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Biomedical subjects

G F Reed

Publications and source records attributed to G F Reed.

At least 55 records · Page 3Linked to original sources
PubMed1987

Effect of heparin on membrane associated clathrin basketwork of cultured cells derived from the stromal-vascular fraction of mouse brown adipose tissue.

The effect of heparin treatment on clathrin basketwork of cell membranes was examined in cultured cells derived from the stromal-vascular fraction of neonatal mouse brown adipose tissue. The cytoplasmic surface of the plasma membrane of ruptured cells was examined with surface replicas. Heparin treatment significantly decreased the extent of clathrin basketwork associated with the membrane from 3.4 to 0.2%. The loss of clathrin basketwork suggests that heparin treatment of these cells affected intracellular sorting processes associated with endocytosis.

Adipose Tissue, Brown↗
PubMed1987

Prevalence, natural history and surgical treatment of exophthalmos.

The 95% confidence limits of exophthalmometer measurements have been defined by a single observer in 105 individuals who had no known thyroid disease, and found to be 10.5-18.8 mm. Measurements in 308 patients with thyrotoxicosis have shown that exophthalmos (greater than 19 mm) of one or both eyes was present in 21.3% of the patients. Among the 122 thyrotoxic patients whose exophthalmometer measurements could be performed annually for 3-19 years after correction of the thyrotoxicosis (usually with 131I), exophthalmos remained stable in 78.7%, worsened in 15.6% and became less severe in 5.7% of the patients. Transantral decompression of the orbits was performed in 15 patients with rapid subjective improvement in all and reduction in exophthalmometer measurements of 3.6 +/- 0.5 (mean +/- SEM) mm, and no serious side-effects. In view of these findings, transantral decompression should be considered more frequently in the treatment of severe or cosmetically damaging exophthalmos.

Adolescent↗
PubMed1987

Protection against the lethal effects of pentobarbital in mice by a benzodiazepine receptor inverse agonist, 6,7-dimethoxy-4-ethyl-3-carbomethoxy-beta-carboline.

The benzodiazepine receptor inverse agonist 6,7-dimethoxy-4-ethyl-3-carbomethoxy-beta-carboline (DMCM) (1.5-15 mg/kg) was administered to mice 5 min after a lethal (LD94) injection of pentobarbital. DMCM (1.5-5 mg/kg) increased short-term (1 h) survival in a dose-dependent fashion, with an optimum survival rate more than five times greater than mice receiving pentobarbital alone. Statistically significant increases in long-term (24 h) survival were also observed after both 5 and 10 mg/kg of DMCM (34 and 33%, respectively) compared with animals receiving pentobarbital alone (6%). Two doses of DMCM (5 and 2.5 mg/kg, respectively) administered 55 min apart produced an even greater increase (58%) in 24-h survival rates. Doses of DMCM that increased 1- and 24-h survival were not lethal when administered alone, and were below the dose that produced convulsions in 50% (CD50) of the animals. The protective effects of DMCM were blocked by pretreatment with the benzodiazepine receptor agonist ethyl-8-fluoro-5,6-dihydro-5-methyl-6-oxo- 4H-imidazo[1,5a][1,4]benzodiazodiazepine-3-carboxylate (Ro 15-1788), which suggests the effects of DMCM are mediated through the benzodiazepine receptor. These findings suggest that DMCM or another benzodiazepine receptor ligand with full inverse agonist qualities could prove effective as an antidote for barbiturate intoxication in man.

Animals↗
PubMed1985

Benzodiazepine-receptor mediated inhibition of isolation-induced aggression in mice.

