Herbal medications in the Physician's Desk Reference.
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Formularies as Topic↗
Biomedical subjects
C H Lawyer
Publications and source records attributed to C H Lawyer.
Comparison of staged thoracoscopy and median sternotomy for lung volume reduction.
BACKGROUND: Lung volume reduction operations have proved beneficial for emphysematous patients, but questions remain about the role of a unilateral procedure. METHODS: Fifty patients were prospectively enrolled in a lung volume reduction surgery program for emphysema with staged unilateral video-assisted thoracoscopic procedures (VATS group). These patients were compared with 29 patients having bilateral lung volume reduction procedures by median sternotomy. RESULTS: The VATS group was slightly older and had shorter 6-minute walk distances, but otherwise the two groups were similar. Hospital stays were shorter for each unilateral VATS procedure, but the total of the two hospital stays was longer than the stay for the sternotomy group (21.1 versus 14.8 days). Complications were comparable, there were no in-hospital deaths, and there was significant difference in the 1-year mortality rate (VATS, 6% versus sternotomy, 13.8%; p = 0.137). Functional test results were comparable between the groups with improvements in percent predicted forced expiratory volume in 1 second (VATS, 41%, and sternotomy, 40%), 6-minute walk distances (VATS, 48%, and sternotomy, 26%), dyspnea scores, and acid base measurements. CONCLUSIONS: Staged lung volume reduction operations do not appear to offer any measurable advantages over a single hospitalization and bilateral lung volume reduction procedures.
Aged↗
The CorA magnesium transporter gene family.
The CorA transport system is the primary Mg2+ influx system of Salmonella typhimurium and Escherichia coli. The CorA protein has no homology to any other known family of proteins. It has an unusual membrane topology, with a large, soluble, highly charged periplasmic N-terminal domain with three transmembrane segments in a shorter, hydrophobic C-terminal domain. Previous phenotypic and molecular data had suggested that this transport system was widespread in the Bacteria. In this report we show that CorA is virtually ubiquitous in the Bacteria and Archaea, forming a distinct family of transport proteins. Genomic sequences to date have revealed at least 22 members of the CorA family in the Bacteria and the Archaea, with 6 more distant members in the yeasts. Only three of the smallest bacterial genomes lack a CorA homologue. Strikingly, phylogenetic analysis does not show clustering by related species or even within kingdom. Several species of Bacteria contain two or even three CorA paralogues. Within species, these paralogues are not closely related, however, and we suggest that they might have distinct transport functions. A multiple alignment suggests three extended consensus regions within the N-terminal soluble domain of CorA, which is predicted to be virtually all alpha-helical. A fourth consensus region includes the last 20 residues of the soluble domain and continues through the entire membrane domain. The first half of this last consensus domain may form an amphipathic alpha-helix that extends from the soluble domain into the first transmembrane segment. The degree of charge in the first transmembrane segment is quite variable, and we suggest that this transport family may include members with only two rather than three transmembrane segments. If so, this would place the N-terminal soluble domain on different sides of the membrane in different members of the family. We suggest that the CorA Mg2+ transport system forms the major Mg2+ uptake system in the Bacteria and Archaea but that some family members may have a function other than Mg2+ transport.
Amino Acid Sequence↗
2-Hydroxymethyl-3,4-dihydroxy-6-methyl-pyrrolidine (6-deoxy-DMDP), an alkaloid beta-mannosidase inhibitor from seeds of Angylocalyx pynaertii.
A polyhydroxy alkaloid has been isolated from the seeds of the African legume Angylocalyx pynaertii and identified as a 2-hydroxymethyl-3,4-dihydroxy-5-methylpyrrolidine by ms and 1H- and 13C-nmr spectroscopy. The absolute stereochemistry was established, by a stereochemically unambiguous synthesis from diacetone glucose, as 2,5-imino-1,2,5-trideoxy-D-mannitol, which may also be regarded as 2R,5R-dihydroxymethyl-3R,4R-dihydroxypyrrolidine (DMDP) [2] in which a hydroxymethyl group is deoxygenated, i.e., 6-deoxy-DMDP [1]. Whereas the structurally related polyhydroxypyrrolidine alkaloids which have previously been discovered are inhibitors of alpha- and beta-glucosidase, 6-deoxy-DMDP is unique in inhibiting beta-mannosidase. In addition to this novel alkaloid and 2-hydroxymethyl-3,4-dihydroxypyrrolidine [3], previously shown to be present in several Angylocalyx species, the known piperidine alkaloids deoxymannojirimycin [4] and fagomine [5] were identified for the first time as constituents of An. pynaertii seeds.
