Influence of schedule and mode of administration on effectiveness of podofilox treatment of papillomas

We investigated the timing of podofilox delivery to see how it correlated with papilloma size. We looked at times ranging from once per week (morning and afternoon) to five times per week (morning and afternoon). We also looked at delivery systems that might enhance the effectiveness of the drug by increasing penetration of the overlying cutaneous horn. These included soaking prior to drug administration, the use of a grooved needle subsequent to drug administration, and the various possible combinations of these techniques. We found that the timing of treatments had relatively little effect on the size of the papillomas. For example, at the end of ten weeks, the geometric mean diameter (GMD) (mm) of the papillomas treated five times per week and induced by a 10(-1) dilution of the virus (group B) was 18. Likewise the GMD (mm) of papillomas treated once per week was 18 (group D). On the other hand, we found that soaking plus the use of a grooved needle plus podofilox resulted in the curing of all lesions induced by a 10(-2) virus dilution and of most induced by the 10(-1) dilution, whereas soak plus podofilox or podofilox alone were not as effective in curing the lesions. Podofilox plus needle approached the soak plus podofilox plus needle in effectiveness. Treatment schedule was not a critical determinant of podofilox effectiveness. Therapeutic benefits were enhanced by hydration of the overlying cutaneous horn and penetration with a grooved needle.     

Using a cost-construction model to assess the cost of educating undergraduate medical students at the University of Texas--Houston Medical School

Spontaneous resolution of deformities after excision of facial skin lesions has been known and used for a long time by plastic surgeons. The resorption mechanism of deformity is based on natural skin expansion, and seems to be directly related to the action of the muscles of facial expression and their skin relations. Natural expansion has been shown to be effective in children. Between 1990 and 1994 excision of skin lesions, including congenital nevi, leading to postoperative deformity of the cheek, labial commissure, nose, eyelid and forehead, was performed on 35 patients, aged from 3 month to 12 years. The average follow-up is 24 months. For 26 patients (74%), natural resorption was observed 4 or 6 weeks later with good aesthetic results. For 6 patients (17%), the deformity persisted 3 or 6 months later, but did not require any further surgery. For 3 patients (9%), a second operation was necessary. Using the skins natural capacity for expansion in the treatment of facial skin defects in children is a method of reconstruction which has already been used for excision in enforced position. The platysma and muscles of facial expression by their action on skin mobilisation, allow natural expansion. A better knowledge of cutaneous biomechanical properties enables plastic surgeons to find an alternative to other classical methods.     

Childhood fibrous dysplasia presenting as blindness: a skull base approach for resection and immediate reconstruction

Fibrous dysplasia is an abnormal fibroosseous process of bone of unknown cause. The incidence of skull involvement varies, painless enlargement being the most common presenting symptom. Change in vision is a rare but recognized finding. We report a 3-year-old boy with extreme fibrous dysplasia involving the skull base, who presented with blindness. He underwent exposure osteotomies of the frontal bones and orbits to provide access for skull base tumor removal. The orbital roofs were reconstructed with microplate-fixed cranial grafts. One and one half years after tumor excision followed by immediate reconstruction, the boy retains facial symmetry, and his ocular function has not deteriorated.     

trans-2-phenylcyclopropylamine is a substrate for and inactivator of horseradish peroxidase

Horseradish peroxidase (HRP) is well known for mediating the electron-transfer oxidation of electron-rich aromatic 'donors' such as phenols and anilines, but has not been described to oxidize aliphatic amines. We here confirm the inability of HRP to oxidize typical aliphatic amines, even those which would exist significantly as free bases at the operative pH. In contrast, trans-2-phenylcyclopropylamine (2-PCPA) is both a substrate (turnover product is cinnamaldehyde) and a time-dependent inactivator of HRP. These activities of 2-PCPA are consistent with either a concerted or rapid sequential one-electron-oxidation/ring-opening to give an intermediate capable of covalent binding to the enzyme. 2-PCPA is the first known example of a simple aliphatic amine which serves as a substrate for HRP under turnover conditions.     

