On central focusing for contrast optimization in direct electron ptychography of thick samples

Ptychography provides high dose efficiency images that can reveal light elements next to heavy atoms. However, despite ptychography having an otherwise single signed contrast transfer function, contrast reversals can occur when the projected potential becomes strong for both direct and iterative inversion ptychography methods. It has recently been shown that these reversals can often be counteracted in direct ptychography methods by adapting the focus. Here we provide an explanation of why the best contrast is often found with the probe focused to the middle of the sample. The phase contribution due to defocus at each sample slice above and below the central plane in this configuration effectively cancels out, which can prevent contrast reversals when dynamical scattering effects are not overly strong. In addition we show that the convergence angle can be an important consideration for removal of contrast reversals in relatively thin samples.

Event driven 4D STEM acquisition with a Timepix3 detector: Microsecond dwell time and faster scans for high precision and low dose applications

Four dimensional scanning transmission electron microscopy (4D STEM) records the scattering of electrons in a material in great detail. The benefits offered by 4D STEM are substantial, with the wealth of data it provides facilitating for instance high precision, high electron dose efficiency phase imaging via centre of mass or ptychography based analysis. However the requirement for a 2D image of the scattering to be recorded at each probe position has long placed a severe bottleneck on the speed at which 4D STEM can be performed. Recent advances in camera technology have greatly reduced this bottleneck, with the detection efficiency of direct electron detectors being especially well suited to the technique. However even the fastest frame driven pixelated detectors still significantly limit the scan speed which can be used in 4D STEM, making the resulting data susceptible to drift and hampering its use for low dose beam sensitive applications. Here we report the development of the use of an event driven Timepix3 direct electron camera that allows us to overcome this bottleneck and achieve 4D STEM dwell times down to 100 ns; orders of magnitude faster than what has been possible with frame based readout. We characterize the detector for different acceleration voltages and show that the method is especially well suited for low dose imaging and promises rich datasets without compromising dwell time when compared to conventional STEM imaging.

Enhanced intrapulse difference frequency generation in the mid-infrared by a spectrally dependent polarization state

We present a technique to optimize the intrapulse difference frequency generation efficiency for mid-infrared generation. The approach employs a multi-order wave plate that is designed to selectively rotate the polarization state of the incoming spectral components on the relevant orthogonal axes for subsequent nonlinear interaction. We demonstrate a significant increase of the mid-infrared average power generated, of a factor ≥2.5 compared with the conventional scheme, owing to an optimally distributed number of photons enrolled in the difference frequency generation process.

Long-term implant of intramuscular sensors and nerve transfers for wireless control of robotic arms in above-elbow amputees

Targeted muscle reinnervation (TMR) amplifies the electrical activity of nerves at the stump of amputees by redirecting them in remnant muscles above the amputation. The electrical activity of the reinnervated muscles can be used to extract natural control signals. Nonetheless, current control systems, mainly based on noninvasive muscle recordings, fail to provide accurate and reliable control over time. This is one of the major reasons for prosthetic abandonment. This prospective interventional study includes three unilateral above-elbow amputees and reports the long-term (2.5 years) implant of wireless myoelectric sensors in the reinnervation sites after TMR and their use for control of robotic arms in daily life. It therefore demonstrates the clinical viability of chronically implanted myoelectric interfaces that amplify nerve activity through TMR. The patients showed substantial functional improvements using the implanted system compared with control based on surface electrodes. The combination of TMR and chronically implanted sensors may drastically improve robotic limb replacement in above-elbow amputees.

Watt-scale 50-MHz source of single-cycle waveform-stable pulses in the molecular fingerprint region

We report a coherent mid-infrared (MIR) source with a combination of broad spectral coverage (6-18 μm), high repetition rate (50 MHz), and high average power (0.5 W). The waveform-stable pulses emerge via intrapulse difference-frequency generation (IPDFG) in a GaSe crystal, driven by a 30-W-average-power train of 32-fs pulses spectrally centered at 2 μm, delivered by a fiber-laser system. Electro-optic sampling (EOS) of the waveform-stable MIR waveforms reveals their single-cycle nature, confirming the excellent phase matching both of IPDFG and of EOS with 2-μm pulses in GaSe.

Use of failure-to-rescue to identify international variation in postoperative care in low-, middle- and high-income countries: a 7-day cohort study of elective surgery

Background

The incidence and impact of postoperative complications are poorly described. Failure-to-rescue, the rate of death following complications, is an important quality measure for perioperative care but has not been investigated across multiple health care systems.

