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Biomedical subjects

M E Harris

Publications and source records attributed to M E Harris.

At least 55 records · Page 3Linked to original sources
PubMed1986

Characterization of human platelet basic protein, a precursor form of low-affinity platelet factor 4 and beta-thromboglobulin.

Platelet basic protein (PBP) was purified from the supernatant of thrombin-stimulated, washed human platelets by ion-exchange, affinity, molecular sieve, and high-performance liquid chromatography (HPLC). The NH2-terminal amino acid sequence was determined by automated Edman degradation, revealing 9 unique residues followed by 10 residues of the established low-affinity platelet factor 4/beta-thromboglobulin (LA-PF4/beta TG) sequence. Among the nine were three basic residues, accounting for the high isoelectric point of PBP. Additional evidence for precursor status includes the immunological cross-reactivity of all three species and the ability of plasmin and trypsin to produce from PBP a species resembling beta TG in charge, hydrophobicity, and size. Tryptic peptide maps of PBP and LA-PF4 obtained by reverse-phase HPLC were very similar, and from each protein, a peptide was isolated which showed the amino acid composition predicted for the COOH-terminal tryptic peptide of beta TG. Normal platelets contained predominantly LA-PF4, with PBP ranging from 10% to 30% of total beta TG antigen. This was true even when fresh platelets were lysed with trichloroacetic acid in order to provide the most complete and rapid inhibition of proteolytic activity. beta TG itself was never detected in this situation or in the release supernatant of stimulated platelets, and only rarely in unprotected lysates. In agreement with earlier results, crude preparations of PBP were mitogenic for 3T3 cells, but highly purified preparations of PBP and LA-PF4 were free of this activity.

Amino Acid Sequence↗
PubMed1984

Students' perception of actual, trivial, and inaccurate personality feedback.

Examined the ability of college students at two levels of defensiveness to discriminate among three types of personality feedback: actual personality feedback based on the student's test scores, trivial feedback which is generally true of all students, and inaccurate feedback which was the exact opposite of the student's actual test scores. The students could reliably discriminate the three types of feedback on the dimensions of uniqueness, usefulness, accuracy, and as a source of new information about themselves. The results are discussed in the context of the Barnum literature to the effect that students can offer valid perceptions of personality descriptions of themselves.

Journal Article↗
PubMed1980

Two modified selenite media for the recovery of Yersinia enterocolitica from meats.

Yersinia enterocolitica is one of the few human pathogens that grows at the proper food refrigeration temperatures of 0 to 5 degrees C. Although the isolation of environmental biotypes of Y. enterocolitica from many types of food and water has been reported in the literature, the recovery of the sensitive strains inoculated into foods has been slow and uncertain. Rapid recovery of several clinical strains inoculated into meats was accomplished by using two modified selenite broths without added nutrients. It was critical to restrict the sample size of the blended meat suspension at the 0.2-g/100 ml level, thereby restricting the growth of the total bacterial population in the selenite enrichment media. Otherwise, the slower growing Y. enterocolitica would be overwhelmed by the faster growing normal bacterial flora from the meat. Both the resistant serotype O:3 and the sensitive O:8 clinical isolates of Y. enterocolitica were recovered from the modified selenite enrichment media after 2 and 3 days of incubation at 22 degrees C.

Alkalies↗
PubMed1980

Rapid detection of staphylococcal thermonuclease on casings of naturally contaminated fermented sausages.

Staphylococcal food poisoning associated with fermented sausages has been a recurring problem. By testing for thermonuclease by direct application of sausage casing disks on the surface of thermonuclease assay agar plates, possible Staphylococcus aureus growth in fermented sausages could be detected simply and rapidly. Koupal-Deibel deoxyribonucleic acid agar was somewhat superior to toluidine blue deoxyribonucleic acid agar for thermonuclease assay of fermented sausage casings. The sensitivity of the thermonuclease casing test was comparable to that of the extraction procedure, and the thermonuclease casing test results were in complete agreement with the thermonuclease assay results by the extraction procedure. The thermonuclease casing test offers government and industry laboratories a useful screening tool which could significantly reduce the problem of staphylococcal enterotoxins in fermented sausages.

Fermentation↗
PubMed1979

Another look at personal validation.

Students' ability to validate the results from their own psychological tests was examined in two experiments. In Experiment I, sophomore, senior, and graduate students were presented with their actual and inverted profiles from the California Psychological Inventory (CPI) and the Students were asked to select their actual profiles. The senior and graduate students could reliably select their own profiles while the sophomore students could not. In Experiment 2, sophomore students were presented with their actual and inverted profiles from the CPI and the Differential Aptitudes Test (DAT) and the students were asked to select their actual profiles. The students were able to reliably select their actual profiles for both tests. The students were much more likely to select their own DAT profile than CPI profile, and they were more confident in their selection of the actual DAT profile.

