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Biomedical subjects

S Jepsen

Publications and source records attributed to S Jepsen.

At least 73 records · Page 4Linked to original sources
PubMed1990

Biochemical characterization, localization and immunostimulating properties of a soluble glycoprotein, Ag1, isolated from in vitro cultures of Plasmodium falciparum.

The soluble amphiphilic glycoprotein, Ag1 (gp60), purified from supernatants of in vitro cultures of Plasmodium falciparum has a molecular mass of 60 kDa and did not exhibit size variation in the different P. falciparum isolates tested by immunoblotting. Ag1 was shown to interact with the lectin Erythrina christagalli agglutinin, which is specific for carbohydrates bearing beta-D-galactose(1-4)-D-N-acetylglucosamine. Indirect immunofluorescence studies showed that Ag1 is located on the surface of trophozoites and schizonts but not on the surface of merozoites. Ag1 is recognized by human immune sera from six different malaria-endemic regions. Ag1 induces in vitro proliferation of lymphocytes from malaria-immune individuals in an antigen-specific manner.

Animals↗
PubMed1990

Reduced cellular immune reactivity in healthy individuals during the malaria transmission season.

Antigen-induced cellular immune responses are suppressed during acute malaria. The present study engages the possibility that malaria-induced alterations in cellular immune reactivity extend beyond the clinical disease. Thus, lymphoproliferative responses of healthy individuals were diminished during the malaria transmission period in individuals living in an area of highly seasonal, unstable malaria transmission. This finding may have important implications for the design of studies of stimulatory properties of antigens using lymphocytes of endemic origin.

Adolescent↗
PubMed1990

Cell-mediated immune responses to Plasmodium falciparum purified soluble antigens in sickle-cell trait subjects.

To determine the possible differences in the immune response to Plasmodium falciparum between sickle-cell trait (Hb AS) and normal haemoglobin (Hb AA) individuals, we examined 35 Hb AS and 24 Hb AA subjects matched for age and microenvironment. Their age was 2-55 years and all lived in a malaria endemic area 300 km south of Khartoum. Antibodies to ring-infected erythrocyte surface antigen (Pf155/RESA) and to circumsporozoite (CS) protein (anti-NANP40) indicated equal exposure to falciparum malaria. Peripheral blood mononuclear cells (BMNCs) from 20/35 (57%) Hb AS subjects compared with 10/24 (42%) Hb AA subjects, responded to affinity-purified P. falciparum soluble antigens (SPAg). Of those responding to SPAg, 9 (26%) Hb AS subjects and only two (8%) Hb AA subjects had high responses. The mean proliferative response to SPAg of BMNCs from Hb AS individuals was significantly higher than in Hb AA individuals (P less than 0.025). Responses of BMNCs to PPD and PHA were also higher among Hb AS individuals and correlated positively with responses to SPAg. These findings support the hypotheses that the sickle-cell trait protects individuals from P. falciparum infections, at least in part, by modulating the immune response.

Adolescent↗
PubMed1990

An epidemic outbreak of cryptosporidiosis: a prospective community study from Guinea Bissau.

In the first year of a prospective community study of childhood diarrhea conducted in a semiurban area in the capital of Guinea Bissau, Cryptosporidium sp. was found in 73 (6.0%) of 1216 episodes of diarrhea. The parasite was the second most prevalent intestinal parasite, and the only one significantly associated with diarrhea (OR = 2.79, P = 0.0006). The seasonal distribution was striking, with a peak prevalence in the beginning of the rainy season (May 17.6%) when an epidemic outbreak of diarrhea started. The prevalence was highest in children younger than 18 months, an age at which prevalences of other intestinal parasites were low. This reverse age pattern may possibly be explained by the small infective dose needed to create severe infections, by air-borne transmission and by the development of protective immunity.

Cryptosporidiosis↗
PubMed1990

Cell-mediated immune responses to soluble Plasmodium falciparum antigens in residents from an area of unstable malaria transmission in the Sudan.

This paper describes immune responses to P. falciparum infection in individuals living in an area of highly seasonal, unstable malaria transmission. The in vitro cellular immune responses of peripheral blood mononuclear cells (PBMC) from 36 Sudanese donors to a complex of affinity purified soluble P. falciparum antigens (SPag) and two components thereof (Ag1 and Ag7) were examined and compared to humoral immune parameters. In 29/36 Sudanese donors, SPag induced a significant lymphoproliferative response in vitro. In contrast only 3/27 Danish donors never exposed to malaria responded to SPag. Ag1 and Ag7 induced significant lymphoproliferation in 9/34 and 13/36 Sudanese donors respectively, whereas no Danish donors responded. Significant interferon-gamma production was observed in 16/27, 1/5 and 3/12 Sudanese donors when stimulated by SPag, Ag1 and Ag7 respectively. Lymphoproliferative responses to SPag correlated with proliferative responses to Ag1 and Ag7, and with Spag-induced interferon-gamma production. These results indicate that T-cell clones recognizing epitopes on Ag1 and Ag7 have been expanded in the studied population as a result of exposure to P. falciparum infection. The T-cell parameters did not correlate with the presence of antibodies to SPag, Pf155/RESA or a crude parasite sonicate or with the schizont IFA titers of the plasma. This indicates that parameters outside the degree of exposure to P. falciparum influence the cellular immune responses to malaria.

