Search PubMed⌕ Search

Biomedical subjects

H Franssen

Publications and source records attributed to H Franssen.

At least 73 records · Page 4Linked to original sources
PubMed1994

Temperature dependence of nerve conduction and EMG in neuropathy associated with gammopathy.

The effects of warming on nerve conduction variables and electromyography were studied in 15 patients with a polyneuropathy associated with monoclonal gammopathy of undetermined significance. In each patient median nerve (motor, sensory) and tibial nerve (motor) conduction parameters were measured before and after warming in water at 36 degrees C. Warming: (1) increased the conduction velocity (CV); (2) decreased the distal motor latency, amplitude, and duration of the compound muscle or nerve action potential; and (3) caused fibrillations to appear in 1 patient. The increase in CV with temperature depended upon the CV after warming: the lower this CV, the smaller the increase in CV with temperature (delta CV/delta T). Correction of median nerve motor CV before warming with 2.2 m/s per degree C yielded CV values which were higher than the CV values after warming, because in most patients delta CV/delta T was less than 2.2 m/s per degree C. Because of differences in delta CV/delta T values, it is more accurate to warm the extremity than to correct for temperature.

Aged↗
PubMed1994

Comparison of soybean and pea ENOD40 cDNA clones representing genes expressed during both early and late stages of nodule development.

A pea cDNA clone representing the homologue of the soybean pGmENOD40-1 was isolated and characterized. At the nucleotide level both clones share 55% homology. Strikingly, the homology between the polypeptides derived from the pea and soybean ENOD40 cDNA sequences is only 14%. Despite this low homology Southern analyses revealed that the isolated pea cDNA clone represents the single pea ENOD40. In situ hybridizations showed that at early stages of nodule development and in mature nodules the expression pattern of pea ENOD40 is comparable to that of soybean ENOD40. Although ENOD40 show similar expression patterns in these two nodules, it is questionable whether the putative polypeptides have a similar function, since the homology is very low.

Amino Acid Sequence↗
PubMed1994

Multichannel recording of cerebral potentials evoked by esophageal balloon distension in humans.

In order to obtain insight in the generator localization of esophageal evoked potentials, cerebral responses were recorded from 32 scalp electrodes in five healthy volunteers (two male; three female; age 20-30 years), using series of 50 balloon inflations with 15 ml of air. Sequential topographical mapping of waveforms was performed in each subject. Biphasic waveforms were recorded. At Fpz, a positive deflection at 300 and a negative deflection at 465 msec (P300 and N465) were recorded and at Pz, N300 and P465. At Cz the first peak (N270) was slightly earlier than 300 msec. Waveforms were left to right symmetrical. At distal electrodes, biphasic waveforms were recorded (P300 and N465). In four subjects, a gradual phase shift occurred in between the waveforms at midline electrode Cz and the left and right mastoids. Brain mapping showed phase reversals between central negativity and surrounding positivity at about 300 msec, and between central positivity and surrounding negativity at 400-500 msec. Our data suggest the presence of more than one generator in the anterior and dorsal part of the insula and/or dorsal periinsular cortex.

Adult↗
PubMed1994

Segmental fasciculations as a late sequel of spinal cord injury.

In two patients with a history of spinal cord injury many years ago fasciculations developed in muscles belonging to previously damaged segments. In both patients MRI of the cervical spine showed an area of abnormal signal intensity representing a cavity, near the level of the neurological abnormalities and the cord injury. During a 4-year follow-up period no new neurological or MRI abnormalities were detected. A hypothesis for the genesis of fasciculations following spinal cord injury is presented.

Adult↗
PubMed1994

Polyneuropathy associated with monoclonal gammopathy of undetermined significance. A prospective study of the prognostic value of clinical and laboratory abnormalities.

The natural course of polyneuropathy associated with monoclonal gammopathy of undetermined significance (MGUS) is not well known. We therefore studied 32 untreated patients for a period of 5 years. Fifteen patients had an IgM M-protein, 15 an IgG and two an IgA. There was a male predominance, a mean age of onset at the end of the sixth decade and sensory signs were more pronounced than motor deficits. On entry into the study and during the 5 years of follow-up, we quantified the neuropathy in a standard way: totals of motor and sensory scores; vibration perception threshold; tapping tests; quantified Romberg test; electrophysiological parameters. A significant difference in the natural history between the polyneuropathy associated with IgM-MGUS and IgG/IgA-MGUS was found for the motor and sensory sum scores, the vibration perception threshold and the tapping tests. The polyneuropathy in IgM-MGUS is more progressive, with significantly more weakness and sensory signs, indicating that the neuropathies associated with IgM-MGUS and IgG/A-MGUS may be two different entities. A rapid progression of the neuropathy was found in five patients. We found no predictive factors for this severe progression of the neuropathy of these five patients. Of these five, three (two IgM, one IgG) developed a non-Hodgkin lymphoma.

Electrophysiology↗
PubMed1994

Rhizobium nod factors reactivate the cell cycle during infection and nodule primordium formation, but the cycle is only completed in primordium formation.

