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Biomedical subjects

Richard Stern

Publications and source records attributed to Richard Stern.

At least 19 recordsLinked to original sources
PubMed2006

Simultaneous multidopant investigation of rare-earth-doped optical fibers by an ion microprobe.

The relative distribution of five elements present in the core area of several optical fiber samples has been obtained by utilizing nanoscale-secondary ion mass spectrometry. A strong correlation between the rare-earth (RE) ion and aluminum was observed, consistent with aluminum's improving the solubility of the RE ion. The central dip in distribution was less severe than that observed for germanium, characteristic of the collapse process during fabrication of the fiber preform.

Journal Article↗
PubMed2006

Design of the Primary Prevention Parameters Evaluation (PREPARE) trial of implantable cardioverter defibrillators to reduce patient morbidity [NCT00279279].

BACKGROUND: Implantable Cardioverter Defibrillator (ICD) therapy has been proven to be beneficial and efficacious for the treatment of serious ventricular tachyarrhythmias in primary prevention patients. However, primary prevention patients appear to have a lower incidence of ventricular arrhythmias in comparison to secondary prevention patients and consequently likely experience a higher proportion of detections due to supraventricular arrhythmias. Recent trials have demonstrated that strategic and specific programming choices reduce the number of inappropriate shocks and that anti-tachycardia pacing (ATP) is an effective alternative to shock therapy for many sustained ventricular arrhythmias. METHODS: The Primary Prevention Parameters Evaluation (PREPARE) study is a multi-center cohort study, evaluating the efficacy of a pre-specified strategic profile of VT/VF detection and therapy settings in 700 primary prevention patients in an effort to safely reduce the number of shock therapies delivered. The patients, both with and without cardiac resynchronization therapy, are compared to a well-qualified set (n = 691) of historical controls derived from the MIRACLE ICD and EMPIRIC trials. This manuscript describes the design of the PREPARE study. The study results, to be presented separately, will characterize the efficacy of this programming set (PREPARE) compared with physician-tailored programming (MIRACLE ICD and EMPIRIC).

Journal Article↗
PubMed2006

Suction drainage culture as a guide to effectively treat musculoskeletal infection.

Following surgery for musculoskeletal infection, a positive suction drainage culture (SDC) is consistent with persistent sepsis. Our objective was to determine the effect of a negative SDC obtained in subsequent operations on the outcome of a musculoskeletal infection. 99 patients were prospectively enrolled, all treated surgically for musculoskeletal infection utilizing suction drainage and appropriate antimicrobial therapy. Surgery consisted of irrigation, debridement, and prosthetic exchange or implant removal. SDC was considered negative if all bottles resulted in negative cultures. Following SDC results, patients were placed into 1 of 2 treatment groups: 1) Negative SDC, and no new operation; or 2) Positive SDC, and new operation(s) until SDC was negative. Antibiotic therapy ranged from 6-12 weeks (osteomyelitis) to 10-21 d (soft tissue). Both groups were similar with regard to baseline characteristics. Cure was obtained in 91.8% of patients (56/61) in group 1 and 91.6% of patients (22/24) in group 2. Similar results were obtained in patients with an infection in the presence of an implant. In conclusion, a negative SDC following surgery for a musculoskeletal infection is a strong indication of eventual outcome.

Anti-Bacterial Agents↗
PubMed2005

Upper extremity fractures in the elderly: consequences on utilization of rehabilitation care.

