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Biomedical subjects

A L Frank

Publications and source records attributed to A L Frank.

At least 73 records · Page 4Linked to original sources

Long-term evaluation of surgically placed amalgam fillings.

The coauthors of this article had developed the clinical impression that whereas surgically placed amalgam fillings are successful on a short-term basis, the long-term prognosis for these cases may not be nearly as favorable. In order to test this hypothesis, as many patients as could be contacted, either directly or indirectly, who had been treated before 1981 were evaluated. Excluded from this study were cases for which failure could be attributed to any reason other than failure from the amalgam reverse filling. Therefore, all cases included had to demonstrate periapical healing prior to ultimate breakdown. On this basis, 60 of 104 teeth (57.7%) were considered to be successful and 44 teeth (42.3%) were determined to be failures.

Dental Amalgam↗

Differential neutron energy spectra measured on spacecraft in low Earth orbit.

Two methods for measuring neutrons in the range from thermal energies to dozens of MeV were used. In the first method, alpha-particles emitted from the 6Li(n,alpha)T reaction are detected with the help of plastic nuclear track detectors, yielding results on thermal and resonance neutrons. Also, fission foils are used to detect fast neutrons. In the second method, fast neutrons are recorded by nuclear photographic emulsions (NPE). The results of measurements on board various satellites are presented. The neutron flux density does not appear to correlate clearly with orbital parameters. Up to 50% of neutrons are due to albedo neutrons from the atmosphere while the fluxes inside the satellites are 15-20% higher than those on the outside. Estimates show that the neutron contribution to the total equivalent radiation dose reaches 20-30%.

Cosmic Radiation↗

Linear energy transfer (LET) spectra of cosmic radiation in low Earth orbit.

Integral linear energy transfer (LET) spectra of cosmic radiation (CR) particles were measured on five Cosmos series spacecraft in low Earth orbit (LEO). Particular emphasis is placed on results of the Cosmos 1887 biosatellite which carried a set of joint U.S.S.R.-U.S.A. radiation experiments involving passive detectors that included thermoluminescent detectors (TLDs), plastic nuclear track detectors (PNTDs), fission foils, nuclear photo-emulsions, etc. which were located both inside and outside the spacecraft. Measured LET spectra are compared with those theoretically calculated. Results show that there is some dependence of LET spectra on orbital parameters. The results are used to estimate the CR quality factor (QF) for the Cosmos 1887 mission.

Cosmic Radiation↗

Depth distribution of absorbed dose on the external surface of Cosmos 1887 biosatellite.

Significant absorbed dose levels exceeding 1.0 Gy day-1 have been measured on the external surface of the Cosmos 1887 biosatellite as functions of depth in stacks of thin thermoluminescent detectors (TLDs) of U.S.S.R. and U.S.A. manufacture. The dose was found to decrease rapidly with increasing absorber thickness, thereby indicating the presence of intensive fluxes of low-energy particles. Comparison between the U.S.S.R. and U.S.A. results and calculations based on the Vette Model environment are in satisfactory agreement. The major contribution to the dose under thin shielding thickness is shown to be from electrons. The fraction of the dose due to protons and heavier charged particles increases with shielding thickness.

Cosmic Radiation↗

Inflammatory resorption caused by an adjacent necrotic tooth.

A case history is presented with a large periapical lesion and a perforating resorption defect on a cuspid. Endodontic therapy was performed, presuming that the necrotic cuspid caused the inflammatory response. No radiographic healing was evident 18 months after endodontic therapy. Considerable healing was demonstrated 6 months later, following the extraction of an adjacent tooth with prior root canal therapy. It was concluded that the failing root canal therapy of the extracted tooth was the primary factor leading to the inflammatory lesion, the resorptive perforation of the adjacent tooth, and its pulpal necrosis. It has not been reported prior that inflammatory resorption can result from the pulpal necrosis of an adjacent tooth.

Adult↗

Human monoclonal antibodies to influenza virus: IgG subclass and light chain distribution.

Three adults and three children were immunized with inactivated or live attenuated influenza vaccines and 98 IgG monoclonal antibodies derived from EBV immortalization of their blood lymphocytes were studied. All antibodies reacted specifically with influenza A H3N2 or H1N1 whole virus and 73 of 74 tested reacted with the purified HA glycoproteins. The majority (76%) of 77 monoclonal antibodies adequately tested by ELISA or solid phase RIA contained lambda light chains. ELISA analysis of the IgG subclass of the six persons' postimmunization anti-influenza serum activity and of monoclonal antibodies derived from them showed a similar predominance of IgG1.

Adult↗

Gas taxes and motor vehicle fatalities.

Economists view taxes as a more efficient means of reducing the consumption of a product than regulation. They have therefore suggested raising cigarette and alcohol taxes to reduce the undesirable effects of tobacco and alcohol on the public's health. This essay suggests that a gasoline tax can have similar beneficial influences on reducing highway deaths and injuries. Moreover, if some proceeds of the tax are used to finance mass transit, the regressivity of the tax can be ameliorated.

Accidents, Traffic↗

Haemophilus influenzae type b immunization of children with sickle cell diseases.

Haemophilus influenzae type B vaccine is recommended for children 1.5 to 6 years of age with sickle cell anemia, but the adequacy of their response is unknown. A total of 69 children with sickle cell syndromes, 1.5 to 5.6 years of age, were immunized with two vaccines alternatively, single blind. PRP vaccine was given to 36 children and a diphtheria toxoid conjugated vaccine, PRP-D, was given to 36. Coded pre- and postvaccine sera were tested by radioimmunoassay for anti-PRP antibody. The groups did not differ in age distribution or type of sickle hemoglobinopathy. Preexisting antibody levels were low in both vaccine groups; 65% were less than 0.15 microgram/mL. The vaccines were safe but associated with frequent minor reactions. PRP-D gave higher geometric mean titers and mean fold titer increase than PRP in all children (15.58 micrograms/mL [234-fold] v 2.63 micrograms/mL [29-fold]) and in the subgroups 1.5 to 2.5 years of age or with pretiter values less than 0.15 microgram/mL. Titers for 64% of children receiving PRP and 94% receiving PRP-D were greater than or equal to 1.0 microgram/mL. Thus, both vaccines were useful in this population, but PRP-D was more immunogenic. Duration of antibody levels postvaccination, booster responses, and PRP-D immunogenicity in younger children with sickle cell syndromes all require further study.

Antibody Formation↗