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Biomedical subjects

E Jacobsen

Publications and source records attributed to E Jacobsen.

At least 73 records · Page 4Linked to original sources
PubMed1994

Segregation analysis and RFLP mapping of the R1 and R3 alleles conferring race-specific resistance to Phytophthora infestans in progeny of dihaploid potato parents.

Phytophthora infestans (Mont.) de Bary is the most important fungal pathogen of the potato (Solanum tuberosum). The introduction of major genes for resistance from the wild species S. demissum into potato cultivars is the earliest example of breeding for resistance using wild germplasm in this crop. Eleven resistance alleles (R genes) are known, differing in the recognition of corresponding avirulence alleles of the fungus. The number of R loci, their positions on the genetic map and the allelic relationships between different R variants are not known, except that the R1 locus has been mapped to potato chromosome V. The objective of this work was the further genetic analysis of different R alleles in potato. Tetraploid potato cultivars carrying R alleles were reduced to the diploid level by inducing haploid parthenogenetic development of 2n female gametes. Of the 157 isolated primary dihaploids, 7 set seeds and carried the resistance alleles R1, R3 and R10 either individually or in combinations. Independent segregation of the dominant R1 and R3 alleles was demonstrated in two F1 populations of crosses among a dihaploid clone carrying R1 plus R3 and susceptible pollinators. Distorted segregation in favour of susceptibility was found for the R3 allele in 15 of 18 F1 populations analysed, whereas the R1 allele segregated with a 1:1 ratio as expected in five F1 populations. The mode of inheritance of the R10 allele could not be deduced as only very few F1 hybrids bearing R10 were obtained. Linkage analysis in two F1 populations between R1, R3 and RFLP markers of known position on the potato RFLP maps confirmed the position of the R1 locus on chromosome V and localized the second locus, R3, to a distal position on chromosome XI.

Alleles↗
PubMed1994

Multiple alleles for tuber shape in diploid potato detected by qualitative and quantitative genetic analysis using RFLPs.

Tuber shape in potato is commonly regarded as displaying continuous variation, yet at the diploid level phenotypes can be discerned visually, having round or long tubers. Inheritance of qualitative tuber shape can be explained by a single locus Ro, round being dominant to long. With restriction fragment length polymorphisms (RFLPs) the Ro locus was mapped on chromosome 10. Tuber shape was also studied as a quantitative trait, using the length/width ratio as trait value. The estimated broad sense heritability was h2 = 0.80. The morphologically mapped Ro locus explained 75% of the genetic variation, indicating the presence of a major quantitative trait locus (QTL) at the Ro locus and minor genetic factors. RFLP alleles linked with Ro alleles were used to divide the progeny into four genotypic classes: RofemaleRomale:Rofemalero:roRomale:roro = 1:1:1:1. The recessive ro allele is identical by descent in both parents. The significantly different effects (P = 0.0157) of the non-identical alleles Rofemale and Romale provided evidence for multiallelism at the Ro locus. Linkage mapping of the Ro locus was compared with QTL mapping. Only those markers which are polymorphic in both parents allow accurate QTL mapping when genetic factors segregate from both parents. This finding applies to QTL mapping in all outbreeders without homozygous inbred strains.

Alleles↗
PubMed1994

Posttraumatic osteolysis of the pubic bone simulating malignancy.

Posttraumatic osteolysis (PO) of the os pubis is a diagnostic entity characterized at radiography by rapidly progressing destructive changes in fractures of the pubic body or rami. Fourteen patients with PO are here reported of whom in 8 the radiographic course of the condition was followed. They were all post-menopausal women and 7 were predisposed to osteopenia. The primary fractures were related to mild trauma in 7 patients and 7 had insufficiency fractures. Four patients had bilateral symmetrical PO. All 14 patients had concomitant insufficiency fractures of the sacrum observed at radiography, CT, scintigraphy or MR, probably due to pelvic instability caused by the PO of the os pubis. Symptoms of the sacral fractures usually dominated the clinical condition. Bony healing of the PO did not occur in any of the patients, but in all 8 patients followed radiographically, the fractures of the sacrum healed clinically and at CT. Knowledge about the condition is important to avoid unnecessary biopsy of the PO considered a metastatic lesion and/or extensive diagnostic search for a primary tumor.

Aged↗
PubMed1993

[Pulse oximetry and obstructive sleep apnea].

We report a case of a 54 years old man, treated with Methylphenidate (Ritalin) because of narcolepsy, who was referred with suspected vertebro-basilar insufficiency. In the hospital, apnoea during sleep attacks were observed. A polysomnography showed marked obstructive sleep apnoea with a disturbed hypnogram, but during the apnoeas the oxygen saturation only decreased by three to six percent. If a patient suspected for obstructive sleep apnoea has only small desaturations, an oximetry can be insensitive as the only "sleep examination", and a full polysomnography is recommended.