Methods

We analysed data collected during the International Surgical Outcomes Study, an international 7-day cohort study of adults undergoing elective inpatient surgery. Hospitals were ranked by quintiles according to surgical procedural volume (Q1 lowest to Q5 highest). For each quintile we assessed in-hospital complications rates, mortality, and failure-to-rescue. We repeated this analysis ranking hospitals by risk-adjusted complication rates (Q1 lowest to Q5 highest).

Results

A total of 44 814 patients from 474 hospitals in 27 low-, middle-, and high-income countries were available for analysis. Of these, 7508 (17%) developed one or more postoperative complication, with 207 deaths in hospital (0.5%), giving an overall failure-to-rescue rate of 2.8%. When hospitals were ranked in quintiles by procedural volume, we identified a three-fold variation in mortality (Q1: 0.6% vs Q5: 0.2%) and a two-fold variation in failure-to-rescue (Q1: 3.6% vs Q5: 1.7%). Ranking hospitals in quintiles by risk-adjusted complication rate further confirmed the presence of important variations in failure-to-rescue, indicating differences between hospitals in the risk of death among patients after they develop complications.

Conclusions

Comparison of failure-to-rescue rates across health care systems suggests the presence of preventable postoperative deaths. Using such metrics, developing nations could benefit from a data-driven approach to quality improvement, which has proved effective in high-income countries.

A novel mechanotronic orthosis enables symmetrical gait kinematics in a patient with a femoral nerve palsy - a case study

The usage of stance- and swing-phase control orthoses (SSCOs) is a good option in patients with neuromuscular insufficiency of the quadriceps muscle in a broad range of musculo-skeletal disorders. The subjective sensation of improved mobility in daily life and walking comfort could be objectively confirmed by the ability to walk without crutches and by harmonization of the gait patterns in hip and knee. They could also be a considered mobility device after limb salvage surgery, which may even have an impact on preoperative decision making. IMPLICATIONS FOR REHABILITATION Symmetric gate in spite of femoral nerve palsy. Early gate improvements even after hours. High patient?s motivation to use the device.

Enhancement cavities for few-cycle pulses

We address the challenge of increasing the bandwidth of high-finesse femtosecond enhancement cavities and demonstrate a broad spectrum spanning 1800  cm^-1 (195 nm) at -10  dB around a central wavelength of 1050 nm in an EC with an average finesse exceeding 300. This will benefit a host of spectroscopic applications, including transient absorption spectroscopy, direct frequency comb spectroscopy, and Raman spectroscopy. The pulse circulating in the EC is composed of only 5.4 optical cycles, at a kilowatt-level average power. Together with a suitable gating technique, this paves the way to the efficient generation of multi-megahertz-repetition-rate isolated extreme ultraviolet attosecond pulses via intracavity high-order harmonic generation.

[Lichen sclerosus in the genitourinary region]

Lichen sclerosus (LS) is a chronic inflammatory disorder of the skin and mucosa, presenting to genitourinary physicians, pediatricians, and dermatologists. It affects both sexes with a lower incidence in men than in women. Autoimmune factors, infections, and genetic disposition are implicated in its pathogenesis. The classic clinical picture is of atrophic white plaques in the anogenital region. Pruritus, soreness, difficulty retracting the foreskin, and obstructive urinary symptoms are frequent complaints. Early histological confirmation by biopsy is recommended. The disorder is usually highly responsive to ultrapotent topical steroids. This may help arrest or delay the progressive nature of this disorder. Surgical treatment may be needed in cases of disease progression despite medical therapy. Circumcision is a successful treatment, if LS is limited to the glans and foreskin. In cases of meatal stenosis meatoplasty and in cases of urethral involvement one- or two-stage oral graft urethroplasty is necessary.

Stable muscle atrophy in long-term paraplegics with complete upper motor neuron lesion from 3- to 20-year SCI

STUDY DESIGN

Unrandomized trial.

OBJECTIVES

To investigate the structural and functional relationships and the progression of muscle atrophy up to 20 years of spastic paraplegia.

SETTING

Clinical follow-up in Vienna, Austria; muscle biopsies analyzed by light microscopy in Padova and by electron microscopy (EM) in Chieti, Italy.

METHODS

Force was measured as knee extension torque; trophism by computer tomography scan; tissue composition and fiber morphology by histopathology and EM.