Adult↗
PubMed1990

Varicella among immigrants from the tropics, a health problem.

The incidence of varicella in Tamil refugees in Denmark was evaluated. Of 256 Tamils, 44% developed varicella infection in the first few months after arrival, representing 38% of the adults, and 68% of the children. During approximately four months' observation in Denmark, 75% of the refugees with no history of varicella developed a typical infection whereas only 2% of those with a history of varicella developed the disease. Tropical refugees with a negative history of varicella must therefore be considered nonimmune. Nine of 44 fertile women were pregnant. Two acquired the varicella infection during the first-trimester, none in relation to delivery. By organizing a health-check on arrival, prophylactic measures can reduce the health hazard of varicella infection in refugees from the tropics.

Adolescent↗
PubMed1990

Salmonella and Shigella carriers among refugees from the middle east and Sri Lanka in Denmark.

One per cent of ten thousand refugees were asymptomatic carriers of Salmonella and Shigella species found by a differentiated health check programme at a Danish Red Cross arrival centre in Denmark 1985 and 1986. Six patients with typhoid fever and one with S. parathyphi-A septicaemia all fell ill within the first few weeks after arrival. A child of a chronic S. typhi carrier developed typhoid fever four months after arrival. Cases of sporadic and mild diarrhoea occurred due to Salmonella and Shigella species. The carriers were instructed in prophylactic, hygienic measures and no outbreaks developed. The health check system in this period seemed to be sufficient in relation to preventing outbreaks of infections caused by non-typhoid Salmonella and Shigella species. The relative cost-effectiveness of a more intensive S. typhi screening on arrival is questionable. The organization of health check systems should be reviewed regularly, as each refugee situation is different and will change in different periods.

Carrier State↗
PubMed1989

[Treatment of cardiac arrest. Recent aspects of cardiopulmonary resuscitation].

Opinions are still not unanimous about the mechanism behind circulation during external cardiac compression and this leads to uncertainty regarding the correct frequency, force of compression and its duration. Adrenaline and other alpha-stimulators increase blood flow during external cardiac compression and increase survival. Cardiac arrest results in anaerobic metabolism and combined metabolic and respiratory acidosis. On account of relatively low minute volume during external cardiac compression decrease in end-tidal carbon dioxide concentration is observed together with arterial alkalosis on account of hyperventilation and venous acidosis. No communications exist about the favourable effect of administration of bicarbonate during cardiac arrest. On the other hand, several conditions suggest that bicarbonate increases the intracellular acidosis with poorer possibilities for resuscitation with this form of treatment. Ischaemia results inter alia in intracellular accumulation of calcium which initiates potential cell destructive processes. No investigations are available which favour employment of calcium during cardiac arrest. Conversely animal experiments suggest the possibility of favourable effects from calcium-entry blockers. Ischaemia and, in particular, reperfusion release cell and vessel damaging free oxygen redicals. Intensive investigations are being conducted at present about the value of anti-oxidants for cerebral and myocardial protection.

Heart Arrest↗
PubMed1989

[The effect of systemic N-acetylcysteine on postoperative expectoration. A prospective, randomized double-blind study].

A material of 110 consecutive patients submitted to elective upper abdominal laparotomy participated in a randomized double-blind investigation of the effect of N-acetylcysteine (Mucomyst) administered systemically in the recommended dosage on postoperative expectoration. As an effect variable the quantity of expectorate and the viscosity as assessed subjectively by the physiotherapists in the department on a visual analog scale was employed. N-acetyl-cysteine was not found to have any effect on the postoperative expectoration as assessed by the quantity and the viscosity.

Clinical Trials as Topic↗
PubMed1989

Bacterial contamination of stored water and stored food: a potential source of diarrhoeal disease in West Africa.

The food and water hygiene in two Liberian communities was studied in a house-to-house diarrhoea survey. The level of contamination with enterobacteria of drinking water stored in the households was significantly higher than at the water sources. Food hygiene standards were low, particularly in the urban slum where storage of cooked food for long periods led to bacterial multiplication at high levels. Infant foods were particularly heavily contaminated. It is concluded that when water supply programmes are planned, the presence of other risk factors for water-related diseases should be investigated. To ensure maximum health benefits, water projects should as a rule be accompanied by other interventions.

Child, Preschool↗
PubMed1989

Systemic administration of N-acetylcysteine has no effect on postoperative lung function following elective upper laparotomy in lung healthy patients.

