the saturated design. Both designs were used to test a gradient HPLC method for the assay of codeine phosphate, pseudoephedrine hydrochloride and chlorpheniramine maleate. Six HPLC conditions, including wavelength, mobile phase pH and ion pairing reagent concentration were tested using the saturated design. Three of these factors were selected for full evaluation using a full factorial design. The results showed that the main effects calculated by each design were comparable. However, the saturated design showed higher standard errors, probably due to the effects of changing several more factors. One interaction effect was indicated as a confounding effect by the saturated design and this was confirmed by the calculation of the same interaction effect using the full design. Overall the method was shown to be robust under the variety of HPLC conditions tested.

Classification of chondroitin sulfate A, chondroitin sulfate C, glucosamine hydrochloride and glucosamine 6 sulfate using chemometric techniques

Chondroitin sulfate A, chondroitin sulfate C, glucosamine hydrochloride and glucosamine sulfate are natural products that are becoming increasingly popular in the treatment of arthritis. They belong to a class of compounds known as glycosaminoglycans (GAGs). They are available over the counter as nutritional supplements. However, increasing use has led to increasing scrutiny of the quality of products on the market. There is also interest in the pharmacological properties of these compounds. To facilitate this, there is a need for better qualitative and quantitative methods of analysis. This paper describes methods for achieving the qualitative identification of chondroitin sulfate A, chondroitin sulfate C, glucosamine hydrochloride or glucosamine sulfate. Fourier transform infrared spectroscopy coupled with a variety of chemometric methods successfully classified these compounds. Using soft independent modeling of class analogies (SIMCA), hierarchical cluster analysis (HCA) and principal components analysis (PCA) samples were classified as either chondroitin sulfate A, chondroitin sulfate C, glucosamine hydrochloride or glucosamine sulfate. This work also examined the discriminating ability of different sections of the spectrum. It was found that for the classification of these compounds that using the finger print region of the spectrum (below 2000 cm(-1)) gave the best discrimination.

Neuromuscular and mechanical responses to inspiratory resistive loading during sleep

The purposes of this study were 1) to characterize the immediate inspiratory muscle and ventilation responses to inspiratory resistive loading during sleep in humans and 2) to determine whether upper airway caliber was compromised in the presence of a resistive load. Ventilation variables, chest wall, and upper airway inspiratory muscle electromyograms (EMG), and upper airway resistance were measured for two breaths immediately preceding and immediately following six applications of an inspiratory resistive load of 15 cmH2O.l-1 X s during wakefulness and stage 2 sleep. During wakefulness, chest wall inspiratory peak EMG activity increased 40 +/- 15% (SE), and inspiratory time increased 20 +/- 5%. Therefore, the rate of rise of chest wall EMG increased 14 +/- 10.9% (NS). Upper airway inspiratory muscle activity changed in an inconsistent fashion with application of the load. Tidal volume decreased 16 +/- 6%, and upper airway resistance increased 141 +/- 23% above pre-load levels. During sleep, there was no significant chest wall or upper airway inspiratory muscle or timing responses to loading. Tidal volume decreased 40 +/- 7% and upper airway resistance increased 188 +/- 52%, changes greater than those observed during wakefulness. We conclude that 1) the immediate inspiratory muscle and timing responses observed during inspiratory resistive loading in wakefulness were absent during sleep, 2) there was inadequate activation of upper airway inspiratory muscle activity to compensate for the increased upper airway inspiratory subatmospheric pressure present during loading, and 3) the alteration in upper airway mechanics during resistive loading was greater during sleep than wakefulness.

Quantitative determination of isoflavones and coumestrol in soybean by column liquid chromatography

Four different stationary phases and a variety of solvents in varying proportions were examined in this study. Daidzein, genistein, formononetin, biochanin A and coumestrol were separated within 24 min on a phenyl column with acetonitrile-water (33:67, v/v) as eluent. The proposed method showed an acceptable repeatability with a RSD of quantitation <6%. The mean recoveries of daidzein, genistein, formononetin, biochanin A and coumestrol from soybean ranged from 89 to 104%. The identity of the individual analytes was confirmed by LC-MS-MS. The four isoflavones and coumestrol were isolated from soybean by hydrolysis with acid and heat. Neutralization of the soybean samples prior to identification did not alter the concentration of daidzein and genistein in soybean.