Humans↗
PubMed1993

Salen-manganese complexes are superoxide dismutase-mimics.

Complexes of manganese have previously been shown to exhibit SOD activity. In this study, we tested the ability of several (salen)-manganese complexes to scavenge O2.. Both neutral and cationic complexes were determined to be SOD-mimics. The activity of the complexes was not affected by the presence of bovine serum albumin in the assay. For most compounds, the activity was inhibited by the addition of EDTA. The stability and high catalytic activity of some of these molecules suggest that they might have potential use in a variety of conditions which involve overproduction of oxygen free radicals.

Edetic Acid↗
PubMed1993

[Complications of spinal anesthesia compared to general anesthesia. A prospective study of 408 consecutive orthopedic patients].

UNLABELLED: In this prospective study the preoperative risk classification and pulmonary status was compared to postoperative mortality and morbidity, following either spinal or general anaesthesia. We studied 408 consecutive orthopaedic patients. Comparing the anaesthetic methods we found no differences in mortality or in frequency of cardiac complications, while the non-cardiac complications were seen more frequently in patients who had undergone spinal anaesthesia (p < 0.05). Patients from the lower risk groups with a preoperative abnormal pulmonary status had a higher frequency of postoperative pulmonary complications following spinal anaesthesia than following general anaesthesia (p = 0.015). IN CONCLUSION: 1) We find no difference in postoperative mortality depending on the anaesthetic method chosen, 2) the predictive value of the Boston Cardiac Risk index is identical for the two anaesthetic methods, and 3) the anaesthetic method of choice for the pulmonary disabled patient has not yet been established.

Adult↗
PubMed1993

[Respiratory monitoring during sleep].

A review of respiratory disorders of sleep with the possible related clinical alterations are described. Techniques and methods used in non-invasive respiratory monitoring during sleep are presented. Diagnostic events and therapeutic approaches are discussed related to special patient groups: the obstructive sleep apnoea syndrome, asthma, chronic obstructive pulmonary disease and neuromuscular diseases.

Female↗
PubMed1993

Isolation and characterization of a cDNA encoding granule-bound starch synthase in cassava (Manihot esculenta Crantz) and its antisense expression in potato.

A tuber-specific cDNA library of cassava (Manihot esculenta Crantz) was constructed and a full-length cDNA for granule-bound starch synthase (GBSS, also known as waxy protein), the enzyme responsible for the synthesis of amylose in reserve starch, was cloned. Sequencing of the cloned cDNA showed that it has 74% identity with potato GBSS and 60-72% identity with GBSS from other plant species. The cDNA encodes a 608 amino acid protein of which 78 amino acids form a chloroplast/amyloplast transit peptide of 8.37 kDa. The mature protein has a predicted molecular mass of 58.61 kDa (530 amino acids). Comparison of the GBSS proteins of various plant species and glycogen synthase of bacteria showed extensive identity among the mature form of plant GBSS proteins, in which the monocots and dicots form two separate branches in the evolutionary tree. From analysis of the genomic DNA of allotetraploid cassava, it is shown that GBSS is a low-copy-number gene. GBSS transcript is synthesized in a number of different organs, but most abundantly in tubers. Potato plants were transformed with the cassava GBSS cDNA in antisense orientation fused between the potato GBSS promoter and the nopaline synthase terminator. The expression of the endogenous GBSS gene in these transgenic potato plants was partially or completely inhibited. Complete inhibition of GBSS activity by the cassava antisense gene resulted in absence of GBSS protein and amylose giving rise to almost complete amylose-free potato starch. This shows that also heterologous genes can be used to achieve antisense effects in other plant species.

Base Sequence↗
PubMed1993

Ventilation in ARDS and asthma: the optimal blood gas values.

Artificial ventilation of patients with acute respiratory diseases, i.e. ARDS and severe asthma, may involve the risk of pulmonary oxygen toxicity as well as volutrauma. The relationship between ventilator treatment and volutrauma suggests that only in patients with normal lungs the aim of ventilator treatment should be an arterial carbon dioxide tension and pH within the normal ranges. In patients suffering from a lung disease the clinical target must be based not only upon the arterial blood gases but also upon airway pressure and respiratory tidal volume. Thus during artificial ventilation of a patient with an acute pulmonary disease the following arterial pH and pCO2 optima are proposed: pH 7.35, with a range from 7.1 to 7.4; pCO2 is related to pH but an acceptable range is 5-12 kPa. The lowest acceptable fraction of inspired oxygen and thereby the safe lower level of arterial pO2 for an individual patient depends on many factors. The lower limit may be about 3 kPa, but the arterial pO2 should not be evaluated as an isolated parameter. It is related to the general oxygen transport capability of arterial blood, extractable oxygen, cardiac output and the microcirculation.

Asthma↗
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↗