RESULTS

In the long-term group of patients (17.0+/-2.6 years), force and size of thigh muscles were only slightly different from those of mid-term subjects (2.2+/-0.5 years). Histology and ultrastructure confirm that the difference in average size of muscle fibers between long-term and mid-term paralyzed leg muscles is actually very small. In addition, muscle fibers maintain the striated appearance characteristic of normal skeletal fibers even after 14-20 years of paralysis. Ultrastructural alterations of the activating and metabolic machineries, and the presence of fibers with lower motor neuron denervation features, may explain the low-force output and the reduced endurance of paretic muscles.

CONCLUSION

The stable muscle atrophy that characterizes long-lasting spastic paraplegia suggests that there are no upper-time limits to begin a training program based on functional electrical stimulation.

Off-Pump Coronary Artery Bypass Grafting: The Zurich Experience

Coronary artery bypass grafting (CABG) is the surgical procedure of choice for treatment of multi-vessel coronary artery disease. The rising risk profile of the patients requiring isolated CABG and the economic pressure have prompted us to devise new operative strategies to treat these patients. Elimination of the cardiopulmonary bypass is one possible answer to the dilemma of maintaining the quality of care and reducing the exploding costs of our health system. Therefore, we developed the off-pump coronary artery bypass grafting (OPCAB) for patients requiring isolated CABG. In our experience the key to successful OPCAB relies on the order of revascularization of the myocardial walls (anterior, inferior, lateral), use of intracoronary shunt, no-touch technique for the proximal aortic anastomosis with heart string â (Guidant, IN, USA), close collaboration with the anesthesiologists, early and aggressive administration of anti-platelet therapy, endoscopic vein harvest by perfusionists, and improved body temperature control. Following these concepts, we have been able to offer the OPCAB procedure to over 90% of our patients and to reduce perioperative morbidity and global costs.

Defaulting from anti-tuberculosis treatment in a teaching hospital in Rio de Janeiro, Brazil

SETTING

Few studies have investigated factors associated with defaulting from anti-tuberculosis (TB) therapy in hospital settings.

OBJECTIVE

To identify the factors associated with defaulting from treatment among TB in-patients in Rio de Janeiro city, Brazil.

DESIGN

Case-control study.

METHODS

All study participants initiated anti-tuberculosis treatment in a teaching hospital. A defaulting case was defined as a person who did not return for anti-tuberculosis medications after 60 days. Cases and controls were interviewed by a trained health care worker using a standardized form.

RESULTS

From 1 January to 31 December 1997, 228 TB cases were registered. After a review of the medical records, 39 were excluded. Household visits were performed in 189 patients; 46 subjects were identified as cases and 117 as controls. Defaulting from anti-tuberculosis treatment was observed in 66 cases (28.9%) before and in 46 (20.2%) after a home visit. After multivariate analysis, the strongest predictors of defaulting from treatment were: 1) returning card not provided (OR 0.099; 95%CI 0.008-1.2; P = 0.07), 2) not feeling comfortable with a doctor (OR 0.16; 95%CI 0.33-0.015; P = 0.001), and 3) blood pressure not measured (OR 0.072; 95%CI 0.036-0.79; P = 0.024).

CONCLUSIONS

In this hospital, the factors associated with defaulting from anti-tuberculosis treatment highlight the necessity for a structured TB Control Program. It is expected that the implementation of such a program, pursuing specific approaches, should enhance completion of anti-tuberculosis treatment and cure.

Total intravenous anaesthesia in a patient with familial hypokalaemic periodic paralysis

A 35-year-old woman with known familial hypokalaemic periodic paralysis received general anaesthesia for reduction of bilateral breast hyperplasia. Uncomplicated general anaesthesia was performed using a propofol target-controlled infusion, remifentanil infusion and bolus doses of mivacurium with neuromuscular function monitoring. Plasma potassium concentrations were controlled intermittently in the peri-operative period and supplemented to achieve normokalaemia. Despite continuous substitution, an episode of low plasma potassium concentration occurred during the recovery period; this was without any clinical signs of muscle paralysis or respiratory distress.

