Search PubMed⌕ Search

Biomedical subjects

E Jacobsen

Publications and source records attributed to E Jacobsen.

At least 91 records · Page 5Linked to original sources
PubMed1990

[Diaphragm pacing by electric stimulation of the phrenic nerves].

Artificial ventilation by electric stimulation of the phrenic nerves has become clinically significant within the past 20 years and, in the world as a whole, approximately 700 patients have been treated with implanted diaphragmatic pacemakers. The two first patients in whom diaphragmatic pacemakers were implanted in Denmark, had sustained accidental fractures of the second cervical vertebra with subsequent high cervical spinal cord lesions with not only tetraplegia but also respiratory arrest. In both patients, diaphragmatic pacemakers were implanted bilaterally and these were employed for 12-14 hours daily while ventilation with a respirator was employed at night. The main indications for diaphragmatic pacing are paralysis of respiration following high cervical spinal traumata and the chronic central hypoventilation syndrome (sleep apnoea of Undine's curse). Diaphragmatic pacing may improve the mode of ventilation and the quality of life for patients with tetraplegia and respiratory insufficiency. On account of the potential technical problems, the risk of complications and the limited number of patients in whom this operation is suitable, implantation of diaphragmatic pacemakers should be concentrated in a few centres and probably only one in Denmark.

Adolescent↗
PubMed1990

Radiolabelling of platelets with technetium-99m.

A method for labelling of platelets with technetium-99m (Tc-99m) is presented. In principle, aminobenzoic acid and tartaric acid are used as reagents, allowing Tc-99m complexes of intermediate chemical stability to be formed. These complexes react rapidly with proteins, such as platelet proteins, when added. We have examined the isolation procedure for the platelets and the labelling procedure using residual aggregational ability and residual content of beta-thromboglobulin (beta-TG) as indicators of damage to the platelets. In its final version the method allowed a 32.6 +/- 2.7% (mean +/- SD) incorporation of Tc-99m into platelets which again showed a 66 +/- 15% residual aggregational ability, tested by 50 mumol/l of ADP, and a 79 +/- 17% residual content of beta-TG releasable by 10 IU/ml of thrombin. In a pilot clinical study involving 28 patients we found labelled autologous platelets useful in detecting lung embolism and deep vein thrombosis.

Adenosine Diphosphate↗
PubMed1990

Selective measurement of starch synthesizing enzymes in permeabilized potato tuber slices.

Osmotically permeabilized potato (Solanum tuberosum L.) tuber slices were used to study the biosynthesis of starch under semi in vivo conditions. Criteria to distinguish the various enzymes involved in starch biosynthesis were developed based on the characteristics of the enzymes in in vitro experiments. Branching enzyme activity was inhibited at pH 8.5 or higher, while the starch synthases functioned optimally between pH 8.8 and 9.1. Unprimed soluble starch synthase activity was only apparent in the presence of sodium citrate (0.4 molar or higher). Granulebound and primed soluble starch synthase were active in the absence of sodium citrate. Primed soluble starch synthase activity was susceptible to inhibition by 10 millimolar zinc sulfate, while granule-bound starch synthase activity was not. The incorporation of the Glc moiety of ADP-Glc into starch in tissue slices by the various starch synthases was consistent with in vitro data with respect to the affinity of the enzymes for substrate, the pH profile, the stimulation by citrate, and the inhibition by zinc sulfate. These data were used to determine the activity of each of the starch synthases in tissue slices: granule-bound and soluble starch synthase transferred 37 and 55 picomoles ADP-Glc per hour per milligram fresh weight into starch of permeabilized tissue slices at 30 degrees C and pH 9.1. In the presence of 0.5 molar sodium citrate, at least 40 picomoles ADP-Glc per hour per milligram fresh weight as transferred into starch by unprimed soluble starch synthase activity.

Journal Article↗
PubMed1989

[Complicated malaria].

