Search PubMed⌕ Search

Biomedical subjects

H Nielsen

Publications and source records attributed to H Nielsen.

At least 217 records · Page 12Linked to original sources
PubMed1990

[Prehospital treatment. The Odense ambulance project. A prospective study].

No legislation exists about ambulance services in Denmark. The present Danish prehospital treatment is undertaken by Falcks Redningskorps A/S and the municipal fire services. During a period of 12 months (1.2.1988-31.1.1989) a prospective investigation was carried out in Odense concerning the effect of medical support to the ambulance service, partly in the form of a medically staffed ambulance, partly in the form of an arrangement in which an independent doctor's car (rendez-vous arrangement) was sent together with the nearest ambulance. In addition, the heart ambulance model as recommended by the Danish National Board of Health was also tested. Experience from abroad and recent Danish trial arrangements demonstrate the positive effect of extended professional prehospital treatment. The authors consider, therefore, that an ambulance law is required as this would ensure better and more uniform prehospital treatment in Denmark. Planning of the future prehospital treatment of acute and injured patients including the extent of the training, equipment and treatment must be established on the basis of a healtheconomical assessment of the Danish arrangements.

Ambulances↗
PubMed1990

[Out-of-hospital heart arrest. Prospective study of various types of expanded prehospital treatment in Odense].

During the period 1.2.1988-31.1.1989, a prospective investigation was undertaken of the intensive prehospital treatment in Odense. Comparison was undertaken between a medically staffed ambulance (2 months), a motorized doctor (rendez-vous, model 4 months) and the heart ambulance (recommended by the Danish National Board of Health (6 months]. Out of 28 patients brought in by the medically staffed ambulance, two (7%) were discharged alive. Out of 57 patients brought in the phase with the motorized doctor nine (16%) were discharged alive. Out of 78 patients brought in by heart ambulance one (1%) was discharged alive. The results of this investigation reveal that the prehospital treatment of cardiac arrest in Odense can be improved by participation of a doctor in the treatment, (particularly the rendezvous model). Suggested improvements consist of 1) improved alarm system, 2) intensification of training laymen in treatment of cardiac arrest and 3) increased information to the population.

Ambulances↗
PubMed1990

The divergence in the excitation-contraction coupling of rat mesenteric resistance arteries lies distal to the receptor site.

In vitro studies were performed with rat mesenteric resistance arteries (diameter 158-271 microns) mounted as ring preparations in an isometric myograph. Noradrenaline evoked concentration-dependent, tonic contractions in calcium-containing media, whereas transient responses were elicited by the agonist in a concentration-dependent manner in calcium-free media; the pD2 values (-log EC50) were 6.73 and 5.71, respectively. The responses to noradrenaline in calcium-containing media were competitively inhibited by the alpha 1-selective antagonist, prazosin (pA2:9.23), and the responses to noradrenaline in calcium-free media were abolished by 10 nM prazosin. The agonist affinities expressed as the pKD values (-log KD) for the receptor mediating the response to noradrenaline in calcium-containing and calcium-free media were 5.78 and 5.64, respectively. These data suggest that although much higher concentrations of noradrenaline are required to elicit responses in calcium-free media than in calcium-containing media, both types of response are mediated by one adrenoceptor subtype, the alpha 1-adrenoceptor.

Animals↗
PubMed1990

[Bacteremia caused by zoonotic Salmonella types in greater Copenhagen in 1984-1988].

The five departments of clinical microbiology in Greater Copenhagen have together carried out a retrospective review of bacteraemia caused by the zoonotic Salmonella serotypes in the period 1984-1988 in the municipalities of Copenhagen and Frederiksberg and in the County of Copenhagen. A gradual increase in frequency was observed from 11 cases in 1984 to 58 cases in 1988. The serotype most commonly isolated was Salmonella dublin followed by Salmonella enteritidis and Salmonella typhimurium. S. dublin was found to be more invasive and more virulent than the other serotypes. Predisposing factors were present in 56% of the patients; the commonest of these was malignant disease. Fatal or complicated course of the disease were observed more frequently in predisposed patients than in persons who had previously been healthy. A total of 17% of the patients died and one fourth of these had ruptured aortic aneurysm probably on account of Salmonella arteritis. 20% developed recurrence of bacteraemia while in the remaining patients the disease ran an uncomplicated course. It is concluded that the marked increase in the number of cases and the serious course taken by the infection demonstrate a definite need for increased prophylactic efforts in the food industry.

Adolescent↗
PubMed1990

Decreased tetranectin in multiple myeloma.

Tetranectin, a recently described human protein widely distributed in the body and with possible importance for cell growth and differentiation, has previously been observed to be decreased in patients with solid malignant tumors. In patients with multiple myeloma, either untreated or previously treated, serum levels were found to be significantly reduced. A negligible interindividual variation was observed. Levels of serum tetranectin were not correlated with serum albumin, hemoglobin, or M-component. Low levels of tetranectin may be related to the growth and spread of malignant cells or reflect a general catabolic state of chronic disease.