Diagnosis and monitoring of urological tumors using positron emission tomography

The purpose of this article was to critically review the diagnostic value of positron emission tomography (PET) in urological oncology. Urinary tract tumor assessment is hampered by the renal elimination of (18)F-fluorodeoxyglucose (FDG), the most commonly used PET radiopharmaceutical. PET imaging offers no significant benefits over conventional imaging modalities for renal cell and bladder carcinomas. As a result of the low metabolic activity of prostate cancer, PET does not differentiate adequately between adenoma and carcinoma, nor detect local recurrence after radical prostatectomy with sufficient sensitivity. However, lymph node staging with FDG-PET, specifically in bladder cancer, has been shown to have a potential clinical benefit. Further studies are required to determine the clinical value of retroperitoneal lymph node staging and recurrent disease detection in germ cell tumors. Finally, encouraging early results exist for the use of serial PET measurements to predict and assess therapy response to chemotherapy which may also be valuable in urological oncology.

Test bed with force-measuring crank for static and dynamic investigations on cycling by means of functional electrical stimulation

Cycling by means of functional electrical stimulation (FES) is an attractive training method for individuals with paraplegia. The physiological benefits of FES are combined with the psychological incentive of independent locomotion. In addition, cycling has the advantage in that the generated muscle forces are converted into drive power with relatively high efficiency compared to other means of locomotion, e.g., walking. For the design of an appropriate cycling device and the development of optimal stimulation patterns, it has to be investigated how the geometry for FES cycling, influenced by individual parameters of the FES-generated drive torques and the magnitude of variations among subjects with paraplegia, can be optimized. This study shows the design of a freely adjustable test bed with additional motor drive which allows static and dynamic measurements of force components and drive torque at the crank. Furthermore, the influence of geometry and various individual parameters on FES pedaling can be tested for each subject individually. A pedal path realized by a three-bar linkage that was optimized according to preliminary simulations further increases leg cycling efficiency. Safety precautions avoid injuries in case of excessive forces, e.g., spasms. Test results illustrate the application of the test bed and measurement routines. A test series with four paraplegic test persons showed that the presented static and dynamic measurement routines allow to provide optimal stimulation patterns for individual paraplegic subjects. While pedaling with these optimal stimulation patterns only negligible negative active drive torques, due to active muscle forces, were applied to the crank and sufficient drive power was generated to power a cycle independently.

New ultradeformable drug carriers for potential transdermal application of interleukin-2 and interferon-alpha: theoretic and practical aspects

Transfersomes (TFs) are highly deformable hydrophilic lipid vesicles that are able to penetrate the skin barrier spontaneously because of their characteristics. Transfersomes are able to transport noninvasively low- and high-molecular-weight molecules into the body. We describe the formulation and several biologic characteristics of interleukin-2 (IL-2)- and interferon-alpha (IFNalpha )-containing TFs. TFs contain natural phosphatidylcholine and sodium cholate. Recombinant human IL-2 and human hybrid IFNalpha were added to TFs and incubated for 24 hours at 4 degrees C. Immunotransfersomes were isolated from free IL-2 and IFNalpha by filtration (Centrisart, Sartorius). The biologic activity of immunotransfersomes was measured by a cytotoxic lymphoid line assay for IL-2 and by an A549-encephalomyocarditis virus assay for IFN; concentrations of proteins were determined by the enzyme-linked immunosorbent assay (ELISA). It was possible to incorporate a large amount of IL-2 and IFN in TFs (75-80%), and the incorporated IL-2, and IFN were biologically active. The increased lipid/protein ratio (90.9/1.0) led to a growing probability of association. We were thus able to show that IL-2 and IFN are trapped by transfersomes in a biologically active form and in sufficient concentrations for immunotherapy. In upcoming experiments these IL-2- and IFN-containing TFs will be used for a transdermal approach in the murine RENCA cell line model.

Value of free prostate-specific antigen (Hybritech Tandem-R) in symptomatic patients consulting the urologist

INTRODUCTION

Prostate-specific antigen (PSA) is a widely used tumor marker in the detection and follow-up of adenocarcinoma of the prostate. Selection of candidates for prostate biopsies is hampered by the lack of specificity resulting in a large number of unnecessary biopsies. The intention of our study was to compare the percent free PSA (f-PSA; Hybritech Tandem-R) with total PSA and age-specific PSA reference values to evaluate the clinical benefit in detecting patients with prostate cancer (PC) in a selected group of patients consulting the urologist. The question was whether cutoff points are influenced by this selection of patients.

