Determination of the refractive index and thickness of a hydroxide-catalysis bond between fused silica from reflectivity measurements

Hydroxide-catalysis bonding is a high precision jointing technique producing strong, transparent and thin bonds, the use of which in the delicate fused silica mirror suspensions of aLIGO have been instrumental in the first detections of gravitational radiation. More sensitive future gravitational wave detectors will require more accurate (ideally in situ) measurements of properties such as bond thickness. Here a non-destructive technique is presented in which the thickness and refractive index of a bond are determined from measurements of optical reflectivity. The reflectivity of a bond made between two fused silica discs using sodium silicate solution is less than 1⋅10^-3 after 3 months. The thickness decreases to a constant value of around 140 nm at its minimum and the refractive index increases from 1.36 to 1.45. This proves that as well as determination of bond thickness in situ this bonding technique is highly interesting for optical applications.

Spatiotemporal accuracy of real-time 3D echocardiography in the neonatal and pediatric setting--validation studies using small dynamic test objects

The precision of real-time 3D-echocardiography (RT3DE) is not sufficiently validated for small, fast-moving structures such as the neonatal and pediatric heart.

PURPOSE

To assess the spatiotemporal accuracy of RT3DE in small, moving test objects.

MATERIALS AND METHODS

Small, calibrated test objects in the size of neonatal and pediatric heart chambers were made from polyurethane foam or metal wire mesh and moved in a water bath through a calibrated dynamic test system. Using matrix transducers (X7-2, ie33 and X4-1, Sonos 7500, Philips, Andover, USA), 2 D and live 3 D datasets under variation of the motion speed (0.033 - 0.133 m/s corresponding to 50 - 200 heart cycles/minute), the volume rate and transducer position were recorded and analyzed (QLab 7.0, Philips).

RESULTS

3 D datasets of the moving test objects showed relevant spatial distortion, which was obviously related to the sequential scanning technology of the matrix transducer. Different segments of a test object were not recorded simultaneously, but rather row-by-row, so that there was a time delay between the first and the last-recorded voxel of a single 3 D volume (mean±SD: 28.9 ± 7.82 m/s or 80 ± 7 % of the time duration of a 3 D volume). With increasing motion speed of the test object and reduced 3 D volume rate, the distortion artifacts increased significantly.

CONCLUSION

3 D acquisitions using matrix technology demonstrate relevant spatiotemporal inaccuracies. This may lead to misinterpretations during the evaluation of the synchronicity of valvular or ventricular motion and incorrect definition of volume estimations. In particular, at higher heart rates and higher rates of movement, these limitations have to be taken into account in clinical practice.

Prototype of an auto-calibrating, context-aware, hybrid brain-computer interface

We present the prototype of a context-aware framework that allows users to control smart home devices and to access internet services via a Hybrid BCI system of an auto-calibrating sensorimotor rhythm (SMR) based BCI and another assistive device (Integra Mouse mouth joystick). While there is extensive literature that describes the merit of Hybrid BCIs, auto-calibrating and co-adaptive ERD BCI training paradigms, specialized BCI user interfaces, context-awareness and smart home control, there is up to now, no system that includes all these concepts in one integrated easy-to-use framework that can truly benefit individuals with severe functional disabilities by increasing independence and social inclusion. Here we integrate all these technologies in a prototype framework that does not require expert knowledge or excess time for calibration. In a first pilot-study, 3 healthy volunteers successfully operated the system using input signals from an ERD BCI and an Integra Mouse and reached average positive predictive values (PPV) of 72 and 98% respectively. Based on what we learned here we are planning to improve the system for a test with a larger number of healthy volunteers so we can soon bring the system to benefit individuals with severe functional disability.

Impact of Newly Available Drugs on Clinical Progression in Patients with Virological Failure after Exposure to Three Classes of Antiretrovirals

Objective

To study the prognosis of HIV-infected patients with virological failure after exposure to three classes of antiretroviral drugs (ARVs).

