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Biomedical subjects

F G Jennekens

Publications and source records attributed to F G Jennekens.

At least 55 records · Page 3Linked to original sources
PubMed1993

Intravenous immunoglobulin treatment in patients with chronic inflammatory demyelinating polyneuropathy: a double blind, placebo controlled study.

Patients with a clinical diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) were randomised in a double-blind, placebo-controlled multicentre trial to investigate whether high-dose intravenous immunoglobulin treatment (IVIg) for 5 consecutive days has a beneficial effect. Fifteen patients were randomised to IVIg and 13 to placebo. In the IVIg treatment group 4 patients improved and 3 patients in the placebo group. The degree of improvement of the patients in the IVIg treatment group was no different from the patients in the placebo group. Electrophysiological studies did not show significant differences between the groups. Since a previously performed cross-over trial showed that a selected group of CIDP patients responded better to IVIg than to placebo, it is concluded that we need better criteria to select CIDP patients for treatment with IVIg.

Chronic Disease↗
PubMed1993

Chronic idiopathic polyneuropathy presenting in middle or old age: a clinical and electrophysiological study of 75 patients.

The clinical and electrophysiological features were prospectively studied of 75 patients (46 men and 29 women) with chronic polyneuropathy presenting in middle or old age in whom a diagnosis could not be made even after extensive evaluation and a follow up of six months. The mean age at the onset of symptoms was 56.5 years. The clinical features of chronic idiopathic polyneuropathy are heterogeneous. On clinical grounds 44 patients had a sensorimotor, 29 patients a sensory, and two patients a motor polyneuropathy. The overall clinical course in chronic idiopathic polyneuropathy was slowly progressive. None of the patients became severely disabled. Electrophysiological and nerve biopsy studies were compatible with an axonal polyneuropathy. Antibodies against myelin associated glycoprotein, gangliosides, and sulphatides were assessed in 70 patients and found to be negative.

Age of Onset↗
PubMed1992

Deficiency of acetylcholine receptors in a case of end-plate acetylcholinesterase deficiency: a histochemical investigation.

A young boy is described who, since early infancy, suffered from weakness of predominantly proximal limb muscles. Electromyography revealed impairment of neuromuscular transmission. There were no antibodies against acetylcholine receptors. The amplitude of miniature end-plate potentials was reduced. Neuromuscular junctions showed somewhat coarse postsynaptic junctional folds and degeneration products in the synaptic clefts and in postsynaptic areas. Using qualitative and semiquantitative histochemical methods, at light- and electronmicroscopical levels, acetylcholinesterase (AChE) activity and acetylcholine receptors (AChRs) were demonstrated to be deficient. This patient demonstrates that the clinical picture of congenital myasthenia may closely resemble a congenital myopathy. The findings provide evidence that AChR deficiency offers protection from some of the effects of AChE deficiency. The clinical features of AChE deficiency depend, not only on the level of residual enzyme activity, but also on the degree of AChR reduction, if present.

Acetylcholinesterase↗
PubMed1992

Secondary changes of the motor endplate in Lambert-Eaton myasthenic syndrome: a quantitative study.

Underlying the Lambert-Eaton myasthenic syndrome (LEMS) is a decrease in the release of the neurotransmitter acetylcholine. Only few reports on light and transmission electron microscopical observations of motor endplates in LEMS are available and changes reported so far differ from those found in experimental blocking of acetylcholine release. We performed a quantitative study on intercostal muscle biopsies of five patients. The main light microscopical finding was an enlargement of the area of contact between nerve and muscle, which was interpreted as a compensatory phenomenon. At the ultrastructural level we found the mean postsynaptic area and membrane length of the neuromuscular junctions to be decreased, putatively due to small postsynaptic regions of newly created neuromuscular junctions. The secondary changes in LEMS endplates as seen in this study are similar to those reported in experimental blocking of acetylcholine release.

Aged↗
PubMed1992

Salla disease variant in a Dutch patient. Potential value of polymorphonuclear leucocytes for heterozygote detection.

A Dutch child with psychomotor retardation, impaired speech, ataxia, sialic acid storage and vacuolized skin fibroblasts and lymphocytes was diagnosed as having free sialic acid storage disease. Slight corneal opacities, pale optic disks at the fundus oculi and vertebral abnormalities, not earlier reported in Salla disease, were peculiar to this case. Free sialic acid was about tenfold increased in urine and cultured fibroblasts, without changes in the glycoconjugate-bound sialic acid pool. A subsequent pregnancy of the patient's mother was monitored by assay of sialic acid in chorionic villi and amniotic fluid. An unaffected foetus was predicted. Sialic acid was also assayed in peripheral blood total leucocytes, and in mononuclear and polymorphonuclear (PMN) leucocyte subpopulations. Each of these leucocyte fractions from the patient showed 10- to 30-fold increase in sialic acid content. The PMN subpopulation provided the most restricted range of control values and showed slightly increased values for the patient's parents. These results suggest that the assay of sialic acid in PMN might be useful for the identification of heterozygotes in sialic acid storage disease. Studies on a larger number of obligate heterozygotes are needed to confirm this observation.

