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Biomedical subjects

F Rasool

Publications and source records attributed to F Rasool.

4 recordsLinked to original sources

The role of apoptosis, proliferation, and the Bcl-2-related proteins in the myelodysplastic syndromes and acute myeloid leukemia secondary to MDS.

Bone marrow CD34(+) cell apoptosis (annexin V), proliferation (Ki-67), and Bcl-2-related protein expression was evaluated by flow cytometry in 102 patients with myelodysplastic syndrome (MDS) and acute myeloid leukemia secondary to MDS (MDS-AML) and in 30 normal donors (NBM). Apoptosis was significantly increased in refractory anemia (RA)/RA with ringed sideroblasts (RARS) (56.9% [20.4%-93.6%]) and refractory anemia with excess blasts (RAEB) (51.2% [25.2%-76. 6%]) compared with NBM (16.7% [3.4%-35.3%], P <.0001). In RA/RARS, apoptosis always exceeded proliferation (Ki-67-positivity, 26.1% [9.5%-47.8%]; apoptosis:proliferation ratio 2.08 [1.15-3.63]); whereas in RAEB, this ratio equalized (1.14 [0.93-2.08]) due to increased proliferation (40.4% [22%-69.5%]). Progression to RAEB in transformation (RAEB-t)/MDS-AML was associated with a significant reduction in apoptosis (22.3% [2.1%-53.2%]; P <.0001) and proliferation (16.8% [1.9%-75.8%); P =.04; ratio 1.69 [0.16-12.21]). Pro-apoptotic (Bax/Bad) versus anti-apoptotic (Bcl-2/Bcl-X) Bcl-2-related protein ratios were increased in RA/RARS compared with NBM (2.57 [1.93-9.42] versus 1.89 [0.65-4.1]; P =.06), whereas disease progression was associated with significantly reduced ratios (1.16 [0.06-3.32]; P <.0001) due primarily to increased Bcl-2 expression. Apoptosis and Bax/Bad:Bcl-2/Bcl-X ratio were inversely correlated with both International Prognostic Scoring System score and cytogenetic risk group; highest levels observed in patients with low score and/or good risk cytogenetics. There was a trend toward an association between Bcl-2-related protein expression and apoptosis (P =.07). This study indicates that MDS progression arises through multiple hits that alter levels of CD34(+) cell apoptosis and proliferation. Early disease is associated with excessive apoptosis and elevated ratio of apoptosis to proliferation. Increased proliferative rates are observed in RAEB, whereas leukemic transformation arises through inhibition of apoptosis rather than excessive cell growth. Although disease progression is accompanied by a fall in pro-apoptotic versus anti-apoptotic Bcl-2-related protein ratios, heterogeneity in patterns of protein expression indicates that factors additional to Bcl-2 family members play a role in the deregulated apoptosis in MDS. (Blood. 2000;96:3932-3938)

Acute Disease↗

Clinical and radiographic evaluation of early loaded free-standing dental implants with various coatings in beagle dogs.

STATEMENT OF PROBLEM: Immediate loading of implants may be a predictable treatment alternative when cross-arch stabilization with a fixed provisional is observed. PURPOSE: This study investigated the effect of immediate masticatory loading on the stability of single-standing dental implants with 4 different surfaces. MATERIAL AND METHODS: A total of 40 solid screw implants (diameter 3.3 mm, length 8 mm) were placed in the mandibles of 4 beagle dogs. Test groups included 3 hydroxyapatite (HA) coatings of titanium plasma-sprayed (TPS) implants. Implants with TPS alone served as control. Gold crowns were inserted 2 days after implant placement and the dogs were immediately put on a hard food diet. Implants were followed for 6 months after loading. Clinical and radiographic assessments of implants were performed at time of crown insertion (baseline) and after 1, 3, and 6 months of loading. The Periotest instrument was used for mobility measurements and radiographs were obtained for evaluation of peri-implant radiolucency and measurement of crestal bone changes. RESULTS: Of 40 implants, 39 displayed no discernible mobility, corresponding to successful clinical function. Peri-implant radiolucencies were absent for all but the 1 mobile implant. The reduction in crestal bone levels adjacent to the implants between baseline and 6 months was statistically significant (P <.0001). No statistically significant differences in crestal bone level changes over time were found between the various coatings demonstrating the absence of a treatment effect initiated by the surface coatings. CONCLUSION: In this study in beagle dogs, immediate masticatory loading of single-standing dental implants did not jeopardize tissue integration, provided the implants had excellent primary stability.

Analysis of Variance↗

Evidence-based esthetic dentistry.

Evidence-based clinical practice integrates the best available evidence with clinical expertise. This article presents a clinical case scenario and, using a four-step, evidence-based approach, demonstrates how to (1) ask an evidence-based question; (2) search MEDLINE for the best evidence; (3) critically appraise the evidence; and (4) apply the evidence to the patient. The procedure is demonstrated with the sample question, Does bleaching of bonded porcelain veneers increase marginal leakage? A MEDLINE search strategy was developed for synonyms of the key words that best identify the problem, the intervention, and the outcome. The synonyms were combined using the Boolean operator "or" to identify a "sensitive" (i.e., inclusive) universe of 140,000 journal articles. These categories were then combined using the Boolean operator "and" to identify the most "specific" (i.e., exclusive) four articles from among the 140,000. Finally, to find the best evidence, the articles were limited to "humans" and "randomized controlled trials." This identified one article. Critical appraisal of the limited data in this one article indicates that the methods are valid and statistically significant, but because of the methods employed, may not be clinically important. Evidence-based methods take one to the edge of the available information universe in about 15 minutes. The results can be both exhilarating and sobering. They can indicate the depth or limits of available information and suggest gaps in the knowledge-base that require further study. Most importantly, however, the results allow practitioners to communicate incisively and truthfully with patients and to make more informed clinical choices.

Aged↗