BACKGROUND AND AIMS: While hip fractures represent the most dramatic consequence of osteoporosis, fractures of the humerus, forearm and wrist account for one-third of the total incidence of fractures due to osteoporosis in the older population. The aim of this retrospective cohort study was to evaluate rehabilitation care utilization and associated factors in elderly individuals with upper limb fracture. METHODS: Over two years, 667 patients 65 years of age or older were studied, who presented to the emergency department either from their private homes or nursing homes with an upper extremity fracture. The following outcome variables were collected: gender; age; residence; location of fracture; treatment; discharge destination; length of hospitalization; length of stay in a rehabilitation facility; and ultimate place of habitation after the event. RESULTS: The most frequent sites of fracture were distal radius (37.2%) and proximal humerus (29.1%). Two-thirds of the patients were treated non-operatively. Inpatient rehabilitation care was necessary for 248 patients (37.2%; length of stay, 46 days). Factors associated with increased care included older age (> or = 80 years), coming from private home, sustaining two fractures, fractures of the humerus, and operative treatment. Six percent of the patients required permanent nursing home care. CONCLUSIONS: Upper extremity fractures in older people often require prolonged hospitalization and therefore account for considerable health care costs. Reasons are more related to advanced age and living conditions than to particular injury or treatment.

Accidental Falls↗
PubMed2005

Control of severe hemorrhage using C-clamp and arterial embolization in hemodynamically unstable patients with pelvic ring disruption.

INTRODUCTION: Hemorrhage is the leading cause of death in patients with a pelvic fracture. The majority of blood loss derives from injured retroperitoneal veins and broad cancellous bone surfaces. The emergency management of multiply injured patients with pelvic ring disruption and severe hemorrhage remains controversial. Although it is well accepted that the displaced pelvic ring injury must be rapidly reduced and stabilized, the methods by which control of hemorrhagic shock is achieved remain under discussion. It has been proposed to exclusively use external pelvic ring stabilization for control of hemorrhage by producing a 'tamponade effect' of the pelvis. However, the frequency of clinically important arterial bleeding after external fixation of the pelvic ring remains unclear. We therefore undertook this retrospective review to attempt to answer this one important question: How frequently is arterial embolization necessary to control hemorrhage and restore hemodynamic stability after external pelvic ring fixation? MATERIALS AND METHODS: We performed a retrospective review of 55 consecutive patients who presented with unstable types B and C pelvic ring fractures. Those patients designated as being in hemorrhagic shock (defined as a systolic blood pressure less than 90 mmHg after receiving 2 L of intravenous crystalloid) were treated by application of the pelvic C-clamp. Patients who remained in hemorrhagic shock, or were determined to be in severe shock (defined as mandatory catecholamines or more than 12 blood transfusions over 2 h), underwent therapeutic angiography within 24 h in order to control bleeding. RESULTS: Fourteen patients were identified as being hemodynamically unstable (ISS 30.1 +/- 11.3 points) and were treated with a C-clamp. In those patients with persistent hemodynamic instability, arterial embolization was performed. After C-clamp application, 5 of 14 patients required therapeutic angiography to control bleeding. Two patients died, one from multiple sources of bleeding and the other from an open pelvic fracture (total mortality 2/14, 14%). CONCLUSIONS: Although the C-clamp is effective in controlling hemorrhage, one must be aware of the need for arterial embolization to restore hemodynamic stability in a select subgroup of patients.

Adolescent↗
PubMed2005

The inhibition of neutrophil antibacterial activity by ultra-high molecular weight polyethylene particles.

Following infection, bacterial killing by polymorphonuclear leukocytes (neutrophils) is the main host defense against bacteria. Our hypothesis is that particles of ultra-high molecular weight polyethylene (UHMWP) may impair local neutrophil function and consequently reduce neutrophil bacterial killing. To determine how the in vitro phagocytic-bactericidal activity of neutrophils was affected by exposure to wear particles, tests were run comparing the effects of different particle composition, and different concentrations and sizes of UHMWP particles. There was a significant correlation between the number of particles and the decrease in neutrophil bactericidal activity (p<0.01), and the greatest effect was obtained with a concentration of 10(7) UHMWP/ml. There was a significant decrease in neutrophil bactericidal activity by incubation with particles of 0.1-5 microm (p<0.01), but not with larger size. The results suggest that neutrophil functional defects triggered by the presence of UHMWP particles may potentially contribute to the susceptibility of loose implants to bacterial infections.

Biocompatible Materials↗
PubMed2004

Value of preoperative investigations in diagnosing prosthetic joint infection: retrospective cohort study and literature review.