Aged↗
PubMed1990

Sexual dysfunction in male and female patients with epilepsy: a study of 86 outpatients.

Sexual dysfunction is a well-known complication of chronic somatic illness. Eighty-six consecutive epileptic outpatients, 38 men and 48 women, without accompanying disorders, were studied. The frequency and symptoms of sexual dysfunction were compared with results from previous studies using identical sexological methodology. The previous studies were of diabetic patients and healthy controls. Eight percent of the epileptic men reported a sexual dysfunction compared to 44% of the diabetics and 13% of the controls. Epileptic women, diabetic women, and controls showed no significant differences in sexual dysfunction (29%, 28%, and 25%, respectively). In both sexes, the sexual function measured by frequencies of coitus and masturbation was normal. Most patients had good control of epileptic attacks on a treatment of monotherapy. Hormonal status was generally within normal limits in both men and women; only a few minor differences were found and they showed no correlation with sexual dysfunction. Psychologically and socially the patients did not differ appreciably from normals, and they exhibited a high degree of disease acceptance. This study, using a biopsychosocial approach in understanding sexual dysfunctions, is in contrast with previous, mainly uncontrolled, studies of epileptic patients that reported high frequencies of "hyposexuality" in males. We conclude that epilepsy does not necessarily increase the risk of sexual dysfunction in male or female.

Adult↗
PubMed1990

The effect of ranitidine on cellular immunity in patients with multiple myeloma.

Multiple myeloma is characterized by an increased susceptibility to infections and to other malignancies. In a double-blind, placebo-controlled study the potential impact of immunomodulation by ranitidine was studied in 20 patients with multiple myeloma. Three patients were untreated, while 17 after previous cytotoxic therapy were in a stable phase of their disease. All were without clinical signs of infections and at that time had not been treated with other immunomodulating agents. The patients were randomized to oral ranitidine 300 mg twice a day for 21 days or placebo, and several immunological parameters related to multiple myeloma were studied. The blood monocyte chemotactic response was improved in patients treated with ranitidine, and superoxide anion production increased from 2.02 nmol/min to 3.86 nmol/min (median values), while it was unchanged in patients given placebo (2.19-2.25 nmol/min) (P less than 0.005 between groups). Among ranitidine-treated patients spontaneous NK cell activity was unchanged, while in vitro interleukin-2- and interferon-alpha-stimulated NK cell activity decreased (P less than 0.03, respectively). As production of oxygen radicals constitutes an important mechanism of monocyte killing activity against microorganisms and probably against malignant cells, it is suggested that ranitidine may be of beneficial impact in the treatment of multiple myeloma.

Adjuvants, Immunologic↗
PubMed1990

Comparison of primary and secondary 26S rRNA structures in two Tetrahymena species: evidence for a strong evolutionary and structural constraint in expansion segments.

We have determined the nucleotide sequence of the 26S large subunit (LSU) rRNA genes for two Tetrahymena species, T. thermophila and T. pyriformis. The inferred rRNA sequences are presented in their most probable secondary structures based on compensatory mutations, energy, and conservation criteria. The majority of the nucleotide changes between the two Tetrahymena LSU rRNAs and the positions of a relatively large deletion and of the processing cleavage sites resulting in the generation of the hidden break are all located within the so-called divergent domains or expansion segments. These are regions within the common core of secondary structure where expansions have taken place during the evolution of the rRNA of higher eukaryotes. The dispensable nature of some of the expansion segments has been taken as evidence of their non-functionality. However, our data show that a considerable selective constraint has operated to preserve the secondary structure of these segments. Especially in the case of the D2 and D8 segments, the presence of a considerable number of compensatory base changes suggests that the secondary structure of these regions is of functional importance. Alternatively, these expansion segments may have maintained characteristic folding patterns because only such structures are being tolerated within otherwise functionally important regions.

Animals↗
PubMed1990

Differential distribution of postjunctional alpha 2 adrenoceptors in human omental small arteries.