The effects of a benzodiazepine receptor agonist (diazepam), antagonist (Ro 15-1788), and an "active" antagonist [inverse agonist] (3-carboethoxy-beta-carboline) were examined in an isolation-induced model of aggression. Diazepam (4 mg/kg) and 3-carboethoxy-beta-carboline (10 mg/kg), but not Ro 15-1788, significantly inhibited aggressive behavior in this model. Ro 15-1788 (10 mg/kg) reduced the anti-aggressive actions of both diazepam and 3-carboethoxy-beta-carboline, while mice treated with a combination of diazepam and 3-carboethoxy-beta-carboline had aggression scores increased to values not significantly different from vehicle treated mice. These findings suggest that both diazepam and 3-carboethoxy-beta-carboline have anti-aggressive properties in the isolation-induced model of aggression which are mediated through CNS benzodiazepine receptors.

Aggression↗
PubMed1985

Are there adverse effects of periconceptional spermicide use?

Recent studies have suggested that spermicide exposure around conception may cause congenital malformations, reduced birth weight, or spontaneous abortion. This large, prospective study examined the risk for multiple malformation, patterns of malformations, low birth weight, preterm delivery, and spontaneous abortion in infants whose mothers used spermicides only before or after their last menstrual period, compared with a control group using other contraceptive methods. The multiple malformation rates in women using spermicides only before or after their last menstrual period were 3.8 and 4.8 per thousand, respectively. For the control groups, the corresponding rates were 5.4 and 6.4 (not significant). No pattern of malformations was found in spermicide-exposed infants. The risk of preterm delivery, the risk for producing a low-birth-weight (less than 2500 gm) infant, and the risk of spontaneous abortion were no higher in women exposed to spermicides than in women using other methods of contraception. This study finds no evidence that spermicide exposure around the time of conception is dangerous to the fetus.

Abnormalities, Drug-Induced↗
PubMed1984

An evaluation of the parenteral magnesium load test in weanling rats.

The parenteral magnesium (Mg) load test has reliably identified rats fed two extremes of dietary Mg, but tests of intermediate levels have not been found. The present study was designed to learn: 1) whether the parenteral Mg load test reflects a series of different dietary levels of Mg, rather than just the extremes; 2) what relationship exists between Mg retention and Mg in plasma and in bone at the different dietary levels of Mg; and 3) how the different dietary levels of Mg affect weight gain. Weanling rats were fed six levels of dietary Mg ranging from 0 to 150 mg/100 g purified diet. A negative relationship was found between retention of the Mg load and the level of dietary Mg. Mg retention decreased linearly with increases in plasma Mg and bone Mg. Weight gain was an insensitive index of dietary Mg. The parenteral Mg load test appears to be an acceptable means of indirectly assessing Mg stores in weanling rats with normal renal and cardiovascular status and normal water balance.

Animals↗
PubMed1982

Are spermicides teratogenic?

Recent evidence suggests that spermicides could be teratogenic. In this study, pregnant women provided data at their first prenatal visit on spermicide and other contraceptive exposures in each of the preceding 12 months. Data on malformations in their offspring were obtained by abstracting medical records. Among women practicing contraception before the last menstrual period but not after, the malformation rate in the offspring of spermicide users was no higher than in users of other methods. The same was true of women who continued to practice contraception after the last menstrual period. When malformations were examined by organ system and by individual defect, spermicide exposure again was not associated with an increased risk. Comparing spermicides by active ingredient with other methods of contraception revealed no increased risk of malformations for any compound. Controlling for age, time in pregnancy at which exposure data were collected, concentration of spermicides used, and other possible confounding factors did not alter the results. This study finds no association between maternal spermicide exposure before or after the last menstrual period and congenital malformations.

Abnormalities, Drug-Induced↗
PubMed1979

The estimation of dental caries incidence in the presence of diagnostic error.

Diagnostic error in large scale screening programs for dental caries is frequent, as when teeth initially classified as carious are later diagnosed as never having been affected by caries. This paper presents a general formulation of diagnostic error in dental caries screening. The basic parameter of the formulation is the caries incidence rate. The general formulation of this paper permits an explicit comparison, in a common notation, of two specific models of diagnostic error--one due to Carlos and Senning, the other to Lu. Each model gives rise to a consistent estimator of the incidence rate. The distributional properties of these estimators had not previously been examined because of the dependence of teeth in the same mouth with respect to caries experience. Using the present formulation, the sampling scheme may be regarded as a one-stage cluster sample with mouths as clusters. This approach accounts for intracluster dependence thus permitting the derivation of an estimator of the relevant covariance matrix and a confidence interval for the incidence rate.