Ghrelin contributes to derangements of glucose metabolism induced by rapamycin in mice

AIMS/HYPOTHESIS

Rapamycin impairs glucose tolerance and insulin sensitivity. Our previous study demonstrated that rapamycin significantly increases the production of gastric ghrelin, which is critical in the regulation of glucose metabolism. Here, we investigated whether ghrelin contributes to derangements of glucose metabolism induced by rapamycin.

METHODS

The effects of rapamycin on glucose metabolism were examined in mice receiving ghrelin receptor antagonist or with Ghsr1a gene knockout. Changes in GLUT4, c-Jun N-terminal kinase (JNK) and phosphorylated ribosomal protein S6 (pS6) were investigated by immunofluorescent staining or western blotting. Related hormones were detected by radioimmunoassay kits.

RESULTS

Rapamycin impaired glucose metabolism and insulin sensitivity not only in normal C57BL/6J mice but also in both obese mice induced by a high fat diet and db/db mice. This was accompanied by elevation of plasma acylated ghrelin. Rapamycin significantly increased the levels of plasma acylated ghrelin in normal C57BL/6J mice, high-fat-diet-induced obese mice and db/db mice. Elevation in plasma acylated ghrelin and derangements of glucose metabolism upon administration of rapamycin were significantly correlated. The deterioration in glucose homeostasis induced by rapamycin was blocked by D: -Lys3-GHRP-6, a ghrelin receptor antagonist, or by deletion of the Ghsr1a gene. Ghrelin receptor antagonism and Ghsr1a knockout blocked the upregulation of JNK activity and downregulation of GLUT4 levels and translocation in the gastrocnemius muscle induced by rapamycin.

CONCLUSIONS/INTERPRETATION

The current study demonstrates that ghrelin contributes to derangements of glucose metabolism induced by rapamycin via altering the content and translocation of GLUT4 in muscles.

Do research papers provide enough information on design and material used in ankle foot orthoses for children with cerebral palsy? A systematic review

OBJECTIVES

The purpose of this article is to determine how many of the current peer-reviewed studies of ankle foot or-thoses (AFOs) on children with cerebral palsy (CP) have included adequate details of the design and material of the AFO, to enable the study to be reproduced and outcomes clearly understood.

METHODS

A thorough search of studies published in English was conducted in March 2015, with no restriction on dates, within all major databases using relevant phrases. These searches were then supplemented by tracking all key references from the appropriate articles identified.

STUDY SELECTION

The inclusion criteria were as follows: (1) population - children with CP; (2) intervention - AFOs; and (3) outcome measure. One reviewer extracted data regarding the characteristics of the included studies, with the extracted data checked for accuracy and completeness by a second reviewer. None of the studies reviewed gave adequate details of the AFOs. Only 3.6% (n = 2) of papers tested the stiffness. Many studies (54.5%) did not describe the material used nor the material thickness (72.7 %). None of them gave any clinical justification for the chosen design of AFO.

CONCLUSIONS

There is a clear paucity of detail regarding the design and material used in AFOs on studies involving children with CP. Such a lack of detail has the potential to affect the validity of the reported outcomes, the ability to reproduce the studies and may misinform clinical practice.

Surgical treatment of duodenal ulcer: a prospective randomized study

From 1960 to 1980, 344 patients were included in a prospective randomized study for elective surgical treatment of duodenal ulcer disease. Results of vagotomy and pyloroplasty were compared with vagotomy and hemigastrectomy. There were no postoperative deaths, the postoperative complication rates were similar for both groups. Ulcerations recurred in 12% of the vagotomy-pyloroplasty group and in 3% of the vagotomy-hemigastrectomy group (P less than .05). Independent analyses of recurrence were performed for young patients, for alcoholics, and for patients who had obstructions or were bleeding preoperatively. Recurrence rates in these special populations were not found to be significantly different. Eight percent of the vagotomy-pyloroplasty group required reoperations for recurrent ulceration; only 2% of the vagotomy-hemigastrectomy group required reoperation. Postoperative dumping symptoms were significantly more frequent in the vagotomy hemigastrectomy group. Postoperative diarrhea was also more frequent and more severe in the vagotomy-hemigastrectomy group.

