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Biomedical subjects

J M Weaver

Publications and source records attributed to J M Weaver.

48 records · Page 3Linked to original sources
PubMed1969

Growth factor requirements of Ruminococcus flavefaciens isolated from the rumen of cattle fed purified diets.

Eight strains of cellulolytic cocci were isolated from a 10(-8) dilution of rumen ingesta and were presumptively identified as Ruminococcus flavefaciens. Four strains were isolated from a steer fed a purified diet which contained isolated soy protein, and four strains were isolated from a steer fed a purified diet which contained urea. Certain growth factor requirements of these bacteria were determined. All strains grew with clarified rumen fluid added to the medium. However, fatty acids could substitute for rumen fluid in four strains. Two strains isolated from each steer either required or their growth was stimulated by isobutyric and/or isovaleric and/or 2-methyl-butyric acid. These results indicate that, even when a diet was fed which contained no branched-chain amino acids, the carbon skeleton precursors of branched-chain fatty acids, the cattle were still able to maintain a large population of cellulolytic bacteria that require fatty acids for growth. Therefore, the fatty acids appear to be provided by other bacteria, by protozoa, or by the host animal.

Amino Acids↗
PubMedDate not supplied

Comparison of the efficacy of esmolol and alfentanil to attenuate the hemodynamic responses to emergence and extubation.

STUDY OBJECTIVE: To define the ability of esmolol and alfentanil to control the hemodynamic changes associated with extubation and emergence. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: General surgery operating rooms at a university hospital. PATIENTS: Forty-two ASA physical status I and II patients without history of cardiac or pulmonary disease undergoing surgery not involving the cranium or thorax. INTERVENTIONS: Patients were given either a bolus dose of normal saline followed by an infusion of normal saline, a bolus dose of alfentanil 5 micrograms/kg followed by an infusion of normal saline, or a bolus dose of esmolol 500 micrograms/kg followed by an infusion of esmolol 300 micrograms/kg/min. MEASUREMENTS AND MAIN RESULTS: Emergency and extubation resulted in significant increases in heart rate (HR) and blood pressure (BP) in the placebo group. Alfentanil controlled the responses to emergence but prolonged the time to extubation (p < 0.05). Esmolol significantly controlled the responses to emergence and extubation (p < 0.05). CONCLUSIONS: Emergence and extubation after inhalation general anesthesia result in significant increases in BP and HR in healthy patients. An esmolol bolus dose and subsequent infusion significantly attenuated these responses. A small bolus dose of alfentanil minimized the responses to emergence but prolonged the time to extubation and was no longer protective at that point.

Adrenergic beta-Antagonists↗
PubMedDate not supplied

Fentanyl dosage.

Explore the source record for details and available documents.

Adolescent↗
PubMedDate not supplied

Comparative trial of succinylcholine vs low dose atracurium-lidocaine combination for intubation in short outpatient procedures.

Despite its many disadvantages, succinylcholine is the most commonly used drug for intubation of patients for short out-patient procedure. This double blind trial compared a low dose atracurium/lidocaine combination to succinylcholine for intubation in 40 ASA1 adult patients. Low dose atracurium/lidocaine provided clinical intubating conditions at two minutes and cardiovascular stability equivalent to succinylcholine with significantly less myalgia. Spontaneous respiration was slower after low dose atracurium/lidocaine relative to succinylcholine. Low dose atracurium/lidocaine may provide an acceptable alternative to succinylcholine for intubation in short outpatient procedures.

Adult↗
PubMedDate not supplied

A visual analogue scale in the assessment of dental anxiety.

The purpose of this study is to determine the validity of the visual analogue scale (VAS) in the assessment of changing levels of dental anxiety, through correlation with the dental anxiety scale (DAS) and the state portion (A-state) of the statetrait anxiety inventory (STAI). Forty-five adult patients attending an oral surgery clinic for a routine dental extraction participated. Before any treatment, each patient completed the DAS, the STAI, and a 100mm VAS. The order of administration was randomly determined. Following completion of the dental extraction under local anesthesia and just before discharge, the patients were once more asked to complete the DAS, the A-State, and a VAS which were again randomly ordered. All three measures demonstrate a significant reduction in mean anxiety scores from presurgery to postsurgery. There are significant correlations among the three measures both pre- and postsurgery. The VAS appears to correlate well with both the DAS and the A-State under changing levels of anxiety.

Adult↗
PubMedDate not supplied

Relationship of tonsil size on an airway blockage maneuver in children during sedation.

A previous report suggested that airway compromise without self-correction may occur in pediatric dental patients sedated with chloral hydrate (CH) and nitrous oxide (N2O) and may be interpreted as "deep" sedation. The purpose of this institutionally approved study was to determine 1) the association between the size of the tonsils and 2) the degree of expired carbon dioxide (CO2) and oxygen saturation (SaO2) changes to simulated airway obstruction using the Moore head-tilt maneuver for 30 sec or less. Thirty healthy children (ASA I), aged 22-40 months, were evaluated for tonsil size and sedated with CH (50 mg/kg) and hydroxyzine (2 mg/kg) and supplemented with N2O. Pulse oximetry and capnography were used to monitor the child. During the restorative phase when the patient appeared asleep, the head was rolled forward with the chin touching the chest for a period of 30 sec. Changes in SaO2 and CO2 waveform were observed during this period. The results indicated that seven children who had enlarged tonsils had blocked airways (as determined by capnography) lasting approximately 15 sec. The remaining children did not have enlarged tonsils and continued to exchange air appropriately. O2 levels did not change during this period. The results suggest that the likelihood of airway blockage increases with enlarged tonsils. In children without airway blockage, ventilation occurs unimpeded, and attempts to readjust the head may not occur. The association between airway blockage and patient responsiveness is discussed in relation to sedation levels.

Airway Obstruction↗