Search PubMed⌕ Search

Biomedical subjects

M Lammens

Publications and source records attributed to M Lammens.

At least 55 records · Page 3Linked to original sources
PubMed1996

Clinical and molecular genetic features of congenital spinal muscular atrophy.

A neonate presented with the fetal hypokinesia sequence and signs of spinal muscular atrophy (SMA). Severe pathological changes including ballooned neurons and neuronophagia were found not only in the motor nerve nuclei but also in the thalamic, cerebellar, and brainstem nuclei as well as in the dorsal root ganglia. Direct DNA analysis showed the presence of a chimeric SMN gene, with a rearrangement occurring between exon 7 of the centromeric SMN gene and exon 8 of the telomeric SMN gene. Circumstantial evidence suggests that only a single copy of this gene is present, with transcriptional characteristics of a centromeric SMN gene. In addition, a homozygous deletion in the NAIP genes was demonstrated. This observation demonstrates that at least some cases with fetal hypokinesia and SMA may represent the severe end of a spectrum of disorders caused by deletions in the SMA locus on chromosome 5q13. In addition, these findings are compatible with a modifying role for the centromeric SMN genes and the NAIP genes in the severity of the SMA phenotype.

Autoantigens↗
PubMed1996

Anaplastic (malignant) ganglioglioma arising from heterotopic grey matter nodules.

Anaplastic ganglioglioma is a rare malignant neoplasm. The short clinical course and the anaplastic histological features are characteristics of malignant ganglioglioma. Immunohistochemistry is necessary for the final diagnosis. The MRI appearances are described here for the first time in literature. Nodular grey matter heterotopias had been demonstrated and the patient developed an anaplastic ganglioglioma two years later, on the same place where the grey matter heteropias had been seen. This finding supports the hypothesis that these tumours may arise from grey matter nodules.

Adult↗
PubMed1996

Pathological findings in a patient with amyotrophic lateral sclerosis and multifocal motor neuropathy with conduction block.

We studied a 53-year-old woman with progressive weakness of the left arm, gradually spreading to the other limbs. Neurological examination revealed a motor neuron syndrome with paresis, fasciculations and atrophy. Electrophysiological studies showed multiple motor conduction blocks. The anti-GM1 IgM titer was elevated. The patient was thought to have a multifocal motor neuropathy. Despite intravenous cyclophosphamide treatment, however, she died with respiratory insufficiency. On postmortem examination, the brachial plexus showed patches of demyelination underlying different areas of motor conduction block. The spinal cord, however, revealed severe neuronal loss in the ventral horn and axonal loss in the corticospinal tract, indicative of amyotrophic lateral sclerosis. Demyelination of peripheral nerves could have been responsible for the other conduction blocks in this patient. The prominent degeneration of motor neurons, however, must also have played a role in the clinical picture. Some patients with the syndrome of a multifocal motor neuropathy may have MND rather than, or in addition to, a demyelinating peripheral motor neuropathy.

Action Potentials↗
PubMed1996

Detection of Toxoplasma gondii tachyzoites and bradyzoites in blood, urine, and brains of infected mice.

Different techniques for identifying Toxoplasma gondii were compared. PCR was used to amplify part of the major surface antigen P30 gene of T. gondii. Amplified-DNA detection with the DNA enzyme immunoassay (PCR-DEIA) was more sensitive than ethidium bromide staining after agarose gel electrophoresis and as sensitive as nested PCR. PCR-DEIA, using common enzyme-linked immunosorbent assay (ELISA) methods, avoids agarose gel electrophoresis for the identification of amplified products. T. gondii can also be detected with equal sensitivity in infected fibroblasts, but only after at least 8 days of cell culture. PCR-DEIA is thus recommended because of its sensitivity and convenience for detecting early parasitemia in the surveillance of toxoplasmosis among pregnant women and immunocompromised hosts. The courses of infection in mice infected with two strains of T. gondii were compared. Tachyzoites of the virulent strain T. gondii RH, killing the host in 4 days, were identified in urine specimens and blood samples of mice 24 to 94 h after inoculation but not in brains, but no antibodies were detected. After intraperitoneal inoculation with cysts of the low-level virulence Beverley strain of T. gondii, parasites were identified in blood samples 4 days later and up to 17 days (but not in urine specimens) and in the brain from day 6 through day 525. By ELISA, high antibody titers were found from day 11 to day 525, with parasitemia preceding the appearance of antibodies. The usefulness of PCR-DEIA tests in conjunction with the search for circulating antibodies for the early diagnosis of toxoplasmosis in humans is discussed.