Ratings of the performances of practicing internists by hospital-based registered nurses

PURPOSE: To examine the feasibility and reliability of ratings completed by hospital-based registered nurses of the humanistic qualities, communication skills, and selected aspects of the clinical skills of practicing internists. METHOD: In 1988-1989, registered nurses who worked in the same 175 hospitals as 232 internists with admitting privileges at these hospitals rated the internists' performances. The nurses were selected from medicine floors, specialty floors, and intensive care units and/or critical care units, using lists provided by head nurses. A total of 1,877 rating questionnaires with 13 performance categories were collected (with a mean of 8.01 nurses per internist). The ratings were analyzed to determine measurement characteristics and the relationships of the nurses' demographic characteristics to the ratings. In addition, for each of ten performance categories for 152 of the internists, the average rating each internist received from nurses was compared with the average rating each internist received from peer physicians. Statistical analysis used Pearson correlations, canonical correlations, factor analyses, Student's t-tests, analysis of variance, and stepwise multiple regression. Finally, the internists themselves, including physicians who were not actually rated by the nurses, were asked to complete a brief questionnaire that included questions about their opinions of the use of nurses' ratings. RESULTS: The nurses' ratings correlated moderately strongly with the peer physicians' ratings and had a common structure. However, the nurses' ratings were lower for several humanistic qualities, including respect, integrity, and responsibility, and their ratings were higher for medical knowledge and verbal communications. Across the 13 performance categories, approximately 10-15 ratings from nurses were needed to obtain a reliable assessment of an internist's humanistic qualities and communication skills. Many internists felt that nurses' ratings should be used equally with, or at least as a lesser contribution to, ratings by peer physicians of humanistic qualities and communication skills. CONCLUSION: Nurses' ratings appear to provide a feasible and reliable method of evaluating the internists' communication skills and humanistic qualities, when used in conjunction with ratings by peer physicians.     

Effects of manufacturing defects on the mechanical properties of carbon fibre reinforced polyethersulphone laminates

The effects of defects on the mechanical properties of carbon fibre reinforced polyethersulphone laminates have been measured. The defects studied were cut fibre plies, omission of polymer films and local delamination produced by the inclusion of foreign matter. Of these it was found that only cut plies had a significant detrimental effect on the strength of a laminate. For specimens with two cut plies, the failure stress, tensile, flexural and compressive in the remaining continuous plies was the same as in the defect-free material, provided that the cut plies were widely separated. However the failure stresses were 15–18% lower in the continuous plies in the specimens containing two cut plies which were more closely spaced and in specimens containing four cut plies.     

Structural and Superconducting Property Variations with Nominal Mg Non‐Stoichiometry in MgxB2 and Its Enhancement of Upper Critical Field

By applying a combination of characterisation tools, changes in structural and superconducting properties with nominal Mg non‐stoichiometry in Mg_xB₂ are found. The non‐stoichiometry produces enhanced in‐field critical current densities (J_c's) and upper critical field / irreversibility field (H_c2/H_irr(T)) values. Upper critical fields of ～ 21 T (4.2 K) were obtained in nominal Mg‐deficient samples compared to ～ 17 T (4.2 K) for near‐stoichiometric samples.     

Analytical pyrolysis as a tool for the study of plastic coals

The technique of analytical pyrolysis has been used to characterize 40 similar mid-rank western Kentucky coals of widely differing ASTM Gieseler plasticity. Certain pyrolysis/g.c. variables were shown to correlate well with both ASTM Gieseler and isothermal plasticity. Highly plastic coals were shown to exhibit certain characteristic peaks in the 450 °C pyrogram which were absent in the pyrogram of the non-plastic coals. Two coals, representing the two extremes in plasticity, were selected for further study. After extraction with solvents such as DMF the characteristic peaks were absent in the 450 °C pyrogram of the extraction residue of the highly plastic coal. These peaks were also shown to decrease with increasing severity of air oxidation of the plastic coal. This technique appears to be a useful tool for the analysis of mid-rank plastic coals and supports the view that the substances contained in the bitumen fraction of these coals are involved in the development of the plastic state.