Current approved options for treating patients with multiple sclerosis

Multiple sclerosis (MS), a neurologic disorder that affects 400,000 persons in the United States, consists of an inflammatory and a neurodegenerative phase. Treatment options now approved by the FDA specifically target the inflammatory phase of MS and include immunomodulators (i.e., interferon betas and glatiramer acetate) and an immunosuppressant, mitoxantrone. This article discusses the methods of monitoring disease progression using disability scales and MRI and reviews the clinical efficacy and tolerability of the FDA-approved therapies. All of the immunomodulators are approved for the treatment of relapsing forms of MS. Only mitoxantrone is approved for the treatment of worsening relapsing-remitting MS, secondary progressive MS, and progressive-relapsing MS. Early treatment with these disease-modifying agents is desirable to reduce the progression of the disease and to limit long-term disability.

Identifying and treating patients with suboptimal responses

Multiple sclerosis (MS) is an immune-mediated neurologic disease in which acute inflammatory events early in the disease course contribute to subsequent neurologic disability. The early relapsing inflammatory phase is followed by a progressive degenerative phase in which the frequency of acute inflammatory attacks diminishes but progressive loss of neurologic function continues. Current immune therapies are most effective in suppressing the acute inflammatory events that characterize the earlier stages of disease. Optimal suppression of these inflammatory events is likely to have the best potential for delaying or preventing loss of axons and decline in neurologic function. In view of these considerations, and because MS is a heterogeneous disease and response to disease-modifying agents (DMA) varies across individuals, it is important to identify suboptimal responders as early as possible to allow therapeutic modification while the opportunity to avert future loss of function remains. At present, no criteria for identifying suboptimal responders have been validated. In January 2004, a group of neurologists from 16 MS centers in the United States met to develop a consensus on criteria for defining suboptimal response for use in compelling clinical situations and to prompt clinical studies to validate the efficacy of these criteria. Consensus criteria included relapse rates of either 1/year or unchanged from pretreatment rates, incomplete recovery from multiple attacks, evolution of polyregional neurologic involvement, recurrent brainstem or spinal cord lesions, and cumulative loss of neurologic function sufficient to disrupt daily activities. The panel then considered the use of mitoxantrone for patients with worsening MS and a suboptimal response to DMA therapy.

Management of pediatric urolithiasis in Pakistan: experience with 1,440 children

PURPOSE

We evaluated the efficacy and safety of different modalities for pediatric urolithiasis in a developing country in 2 eras, namely before and after the advent of minimally invasive surgery.

MATERIALS AND METHODS

We retrospectively reviewed the records of 1,440 children younger than 14 years treated with various modalities during a 14-year period. From 1987 to 1995, 486 and 50 patients were treated with open surgery, and extracorporeal shock wave lithotripsy (ESWL, Dornier Medical Systems, Inc., Marietta, Georgia) and minimally invasive methods, respectively. Between 1996 and 2000, 518 and 386 children were treated with surgery and minimally invasive methods, respectively.

RESULTS

Of the 1,440 children 795 (55.2%) had renal, 198 (13.8%) had ureteral and 447 (31%) had bladder calculi. Of the renal stones 556 (70%), 177 (22%) and 62 (7.8%) were treated with open surgery, ESWL and percutaneous nephrolithotomy, respectively. Of the ureteral calculi 85 (43%), 37 (18.6%) and 76 (38%) were managed by ESWL, ureterorenoscopy and open surgery, respectively. Of the bladder calculi 307 (68%), 77 (17.2%) and 63 (14%) were treated with open vesicolithotomy, transurethral pneumatic cystolithotripsy and ESWL, respectively. The renal stone clearance rate was 98% after open surgery, 84% after ESWL and 68% after percutaneous nephrolithotomy monotherapy at 3 months of followup. Similarly the ureteral stone-free rate was 54% after ESWL and 86.9% after ureterorenoscopy. Of the patients with bladder calculi 48% and 93% become stone-free after ESWL and transurethral pneumatic cystolithotripsy, respectively.

CONCLUSIONS

The use of ESWL, percutaneous nephrolithotomy and ureterorenoscopy has resulted in treating a large number of children with a short hospital stay and early return to school. Open surgery is reserved only for complex stones.

Symptomatic therapy for underrecognized manifestations of multiple sclerosis

The symptoms that affect individuals with MS are diverse and change over time. Addressing symptoms in a multidisciplinary fashion and helping patients address problems as they occur are the major elements of symptom management. Successful management involves treating not only the more readily recognized manifestations of MS but also the less apparent MS features, including fatigue, cognitive loss, mood disturbance, and pain. Management of these symptoms is reviewed.

Laser extraction of entrapped leads

Removing entrapped pacing and defibrillator leads has been greatly simplified by making use of the excimer laser extractor. Sixty-two leads were successfully removed, although where appropriate, portions of the lead remained in place in 10 cases. There were two serious complications, one tear of the superior vena cava during an ICD extraction and one tear of the atrium during an atrial lead extraction. Both were controlled successfully through emergency sternotomy. Although extracting entrapped leads has been much simplified by making use of the laser extractor, the process is not free of serious complications. Those involved in explanting leads should be aware of the outcomes and be prepared for emergent management.

High-energy microwave thermotherapy in patients in urinary retention

PURPOSE

To study the outcome of high-energy transurethral microwave thermotherapy (TUMT) in patients with obstructive benign prostatic hyperplasia (BPH).