The diagnosis of a prosthetic joint infection is difficult, but crucial for appropriate treatment. Scintigraphy with specific markers for infection (labelled white cells or immunoglobulin-G) has been reported as a more reliable diagnostic tool than clinical assessment (fever, fistula), laboratory studies (polynuclear neutrophil count, erythrocyte rate sedimentation, and C-reactive protein), and preoperative aspiration. In the first part of this study, we retrospectively reviewed 230 patients admitted with a suspected prosthetic joint infection, and examined the validity of the different diagnostic tools for the group as a whole and for subgroups according to the Coventry classification. In the second part, we reviewed 35 articles about preoperative evaluation of infection in prosthetic joints and compared them to our findings. Our study indicates that C-reactive protein and joint aspiration are the most useful tools to diagnose prosthetic joint infection even in situations of chronic infection (Coventry type II).

Adult↗
PubMed2004

High versus standard dose vancomycin for osteomyelitis.

It is important to identify the optimal dosage and best method of infusion of parenteral vancomycin to be used over a several week period for the treatment of osteomyelitis. A retrospective study was undertaken to compare a high dose vancomycin treatment (HD: 40 mg/kg/d) with a standard dose treatment (SD: 20 mg/kg/d), and also to compare the modality of infusion using either intermittent vancomycin infusion (IVI) or continuous vancomycin infusion (CVI). 89 patients with Gram-positive cocci osteomyelitis requiring vancomycin treatment were followed, and the outcome and therapeutic safety were compared. There were significantly more adverse drug reactions (acute renal failure) in the IVI subgroup (HD-IVI vs SD-IVI, p-value 0.007). No cases of renal failure were found in the HD-CVI subgroup. The best outcome was found in the subgroup of patients who received HD-CVI (HD-CVI vs SD-IVI, overall log rank p-value 0.02). HD-CVI treatment appears to provide an improved outcome with fewer adverse drug reactions.

Aged↗
PubMed2004

The value of bacterial culture during clean orthopedic surgery: a prospective study of 1,036 patients.

OBJECTIVE: To determine whether bacterial cultures of the wounds of patients undergoing clean orthopedic surgery would help predict infection. METHODS: During 1 year, 1,256 cultures were performed for 1,102 patients who underwent clean orthopedic surgery. Results were analyzed to evaluate their ability to predict postoperative infection. RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of the cultures were 38%, 92%, 7%, and 99%, respectively. CONCLUSIONS: Cultures performed during clean orthopedic surgery were not useful for predicting postoperative infection.

Adolescent↗
PubMed2004

Anakinra: an inhibitor of IL-1 for the treatment of rheumatoid arthritis.

Anakinra (Amgen, Inc.) is a specific receptor antagonist of IL-1 that differs from naturally occurring IL-1 receptor antagonist by the presence of a methionine group. Anakinra has been shown to be of benefit in patients with active rheumatoid arthritis, either when given alone or in combination with methotrexate, as assessed by improvement in clinical signs and symptoms, decreased radiographic progression and improvement in patient function, pain and fatigue, although it appears to be effective in fewer patients than anti-TNF agents. It has a favourable safety profile as demonstrated in clinical trials. The physician and patient must be cognizant of serious infectious episodes. Many of the rare side effects seen with TNF blockers, such as tuberculosis, other opportunistic infections, worsening of congestive heart failure and the development of demyelinating disease, have not been seen in patients treated with anakinra. Anakinra should not be given in combination with anti-TNF agents.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2004

Infliximab dose and clinical status: results of 2 studies in 1642 patients with rheumatoid arthritis.

