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Biomedical subjects

A Knoblauch

Publications and source records attributed to A Knoblauch.

31 records · Page 2Linked to original sources
PubMed1990

[Home ventilatory support--retrospective view and perspectives].

Mechanical home ventilation is a child of this centuries polio epidemics. The tank respirator, or iron lung, signaled the beginning of the new era. Improved techniques like positive pressure ventilation via tracheostoma followed soon. Hypoventilation syndromes of various origin are more and more encountered thanks to better detection methods. They benefit from a new, efficient and noninvasive technique, the positive pressure ventilation via nasal mask.

History, 20th Century↗
PubMed1989

[Amborum Special F and ASFO--2 glucocorticoid-containing herbal remedies].

Amborum Special F and ASFO are two names of a herbal remedy which is adulterated with the glucocorticoid betamethasone. Patients with asthma, rheumatic and chronic diseases import the drug direct from Burbank, California, USA. Its impressive antiasthmatic effect is reported in two patients. While under therapy the first patient developed Cushing's syndrome and the second showed suppression of adrenal cortisol production. The manufacturer, who claims that the drug contains no "western medicine" and in particular no cortisone, is unscrupulous enough to recommend it for children under two years of age. We have observed that a marked glucocorticoid effect and marked glucocorticoid side effects are achieved with small doses of betamethasone. A review of the literature and the two cases reported here suggest that the equivalence doses given in textbooks and tables of glucocorticoid equipotency are incorrect for betamethasone. Betamethasone is a more potent glucocorticoid than hitherto reported.

Adult↗
PubMed1985

[Self-monitoring of airway obstruction using the peak flowmeter].

Daily peak flow measurements provide an accurate and objective assessment of airway obstruction. The peak flow profile offers a rational basis for antiobstructive treatment. Success and failure of treatment are visualized, as are the asymptomatic beginning of an asthmatic attack, an allergen exposure or an exercise-induced obstruction. Compliance improves, and self-monitoring seems to increase patient comfort. A considerable amount of knowledge about the dynamics of airway obstruction is conveyed to the physician, and this works very much to the benefit of his patient.

Adult↗
PubMed1984

[Oculopharyngeal muscular dystrophy].

A family from eastern Switzerland with oculopharyngeal muscle dystrophy is described. The history shows seven affected persons in three generations. The inheritance pattern is autosomal dominant with complete penetrance. Bilateral ptosis and dysphagia, the hallmarks of the disorder, appear in the fourth decade and progess slowly. The late stage is characterized by ptosis, causing reclination of the head and marked upright posture. Dysphagia may be disabling, causing starvation, or, as in the index case, death by aspiration pneumonia. Surgical procedures are available to correct the ptosis and alleviate dysphagia.

Aged↗
PubMed1983

Oxidant- and lipid-induced pulmonary vasoconstriction mediated by arachidonic acid metabolites.

In experiments using isolated rabbit lungs perfused with Krebs-Henseleit buffer in a nonrecirculating manner, we found that administration of an organic peroxide, tert-butyl hydroperoxide (t-bu-OOH), or Intralipid, an esterified mixture of unsaturated fatty acids, caused a marked vasopressor response which was associated with increased levels of thromboxane in the effluent perfusate. The vasopressor response to t-bu-OOH was greater in the lungs of vitamin E-deficient animals, and this could be correlated with an attenuated ability to increase prostacyclin production in these lungs. Conversely, administration of Intralipid to normal lungs caused marked increases in prostacyclin and a smaller pressor response. The magnitude of the pressor response was strongly correlated with the ratio of thromboxane B2 to the prostacyclin metabolite. No release of these mediators was associated with pulmonary vasoconstriction caused by administration of angiotensin II. The pressor response could be completely blocked by administration of indomethacin. We propose that this activation of the cyclooxygenase pathway of arachidonic acid metabolism may be important in the pathophysiology of oxidant lung damage.

6-Ketoprostaglandin F1 alpha↗
PubMed1981

Effect of hypoxia and CO on a cytochrome P-450-mediated reaction in rabbit lungs.

Evidence indicates that the diffusion of O2 and CO in tissue may be facilitated by a carrier molecule having a P50 that approximates tissue O2 partial pressure (PO2; 1-15 Torr) and a much higher affinity for CO than for O2. To determine whether cytochrome P-450 in lung satisfies these criteria, we measured the effect of hypoxia and of CO on the rate of metabolism of the cytochrome P-450 mediated O-demethylation of p-nitroanisole in isolated perfused rabbit lungs. Metabolism was inhibited by 50% of a control at an estimated tissue PO2 fo 4 Torr (5.5 microM). When inspired CO2 was kept at 200 Torr and inspired CO partial pressure (PCO) varied an estimated tissue PCO/PO2 ratio of 0.025 reduced the reaction rate by 50% of control, but some metabolism persisted at PCO/PO2 ratios larger than one. The relationship between reaction rate and PCO/PO2 ratio could not be fit by a single value for Haldane constant for M (CO affinity/O2 affinity) but could be described with a two-component model in which metabolism was equally divided between a high-affinity cytochrome (M = 200) and a low-affinity cytochrome (M = 2). These findings suggest that cytochrome P-450 could act as a carrier for O2 and CO in tissue with low PO2's.

Animals↗
PubMed1979

[Pathogenesis of bone marrow necrosis in a patient with cancer].

