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PubMedDate not supplied

The AaDO2 and venous admixture at varying inspired oxygen concentrations in chronic obstructive pulmonary disease.

The alveolar to arterial oxygen pressure difference (AaDO2) and pulmonary venous admixture (Qs/Qt) were measured in 32 patients with chronic obstructive pulmonary disease during right heart catheterization at inspired oxygen concentrations (FIO2) of 21, 24, 28, 35, and 40%. Patients without chronic hypercapnia (PaCO2 is less than 45 torr, group A) had Qs/Qt less than 25% while breathing room air; their AaDO2 rose at a rate of 3 torr for each percent increase in FIO2. In those with chronic hypercapnia (PaCO2 greater than 44 torr., (group B), THE Qs/Qt was always greater than 24% during air breathing and the AaDO2 rose at a rate of 5 torr for each percentage increase in FIO2. These changes should be considered in the interpretation of the AaDO2 in patients with COPD in whom the FIO2 is changed during the course of therapy. The Qs/Qt fell curvilinearly with increasing FIO2 but the rates of fall were quantitatively different in groups A and B. A physiological explanation for the changes in Qs/Qt and ADO2 which result from changes in FIO2 is presented.

Arteries↗
PubMed1975

Changes of EEG and pulmonary venous admixture during a protein load in patients with cirrhosis.

21 patients with cirrhosis of the liver and 24 control patients were studied before and after a protein load (120 g protein per day during one week). An EEG was recorded and a visual assessment of frequency pattern was performed. Venous admixture was estimated during hyperoxia. According to the EEG frequency pattern the patient group with cirrhosis was subdivided into those with EEG slowing after the protein load (n = 7) and those without (n = 14). The following results were obtained: 1) Resting arterial blood gases did not change in either group. 2) There was a significant increase of the AaD02 (difference between alveolar p02 and peripheral arterial p02) in cirrhotics and controls. 3) The increase in AaD02 was significantly larger in those cirrhotics showing EEG slowing compared to those without EEG - slowing or to the controls. 4) Fractional venous admisture increased significantly in those cirrhotics showing EEG slowing. There was no significant change in those patients who did not show EEG changes or in the controls.

Blood Pressure↗
PubMed1976

Oxygen transport and venous admixture in the extremely obese. Influence of anaesthesia and artificial ventilation with and without positive end-expiratory pressure.

Eight extremely obese patients (mean weight 136 kg) were studied when awake and breathing air, and during anaesthesia with controlled ventilation (oxygen fraction in inspirate (FIO2): 0.5). During anaesthesia, the atients were first studied with zero end-expiratory pressure (ZEEP) ventilation. Then two different positive end-expiratory pressures (PEEP) were applied, 10 cmH2O and 15 cmH2O, in order to study the effect of an increase in functional residual capacity (FRC). Arterial oxygenation and oxygen availability, as well as cardiac output (QT) and venous admixture (QS/QT) were studied. With the institution of anaesthesia and ZEEP, the alveolar arterial oxygen tension difference (P(A-a)O2) rose from 3.5 +/- 1.1 to 28.4 +/- 2.6 kPa, and the oxygen availability fell from 1346 +/- 222 to 1039 +/- 239 ml/min, due to the additive effect of an increase in QS/QT from 10 +/- 4 to 21 +/- 5% and a fall in QT, from 7.7 +/- 1.2 to 5.5 +/- 1.1 1/min. With increasing levels of PEEP, despite a fall in P(A-a)O2, there was a reduction in oxygen availability. This was due to simultaneous reduction in QS/QT and QT. At a PEEP of 15cmH2O, the P(A-a)O2 was 21.2 +/- 7.1 kPa, oxygen availability 862 +/- 170 ml/min, QS/QT 13 +/- 4 and QT 4.4 +/- 0.6 1. It is concluded that PEEP ventilation significantly reduces QS/QT in extremely obese patients during anaesthesia and should be used in these patients if there is arterial hypoxemia despite a high FIO2.

Adult↗
PubMed2025

Admixture Mapping Reveals Evidence for Multiple Mitonuclear Incompatibilities in Swordtail Fish Hybrids.

How barriers to gene flow arise between closely related species is one of the oldest questions in evolutionary biology. Classic models in evolutionary biology predict that negative epistatic interactions between variants in the genomes of diverged lineages, known as hybrid incompatibilities, will reduce viability or fertility in hybrids. The genetic architecture of these interactions and the evolutionary paths through which they arise have profound implications for the efficacy of hybrid incompatibilities as barriers to gene flow between species. While these questions have been studied using theoretical approaches for several decades, only recently has it become possible to genetically map larger numbers of hybrid incompatibilities. Here, we use admixture mapping in natural hybrid populations of swordtail fish (Xiphophorus) to identify hybrid incompatibilities involving genetic interactions between the mitochondrial and nuclear genomes. We find that at least nine regions of the genome are involved in mitonuclear incompatibilities. These incompatibilities involve interactions between the nuclear genome and the X. malinche mitochondria, the X. birchmanni mitochondria, or both. Moreover, they vary in the strength of selection they experience and the degree to which they limit gene flow in natural hybrid populations. Our results build a deeper understanding of the complex architecture of selection against incompatibilities in naturally hybridising species and highlight an important role of mitonuclear interactions in the evolution of reproductive barriers between closely related species.

Animals↗
PubMedDate not supplied

Change in pulmonary venous admixture with varying inspired oxygen.

