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Biomedical subjects

L Freed

Publications and source records attributed to L Freed.

4 recordsLinked to original sources
PubMed2004

[Engineering and characterization of functional osteochondral replacement tissue].

Extensive osteochondral lesions require repair of the cartilage and underlying bone. We generated osteochondral repair tissue by tissue engineering. Standardized defects, 7 x 5 x 5 mm, were created in femoropatellar grooves of adult rabbits. Engineered cartilage, generated in vitro starting from chondrocytes and a biodegradable scaffold, was implanted using Collagraft as subchondral support. Cell-free implants, defects left empty, and unoperated knee joints served as controls. Explants were characterized morphologically and mechanically. Engineered cartilage implants were superior to cell-free implants and to natural healing of empty defects with respect to the histologic score and Young's modulus of the 6-month repair tissue. These data suggest that engineered cartilage can provide primary stability for the treatment of critical osteochondral defects.

Bone Remodeling↗
PubMed2001

Electrical stimulation for swallowing disorders caused by stroke.

BACKGROUND: An estimated 15 million adults in the United States are affected by dysphagia (difficulty swallowing). Severe dysphagia predisposes to medical complications such as aspiration pneumonia, bronchospasm, dehydration, malnutrition, and asphyxia. These can cause death or increased health care costs from increased severity of illness and prolonged length of stay. Existing modalities for treating dysphagia are generally ineffective, and at best it may take weeks to months to show improvement. One common conventional therapy, application of cold stimulus to the base of the anterior faucial arch, has been reported to be somewhat effective. We describe an alternative treatment consisting of transcutaneous electrical stimulation (ES) applied through electrodes placed on the neck. OBJECTIVE: Compare the effectiveness of ES treatment to thermal-tactile stimulation (TS) treatment in patients with dysphagia caused by stroke and assess the safety of the technique. METHODS: In this controlled study, stroke patients with swallowing disorder were alternately assigned to one of the two treatment groups (TS or ES). Entry criteria included a primary diagnosis of stroke and confirmation of swallowing disorder by modified barium swallow (MBS). TS consisted of touching the base of the anterior faucial arch with a metal probe chilled by immersion in ice. ES was administered with a modified hand-held battery-powered electrical stimulator connected to a pair of electrodes positioned on the neck. Daily treatments of TS or ES lasted 1 hour. Swallow function before and after the treatment regimen was scored from 0 (aspirates own saliva) to 6 (normal swallow) based on substances the patients could swallow during a modified barium swallow. Demographic data were compared with the test and Fisher exact test. Swallow scores were compared with the Mann-Whitney U test and Wilcoxon signed-rank test. RESULTS: The treatment groups were of similar age and gender (p > 0.27), co-morbid conditions (p = 0.0044), and initial swallow score (p = 0.74). Both treatment groups showed improvement in swallow score, but the final swallow scores were higher in the ES group (p > 0.0001). In addition, 98% of ES patients showed some improvement, whereas 27% of TS patients remained at initial swallow score and 11% got worse. These results are based on similar numbers of treatments (average of 5.5 for ES and 6.0 for TS, p = 0.36). CONCLUSIONS: ES appears to be a safe and effective treatment for dysphagia due to stroke and results in better swallow function than conventional TS treatment.

Aged↗
PubMed2000

Regulatory science: a special update from the United States Food and Drug Administration: Preclinical issues and status of investigation of botanical drug products in the United States.

A recent survey was conducted across the therapeutic divisions within the CDER, U.S. FDA regarding the number of submissions related to botanical drug products over the past ten years. The overall number of botanical submissions as expressed in the parenthesis are as follows: 1990 (1), 1991 (4), 1992 (4), 1993 (5), 1994 (6), 1995 (5), 1996 (13), 1997 (16), 1998 (10). In the total of 64 counted, 50 of them are submitted in original IND and the rest (14) in pre-IND format. The therapeutic categories are focused on dermatological and topical (19), anti AIDS/antiviral (12), oncologic (13), neuropharmacologic (8), endocrine and metabolic (3), urologic (2), tobacco (2), and cardio-renal products (1). The regulatory actions taken on these submissions showed that 68% of them are evaluated as safe to proceed for the human trials, while the rest (32%) of submissions required agency's regulatory guidance. Among the submissions that required further guidance, 81% were deficient in preclinical pharmacology/toxicology information and the rest (19%) lacks information in other areas (chemistry, clinical protocols). Following agency's guidance, 93% of the submissions that were put on hold were allowed to proceed. In summary, a total of 94% of all the botanical INDs submitted to the agency were allowed to proceed without additional animal toxicity studies conducted. In conclusion, this survey indicates that the growing public interest in botanical supplements has prompted more formal evaluation of the efficacy/safety claims of these products.

Databases, Factual↗