Search PubMed⌕ Search

Biomedical subjects

B Falck

Publications and source records attributed to B Falck.

At least 73 records · Page 4Linked to original sources
PubMed1988

Cytomembrane-sandwiching in human epidermal Langerhans cells: a novel reaction to an irritant.

Relatively mild exposure of human epidermis to sodium lauryl sulphate caused a general activation of the Langerhans cell system within 5 hours. An unexpected reactive phenomenon was that this irritant caused some cytomembrane parts to fold upon each other, thereby forming numerous Birbeck granules, several of which had an irregular shape. Spotty cytomembrane damage to the Langerhans cells was also observed.

Administration, Cutaneous↗
PubMed1987

Increased activity of serum gamma-glutamyltransferase in myotonic dystrophy.

The activity of serum gamma-glutamyltransferase (gamma-GT) and its determinants were studied in 17 patients with myotonic dystrophy. The gamma-GT activity was elevated in 11 patients and its mean value was five-fold higher than in healthy controls. The increase in gamma-GT could not be explained by factors generally known to result in a misleading elevation of gamma-GT. Most patients with elevated gamma-GT also had one or more other pathological laboratory tests related to hepatic function but none had a clinically significant liver disease. Serum gamma-GT activity was not related to the disability caused by dystrophy or to the level of serum creatine kinase suggesting that the elevation of serum gamma-GT is not an indication of a general cell membrane dysfunction. It is concluded that the increase in serum gamma-GT activity in patients with myotonic dystrophy is due to a real but mild liver involvement, which should be taken into account in the examination of these patients who often complain of gastrointestinal symptoms.

Adult↗
PubMed1986

Portacaval shunt in the rat: selective alterations in behavior and brain serotonin.

Portacaval shunted (PCS) rats and sham-operated controls were investigated for spontaneous activity, exploration, somatosensory reactivity, swim latencies in a water maze, motor coordination, and passive avoidance 2 to 3 weeks after operation. The rats were subsequently decapitated and indole metabolism was investigated in different brain regions. The results showed that shunted rats were impaired in both open field tests (spontaneous activity and exploration) and in somatosensory reactivity (latency to respond, maximal response and integrated response). Results from motor coordination tasks and learning and memory tests (water maze and passive avoidance) did not demonstrate differences between the groups. There was an increased brain indolamine metabolism in PCS compared to sham-operated rats. No correlation between the behavioral impairment and the altered indolamine metabolism could be demonstrated with multiple correlation analysis.

5-Hydroxytryptophan↗
PubMed1986

Quantitative analysis of individual motor unit potentials: a proposition for standardized terminology and criteria for measurement.

The physiology of the motor unit potential (MUP) is reviewed. The aim is to identify the electrophysiological events in the motor unit that generate the individual parts of the MUP. This is based on insight gained from new experimental techniques, such as single-fiber electromyography (EMG), scanning EMG, and simulation studies of the MUP. A terminology for the different parts of the MUP is also suggested, and nine parameters used to describe different features of the MUP are delineated: duration, spike duration, amplitude, area, spike area, phases, turns, satellites, and variability. Technical aspects, such as electrode type, filtering, and sampling rate of the computers, are discussed as well. In Appendix A, different manual and computer-aided methods for quantitative MUP analysis are described. Despite minor systematic differences between the methods, MUP durations measured by different methods correlate highly with each other (Appendix B). The manual and computer-aided methods have comparable variability between repeated measurements.

Action Potentials↗
PubMed1986

The multifidus muscle in patients with lumbar disc herniation. A histochemical and morphometric analysis of intraoperative biopsies.

Structural changes in the multifidus muscle were analyzed in 41 patients operated on for herniated intervertebral disc. Twelve cadavers served as controls. The two main findings follow: Both in the patients and in the controls the Type 2 muscle fibers were markedly and selectively smaller than the Type 1 fibers, which were of normal size for striated muscles, and the internal structure of Type 1 fibers showed so-called core-targetoid and/or moth-eaten change. Group atrophy or fiber-type grouping (indicators of denervation and reinnervation) were observed only in a few patients. The selective small size of the Type 2 fibers may indicate atrophy due to relative inactivity of the multifidus muscle both in the patients and in the controls, ie, it does not need to be related to the herniated disc. Definite proof for denervation of the multifidus muscle was not observed, but neither the possibility be excluded. The cause of the core-targetoid and/or moth-eaten changes cannot yet be determined with certainty, because these changes are not specific for any single entity but may be due, for example, to denervation, ischemia, or altered use of the muscles because of pain. In any case, because the changes were significantly more common in the patients than in the controls, they signal for a pathologic condition, the character of which remains to be elucidated.

Adult↗
PubMed1986

Familial olivopontocerebellar atrophy with macular degeneration: a separate entity among the olivopontocerebellar atrophies.