A pharmacologic characterization of the postjunctional alpha adrenoceptors of human omental small arteries was performed using a microvascular myograph. Both the alpha 1-selective agonist phenylephrine in the presence of yohimbine (0.3 microM, alpha 2-selective antagonist) and the alpha 2-selective agonist B-HT 933 in the presence of prazosin (0.3 microM, alpha 1-selective antagonist) evoked strong vasoconstriction. The responses to phenylephrine were competitively antagonized by prazosin, whereas the responses to B-HT 933 were competitively antagonized by yohimbine; the pA2-values were 9.24 and 8.34, respectively. An inverse relationship of the maximum response to B-HT 933 (r = -0.53; p less than 0.001), but not to phenylephrine or to norepinephrine (NE), against artery caliber was observed. The shifts of the NE concentration-response curves caused by yohimbine (0.1 microM) were more marked in the smaller rather than the larger vessels (r = -0.71; p less than 0.01), whereas the opposite was observed using 0.1 microM prazosin (r = 0.84; p less than 0.001). These data suggest that both alpha 1 and alpha 2 adrenoceptors are present in the human omental small arteries, but whereas postjunctional alpha 2 adrenoceptors appear to be located predominantly in the resistance arteries, postjunctional alpha 1 adrenoceptors appear to be distributed evenly along the arterial tree.

Adult↗
PubMed1990

Responses to noradrenaline in human subcutaneous resistance arteries are mediated by both alpha 1- and alpha 2-adrenoceptors.

1. In vitro experiments in a microvascular myograph were designed to characterize postjunctional alpha-adrenoceptors of human subcutaneous resistance arteries (normalised internal diameter 143-313 microns). 2. Both the alpha 1-selective agonist phenylephrine in the presence of 0.3 microM yohimbine and the alpha 2-selective agonist B-HT 933 in the presence of 0.3 microM prazosin elicited prominent and concentration-dependent contractions. The maximum response to phenylephrine and B-HT 933 was not different from the response to high K physiological salt solution (125 mM K+), and the pD2 values (-log EC50) were 5.90 and 6.11, respectively. 3. In the presence of the alpha 2-selective antagonist yohimbine (0.3 microM), the alpha 1-selective antagonist prazosin competitively antagonised the responses to phenylephrine; the pA2 of prazosin for the receptor which mediated the response to phenylephrine was 8.41. 4. Blockade of either alpha 2-adrenoceptors with 0.1 microM yohimbine or alpha 1-adrenoceptors with 0.1 microM prazosin caused shifts to the right of the noradrenaline concentration-response curves and the shifts in pD2 were 0.69 and 0.61, respectively. The combination of the two antagonists at the above-mentioned concentrations caused a marked, parallel shift to the right of the noradrenaline concentration-response curve, the shift of the pD2 was 2.68. 5. These results suggest that activation of both alpha 1- and alpha 2-adrenoceptors produces contractions in human subcutaneous resistance arteries, and that responses to noradrenaline in these vessels are mediated by both alpha-adrenoceptor subtypes.

Adrenergic alpha-Agonists↗
PubMed1990

Further ultrastructural findings in epithelial cells of hairy leukoplakia.

Epstein-Barr virus and multivesicular structures appearing in lesions of hairy leukoplakia have been examined ultrastructurally in serial sections. It was found that both structures probably represent various levels of sectioning of transversely cut cell processes. The so-called viral nucleocapsid having a single membrane results when the plane of section is at right angles to one of the membranes but tangential to the other. While the so-called viral particle having two membranes would result if the plane of section is perpendicular to both the membranes of adjacent cells. The internal electron-dense core probably represents filaments enclosed within these processes and therefore does not represent DNA nucleotides. In addition, these nuclei contained bundles of filaments which probably represented tonofilaments. This was found to be due to tangential sectioning of the nuclear membrane surrounding deep cytoplasmic invaginations which led to the appearance of these filaments as if free within the nucleus.

Capsid↗
PubMed1990

Comparison of alveolar macrophage and blood monocyte oxidative burst response in pulmonary sarcoidosis.

The alveolitis of sarcoidosis is dominated by lymphocytes and mononuclear phagocytes and chronic macrophage activation may play a role in the pulmonary interstitial fibrosis of sarcoidosis. We measured superoxide anion release of alveolar macrophages from sarcoidosis patients after in vitro stimulation, as toxic oxygen radicals have been proposed as mediators of chronic tissue damage. In untreated patients alveolar macrophage activity was normal, but significantly lower than in blood monocytes. However, a negative correlation between lymphocytosis in bronchoalveolar lavage fluid and macrophage oxidative metabolism was observed, showing that only patients with high intensity alveolitis have a decreased oxidative burst response after in vitro stimulation. This may reflect in vivo activation of the cells with subsequent reduced ability to respond after additional stimulation in vitro. Patients with radiological stage I had lower alveolar macrophage response than patients in stage II or III. There was no correlation with SACE levels, lung function tests or smoking habits. Nine patients were reinvestigated after treatment with prednisolone. Although the lymphocytosis of lavage fluid was only insignificantly changed, all but one patient showed improved macrophage release of superoxide anion. Blood monocyte oxidative burst response was normal in all patients before and after treatment. In conclusion, only mononuclear phagocytes of the target organ (lung) showed an altered function and the most pronounced decrease was observed in sarcoid patients with active alveolitis. Chronic low grade toxic oxygen radical release of alveolar macrophages may be involved in the pathology of pulmonary sarcoidosis.