METHODS

A total of 188 patients, 114 with benign prostate hyperplasia (BPH) and 74 with PC were selected. It is a selected group of patients consulting the urologist. Diagnosis was confirmed in the BPH and PC groups by either ultrasound-guided biopsy or transurethral resection of the prostate or suprapubic adenomectomy or cystoprostatectomy. Total PSA (t-PSA) and f-PSA of all patients were measured before any manipulation by Tandem-R assay for f-PSA and Tandem-E assay for t-PSA (Hybritech). Mean values of age, prostate volume, t-PSA, f-PSA, percent f-PSA were compared in patients with BPH and PC by Mann-Whitney U test. The sensitivity and specificity of t-PSA and age-specific PSA were compared to the sensitivities and specificities of different cutoff points of percent f-PSA.

RESULTS

The mean value of t-PSA, f-PSA and percent f-PSA in patients with BPH (n = 114) and PC (n = 74) were statistically significantly different. At PSA levels between 4 and 10 ng/ml 19% of negative biopsies could be avoided by the use of percent f-PSA (cutoff point 25%). There was no additional benefit of age-specific PSA. At a PSA of <4 ng/ml 6 of 7 PCs could be diagnosed by percent f-PSA (cutoff point 25%), whereas only 1 patient would be diagnosed by age-specific PSA.

CONCLUSION

Percent f-PSA seems to decrease the biopsy rate at PSA levels from 4 to 10 ng/ml without missing a relevant number of cancers and to increase the detection rate at PSA <4 ng/ml. Our data indicate that it might be necessary to choose high cutoff points (25%; Tandem-E and R assay, Hybritech) in a selected study population consulting the urologist with large glands and a high prevalence of disease. However, this situation is not comparable to testing of screening populations. No benefit of age-specific PSA could be observed in this study.

RFLP patterns and risk factors for recent tuberculosis transmission among hospitalized tuberculosis patients in Rio de Janeiro, Brazil

Isolates of Mycobacterium tuberculosis from 120 tuberculosis patients seen in the 12 months ending September 1994 at 2 tertiary-care centres in Rio de Janeiro were characterized by IS6110 restriction fragment length polymorphism (RFLP) analysis. Ninety-seven patients (81%) had isolates with unique RFLP patterns, while 23 patients (19%) had isolates that belonged to 11 different RFLP cluster patterns. The strains from the latter patients were distributed among 1 group of 3 patients and 10 groups of 2 patients each. The cluster-pattern strains were not associated with gender, age, HIV infection, type of residence, living in shelter, homelessness or previous history of tuberculosis. However, clustering was strongly associated with multidrug resistance (P = 0.006). These data suggest that recent exogenous transmission may be important for the development of new cases of multidrug-resistant disease in patients attending tertiary-care centres in Rio de Janeiro, Brazil.

Drug resistance patterns among hospitalized tuberculous patients in Rio de Janeiro, Brazil, 1993-1994

The purpose of this study was to analyze the prevalence and risk factors for drug resistance among hospitalized patients in two tertiary care centers, an acquired immunodeficiency syndrome (AIDS) reference center and a sanatorium, in Rio de Janeiro, Brazil. From 1993-1994, 389 patients were diagnosed as having tuberculosis (TB). Isolates from 265 patients were tested for in vitro susceptibility to rifampin and isoniazid. Resistance to one or more drugs was detected in 44 patients (16.6%) and was significantly more common among recurrent cases in both hospitals (p=0.03 in the AIDS center and p=0.001 in the sanatorium). Twenty seven patients (10.2%) had isolates resistant to both isoniazid and rifampin. Multi-drug resistance was associated with human immunodeficiency virus (HIV) infection among patients who had never been treated for TB. In conclusion, drug-resistant TB is high in hospitalized patients in Rio de Janeiro, especially among HIV infected patients. Therefore, measures to control TB and prevent nosocomial transmission need urgently to be set up in the Brazilian hospitals.

Fluorine-18-fluorodeoxyglucose positron emission tomography is useless for the detection of local recurrence after radical prostatectomy

OBJECTIVE

After radical retropubic prostatectomy a rise of the prostate-specific antigen (PSA) indicates a local recurrent or metastatic disease. If the bone scan shows no apparent bone metastasis, morphological imaging methods like x-ray computed tomography, magnetic resonance imaging or transrectal ultrasound often cannot distinguish between postoperative scar and local recurrence. Therefore we investigated the feasibility of fluorine-18-fluorodeoxyglucose positron emission tomography (F-18 FDG PET) for metabolic characterization of prostatic cancer, especially for differentiation of scar or recurrent prostate cancer after radical prostatectomy.

