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Biomedical subjects

M G Miller

Publications and source records attributed to M G Miller.

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

Finger clubbing in cystic fibrosis.

Finger clubbing was measured in 73 of 105 patients with cystic fibrosis undergoing full assessment. The sign correlated well with the chest x ray score and indices of pulmonary function and infection but not with weight, height, age, liver function, or degree of fat malabsorption. The presence of clubbing suggests appreciable pulmonary involvement. Most probably its progression indicates a deterioration in pulmonary state. In both instances increased efforts should be made to treat the infection.

Adolescent↗
PubMed1986

Essential element nutritional status in cystic fibrosis.

Serum calcium, magnesium, iron, copper and zinc were measured in 117 patients with cystic fibrosis. Apart from serum iron levels, all the other essential element levels were well maintained and there was no evidence of a need for supplementation. Serum iron was frequently low and the need for iron supplements must be considered after further investigation. The subjects studied covered a wide age range, had widely varying fat malabsorption and clinical grading, and also varying degrees of pulmonary involvement. We found no evidence that any of these parameters directly influenced essential element status as assessed by serum levels.

Adolescent↗
PubMed1986

The role of taste in dietary self-selection in rats.

In order to study the role of taste in dietary self-selection, rats were subjected to two degrees of gustatory deafferentation. The chorda tympani was sectioned alone or in combination with the glossopharyngeal nerve and the pharyngeal branch of the vagus. The animals chose from two diets, only one of which contained protein. After surgery, deficits were observed in body weight, food and water intake, and diet selection, proportional to the extent of deafferentation. Some 76% of the animals increased protein and decreased carbohydrate intake, but all rats continued to select a nutritionally balanced diet (Experiment 1). When subjected to a nutritional challenge of intragastric protein or carbohydrate supplementation, the rats compensated for calories and nutrients by selectively adjusting oral intake (Experiment 2). In saccharin preference tests, the preference as well as the total consumption of the test solutions was reduced (Experiment 3). The findings are contrasted to the effects of oral somatosensory deafferentation and are interpreted as a change in preference within the limits of metabolic requirements. The different roles/mechanisms of the two sensory systems in regard to dietary self-selection are discussed.

Animals↗
PubMed1985

Acquisition of dietary self-selection in rats with normal and impaired oral sensation.

To study the mechanisms of dietary self-selection, the dietary choice behavior of rats was observed for up to 5 weeks, beginning on the first day of exposure to two nutritionally different diets, a high-protein diet (44% protein) and a protein-free carbohydrate diet. In Experiment 1 normal rats selected equal amounts of the two selection diets at first and over a 7-day period gradually modified the choice ratio until a stable protein intake of 14.6% (SE,0.4) of total intake was reached. In Experiment 2 rats were subjected to partial trigeminal deafferentation, which impairs oral somatosensory input (touch, temperature, pain), before the two selection diets were introduced. The deafferented animals did not develop a stable selection pattern; their protein ratio varied over the entire possible range (0-44%) throughout the experiment. It is hypothesized that quantitative protein/carbohydrate selection involves an associative learning process in which somatosensory inputs from the feeding activity and/or from the properties of the food link dietary choice behavior to later metabolic consequences.

Animals↗
PubMed1985

Lithium-carbamazepine versus lithium-neuroleptic prophylaxis in bipolar illness.

Fourteen DSM-III diagnosed patients with lithium-resistant bipolar affective disorder treated with a combination of lithium and carbamazepine were followed in a lithium clinic for one year to study the prophylactic benefit and side effects of this drug regimen. Comparison data for the previous year on lithium and neuroleptics showed that for the 9 patients who completed the study, the lithium-carbamazepine regimen was superior to lithium-neuroleptics in decreasing the number of affective episodes and side effects. Carbamazepine blood levels appeared to be a possible contributing factor in the development of side effects.

Adult↗
PubMed1985

Intensive treatment of pseudomonas chest infection in cystic fibrosis: a comparison of tobramycin and ticarcillin, and netilmicin and ticarcillin.

Seventeen cystic fibrosis patients aged 3.1 years to 19.8 years had 30 courses of intensive treatment for relapse of their pseudomonas chest infection. The combination of netilmicin and ticarcillin was compared with tobramycin and ticarcillin in an open study. A significant subjective and objective improvement occurred in all patients. Pseudomonas was cleared temporarily from the sputum in 11 out of the 30 courses of treatment (37%). There was no significant difference between the netilmicin and tobramycin groups, nor evidence of sustained renal or ototoxicity. Intensive therapy of pseudomonas chest infection in cystic fibrosis patients is described in detail.

Adolescent↗
PubMed1985

The influence of long-term cimetidine as an adjuvant to pancreatic enzyme therapy in cystic fibrosis.

Seventeen patients on constant doses of pancreatic enzymes were randomised to receive either cimetidine or placebo for either of two successive six month periods. Nutritional state and maldigestion were assessed at the beginning and end of each period. Reductions in mean values of faecal fat, nitrogen, wet weight, and bile salts of approximately 30% were found on cimetidine therapy. Results showed considerable variation and only the fall in faecal fat was statistically significant. No benefit was demonstrated for height, weight, skinfold thickness, albumin, vitamin A, bone age or Crispin-Norman score.

