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Biomedical subjects

W C Miller

Publications and source records attributed to W C Miller.

At least 109 records · Page 6Linked to original sources
PubMed1984

Adaptations to a high-fat diet that increase exercise endurance in male rats.

Eighty-seven male Sprague-Dawley rats (245-300 g) were randomly assigned to one of two experimental groups. The first group consumed a diet high in fat and low in carbohydrate (LCD), whereas the second group ate a normal diet (ND). After either 1 or 5 wk on the diets, rats from each group were killed either before or after an exhausting run on a rodent treadmill (35 m X min-1, 0% grade). The LCD animals ran significantly longer before exhaustion at both week 1 (44.9 +/- 5.1 vs. 41.6 +/- 4.2 min) and week 5 (47.1 +/- 3.6 vs. 35.5 +/- 3.1 min) (P less than 0.05). Adaptations to the LCD included lower muscle and liver glycogen content, decreased rate of glycogen breakdown during exercise, decreased lactate production, and elevated blood ketone levels. In addition to these substrate changes, the LCD caused increased enzyme activities of muscular 3-hydroxyacyl-CoA dehydrogenase (35-110%) and citrate synthase (15-20%). These data indicate that rats exposed to a high-fat diet are capable of prolonged intense exercise in spite of limited glycogen stores. This improved capacity for exercise appears to be partially the result of muscular adaptations to the diet, which apparently increase the ability to oxidize fat and concomitantly spare glycogen.

3-Hydroxybutyric Acid↗
PubMed1984

Enlarged pulmonary arteriovenous vessels in COPD. Another possible mechanism of hypoxemia.

Among 27 patients with moderate-to-severe chronic obstructive lung disease, 22 had anatomic intrapulmonary shunting greater than that seen in normal subjects. The shunted blood passed through enlarged pulmonary vessels, as demonstrated with particles 10-90 microns in diameter. The shunt magnitude was correlated with the decrement in lung diffusing capacity. It did not correlate well with pulmonary mechanical abnormalities such as air flows and volumes or resting blood gas data. Nevertheless, shunting through enlarged pulmonary vessels may play a role in the hypoxemia seen in COPD patients, especially at exercise.

Aged↗
PubMed1984

Effect of dietary fat on food intake, growth and body composition in rats.

The long-term ingestion of a fat-rich diet caused severe obesity in adult rats. Severe obesity developed in these animals without them having to increase caloric intake. Evidence for this comes from the observation that voluntary intake averaged 36,113 +/- 410 calories/rat per 60 wk for rats eating a high-fat diet (42% of calories from fat) compared to a value of 36,125 +/- 500 calories/rat per 60 wk for those eating a diet of Purina chow. Despite a similar caloric intake, carcass fat averaged 51 +/- 1% for rats eating the fat-rich diet but only 30 +/- 1% body fat for control animals eating the low-fat diet of Purina chow. These results indicate that a fat-rich diet does not always cause rats to overeat. Further, they clearly demonstrate that severe obesity can develop in the absence of hyperphagia provided the animals eat a fat-rich diet. Finally, a correlation coefficient of r = 0.76 between body weight and lean body mass was obtained for the Purina chow-fed rats and that of r = 0.66 was obtained for the fat-fed rats.

Animals↗
PubMed1984

A double-blind comparison of the efficacy and safety of lorazepam and diazepam in the treatment of the acute alcohol withdrawal syndrome.

The safety and efficacy of lorazepam and diazepam were compared in the treatment of the acute alcohol withdrawal syndrome during a five-day double-blind trial in alcoholic patients. The daily doses of lorazepam and diazepam were tapered from 6 or 8 mg to 2 mg and from 30 or 40 mg to 10 mg, respectively, during the first four days; no medication was given on day 5. Drug efficacy was measured by Total Severity Assessment Scores (TSAS), the three TSAS factor scores, and by the physician's global evaluation. Of the 55 inpatients enrolled, 47 completed the study. There were no statistically significant differences between the treatment groups in any of the efficacy assessment measures. The physical conditions of the majority of the patients treated with lorazepam (57%) and diazepam (59%) improved during therapy. There were no clinically significant differences between the treatment groups in vital signs or laboratory values. The results of this study indicate that lorazepam is as effective as diazepam in reducing the symptoms of acute alcohol withdrawal. When lorazepam and diazepam are compared in terms of their pharmacokinetics, lorazepam may have therapeutic advantages for the management of the acute alcohol withdrawal syndrome.