METHODS

Dynamic PET with 370 MBq F-18 deoxyglucose (F-18 FDG) up to 60 min p.i. was performed in 2 patients with biopsy-proven benign prostatic hyperplasia, in 11 patients with a histologically proven prostate cancer prior to radical retropubic prostatectomy (RRP) and 7 patients with suspected local recurrence (with negative bone scan) after RRP prior to biopsy of anastomosis (3 local recurrence, 4 postoperative scar).

RESULTS

Prostate cancer showed a very low F-18 FDG uptake. The placement of regions of interest was only possible by the use of other imaging methods. There was not difference between the F-18 FDG uptake of benign prostate hyperplasia, prostate carcinoma, postoperative scar or local recurrence after radical prostatectomy.

CONCLUSION

F-18 FDG seems not to be useful to distinguish between postoperative scar and local recurrence after radical prostatectomy.

MYOSTIM-FES to prevent muscle atrophy in microgravity and bed rest: preliminary report

Long-term flights in microgravity cause atrophy and morphological changes of skeletal muscles. Training with mechanical devices is insufficient regarding the required time to exercise and space for devices. The objective of this project is to develop a passive training method based on functional electrostimulation (FES) to preserve muscle mass and fiber composition with minimal impairment to the cosmonaut. For a pilot experiment on the MIR space station, a suitable 8 channel FES device was developed. It consists of electrode trousers that carry surface electrodes and cables, 2 interconnected 4 channel stimulators, and a laptop personal computer (PC) for stimulator programming and processing compliance data. An automatic extensive training of 4 muscle groups of the lower extremities is performed for 6 h/day, with 1 s on and 2 s off tetanic contractions at 20-30% of maximum tetanic muscle force. The synchronous activation of antagonists of the thigh and lower leg prevents uncoordinated movements.

Standing up with denervated muscles in humans using functional electrical stimulation

The use of electrical stimulation for denervated muscles is still considered to be a controversial issue by many rehabilitation facilities and medical professionals because prior clinical experience has shown that treating denervated muscle tissue using exponential current over a long time period constitutes an impossible task. Despite this fact, we managed to evoke tetanic contractions in denervated muscle using a long duration stimulation with anatomically shaped electrodes and sufficiently high amplitudes. The pulse amplitudes, which were being used for this purpose, exceeded by far the MED-GV and EC regulations (300 mJ/impulse). For this reason, an application has recently been submitted to have the EC regulations changed accordingly. It takes a tetanic contraction to achieve the desired muscle fiber tension, constituting a hypertrophic stimulus. It is also an appropriate means of exercise, which is capable of creating the metabolic and structural conditions needed (e.g, increased mitochondrial volume and capillary density) to obtain satisfactory muscle performance. With patients suffering from a complete spinal cord injury at level D12/L1, having motor and sensory loss in both lower extremities, we were able to train denervated muscle using long-duration stimulation, evoking single muscle contractions at first, soon followed by tetanic contractions against gravity. To increase the efficacy of this functional electrical stimulation (FES) strengthening program, we used ankle weights. With daily FES training over a period of 1-2 years, denervated muscle was exercised until it produced torques between 16 and 38 Nm in the m. quadriceps. With that muscle force, it is possible to stand up from a sitting position in parallel bars. Our results show that denervated muscle in humans is indeed trainable and can perform functional activities with FES. Furthermore, this method of stimulation can assist in decubitus prevention and significantly improve the mobility of paraplegics.

Electromyogram-controlled functional electrical stimulation for treatment of the paralyzed upper extremity

Spinal cord lesions at level C5 to C6 lead to loss of hand functions and lesions at C4 to additional deficits of arm functionality. The presented dual channel surface stimulator with dual channel electromyogram (EMG) measurement was developed to investigate control strategies for an EMG-controlled implantable stimulation system and serves in addition as a therapy device for patients with partial innervation but weak muscle force. Four different control strategies for stimulation amplitude are available. The amplitude can be preset manually or can follow the preprocessed EMG signals proportionally. The shoulder control program allows proportional control of both stimulation channels with one EMG channel while the second EMG channel serves as the channel selector. Finally, a special feedback training program triggers a stimulation burst when EMG activity is detected. During a 2 year patient study, 18 patients from 2 hospitals and 1 rehabilitation center performed the feedback training. Almost all patients obtained an improvement of functionality. Apart from muscle strengthening, the feedback effect led to an improvement of proprioception and supported relearning of motions. For the documentation of the training status, functional muscle test (British Medical Research Council) and measurements of power, angle, torque, muscle fatigue, and EMG were performed. Obviously, EMG triggered stimulation provides several advantages compared to conventional passive electrical stimulation.

