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Biomedical subjects

E Turner

Publications and source records attributed to E Turner.

At least 55 records · Page 3Linked to original sources
PubMed1987

Two hundred out-patient laparoscopic clip sterilizations using local anaesthesia.

Female sterilization using clips applied laparoscopically under local anaesthesia was used in 200 women. Apart from two patients in whom there were technical difficulties, the operation was completed without complication and without immediate or delayed morbidity. The technique, which avoids the risks of general anaesthesia, is commended as a safe, simple method of sterilization suitable for, and acceptable to, the majority of women.

Adult↗
PubMed1986

Ovothiol: a novel thiohistidine compound from sea urchin eggs that confers NAD(P)H-O2 oxidoreductase activity on ovoperoxidase.

Sea urchin eggs contain a small molecular weight heat-stable factor that confers cyanide-resistant NAD(P)H-O2 oxidoreductase activity on ovoperoxidase (Turner, E., Somers, C. E., and Shapiro, B. M. (1985) J. Biol. Chem. 260, 13163-13171), the enzyme responsible for cross-linking the extracellular protein coat (fertilization membrane) of the egg. Here we report the isolation of the active cofactor and its identification by ultraviolet, NMR, and mass spectroscopy as a new sulfur-containing amino acid derivative, 1-methyl-alpha N,alpha N-dimethyl-4-thiohistidine, or ovothiol. Ovothiol reacts slowly with atmospheric oxygen or rapidly with micromolar concentrations of H2O2 to form ovothiol disulfide, which is inactive as a cofactor for the ovoperoxidase NAD(P)H oxidase. Reduced active ovothiol is regenerated by treatment with disulfide reductants and shows significant differences in its ultraviolet and NMR spectra from oxidized ovothiol. The oxidoreductase activity of the ovoperoxidase/ovothiol system is similar to that previously characterized with crude cofactor preparations; it is greatly enhanced by Mn2+ and is relatively insensitive to CN-, compared to the peroxidase activity of ovoperoxidase. The ovothiol content of eggs is estimated as 1.8 pmol/egg or an intracellular concentration of 6.8 mM. This concentration exceeds the amount of reductant needed for the CN-(-)insensitive oxygen consumption following fertilization and used in the production of H2O2 for fertilization membrane cross-linking. Whether ovothiol is involved in the cross-linking reaction, protects the egg from damage from H2O2, or has another role in development remains unclear.

Amino Acids, Sulfur↗
PubMed1986

[Fenoterol (Partusisten)-associated lung edema. A case report].

The side effects of a beta 2-mimetic tocolytic therapy are of importance for anaesthesiologists who administer anaesthesia for obstetric operations, as our case report illustrates. In a healthy 28 year old pregnant woman during the 32nd week of pregnancy i.v. fenoterol was started because of premature labor. After two days severe respiratory failure developed and cesarean section was performed. The patient needed mechanical ventilation with positive endexpiratory pressure and high inspiratory oxygen concentrations (F1O2 greater than 0.7) for 5 days thereafter. The chest x-ray revealed a fluid lung. With artificial respiration and a consequent diuretic therapy with dopamine and furosemide (10 mg . h-1 continuously, negative water balance--5,000 ml on the 4th day) gas exchange improved and extubation was possible on the 6th postoperative day. After exclusion of cardiac or renal disease as well as aspiration of gastric content, the diagnosis of a fenoterol-associated pulmonary edema was thought probable. From the literature it is known that beta 2-mimetics can aggravate the increased water and sodium retention during pregnancy and cause pulmonary edema by an additional increase in pulmonary artery pressure. Therapy consists of adequate oxygenation and induction of diuresis with continuous furosemide and dopamine to achieve negative water balance. When administering anaesthesia to patients on tocolytic therapy positive water balance has to be avoided and great care must be directed to the postoperative gas exchange.

Adult↗
PubMed1985

The relationship between a novel NAD(P)H oxidase activity of ovoperoxidase and the CN- -resistant respiratory burst that follows fertilization of sea urchin eggs.

