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Biomedical subjects

R E Olson

Publications and source records attributed to R E Olson.

At least 73 records · Page 4Linked to original sources
PubMed1988

Differences in psychological need hierarchies between black and white drug addicts.

A total of 109 Black and White heroin and cocaine addicts in treatment for drug abuse were compared on the Adjective Checklist (ACL). We found that the White addict had a significantly different pattern of needs than did the Black addict, characterized by more psychological dependence, distress, and maladjustment. Consistent with the MMPI literature in this area, the ACL provides an accurate evaluation of personality dimensions among drug addicts, and White addicts are more psychologically maladjusted than Black addicts.

Adult↗
PubMed1988

Amino acid-restricted diets in the treatment of mammary adenocarcinoma in mice.

The effect of a diet moderately restricted in tryptophan on the tumor and the nutritional status of C3H mice bearing mammary adenocarcinoma was examined. Five groups of female tumor-bearing mice were fed ad libitum a diet containing 1) 15% casein, 2) 15% amino acid mixture, 3) 15% amino acid mixture restricted in tryptophan 4) 15% zein supplemented with lysine and tryptophan or 5) 15% zein supplemented with lysine and restricted in tryptophan. Another group of tumor-free mice of similar age fed 15% casein served as a control for the tumor-bearing group fed the 15% casein diet. Moderate restriction of tryptophan in the diet appeared to have no effect on the tumor status of the animal. Tumor burden usually induced malnutrition in the animal. However, tryptophan restriction did not further aggravate this malnutrition. The source of protein, whether casein, amino acid mixture or zein, appeared to make a difference in nutritional status of tumor-bearing animals though not in tumor status. Casein-fed animals generally tended to have higher values for all the nutritional markers studied than did animals fed the amino acid mixture or zein.

Adenocarcinoma↗
PubMed1988

Differences in psychological need hierarchy between program completers and dropouts from a drug abuse treatment program.

Psychological need patterns among 116 drug addicts in treatment were measured with the Adjective Checklist. Compared to program completers, program dropouts had higher needs for autonomy and aggression and lower needs for deference, nurturance, and affiliation. This personality style may form the basis of dropping out, among certain types of addicts in certain types of programs, when faced with situational, environmental, or interactional stress. Results also suggest that we may be able to identify a personality pattern at risk for premature termination before the person experiences the impulse to leave.

Adult↗
PubMed1988

Differences in psychological needs among drug abusers: first admissions compared to recidivists.

A group of 58 recidivists were compared with a group of 58 first-admission patients in drug abuse treatment, using the Adjective Checklist measuring basic psychological needs. Compared to the recidivists, the first-admission patients scored significantly higher in the needs for Exhibition, Autonomy, Aggression, and Change. A Personality composite for this need configuration was described, and the clinical implications of these results emphasized the need to give attention to the special needs of the patient who is in drug abuse treatment for the first time.

Adult↗
PubMed1986

Treatment of mitochondrial myopathy due to complex III deficiency with vitamins K3 and C: A 31P-NMR follow-up study.

A patient with mitochondrial myopathy due to complex III deficiency who was treated with vitamin K3 (menadiol sodium diphosphate, 40 mg daily) and vitamin C showed clinical improvement. A 1-year study with phosphorus 31 nuclear magnetic resonance (31P-NMR) monitoring has shown that clinical and metabolic improvement was maintained by this therapy; increasing the dose of vitamin K3 to 80 mg daily improved the bioenergetic state of the patient's muscles at rest; postexercise recovery was less responsive to the increased dose; and a higher dose of vitamin K3 (80 mg/day) did not produce side effects. The differential therapeutic effects of vitamin K3 at rest and during exercise recovery are probably due to the differential kinetics of each metabolic state. Monitoring muscle bioenergetics with 31P-NMR is valuable in documenting therapeutic improvements in mitochondrial myopathies.

Adult↗
PubMed1986

Wendell H. Griffith (1895-1968). Biographical sketch.

