Biomedical subjects

L Mulder

Publications and source records attributed to L Mulder.

23 records · Page 2Linked to original sources

PubMed1997

Antineutrophil cytoplasmic antibodies in juvenile chronic arthritis.

OBJECTIVE: To evaluate the diagnostic significance of antineutrophil cytoplasmic antibodies (ANCA) by assessing the prevalence of ANCA in juvenile chronic arthritis (JCA) (n = 93) of either oligoarticular, polyarticular, or systemic onset. To investigate the prevalence of ANCA in other diseases of childhood characterized by chronic inflammation (n = 44), such as cystic fibrosis, juvenile diabetes mellitus, and connective tissue diseases. METHODS: Indirect immunofluorescence on both ethanol and paraformaldehyde fixed neutrophils, ELISA for specific antigens, Western blotting using sonicated neutrophils. RESULTS: ANCA were detected in the sera from 35% of patients with JCA, and in only 7% of patients with other inflammatory diseases. Regarding the onset type of JCA, ANCA were present in 44% of patients with oligoarticular onset, in 36% with polyarticular onset, and in 16% with systemic onset. All but one ANCA positive serum sample produced a perinuclear fluorescence pattern on ethanol fixed granulocytes. However, on neutrophils fixed with paraformaldehyde either a cytoplasmic (14%) or a nuclear (23%) staining pattern was observed, suggesting that both cytoplasmic and nuclear autoantibodies occur in JCA. Further characterization studies showed that ANCA in JCA are not directed against proteinase 3, elastase, or myeloperoxidase. On Western blots ANCA in JCA incidentally showed reactivity with either lactoferrin (5%) or 2 polypeptides of 66/67 kDa (9%). CONCLUSION: Prevalence and antigenic specificity of ANCA in JCA are clearly different from adult onset rheumatoid arthritis or other juvenile chronic inflammatory disorders.

Adolescent↗

PubMed1993

Occurrence of autoantibodies to human leucocyte elastase in Wegener's granulomatosis and other inflammatory disorders.

Antineutrophil cytoplasmic antibodies (ANCAs) constitute a new class of autoantibodies that seem to recognise myeloid lysosomal enzymes. The occurrence of ANCAs with specificity for human leucocyte elastase (HLE) was assessed in serum samples that were routinely submitted for ANCA determination. During a study period of more than six years anti-HLE was found in only six out of 1102 serum samples that produced a perinuclear or an atypical cytoplasmic staining pattern on ethanol fixed granulocytes. These six serum samples were from four patients with a clinical diagnosis of Wegener's granulomatosis but without a definite histological diagnosis, one patient with systemic vasculitis, and one patient with Cogan's syndrome. To further evaluate the prevalence of anti-HLE we tested 315 serum samples from patients with different forms of vasculitis and related disorders. Anti-HLE was detected in two patients only. Thus autoantibodies to HLE are rarely found in serum samples from patients with vasculitic or related disorders.

Aged↗

PubMed1993

Anthropophilic mosquitoes and malaria transmission at Edea, Cameroon.

An entomological study was carried out during 1990 in the town of Edea in the south of Cameroon to study anthropophilic mosquitoes with special reference to malaria transmission. Man-biting mosquitoes were caught regularly during one night each month in two different districts: Bilalang which is a well planned suburb with 160 houses on a hill-top, provided with a piped water supply; and Pongo which is a densely urbanised suburb in a valley. From 188 man-nights 1030 mosquitoes were collected, comprising 700 Culex quinquefasciatus (68%), 262 Anopheles gambiae (25%) and others species (7%) belonging to the genus Anopheles, Mansonia, Culex and Aedes. The estimated annual biting rates of mosquitoes were 811 bites per man in Bilalang and 2,866 in Pongo. The estimated yearly malaria inoculation rates were 3.8 and 30.2 infective bites per man in Bilalang and Pongo, respectively. In different parts of Pongo district much variation existed; extreme values of the estimated yearly inoculation rate were zero and 86.3 in two houses 200 m apart, located on the top of a hill and in the bottom of a valley, respectively. This study is one of the first conducted on malaria transmission in a moderate sized African town; it shows that the mosquito populations are typically urban and differ greatly from rural ones.

Aedes↗

PubMed1992

Segregation analysis detects a major gene controlling blood infection levels in human malaria.

The profound influence that the genetic makeup of the host has on resistance to malaria infection has been established in numerous animal studies. This genetic heterogeneity is one of the main causes of the difficulties in developing an effective malaria vaccine. Segregation analysis is the first step in identifying the nature of genetic factors involved in the expression of human complex diseases, as infectious diseases. To assess the role of host genes in human malaria, we performed segregation analysis of blood parasite densities in 42 Cameroonian families by using both the unified mixed model and the class D regressive model of analysis. The results provide clear evidence for the presence of a recessive major gene controlling the degree of infection in human malaria. Parameter estimates show a frequency of .44-.48 for the deleterious allele, indicating that about 21% of the population is predisposed to high levels of infection.

Adolescent↗

PubMedDate not supplied

[Evaluation of Plasmodium falciparum susceptibility to chloroquine and amodiaquine using a simplified, in vivo, 7-day test in southern Cameroon].

Plasmodium falciparum susceptibility to chloroquine and amodiaquine at a posology of 25 mg/kg per os in 3 days was evaluated in the pupils of 6 primary schools of South-West Cameroon during the first semester 1989. Parasitic index was 75%. Plasmodium falciparum was present in 96% of the infections 24% of the 357 children treated with chloroquine were carriers of trophozoites at D3 and 17% at D7. Complete resistance, at level R III, was observed in 4% of the children. By the 55 children treated with amodiaquine, 13% and 10% were carriers of few trophozoites at D3 and D7. The significance of these results is discussed.

Adolescent↗