PubMed Health⌕ Search

Biomedical subjects

H Willems

Publications and source records attributed to H Willems.

At least 37 records · Page 2Linked to original sources
PubMed1995

D-lactic acidemia and aciduria in pediatric and adult patients with short bowel syndrome.

D-Lactate produced by abundant intestinal lactobacilli during acidotic episodes in short bowel (SB) patients is commonly regarded as a main factor in the pathogenesis of SB syndrome-associated (D-lactic) acidosis. Since we had observed that gram-positive bacteria, mainly lactobacilli, were abundant even in the absence of acidosis, we studied serum concentrations and urinary excretions of D- and L-lactate in young and adult SB patients, especially during nonacidotic periods. Serum L-lactate and urinary L-lactate excretion were similar in adults and children. Serum D-lactate and urinary D-lactate excretion were higher in SB children than in SB adults. Food consumption affects D-lactate production and alters D-lactic acidemia and aciduria. We conclude that D-lactate is frequently present in serum of SB patients even in the absence of acidosis. High serum concentrations and urinary excretions may reflect dietary factors in these patients.

Acidosis, Lactic↗
PubMed1994

Analysis of the entire nucleotide sequence of the cryptic plasmid QpH1 from Coxiella burnetti.

The complete plasmid QpH1 from Coxiella burnetti, isolate 'Nine Mile', phase I, was cloned as NotI fragment with a size of 37329 bp. The entire plasmid was sequenced by the chain termination method after EcoRI subcloning. 37 open reading frames coding for polypeptides larger than 100 amino acid residues were determined. The predicted polypeptide products of the open reading frames were compared by computer analysis with reported protein sequences. Homologies of predicted polypeptide products to analogous proteins are described.

Amino Acids↗
PubMed1994

The 16S/23S ribosomal spacer region of Coxiella burnetti.

The 16S/23S spacer region of Coxiella burnetti isolate Nine Nile, phase 1, was sequenced. Sequence analysis revealed two tRNA coding regions for tRNA(Ile) and tRNA(Ala). DNA sequence alignment demonstrated significant homology with tRNA species from Pseudomonas aeruginosa and Rhodobacter sphaeroides, respectively. The non-coding tRNA spacer region was unique to Coxiella burnetti, based on database alignment.

Cloning, Molecular↗
PubMed1994

Is plasmid based differentiation of Coxiella burnetii in 'acute' and 'chronic' isolates still valid?

Ten human Coxiella burnetii isolates from french patients with acute hepatitis or chronic endocarditis were characterized according to their polymorphism in DNA restriction patterns and differentiated by plasmid-specific PCR. The aim of this investigation was to clarify if the present classification of so called 'acute' and 'chronic' Coxiella burnetii isolates--based on plasmid profile of a so far limited number of partly ancient isolates--could be confirmed with lately isolated organisms of this agent. The data obtained in this investigation indicate that this classification based on C. burnetii plasmid content is no longer justified.

Acute Disease↗
PubMed1994

Detection of Coxiella burnetii in cow's milk using the polymerase chain reaction (PCR).

A PCR approach (transposon PCR) with primers based on repetitive transposon-like sequences, which--depending on the isolate--were found at a minimum frequency of 19 on the C. burnetii genome, was established for the highly sensitive and specific detection of C. burnetii. This study describes the analytical detection of C. burnetii in milk, which requires a special preparation method prior to PCR. Because of the low level of C. burnetii particles in milk samples, template DNA was concentrated by a factor of 200, using cetyltrimethylammonium bromide as the precipitation reagent. Using this particular preparation method, even a single C. burnetii particle could be detected in 1 ml milk.

Animals↗
PubMed1993

Plasmid based differentiation and detection of Coxiella burnetii in clinical samples.

A "nested" PCR approach with primers based on conserved plasmid sequences was used for the highly sensitive and specific detection of Coxiella (C.) burnetii in clinical samples collected from cattle, dogs, cats and humans. Results were in good agreement with those obtained from Capture-ELISA and isolation of the organism in BGM cell culture. We also tested primers with sequences derived from genomic DNA and sequences based on 16S rRNA. In addition, we applied PCR for the differentiation of C. burnetii plasmid types from 28 isolates originating from the USA, Europe and South Africa. Reference isolates Nine Mile RSA493, Dugway 5J108-111 and all European isolates tested were recognized only by primers specific for the QpH1 plasmid. One isolate from a goat abortion in Namibia reacted identically to the reference isolate Priscilla Q177 bearing the QpRS plasmid. Reference isolate S Q217 with plasmid sequences integrated into the genome reacted with none of the plasmid-specific primer pairs.

Animals↗
PubMed1993

Polymorphism in DNA restriction patterns of Coxiella burnetii isolates investigated by pulsed field gel electrophoresis and image analysis.

Pulsed field gel electrophoresis was used for differentiation of Coxiella burnetii isolates derived from animals in Europe and one from Namibia. Previously published data on isolates from North America demonstrated four groups with distinct banding patterns. Fingerprints of prototype isolates as references confirmed four different cleavage patterns upon NotI restriction of total DNA as described. With isolates available at our institute five additional DNA banding patterns were obtained from European and one Namibian isolate after endonuclease restriction with NotI. To compare patterns from different electrophoretic runs more precisely an image analysis system was used.

Animals↗
PubMed1993

Use and costs of antimicrobial drugs in medical wards of a central hospital in Malawi.

