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Biomedical subjects

M Ellis

Publications and source records attributed to M Ellis.

At least 217 records · Page 12Linked to original sources
PubMed1982

Synthesis of cytoskeletal and membrane polypeptides by the organ cultured chicken lens.

The synthesis of cytoskeletal and membrane polypeptides of the chick lens epithelium, superficial cortical fiber cells and deep cortical fiber cells was studied in the organ-cultured lens. The synthetic activity of the cytoskeletal polypeptides was restricted to the epithelium and superficial cortical fiber cells while membrane polypeptides were synthesized by deep cortical fiber cells as well. None of the polypeptides was observed to be synthesized by the lens nuclear fiber cells.

Animals↗
PubMed1981

The relationship between the Rutter A Questionnaire and an interview with mother assessing child psychiatric disturbance among enuretic children.

Forty-one children who were being treated in a paediatric clinic for enuresis were studied to see how many of them were psychiatrically disturbed on clinical assessment and to ascertain the usefulness of 2 cut-off points of T (total) scores on the Rutter A scale in identifying them. A score of 13 or more which had previously been recommended was found to be inadequate in this group of cases. There were indications that a cut-off point of 18 or more was more appropriate. The importance of knowing the base rate of psychiatric disorder in the population on which the questionnaire is being used is emphasized, since this affects the selection of an appropriate cut-off point.

Adolescent↗
PubMed1980

Evaluation of heroin maintenance in controlled trial.

Ninety-six confirmed heroin addicts requesting a heroin maintenance prescription were randomly allocated to treatment with injectable heroin or oral methadone. Progress was monitored throughout the next 12 months by research workers operating independently of the clinic. Heroin can be seen as maintaining the status quo, with the majority continuing to inject heroin regularly and to supplement their maintenance prescription from other sources; it was associated with a continuing intermediate level of involvement with the drug subculture and criminal activity. Refusal to prescribe heroin while offering oral methadone constituted a more confrontational response and resulted in a higher abstinence rate, but also a greater dependence on illegal sources of drugs for these who continued to inject. Those offered oral methadone tended to polarize toward high or low categories of illegal drug use and involvement with the drug subculture, and were more likely to be arrested during the 12-month follow-up. There was no difference between the two groups in terms of employment, health, or consumption of nonopiate drugs. Refusal to prescribe heroin resulted in a significantly greater drop out from regular treatment.

Adolescent↗
PubMed1980

The argon laser in otology.

The use of lasers in microsurgery is now an accepted procedure. As we learn more about the absorption properties of biologic tissue, we can use different electromagnetic wave lengths to accomplish surgical alteration of these tissues. The electromagnetic wave length of the Argon laser is compatible for surgical alteration of the soft tissue and bone of the middle and inner ear. Thirty patients requiring external ear canal or middle ear surgery were treated using the Argon laser during the course of the surgical procedure. The treatment of soft tissue pathology included tympanoplasty with fascia graft, control of bleeding, lysis of adhesions, and myringotomies performed using the Argon laser. Osseous disease of the external canal was removed and stapedectomy was performed, using the Argon laser on 15 patients. A review of the physics of laser energy and its application in otology is presented. The results of this investigative study demonstrate the advantages of the Argon laser in otologic microsurgery.

Argon↗
PubMed1979

Nuclease digestion studies of mouse chromatin as a function of age.

Chromatin is organized into a repeating structure (nucleosome) made up of proteins and DNA. Micrococcal nuclease and DNAase I have been used to probe this structure in nuclear populations from three tissues (liver, brain and heart) of the inbred mouse strain C57BL at different ages. For those parameters examined in each tissue, chromatin contained essentially the same features of nucleosomal organization, regardless of the age of the mouse. Thus, the rate and extent of nuclease digestion, the size of the DNA repeat unit and nucleosome core are not significantly different as a function of age. However, the accessibility of internucleosomal DNA to micrococcal nuclease, as determined by measuring the DNA size distribution after nuclease cutting, may be partially limited in brain chromatin (but not liver or heart) of older animals. These results indicate that there are no gross, age-related changes in the conformational state or organization of chromatin in these tissues. The results do not exclude smaller alterations in chromatin which might occur with age and which the methodology employed might not be sensitive enough to detect.

Aging↗
PubMed1979

The structural organization of mouse chromatin as a function of age.

Chromatin is organized into a repeating structure (nucleosome) made up of proteins and DNA. Micrococcal nuclease and DNAase I have been used to probe this structure in nuclear populations from three tissues (liver, brain, and heart) of the inbred mouse strain C57BL at different ages. For those parameters examined, for each tissue, chromatin contained essentially the same features of nucleosomal organization, regardless of the age of the mouse. Thus, the rate and extent of nuclease digestion and the size of the DNA repeat unit and nucleosome core are not significantly different as a function of age. However, the accessibility of internucleosomal DNA to micrococcal nuclease, as determined by measuring the DNA size distribution after nuclease cutting, may be partially limited in chromatin of brain (but not liver or heart) of older animals. These results indicate that there are no gross, age-related changes in the conformational state or organization of chromatin in these tissues. The results do not exclude smaller alterations in chromatin that might occur with age, which the current methodology might not be sensitive enough to detect.