Design

Cohort study. Setting: French Hospital Database on HIV.

Patients

Patients previously exposed to at least two nucleoside reverse transcriptase inhibitors (NRTIs), two protease inhibitors and one non-NRTI, with viral load (VL) values of >5000 copies/ml after the exposure criteria were met and a new treatment initiated between 1998 and 2001 with VL >5000 copies/ml.

Main outcome measures

Risk of new AIDS-defining-events (ADEs) or death from first introduction of a drug never used before occurring between 1998 and 2001 defined as baseline.

Results

The main baseline characteristics of the 1092 patients were: previous ADE in 49% of cases, median CD4 cell count 181 μl, median VL 4.9 log10 copies/ml, median duration of ARV therapy 5.0 years and previous exposure to a median of nine ARVs. The crude progression rates were 20.1/100 patient-years among patients included in 1998, 15.1 in 1999, 11.1 in 2000 and 8.6 in 2001. After adjustment for baseline characteristics, the calendar year of inclusion was associated with the risk of clinical progression ( P<0.001). When the types of newly available drugs used at baseline or during follow-up were introduced into the model, year of inclusion was no longer associated with the risk of clinical progression ( P=0.42), while exposure to amprenavir/r, lopinavir/r, abacavir or tenofovir was associated with a lower risk.

Conclusions

The clinical prognosis of heavily pretreated patients experiencing virological failure improved between 1998 and 2001, mainly thanks to the use of newly available drugs with more favourable resistance profiles.

Facteurs de risque de syndrome d'hypersensibilité à l'Abacavir en pratique clinique de routine

Abacavir (ABC) is a generally well-tolerated NRTI. However, up to 5% of patients may develop hypersensitivity syndrome (HSS) within the first weeks of treatment. The objectives of this study were to describe the side effects of ABC, to evaluate the incidence of the ABC-HSS, and to identify the risk factors of HSS after first exposure to ABC in a cohort of patients followed up in a university HIV clinic.

METHODS

The charts of all HIV-infected patients who started ABC between February 1998 and May 2002 were reviewed. HSS was defined as the onset, within 8 weeks of ABC initiation, of either a skin rash associated with at least one of the following symptoms (fever, gastrointestinal symptoms, respiratory symptoms, myalgia, malaise) or at least three of the above symptoms in the absence of rash. A multivariate logistic regression analysis was performed to identify risk factors of HSS.

RESULTS

Of the 191 patients studied (134 M, 57 F, mean age 39 years), 53 (27.8%) presented with manifestations that were regarded as potential side-effects of ABC. Ten (5.2%) developed HSS, none of whom died. Two factors were independently associated with an increased risk of HSS: history of allergy to nevirapine (OR 8.1, 95% CI 1.6-40.5, p = 0.02), and being naïve to ART (OR 5.8, 95% CI 1.2-28.5, p = 0.04).

CONCLUSION

This study "in the real world" confirms that the incidence of ABC-induced HSS is of about 5%. It also confirms that HSS occurs more frequently in patients with a history of allergy to nevirapine and in ART-naïve patients.

G. Triple Nucleoside Combination Zidovudine/Lamivudine/Abacavir versus Zidovudine/Lamivudine/Nelfinavir as First-Line Therapy in HIV-1-Infected Adults: A Randomized Trial

Objective

To compare the efficacy and safety of a triple nucleoside combination to a protease inhibitor-containing triple regimen as first-line antiretroviral therapy (ART) in HIV-1-infected patients.

Design

Open-label study in HIV-1-infected ART-naive adults, randomized to receive either Combivir® (lamivudine 150 mg/zidovudine 300 mg twice daily) + abacavir (300 mg twice daily), or Combivir® + nelfinavir (750 mg every 8 h) for 48 weeks. Plasma HIV-1 RNA, CD4 cell count and adverse events were assessed at baseline and weeks 4, 8, 16, 24, 32, 40 and 48.

