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Biomedical subjects

F Lange

Publications and source records attributed to F Lange.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Problems of muscular fatigue--relationship to stimulation conduction velocity and K(+) concentration].

Muscle fatigue is accompanied by a series of biochemical correlations as substrate depletion, lactate accumulation, shifts of pH, increase of phosphate (Pi), arise of free radicals or disturbances of ionic balances. In last time high interest has been directed to the increase of extracellular potassium during extensive muscle activity. It was suggested that high K+ concentration in the interstitium may alter propagation of action potential along the T-tubules or induces membrane depolarization with physiological consequences. In order to elucidate the role of potassium accumulation, experiments were performed on isolated rat muscles. An elevation from 5 to 10 mmol K+ of the bath solution causes a significant decrease of the conduction velocity of the action potential. This effect is more pronounced on fatigue-sensitive fast twitch EDL muscles than on fatigue-resistant slow twitch SOL muscles. Moreover, after tetanic stimulations of these muscles in normal solution, the conduction velocity dropped by the same amount as in high K+ solution but, again, differently in both muscle types. Therefore it is supposed that K+ accumulation during intensive muscle activity contributes to fatigue.

Animals↗
PubMed1989

Tetracycline and erythromycin distribution in pathological lungs of humans and rat.

Tetracycline and erythromycin concentrate highly in pulmonary tissues in humans as well as in the rat. Their binding to the lung, whatever the species and the pathological state, is weak. Their intrapulmonary concentrations could be explained by a passive diffusion which depends on the pH variation between the intra- and extratissue compartments, the percentage of un-ionized form present, and their liposolubility. The importance of retention of tetracycline and erythromycin by plasma proteins is demonstrated by the decrease of their pulmonary index of penetration (IP, the intra- and extratissue concentrations ratio). The IP values are, respectively, 1.09 and 1.23 for tetracycline and erythromycin. These concentrations are in excess of their minimal inhibitory concentrations for bacteria responsible for pneumopathies. The lung homogenate binding of these antibiotics is weak (5% for erythromycin and 33% for tetracycline), corresponding to a nonsaturable binding to three main subcellular fractions (nucleus, mitochondria, and cytosol). Tetracycline has the same penetration in healthy or cancerous human lungs, whereas erythromycin presents a decreased IP in cancerous tissue. However, the binding of these antibiotics to healthy or cancerous lung homogenates is similar. So, the structure of cancerous cells is solely responsible for this modification of erythromycin penetration. The intrapulmonary concentration of tetracycline is increased in rat lungs infected by Legionella pneumophila. This modification is due to a great bacteria retention. In contrast, erythromycin possesses the same IP in healthy and infected rat lungs.

Animals↗
PubMed1989

[Functional and morphological identification of FSH- and LH-producing cells in the pituitary gland].

The identification of pituitary FSH and LH cells in states of pharmacological treatment influencing the pituitary FSH and LH production was performed by histological staining at the isoelectric points of these hormones in the cat. The intensity of the stained material in the hormone-producing cells was determined by a microphotometric technique. As a physiological control, the FSH and LH levels in blood were measured by a radioimmunoassay.

Animals↗
PubMed1989

Changes of the conduction velocity of isolated muscles induced by altered external potassium concentration.

The propagation of action potentials along fibre bundles of fast and slow twitch rat muscles was tested by means of two separated different electrodes. In spite of marked differences in contractile properties between fast and slow twitch bundles, the conduction velocity (c.v.) was found to be similar in all preparations at room temperature. At 35 degrees C the c.v. was 2.76 +/- 0.36 m.s-1 in SOL and 3.0 +/- 0.77 m.s-1 in EDL muscles, respectively. An elevation of the extracellular K+ from 5 to 10 mM caused a reduction of the c.v. by 20 - 40% in limb and sternomastoid muscles. The effect increased with higher K+ concentrations. Repeated tetanic stimulation also induced a decrease of the c.v. The opposite effect occurred in solution with reduced external K+. In O K+ solution the c.v. of fast twitch fibres increased by almost 50%. The results show that extracellular K+ interacts with processes of the regeneration of the action potential along the fibres.

Animals↗
PubMed1988

Pathological findings in three non-Japanese patients with the POEMS syndrome.

