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Biomedical subjects

E Jacobsen

Publications and source records attributed to E Jacobsen.

At least 19 recordsLinked to original sources
PubMed1992

Cloning, partial sequencing and expression of a cDNA coding for branching enzyme in cassava.

Branching enzyme is involved in the synthesis of amylopectin in plant reserve starch. A cDNA coding for cassava (Manihot esculenta Crantz) branching enzyme was cloned from a lambda gt11 cDNA library using a potato cDNA probe. The cloned cDNA was partially sequenced. The sequence data confirmed the identity of the clone when compared to that of potato, the homology being ca. 80% at the nucleotide level and 85% at the amino acid level. Furthermore, the cloned cassava cDNA was able to restore branching enzyme activity in a branching enzyme deficient Escherichia coli mutant. Results of the Southern analysis suggested that there is a single gene for this particular branching enzyme in the cassava genome. Study of expression patterns by northern hybridization showed that the gene is highly expressed in tubers. The transcript is detectable in stem and petiole, but not in leaves. In roots, the mRNA is hardly present. The expression levels at different stages of tuber growth are similar with exception of very young tubers in which it is relatively low. It is also shown that there is a difference in the level of branching enzyme expression between different cassava genotypes.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1992

Recurrent nerve/ansa cervicalis nerve anastomosis: a treatment alternative in unilateral recurrent nerve paralysis.

Sectioning of the right recurrent nerve was done in 5 mongrel dogs under general anaesthesia. The distal stump was anastomosed with the ansa cervicalis nerve branch to the sternothyroid muscle. Three to 5 months later the vocal cord movements during light and very light anaesthesia were videorecorded. Under light anaesthesia contraction and medial bulging of the reinnervated right vocal cord occurred in 4 of the dogs. Under very light anaesthesia there was also some adduction of the right vocal cord in these 4 dogs. The right recurrent nerve was then sectioned proximally to the anastomosis and stimulated electrically. In all 5 dogs we observed that electrical stimulation produced a strong adduction of the right vocal cord. Histochemistry of the right vocal and posterior cricoarytenoid muscles showed that reinnervation had taken place. The study indicates that in cases of unilateral vocal cord paralysis an anastomosis between the ansa cervalalis and the recurrent nerve will result in improved phonatory function of the affected vocal cord.

Anastomosis, Surgical↗
PubMed1991

[Treatment of purulent meningitis].

The principles for the management of bacterial meningitis in the State University Hospital are presented. The combination of ceftriaxone and ampicillin was chosen for initial, empirical therapy.

Ampicillin↗
PubMed1991

[Diagnosis of Pneumocystis carinii pneumonia in HIV-positive patients. The diagnostic value of induced sputum and exercise test].

The object of investigation is to illustrate the values of two noninvasive procedures: the induced sputum test and the exercise test in the diagnosis of Pneumocystis carinii pneumonia (PCP). Both of the procedures are described. Fifty HIV-positive men in whom interstitial pneumonia was suspected participated. PCP was diagnosed in 16 patients, in ten of these by the induced sputum test, the sensitivity of which is, therefore, 35-85% (95% confidence limits). The exercise test, an investigation for demonstration of exercise induced oxygen desaturation, was of good predictive value. Thus, seven out of nine patients with positive exercise test results had PCP as compared with two out of 19 with normal exercise test results, p = 0.0009. The sensitivity was thus 40-97%. In five out of the six patients with false negative results to the induced sputum test, the exercise test was performed and was positive in all of the case. The method is rapid and simple and merely requires access to an exercycle and a pulse-oxymeter preferably with a recorder. It is concluded that the exercise test and the induced sputum test are valuable investigations which supplement one another in cases of suspected PCP and which avoid the need for bronchoscopy in 53-80% of the patients.

Evaluation Studies as Topic↗
PubMed1991

[Risk and hemodynamic instability in spinal anesthesia].