Comparison of equations describing band broadening in high-performance liquid chromatography

Several models are well established that describe band broadening in gas and liquid chromatography, including those due to Van Deemter and Knox. Comparison of competing models is complicated if raw data are noisy or if the equations to be fitted to data contain many adjustable parameters. This paper describes a comparison of fitting the Van Deemter, Knox and other equations to low noise data gathered during the separation of propyl- and methylparaben by HPLC. Equations are compared using established statistical methods, including analysis of residuals, inference of parameter estimates and Akaikes Information Criterion for model identification. This work indicates that equations that account for non-linear band broadening at elevated mobile phase velocities are more successful at describing the relationship between height equivalent to a theoretical plate, H, and the velocity of the mobile phase, u.

Direct identification and quantitation of prednisone in the presence of overlapping hydrocortisone by liquid chromatography with electrospray and atmospheric-pressure chemical-ionisation mass spectrometry

The paper describes the application of liquid chromatography interfaced to a triple quadrupole mass spectrometer utilising the multiple reaction monitoring (MRM) mode. The technique was shown to provide detection limits lower than 0.01% for the analysis of prednisone in the presence of hydrocortisone. Prednisone was mixed in concentrations from 0.500 to 0.0005 ppm (corresponding to 1% to 0.001% of the hydrocortisone concentration). These solutions were assayed using MRM observing the product ion transitions of 359.2-->147.1 and 359.2-->171.2 and was shown to be capable of detecting co-eluting impurities at concentrations of less than 0.001% of the major component. The assay of prednisone was shown to be linear over the range 0.500-0.0005 ppm with a correlation coefficient of 0.999 and a precision of 6.9% at the concentration of 0.005 ppm. The analysis was carried out using both atmospheric pressure chemical ionisation (APCI) and electrospray ionisation (ESI) as an interface. However, for these compounds APCI provided significantly more sensitive data compared to ESI.

Optimisation for the separation of the oligosaccharide, sodium Pentosan Polysulfate by reverse polarity capillary zone electrophoresis using a central composite design

The separation by reverse polarity capillary zone electrophoresis of the therapeutically developed sodium salt of Pentosan Polysulfate was optimised through the analysis of response surface methodologies, modeled using a central composite design. The optimisation investigated injection pressure, injection time and voltage and the effect of the conditions on retention times, peak areas, separation efficiency and the method sensitivity. The overall goal was to develop the most sensitive results with no decrease in separation efficiency. The following results were obtained: (1) retention times generally decreased as injection pressure, injection time and voltage increased, injection time having the least effect; (2) as expected peak areas increased as injection pressure and injection time increased but decreased as voltage increased; (3) separation efficiencies generally increased as injection pressure and injection time decreased, with voltage having almost no effect. For the optimum condition, the sample was introduced at the inlet vial at the cathode hydrodynamically, at optimal setting of 44 s at 35 mbar. The optimal voltage was -20 kV. In comparison with other methods, the optimum showed increased sensitivity, resolution and separation efficiency. Repeatability studies were performed on the optimum parameter conditions. Relative standard deviation values obtained were between 0.9 and 5.4%.

The levonorgestrel intra-uterine system: therapeutic application in family planning

OBJECTIVE

To assess the non-contraceptive benefits of the levonorgestrel intra-uterine system 12 months following insertion in a family planning setting.

DESIGN

Postal questionnaire survey.

SETTING

Family planning clinics at the Ulster and Bangor Hospitals.

SUBJECTS

Eighty-six consecutive subjects fitted with the levonorgestrel intra-uterine system.

RESULTS

Response rate 87.3%. Outcome measured in terms of compliance, satisfaction and menstrual symptomatology. Reasons for insertion were as follows: 21.7% contraception only; 65.2% menorrhagia, 24.6% dysmenorrhoea and 1.4% premenstrual syndrome. Duration of menses was 8.25 days pre-insertion and 2.41 days at 12 months. Of the subjects, 59.4% experienced at least one hormonal side effect; 10.1% of systems were removed within 12 months. At 12 months 86.9% of women were satisfied and 9.8% of women planned to discontinue.

CONCLUSION

The levonorgestrel intra-uterine system was acceptable to almost 80% of women after 12 months, with significant reduction in duration of menses. Family planning clinics are an ideal setting to implement the guidelines for the initial management of menorrhagia.