OBJECTIVE: Infliximab is an effective anti-tumor necrosis factor (TNF) agent widely used in the treatment of rheumatoid arthritis (RA). Initially recommended at a dose of 3 mg/kg, subsequent label revisions allowed doses up to 10 mg/kg or at 4-week intervals rather than the originally suggested 8-week intervals, if clinically indicated. The doses used have implications for efficacy and costs, but no data exist for actual dose used in the US. This study evaluates the dosage and rates of increase in infliximab-treated patients with RA. METHODS: Study 1: Review of patient charts and infusion records for 394 RA patients from 2 large rheumatology practices comprising 15 rheumatologists in Dallas, Texas. Study 2: Survey of 1324 RA patients using infliximab participating in a longitudinal study of RA outcomes. Patients completed a detailed questionnaire about clinical status and infliximab use. RESULTS: The results of the 2 studies were similar: the average infliximab dose was 5 mg/kg, increasing most rapidly until the end of the first years, after which the increase was slowed. Increases > 3 mg/kg occurred in 61% of patients in Study 1 and 56% in Study 2. The 8-week treatment interval was almost universally used, and more than 95% of infusions occurred in this interval. The most common reason for increase in dose was insufficient response. Among patients who completed 4 infusions, 75% remained on therapy at 2 years after infliximab start. The average improvement in Health Assessment Questionnaire disability score was 0.28. CONCLUSION: Infliximab dose increases are common, particularly during the first year of treatment. The average dose is 5 mg/kg. Seventy-five percent of patients continue using infliximab 2 years after treatment onset.

Antibodies, Monoclonal↗
PubMed2003

Leflunomide use during the first 33 months after food and drug administration approval: experience with a national cohort of 3,325 patients.

OBJECTIVE: To describe leflunomide (LEF) use in a national cohort of 3,325 veterans. METHODS: Prescriptions for LEF and 9 disease-modifying antirheumatic drugs written between October 1998 and June 2001 at all Veterans Affairs (VA) medical centers were obtained from VA national databases. RESULTS: LEF was initiated with a loading dose of 100 mg daily for 3 days in 61% of patients, and 42% of patients discontinued LEF. LEF was more likely to be discontinued if a 3-day 100-mg loading dose was prescribed, patients were younger than 44 years or older than 75 years, or reported an annual family income <$60,000. Review of medical records of 291 discontinuers revealed that the most common reasons for discontinuation were inefficacy (30%), gastrointestinal symptoms (29%), medication noncompliance or lost to followup (14%), and elevated liver enzymes (5%). CONCLUSION: LEF is relatively safe in clinical practice. The VA's national databases provide an excellent, inexpensive resource for postmarketing evaluation of rheumatologic medications.

Adult↗
PubMed2003

Effect of vancomycin therapy for osteomyelitis on colonization by methicillin-resistant Staphylococcus aureus: lack of emergence of glycopeptide resistance.

BACKGROUND: In treating orthopedic infections, the long-term impact of vancomycin therapy on colonization by methicillin-resistant Staphylococcus aureus (MRSA) and the emergence of vancomycin-intermediate S. aureus is unknown. DESIGN: Prospective surveillance of the effect of long-term vancomycin therapy on colonization by MRSA and the emergence of vancomycin-intermediate S. aureus. METHODS: Thirty-four patients with MRSA osteomyelitis that was microbiologically documented were longitudinally observed for the emergence of vancomycin-intermediate S. aureus at 3 body sites (wound, anterior nares, and groin) during the initial period of vancomycin therapy and at the 2-month follow-up. Twenty patients received the standard dose (20 mg/kg/d) for 34 +/- 6 days and 14 patients received a high dose (40 mg/kg/d) of vancomycin for 37 +/- 9 days. RESULTS: During vancomycin treatment, global MRSA carriage (all body sites) fell from 100% to 25% in the group of patients receiving the standard dose of vancomycin, and from 100% to 40% in the group receiving the high dose. During the 2-month follow-up period after vancomycin therapy, global MRSA carriage increased from 25% to 55% in the group receiving the standard dose and decreased from 43% to 36% in the group receiving the high dose. CONCLUSION: Therapy with a high dose of vancomycin contributes to the sustained eradication of MRSA carriage without promoting the emergence of glycopeptide resistance.

Adult↗