An increasing number of cases of malaria, imported to Denmark, are caused by Plasmodium falciparum and severe and complicated cases are more often seen. In the Department of Infectious Diseases, Rigshospitalet, 23 out of 32 cases, hospitalized from 1.1-30.6.1988, i.e. 72%, were caused by P. falciparum; of these, seven (30%) were complicated, according to the definition by WHO. The importance of prompt diagnosis and treatment with intravenous quinine is stressed, and more recent supporting therapies including blood exchange transfusion are reviewed.

Blood Transfusion↗
PubMed1989

Interhospital comparisons of patient outcome from intensive care: importance of lead-time bias.

We studied 432 admissions to two Danish ICUs by using a standard severity of illness classification system to assess utilization and outcome. Substantial differences in utilization were found. The patients in Hospital 2 were younger, had better previous health records, and were admitted significantly more often for active treatment as opposed to monitoring than the patients in Hospital 1. Although their measured severity of illness was similar, patients at Hospital 2 received significantly more therapy and their mortality exceeded that of the patients at Hospital 1. The mortality rate of Hospital 2 also exceeded that predicted from a recent survey of U.S. hospitals. We found, however, that 35% of the patients at Hospital 2 had been transferred to the ICU from other ICUs. This created the possibility of an adverse selection and lead-time bias for the patients at Hospital 2. These findings indicate that although national and international comparisons of intensive care are now possible using common classification systems, this progress has created a new need for more precise measurement of potential confounding biases, such as the duration of intensive care services received before formal ICU admission.

Adult↗
PubMed1989

Cardiovascular function measured by ultrasound Doppler in healthy young men after ingestion of dextropropoxyphene napsylat.

In a double blind cross-over study 10 healthy male volunteers were given either 300 mg dextropropoxyphene napsylat (DP) or placebo daily for 16 days. The serum levels of DP and the metabolite nordextropropoxyphene were measured on day 3, 6 and 16. Haemodynamic measurements were made on day 1 and day 16, both at rest and during exercise. The measurements were made non-invasively, with a pulsed ultrasound Doppler. Blood pressure, heart rate, velocity, cardiac output, left cardiac work, increased during work, but showing no significant differences between the groups. The systolic time intervals were also measured by the ultrasound Doppler. The preejection period increased significantly in the DP-group, whereas the ratio preejection period/left ventricular ejection time which reflects the contractility of the heart did not differ significantly. It is concluded that DP taken daily in a normal dose for 16 days did not affect the heart function in healthy young men.

Adult↗
PubMed1987

Estimation of the determinants of transcutaneous oxygen tension using a dynamic computer model.

A dynamic model for oxygen transport within the outer layers of the skin and a tcPO2 sensor has been developed. By comparing model simulations with clinical measurements from adults, it is possible to analyze some of the physiologic and physical determinants of the tcPO2 measurement. The results indicate that the permeability of the epidermis is a significant parameter when using a microcathode sensor. Using this model, the values obtained for normalized stratum papillare blood flow and metabolic oxygen consumption of the dermis are higher than those seen for other models.

Adult↗
PubMed1987

Biochemical and genetic comparison of two nitrate reductase-deficient pea mutants disturbed in the cofactor.

Two nitrate reductase (NaR)-deficient mutants of pea (Pisum sativum L.), E1 and A300, both disturbed in the molybdenum cofactor function and isolated, respectively, from cv Rondo and cv Juneau, were tested for allelism and were compared in biochemical and growth characteristics. The F1 plants of the cross E1 X A300 possessed NaR and xanthine dehydrogenase (XDH) activities comparable to those of the wild types, indicating that these mutants belong to different complementation groups, representing two different loci. Therefore, mutant E1 represents, besides mutant A300 and the allelic mutants A317 and A334, a third locus governing NaR and is assigned the gene destignation nar 3. In comparison with the wild types, cytochrome c reductase activity was increased in both mutants. The mutants had different cytochrome c reductase distribution patterns, indicating that mutant A300 could be disturbed in the ability to dimerize NaR apoprotein monomers, and mutant E1 in the catalytic function of the molybdenum cofactor. In growth characteristics studied, A300 did not differ from the wild types, whereas fully grown leaves of mutant E1 became necrotic in soil and in liquid media containing nitrate.