Alkaloids↗
Cardiovascular effects of an exercise program: a controlled study among firemen.
Twenty-seven firemen were divided into three groups. Group a performed one hour of unsupervised exercise three to four times per week. Group C performed similar but supervised exercise, and group B had no exercise program. After 12 weeks group A showed an average increase of 19% in maximal oxygen uptake (VO2 max); group C, an average increase of 20%; and group B, an average decrease of 2%. One-minute postalarm heart rates showed a correlation with VO2 max (p = 15). A serious cardiac arrhythmia was found in the oldest fireman. Careful physical screening followed by an on-the-job exercise program increases aerobic reserve. We suggest that postalarm tachycardia is dampened. This may lessen the risk of heart disease occurring in the postalarm period.
Adult↗
Utilization of intravenous dihydroxypropyl theophylline (dyphylline) in an aminophylline-sensitive patient, and its pharmacokinetic comparison with theophylline.
The pharmacokinetics and urinary excretion of intravenously administered 7-(2,3-dihydroxypropyl) theophylline (dyphylline), were studied in a 37-yr-old asthmatic woman with ethylene diamine sensitivity who manifested intolerance to intravenous aminophylline on three separate occasions. In this subject, intravenously administered dyphylline was tolerated very well and was effective in the subsequent management of acute bronchospastic episodes. Dyphylline was significantly concentrated in the urine. This, coupled with its rapid clearance, suggests potential clinical application in patients with hepatic dysfunction. Though aminophylline sensitivity is rare, ethylene diamine sensitivity should be considered in untoward reactions to this drug.
Adult↗
Application of the two-compartment open model with Michaelis-Menten elimination kinetics to valproic acid in the bile-exteriorized rat.
The concentration profile of valproic acid (VPA) in bile-exteriorized rats given an i.v. bolus of 15 mg sodium valproate (NaVPA) per kg has been previously shown to exhibit a limited distribution phase and first-order elimination kinetics (two-compartment open model). At a higher dose of 150 mg NaVPA/kg, the initial elimination was non-linear (capacity-limited). Using an 'iterative modified Euler integration technique,' the results have been fitted to a pharmacokinetic model which allows for both two-compartment redistribution of drug as well as saturable Michaelis-Menten elimination kinetics. A combined pharmacokinetic model of this type has not been previously described.
Animals↗
New method that gives true least squares fit of one and two compartment open pharmacokinetic models applied to valproic acid and methadone.
Methods for obtaining an exact least squares fit of the one and two compartment models have not been previously described. The multi compartment polyexponential pharmacokinetic models have classically been fit to data using nonlinear regression programs such as NonLin (Metzler, 1969). The two compartment open model, for example, can be fit to least squares regression with equation 1 by iteratively varying A, alpha, B, and beta. Y = Ae(-alpha t) + Be(-beta t).
Animals↗
Materno-fetal pharmacokinetics and fetal distribution of valproic acid in a pregnant rhesus monkey.
Chronic indwelling catheters in the maternal femoral artery and vein, fetal carotid artery and jugular vein, and amniotic cavity of a pregnant rhesus monkey permitted administration of sodium valproate (NaVPA) and collection of timed samples of maternal and fetal blood and amniotic fluid. After a single IV dose (50 mg/kg) to the mother, a rapid distribution phase (t1/2 alpha = 0.5 minute) was followed by a biphasic decline in concentration in maternal blood (t1/2 beta = 31 minutes, t1/2 gamma = 390 minutes). VPA appeared rapidly in fetal blood, reached a concentration slightly higher than in maternal blood by 15 minutes, and thereafter declined in parallel with the concentration in maternal blood. Terminal fetal/maternal ratios of blood concentration of VPA were about 1.3. Similar patterns of decline were observed after NaVPA was given IV to the fetus. A multicompartment first-order materno-fetal pharmacokinetic model is presented. Tissue distribution studies in the fetus showed that VPA concentration was highest in blood; moderate in heart, liver, spleen, kidney, and skeletal muscle; and low in brain.
Amniotic Fluid↗