Adult↗
PubMed1982

Temporal stability of the Experienced Control Scale within an alcoholic male population.

Several reports have suggested relations of alcohol abuse to level of control experienced over various life pressures or forces. This study assessed test-retest reliability of the Experienced Control Scale (EC) (Tiffany, 1967) within a male alcoholic sample. The EC was completed on two occasions 1 week apart by 48 inpatients on an alcoholism treatment unit. Resulting test-retest reliability coefficients were .57 for the Internal ratio score, .79 for the External ratio score, .72 for the sum of the two ratio scores, and from .56 to .69 for the four basic scores used in computing ratio scores. Intellectual ability as assessed by the Shipley Institute of Living Scale was unrelated to EC scores and occasionally but conflictingly related to temporal stability of EC scores. Neither age nor education showed a significant relationship to temporal stability of the EC or to ratio scores. Implications of findings for clinical and research applications of the EC are discussed, particularly support for combining the ratio scores rather than treating them separately. Possible determinants of the obtained stability of the EC also are explored.

Adaptation, Psychological↗
PubMed1982

Disulfiram acceptors and refusers: do they differ?

The present study examined possible personality and mood state correlates of alcoholics' decisions to accept or refuse disulfiram (Antabuse) as past of their treatment program. Subjects were 104 male veterans in an inpatient alcohol treatment program who were offered disulfiram after detoxification and evaluation. All subjects completed the Minnesota Multiphasic Personality Inventory, the Profile of Mood States, and the State-Trait Anxiety Inventory. Subjects were classified as acceptors (n = 78) or refusers (n = 26) based on their response to staff encouragement to undergo a trial of disulfiram. There were no significant group differences on age, racial composition, or any of the personality or mood state measures, with the exception of a trend (p less than .06) for acceptors to score higher than refusers on the masculinity-femininity scale of the MMPI. Examinations of distributions of MMPI profile code types similarly showed no differences between the two groups. Possible contextual explanations of these results are examined. Findings offer no support for the assumption that agreement to take disulfiram signifies greater motivation or intention to remain abstinent.

Alcoholism↗
PubMed1982

Efficacy of a new hygroscopic condenser humidifier.

A newly designed hygroscopic condenser humidifier was evaluated to assess efficacy of providing moisture to the airways in patients whose upper airways had been bypassed. With its use, the relative humidity of inspired gas fell with both increasing tidal volumes and especially increasing F10(2) due to the intrinsic dryness of medical oxygen. Under conditions other than high volumes and inspired oxygen, humidification appeared adequate. The device obviated many complications encountered with conventional heated nebulizers. It does add some degree of resistance in the ventilatory circuit which might be stressful during spontaneous breathing.

Evaluation Studies as Topic↗
PubMed1981

Flow-dependence of extravascular thermal volume as an index of pulmonary edema.

Using a double indicator (dye and heat) dilution technique of extravascular lung water measurement, we examined the effect of a reduction in cardiac output and positive pressures on the extravascular thermal volume (EVTV) in dogs. Following baseline EVTV measurements, cardiac output was lowered by inflation of balloons in the superior and inferior vena cavas, as well as by bleeding, and positive pressures were applied to the airways. There was good agreement between the baseline EVTV and post-mortem lung water; however, as the cardiac output was lowered there was a reduction in the measured EVTV. In other animals following application of positive airway pressure there was a decrease in the EVTV which appeared to be related to the reduction in cardiac output caused by positive airway pressure. At least in part, loss of thermal indicator appeared to explain the reduction in EVTV. Measurement of EVTV as an index of pulmonary edema may not be accurate in the face of a changing cardiac output.

Animals↗
PubMed1981

Effect of methylprednisolone on experimental noncardiogenic pulmonary edema.

Methylprednisolone, 30 mg/kg body weight, was given to dogs 30 min and 4 h after injection of monocrotaline to produce noncardiogenic pulmonary edema. Control animals received monocrotaline but not corticosteroids. After 6 h the steroid-treated animals demonstrated significantly butter gas exchange and significantly less pulmonary edema. A possible mechanism of this beneficial effect of steroids is inhibition of complement-leukocyte interactions which may mediate pulmonary microvascular injury. The results lend some support to the clinical practice of short-term pharmacologic doses of steroids in noncardiogenic pulmonary edema.

