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Biomedical subjects

C Frank

Publications and source records attributed to C Frank.

At least 199 records · Page 11Linked to original sources
PubMed1976

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Dental Stress Analysis↗
PubMed1975

Sex differences in preadolescent self-esteem.

It was predicted from the theories of Bardwick that 1) made self-esteem would be greater than female self-esteem only among the older children of the preadolescent sample, 2) reading achievement would correlate with self-esteem for boys in all age groups but only for the younger girls, and 3) individual self-esteem items that showed sex differences would be sex-role related. Data on self-esteem and reading score were collected on 307 urban children in second through sixth grades. Analysis of results confirmed predictions 1 and 3, but not prediction 2. Reading score did not show a significant correlation with self-esteem for girls at any age level tested. Results were discussed in terms of differing sources of male and female self-esteem.

Achievement↗
PubMedDate not supplied

An approach to single trial analysis of event-related potentials based on signal detection theory.

The aim of the present paper was to introduce a single trial analysis to event-related potential measurement in order to illuminate the mechanisms behind an impaired P300 amplitude occurring under certain experimental conditions. For this purpose we applied tools from linear system theory and signal detection theory to single trials in an oddball paradigm in order to estimate the amplitude of the positive deflection around the P300 latency following target and nontarget stimuli. According to the density functions of these amplitude distributions we operationally defined 'P300 absent in target' (P300 amplitude smaller than an individual threshold under target conditions) as well as 'P300 present in nontarget' (amplitude greater than the threshold under nontarget conditions). Our approach appears to be appropriate to differentiate between an overall reduction of single trial event-related potentials and seldom elicited P300s.

Adult↗
PubMedDate not supplied

High capacity substrates as a platform for a DNA probe array genotyping assay.

Colloidal silica particles were deposited on a glass substrate to produce high-capacity porous supports for high-density DNA probe arrays. Porous surfaces were used to increase the addressable surface area and number of probes available for hybridization. Surfaces derived from 70-100 nm size particles deposited in films from 0.15 to 2 microns thick exhibited excellent performance in light-directed oligonucleotide synthesis. Evaluation of these substrates in a genotyping assay is reported.

Colloids↗
PubMedDate not supplied

Medial collateral ligament healing. A multidisciplinary assessment in rabbits.

Medial collateral ligament healing without treatment has been studied in a rabbit model. Complete midsubstance gaps were found to heal by distinct scar formation over time. This healing process was fast since the gap was bridged quickly; however, more subtle changes in appearance of the healing tissue continued for many months. The ligament "scar" was found to be structurally abnormal chemically and mechanically even at long-term followup. A plateau in its improvement suggests that the scar may never approach normal ligament characteristics (without treatment). A baseline of ligament healing by scar formation has been established.

Animals↗
PubMedDate not supplied

Allograft ligament transplantation. A morphological and biochemical evaluation of a medial collateral ligament complex in a rabbit model.

Our purpose in this investigation was to describe and compare several morphological, histological, vascular, and biochemical healing processes of allograft and autograft bone-medial collateral ligament-bone complexes in a rabbit model. Forty-nine animals had their right medial collateral ligament complex replaced with a frozen allograft while 30 separate control animals each received a fresh autograft. Animals were sacrificed at 3, 6, 12, 24, or 48 weeks after transplantation for comparison of grafted with unoperated contralateral control complexes. Results demonstrate some recovery of both allografts and autografts over time. Allografts generally showed slower recovery than autografts with more persistent abnormalities in gross appearances, increased cellularity (corresponding to increased DNA content), and decreased collagen content. Allografts also showed aggressive remodeling of bone at insertions and they remained hypervascular throughout their substance as compared with contralateral controls. Autografts went through similar but less chronic increases in cellularity and DNA concentration with no changes in collagen content. While both types of grafts showed some signs of "healing" and some recovery of control ligament biology, results are also consistent with allograft encasement, infiltration, and at least partial replacement by host tissue. This was particularly true of insertions. Collectively, these results also demonstrate some differences between allografts and autografts in this extraarticular model. The causes, mechanisms, and longer-term consequences of these changes, including defining the qualities of these graft and host tissues, clearly requires further investigation.