Results

195 subjects (131 men, 64 women), median age 34 years, were randomized: 98 received combivir/abacavir and 97 combivir/nelfinavir. Baseline median plasma HIV-1 RNA was 4.2 log10 copies/ml [Interquartile range (IQR): 3.7-4.5.2] and 4.1 log10 copies/ml (IQR: 3.8–4.6), respectively. Baseline median CD4 cell count was 387 cells/mm3 (IQR: 194–501) and 449 cells/mm3 (IQR: 334–605), respectively. Nine patients (3 vs 6, respectively) did not start treatment or did not have any available efficacy data. At week 48, using the intent to treat analysis (switch/missing equals failure), plasma HIV-1 RNA was <50 copies/ml in 54/95 (57%) and 53/91 (58%) of subjects, respectively. Median CD4 increase was +110 and +120 cells/mm3, respectively. Possible hypersensitivity reactions to abacavir were reported in four subjects (4%).

Conclusion

The triple nucleoside combination combivir/abacavir is well tolerated as a first-line ART regimen in HIV-1-infected adults, with comparable antiviral activity to a nelfinavir-containing regimen at week 48.

[Medicamentous kidney protection in type 2 diabetic patients--is cheaper also more economical? A model calculation for Swiss health care]

Impaired renal function occurs in about 50% of patients suffering from type 2 diabetes, and diabetic nephropathy has become the leading cause of endstage renal disease. Reduction of blood pressure to levels around 120/80 mmHg is one of the most effective way to slow progression of diabetic nephropathy. Recent meta-analyses, however, have emphasized on the fact that ACE inhibitors (ACEI) and non-dihydropyridine calcium channel blockers (NDHP-CCB) exert nephro-protective effects which go beyond the effect of blood pressure reduction. This has lately been confirmed by a prospective trial in comparison to the betablocker atenolol. Based on these data, demographics of the Swiss population, literature data on mortality rates of type 2 diabetics with impaired renal function and studies on true costs of antihypertensives, we calculated the costs of a longterm intervention (20 years) with antihypertensives in 3536 middle-aged Swiss patients with type 2 diabetes and macro-albuminuria whose antihypertensive regimen was based either on the ACEI lisinopril, or the ND-HP-CCB verapamil, or the betablocker atenolol. Under atenolol, acquisition costs were lowest, whereas faster loss of renal function over time increased mortality rate and thus reduced the number of patients to be treated. Nevertheless, due to the fact that patients reached uremia and had to be dialyzed, 20 years of atenolol-based regimen with costs of 316 millions of Swiss francs turned out to be much more expensive than the lisinopril- or the verapamil-based regimen with 121 and 38 millions of Swiss francs, respectively. Thus, low acquisition cost is not necessarily the only important determinant of overall costs of drug therapy.

[Gastrointestinal stromal tumors in our practice]

The classification of tumours originating from the wall of gastrointestinal organs changed dramatically since of electronmicroscopy and immunohystochemistry were introduced. Previously these tumours were classified as leiomyomas, leiomyosarcomas or schwannomas. With the new methods these disorders can be described in more details and unified, and so the change to provide correct prognosis improved. Still, there are some unanswered questions remaining for the pathologists. In our material in the past 5 year we treated 9 patients because of GIST. Most of them were found in the stomach (6), one developed in the oesophagus, one in the small bowel and another one in the rectum. With describe our patients and look at the related articles literature about this important diseases. Though the incidence is under 1% of patients operated on because of gastrointestinal diseases, we would like to share our experiences in treatment.