Aging↗
PubMed1978

Analgesics. 1. Synthesis and analgesic properties of N-sec-alkyl- and N-tert-alkylnormorphines.

A series of N-sec- and N-tert-alkylnormorphines was synthesized and evaluated for analgesic potency, antagonist activity, and opiate receptor binding. Computer-assisted conformational analysis profiles were utilized to assist in the selection of compounds for synthesis and correlation of receptor events with in vivo observations. N-tert-Alkylnormorphines 5a-c were devoid of agonist activity; however, some sec-alkyl analogues showed interesting mixed agonist-antagnoist actions. N-sec-Butyl- and N-(alpha-methylally)normorphine were separated into R and S isomers, which exhibited quantitative pharmacological differences. The N-sec-butyl S isomer 10a showed analgesia approximating morphine with nalorphine-like antagonist activity. Preliminary testing indicates only slight evidence for physical dependence with this compound.

Analgesics↗
PubMed1977

Fatal accidents to children: implications for prevention.

Effects to prevent childhood accidents should be directed at the causes of serious injury and death, rather than at the causes of the vast number of emergency department trivial injuries. This paper analyses fatal accidents, and suggests areas in which efforts at prevention may be effective. It emphasizes the importance of motor car accidents, and drowning accidents in childhood.

Accident Prevention↗
PubMed1977

Application of 13C-NMR spectroscopy to in vitro analysis of enzyme kinetics.

The conversion of D,L-alpha-13C-histidine to similarly labeled alpha-13C histamine by bacterial and mammalian histidine decarboxylase was studied by 13C-NMR spectroscopy and GLC-mass spectrometry. The results obtained with the partially purified bacterial enzyme were in essentially perfect agreement with results obtained simultaneously with a standard radioisotopic method using carboxyl-labeled-14C-L-histidine. For a crude tissue preparation of the mammalian enzyme, the radioisotopic method indicated an activity three times that based on 13C-NMR measurement of alpha-13C-histamine. The difference in results was accountable in terms of additional 13C-NMR signals attributable to products other than histamine due in part to enzymatic degradation of the latter.

Animals↗
PubMed1977

Potential histidine decarboxylase inhibitors. 1. alpha- and beta-substituted histidine analogues.

Histidine analogues with alkyl substitution at Calpha and Cbeta were prepared as potential inhibitors of specific histidine decarboxylase. Activity was assessed in vitro using extracts of rat pyloric stomach and a radioisotopic assay of 14CO2 evolved from carboxyl-14C-labeled histidine. alpha-Substituted analogues (C2-C4) including 2-hydroxyethyl were less potent than alpha-methylhistidine; the alpha-n-butyl analogue was completely inactive at 10(-3) M. Similarly, beta,beta-dimethylhistidine and homohistidine failed to exhibit activity at 10(-3) M.

Animals↗
PubMed1977

The effect of feeding magnesium-enriched diets on the quality of the albumen of stored eggs.

1. Pullets were given from 1-d-old diets containing 1-6, 4-1, 8-1 and 12-0 g Mg/kg. Only small effects of these diets on live weight, food consumption, egg number, egg weights or egg-shell thickness were observed except at the highest level (12-0 Mg/kg) which caused diarrhoea and an appreciable lowering of the live weight of growing pullets. A further group was given from point-of-lay a diet containing 9-3 g Mg/kg. 2. Eggs laid on 3 consecutive days from each of eighteen hens were collected at intervals of 3 weeks until the birds were 68-5 weeks old. Eggs laid on the 3rd day were used to determine the initial proportion of thick egg-white present and also the concentration of Mg, Ca, Na and K in the thick egg-white. Eggs laid on the 1st and 2nd days were stored at 20 degrees for 20 d to establish the proportion of thick egg-white remaining after storage. 3. With the unsupplemented diet the proportion of residual thick egg-white after storage of eggs for 20 d at 20 degrees was 306, 161 and 305 mg/g total egg-white when the hens were 26-5, 53-5 and 68-5 weeks of age respectively. When the diet containing 9-3 g Mg/kg was given, the proportion of thick egg-white after storage remained approximately 400 mg/g throughout the period of the trial. 4. The mean Mg concentration in the thick egg-white of eggs laid by hens given unsupplemented diets was 5-77 mM. The addition of extra Mg to the diet increased the content of Mg in the thick egg-white, for example when the diet contained 9-3 g Mg/kg the mean concentration rose to 7-69 mM.

Animal Feed↗