Dental Caries↗
PubMed1978

Voice change after radiotherapy. Some preliminary results.

A one-third octave spectral analysis was performed on two sentences spoken by 5 patients with laryngeal cancer, 5 with head/neck cancer not involving the vocal cords, and 12 normal subjects. Recordings were made prior to and at weekly intervals during radiotherapy as well as at periodic intervals post-treatment. Patients with laryngeal cancer exhibited lower spectral levels than normal throughout radiotherapy as well as several months post-treatment. By one year after treatment, the spectral levels of these patients were largely in the normal range. Patients with head/neck cancer not involving the vocal cords exhibited greater than normal sound pressure levels throughout most of the spectrum. These levels remained high even at one month post-treatment. Irradiation of normal vocal cord tissue also seems to result in higher spectral levels.

Aged↗
PubMed1978

Recurrence as a mode of determining efficacy in treatment of carcinoma of the larynx.

A study population of 374 patients with cancer of the larynx was evaluated, treated, and followed at yearly intervals up to a maximum of 18 years post-diagnosis. Of these, 348 received definitive therapy to attempt to eradicate their disease and were followed for recurrence and presence of cancer at death. In Stages I, II, and III recurrence of disease appears to be a very good indicator of therapeutic efficacy. Stage I carcinomas of the larynx should be treated with radiation as the proportions of patients with recurrences were the same for both primary surgical or radiation therapy. In Stages II and III, primary surgical therapy significantly lowered the proportion recurring when compared with primary radiation therapy. In Stage IV carcinomas of the larynx, both survival and recurrence accurately reflect therapeutic efficacy since most patients suffer recurrence of their carcinoma and die of the disease.

Age Factors↗
PubMed1977

Obsessional personality disorder and remembering.

Patients suffering from obsessional personality disorder (anankasts) have been described as possessing 'superior memories', because of the detailed precision of their accounts. At the same time, such classical phenomena as doubt, checking and rumination imply faulty recall. This paradox is discussed, and some predictions drawn from a hypothesis regarding the cognitive charactteristics of obsessional disorder. Findings are presented which indicate that, by comparison with matched psychiatric controls, anankasts do not excel in the long-term recall of factual information or meaningful anecdotal material. But they show the following mnemonic features: (a) Superiority of immediate memory span, reflecting high levels of attention. (b) Superior recall of ambiguous anecdotal material, reflecting a tendency to the pointless 'rehearsal' of such material. (c) Weak redintegration in personal reminiscence. It is suggested that anankasts' doubts about their remembering refer not so much to the correctness of what is being recalled as to the quality of the recalling itself.

Compulsive Personality Disorder↗
PubMed1977

Obsessional cognition: performance on two numerical tasks.

It is argued that obsessional indecision reflects a formal cognitive characteristic, and should therefore be detectable in slower performance of insignificant, neutral tasks. The obsessional will not be handicapped in structured tasks requiring concentration and a deductive approach, but he will be slower in less structured tasks requiring a predominantly inductive approach. Results from two neutral (numerical) tasks support the predictions.

Cognition↗
PubMed1977

Use of computerized axial tomography of the head and neck region.

The use of the computerized axial tomography has been well received in the field of otolaryngology. Five cases are presented illustrating the capability of the total body scanner (Delta scanner) to contribute to radiologic diagnosis below the level of the base of the skull. The advantages of non-invasibility and three dimensionality are compared to the disadvantages of added cost, added radiation exposure, comparatively long exposure time and relatively poor detail. Because of the overall usefulness of this diagnostic tool, evolution of rapid scanning devices with greater detail is awaited with interest.

Adult↗