Personal computer supported eight channel surface stimulator for paraplegic walking: first results

Today functional electrical stimulation (FES) is used among other treatments to restore hand and arm function, to restore mobility of the lower extremities, for phrenic pacing, and in cardiomyoplasty. Common to all FES applications is that they require careful setup of stimulation parameters. To improve these tasks, personal computer (PC) based software for stimulation parameter evaluation and data acquisition was written. First, the described software was used to mobilize paraplegic patients in conjunction with an 12C bus controlled 8 channel surface stimulator. Electrodes were placed on each leg on the m. quadriceps and m. gluteus for hip and knee extension and the peroneal nerve to elicit flexion reflex. The fourth channel was used to correspond to subjects' individual needs. The stimulation patterns for standing up, walking, and sitting down easily could be set up and optimized by adjusting up to 128 stimulation parameters in a task-specific way.

Formulation of interleukin-2 and interferon-alpha containing ultradeformable carriers for potential transdermal application

INTRODUCTION

Transfersomes (TF) are new highly deformable hydrophilic lipid vesicles, which are able to spontaneously penetrate the skin barrier because of their characteristics. Transfersomes are able to transport non-invasively low as well as high molecular weight molecules into the body. We describe the formulation and several biological characteristics of Interleukin-2 and Interferon-a containing TF.

MATERIAL AND METHODS

TF contain natural phosphatidylcholine and sodium cholate. Recombinant human IL-2 and human hybrid interferon-alpha A/D were added to TF and incubated for 24 hours at 4 degrees C. Immunotransfersomes were isolated from free IL-2 and IFN by filtration (Centrisart, Sartorius). Biological activity of immunotransfersomes was measured by CTLL-cell-assay for IL-2 and by A549--EMCV-assay for IFN, concentrations of proteins by ELISA.

RESULTS

It has been possible to incorporate a high amount of IL-2 and IFN in TF (75-80%). Incorporated IL-2 and IFN were biological active. The increase of the proportion of lipid to protein to 90.9/1 led to growing probability of association.

CONCLUSION

We were able to show, that IL-2 as well as IFN is trapped by transfersomes in biological active form and in sufficient concentrations for immunotherapy. In upcoming experiments these IL-2 and IFN-containing TF are used for a transdermal approach in the murine RENCA cell line model.

Gender and survival after AIDS in Rio de Janeiro, Brazil

The relation between gender and survival after a diagnosis of AIDS was studied in a cohort of patients with HIV infection in Rio de Janeiro, Brazil. During the study period, 124 of 617 patients (20%) developed AIDS. Of this group, 91 patients were men and 33 were women. There were no gender related differences regarding the access to antiretroviral therapy or to prophylaxis for Pneumocystis carinii pneumonia. Survival was shorter among women (hazard ratio [HR] = 4.43; p < .001) after adjustment for age and AIDS-defining condition. Adjusting for CD4+ and CD8+ counts reduced the difference between genders (HR = 3.33; p = .017). These results suggest that survival after an AIDS diagnosis may be shorter among women than men in Brazil. Further studies are needed to determine the factors that may be negatively influencing the prognosis of women with AIDS in Brazil.

Strategies for managing group A streptococcal pharyngitis. A survey of board-certified pediatricians

OBJECTIVE

To assess the management strategies and knowledge of board-certified pediatricians regarding group A beta-hemolytic streptococcal (GABHS) pharyngitis.

DESIGN

Survey of 1000 US pediatricians in 1991, chosen randomly from the membership of the American Academy of Pediatrics. The survey included questions related to 2 clinical scenarios, respondent demographics, and knowledge of streptococcal pharyngitis.

SUBJECTS

Pediatricians who treated patients with pharyngitis. Of the 690 surveys that were returned, 510 pediatricians treated patients with pharyngitis and were included in the data analysis.

DATA ANALYSIS

Data were analyzed using Chi 2 statistics for categorical data and the Student t test for continuous variables.