[Flesh-eating bacteria infection of an immunocompromised patient]

After years of steadily declining morbidity and mortality due to group A streptococcal infections, a resurgence of severe, invasive disease has been ongoing since 1980, leading to the recognition of streptococcal shock syndrome (STSS), necrotizing fasciitis, the most severe form of invasive infection. The patients suffer from rapid local deep soft tissue destruction, severe septic shock and multi organ failure. The increased incidence of these infections has been accompanied by remarkable vigor in virulence and severity of the disease. The reason for this impressive change in the epidemiology and clinical manifestation of group A streptococcal infections remains unknown. The possible etiological factor is changing in virulence factor or the lack of protective immunity of the population (immunocompromise) against the invasive strains. We describe a severe necrotizing fasciitis of a 41-year-old previously immunocompromised woman. The patient developed severe septic shock, multi organ failure and perineal and lower abdominal skin, fat and fascia necrosis due to mixed GAS (aerob, anaerob) infection of the perineum and the Bartholini glands. After an aggressive surgical debridement, antibiotic and supportive therapy the generalised and local infection was treated.

Respiratory changes in aortic blood velocity as an indicator of fluid responsiveness in ventilated patients with septic shock

STUDY OBJECTIVE

To investigate whether the respiratory changes in peak velocity (Vpeak) of aortic blood flow could be related to the effects of volume expansion on cardiac index.

DESIGN

Prospective clinical study.

SETTING

Medical ICUs of a university hospital (20 beds) and of a nonuniversity hospital (15 beds).

PATIENTS

Nineteen sedated septic shock patients who were receiving mechanical ventilation and who had preserved left ventricular (LV) systolic function.

INTERVENTION

Volume expansion.

MEASUREMENTS AND RESULTS

Analysis of aortic blood flow by transesophageal echocardiography allowed beat-to-beat measurement of Vpeak before and after volume expansion. Maximum values of Vpeak (Vpeakmax) and minimum values of Vpeak (Vpeakmin) were determined over one respiratory cycle. The respiratory changes in Vpeak (Delta Vpeak) were calculated as the difference between Vpeakmax and Vpeakmin divided by the mean of the two values and were expressed as a percentage. The indexed LV end-diastolic area (EDAI) and cardiac index were obtained at the end of the expiratory period. The volume expansion-induced increase in cardiac index was > or = 15% in 10 patients (responders) and < 15% in 9 patients (nonresponders). Before volume expansion, Delta Vpeak was higher in responders than in nonresponders (20 +/- 6% vs 10 +/- 3%; p < 0.01), while EDAI was not significantly different between the two groups (9.7 +/- 3.7 vs 9.7 +/- 2.4 cm(2)/m(2)). Before volume expansion, a Delta Vpeak threshold value of 12% allowed discrimination between responders and nonresponders with a sensitivity of 100% and a specificity of 89%. Volume expansion-induced changes in cardiac index closely correlated with the Delta Vpeak before volume expansion (r(2) = 0.83; p < 0.001).

CONCLUSION

Analysis of respiratory changes in aortic blood velocity is an accurate method for predicting the hemodynamic effects of volume expansion in septic shock patients receiving mechanical ventilation who have preserved LV systolic function.

Effect of extrusion on isoflavone content and antiproliferative bioactivity of soy/corn mixtures

The present studies were conducted to determine changes in the quantities of select isoflavones and in the bioactivity (ability to inhibit proliferation of human breast cancer cell lines) of extracts from blends of soy protein and cornmeal during extrusion processing. The extrusion of samples resulted in an average 24% decrease in the concentration of total isoflavones for all samples. Although the amounts of specific genistein-derived and daidzein-derived forms changed following extrusion, the content of the aglycones genistein and daidzein per g sample generally did not change. The extrusion of samples generally resulted in decreased antiproliferative action toward breast cancer cells, although antiproliferative activity was not eliminated. Therefore, extrusion of soy protein/cornmeal-containing foods are likely to retain a considerable portion of their isoflavone content and some of the health benefits associated with soy.

Isolated massive pleural effusion caused by pancreatico-pleural fistula

BACKGROUND

Massive pleural effusions are uncommon but well-documented complications of chronic pancreatitis, usually caused by the development of a pancreaticopleural fistula. The mechanism of the fistula formation is thought to be rupture of the pancreatic duct or pseudocyst.