Animals↗
PubMed1981

Airway response to inhaled histamine in asymptomatic long-term marijuana smokers.

Bronchial challenge with histamine was used to assess bronchial reactivity in asymptomatic individuals who were long-term social smokers of marijuana. Their reactivity was compared to that of nonsmokers and asthmatics. Spirometry results were normal in the marijuana users. There was no significant difference in bronchial reactivity between marijuana smokers and nonsmoking controls, whereas the asthmatics demonstrated the expected hyperreactivity. These observations suggest that customary social use of marijuana may not produce abnormalities in airway function detectable by spirometry or bronchoprovocation.

Administration, Intranasal↗
PubMed1981

Pulmonary diffusing capacity in chronic renal failure.

Reduced carbon monoxide diffusing capacity (DLCO) is a frequent and often isolated pulmonary physiological abnormality in patients with chronic renal failure. In 20 patients with chronic renal failure who had normal spirometry (FEV1 and FVC greater than 80% of predicted) and near normal chest roentgenograms (three had mild cardiomegaly), the DLCO was significantly reduced compared to values obtained from 25 healthy laboratory staff and renal transplant donors. DLCO and diffusing capacity standardized for alveolar volume (KCO) remained reduced after correction for anaemia. No relationship between anaemia and severity of reduction of DLCO was demonstrated. These observations suggest that in addition to anaemia and ventilatory abnormalities, there may be other factors causing a reduced DLCO in chronic renal failure.

Adult↗
PubMed1981

Effect of PEEP on lung water content in experimental noncardiogenic pulmonary edema.

After administration of monocrotaline to dogs to produce noncardiogenic pulmonary edema, one-half of the animals (controls) were treated with intermittent positive pressure breathing (IPPV), and one-half with that ventilation plus the addition of 10 cm H2O of positive end-expiratory pressure (PEEP). After 6 h, the animals treated with PEEP demonstrated significantly better arterial oxygenation and reduced AaDO2, but lung water, quantitated either postmortem or in vivo by indicator-dilution techniques, was no less than controls. Although PEEP improves gas exchange, it fails to modify the degree of pulmonary edema represent.

Animals↗
PubMed1981

Thoracic computed tomography in the critically ill patient.

Thoracic computed tomography (CT) was performed on 19 ICU patients to define chest abnormalities not clearly seen on conventional portable chest radiographs. In five (26%) of these cases, the CT demonstrated new findings that substantially altered the patient's course including malpositioned thoracostomy tubes, loculated pleural fluid, unsuspected pneumothorax, and pericardial effusion. In selected cases, thoracic CT can provide precise definition of intrathoracic problems in the critically ill patient.

Adolescent↗
PubMed1981

Closing volumes with variations in pulmonary capillary wedge pressure.

Increased closing volumes have been documented in patients in whom there was suspected to be early pulmonary edema due to increased pulmonary capillary wedge pressure. However, the relationship between the actual pulmonary capillary wedge pressure and closing volume has not been established. To attempt to define this relationship and to determine whether the closing volume might be a useful indicator of the onset of pulmonary edema, we measured the closing volume in dogs while sequentially increasing the pulmonary capillary wedge pressure by way of a left atrial balloon. We found a small but significant increase in closing volume (p less than 0.01) when a pulmonary capillary wedge pressure of 25 mm Hg was achieved, and it was at this pressure that pulmonary edema would hypothetically be expected to begin.

Animals↗
PubMed1981

Levels of angiotensin-converting enzyme in pleural effusion.

The value of determining the angiotensin-converting enzyme (ACE) in serum has been clearly established, particularly in sarcoidosis, but is significance in pleural effusions is practically unknown. In the present study, ACE level was determined in the pleural fluid of 18 hospitalized patients along with the values for total protein, lactic acid dehydrogenase (LDH), complete and differential cell counts and cytology. The ACE level was higher in exudates than in transudates and paralleled closely the total protein level in the pleural fluid. There was no correlation between ACE and LDH levels and either WBC or RBC counts in the effusions. The ACE levels failed to discriminate between benign and malignant diseases or to correlate with any specific etiology for the effusion. There was a significant gradient between ACE levels that were higher in the serum than in the effusion of all nine patients in whom both were measured. The filtration coefficient (ratio of pleural fluid to serum concentration of a protein) of ACE was less than that of total protein and was compatible with ACE penetration in the pleural fluid by a process of diffusion.

Humans↗