Ataxia↗
PubMed1992

Early morphological features in dominantly inherited demyelinating motor and sensory neuropathy (HMSN type I).

Seventeen cases of dominantly inherited demyelinating motor and sensory neuropathy (HMSN type I) with infantile onset were studied. Not only clinical and electrophysiological data, but also the g ratio (axon diameter to fibre diameter), considered to be a distinguishing feature between HMSN type I and HMSN type III, showed overlap. Morphological and morphometrical investigations already revealed a lack of small and large diameter myelinated axons at an early stage, and a demyelinating process most active in early childhood followed later by axonal loss. It was concluded that the histopathology of HMSN type I cannot be sufficiently explained by axonal atrophy with secondary demyelination.

Action Potentials↗
PubMed1992

Medical therapy in spinal muscular atrophy: a realistic expectation?

The hereditary spinal muscular atrophies (SMA) type I-III belong to those diseases for which even the thought of medical therapy seems forbidden. Two neurotrophic factors are, however, now known to exert a markedly stimulating effect on survival of motor neurons in vivo! In principle such factors may become available by recombinant DNA techniques for experiments in animal models of SMA and if these experiments are successful for clinical trials in man. Medical therapy in SMA should aim primarily at patients early in the rapidly progressive phase of their disease, before massive loss of motoneuron has taken place.

Adrenocorticotropic Hormone↗
PubMed1992

ACTH/MSH like peptides in the treatment of cisplatin neuropathy.

The neurological toxicity seen in patients treated with cisplatin in most cases concerns ototoxicity and peripheral neuropathy. Thus far, the pathogenesis of cisplatin neuropathy remains obscure. Yet the fact that cisplatin affects mainly the sensory peripheral nerve fibers points towards an involvement of the dorsal root ganglia. In a rat model of cisplatin neuropathy, following a cumulative dose of approx. 12 mg/kg cisplatin the sensory nerve conduction velocity began to slow as compared to age-matched controls. Peptides derived from ACTH and MSH are known to exert neurotrophic effects. In vivo they facilitate postlesion repair mechanisms in the peripheral nervous system by enhancing the early sprouting response of the damaged nerve. Surprisingly, chronic treatment with a synthetic ACTH4-9 analog not only prevented cisplatin neurotoxicity following a low or high dose regimen, but also counteracted already existing cisplatin-induced neurotoxicity. Stimulated by these findings a randomized, double blind, placebo-controlled study was performed to assess the efficacy of the peptide in the prevention of cisplatin neuropathy in women suffering from ovarian cancer. The threshold of vibration perception (VPT) was used as the principal measure of neurotoxicity. Following 6 cycles of chemotherapy the VPT had increased more than 8-fold in women receiving placebo as co-medication. Whereas the VPT in women receiving 1 mg/m2 body surface ACTH4-9 analog before and after each cisplatin cycle only increased less than 2-fold. No side effects of the peptide treatment were observed and the clinical response to the chemotherapy was similar in all treatment groups. Collectively these preclinical and clinical data suggest that treatment based on non-endocrine fragments of ACTH/MSH may be a therapeutic option in the treatment of cisplatin neuropathy.

Adrenocorticotropic Hormone↗
PubMed1992

Congenital oculo-bulbar palsy.

A girl developed progressive weakness of bulbar and ocular muscles starting before the age of two years. Electromyography revealed a widespread subclinical myopathy. An intercostal muscle biopsy showed complex abnormalities including occasional neurofilamentous accumulations and honeycomb-like membranous material in terminal axons. Endplates were small and some secondary synaptic clefts were abnormally deep. Acetylcholine receptors extended unusually deeply into the clefts of the junctional folds. Muscle fibres showed subsarcolemmal vacuolation at some places. This form of congenital oculo-bulbar palsy does not appear to have been described previously.

Axons↗
PubMed1992

Autosomal recessive form of hereditary motor and sensory neuropathy type I.

We studied pathologic changes in sural nerve biopsies from four patients with probable autosomal recessive (AR) hereditary motor and sensory neuropathy (HMSN) type I with a median motor nerve conduction velocity greater than 10 m/sec, comparing them with the pathologic features in autosomal dominant (AD) HMSN type I. The four recessive and two sporadic cases showed segmental demyelination. However, the classic onion bulbs of concentric Schwann cell processes, which occur in AD type I, were rare; many axons, also of a smaller size, were surrounded by onion bulbs of basal laminae. Schwann cells of the myelinated and unmyelinated types were involved in these onion bulb formations. Patients with HMSN type I who have many basal lamina onion bulbs should be considered as having AR inheritance.

Adolescent↗
PubMed1992

Neurological examination of patients suffering from leprosy: is it worthwhile?