Wendell Griffith made an indelible impression on his students, his colleagues and the broad field of the nutrition sciences. He was the prototype of the physiological chemist studying intricate problems of intermediary metabolism in the whole animal or human body. His early scientific reports on choline and amino acid metabolism set a high standard for intellectual precision and literary clarity. Dr. Griffith's last research paper was entitled "The Present Knowledge of Methyl Groups in Nutrition" and appeared in Nutrition Reviews in 1968. In this paper he reviews the substance of figure 2, which depicts the advancement in knowledge of choline metabolism, methyl biosynthesis, and transmethylation during his career. It is fortunate that Dr. Griffith was able to witness many of the developments in a field that he had pioneered. If he were alive today, he would be delighted to see how much further this field has moved. Wendell Griffith was a complete man. He combined the traits of high intelligence with a selfless patience and kindness, uncommon in productive scientists. His lucid and absorbing lectures were a joy to his students. Furthermore, he was a mentor with warmth and charm in his relationships to his graduate students and young faculty members and was a superb role model for them. After they left his department he was most supportive. Part of his own rejuvenation, I am sure, occurred in the out-of-doors where he loved to garden, hike and fish. Griff did not grow old, or it seemed he did not. He died at the age of 72 in Baltimore from a brain tumor that was of relatively sudden onset, and is buried in Oak Hill cemetery in Kirkwood, MO, a suburb of St. Louis. He enriched the lives of all of us who had the good fortune to know him. Moreover, his work lives on to stimulate the minds of all serious students of biochemistry and nutrition.

History, 20th Century↗
PubMed1986

Effects of a concurrent clinical education assignment on student concerns.

Students participating in a concurrent pattern of clinical education spend part of the day or week in didactic instruction and the remaining portion in clinical education. The purpose of this descriptive study was to identify concerns expressed by students before and after an early concurrent assignment and before a nonconcurrent assignment. Twenty junior level baccalaureate degree students participated in open-ended taped interviews before and after a concurrent assignment that occurred during the first six months of their professional program. The most frequently expressed concerns were about interpersonal interactions, the students' knowledge, and treatment procedures. The students expressed more concerns before the concurrent assignment than after the concurrent assignment and before a nonconcurrent assignment. We conclude that the concurrent assignment builds students' confidence in their affective and psychomotor skills.

Adult↗
PubMed1986

Preaffiliation and postaffiliation concerns expressed by physical therapy students.

The purpose of this descriptive study was to identify clinical education concerns expressed by physical therapy students at a midwestern university. Twenty senior-level baccalaureate degree students participated in open-ended taped interviews conducted after the first five-week affiliation and before and after the next three five-week affiliations that were integrated into their programs of study. The most frequently expressed concerns regarded clinical techniques and interpersonal relationships. Concerns about clinical techniques were expressed most frequently before an affiliation. Concerns about personal interactions were expressed most frequently after an affiliation. Many of those students who expressed concerns about interpersonal relationships expressed the same concerns after consecutive affiliations. A difference existed between concerns expressed after an acute care affiliation and concerns expressed after a rehabilitation affiliation. Through the identification of student-expressed preaffiliation and postaffiliation concerns, student-educator interactions may be improved.

Adult↗
PubMed1984

Localization of the menaquinone-0 alkylating enzyme in the smooth reticulum of chicken liver microsomes.

The alkylation of menaquinone-0 to menaquinones occurs in the microsomal fraction of chick and rat liver. Subfractionation of chick microsomes into smooth and rough reticulum was achieved by density gradient centrifugation. The alkylation enzyme was localized in the smooth reticulum with an activity of 155 pmol/mg per h, about 50-fold greater than that in the rough reticulum. The membrane-bound alkylating enzyme system requires reduced menaquinone-0 and is phospholipid-dependent.

Alkyl and Aryl Transferases↗
PubMed1984

Kinetics of carboxylation of endogenous and exogenous substrates by the vitamin K-dependent carboxylase.

The vitamin K-dependent carboxylation of the exogenous pentapeptide, Phe-Leu-Glu-Glu-Ile, and endogenous liver microsomal protein was studied in solubilized rat liver microsomes. The MnCl2 stimulation of the vitamin K-dependent pentapeptide carboxylation rate, which is conducted at subsaturating concentrations of pentapeptide, is due to the cation's ability to lower the Km of the substrate. Although there are clear kinetic differences observed between the carboxylation rates for the pentapeptide and the endogenous protein substrates, several lines of evidence suggest that the same carboxylase system is responsible for both. These points of evidence are (i) the initial velocity of endogenous protein carboxylation is lowered in the presence of 3 mM pentapeptide; (ii) the presence of endogenous microsomal protein substrate causes an initial lag in pentapeptide carboxylation; and (iii) this initial lag phase is not observed when the total endogenous substrate pool is carboxylated by a preincubation reaction prior to the addition of pentapeptide.

