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D Wolk

Publications and source records attributed to D Wolk.

5 recordsLinked to original sources
PubMed2001

Principles of molecular microbiology testing methods.

Molecular testing methods have the potential to replace many conventional microbiology laboratory assays. Recent refinements in technology have resulted in more user-friendly testing platforms. These platforms are automated and have lowered risks for contamination, decreased costs, and are faster than older platforms. The success of these technologies depends on their successful application to patient care. Quality issues include appropriate specimens for analysis, performance characteristics of different analytical methods, optimal specimen processing, the effects of PCR inhibitors, and false-positive results caused by contaminating nucleic acids. Quality control guidelines for molecular microbiologic diagnostic assays are in their infancy and require further development. Additionally, the problem of "too much" sensitivity (brought on by the extreme sensitivity of these techniques coupled with the potential presence of small numbers of pathogenic organisms in asymptomatic individuals) should be considered. Potential problems when monitoring therapy (because molecular detection techniques do not generally have the ability to determine whether an organism is dead or alive) can also occur. Cost-effective test use, pathogen- or disease-targeted algorithms, and standardized methods will be necessary for the true value of these technologies to be realized. This is especially important, because, unlike traditional culture methods, most molecular microbiology methods are pathogen-specific. Clinicians familiar with the reasons why "pan-culture" (i.e., requesting all culture possibilities at once) is inadvisable should not use the same irrational approach when requesting molecular tests. The clinical usefulness of molecular testing will be maximized as targeted algorithms are developed and an understanding of molecular test ordering patterns is realized. Laboratory technicians and physicians must continue to apply and combine theories of traditional microbiology, clinical chemistry, and general medicine to the understanding and application of molecular diagnostics.

Base Sequence↗
PubMed1999

A study of 9-nitrocamptothecin (RFS-2000) in patients with advanced pancreatic cancer.

This ongoing study evaluates the efficacy of oral 9-nitrocamptothecin (9NC), or RFS-2000, in the treatment of advanced pancreatic cancer. Patients received 9NC orally for 5 days/week; 8 weeks of therapy is required to achieve minimum effective dose. Starting dose was 1.5 mg/m2/day, with adjustments made as necessary. Patients were analyzed for changes in tumor size by CT scan, changes in serum CA 19-9 tumor marker levels, quality of life, and survival. 107 consecutive patients with advanced adenocarcinoma of the pancreas were enrolled before November 3, 1997. Of this group, 47 patients did not receive the minimum 2 courses of treatment necessary to induce response, leaving 60 evaluable patients. Primary dose-limiting toxicities were myelosuppression and interstitial cystitis. No deaths were attributed to 9NC. Median survival was 6.5 months for the 107 total patients and 8.7 months for the 60 evaluable patients, with one patient surviving at 44+ months. Of the 60 evaluable patients, 31.7% were responders (median survival 18.6 months; range 6.5-44.7+ months), 31.7% were stable (median survival 9.7 months), and 36.6% were non-responders (median survival 6.8 months). Fifty-seven previously untreated patients had a median survival of 7.3 months compared to 4.7 months for the 50 previously treated patients. Thirty-three patients who failed gemcitabine therapy prior to 9NC treatment had a median survival of 4.7 months. 9NC is safe and efficacious as first-line therapy for the treatment of advanced pancreatic cancer. It also shows some modest success as second-line therapy in treating gemcitabine failures.

Adult↗
PubMed1996

Semirigid instrumentation in the management of lumbar spinal conditions combined with circumferential fusion. A multicenter study.

STUDY DESIGN: Patients with the diagnosis of degenerative disc conditions or spondylolisthesis undergoing circumferential fusion with posterior pedicle screw fixation using a semirigid rod were reviewed. OBJECTIVES: To determine the effectiveness of this approach in achieving a spinal fusion and satisfactory clinical outcome, and to determine the complications associated with the procedure. SUMMARY OF BACKGROUND DATA: The use of instrumentation to stabilize the lumbar motion segments and thereby enhance the fusion rate has been proposed in a number of studies. Semirigid fixation was believed to be effective in achieving these objectives without concern for stress-shielding, which was suggested by some authors using rigid fixation systems. METHODS: Patients who required spinal fusion with anterior and posterior approaches because of specific lumbar pathology or previous surgeries were selected. The surgery consisted of an anterior interbody fusion using allograft, followed by a posterolateral fusion and pedicle screw fixation. Fusion was determined by continuity of trabecular bridging, and outcomes were determined by pain reduction and return to previous levels of activity. Fusion was considered solid if the two posterolateral areas were fused (Zones one and two), if the anterior interbody area was fused (Zone three), or if all three zones were fused. Complications were documented during and after surgery. RESULTS: Sixty-two percent of patients had previous surgery with 25% of these patients having a diagnosis of pseudarthrosis. Fifty-five percent of patients had two or more levels fused, and 43% were heavy smokers. Ninety-seven percent of patients had successful fusions. Pain was significantly reduced on a pain analogue scale from 7.1 to 2.1 in the back and from 5.8 to 1.5 in the leg (p < 0.006 and 0.0001, respectively). Fifty-nine percent of patients returned to their previous level of activity, and 18% returned to lighter work or job retraining, for a total of 77% returning to the same or lighter levels of activity. Complications included metal failure, 4.9%; neurologic deficit, 1.2%; deep infection, 1.2%; deep venous thrombosis, 4.9%; and vascular injury, 2.4%. Fatal pulmonary embolus occurred in one patient. CONCLUSION: This technique produces a satisfactory fusion rate (97%) and a good clinical outcome based on pain reduction and return to a satisfactory level of activity (77%). It is associated with few, but significant, complications that compare well with other reported series in a difficult group of patients. This procedure should be reserved for patients who are considered to be at high risk for not achieving spinal fusion.

Adolescent↗
PubMed1981

Chemotherapy for head and neck cancer relapsing after radiotherapy.

Thirty-nine patients (28 men and 11 women, ages 43 to 83 years) with advanced head and neck epidermoid carcinoma (33 had relapsed from previous radiotherapy) were treated with a three-day bleomycin administration (30 by continuous intravenous infusion and nine by subcutaneous route) followed on the fifth day by intravenous administration of cyclophosphamide + methotrexate + 5-fluorouracil (Bleo-CMF). This drug schedule was based on the cell cycle synchrony principle. Twenty-one of 39 patients (54%) responded (seven complete, 14 partial remission) lasting from 4 to 20 months. The median duration of survival for complete remission, partial remission, and disease progression was 15, ten, and four months, respectively. The Bleo-CMF was well tolerated with minimal toxicity. The effectiveness of this regimen in previously irradiated patients compels us to pursue its application in a randomized study as an adjuvant for Stages III and IV head and neck cancer following maximum eradication of the local disease by surgery and/or radiotherapy.

Adult↗