We examined 28 male leprosy patients to discover if a more extensive neurological investigation than usual would be worthwhile in diagnosis and/or management. Our findings were fully compatible with what might be expected from a mononeuritis multiplex, either due to leprosy or other causes. The following observations are noteworthy. Changes of position sense and a decrease of some tendon reflexes were present in a minority of the patients. In soles of the feet, considered to be an- or hypaesthetic, some residual pain sensation could occasionally be detected. Functional testing of at least one muscle group (m. triceps surae) appeared to be more reliable than manual testing according to MRC criteria. We concluded that an extensive neurological examination is probably not required for diagnosis. It does provide, however, more accurate information on the extent of damage to the peripheral nervous system, which may be important for management and for assessment of treatment effects. The use of a myometer is advocated.

Adult↗
PubMed1991

A non-immunogenic myasthenia gravis model and its application in a study of transsynaptic regulation at the neuromuscular junction.

A non-immunological model for myasthenia gravis was developed in rats: 'toxin-induced myasthenia gravis'. Rats were injected once every 48 h with 3-5 micrograms alpha-bungarotoxin for periods of up to 5 weeks. This treatment caused weakness, especially of facial muscles. Respiration, however, was unaffected. Miniature endplate potentials and 125I-alpha-bungarotoxin binding in the extensor digitorum longus muscles were severely reduced. Acetylcholine release evoked by electrical and chemical (50 mM KCl) stimulation was higher in diaphragms from alpha-bungarotoxin-treated rats than in those from control animals. Histological investigation of the tibialis anterior muscle provided no evidence that the endplates were enlarged. It is concluded that the activity of acetylcholine receptors influences the rate of transmitter release in the neuromuscular junction and it is suggested that a transsynaptic regulation process may be active in myasthenia gravis. The present animal model for myasthenia gravis seems very suitable for studying such a regulation of transmitter release.

Acetylcholine↗
PubMed1991

Nerve growth factor receptor immunostaining in the spinal cord and peripheral nerves in amyotrophic lateral sclerosis.

In animal experiments, nerve transection is followed by expression of nerve growth factor receptors (NGFR) on Schwann cells of both motor and sensory nerve fibres distally to the site of the lesion. To determine whether denervated Schwann cells in amyotrophic lateral sclerosis (ALS) similarly express NGFR, a study was made of post-mortem material of peripheral nerves and ventral roots from ALS cases and age-matched controls, using immunolabelling methods. Dorsal roots and spinal cords were also examined for the presence of NGFR. In all the ALS cases and controls, NGFR immunostaining was seen in the outer layer of vessel walls, perineurial sheaths, connective tissue surrounding fascicles in nerve roots and in the substantia gelatinosa of the spinal cord. In ALS, NGFR staining was also present in the Schwann cells of degenerated nerve fibres in mixed peripheral nerves, in ventral roots and, to a lesser extent, in dorsal roots. NGFR immunoreactivity was also seen in elongated cells extending from the perifascicular connective tissue into the nerve fascicles. It is concluded that denervated Schwann cells in ALS express NGFR and that NGFR immunostaining on Schwann cells may be used as an indicator of axonal degeneration. The NGFR labelling in the dorsal roots supports the notion that ALS is not a pure motor syndrome.

Amyotrophic Lateral Sclerosis↗
PubMed1991

Hereditary motor and sensory neuropathy of neuronal type with onset in early childhood.

Eighteen cases of a chronic progressive motor and sensory neuropathy of neuronal type with early onset are described. Based on the presented data and literature reports a condition is distinguished, which is in clinical, genetic and morphological aspects different from autosomal dominant HMSN type II. The condition corresponds to that described by Ouvrier et al. (1981). It shows a congenital or early childhood onset and causes a severe disability usually with wheelchair dependency already in puberty or later in adult life. The condition is probably transmitted by an autosomal recessive gene. Morphological features of biopsied nerves are an extensive loss of large diameter fibres with a shift to smaller diameters in the histogram. Regenerative features are almost absent in contrast to the distinct cluster formation in autosomal dominant HMSN type II. A maturation disturbance of peripheral motor and sensory neurons with a concomitant or secondary process of chronic neuronal degeneration is suggested. One dominantly inherited case in our group with an infantile onset exhibits clinical and morphological features consistent with an autosomal dominant HMSN type II.

Electrophysiology↗
PubMed1991

Lip-length and snout indices in Bell's palsy. A comparison with the House grading system.

The lip-length (LL) and snout (S) indices provide information on peri-oral muscular function. They were determined in 18 patients suffering from Bell's palsy and compared with the results obtained by scoring according to the House grading system. A high correlation was found. LL and S indices are continuous variables, which facilitates their statistical evaluation. Results of the House scoring system are given in an ordinal scale and reflect overall facial muscular function. It is concluded that the indices and the House scoring system produce a different kind of information, but they are complementary to each other in the assessment of facial muscular function.

Facial Muscles↗