Coenzymes↗
PubMed1987

Prediction of cardiac risk in non-cardiac surgery.

This prospective study was carried out to develop a model for the prediction of cardiac risk in non-cardiac surgery. Detailed data were collected concerning the preoperative status of 2609 consecutive patients, who were followed closely during the postoperative course. Fatal or life-threatening cardiac complications occurred in 68 patients (2.6%). By utilizing logistic regression, a model for prediction of cardiac risk was developed. The model contained six significant preoperative predictor variables: Congestive heart failure (with 3 degrees of severity); ischaemic heart disease (with 2 degrees of severity); diabetes mellitus; serum creatinine above 0.13 mmol l-1; emergency operation; and the type of operation (two categories). With this model it seems possible to discriminate between patients with very different levels of cardiac risk.

Adult↗
PubMed1986

The early history of psychotherapeutic drugs.

The four most frequently used groups of drugs in psychiatric therapy are: neuroleptics, antidepressants, anxiolytics, and lithium salts. Their introduction came largely during the past 3 decades. This review summarizes the history of the research that led to their discovery and to the present concept of their modes of action.

Animals↗
PubMed1986

Dissociation of renal and respiratory effects of acetazolamide in the critically ill.

The effects of acetazolamide on renal and erythrocyte carbonic anhydrase were studied in 12 critically ill patients. In the first part of the investigation (n = 6) we examined the renal effects of increasing doses of acetazolamide. The maximal renal excretion of water and bicarbonate was achieved with acetazolamide 2.5-5 mg kg-1 i.v. In the second part (n = 6), the associated respiratory effects of the effective renal dose of acetazolamide 5 mg kg-1 were evaluated. We found a statistically significant 4% decrease in pulmonary carbon dioxide excretion in the 10-min sampling period immediately following the administration of acetazolamide, but thereafter carbon dioxide elimination proceeded at a normal rate. The observed carbon dioxide retention is clinically unimportant, and we recommend acetazolamide as an effective means of eliminating surplus water and bicarbonate in the critically ill.

Acetazolamide↗
PubMed1986

Halothane hepatitis in a prospective study of postoperative complications.

In a prospective study comprising 2609 consecutive surgical patients, of whom 1166 were anesthetized with halothane, four cases of hepatitis were encountered. The incidence of hepatitis among those who received halothane was 1:292 in our material. The high incidence may be explained by the recognition of milder forms of hepatitis and by the selection of the series (over 40 years). Serum alanine aminotransferase should be investigated in all patients with postoperative pyrexia of unknown origin if mild forms of halothane hepatitis are to be discovered. The patient's history should be carefully examined for previous postoperative pyrexia of unknown origin following halothane anesthesia, in which case other anesthetics should be chosen.

Aged↗
PubMed1985

Oxygen uptake and carbon dioxide elimination after acetazolamide in the critically ill.

Acetazolamide, which reversibly inhibits carbonic anhydrase, is a useful diuretic in alkalotic and over-hydrated patients. In two earlier investigations we have consistently found increases in the arterial and venous oxygen saturation and tension when patients were treated with acetazolamide 15 mg . kg-1. A plausible explanation of this phenomenon is that acetazolamide diminishes oxygen consumption. In the present study we measured oxygen uptake in 10 critically ill patients. We found a minor and statistically insignificant decrease in oxygen consumption. Nevertheless SVO2 increased from 0.77 to 0.83 and PVO2 from 5.9 kPa to 6.8 kPa. It is still not possible from this investigation to determine the origin of the improvement in blood oxygenation. The inhibition of carbonic anhydrase caused a CO2 retention of 5.8% of the total CO2 production. An increase in body stores of CO2 of this magnitude is without clinical significance.

Acetazolamide↗