The pathological features of three European patients with plasma cell dyscrasia, osteosclerosis and a multisystem disorder, most frequent in Japan, that includes polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes (POEMS syndrome), are reported. The material was obtained from biopsies (peroneal nerve, lymph node) and general autopsy, including hypophysis, in one case. The most salient findings were: peripheral nerve lesions, including both segmental demyelination and axonal degeneration, with so-called uncompacted myelin lamellae (UML); angiofollicular lymph node hyperplasia (AFLNH); and non inflammatory vascular changes. Though not specific, it appears that UML and AFLNH may be contributive findings in atypical cases of POEMS syndrome (incomplete forms, lack of underlying malignant plasma cell dyscrasia or circulating monoclonal immunoglobulin). Among the various autopsy findings we emphasize the skin thickening which was secondary to a hyaline sclerosis of the papillary dermis, and the presence in adenohypophysis of numerous cells showing positive reactions with the anti-alpha MSH antibody. Though immunological, vascular and hormonal disturbances have been implicated at the origin of several manifestations of the disorder, the pathogenesis of the POEMS syndrome remains obscure.

Adult↗
PubMed1987

Effect of low-level NO2 chronic exposure on elastase-induced emphysema.

The effect of chronic exposure to 2 ppm nitrogen dioxide (NO2) for 8 hr a day, 5 days a week, for 8 weeks was assessed in normal and emphysematous hamsters by measuring (1) lung morphometry (mean linear intercept [Lm] and internal surface area [ISA]), (2) lung mechanics (lung volume, compliance and coefficient of static deflation, pressure-volume curve fitted to an exponential equation), and (3) serum elastolytic activity and protease inhibitor capacity. Emphysema was induced by a single intratracheal injection of 6 IU porcine pancreatic elastase. Four groups of animals were used; Control, NO2-exposed, elastase-treated, and NO2-exposed postelastase. Our results show that NO2 exposure alone induced mild emphysematous lesions whose degree of severity estimated by morphometry increase in Lm and decrease in ISA. P less than 0.01) was of the same order as that of the lesions induced by 6 IU elastase. Exposure to 2 ppm NO2 enhanced elastase-induced emphysema (further increased Lm and further reduced ISA. P less than 0.01). By contrast, study of lung mechanics revealed no difference between the control and NO2-exposed groups or between the elastase-treated animals exposed to NO2 and those not so exposed. This apparent discrepancy between results of morphometry and lung mechanics may be due to the lower sensitivity of lung mechanics parameters and their consequent inability to reflect changes in the emphysematous lesions induced by elastase injection or 2 ppm NO2 inhalation. In vivo, serum elastolytic activity and protease inhibitor capacity were not modified in any group, indicating that either serum does not reflect the degree of protease inhibitor capacity in the alveolar spaces or chronic inhalation of low concentrations of NO2 is not sufficient to cause elastase/antielastase imbalance. Lastly, our results suggest that chronic exposure to 2 ppm NO2 may cause individuals with inherited or acquired emphysematous lesions to develop more severe emphysema.

Animals↗
PubMed1987

Alterations of beta-adrenergic, muscarinic cholinergic receptors and imipramine binding sites in human lung tumors.

Direct ligand binding techniques have been used to compare beta-adrenergic receptors, muscarinic cholinergic receptors and imipramine binding sites in human tumoral and healthy lungs removed from eleven patients during operations. Beta-adrenergic and muscarinic cholinergic receptors are present in tumoral tissues but their concentrations were decreased compared to healthy tissues. Imipramine binding sites were absent. It is concluded that this type of studies could bring additional information to morbid anatomy analysis and be used to follow illness evolution.

Adenocarcinoma↗
PubMed1987

Isometric twitch and tetanic contraction of frog skeletal muscles at temperatures between 0 to 30 degrees C.

