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Biomedical subjects

R Falk

Publications and source records attributed to R Falk.

At least 91 records · Page 5Linked to original sources
PubMed1976

Interpretive accuracy of abbreviated MMPIs.

The interpretive accuracy of the standard MMPI and three abbreviated forms was assessed and compared with a sample of psychiatric inpatients. Psychiatric teams evaluated the accuracy of the interpretation of one abbreviated form and the standard form for their patients. Only the MMPI-168 obtained comparable ratings to the standard form.

Adolescent↗
PubMed1975

Partial losses of sex chromosomes induced by X-rays in spermatozoa of Drosophila melanogaster.

The frequency of induced partial and complete losses of sex chromosomes from spermatozoa of Drosophila melanogaster was determined by mating irradiated males to females heterozygous for an attached-X Y chromosome and for a bb-deficient chromosome. The relative involvement of the X- and Y-chromosomes in partial losses was determined by (a) irradiating males with an X-chromosome centromere marked by a y+ translocated to the short right arm, and a Y-chromosome marked by w+, and (b) comparing the frequencies of fragments recovered from irradiated males with a normal, marked Y-chromosome and from irradiated males and a deleted bb Y-chromsome. 50-80% of the induced losses of sex-chromosomes in rod-X/Y males were partial losses, whereas only 25% of those induced in ring-X/Y males were partial losses. More than 70% of the recovered fragments were of Y-chromosome origin. Fragments recovered from attached-X-Y sons of irradiated males wer checked for the presence of the most proximal euchromatic X-chromosome genes. Most fragments of the rod-X were broken more proximally than bb. In the ring-X there was an excess of fragments broken in the proximal euchromatin. It was concluded that many fragments of the Y-chromosome was due to breaks induced by one-hit events, in both arms of the chromosome that were folded upon themselves. A similar mechanism had been postulated earlier for fragments of the ring-X chromosome.

Animals↗
PubMed1975

Temperature-sensitive prune (pn) mutations of Drosophila melanogaster.

Temperature-sensitive mutations, at the prune locus (pnts) of Drosophilia melanogaster, were induced with EMS. The majority of the new class of mutations, designated pnts-e, do not interact with the mutation Killer of prune (Kpn) at all of the experimental temperatures, i.e., pnts-e, Kpn flies do not die. One mutation, designated pnts-ek, is temperature-senstive with respect to both the eye coloration and the interaction with Kpn. pntr (temperature-non-sensitive), pnts-e, and pnts-ek alleles were found to differ with respect to both quantity of drosopterines and the color of the eyes. The temperature-sensitive period (TSP) for pn eye color occurs at a late pupal stage. The TSP for the pn--Kpn interaction lasts from the beginning of the first laraval instar to eclosion [22]. It is concluded that all pn mutations known to date occupy the same functional unit. The various pn mutations affect the same metabolic step to various degrees: the eye color phenotype results from a reduction in the end product, while the interaction with Kpn depends on the amount of the accumulated precursor. No recombination between pn alleles was found among more than 106 zygotes that were scored. The reasons for this failure are discussed.

Alleles↗
PubMed1975

The allotransplantation of partial joints in the treatment of osteoarthritis of the knee.

Nine allografts replacing part of the knee have been carried out in 8 patients. In all patients the graft was incorporated without clinical evidence of rejection. In one case a low grade infection was brought under control without surgery and thus far has not impaired the results. All patients have a good functional range of movement and the alignment of the knee has been maintained by the grafts which display little or no collapse at all. Histological evidence in one case revealed cartilage viability at 14 months. Two years interim observations are encouraging enough to continue on with this technique in the knee with disease severe enough not to be helped by osteotomy but not so diffusely damaged as to require total knee arthroplasty.

Aged↗
PubMed1975

Radiation dose to the human body from intravenously administered 75Se-sodium selenite.

The dose of radiation to the human body and some of its organs after intravenous administration of 75Se-sodium selenite for diagnostic purposes has been calculated on the basis of followup of 26 patients for as long as 517 days with measurements of: 1. The retention of 75Se in the whole body. 2. The retention of 75Se in the blood, liver, kidneys, ovaries, testicles, and hair. 3. The excretion of 75Se in urine and feces. Whole-body counting and profile scanning were done on the patients and samples of blood from different organs, urine, and feces were measured for radioactivity. The dose of radiation received was calculated for an average patient of 70 kg. These doses were found to be slightly higher than previously reported on a smaller number of patients and with a shorter follow-up. They were slightly lower than those from 75Se-methionine to the whole body but higher to the liver and kidneys. The margin of error in this investigation was estimated to be about 20% for the whole-body dose and probably higher for different organs, mostly due to the poorly known rate of retention of selenite in different organs.

Adult↗