Journal Article↗
PubMed1977

Effects of testosterone and dihydrotestosterone on spermatogenesis, rete testis fluid, and peripheral androgen levels in hypophysectomized rats.

To compare the effects of testosterone (T) and dihydrotestosterone (DHT) on the maintenance and the restoration of spermatogenesis, hypophysectomized (APX) rats were treated daily for 35 days with 0.5 mg of T propionate (TP) or DHT propionate (DHTP) beginning 5 or 33 days after hypophysectomy. In the maintenance experiment, the weights of the testes and the number of early spermatids were significantly lower in DHTP-than in TP-treated animals, while late spermatids were present only in rats treated with TP. In the restoration experiment, TP increased testicular weight and the number of germinal cells, whereas DHTP had very little effect on the testis. In an attempt to explain these findings, we measured androgen levels in the rete testis fluid (RTF) and peripheral plasma of APX rats treated with TP or DHTP. The concentration of T in the RTF of TP-treated rats was nearly 3-fold higher than the level of DHT in the RTF of animals given DHTP. Plasma T levels measured 1/2, 2, 4, and 24 hours after the last of three daily injections of TP were considerably higher than were the corresponding plasma DHT levels in animals given DHTP. In animals treated with free steroids, peripheral androgen levels between 1/2 and 4 hours after the last injection were much higher in rats given T than in those given DHT, but thereafter this difference disappeared. We conclude that the difference in the ability of subcutaneously injected TP and DHTP to maintain and to restore spermatogenesis in APX rats was due to a difference in androgen levels in the testes of these animals.

Animals↗
PubMed1977

Dream content and its relation to self-reported interpersonal behavior.

THE NATURE of the relationship between those psychological processes which influence waking behavior and cognition, and those which influence the content of nocturnal dreams, is a question both interesting and unresolved. Is a person's approach to life similar in both the dream and the waking state? If someone was experiencing conflict in his life, might we expect to find conflictual situations in his dreams? And if, on the contrary, a person's waking expectations and experiences were harmonious, might we expect him to manifest conflict-free dreams? These are the questions to which we addressed ourselves in the present study.

Aggression↗
PubMed1975

Bacteriological survey of raw beef patties produced at establishments under federal inspection.

At the time of manufacture, 76% of 74 sets of raw beef patties collected in 42 federally inspected establishments had aerobic plate counts of 1,000,000 or fewer/g; 84% contained 100 or fewer coliforms/g; 92% contained 100 or fewer Escherichia coli/g; and 85% contained 100 or fewer staphylococcus aureus/g (geometric means of 10 patties/set). Salmonellae were isolated from only three (0.4%) of 735 beef patties.

Aerobiosis↗
PubMed1975

Maintenance of rate testis fluid testosterone and dihydrotestosterone levels by pregnenolone and other C21 steroids in hypophysectomized rats.

This study was undertaken to determine whether maintenance of spermatogenesis in hypophysectomized rats by pregnenolone and other C21 steroids may be due to in vivo conversion of these compounds to androgens. Hypophysectomized rats were treated sc with 2 mg of pregnenolone, 17-hydroxypregnenolone, progesterone, 17-hydroxyprogesterone or testosterone propionate in 0.2 ml sesame oil daily for 14 days beginning 2 days after hypophysectomy. Rete testis fluid (RTF), peripheral blood, and testicular venous blood were collected on the day of the last injection. Testosterone (T) and dihydrotestosterone (DHT) were measured by radioimmunoassay after chromatographic separation. Results demonstrate that T and DHT could be found in the RTF of C21 steroid-treated hypophysectomized rats at levels similar to those seen in the intact rat. Results imply that the maintenance of spermatogenesis by C21 steroids is probably due to the conversion of these compounds to T in the testis. Relatively little T was released from the testis into the peripheral circulation of these rats since T levels in testicular venous plasma were low and peripheral plasma T levels were not distinguishable from those seen in untreated hypophysectomized rats. Histological examination of the testes of C21 steroid-treated hypophysectomized rats showed nearly quantitative maintence of spermatogenesis and atrophy of Leydig cells. These findings suggest that most of the conversion of C21 steroids to androgens occurred in the seminiferous tubules.

17-alpha-Hydroxypregnenolone↗
PubMed1973

Bacteriological survey of frozen meat and gravy produced at establishments under federal inspection.

During visits to 34 federally inspected establishments producing frozen meat and gravy, 541 production line samples and 535 finished product units were collected for bacteriological analyses. It was found that more than 70% of the sets of finished product (10 units/set) produced under good manufacturing practices had: (i) four or fewer coliform-positive units, (ii) two or fewer Escherichia coli-positive units, (iii) three or fewer Staphylococcus aureus-positive units, and (iv) an aerobic plate count of fewer than 50,000/g (geometric mean of 10 units). All finished product units were negative for salmonellae.

Aerobiosis↗