PubMed Health⌕ Search

Biomedical subjects

R M Gardner

Publications and source records attributed to R M Gardner.

At least 181 records · Page 10Linked to original sources
PubMed1980

Selection of the best spirometric values for interpretation.

Selection of spirometric test values for reporting and interpretation has recently received considerable attention. In 1977, the American Thoracic Society (ATS) Snowbird Workshop on Standardization of Spirometry recommended that the maximal values for FVC and FEV1 be used for clinical interpretation, even if they came from different spirometric tracings. The Intermountain Thoracic Society (ITS) had recommended in 1975 that FVC and FEV1, be reported from the single tracings, using the largest sum of FVC plus FEV1 (best test). We evaluated the results of 1,853 spirometric test sessions in 1,101 subjects (923 hospital patients and 178 normal volunteers). The mean difference between the 2 test selection methods cited above was 5.8 ml for FVC and 8.4 ml for FEV1. In 98.4% of the FVC comparisons and 95.7% of the FEV1 comparisons, the differences were within the minimal instrument accuracy standard (+/- 50 ml or +/- 3% of the reading) suggested by the ATS. Differences between maximal and best test FVC and FEV1 were small. The selection of values for interpretation from the best test did not compromise accuracy, and was a simpler and more practical method for reporting clinical spirometric results.

Adult↗
PubMed1978

Increased cyclic GMP in the end-plate region of denervated frog muscle.

Denervated frog sartorius muscles showed an approximately 2--3 fold increase of cyclic GMP in their end-plate rich regions which did not appear up to 5 weeks after denervation in the normally end-plate-free pelvic region. No increase in cyclic AMP was seen in these preparations. The results suggest that the increase of cyclic GMP is related to processes specific to the region in which end plates are normally present.

Acetylcholine↗
PubMed1978

Regulation of the uterine response to estrogen by thyroid hormone.

After estradiol (E2) administration, early increases (within 4 h) in uterine wet weight and the synthesis of 2-deoxyglucose-6-phosphate from 2-deoxyglucose are similar in ovariectomized rats and in ovariectomized rats made hypothyroid by feeding a low iodine diet containing prophylthiouracil. Most late uterine responses occurring 24 h after E2 treatment, however, are greatly diminished in the hypothyroid animals. The diminished responses include increases in uterine wet weight, dry weight, protein content, RNA content, and the incorporation of thymidine into uterine DNA. One response, the synthesis of 2-deoxyglucose-6-phosphate from 2-deoxyglucose is not diminished in hypothyroid rats 24 h after E2 treatment. The diminished uterine response is not due to a shift in the dose-response curve for E2, but results from a decrease in the magnitude of the maximum uterine response. Treatment of hypothyroid rats with exogenous T3 restores the diminished uterine response in a dose-dependent and time-dependent manner. A dose of 0.5 microgram T3/100 g BW for 5 days restores the response completely, while 48-72 h of treatment with higher doses of T3 are required to restore the response. The effect of T3 is not mediated by the pituitary, since exogenous T3 restores diminished uterine responses in ovariectomized, hypophysectomized animals. These results suggest that thyroid hormones may have a direct effect on the uterus which regulates the responsiveness of the organ to E2.

Animals↗
PubMed1978

Selective blockade of estrogen-induced uterine responses by the antiestrogen nafoxidine.

The response of the immature rat uterus to the antiestrogen, nafoxidine (Upjohn U-11, 100A), is maximum at a dose of 5 micrograms. This dose of nafoxidine sustains the uterine response for at least 72 h. After treatment with 5 micrograms nafoxidine for 24 h, uterine cytosol contains approximately one half the total number of estrogen receptors originally present in uteri of untreated animals, and uterine nuclei also contain approximately one half the receptors originally present in unstimulated tissue. The total amount of uterine estrogen receptor, however, is not altered 24 h after treatment with nafoxidine relative to saline-treated controls, while estradiol treatment doubles the total amount of receptor relative to controls. Pretreatment with 5 micrograms nafoxidine for 24 h does not block the uterine response occurring 4 h after the subsequent administration of estradiol, but does block the uterine response occurring 24 h after the subsequent administration of estradiol. These results suggest that uterine nuclei contain different acceptor sites for regulating short term and long term uterine responses to estrogen.

Animals↗
PubMed1977

Safety and efficacy of continuous flush systems for arterial and pulmonary artery catheters.

Air embolism and static pressure errors have been attributed to continuous infusion systems. Experiments show that the primary source of air bubbles in such a system is the drip chamber. A drip chamber that minimizes this problem was tested and is recommended. Pressure errors due to the flush system are shown to be clinically insignificant. Fast flushing through a central arterial catheter is shown to be a minimal hazard.