The extracellular protein coat of the sea urchin egg is cross-linked after fertilization via dityrosyl linkages made by an exocytosed ovoperoxidase. The source of oxidant for this reaction is unknown, but eggs produce H2O2 in amounts equivalent to the cyanide-insensitive O2 uptake "respiratory burst" that follows fertilization. Several possible H2O2-forming oxidase activities, including glucose, xanthine, fatty acyl, and fatty-acyl CoA oxidases, were absent from the egg cortex. However, an NAD(P)H-O2 oxidoreductase activity was found in the egg cortex and was completely accounted for by ovoperoxidase. Homogeneous ovoperoxidase exhibits two types of NAD(P)H oxidase activity. One of these activities is similar to that of horseradish peroxidase and lactoperoxidase; it is dependent on Mn2+ ions and catalytic amounts of phenols, such as 2,4-dichlorophenol and N-acetyltyrosinamide, and is greater than 95% inhibited by 0.1 mM cyanide. A second, novel oxidase activity utilizes Ca2+ and an unidentified, heat-stable, Mr less than 1000 factor that can be extracted by ethanol from egg homogenates. This NADH oxidase activity is only 40% inhibited by 0.1 mM cyanide and is maximally stimulated by 10 mM Ca2+. It has an apparent Km for NADH of 50 microM. The stoichiometry of NADH:O2 consumption is 1.6:1, but approaches 2:1 in the presence of 20 micrograms/ml superoxide dismutase or 200 micrograms/ml catalase. This indicates that complete reduction of O2 to water occurs and that the reaction does not produce H2O2 stoichiometrically. However, nearly complete inhibition of the reaction by higher catalase concentrations suggests that H2O2 is an intermediate. The properties of this novel oxidase activity suggest that it may play such a role in vivo.

Animals↗
PubMed1984

Metabolic and hemodynamic response to hyperventilation in patients with head injuries.

The effects of controlled moderate hyperventilation (paCo2 approximately 31 mmHg) on cardiovascular parameters and whole-body-oxygen-uptake (VO2) was studied in 10 patients with head injuries, who were unconscious and artificially ventilated at the time of the investigation. VO2 was measured with the Beckmann Metabolic Measurement Cart and also calculated from cardiac output and arterio-mixed venous oxygen content difference. A mean increase in VO2 (+ 19.6% of control) was observed after 2 h of hyperventilation. Cardiac output remained unchanged. This resulted in a decrease of venous oxygen content and impaired full oxygenation of the blood. Our results indicate that hyperventilation should not be a routine procedure. Close monitoring of arterial and venous blood gases is recommended, when hyperventilation is applied.

Adult↗
PubMed1984

[Rewarming from moderate to deep hypothermia: plasma catecholamine content, metabolism and circulatory function. 2 case reports].

Two patients were rewarmed from hypothermia (esophageal temperature 27.2 degrees C, 27.5 degrees C respectively). The first case suffered from head-injury after alcohol ingestion and was deeply comatose. A metabolic or cardiovascular regulatory response to cold was not observed in this patient. The relationship between esophageal temperature and whole-body-oxygen consumption was quantified with a Q10 of 2.75 during rewarming (27.2-37.2 degrees C). His epinephrine levels were greatly elevated to 1,000 pg/ml whereas norepinephrine levels were only moderately increased to 250 pg/ml. Premature ventricular contractions (PVCs) during intubation or from the pulmonary artery catheter were not observed. The second patient was a 87 year old man with accidental hypothermia. He exhibited shivering at an esophageal temperature of 27.5 degrees C which indicated persistent thermoregulation. In contrast to the first case his norepinephrine levels were elevated to 1,500 pg/ml and his epinephrine levels only to 450 pg/ml. After onset of surface rewarming an additional increase in norepinephrine levels was observed and an increasing rate of PVC's (15/min) recorded, which ceased when temperature returned to normal. Our observations indicate that part of the cardiac complications during rewarming from deep hypothermia may result from thermoregulation and additional catecholamine liberation.

Adult↗
PubMed1984

[Intraoperative mechanical autotransfusion: studies on preserved blood for retransfusion].

The blood loss by 10 patients who underwent major thoracic or abdominal vascular surgery was saved with the Bentley Autotransfusion System ATS 2000. The blood was examined for several parameters. Disadvantages of the saved blood were: low haematocrit, high levels of free plasma haemoglobin, the size of fat particles, a shift to the left of the oxyhaemoglobin saturation curve and severe alteration of coagulation parameters. The results indicate, that autotransfusion should be used with caution.

Blood Coagulation↗
PubMed1983

Current status of the molecular structure and function of the plasma sex steroid-binding protein (SBP).

Purification and characterization of the sex steroid-binding protein (SBP) from human, macaque, baboon, and rabbit sera indicate that the protein is composed of two polypeptide chains which associate noncovalently to yield a native structure having molecular weight distributions of about 88,000 for primate SBPs, and 80,000 for rabbit SBP. The subunit molecular weight distributions are 44,000 for human SBP, 47,000 for macaque and baboon SBP's, and 40,000 for rabbit SBP. Isoelectric focusing show extensive microheterogeneity for all four SBPs. The patterns appear to be unique for each species and reveal the presence of at least twelve bands of different colour intensity reflecting a specific spectrum of active SBP molecules. The existence of the large number of dimeric forms of SBP arises through the combination of many variants of the same two subunits containing different amounts and types of carbohydrate sidechains. Physiological studies on the intravenous infusion of pure rhesus SBP, human SBP, and purified monospecific SBP-antibodies into the rhesus reveal an inverse relationship between SBP and the metabolic clearance rate of testosterone. The effect is complex and depends on the concentration of SBP, albumin, and testosterone which in turn influences the distribution of testosterone between albumin and SBP.