Animals↗
PubMed1996

Aggressive pituitary macroadenoma: CT and MR appearances.

Two cases of aggressive pituitary macroadenoma (prolactinoma) with diffuse invasion of the skull base are described. Clinical signs usually appear late. CT shows the bone destruction, whereas MRI accurately delineates the extension of the tumor and involvement of the surrounding neurovascular structures. Histopathology and immunohistochemical staining are necessary for a definitive diagnosis differentiating prolactimonas from a wide range of skull base tumours and for deciding on additional therapy and prognosis. Aggressive pituitary macroadenoma is a large and diffuse tumor which is difficult to treat; therapy usually consists of extensive surgery, radiotherapy and pharmacotherapy with dopaminergic agents.

Adult↗
PubMed1995

Neurovascular intact muscle transposition for anal sphincter repair. Experimental model and experience with dynamic pacing.

PURPOSE: To study muscle behavior for anal sphincter repair, radiologic, manometric, and histologic techniques in a dog animal model have been used. Special attention was given to the problem of resting length of the transposed muscle. METHODS: The semitendinosus muscle of the dog could be transposed successfully to create a new anal sphincter based on an intact neurovascular pedicle. The parallel-fibered muscle was split at its distal end and encircled around the anal canal. Manometry was performed intraoperatively and postoperatively. A sufficiency high basal and squeeze pressure had to be obtained intraoperatively to guarantee a final continent neosphincter. This could be realized by a progressive stretching of the muscle until maximum squeeze is reached. In one animal a pacemaker was implanted, and postoperatively a fixed sphincter stimulation protocol was started. Muscle biopsies of the normal anal sphincter and the neosphincter were taken. RESULTS: 1) Muscle transposition gave a high degree of continence in this experimental model, with a mean resting pressure of +/- 40 mmHg and a mean squeezing pressure of +/- 73 mmHg. 2) Electric stimulation of the neosphincter in one animal influenced the resting pressure but not the squeeze pressure. 3) Muscle fiber type composition changed toward a slow fiber type composition after transposition of the fast muscle and even more after stimulation. CONCLUSIONS: 1) Creation of a muscle cuff around the anal sphincter can substitute normal anal sphincter. 2) Adequate stretch of muscle fibers is essential for continence. 3) Electrical pacing helps preserve resting tension and subsequent continence.

Anal Canal↗
PubMed1995

Fetal akinesia sequence caused by glycogenosis type VII.

We report on the autopsy study of a premature boy with multiple joint contractures who died soon after birth of severe lung hypoplasia. Muscle histology showed PAS-positive vacuoles, and electronmicroscopy revealed massive subsarcolemmal and intermyofibrillar accumulation of glycogen. Biochemical analysis of fresh-frozen muscle tissue disclosed increased glycogen content and a complete lack of phosphofructokinase (PFK) activity. The brain showed focal cerebral and diffuse cerebellar white matter gliosis, and patchy loss of internal granular and Purkinje cells in the cerebellar cortex. The spinal cord was normal. This report describes the first case of PFK deficiency, presenting as a lethal fetal akinesia sequence.

Abnormalities, Multiple↗
PubMed1994

Deletion in the CMT1A locus on chromosome 17p11.2 in hereditary neuropathy with liability to pressure palsies.

Hereditary neuropathy with liability to pressure palsies (NHPP) is an autosomal dominant disease of peripheral nerves, characterized by recurrent focal neuropathies often with an underlying asymptomatic polyneuropathy. We report the clinical, electrophysiological, and histopathological findings in three families with HNPP and confirm the presence of a deletion on chromosome 17p11.2, including all the markers known to be duplicated in Charcot-Marie-Tooth disease type 1A. This deletion appears to be the underlying molecular deficit in this disease and provides additional evidence for the importance of this locus for peripheral nerve function.

Adolescent↗
PubMed1994

Pure autonomic failure: a new case with clinical, biochemical, and necropsy data.

Postmortem examination of a patient with pure autonomic failure showed loss of intermediolateral column cells and of sympathetic ganglionic neurons; there were Lewy bodies in sympathetic neurons. No neuronal loss or Lewy bodies were seen in pigmented brainstem nuclei. This case indicates that pure autonomic failure can occur in the absence of presymptomatic Parkinson's disease. Furthermore, it supports the view that in pure autonomic failure the lesion is more distal than in autonomic failure associated with multiple system atrophy.