Arteries↗
PubMed1977

Rebreathing pulmonary capillary and tissue volume in normals after saline infusion.

A rebreathing technique was utilized to assess changes in diffusing capacity (DCO), pulmonary capillary blood volume (Vc), pulmonary parenchymal tissue volume (Vt), and cardiac output (Qc), after infusion of 2 liters of 0.9% saline intravenously in 13-25 min in five healthy subjects. Blood hemoglobin concentration decreased an average of 17%. Vc increased strikingly in all five subjects. No significant changes in Vt, or in Vt per unit lung volume were observed. Radiographic evidence of interstitial pulmonary edema was present in four of the five subjects. Radiographic total lung capacity was reduced significantly in four of the five subjects. Significant reductions in forced vital capacity (FVC), forced expiratory volume in 1.0 and 3.0 s, and mean forced expiratory flow during the middle half of the FVC occurred in three of the five subjects. No dyspnea, cough, or physical examination abnormalities of lungs or heart occurred. This noninvasive, ventilation-limited, rebreathing technique appears capable of detecting early changes in pulmonary congestion, at a time when definitive radiographic changes and changes in the physical examination are absent. It appears capable of detecting the increase in Vc associated with hypervolemia in man.

Adult↗
PubMed1976

Effect of acetylcholine on glycogen phosphorylase activity and cyclic nucleotide content in isolated perfused rat hearts.

Acetylcholine (1muM) increased cyclid GMP content in paced perfused rat hearts within 15 sec., with peak content occurring at 1 min. No effect of acetylcholine on cyclic AMP content, phosphorylase activity or glycogen synthase was observed. Epinephrine (1muM) infusion increased both cyclic AMP content and phosphorylase, but did not alter cyclic GMP content or glycogen synthase activity. When acetylcholine was infused during the second min. of a 2 min. infusion of epinephrine, the cholinergic agent increased cyclic GMP and reduced the stimulated phosphorylase activity and elevated cyclic AMP.

Acetylcholine↗
PubMed1976

Regulation of cyclic nucleotide levels and glycogen phosphorylase activity by acetylcholine and epinephrine in perfused rat hearts.

Acetylcholine (ACh) produced a time and dose-dependent increase in cyclic 3',5'-guanosine monophosphate (cyclic GMP) levels in perfused rat hearts without any significant (P greater than .05) change in cyclic 3',5'-adensoine monophosphate (cyclic AMP) level or glycogen phosphorylase activity. Epinephrine produced a dose-dependent increase in both cyclin AMP and phosphorylase activity but no significant (P greater than .05) change in cyclic GMP levels. When ACh (10(-6) M) was infused into hearts during the infusion of epinephrine (10(-6) M), a time-dependent increase in cyclic GMP and decrease in cyclic AMP occurred, both of which preceded a significant (P less than .05) decrease in glycogen phosphorylase activity. In epinephrine-stimulated hearts, ACh produced a dose-dependent increase in cyclic GMP levels. Similar concentrations produced a fall in cyclic AMP levels and phosphorylase activity. No condition tested resulted in a significant (P greater than .05) change in glycogen synthase activity. It is concluded that ACh can reduce cyclic AMP levels and phosphorylase activity only when they have been elevated above basal values. These changes are associated with an increase in cyclic GMP. The reduction in phosphorylase produced by ACh may be the result of either or both of the changes in cyclic nucleotide levels.

Acetylcholine↗
PubMed1976

Computerized medication monitoring system.

A computerized medication monitoring system for alerting and warning of potential adverse drug reactions is described. The system integrates computerized data on each hospital patient (medications, clinical laboratory, blood gas, ECG, ALLERGIES, DIAGNOSIs, etc.) and returns to the pharmacist warning messages and suggestions regarding patient drug therapy. The broad data base allows for nearly complete drug therapy monitoring. When a warning message is received, the pharmacist contacts the physician or nursing staff and explains the potential problem. The system also generates prescription labels and patient drug profiles which are used in a unit dose dispensing system. Five percent of 13,727 patients monitored have had drug alerts. Of these alterts, 44.9% were drug-laboratory contraindications and only 28.9% were drug-drug interactions. Of the 690 alerts received, 77% resulted in the physician changing the patient's therapy.

Computers↗
PubMed1975

Pupillary changes during encoding, storage, and retrieval of information.

6 subjects were each auditorily presented six lists of 7-digit numbers for retention intervals of 0, 5, and 10 sec. Pupil size was recorded during stimulus presentation, retention, interval, and recall of items. Results indicated that pupil dilation occurred during encoding and retrieval of stimulus items. Pupillary constriction was found during the retention interval when rehearsal was presumed to occur.

Acoustic Stimulation↗