RESULTS

Antigen detection tests (ADTs) were used by 64% of the pediatricians; 85% used throat cultures. Strategies for diagnosing streptococcal pharyngitis were throat culture alone (38%), consider positive ADTs definitive and use throat culture when ADTs are negative (42%), ADT alone (13%), ADT and throat culture for all patients with pharyngitis (5%), and no tests for GABHS performed (2%). Thirty-one percent usually or always treated with antibiotics before test results were available. Only 29% of these "early treaters" always discontinued antibiotics when tests did not confirm the presence of group A streptococci. The drug of choice for treatment was penicillin (73%); another 26% preferred a derivative of penicillin, particularly amoxicillin. Many pediatricians altered their management when a patient had recurrent streptococcal pharyngitis. Nearly half of the respondents would use a different antibiotic than they used for routine acute streptococcal pharyngitis. They most often changed to erythromycin (25%), cefadroxil (23%), or amoxicillin-clavulanate (20%). Follow-up throat culture was obtained by 51% of pediatricians after treatment of recurrent streptococcal pharyngitis. A patient with chronic carriage of GABHS and symptoms of pharyngitis would be treated with an antibiotic by 84%; most (62%) would use a penicillin. Other choices were cephalosporins (19%), erythromycin (12%), clindamycin (3%), or rifampin plus penicillin (3%). Tonsillectomy was recommended for symptomatic carriers by 31% of respondents. Carriers without symptoms were less likely to be treated with antibiotics (23%) or referred for tonsillectomy (21%).

CONCLUSIONS

Most surveyed board-certified pediatricians managed acute GABHS pharyngitis appropriately, but 15% to 20% used diagnostic or treatment strategies that are not recommended. There was lack of a consensus about the management of recurrent GABHS pharyngitis and chronic carriage of GABHS.

The ceramic cup type Lindenhof. Results 10-14 years after implantation

We followed up 10-14 years postoperatively the 106 ceramic cups type 'Lindenhof' that were implanted in the years 1978-1982. In that time, only 7 (6.6%) cups had to be changed due to aseptic loosening. Examination of 73 (68.9%) cups showed that only 4% of the patients were dissatisfied. Using the score of Merle d'Aubigne, we found 89% good and very good results. The high number of cup migrations reported by other authors could not be verified: we saw 35% in all. Most of them appeared in the early postoperative period, stabilized themselves and were not accompanied by pain. Our 10-year survival rate for this ceramic cup is 92%, including the septic changing of arthroplasties.

[Report of experience in reconstruction of the lower urinary tract in the man and woman]

For some decades uretero(ileo) cutaneostomy and ureterosigmoidostomy were the methods of choice for urinary diversion in cystectomized patients. In recent years, lower urinary tract reconstruction with an anastomosis from an intestinal urinary reservoir to the urethra has established itself as an alternative for male patients undergoing cystectomy. We present the results obtained in 35 patients (32 men, 3 women) who chose to have a ureteroileal urethrostomy to the residual urethra after radical cystectomy for bladder cancer. These patients were followed up by clinical, serologic, radiographic, and urodynamic evaluation conducted at short intervals according to a strict protocol. There was no perioperative mortality, and the early postoperative complication rate was 17% (6/35 patients). For all patients, including those followed only for 3 months so far, the diurnal continence rate was 87% and the nocturnal continence rate was 78%. In every patient, male and female, the maximum urethral pressure (average value in the urethra pressure profile 50.8 cm H2O) was higher than the average resting intraluminal pressure in the pouch (average 12 cm H2O) with physiologic capacity (250-550 ml) of the urinary bladder. Patient acceptance, measured on a numerical self-rating scale, was high (average value 8.75 out of 10).

[Tumor markers and immunomodulator substances in ascites--their value as screening and diagnosis parameters]

The object of this study was to determine the known laboratory parameters, tumor markers and immunomodulatory substances in 69 ascites of various etiology, and to test their diagnostic significance. The usual parameters such as protein content, LDH ratio, albumin quotient and albumin gradient, fibronectin, cholesterol and cell count did not reliably differentiate the etiology in each particular case, although the mean values of the various groups differed significantly. Even cytological investigation was negative in 6 out of 29 malignant ascites. Neither were the immunomodulatory substances such as neopterin, beta 2-microglobulin and interleukin-2 receptors suitable for differentiation. In patients with carcinoma of the prostate the values of prostate-specific antigen were significantly increased in ascites. The best separation between benign hepatic or cardiac ascites and malignant ascites was provided by ferritin (sensitivity 97%, specificity 100%). The values in benign hepatic or cardiac ascites were lower than 150 ng/ml and those in malignant ascites higher than 170 ng/ml.