The role of the Back Rx exercise program in diskogenic low back pain: a prospective randomized trial

OBJECTIVE: To determine the efficacy of the Back Rx program in patients with diskogenic low back pain (LBP). DESIGN: Prospective, randomized study. SETTING: Outpatient setting of a major university teaching hospital. PARTICIPANTS: Subjects with LBP greater than leg pain for at least 3 months duration and magnetic resonance imaging evidence of disk pathology. Fifty of 87 eligible patients consented and were randomized into age- and sex-matched groups. INTERVENTIONS: Group I participated in the Back Rx program for 15 minutes a day, 3 times a week. All patients, from both groups, received celecoxib (200 mg) and hydrocodone (5 mg) with acetaminophen (500 mg) as needed, and wore a lumbar cryobrace for 15 minutes before bedtime. MAIN OUTCOME MEASURES: Roland-Morris Disability Questionnaire score, numeric pain rating score, patient satisfaction score, measured forward flexion, use of celecoxib, hydrocodone, and acetaminophen, time off work, and rate of symptom recurrence. RESULTS: At minimal 12-month follow-up, 70% of group I reported over 50% pain reduction with good or better patient satisfaction, compared with 33% in group II (P=.001). Average daily hydrocodone and acetaminophen use and time off work were less for group I (all, P<.05). Recurrence of symptoms at the end of the year was less for group I (P=.001). CONCLUSIONS: Back Rx exercises, combined with use of a lumbar cryobrace and oral medications, yielded superior therapeutic results than with use of medications and cryobrace alone. Also significant was the reduced rate of recurrence in these patients.     

From external to internal auditory canal: surgical anatomy by an exclusive endoscopic approach

Surgical approaches to the inner ear and internal auditory canal (IAC) are well known and well documented. The objective of this study is to analyze the morphology, and surgical and anatomic findings of an exclusive endoscopic transcanal approach (EETA) to the IAC. Cadaveric dissections were performed on 11 temporal bones, approaching the internal auditory meatus directly through the external ear canal and avoiding mastoidectomy. In all cases, it was possible to dissect the internal carotid artery and jugular bulb with a 0° endoscope, and with good control of these two structures. The medial wall of the bony labyrinth guaranteed good landmarks for IAC dissection, such as the spherical recess, and the labyrinthine tract of the facial nerve. The IAC can be thoroughly visualized in the cadaver using EETA, avoiding mastoidectomy, extensive temporal bone tissue removal and external incisions. Clinically based reports will be required in future to strengthen our preliminary results.     

Clinical Electrophysiologic Assessment of Ulnar Nerve Transposition in Tuberculoid Leprosy

Ulnar nerve transposition was accomplished in 24 tuberculoid leprotic patients, making a total of 27 operations. Results were assessed clinically and electrophysiologically, pre- and postoperatively. and compared with a control group of 30 patients. Excellent results were obtained in early cases with minimal electromyographic changes. Late cases did not improve after surgery.     

Knee kinematics of high-flexion activities of daily living performed by male Muslims in the Middle East

Full flexion is critical for total knee arthroplasty (TKA) patients in the Middle East, where daily activities require a high range of motion in the lower limb. This study aimed to increase understanding of the knee kinematics of normal Muslim subjects during high-flexion activities of daily living, such as kneeling, Muslim prayer, sitting cross-legged, and squatting. The early postoperative kinematics for a select group of Muslim, high-flexion TKA patients are also reported. Mean curves were compared between the normal group and the TKA group. During kneeling, the average maximum flexion was 141.6° for the normal group and 140.2° for the TKA group. The normal group's maximum and minimum knee angles (flexion, abduction, external rotation) were reported and, with the exception of maximum extension, were not significantly different from the TKA group, despite short postoperative times.     

Postinfectious glomerulonephritis in the elderly

Postinfectious glomerulonephritis (PIGN) is primarily a childhood disease that occurs after an upper respiratory tract infection or impetigo; its occurrence in older patients is not well characterized. Here, we report 109 cases of PIGN in patients ≥65 years old diagnosed by renal biopsy. The male to female ratio was 2.8:1. An immunocompromised background was present in 61%, most commonly diabetes or malignancy. The most common site of infection was skin, followed by pneumonia and urinary tract infection. The most common causative agent was staphylococcus (46%) followed by streptococcus (16%) and unusual gram-negative organisms. Hypocomplementemia was present in 72%. The mean peak serum creatinine was 5.1 mg/dl, and 46% of patients required acute dialysis. The most common light microscopic patterns were diffuse (53%), focal (28%), and mesangial (13%) proliferative glomerulonephritis. IgA-dominant PIGN occurred in 17%. Of the 72 patients with ≥3 months of follow-up (mean, 29 months), 22% achieved complete recovery, 44% had persistent renal dysfunction, and 33% progressed to ESRD. The presence of diabetes, higher creatinine at biopsy, dialysis at presentation, the presence of diabetic glomerulosclerosis, and greater tubular atrophy and interstitial fibrosis predicted ESRD. In summary, the epidemiology of PIGN is shifting as the population ages. Older men and patients with diabetes or malignancy are particularly at risk, and the sites of infection and causative organisms differ from the typical childhood disease. Prognosis for these older patients is poor, with fewer than 25% recovering full renal function.     

Functional polycystin-1 dosage governs autosomal dominant polycystic kidney disease severity

Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations to PKD1 or PKD2, triggering progressive cystogenesis and typically leading to end-stage renal disease in midlife. The phenotypic spectrum, however, ranges from in utero onset to adequate renal function at old age. Recent patient data suggest that the disease is dosage dependent, where incompletely penetrant alleles influence disease severity. Here, we have developed a knockin mouse model matching a likely disease variant, PKD1 p.R3277C (RC), and have proved that its functionally hypomorphic nature modifies the ADPKD phenotype. While Pkd1^+/null mice are normal, Pkd1^RC/null mice have rapidly progressive disease, and Pkd1^RC/RC animals develop gradual cystogenesis. These models effectively mimic the pathophysiological features of in utero–onset and typical ADPKD, respectively, correlating the level of functional Pkd1 product with disease severity, highlighting the dosage dependence of cystogenesis. Additionally, molecular analyses identified p.R3277C as a temperature-sensitive folding/trafficking mutant, and length defects in collecting duct primary cilia, the organelle central to PKD pathogenesis, were clearly detected for the first time to our knowledge in PKD1. Altogether, this study highlights the role that in trans variants at the disease locus can play in phenotypic modification of dominant diseases and provides a truly orthologous PKD1 model, optimal for therapeutic testing.     

An Efficient Sampling Method for Regression-Based Polynomial Chaos Expansion

The polynomial chaos expansion (PCE) is an efficient numerical method for performing a reliability analysis. It relates the output of a nonlinear system with the uncertainty in its input parameters using a multidimensional polynomial approximation (the so-called PCE). Numerically, such an approximation can be obtained by using a regression method with a suitable design of experiments. The cost of this approximation depends on the size of the design of experiments. If the design of experiments is large and the system is modeled with a computationally expensive FEA (Finite Element Analysis) model, the PCE approximation becomes unfeasible. The aim of this work is to propose an algorithm that generates efficiently a design of experiments of a size defined by the user, in order to make the PCE approximation computationally feasible. It is an optimization algorithm that seeks to find the best design of experiments in the D-optimal sense for the PCE. This algorithm is a coupling between genetic algorithms and the Fedorov exchange algorithm. The efficiency of our approach in terms of accuracy and computational time reduction is compared with other existing methods in the case of analytical functions and finite element based functions.