Maximum twitch and tetanic tension development, time to peak, and half relaxation time were studied on isolated frog sartorius muscles stimulated directly in Ringer's solution at different temperatures. Cooling from 20 degrees C to 10 degrees C decreased the tetanic tension (Q10 = 1.3-1.4). At temperatures above 25 (30) degrees C the tension output was reduced. The response to cooling of the twitch contraction was a prolongation of the time to peak (Q10 = 2.4) and of the relaxation time (Q10 = 2.7) independently of the amplitude which increased in most muscles. Between 20 and 10 degrees C the tension output rose by a factor of 1.2-1.3. The failure of this response showed no relation to season. The increase of the twitch tension but the decrease of tetanic tension in parallel with the temperature drop shifted the ratio twitch/tetanus to higher values (0.5 to 0.8). The results suggest that cooling effects both the Ca2+ release and and the Ca2+ re-uptake but the latter one with a higher Q10. This causes a prolongation of the active state and a cold potentiation if further facilitating conditions are present. In contrast, the response to temperature of the tetanic tension seems to be due to the temperature dependent force generation per cross-bridge.

Animals↗
PubMed1986

Studies on the serology of flagellar antigens of Yersinia enterocolitica and related Yersinia species.

A total of 1242 strains of Y. enterocolitica, 104 strains of Y. frederiksenii, 95 strains of Y. kristensenii and 85 strains of Y. intermedia were serotyped with antisera against 56 O antigens and 19 H antigens according to the extended antigenic scheme of Wauters, and with additional antisera against 4 somatic and 19 flagellar antigens not previously described. H antigens of Y. frederiksenii, Y. kristensenii, and Y. intermedia turned out to be rather homogeneous without distinct subfactors. In these species the scope of identified serovars was narrow. Flagellar antigens of Y. enterocolitica were mostly composed of several subfactors, leading to a total of 117 serovars identified in the species. A number of cross-reactions between Yersinia H antigens were observed which could be avoided by absorption without significant lowering of the titre. Flagellar antigens of Yersinia were monophasic, and species specific. The antigens remained stable after storage in agar stabs and repeated subcultures. The epidemiological value of serotyping is demonstrated by strains from three different sources. It is suggested serotyping of Yersinia strains should be performed in three steps: O typing of the prevailing enteropathogenic Y. enterocolitica serogroups in the medical routine laboratory; O and H typing of Y. enterocolitica by National Reference Centres applying a typing scheme reduced to this species; and O and H typing of Y. enterocolitica, Y. frederiksenii, Y. kristensenii and Y. intermedia by specialized International Centres using an extended typing scheme. The need for international standards comparable to those established for Salmonella is emphasized.

Animals↗
PubMed1986

Major and modified nucleosides as markers in ovarian cancer: a pilot study.

A number of major and modified nucleosides were measured in urine samples of patients with ovarian cancer. The patients were divided into three groups based on histological criteria: benign, borderline, malignant. 44% of the measured marker levels of the benign group were in the normal range, whereas 97% of the borderline and malignant groups were outside the normal range. After a total hysterectomy with adnexectomy and omentectomy in a patient with a borderline type malignancy, six of the seven elevated markers decreased to normal values.

Adult↗
PubMed1986

Ion microscopy of the thyroid gland: a method for imaging stable and radioactive iodine.

Analytical ion microscopy has been applied to the study of distribution of stable and radioactive iodine in the thyroid gland. Analytical images, each of them representing the distribution of one isotope of iodine, can easily be obtained in a few seconds from an Epon section with a resolution of 0.5 micron. In thyroids of normal rats, intrafollicular and intracytoplasmic stable 127I can be clearly distinguished. After thyreostimulin injection, a rapid and important redistribution of 127I is observed which reflects an intense cytoplasmic reabsorption of intrafollicular iodine. After injection of a long-lived isotope of iodine, 129I, the progressive incorporation of this isotope has been observed and the images of the natural iodine 129I have been compared to the images of 127I. An unusual iodine distribution has been observed in proliferating cells of an autonomous nodule. The very high sensitivity of this method makes possible the study of intracellular and extracellular stable iodine in the thyroid gland in a number of physiological and pathological conditions; its ability for isotopic analysis in microscopic volumes offers new possibilities for kinetic studies of iodine metabolism. However, in the present state of the art the specimen cannot be studied at the ultrastructural level as it is with other methods, and some difficulties remain in qualitative analysis such as the contamination of spectra with organic mass fragments which makes difficult the study of some elements such as sulfur. In addition, the matrix effect on ionization efficiency or on sputtering rate makes quantitative analysis difficult. In the future, image processing systems will be needed for a better quantitative interpretation.