PATIENT AND METHODS

Between September 1995 and March 1998, patients presenting with urinary retention secondary to BPH were recruited into the study. Their mean age was 67.2 years (range 50-85 years). The mean catheterization time prior to treatment was 3 months (range 15 days-1 year). Among the 200 patients treated during this period, 30 were high anesthesia risk (American Society of Anesthesiologists Class III/IV). The patients were treated in a single 1-hour session using high-energy (Prostatron 2.5) software, the range of energy transmitted being 111.9 to 214.2 kJ (mean 196.3 kJ). Symptoms were scored according to the International Prostatic Symptom Score (IPSS). The mean prostate volume subjected to TUMT was 59 cc (range 40-149.7 cc). The patients were followed every 3 months with measurements of peak flow rate, postvoiding residual urine volume estimation, and IPSS.

RESULTS

Of the 200 patients, 33 were lost to follow-up, 155 were responsive (catheter free with physiologically acceptable peak flow rate), and 12 (7%) were nonresponsive. Only 4 patients (2%) experienced deterioration in their flow rates during the follow-up period of 2 years. They underwent transurethral resection. High-energy thermotherapy resulted in irritative voiding complaints in 80% of patients for 2 to 4 weeks.

CONCLUSION

The initial results were encouraging, and the 2-year follow-up has shown appreciable sustainability in the treatment outcome, particularly in patients at high anesthesia risk.

[The use of transpedicular system of stabilization in surgical treatment of vertebral column tumors]

The experience of application of the titanium transpedicular systems in 23 patients with the vertebral column (VC) tumor was summarized. In all the patients good VC stability was noted after the operation, what had permitted to conduct their early activization.

Outcome of machine-perfused non-heart-beating donor kidneys, not allocated within the Eurotransplant area

Eleven non-heart-beating (NHB) donor kidneys considered vital during machine perfusion (MP), could not be allocated inside Eurotransplant (ET). With the help of ET, five kidneys were transplanted in Karachi and six in Basel. Our goal was to prove that NHB kidneys successfully passing MP viability tests can be transplanted safely.

METHODS

Donor age, serum creatinine (some post-mortem) and warm ischaemic time were, respectively, (mean and range): 44 (14-70) years, 137 mumol/l, and 44 (9-80) min. Reasons for refusal were: bold ureter (one), suboptimal flush (one), relatively long hypotensive phase (seven), and donor age of 70 years (two). After 8 h of MP, mean lactate dehydrogenase, intrarenal resistance and alpha glutathione S-transferase were (including range): 556 U/l (range 366-819 U/l), 0.86 mmHg/ml per min (0.41-1.15 mmHg/ml per min) and 1188 micrograms/l (575-2677 micrograms/l), respectively. Mean cold ischaemic time was 45 (range 28-72) h.

RESULTS

Two kidneys showed immediate function, and nine showed delayed function. Mean creatinine levels after 1, 3 and 6 months were 295, 200 and 206 mumol/l, respectively. Four patients died for reasons not related to their kidney transplantation.

CONCLUSIONS

We claim that MP can successfully assess viability of NHB donor kidneys. The reluctance to accept MP, and judged vital, NHB donor kidneys is not longer justified.

A modular neural network vector predictor for predictive image coding

In this paper, we present a modular neural network vector predictor that improves the predictive component of a predictive vector quantization (PVQ) scheme. The proposed vector prediction technique consists of five dedicated predictors (experts), where each expert predictor is optimized for a particular class of input vectors. An input vector is classified into one of five classes, based on its directional variances. One expert predictor is optimized for stationary blocks, and each of the other four expert predictors are optimized to predict horizontal, vertical, 45 degrees , and 135 degrees diagonally oriented edge-blocks, respectively. An integrating unit is then used to select or combine the outputs of the experts in order to form the final output of the modular network. Therefore, no side information is transmitted to the receiver about the selected predictor or the integration of the predictors. Experimental results show that the proposed scheme gives an improvement of 1.7 dB over a single multilayer perceptron (MLP) predictor. Furthermore, if the information about the predictor selection is sent to the receiver, the improvement could be up to 3 dB over a single MLP predictor. The perceptual quality of the predicted images is also significantly improved.

Prediction of renal function recovery in obstructive renal failure due to stones

Two hundred and thirty-nine patients with renal and ureteric calculi associated with renal failure were evaluated for recovery potential before definitive surgery. Ultrasonography was carried out pre-operatively in all, followed by percutaneous nephrostomy (PCN) as an initial management before definitive surgery. Diethylene triamine penta acetic acid (DTPA) scan was done in 125 patients after percutaneous nephrostomy, findings of pre- operative DTPA scan were correlated with post-operative drop in serum creatinine. Urine pH, urine Na+, initial diuresis, creatinine clearance and serum creatinine were measured serially after 24 hours and then every week for 6 weeks. Patients were re-evaluated with serum creatinine after 3 months of surgery. Ultrasonography was found to be reliable in predicting future recovery of renal functions in 76.5% cases and true obstruction of shorter duration (F4-group) on DTPA scan in 81.9% cases. Urine pH of 6 or less, post-PCN diuresis and natriuresis were good prognostic indicators. PCN was found to be most reliable method of predicting future recovery of renal function after relief of obstruction with 97.8% accuracy.

Nonlinear vector prediction using feed-forward neural networks

The performance of a classical linear vector predictor is limited by its ability to exploit only the linear correlation between the blocks. However, a nonlinear predictor exploits the higher order correlations among the neighboring blocks, and can predict edge blocks with increased accuracy. We have investigated several neural network architectures that can be used to implement a nonlinear vector predictor, including the multilayer perceptron (MLP), the functional link (FL) network, and the radial basis function (RBF) network. Our experimental results show that a neural network predictor can predict the blocks containing edges with a higher accuracy than a linear predictor.