Biomedical subjects

P L Van der Merwe

Publications and source records attributed to P L Van der Merwe.

9 recordsLinked to original sources

PubMed1998

Myosin-reactive autoantibodies in rheumatic carditis and normal fetus.

EBV-transformed B cells from a 20-week human fetal spleen and from blood of patients with poststreptococcal rheumatic carditis were studied. Most antibodies from nine fetal and six patient myosin-reactive B cell clones were multireactive (reacting with cardiac myosin, Streptococcus pyogenes, and rat cardiac myocytes) which supports a role for molecular mimicry in stimulation of these autoantibodies. Sequence analysis revealed that fetal and patient anti-myosin repertoires were composed of unrelated clones with diverse V gene usages. Fetal and patient antibodies had reduced VH CDR3 length on average and reduced light chain N region addition with a low rate of somatic mutation in the variable region genes, characteristics generally associated with fetal B cells but also with some adult B cells. Five of six myosin-reactive patient clones used VH3, whereas only two of nine fetal clones used VH3, suggesting skewing from the average 50-60% VH3 gene usage found in randomly selected adult and fetal antibodies.

Adult↗

PubMed1998

Second-degree atrioventricular heart block after doxapram administration.

Doxapram, a respiratory stimulant, is used to treat idiopathic apnea of prematurity. The side effects reported are minimal. We present three cases of second-degree atrioventricular block caused by QT interval prolongation associated with doxapram administration. All three infants returned to normal sinus rhythm after doxapram administration was stopped.

Apnea↗

PubMed1998

Cardiac tamponade following umbilical vein catheterisation in a neonate.

Umbilical vein catheterisation (UVC) should not routinely be used in the neonatal intensive care unit, and when it is used special precautions should be taken and guidelines followed. We present an unusual complication which occurred following use of an umbilical vein catheter in a term neonate. This case highlights another potentially lethal complication of UVC, and emphasises the risks associated with the procedure. In order for the benefits of UVC to outweigh the risks, certain guidelines are reviewed. The importance of confirming the position of the catheter tip with both anteroposterior and lateral radiographs is emphasised.

Cardiac Tamponade↗

PubMed1997

Sydenham's chorea--analysis of 27 patients and a review of the literature.

The first documented epidemic of Sydenham's chorea was in 1418. In 1686 Thomas Sydenham was the first to describe the condition, but it was Richard Bright who in 1831 first made the association between chorea and rheumatic fever. Chorea is one of the major diagnostic criteria for rheumatic fever. Chorea is often considered a benign self-limiting condition. Little is known about the pathophysiological process. A link between the group A beta-haemolytic streptococcus through an antibody-mediated immune response targeting the basal ganglia has been described. Special investigations have been done to ascertain the pathophysiology, but none is of diagnostic value. The aims of this study were to analyse the clinical findings, the role of special investigations in the management and course of Sydenham's chorea and to review the literature. Data on 27 patients were analysed. Special investigations in these patients can be divided into those necessary to assist in diagnosing acute rheumatic fever and those to exclude other causes that mimic chorea. None of these tests was helpful in diagnosing chorea due to other causes; neither did they influence the management of these patients. In conclusion, Sydenham's chorea remains a clinical diagnosis and extensive and expensive special investigations are seldom warranted.

Adolescent↗

PubMed1996

Congenitally absent pulmonary veins--diagnostic pitfalls. Two case reports.

Two patients with partial absence of the right and left pulmonary veins respectively are described. Congenitally absent pulmonary veins are a rare phenomenon and the diagnosis is often missed or delayed. When children present with haemoptysis and/or recurrent respiratory infections with no obvious underlying cause, absence of the pulmonary veins must be part of the differential diagnosis. Special investigations to be done in these patients are chest roentgenograph to compare the lung volumes, radio-isotope scan, echocardiography and cardiac catheterisation. Magnetic resonance imaging may be helpful in defining the cause and site of obstruction of the pulmonary veins. Depending on the cause, surgery might be considered.

Child↗

PubMed1988

Progressive familial heart block (type I). A follow-up study after 10 years.

A follow-up study was done on 55 patients, all members of families with type I progressive familial heart block (PFHB) examined during 1977. Of the 55 patients 5 had died, 17 had normal ECGs while 7 with previously abnormal ECGs remained unchanged. All the others had progressed to a more severe form of heart block and 8 of them had received permanent pacemakers. These findings again emphasize the importance of regular ECG follow-up examinations of members of PFHB families.

Adolescent↗

PubMed1980

Mucocutaneous lymph node syndrome (Kawasaki disease). A report of 2 cases.

Two cases of Kawasaki disease, both with cardiac involvement, are reported in South African children and the diagnostic problems are discussed. In patient 1 an ECG showed the development of an inferior myocardial infarction, and in patient 2 on aneurysm of the left coronary artery was found at postmortem examination.

Child, Preschool↗

PubMed1977

The need to repeat lumbar puncture.

Four patients with bacterial meningitis are reported. On initial examination 1 patient had a slightly abnormal cerebrospinal fluid (CSF), and in the other 3 patients the CSF was completely normal. An obviously purulent CSF was obtained when lumbar puncture was repeated 14-48 hours later. All 4 patients presented initially with pyrexia, and either neck stiffness or convulsions. In 3 of the 4 patients a cause for pyrexia was found on initial examination but lumbar punctures were done for neck stiffness or convulsions to exclude meningitis. The problems and the need to repeat a lumbar puncture, as well as the importance of blood cultures in a patient with suspected meningitis, are discussed. The fact that a normal specimen of CSF does not exclude meningitis is stressed.

Cerebrospinal Fluid↗

PubMedDate not supplied

Supraventricular tachycardia in children.

The mechanisms causing different supraventricular tachycardias can be identified with the aid of the 12-lead ECG using Tipple's approach. The main aims of this retrospective study were to use the 12-lead ECG to determine the underlying mechanisms of supraventricular arrhythmias and to evaluate the effectiveness of the treatment modalities used. Forty-one patients were included in the study. The main findings were: nine of the 41 patients had atrial tachycardias while junctional tachycardia occurred in 32/41 of our patients. The underlying mechanisms causing the junctional tachycardias were: AVNRT (n = 21), AVRT (n = 10) and JET (n = 1). Of the 10 patients presenting with AVRT, eight were less than one year old. AVNRT occurred more often in the older age group (>1 year of age). Fifteen of the 41 patients had spontaneous cessation of their supraventricular tachycardia. The drug most commonly used during the acute and long-term phases was digoxin. Amiodarone was used in six patients with an 80% success rate. In the early 80s verapamil was used in five patients with a 100% success rate. It is important to note that verapamil is no longer used in children due to its side effects. Lately, adenosine phosphate is the drug of choice in most supraventricular tachycardias. The management of supraventricular tachycardias in paediatric practice is mainly based on clinical studies and individual experience. Care must therefore be taken to choose medication regimens that are likely to be effective with the minimum risk of potentiating abnormal haemodynamics or conduction.

Adolescent↗