Rhizobia induce the formation of root nodules on the roots of leguminous plants. In temperate legumes, nodule organogenesis starts with the induction of cell divisions in regions of the root inner cortex opposite protoxylem poles, resulting in the formation of nodule primordia. It has been postulated that the susceptibility of these inner cortical cells to Rhizobium nodulation (Nod) factors is conferred by an arrest at a specific stage of the cell cycle. Concomitantly with the formation of nodule primordia, cytoplasmic rearrangement occurs in the outer cortex. Radially aligned cytoplasmic strands form bridges, and these have been called preinfection threads. It has been proposed that the cytoplasmic bridges are related to phragmosomes. By studying the in situ expression of the cell cycle genes cyc2, H4, and cdc2 in pea and alfalfa root cortical cells after inoculation with Rhizobium or purified Nod factors, we show that the susceptibility of inner cortical cells to Rhizobium is not conferred by an arrest at the G2 phase and that the majority of the dividing cells are arrested at the G0/G1 phase. Furthermore, the outer cortical cells forming a preinfection thread enter the cell cycle although they do not divide.

Amino Acid Sequence↗
PubMed1994

Chronic idiopathic axonal polyneuropathy: a five year follow up.

Seventy five patients with chronic idiopathic axonal polyneuropathy (CIAP) were studied for five years. The standardised and quantified neurological examination shows that progression of CIAP is slow, and handicap, if present, is not severe. During the follow up period a definite cause of the neuropathy was found in only four patients (two hereditary motor and sensory neuropathy type 2, one sensory chronic inflammatory demyelinating polyneuropathy, one alcoholic neuropathy). At the end of the follow up CIAP was not related to malignancy or gammopathy. Routine repetition of laboratory tests was not informative and these tests should be performed on clinical grounds only.

Aged↗
PubMed1993

Characterization of the soybean early nodulin cDNA clone GmENOD55.

Two cDNA clones of the soybean early nodulin GmENOD55 were characterized. These clones may represent two members of the soybean early nodulin gene family GmENOD55. GmENOD55 has an N-terminal signal peptide and it contains an internal domain consisting of proline and serine residues. Analyses of nodules lacking infection threads and intracellular bacteria suggest that the GmENOD55 gene is first expressed after release of Bradyrhizobium japonicum in plant cells. This conclusion is supported by in situ hybridization studies showing that the expression is restricted to the infected cell type.

Amino Acid Sequence↗
PubMed1993

Characterization of GmENOD40, a gene showing novel patterns of cell-specific expression during soybean nodule development.

In this paper, the soybean 'early nodulin' clone pGmENOD40 is characterized. The GmENOD40 encoded protein does not contain methionine and does not show homology to proteins identified so far. In situ hybridizations showed that this gene has a complex expression pattern during development of determinate soybean nodules. At early stages of development transcription is induced in dividing root cortical cells, the nodule primordium and the pericycle of the root vascular bundle. In mature soybean nodules, the gene is expressed in the uninfected cells of the central tissue and in the pericycle of the nodule vascular bundles. Studies on nodules devoid of intracellular bacteria and infection threads, showed that the expression of the gene in the nodule primordium is induced in these empty nodules, while the induction of the GmENOD40 gene in the nodule vascular bundle requires the presence of intracellular bacteria or infection threads. A pea cDNA clone homologous to GmENOD40 was isolated to enable in situ hybridization studies on indeterminate nodules. The expression patterns in both determinate and indeterminate nodules suggests that the ENOD40 protein might have a transport function.

Amino Acid Sequence↗
PubMed1993

Conserved regulation of the soybean early nodulin ENOD2 gene promoter in determine and indeterminate transgenic root nodules.

The beta-glucuronidase (GUS) activity expressed from the soybean early nodulin ENOD2(B) gene promoter was localized histochemically in nodules of Lotus corniculatus and Trifolium repens. In both the determinate Lotus nodules and the indeterminate Trifolium nodules, activity was found in the parenchyma cells and especially in cells close to the vascular tissue of nodules. The characteristic cell-specific expression of the soybean ENOD2 gene was therefore maintained by the ENOD2(B) promoter in the two developmentally different nodule types. Important DNA elements recognized in transgenic nodules were identified by deletion and hybrid promoter analysis in Lotus corniculatus. An indispensable positive element (PE) and a possible tissue specific element was defined between positions -1792 and -1582 from the transcription start site. Another qualitative control element located between -380 and -53 conferred the ENOD2 characteristic cell type expression on hybrid promoters. This element contains the conserved nodulin gene sequences CTCTT and AAAGAT. In contrast to the ENOD2(B) promoter a chimeric leghemoglobin Ibc3-GUS gene was expressed in the infected cells of both types of nodules. In the indeterminate nodules expression was restricted to the interzone II-III and the active nitrogen-fixing zone III. Interchange of the distal strong positive element (SPE) of Ibc3 and the ENOD2 positive element resulted in an expression pattern different from that observed for the Ibc3 and ENOD2 genes, indicating that different interactions of trans-acting factors are required for regulation of early as well as late nodulin genes.