Adult↗
PubMed1990

Neurally evoked responses of rat mesenteric resistance arteries are dependent on intracellular release of calcium.

Rat mesenteric resistance arteries (diameter less than 250 microns) were isolated and mounted in a myograph, and experiments were designed to test whether neurally evoked responses of these vessels are dependent on intracellular release of calcium. The responses to nerve stimulation were completely abolished in calcium-free media, and the possible contribution of intracellular release of calcium could therefore not be examined by switching to a calcium-free solution. Instead, the vessels were stimulated intermittently for 5 s at intervals of 90 s. Following 5 s of nerve stimulation, the intracellular calcium stores were depleted by application of 25 mM caffeine for 15 s. Vessels were then bathed in calcium-free saline, and subsequently 2.5 mM Ca2+ was replaced at varying times prior to nerve stimulation. With 5 s allowed for calcium repletion, the response to nerve stimulation was significantly smaller than the nerve response after 40 s in calcium-containing saline. The results suggest that the response to nerve stimulation is dependent on the time allowed for the intracellular store to refill, implying that intracellular release of calcium is a critical determinant of the neurogenic response in resistance arteries.

Animals↗
PubMed1990

Candida norvegensis peritonitis and invasive disease in a patient on continuous ambulatory peritoneal dialysis.

We report a case of Candida norvegensis invasive disease in an immunosuppressed renal transplant patient on continuous ambulatory peritoneal dialysis. Multiple cultures of peritoneal fluid, blood, and tracheal suction done over a 2-week period were positive for this unusual isolate. Despite treatment with amphotericin B and flucytosine the patient died. This is the first report of C. norvegensis fungemia documented by culture.

Adult↗
PubMed1990

Short chain fatty acids dilate isolated human colonic resistance arteries.

Colonic biopsy specimens were obtained from patients undergoing surgery for carcinoma of the rectum. Colonic resistance arteries (internal diameter 178-345 microns) were dissected out under the microscope and mounted in a microvascular myograph capable of measuring isometric tension development. Experiments were designed to test compounds trophic to the gastrointestinal tract--namely, glutamine and the three short chain fatty acids, acetic, propionic, and butyric acid, for effects on vascular tone. Glutamine in concentrations up to 30 mM neither constricted nor dilated the resistance arteries. The three short chain fatty acids alone and in combination, however, caused a concentration-dependent (range 0.1-30 mM) dilatation of resistance arteries preconstricted with 50 mM K+, and this relaxant effect was unaffected by removal of the endothelium, presence of indomethacin, and preconstriction with vasopressin. These data suggest that the trophic effect of glutamine on intestinal mucosa cannot be explained through actions of this compound on the resistance vasculature. In contrast, the relaxant effect of short chain fatty acids on resistance arteries in vitro suggests that these compounds may be able to improve the colonic microcirculation in vivo, thereby providing an explanation for their trophic effect on intestinal mucosa.

Adult↗
PubMed1990

Fungemia with Saccharomycetaceae. Report of four cases and review of the literature.

Invasive fungal disease with Saccharomycetaceae is very rarely reported and these fungi are usually considered nonpathogenic. We report here 4 cases of positive blood cultures with fungal species belonging to this family. Severe neutropenia, permanent central venous catheter, ongoing antibacterial chemotherapy, and major abdominal surgery were identified as risk factors for fungemia in patients. In the immunocompromised host isolation of such species from sterile fluids cannot be ignored but should be considered an opportunistic infection and treated as such.

Abdomen↗
PubMed1990

Harmonic distortion measurements in clinical hearing and fitting. Preliminary report.

Measurement of the distortion from hearing aids and its influence on their fitting has become practicable with the implementation of real ear measurement in the audiological clinic. Thus the harmonic distortion measured in the ear fitted with the hearing aid can be measured by means of a probe in the ear canal. The objective of the present investigation was to examine the value of harmonic distortion measurements in the fitting of hearing aids within a clinical setting. The material comprised 101 consecutive patients who had been prescribed different types of hearing aids based on the POGO formula, using insertion gain measurements. 160 hearing aids were fitted and with the fitting strategy used, a distortion less than 10% was indicated in 122 fittings (76%), a distortion between 10 and 20% in 30 fittings (19%) and finally a distortion greater than 20% in 8 fittings (5%). In the cases with the distortion greater than 10%, the hearing aid setting was maintained and the magnitude of the harmonic distortion was controlled with a 2-cc coupler. At the hearing aid fitting, the audiology technician can listen to the signal at the patient's drum and thus may hear distortion products. The relationship between the 'distortion' heard by the audiology technician and the 'distortion' heard by the patient was fairly good. Based on these preliminary findings it is concluded that harmonic distortion measurements may prove useful in the hearing aid fitting procedure.

Adolescent↗