MATERIAL AND METHODS

In the past 7 years we have treated 5 patients with massive pleural effusion of pancreatic origin in the Surgical Department of Semmelweis University Medical School. 4 patients were males; the average age was 52 years (range: 46-59 years).

RESULTS

All 5 patients had a history of alcohol abuse and were admitted to the pulmonary department because of respiratory distress. Other symptoms such as abdominal pain, chest pain, or weight loss were not always present. The diagnosis was confirmed by a markedly elevated amylase level in the aspirated pleural fluid. Abdominal ultrasound, CT scan, and ERCP examinations were carried out in order to determine the cause of the pancreaticopleural fistula. Conservative (nonsurgical) treatment was effective within 3 weeks in only one case. The other 4 patients required surgical management. In 3 cases distal pancreatic resection with splenectomy and cholecystectomy was done. In one case cystojejunostomy was performed. All 5 patients have been cured with complete resolution of their pleural effusions.

CONCLUSIONS

Patients with large pleural effusions may have underlying pancreatitis with a pancreaticopleural fistula. It is important to establish this diagnosis because treatment may require operative interventions.

Stability of isoflavones during extrusion processing of corn/soy mixture

The influence of extrusion processing in the presence of corn on the quantity and quality of genistein, daidzein, and their respective beta-glucoside, acetyl glucoside, and malonyl glucoside derivatives was evaluated. Products of 100% soy (textured) and a blend of 20% soy protein concentrate (SPC) and 80% corn meal (direct-expanded) were extruded, with evaluations before and after extrusion. In addition, a 3 x (3 x 3) split-plot factorial experiment investigated the influence of barrel temperature (110, 130, 150 degrees C), moisture content (22, 24, 26%), and relative residence time (1, 0.8, 0.6) on extruder response and isoflavone profile. The extrusion barrel temperature had the most influence on isoflavone profile, especially decarboxylation of the malonyl beta-glucoside, followed by the moisture content. The amount of extractable isoflavones decreased after extrusion for both the SPC and SPC/corn meal blend when extracted with 80% aqueous methanol but remained approximately the same when first hydrated with water before extraction. However, initially hydrating with water produced enzymatic glycolysis in the unextruded samples, increasing the aglycons dramatically.

[Abdominal trans-sphincter resection of the anus: new possibilities in the surgical management of deep rectal cancer, with preservation of the anal sphincter]

The last decade has brought marked changes in the surgical treatment of rectal cancer: as the indication of the sphincter-saving procedures was extended, the rate of the abdomino-perineal excision has decreased even in the case of tumours of the distal third of the rectum. However, even with the use of the modern stapling devices, the anterior resection and colo-anal anastomosis may not always be feasible by the traditional abdominal approach. In these cases the sphincter-saving resection can be performed by a particular approach, the abdomino-transsphincteric technique. The authors present this seldom used operation. From the 1-st of January 1994 to the 31-st of August 1996 14 abdomino-transsphincteric resections have been performed. The mean age of the patients was 62.2 (38-81) years. The lower edge of the tumours was situated at 6.3 (5-8) cm from the anal verge. The anastomosis was performed by the double stapling technique in 8 and by hand suture in 6 cases, its distance from the anal verge was 3.2 (3-4) cm. A colon J-pouch was used in 3 cases and a diverting colostomy was performed routinely. One patient died in the postoperative period and a reoperation (abdomino-perineal excission) was performed because of left colon necrosis: Anastomotic leakage was observed in one case. By the time of the present study, 11 patients have had their colostomies closed. The continence is acceptable in every case and all the patients experience a better subjective quality of life, than it was while wearing the colostomy. The use of this technique has helped to avoid a permanent colostomy in 21 out of 33 cases operated on for cancer of the distal rectal third in the reviewed period.