Adolescent↗
PubMed1985

An exploratory study of delinquency, criminal offenses, and juvenile status offenses via the cross-validation design.

This article reports the results of an exploratory study of thirty variables that may have an effect on delinquency, criminal offenses, and juvenile status offenses. The study is based on secondary data, and the split-sample cross-validation procedure is used for analysis. Prediction equations were generated in Sample 1; Sample 2 was used for validation. In Sample 1, seven significant predictors of delinquency were found, five for criminal offenses, and five for juvenile status offenses. When these prediction equations were subjected to validation in Sample 2, the number of significant predictors was reduced from seven to four for delinquency, from five to four for criminal offenses, and from five to three for juvenile status offenses. The researchers interpreted these findings within the framework of the cross-validation procedure.

Adolescent↗
PubMed1984

Trigeminal sensorimotor mechanisms and ingestive behavior.

Selective section of trigeminal orosensory nerves was carried out to assess the contributions of trigeminal orosensation to the control of food and water intake in the rat. Trigeminal orosensory deafferentation reduces a responsiveness to food and water, disrupts jaw-opening and tongue protrusion reflexes mediating eating and drinking, impairs dietary self-selection and reduces the level of long-term body weight regulation. The magnitude of the feeding behavior deficits is a joint function of the extent of the denervation and the sensory properties of the diet, and recovery takes place along a palatability gradient. Analysis of feeding and drinking patterns and of learned instrumental behaviors indicates that deafferentation reduces the probability of initiating a feeding or drinking bout and profoundly disrupts performance of operant responses reinforced with food or water. We conclude that the trigeminal system contributes to both the sensorimotor and motivational control of ingestive behavior. Its motivational contributions differ in both kind and magnitude from those of the gustatory system.

Afferent Pathways↗
PubMed1984

Oral somatosensory factors in dietary self-selection in rats.

For studying the mechanisms of the control of protein intake, rats were subjected to partial trigeminal deafferentation. Oral somatosensory afferents from the lower anterior portion of the oral cavity were selectively sectioned, but somatosensation of the other parts of the mouth as well as gustatory and olfactory afferents were left intact. Animals were allowed to choose from two diets, only one of which contained protein. Before deafferentation, the rats chose a constant portion of their daily intake in the form of protein (12.2%; SE = 0.5). After deafferentation, protein intake was all but eliminated at first but was resumed later; carbohydrate intake was reduced. When total intake had recovered to nearly preoperative values, the protein/total-intake ratio remained impaired, with deficits that ranged from seemingly random selection to extreme preferences. The variability of dietary selection between days was considerably higher than before surgery. The discussion considers the involvement of learning processes in homeostasis.

Afferent Pathways↗
PubMed1984

Oral somatosensory factors in dietary self-selection after food deprivation and supplementation.

In order to study the role of oral somatosensory input in the ability of rats to adjust protein selection to changing metabolic conditions, trigeminally deafferented animals were subjected to nutritional stresses while being allowed to balance protein and carbohydrate intake from two separate dietary fractions. Partially trigeminally deafferented rats that had recovered a normal protein ratio (protein/total intake) underwent total food deprivation (Experiment 1) or intragastric (IG) supplementation of protein or carbohydrate suspensions (Experiment 2). In response to deprivation, control rats increased protein intake above ad-lib levels, but not carbohydrate intake. In response to IG supplementation, they decreased protein intake disproportionately more than carbohydrate intake when the fluid consisted of protein and vice versa when the fluid consisted of carbohydrate. The recovered deafferented rats showed no selective increase in protein intake after deprivation and no differential compensation to nutrient supplementation. This suggests that recovery of the protein ratio after partial trigeminal deafferentation is incomplete and that the compensatory mechanisms used cannot fully replace the function of trigeminal somatosensory input. The possible role of other orosensory and of postingestional factors for recovery is discussed.

Afferent Pathways↗
PubMed1984

Lithium-carbamazepine neurotoxicity and risk factors.

Five rapid-cycling manic patients developed neurotoxic syndromes when treated with a combination of lithium and carbamazepine, although all five had therapeutic plasma levels of both drugs. The risk factors for development of neurotoxicity with this drug combination are discussed.

Adult↗
PubMed1981

Trigeminal deafferentation and ingestive behavior in rats.

For studying the role of orosensory input in the control of ingestive behavior, rats were subjected to varying degrees of trigeminal deafferentation. Somatosensory branches that convey touch, temperature, and pain from the oral cavity were sectioned selectively, and innervation of the muscles of mastication and taste afferents were left intact. Severe intake deficits were produced, which included aphagia, adipsia, and prolonged hypophagia accompanied by a corresponding decrease in body weight. The deficits were proportional to the extent of deafferentation and were most severe when upper and lower portions of the mouth were affected. Although somatosensory impairment affected the organization of the consummatory response, all rats could bite, chew, and lick. Analysis of feeding patterns of minimally (mandibular) deafferented rats showed that the animals compensated for the consummatory inefficiency by increasing meal duration but failed to initiate meals at the normal rate, thus keeping food intake below normal levels. These results suggest that oral somatosensory input is critical for the mechanisms that regulate ingestive behavior.

Afferent Pathways↗