We investigated 131 consecutive patients who were submitted to orthopaedic surgical interventions under spinal anaesthesia during a period of 12 months. Prior to operation, all of the patients were classified according to the Boston Cardiac Risk Index. Immediately before operation, approximately 500 ml sodium chloride solution was infused. Patients were registered as haemodynamically unstable when a peroperative fall in the mean arterial pressure of more than 30% occurred or when the systolic blood pressure fell to less than 80 mmHg. In 40 patients, haemodynamically unstable conditions developed peroperatively while 91 were haemodynamically stable. In Boston group III, 67% of the patients were haemodynamically unstable peroperatively which was significantly more than in the Boston group I (25%) and the Boston group II (32%) (p less than 0.005). The postoperative mortality was significantly higher (13%) among the total number of peroperatively haemodynamically unstable patients than among the peroperatively stable patients (3%) (p less than 0.05). In Boston group III, the postoperative mortality was 42% as compared with 1% and 7% in the Boston groups I and II, respectively (p less than 0.05). It is concluded that the risk of fall in blood pressure during spinal anaesthesia may be predicted by the Boston Cardiac Risk Index and that patients who develop haemodynamic instability during spinal anaesthesia have an increased risk of developing complications. These patients should be offered maximal postoperative observation and care.

Adult↗
PubMed1991

Expression of a chimaeric granule-bound starch synthase-GUS gene in transgenic potato plants.

Granule-bound starch synthase is the key enzyme in amylose synthesis. The regulation of this gene was investigated using a chimaeric gene consisting of a 0.8 kb 5' upstream sequence of the granule-bound starch synthase gene from potato and the beta-glucuronidase gene which was introduced into potato using an Agrobacterium tumefaciens binary vector system. The chimaeric gene was highly expressed in stolons and tubers, whereas the expression in leaves, stems or roots from greenhouse-grown plants was relatively low. However, leaves from in vitro grown plantlets exhibited an elevated GUS expression. The expression of the chimaeric gene was inducible in leaves by growth on relatively high concentrations of sucrose, fructose and glucose and was about 30- to 50-fold higher than in leaves from greenhouse-grown plants. The granule-bound starch synthase gene is expressed organ-specifically since stolons and tubers showed GUS activities 125- to 3350-fold higher than in leaves. The activities in these two organs are 3- to 25-fold higher than the expression of the CaMV-GUS gene. Histochemical analysis of different tissues showed that only certain regions of leaves and roots express high GUS activities. Stolons and tubers show high expression.

Agrobacterium tumefaciens↗
PubMed1991

Inhibition of the expression of the gene for granule-bound starch synthase in potato by antisense constructs.

Granule-bound starch synthase [GBSS; EC 24.1.21] determines the presence of amylose in reserve starches. Potato plants were transformed to produce antisense RNA from a gene construct containing a full-length granule-bound starch synthase cDNA in reverse orientation, fused between the cauliflower mosaic virus 35S promoter and the nopaline synthase terminator. The construct was integrated into the potato genome by Agrobacterium rhizogenes-mediated transformation. Inhibition of GBSS activity in potato tuber starch was found to vary from 70% to 100%. In those cases where total suppression of GBSS activity was found both GBSS protein and amylose were absent, giving rise to tubers containing amylose-free starch. The variable response of the transformed plants indicates that position effects on the integrated sequences might be important. The results clearly demonstrate that in tubers of potato plants which constitutively synthesize antisense RNA the starch composition is altered.

Amylose↗
PubMed1991

Sequence of the structural gene for granule-bound starch synthase of potato (Solanum tuberosum L.) and evidence for a single point deletion in the amf allele.

The genomic sequence of the potato gene for starch granule-bound starch synthase (GBSS; "waxy protein") has been determined for the wild-type allele of a monoploid genotype from which an amylose-free (amf) mutant was derived, and for the mutant part of the amf allele. Comparison of the wild-type sequence with a cDNA sequence from the literature and a newly isolated cDNA revealed the presence of 13 introns, the first of which is located in the untranslated leader. The promoter contains a G-box-like sequence. The deduced amino acid sequence of the precursor of GBSS shows a high degree of identity with monocot waxy protein sequences in the region corresponding to the mature form of the enzyme. The transit peptide of 77 amino acids, required for routing of the precursor to the plastids, shows much less identity with the transit peptides of the other waxy preproteins, but resembles the hydropathic distributions of these peptides. Alignment of the amino acid sequences of the four mature starch synthases with the Escherichia coli glgA gene product revealed the presence of at least three conserved boxes; there is no homology with previously proposed starch-binding domains of other enzymes involved in starch metabolism. We report the use of chimeric constructs with wild-type and amf sequences to localize, via complementation experiments, the region of the amf allele in which the mutation resides. Direct sequencing of polymerase chain reaction products confirmed that the amf mutation is a deletion of a single AT basepair in the region coding for the transit peptide.(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles↗
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↗
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↗