Autonomic Nervous System Diseases↗
PubMed1992

Further evidence for myelinated as well as unmyelinated fibre damage in a rat model of neuropathic pain.

A mononeuropathy, produced by ligation of the sciatic nerve in rats, has recently been proposed as an animal model of experimental pain and pain-related disorders (hyperalgesia and allodynia). We investigated quantitatively the morphological changes in myelinated and unmyelinated fibres of the sciatic nerves 2 weeks after ligation in rats exhibiting allodynia to thermal stimulation. There was a marked reduction in the number of large myelinated fibres distal to the ligature (711 +/- 34 compared with 5315 +/- 230 in normal nerves). We also found a significant loss of small myelinated fibres (2429 +/- 109 compared with 3197 +/- 308 in normal nerves), the remaining fibres of this type showing pathological properties. Finally, ultrastructural evidence of damage to unmyelinated fibres was found. The typical pattern of large clusters of normal unmyelinated axons was no longer present within most regions of the nerve. There was a significant reduction in the size of the unmyelinated fibres (0.41 micron +/- 0.15 compared with 0.71 micron +/- 0.08 in normal nerves), together with a twofold increase in their number per cluster. Hypotheses about the mechanism of thermal allodynia in this pain model therefore must take into account the fact that all fibre classes show pathological changes.

Animals↗
PubMed1992

Purulent meningitis due to aspergillosis in a patient with systemic lupus erythematosus.

We report a 39-year-old female patient with systemic lupus erythematosus under immunosuppressive therapy who developed persistent neutrophilic meningitis, for which no infectious agent could be identified. Intensifying the immunosuppressive therapy induced a short amelioration of the clinical picture. At autopsy, basal meningitis was found to be due to Aspergillus sp.

Adult↗
PubMed1992

Ethanol-induced disturbances of gliogenesis and neuronogenesis in the developing murine brain: an in vitro and in vivo immunohistochemical and ultrastructural study.

The effects of ethanol on murine brain development were studied in a model of whole embryo culture and in vivo. Ethanol locally enhances cell death in the primitive neuroepithelium. During neuronal migration, ethanol induces a premature transformation of the radial glial guides into astrocytes. Ethanol also inhibits the late gliogenesis. The resulting postmigratory neocortex displays an abnormal neuronal pattern almost completely deprived of vertical columnization. These glial-neuronal disturbances can explain neuropathological and clinical features of the fetal alcohol syndrome. Our study provides also an experimental tool for the study of cell death in normal and abnormal conditions at early stages of neurogenesis.

Animals↗
PubMed1992

MR imaging of intracranial aspergilloma extending from the sphenoid sinus in an immunocompromised patient with multiple myeloma.

A case of fatal intracranial aspergillosis, extending from the sphenoid sinus via the orbit into the subarachnoid space of the optochiasmatic cistern and the cistern of the middle cerebral artery is presented in an immunosuppressed patient with multiple myeloma. Adequate treatment was not instituted and the patient died because the condition was not recognised and interpreted as a soft tissue extension of an orbital localization of myeloma. MRI, especially after intravenous injection of Gadolinium, depicted very accurately the extension of the disease, as defined at autopsy.

Aspergillosis↗
PubMed1991

Extradural epidermoid tumor of the frontal bone.

The radiologic findings in a case of an extradural diploic epidermoid tumor (ET) of the frontal bone, examined with plain X rays, CT and MRI, are reported. A head injury with traumatic inclusion of epidermis could have been the origin of the tumor. This report stresses the importance of the plain skull X ray in the diagnosis of extradural ET.

Adult↗
PubMed1991

Paralysis of saccades and pursuit: clinicopathologic study.

We report a 73-year-old patient with an eye movement disorder characterized by paralysis of saccades and pursuit. At autopsy, there were small cortical lesions in the middle frontal gyrus immediately anterior to the precentral gyrus and in the inferior parietal lobule on both sides.

Aged↗
PubMed1991

Globoid cell leukodystrophy: a family with both late-infantile and adult type.

We present a patient with adult-onset globoid cell leukodystrophy (GBL) who had almost complete deficiency of galactosylceramide beta-galactosidase. A brother of the index patient deteriorated neurologically and died at the age of 4, probably from the late-infantile form of the disease. In this family, two clinical types of GBL are probably different expressions of an identical genotype.

Adult↗