Economic constraints experienced by many African countries make it vital that reliable information is collected about the cost of patient care in health institutions. Case files and treatment charts of 509 patients admitted to non-fee paying medical wards of Queen Elizabeth Central Hospital, Blantyre, Malawi for the month of September 1992 were analysed in order to determine the amount and costs of drugs and antimicrobial agents given to inpatients. Infectious diseases accounted for 76% of all admissions. A total of 59 different drug items were used (cost U.S. $732). In all, 18 antimicrobial agents were given (31% of all drug items) at a cost of U.S. $615 (84% of all drug costs). Calculated costs of antimicrobial agents for each patient and for annual admissions (10325 in 1992) were U.S. $1.21 and U.S. $12,558 respectively. Although the present study has its limitations, it provides a rational basis for planning departmental drug budgets.

Anti-Bacterial Agents↗
PubMed1992

Immunoblot technique for Q fever (technical note).

Partially purified but unfixed C. burnetii cells were submitted to sodium dodecylsulfate polyacrylamide gel electrophoresis, Western blotted and used as antigens for evaluation of antibody responses against the agent in mice, cattle and humans. Increased specificity was achieved by using glutaraldehyde as additional blocking agent. Gels as well as membranes were subjected to laser densitometry and data analysed with an IBM personal computer. This technique offers the possibility to objectively quantify and document the results of immunoblotting.

Animals↗
PubMed1992

Immunoblot analysis of IgG subclass antibody response against Coxiella burnetii in Balb/c mice.

Balb/c mice were inoculated with live or inactivated organisms of Coxiella burnetii, strain Nine Mile, phase I. Sera collected after different time intervals were subjected to immunoblot analysis and results compared with ELISA values. Immunoblots were performed with different horseradish peroxidase labelled conjugates (goat anti-mouse IgG1, IgG2a, IgG2b, IgG3) and results monitored and analysed by laser densitometry. ELISA analysis was performed using the same peroxidase labelled goat anti-mouse subclass antibody conjugates. In addition, goat anti-mouse IgG(H+L), IgG(H), IgM, and IgA conjugates were used for ELISA tests.

Animals↗
PubMed1991

Mechanisms of sudden cardiac death.

Although coronary artery disease is the most frequent cause of sudden cardiac death, it may be caused by a heterogeneous group of disorders. Acute ischaemia is responsible for about half the cases of sudden death after acute myocardial infarction, and is manifested through ventricular fibrillation or polymorphic ventricular tachycardia. Several factors affect the haemodynamic consequences of a ventricular arrhythmia. Re-entry is the mechanism involved in patients with a history of myocardial infarction and therapy should be individualised and directed to the arrhythmia. Simple decision trees are available that can help to find the most appropriate therapy; implantable defibrillators are the most effective modality in certain very high risk subsets.

Arrhythmias, Cardiac↗
PubMed1990

Fibrinolytic responses to 1-desamino-8-D-arginine-vasopressin in patients with congenital nephrogenic diabetes insipidus.

Fibrinolytic responses to infusion of 1-desamino-8-D-arginine-vasopressin (DDAVP) were assessed in 6 males with congenital nephrogenic diabetes insipidus (NDI), 6 carriers of the NDI gene and 6 normal control subjects. Tissue-type plasminogen activator (t-PA) activity and antigen increased significantly in normal subjects, while plasminogen activator inhibitor (PAI) activity decreased. None of these changes were observed in patients with NDI. In 2 female carriers, normal fibrinolytic responses were seen, while in the other carriers responses were delayed. These findings are consistent with the concept of a general V2-receptor defect in congenital NDI. DDAVP tests are of limited use in NDI carrier detection.

Adult↗
PubMed1987

Pulmonary function and intradermal tests in workers exposed to soft-paper dust.

A survey was carried out in the processing department of a paper mill, consisting of environmental and personal monitoring, a short questionnaire concerning chronic non-specific lung disease (CNSLD), spirometry, and intradermal tests. Spirometry was performed on Monday, Wednesday, and Friday. Exposures to paper dust regularly exceeded the Dutch Maximal Allowable Concentrations (MACs) for total and respirable dust. There were indications of a qualitatively different exposure to molds inside the mill in comparison with the outdoor air. A comparison between a group of workers exposed to paper dust and a control group showed significantly more persons with positive late and delayed intradermal test reactions in the exposed population. The analysis of the spirometric measurements after correction for differences between the groups in age, height, and smoking habits gave evidence of the existence of lower FEV1, MMEF, MEF50, and MEF25 among exposed workers with a positive immediate intradermal reaction on Friday. The same workers showed a decline in pulmonary function over the week compared with the controls. These changes suggest an obstructive airway reaction with an immunologic mechanism to dust exposure in a paper mill.

Humans↗
PubMed1986

Cyclooxygenase-catalyzed formation of 9-hydroxylinoleic acid by guinea pig alveolar macrophages under non-stimulated conditions.

Data are presented on the formation of a linoleic acid oxygenation product under basal conditions by guinea pig alveolar macrophages (AM). Under non-stimulated conditions 20 X 10(6) AM released about 1 nmol 9-hydroxylinoleic acid (9-HODE) during a 15 min incubation. Furthermore, AM released more than 2 nmol 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT), a byproduct of the formation of thromboxane A2. 9-HODE and HHT were the most prominent products formed under the incubation conditions used. These products were formed via a cyclooxygenase-catalyzed reaction, since their formation was inhibited by 1 microM indomethacin. Thus, under basal conditions AM possess substantial cyclooxygenase activity. The biological significance of 9-HODE and related substances is discussed.

Animals↗