Animals↗
PubMedDate not supplied

Prospective evaluation of the McMurray test.

The accuracy and interexaminer reliability of the McMurray test for the diagnosis of meniscal tears were compared with arthroscopic findings in a prospective study of 104 consecutive patients awaiting elective arthroscopy. The only significant McMurray sign found to correlate with meniscal injury was a "thud" elicited on the medial joint line with a medial meniscal tear (P = 0.05) that had a fair interexaminer reliability (kappa = 0.35). The sensitivity of a medial thud was 16%, and the specificity was 98% with a positive predictive value of 83%. Examiner experience had little effect on the accuracy of diagnosis of medial meniscal tears. This study supports the continued but limited emphasis on the McMurray test in the clinical diagnosis of meniscal tears.

Arthroscopy↗
PubMedDate not supplied

The effect of elastic bandages on human knee proprioception in the uninjured population.

Elastic bandages are often used to treat musculoskeletal disorders, even though there is little scientific evidence currently to support this generalized practice. We tested the hypothesis that elastic bandages improve proprioception of the bandaged joint during their use, and that this benefit was more than temporary. The uninjured human knee was used as a model. Fifty-four volunteers (54 knees), aged 22 to 40 years, were asked to identify a prior set joint angle as their knee was passively extended. Each knee was tested without the elastic bandage, immediately after bandage application, after 1 hour of bandage wear, and finally after removal of the bandage. Results showed that elastic bandages significantly improved knee joint proprioception in the uninjured knee during the entire interval of their use (mean decrease in inaccuracy of 1.0 degree, equivalent to 25% improvement, P < 0.05), and that this benefit was lost when the bandage was removed. The magnitude of the improvement, or the potential beneficial effect of the bandage, was inversely related to the participant's inherent knee proprioceptive ability, which was demonstrated in the test group before the initial application of the bandage.

Adult↗
PubMedDate not supplied

Modulation of doxorubicin-induced DNA lesions by verapamil, DMDP and dipyridamole in resistant P388 cell lines.

Lymphoid cell lines resistant to doxorubicin, P388/R, were characterized by: 1) decreased intracellular acumulatin and retention of DOX; 2) decreased amount of DOX-induced DNA lesions; and 3) rapid repair of DOX-induced DNA lesions. Using the highest noncytotoxic concentrations of three modulators; 2 calcium channel blockers, Verapamil (VEP) and DMDP and a nucleoside transport inhibitor, Dipyridamole (DIP), restoration of Doxorubicin (DOX) sensitivity in vitro against P388/R cells was partial; resistance was reduced from approximately 200 to 10 fold, although DOX accumulation in the resistant cells in the presence of the modulators was completely restored. The DNA single-strand break (SSB) level induced by DOX in P388/S cells (1371 +/- 144 rad equivalents) was significantly higher than in P388/R cells (74 +/- 17 rad equivalents). The effects of VEP, DMDP and DIP on the induction of DNA SSBs by DOX in P388/R were different. DMDP and DIP potentiated the DOX-induced DNA SSBs by 30% each and VEP by 15%. Furthermore, while VEP and DIP had no significant effects on the rapid repair of DOX-induced SSBs, no significant repair of DNA lesion was observed in P388/R treated with DMDP at 1.2 microM, a non-cytotoxic concentration. These data indicate that although these modulators can effectively restore the intracellular accumulation and retention of DOX, these conditions although essential are not sufficient for the complete restoration of DOX sensitivity in this highly resistant cll line. The ability of a calcium antagonist, DMDP, to circumvent DOX resistance might be related not only to the modulation of drug retention, but also to the ability to retard the repair of DOX-induced DNA SSBs.

Alkaloids↗