A family with hereditary, neuropathologically confirmed olivopontocerebellar atrophy (OPCA) associated with macular degeneration is described. The mode of inheritance was autosomal dominant. The first symptom was insidious, progressive visual loss caused by macular degeneration. Another early sign was slow saccades. Some years after the visual symptoms, gradually progressing cerebellar dysfunction and pyramidal signs developed. Computed tomography of the brain indicated cerebellar and pontine atrophy. Finally the patients were blind, due to a severe chorioretinal atrophy, and disabled because af motor dysfunction. The present study, together with a review of other reported families with OPCA associated with macular degeneration, suggests that this disorder is a specific and clinically recognizable subtype of OPCA.

Adult↗
PubMed1985

Direct evidence for the cytomembrane derivation of Birbeck granules: the membrane-sandwich effect.

Digitonin, which is known to cause extensive damage to cytomembranes in general, was found to have a most remarkable effect on epidermal Langerhans' cells. Thus, it generates a membrane-sandwiching process resulting in the formation of large discs which except for the differences in size have the same morphology as ordinary Birbeck granules. This demonstrates that the cytomembrane of the Langerhans' cell has the inherent ability to superimpose upon itself, leaving little doubt that the normal Birbeck granules derive from the cytomembrane.

Adult↗
PubMed1985

Neuropsychological cognitive performance of patients with type-2 diabetes.

The aim of this study was to assess the cognitive skills and visuo-motor performances of patients with type-2 diabetes. An ADL questionnaire, neurophysiological EEG recordings and a comprehensive battery of neuropsychological tests were administered to 33 type-2 diabetics and to 33 matched controls. Neither neuropsychological nor neurophysiological EEG findings differentiated type-2 diabetics as a group from their controls.

Activities of Daily Living↗
PubMed1984

The ciliated human keratinocyte.

Human keratinocytes were investigated for the presence of single cilia. Almost all basal keratinocytes were found to carry a single cilium in normal, occluded, and psoriatic skin. The ciliary structure was progressively reduced in keratinocytes approaching the surface. No remnants of the ciliary apparatus were found in the granular layer. In one case of nickel-allergic dermatitis (patch test), the keratinocytes had lost their cilia; the significance of this surprising finding remains to be elucidated.

Adult↗
PubMed1984

Sensory conduction velocity of plantar digital nerves in Morton's metatarsalgia.

The orthodromic sensory conduction velocity of the plantar interdigital nerves were measured with needle electrodes in 28 healthy subjects. The stimulating needle electrodes were placed close to the shaft of the proximal phalanx of the toe, and the recording needle electrode was placed behind the medial malleolus. We examined six subjects with clinical symptoms of entrapment of the common plantar digital nerve (Morton's metatarsalgia). Five of the subjects later had surgery. The conduction velocities of the affected interdigital nerves were abnormally slow. The method is technically simple, but more painful than conventional conduction studies.

Adult↗
PubMed1983

Electroluminescent display visual stimulator - a new method for visual evoked potential studies.

A new atomic layer epitaxy electroluminescent display visual stimulator for visual evoked potential studies is described. The display has several advantages over TV monitor stimulators, slide and projector stimulators and LED stimulators. The display is versatile, various patterns, letters or even words may be generated. The display has short rise and decay times, a high and stable luminosity.

Electroencephalography↗
PubMed1983

Fibrillation potentials, positive sharp waves and fasciculation in the intrinsic muscles of the foot in healthy subjects.

The extensor digitorum brevis and abductor digiti minimi muscles were examined bilaterally with electromyography in 53 healthy subjects. In 72% of the subjects either fibrillation potentials, positive sharp waves or fasciculation was seen in at least one muscle examined. These slight, usually symmetric neuropathic signs are believed to be associated with normal aging and to some extent also with external trauma to the nerves and muscles in the distal parts of the foot.

Adolescent↗
PubMed1983

Left-sided carpal tunnel syndrome in butchers.

Butchers from two slaughterhouses were studied for carpal tunnel syndrome. The diagnosis was based on subjective symptoms and electroneurography. In about half of the otherwise healthy butchers there were various degrees of the syndrome in the nondominant hand, or, if the syndrome was bilateral, the nondominant side was more affected. So far two of the subjects have been operated on. The operative findings and results were consistent with carpal tunnel syndrome. The underlying cause for this occupational disorder is probably mechanical stress on the left hand. Various tools are held in the right hand, while the carcass is lifted, torn, and handled with the left hand. The butchers considered the load on the left hand more strenuous than the one on the right. The prolonged heavy grasping with the fingers of the left hand probably leads to thickening of the synovial membrane of the finger flexors within the carpal tunnel. The carpal tunnel is a relatively rigid structure, and an increased diameter of the flexor tendons may cause the carpal tunnel syndrome. This small cluster sample of butchers is not adequate for epidemiologic conclusions. However, carpal tunnel syndrome seems to be an important occupational disorder among butchers.

Abattoirs↗