Adenoma↗
PubMed1986

[Acute ischemia of the extremities and drug addiction].

It is not unusual to find ischemia of limbs in drug addicts and two new cases are reported, together with a literature review, allowing analysis of physiopathologic mechanisms and therapeutic modalities. The first case was a 20 year old man who presented with sensory-motor ischemia of the right hand after injection of heroin into the radial artery. Arteriography showed partial occlusion of the deep palmar arch and all collateral arteries of fingers. Regression of ischemia followed administration of thrombolytics, heparin and vasodilators, arteriography showing restoration of palmar arch and digital arteries flow apart from that of the 4th finger. The latter developed distal necrosis which required, in spite of thoracic sympathectomy, amputation of the 3rd phalanx. Histology of amputation piece showed presence of intra-arterial foreign bodies. The second case was a 30 year old man who presented with an acute sensory-motor ischemia of left calf and foot after injection of heroin into the retromalleolar groove. Arteriography showed absence of opacification of vascular axes in the middle third of leg and an atheromatous plaque in left main iliac artery. Heparin therapy plus lumbar sympathectomy resulted in reheating of the foot, but ischemia recurred one month later. A repeat arteriography with oblique images demonstrated that the plaque in the main iliac artery was larger than it appeared in frontal images and that an embolus had developed in the deep femoral artery. Final treatment in this patient involved an inter-femoral saphenous vein bypass and amputation of 4th toe. Histology of amputation piece showed only a banal arterial thrombosis without foreign body.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

[Nonatheromatous degenerative aneurysm of the popliteal artery in a young adult female].

A degenerative non atheromatous popliteal aneurysm was observed in a 32 year old woman. At microscopical examination of the aneurysmal shell, the internal elastic-lamina and the muscular fibers of the media appeared to be replaced by a thick acellular collagen layer. No other arterial abnormality was found on a complete arteriography and the etiological screening failed. Therefore the aneurysm was classified as an arterial dysplasia. As far as we know, only two similar cases were previously reported in the literature. The true nature of these lesions remain unknown.

Adult↗
PubMed1985

[Acute adult respiratory distress syndrome after lymphography].

Pulmonary complications of lymphography are usually described as radiological infiltrates without clinical symptoms. However, a case is here reported of an adult respiratory distress syndrome occurring after lymphography in a 60 year old female lymphoma patient. Pulmonary oedema developed within 48 h; haemodynamic study showed a normal capillary wedge pressure. The patient died from intractable low cardiac output within 24 h. Post-mortem examination showed pulmonary lymphocytic infiltration and multiple fat emboli. The lack of lymphatic drainage was probably responsible for the intravascular passage of lipid-soluble contrast medium, this giving endothelial lesions. In such patients with preexisting lung disease or pulmonary involvement in haematological disease, lymphography has to be considered carefully.

Embolism, Fat↗
PubMed1985

Biosynthesis of hyaluronic acid, heparan sulfate and structural glycoproteins in hamster lung explants during elastase induced emphysema.

Hyaluronic acid (HA), heparan sulfate (HS) and structural glycoproteins (SGP) were investigated in explant cultures of hamster lungs by studying incorporation of 14C-glucosamine (14C GlcN) on the first and on the 24th day after intratracheal administration of pancreatic elastase. The different 14C radiolabeled macromolecules were extracted sequentially by 0.4 M guanidinium chloride (0.4 M GUA), 4 M GUA and collagenase digestion. At one day following elastase injury, a 4.2 fold increase of 14C GlcN incorporation into HA released in 0.4 M GUA extract and a 2.6 fold increase into HS released in the collagenase digests were observed compared to control tissues; at 24 days, the increased 14C GlcN incorporation into HA and HS persist but to a lesser extent. Polyacrylamide gel electrophoresis and isoelectric focusing carried out on 4 M GUA extracts, demonstrated identical quantitative and qualitative distribution of 14C GlcN between the major SGP (140 and 110 K with pI 7.8 and 4.5 respectively) in the normal and the experimental groups. These results indicate that pulmonary SGP biosynthesis is not modified at one and 24 days after elastase injury, whereas HA and HS biosynthesis are consistently increased. These results suggest a specific role of these macromolecules in emphysematous injury of the lung.

Animals↗