Animals↗
PubMed1983

Is there an increased risk of Haemophilus influenzae septicemia in children with sickle cell anemia?

The risk of Haemophilus influenzae septicemia/meningitis to children who have sickle cell anemia (SS) has been determined to be greater than that seen among normal infants. Of ten bacteriologically proven cases, eight episodes of infection were observed among 234 children with sickle cell anemia (645 person-years), who were less than 5 years of age. There was one case per 69 infants with sickle cell anemia who were less than 18 months old and one case per 36 children with sickle cell anemia between 19 and 59 months of age. Unexpectedly, two infections occurred among 224 children (824 person-years), aged 5 to 9 years; both died. Contrary to the rapid clinical course of pneumococcal infections in children with sickle cell anemia H influenzae septicemia was regularly heralded by a greater than 24-hour prodrome of upper respiratory tract infection, low-grade fever, and otitis media. Three (30%) preventable deaths occurred. Antibiotic therapy for the febrile child with sickle cell anemia must be predicated on the known 400-fold increased risk of pneumococcal septicemia in those less than 5 years old and the fourfold risk of H influenzae septicemia in those less than 9 years of age.

Anemia, Sickle Cell↗
PubMed1982

Frequency of anaphylactoid reactions during intravenous urography with radiographic contrast media at two different temperatures.

One hundred randomly selected patients undergoing routine excretory urography were assigned in double-blind fashion by alternate entry pairs to receive radiographic contrast media at 37 degrees C (Group I) or room temperature (Group II). There were three anaphylactoid reactions and five nonanaphylactoid reactions in Group I, and five anaphylactoid and eight nonanaphylactoid reactions in Group II, differences that were not statistically significant. No differences were detected between reactors and nonreactors. Thus, in this study, infusion temperature had no effect on the frequency of adverse reactions to radiographic contrast media during excretory urography.

Adolescent↗
PubMed1982

[A method for the determination of O2-uptake and CO2-elimination from the respiratory gases in mechanically ventilated patients (author's transl)].

A method for the assessment of O2-uptake and CO2-elimination from respiratory gases in mechanically ventilated patients is presented, the Beckman metabolic measurement cart. It was designed for exercise measurements. In patients under respirator treatment, there are problems resulting from the pressure sensitivity of the polarographic O2-electrode. Correct measurements of O2-uptake is possible if an inspired O2-concentration of 50 per cent is not exceeded.

Anesthesia↗
PubMed1982

[Whole body oxygen uptake in coronary artery bypass surgery (author's transl)].

In 10 patients who underwent aorto-coronary bypass operations haemodynamic parameters and whole body oxygen uptake were monitored, beginning after induction of anaesthesia, during extracorporeal circulation and the postoperative period up to 5 h. In the intensive care unit a new device for the continuous measurement of whole body oxygen uptake from expired gases was used. For anaesthesia constant doses of fentanyl (10 micrograms/kg/h) and nitrous oxide were given. These were supplemented by low concentrations of halothane and nitroglycerine if hypertension occurred. Before extracorporeal circulation hypertensive states were observed in 8 cases and were effectively controlled without compromising tissue oxygenation. During extracorporeal circulation oxygen consumption was reduced more than could be explained only by the effects of hypothermia, indicating a limited shock state. Within the first postoperative hour the total peripheral resistance increased more than during the whole operation, impairing cardiac function at low levels of oxygen uptake. Thereafter a rise in metabolism was seen, partially induced by shivering which led to a marked (235% of control) increase in whole body oxygen uptake. This was accompanied by a reduction of the total peripheral resistance and an improvement of cardiac function. No acidosis was observed. Artificial ventilation is mandatory until metabolic demands have normalized. Noninvasive continuous monitoring of whole body oxygen uptake was useful for the assessment of cardiovascular function, increased postoperative metabolic demands, early detection of hypovolaemia and weaning from artificial ventilation.

Anesthesia↗
PubMed1981

The effect of alpha-thalassemia on the expression of the beta-thalassemia/HPFH heterozygote in a black family.

A 2-yr-old black girl presented with a thalassemic clinical picture and was found to have nearly 100% fetal hemoglobin in her red cells. Pedigree analysis indicated that she was a heterozygote for the hereditary persistence of fetal hemoglobin gene and for a beta O-thalassemia gene. A brother, who also had nearly 100% fetal hemoglobin in his red cells, manifested, in contrast to his sister, no anemia and only minimal splenomegaly. Examination of the family's alpha-globin loci using the restriction endonuclease Eco Rl demonstrated that the brother had a single alpha-locus deletion that he had inherited from his mother. The mild clinical manifestations of this boy are consistent with the often expressed view that excess alpha chains may contribute significantly to the hematologic manifestation of beta-thalassemia.

Black People↗