Bone marrow necrosis was observed in a 23-year-old pregnant woman with severe anemia and thrombocytopenia due to bilateral ovarian carcinoma. After removal of the primary tumors, the hematological findings returned to normal, but the progression of the metastasis lead to respiratory insufficiency and death. The possible mechanisms leading to bone marrow necrosis are discussed. In our case, it could be shown that emboli of tumor cells into the vessels of the bone marrow lead to the necrosis of the marrow. The embolization was temporarily stopped after removal of the ovaries.

Adult↗
PubMedDate not supplied

Pattern separation and synchronization in spiking associative memories and visual areas.

Scene analysis in the mammalian visual system, conceived as a distributed and parallel process, faces the so-called binding problem. As a possible solution, the temporal correlation hypothesis has been suggested and implemented in phase-coding models. We propose an alternative model that reproduces experimental findings of synchronized and desynchronized fast oscillations more closely. This model is based on technical considerations concerning improved pattern separation in associative memories on the one hand, and on known properties of the visual cortex on the other. It consists of two reciprocally connected areas, one corresponding to a peripheral visual area (P), the other a central association area (C). P implements the orientation-selective subsystem of the primary visual cortex, while C was modeled as an associative memory with connections formed by Hebbian learning of all assemblies corresponding to stimulus objects. Spiking neurons including habituation and correlated noise were incorporated as well as realistic synaptic delays. Three learned stimuli were presented simultaneously and correlation analysis was performed on spike recordings. Generally, we found two states of activity: (i) relatively slow and unordered oscillations at about 20-25 Hz, synchronized only within small regions; and (ii) faster and more precise oscillations around 50-60 Hz, synchronized over the whole simulated area. The neuron groups representing one stimulus tended to be simultaneously in either the slow or the fast state. At each particular time, only one assembly was found to be in the fast state. Activation of the three assemblies switched on a time scale of 100 ms. This can be interpreted as self-generated attention switching. On the time scale corresponding to gamma oscillations, cross correlations between local neuron groups were either modulated or flat. Modulated correlograms resulted if the groups coded features corresponding to a common object. Otherwise, the correlograms remained flat. This behavior is in agreement with experimental results, while phase-code models would generally predict modulated correlations also in the case of different objects. Furthermore, we derive a technical version from our biological associative memory model that accomplishes fast pattern separation parallel in O(log2 n) steps for n neurons and sparse coding.

Action Potentials↗
PubMedDate not supplied

Increased prevalence of perennial allergic rhinitis in patients with obstructive sleep apnea.

BACKGROUND: Impaired nasal breathing is a risk factor for obstructive sleep apnea syndrome (OSAS). OBJECTIVES: The aim of this study was to determine whether atopy to perennial allergens and existence of perennial allergic rhinitis was a risk factor for OSAS. METHODS: In a case-control study, we compared the proportions of OSAS patients with atopy to perennial allergens and perennial allergic rhinitis to the proportions in patients with chronic obstructive pulmonary disease (COPD). Seventy-two OSAS patients (mean age 60.7 years; 79.4% male) and 44 COPD patients (mean age 63.6 years; 88.6% male) were selected from a hospital outpatients' clinic in Switzerland. All patients completed a respiratory symptom questionnaire, performed spirometry and had a skin prick test for atopy. RESULTS: OSAS patients were significantly heavier than COPD patients (BMI 32.4 +/- (SD) 6.6 vs. 29.2 +/- 6.6 kg/m2, p = 0.04) and had a better lung function than COPD patients (FEV1% predicted 91.3 +/- 19.2 vs. 51.6 +/- 18.9%, p < 0.001). Patients with OSAS were more likely to be sensitized to perennial allergens such as house dust mite (23.6 vs. 4.5%, p = 0.009) and dog (18 vs. 4.5%, p = 0.04) than the COPD patients. Perennial allergic rhinitis (having nose problems [nasal obstruction and/or runny nose and/or sneezing] all year and being atopic to at least one perennial allergen) was reported in 11% of OSAS patients but in only 2.3% of COPD patients (p = 0.15). CONCLUSION: We conclude that subjects with OSAS may have an increased risk of being allergic to perennial allergens and suffer from perennial rhinitis. Awareness of this risk may have important consideration in the clinical situation.

Administration, Intranasal↗
PubMedDate not supplied

Major accidents related to manure: A case series from Switzerland.

Manure is an important element in the farm economy, but its storage and use are associated with risks. Major accidents related to manure exposure were analyzed using technical and demographic criteria. Of the 61 accidents, 44 were due to inhalation of manure gas, 11 involved falls into manure containers, and six were methane explosions. There were 49 fatalities, including 12 (24%) in which persons attempting to rescue primary victims died. 37 persons survived gas poisoning. Small children usually fell into the manure and drowned. There were 15 successful rescues and four cases in which primary victims saved themselves. The main danger is that of gradual or sudden manure gas intoxication, which is often fatal. However, almost a third of the accidents were due to falls into manure containers or manure gas explosions. Accidents in which victims of gas poisoning regained consciousness and saved themselves are also reported. Analysis of the accident circumstances confirms the importance of meticulous observation of existing safety guidelines with respect to both structural design and working practices. Specific measures at the scene can substantially increase the chances for survival of both primary victims and would-be rescuers.

Accidental Falls↗