In a randomized, double-blind study, 131 consecutive patients, subjected to elective upper laparotomy, were prophylactically given the recommended dose of N-acetylcysteine (NAC) (Mucomyst, ASTRA) (200 mg x 3) or placebo against postoperative pulmonary complications. The effect was evaluated by lung function tests (VC and FEV1), arterial blood gas analyses and chest x-ray. No benefit could be demonstrated, either to postoperative pulmonary function or in the frequency of atelectasis in the recommended dose. However, no patients with preoperative bronchopulmonary disease demanding treatment with bronchodilatators were included in the study. A positive effect of NAC in this category of patients could not be excluded.

Acetylcysteine↗
PubMed1989

Peroral N-acetylcysteine as prophylaxis against bronchopulmonary complications of pulmonary surgery.

In a randomized, double-blind study, 38 patients undergoing elective pulmonary surgery were given N-acetylcysteine (Fabrol, Ciba-Geigy) in recommended dosage (200 mg X 3) or placebo. The prophylactic effect on postoperative bronchopulmonary complications was evaluated from arterial blood-gas analyses and chest radiography. The alveolo-arterial oxygen difference increased substantially and similarly in both patient groups, and no intergroup difference was found in incidence of atelectasis or pneumonic infiltration. Thus there was no demonstrable benefit of N-acetylcysteine in the recommended dosage. For future similar studies, employment of considerably higher doses is proposed.

Acetylcysteine↗
PubMed1989

Early diagnosis of postoperative pneumonia following upper abdominal surgery. A study in patients without cardiopulmonary disorder at operation.

In 130 patients with no cardiac or pulmonary disease at the time of elective upper abdominal surgery, chest radiography was performed 2 and 4 days postoperatively. The sputum was examined and the patients were monitored with measurement of body temperature, arterial oxygen tension and white blood counts. Pneumonic infiltrates appeared in 8.4% of the patients and atelectasis in 68.5%. Most of the patients had elevated body temperature, raised white blood count and reduced arterial oxygen tension postoperatively. None of these commonly employed clinical or laboratory findings, singly or in combination, proved adequate for diagnosis of postoperative pneumonia.

Aged↗
PubMed1988

Malaria chemoprophylaxis in travellers to east Africa: a comparative prospective study of chloroquine plus proguanil with chloroquine plus sulfadoxine-pyrimethamine.

As malaria caused by Plasmodium falciparum has become resistant to chloroquine alternative drug regimens need to be developed. The prophylactic efficacy against malaria and the side effects of chloroquine phosphate 500 mg weekly with proguanil hydrochloride 200 mg daily was compared with the efficacy of chloroquine 500 mg weekly with sulfadoxine 500 mg-pyrimethamine 25 mg weekly in a randomised study of Scandinavian travellers to Kenya and Tanzania during 1984-5. A total of 767 subjects (416 male and 351 female; 384 taking chloroquine phosphate with proguanil hydrochloride and 383 taking chloroquine with sulfadoxine-pyrimethamine) completed a diary on the breakthrough of malaria and the side effects of treatment while taking the drugs. They were also asked to make thick blood films when symptoms like those of malaria occurred, which were sent to and analysed in Denmark. Four subjects taking chloroquine with proguanil hydrochloride and three taking chloroquine with sulfadoxine-pyrimethamine developed falciparum malaria, which was verified microscopically. Side effects were reported by 36 subjects taking chloroquine phosphate with proguanil hydrochloride and 55 taking the other regimen (p = 0.043). The side effects of both regimens were generally mild, but the combination of chloroquine phosphate with proguanil hydrochloride is recommended because it results in fewer side effects. As breakthroughs of malaria occurred at the earliest after seven weeks self treatment should not be recommended for travellers staying only a short time. Thick blood films are useful for diagnosis of suspected cases of malaria, can be prepared by non-specialists in Africa, and can be analysed successfully after long delays.

Adult↗
PubMed1988

Demonstration of soluble Plasmodium falciparum antigens reactive with Limulus amoebocyte lysate and polymyxin B.

To investigate whether soluble Plasmodium falciparum antigens possess endotoxin-like properties, the interaction of Limulus amoebocyte lysate (LAL) with defined soluble antigens from Plasmodium falciparum was studied by various crossed immunoelectrophoretic methods and immunoblotting. The soluble P. falciparum antigens were purified by affinity chromatography using human IgG from malaria-immune adults as ligand. Of eight possible antigens, at least three were affected by LAL, as indicated by disappearance of these antigens in the precipitation pattern, after the reaction with LAL. One of the LAL-reactive antigens is a heat-stable glycoprotein with the presence of both hydrophilic and hydrophobic regions in its structure. This antigen shows a strong reaction with polymyxin B, and antibodies against it have been shown to be inhibitory to the growth of P. falciparum in culture. It is concluded that LAL reacts with several soluble antigens from P. falciparum and it is suggested that these antigens participate in the induction of protective immunity to malaria, and consequently that one or more of the soluble antigens are candidates for a malaria vaccine.

Animals↗