Animals↗
PubMed1984

Covalent modification of the solubilized rat liver vitamin K-dependent carboxylase with pyridoxal-5'-phosphate.

The carboxylation of the pentapeptide substrate, Phe-Leu-Glu-Glu-Ile, by a rat microsomal vitamin K-dependent carboxylase was stimulated two- to threefold at pyridoxal-5'-P concentrations between 0.5 and 1.0 mM. This stimulation was reduced at concentrations higher than 1.0 mM. The Km for the pentapeptide was lowered twofold in the presence of 1 mM pyridoxal-5'-P. The activation by pyridoxal-5'-P is specific, as 1 mM pyridoxal, pyridoxine, pyridoxine-5'-P, pyridoxamine, pyridoxamine-5'-P, or 4-pyridoxic acid did not stimulate the pentapeptide carboxylation rate. All six analogs, as well as formaldehyde and acetaldehyde, inhibited the carboxylation reaction in a concentration-dependent manner. The activation of the carboxylase by pyridoxal-5'-P appeared to be mediated by its direct binding to the enzyme via Schiff base formation. Sodium borohydride reduction of solubilized microsomes in the presence of pyridoxal-5'-P, followed by dialysis to remove unbound material, resulted in a carboxylase preparation with a specific activity twice that of the untreated control microsomes. The derivatized enzyme was not further stimulated by added pyridoxal-5'-P. This derivatized carboxylase could be obtained in the absence of pentapeptide and divalent cations. The stimulation of the carboxylase activity by divalent cations and pyridoxal-5'-P was mediated at separate site(s) on the enzyme. Studies of the NH2-terminal pyridoxalated pentapeptide with both a normal and PLP-modified enzyme, in the presence and absence of PLP, demonstrated competition of the pentapeptide PLP moiety to a PLP site on the enzyme. It was concluded that pyridoxal-5'-P forms a covalent attachment to an epsilon-NH2 of a lysine near the active site of the carboxylase.

Animals↗
PubMed1984

The function and metabolism of vitamin K.

Since the discovery of gamma-carboxyglutamic acid a decade ago, great progress has been made in advancing our knowledge of the function and metabolism of vitamin K. The distribution of this new amino acid in proteins of diverse origin and the presence of the vitamin K-dependent carboxylase in diverse tissues have emphasized the widespread significance in biology of a new triad: vitamin K, Gla, and calcium. New knowledge has been obtained on the importance of the utilization and reutilization of vitamin K, whose body pools are extremely low for a fat-soluble vitamin, for the posttranslational carboxylation of peptide-bound glutamate residues in the vitamin K-dependent proteins. The regulation of the activation of the vitamin K-vitamin K-epoxide cycle by drugs and nutrients appears to be the key to controlling the synthesis of vitamin K-dependent proteins, eight of which are involved in blood coagulation. The purification of the vitamin K-dependent gamma-glutamyl carboxylase has turned out to be a more formidable task than anyone had imagined. Many of the questions about its complicated mechanism, utilizing as it does four substrates (KH2, O2, CO2, and a Glu-containing peptide), cannot be answered until the enzyme is homogeneous. Basically, the vitamin K-dependent carboxylase system consists of a specialized microsomal electron transport system coupled to a carbon dioxide fixation. The reaction does not require ATP but apparently utilizes the energy of vitamin KH2 oxidation to perform the chemical work required in Gla synthesis. Why a quinone is employed in this system when other mechanisms exist for CO2 fixation is still mysterious unless the whole process goes by one electron transport. Whether the final CO2 addition to the gamma-methylene group of glutamic acid is a radical reaction is unsettled. Since this enzyme is an intrinsic membrane-bound protein, the scientific attack on its structure and function is at one of the present frontiers of molecular biology. A view of the synthesis of vitamin K-dependent proteins in the RER is shown in Figure 9. Finally, the nutritional requirements for vitamin K in humans are unknown. An unknown fraction of vitamin K in humans is derived from menaquinone biosynthesis in the intestinal flora. Contributions from diet and biosynthesis have not yet been quantitated. Sensitive HPLC methods for measuring plasma phylloquinone are now available, and related methods for measuring long-chain menaquinones can be developed.

4-Hydroxycoumarins↗