Base Sequence↗
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

Attenuation of dipoles modelled from SEP due to a lacunar infarct or altered stimulus rate.

In normal subjects and patients with sensory, sensorimotor or motor deficit, due to a unilateral infarct affecting the thalamocortical radiation, SEPs to median nerve stimulation were analyzed by a spatiotemporal dipole model which describes an evoked potential by a limited number of stationary dipoles with time varying amplitudes. In the normal subjects the SEPs were explained by one dipole in the brainstem and two dipoles in the cortical hand area contralateral to stimulation, all with different time courses. Increasing the stimulus rate to 6.2 Hz yielded a reduction of the moment of both cortical dipoles but hardly affected brainstem dipole moment. In the five patients with sensory or sensorimotor deficit the strength of one or both cortical dipoles was reduced on the side of the lesion. In the patients with pure motor deficit cortical dipole activity was normal. The brainstem dipole was preserved in all patients.

Adolescent↗
PubMed1990

The early nodulin transcript ENOD2 is located in the nodule parenchyma (inner cortex) of pea and soybean root nodules.

A pea cDNA clone homologous to the soybean early nodulin clone pGmENOD2 that most probably encodes a cell wall protein was isolated. The derived amino acid sequence of the pea ENOD2 protein shows that it contains the same repeating pentapeptides, ProProHisGluLys and ProProGluTyrGln, as the soybean ENOD2 protein. By in situ hybridization the expression of the ENOD2 gene was shown to occur only in the inner cortex of the indeterminate pea nodule. The transcription of the pea ENOD2 gene starts when the inner cortical cells develop from the nodule meristem. In the determinate soybean nodule the ENOD2 gene is expressed in the inner cortex as well as in cells surrounding the vascular bundle that connects the nodule with the root central cylinder. The term 'nodule inner cortex' is misleading, as there is no direct homology with the root inner cortex. Therefore, we propose to consider this tissue as nodule parenchyma. A possible role of ENOD2 in a major function of the nodule parenchyma, namely creating an oxygen barrier for the central tissue with the Rhizobium containing cells, is discussed.

Amino Acid Sequence↗
PubMed1984

Homologous sequences in non-structural proteins from cowpea mosaic virus and picornaviruses.

Computer analyses have revealed sequence homology between two non-structural proteins encoded by cowpea mosaic virus (CPMV), and corresponding proteins encoded by two picornaviruses, poliovirus and foot-and-mouth disease virus. A region of 535 amino acids in the 87-K polypeptide from CPMV was found to be homologous to the RNA-dependent RNA polymerases from both picornaviruses, the best matches being found where the picornaviral proteins most resemble each other. Additionally, the 58-K polypeptide from CPMV and polypeptide P2-X from poliovirus contain a conserved region of 143 amino acids. Based on the homology observed, a genetic map of the CPMV genome has been constructed in which the 87-K polypeptide represents the core polymerase domain of the CPMV replicase. These results have implications for the evolution of RNA viruses, and mechanisms are discussed which may explain the existence of homology between picornaviruses (animal viruses with single genomic RNAs) and comoviruses (plant viruses with two genomic RNAs).

Journal Article↗
PubMed1984

Evidence That the 32,000-Dalton Protein Encoded by Bottom-Component RNA of Cowpea Mosaic Virus is a Proteolytic Processing Enzyme.

Translation of middle-component RNA of cowpea mosaic virus in vitro produced two polypeptides of 95 and 105 kilodaltons (95K and 105K, respectively) with overlapping amino acid sequences, which were specifically cleaved by a protease encoded by the bottom-component RNA. The proteolytic cleavage was studied by the addition of antibodies raised against various bottom-component RNA-encoded proteins to extracts prepared from bottom-component RNA-inoculated cowpea protoplasts. Since antiserum to the 32K polypeptide efficiently inhibited the proteolytic activity of such extracts, although antiserum to VPg or to the 170K polypeptide did not, evidence was obtained which indicates that the 32K polypeptide represents the protease involved. Fractionation of proteolytically active extract by glycerol gradient centrifugation demonstrated that 32K polypeptides do not exist as free proteins but are aggregated to the bottom-component RNA-encoded 170K, 84K, 60K, or 58K polypeptides. Maximal proteolytic activity was observed for 32K polypeptides associated with 170K polypeptides, suggesting that the activity was unstable and confined to newly synthesized molecules.

Journal Article↗
PubMed1983

Paroxysmal kinesigenic choreoathetosis and abnormal contingent negative variation. A case report.

We treated a patient suffering from paroxysmal kinesigenic choreoathetosis (PKC). The etiology and pathophysiologic mechanism of this rare movement disorder are unclear. Like other patients with PKC, our patient experienced attacks more frequently when making anticipated movements. Because anticipation plays an important role in the genesis of the contingent negative variation (CNV), we investigated the CNV in our patient. One of the components of the CNV, the slow negative wave (SNW), repeatedly showed a remarkable enhancement compared with that of controls. After institution of phenytoin sodium therapy, the attacks of PKC subsided and the SNW amplitude came within the range of control values. There may be a relationship between PKC and the abnormal CNV.

Adolescent↗