Pulmonary venous admixture (Qsp/Qt) was analyzed as a function of fractional concentration of inspired O2 (FIO2) in 30 patients who required postoperative mechanical ventilation. Pulmonary and radial artery blood-gas tensions and pH were measured and Qsp/Qt was calculated with FIO2 ranging from 0.21 to 1. In all patients, Qsp/Qt decreased when FIO2 was increased from 0.21 to 0.4 and then stabilized to an FIO2 of approximately 0.6. As the FIO2 was increased to 1, Qsp/Qt increased. Since the inhalation of gas mixture with FIO2 greater than or equal to 0.6 increased right-to-left intrapulmonary shunting of blood, we recommend respiratory function be evaluated during inhalation of a clinically useful concentration of O2 rather than at an FIO2 of 1.

Humans↗
PubMed1975

Recommended methods for compounding intravenous admixtures in hospitals.

Recommendations regarding (1)hospital receipt and storage of large-volume parenterals and (2)hospital compounding of intravenous admixtures are presented. The recommendations are presented in a stepwise manner, and a self-evaluation form is included. Also included is a pictorial illustration of a suggested dressing change for an i.v.catheter.

Drug Compounding↗
PubMed1975

Pharmacy-nursing communications in an intravenous admixture program.

A centralized pharmacy admixture program is discussed, with emphasis on the forms used to communicate between pharmacists and nurses. Aspects of the programs described include the patient intravenous profile folder, preparation and delivery of i.v. solutions, preparation of piggyback solutions and prefilled syringes of reconstituted antibiotics, and emergency intravenous solution stock.

Communication↗
PubMed1976

[Purification of antibiotic solutions of finely dispersed admixtures].

A possibility of complete separation of fine disperse admixtures from antibiotic fermentation broth filtrates by filtration with the use of special additives was shown. The purity of the filtrates and filtration rate depended on the procedure of addition, amount and average size of the particles of the filtration material.

Anti-Bacterial Agents↗
PubMed1978

Physicochemical determinants of incompatibility and instability in injectable drug solutions and admixtures.

Several physicochemical conditions or phenomena most commonly causing incompatibility, instability or related difficulties in parenteral drug solutions and admixtures are reviewed. The following factors involved in chemical incompatibilities are reviewed: concentration, pH, acid-base character, reduction-oxidation, photolysis, epimerization, temperature, dextrose catalysis and hydrolysis. The following factors involved in visual incompatibilities are discussed: pH, acid-base character, solvent system, color change, complexation, adsorption and adherence, dissolution rate, salting-out and leaching, and foaming. Pharmacists may recognize, predict and avoid parenteral imcompatibilities based on their experience, an understanding of physicochemical principles and reference to pertinent publications.

Chemical Phenomena↗
PubMed1979

Reference aids for developing policies and procedures for intravenous admixture services.

A table of literature citations designed to help hospital pharmacists develop a policy and procedure manual for i.v. admixture services is presented. The table is categorized according to literature that will aid in developing policies and procedures for specific aspects of admixutre services (e.g., distribution procedures, quality assurance). The citations were selected from two periodicals (American Journal of Hospital Pharmacy and Drug Intelligence & Clinical Pharmacy) and three other publications.

Bibliographies as Topic↗
PubMedDate not supplied

[Admixtures of antibiotic substances in enzyme preparations of microbial origin intended for use as food additives].

A group of enzymtic preparations, mainly of the Soviet make were investigated for the presence of antibiotic substances admixtures. Altogether 25 preparations obtained from molds, actinomycetes, bacteria and yeast were studied. The results showed that 18 preparations contained antibiotic substances in an amount of 0.6-1300 U, equivalent to oxytetracycline units per 1 g. Most often antibiotics were present in preparations of the pectinase and protease group. In the group of glucoamylase the antibiotic activity was uncovered in a single preparation. Procedures employed in determining the antibiotic activity of enzymatic preparations is described and the possible role of antibiotics in the manifestations of their toxic properties discussed.

Actinomycetales↗
PubMed1977

[Component composition and admixtures of related compounds in commercial preparations with an erythromycin base].

Chromatographic purity of erythromycin base preparations manufactured in the USSR with various technological procedures and those of 4 foreign firms was studied. All the preparations studied in addition to the main component of erythromycin A contained 5 to 7 per cent of erythromycin C and about 1.5 to 3.5 per cent of a non-identified component possessing a somewhat lower chromatographic mobility than erythromycin C. The admixture of 0.5--1 per cent of anhydroerythmycin was found in many erythromycin preparations. The preparations of some foreign firms contained also a number of additional substances. It was shown that the antimicrobial activity of anhydroerythromycin was 50-60 times lower than that of erythromycin. Direct correla;ion between the level of the antimicrobial activity of the market prepaetions of erythromycin and the level of its chemical purity was noted.

Animals↗
PubMed1975

Dermatoglyphics of Easter Islanders analyzed by pattern type, admixture effect, and ridge count variation.

The adult Easter Island population was fingerprinted in 1965 as part of an overall study of their human biology. Major findings of the dermatoglyphic analysis are as follows. Digit and bimanuar percentages of patterns (arches, loops, and whorls) were similar to those observed in Europeans. However, in terms of total pattern type distributions, the Islanders had many more whorls and a correspondingly much higher Pattern Intensity Index than those found in European groups. This difference was even present, although in lesser magnitude, in Easter Islanders known to be admixed with Europeans. Corresponding to a high occurrence of whorls, Mean Total Ridge Count (TRC) was also notably high. An association between TRC as a measure of pattern size and incidence of patterns was clearly evident in several groups available for comparison.

Dermatoglyphics↗
PubMed1975

G-6-PD polymorphism and racial admixture in the Cuban population.

The frequencies of the Gd-A, Gd-A- and Gd-B alleles have been estimated in a random sample of 455 female and 405 male high school students from Habana. The estimates of the Negro and Caucasian relative contributions to the present genetic make-up of the Habana population, based on these gene frequencies, are 0.20 and 0.80 respectively.

ABO Blood-Group System↗