Search PubMed⌕ Search

Biomedical subjects

G Hoffmann

Publications and source records attributed to G Hoffmann.

At least 217 records · Page 12Linked to original sources
PubMed1982

[Testing pest control products for use under the Federal Communicable Disease Act].

The examination of pest control products and procedures under section 10 of the Federal Communicable Diseases Act is restricted to such products and procedures which are useful for the official control of arthropods as vectors of communicable diseases, i.e. which are effective and safe from the toxicological point of view if properly used. Insecticides and acaricides which are mainly intended for application in the household by laymen such as pressurized aerosol and strip formulations as well as products against nuisances such as silverfishes, dust mites or wasps are thus not accepted for examination, apart from a few exceptional cases where examination is still required. The examination of the products and procedures is first performed in the laboratory and then in the field if laboratory tests have revealed their effectiveness. Products and procedures are tested for their effectiveness, i.e. their knock-down, repellent, flashing, immediate and/or long-term effects. This is done on substrates of varying sorption capacities and with different pH values against all stages of development and nutrition in the indicated fields of application and, as far as necessary, also against strains of varying sensitivity of the species to be controlled.

Communicable Disease Control↗
PubMed1982

[House-dust mites as vectors of human diseases].

The genuine European house-dust mite, Dermatophagoides pteronyssinus, is the producer of the most common and most potent allergen in the house-dust in Central Europe. Such allergens causing asthma, rhinitis, tracheitis, bronchitis and/or conjunctivitis in man may also be produced by the other species of house-dust mites such as D. farinae and Euroglyphus maynei. House mites and mites of stored products rarely account for such diseases but more frequently for acarodermatitis--especially on farms. Allergies due to house-dust mites mainly occur in midsummer and in early autumn. Particularly children under 10 years of age are effected by these allergies. Textile articles such as mattresses, upholstered furniture and carpets are breeding places of the genuine house-dust mites. Skin scales of humans, mammals and birds affected by mould provide the nutritional substrate of the mites.

Arthropod Vectors↗
PubMed1981

[Scintigraphic diagnosis of sport injuries: multiple fractures of ribs by golf-players (author's transl)].

Three untrained golf-players suffered from pain in the dorsal region of the left thorax after some training hours. Three to four weeks after the pains had begun serial fractures of ribs were diagnosed by 99mTc-MDP bone-scan-examinations. All fractures were localized near the costal angulus (paravertebral) of these ribs. The fractures are causal by manual tensions. The difficulties in timing the bone-scan and in identifying the morphologic substrate are demonstrated. It is recommended, that golf-players suffering from thoracic pain ought to be examined by bone scan.

Adult↗
PubMed1981

About the possibilities of registration of drug influence by means of radiocardiographic function analysis.

Changes in cardiac dynamics were analyzed by means of radiocardiographic function analysis under an infusion of epinephrine using the method of RAB. Typical changes in heart rate, stroke volume and blood pressure were observed after the application of epinephrine. Compared to examinations under physical exercise in case of healthy control subjects there was no typical decrease of enddiastolic volume dependent on the heart rate. Ejection time and ejection velocity was placed within the variation compared to values of a control group under physical exercise but there was a steeper increase of the curve under the effect of epinephrine. Under the influence of Solcoseryl no significant change could be observed in this series of tests compared to the basic values. The effect of epinephrine was changed by Solcoseryl in the way of an essentially smaller rise in heart rate and of a definite prolongation in diastolic time. A change in ejection time under the influence of epinephrine after the application of Solcoseryl could not be found. This allows the conclusion, that under the influence of Solcoseryl and after the administration of epinephrine better conditions for the metabolic restitution of heart muscle are given and consequently a direct effect of Solcoseryl on the heart muscle can be assumed.

Actihaemyl↗
PubMed1981

[Gated blood pool studies with a single probe--clinical validity (author's transl)].

The global volume alterations of the heart can be estimated non-invasively by means of the "radiocardiographic function analysis" developed by Hoffmann and Kleine. Since the failing heart with its functional disturbances demonstrates a pathological volume behavior under physical exercise, it is possible to use these characteristic to differentiate between the intact heart and the failing heart by registration of the global volume alterations. The "gated blood pool technique" combined with the registration of the intraventricular pressure pulse by means of a Swan-Ganz flow-directed catheter enables demonstration of ventricular stroke work as a pressure-volume loop (work diagram). Its shape indicates whether the ventricle has to perform mainly pressure work or volume work. Myocardial failure is altering the basic conditions of the heart. The work diagram of the failing heart is significantly different from that of the intact human heart. It is shifted in its pressure-volume coordinates according to an increase of EDV and ESV and the rise of the filling pressure. Case demonstrations reveal the global volume behaviour of the heart under varying conditions: resting and physical exercise, drug influence on the intact and failing heart.

Cardiac Pacing, Artificial↗
PubMed1980

[Steps in the synthesis of prostaglandins in the serum during and following delivery (author's transl)].

The levels during and following delivery are investigated of the unesterified fatty acids (UFS), of the prostaglandin precursors arachidonic and Dihomo-gammalinolenic acids and of their possible essential precursor oleic acid. The summation curve of the total fraction of the unesterified fatty acids contains different patterns of different fatty acids. 24 hours after delivery only oleic acid and arachidonic acid are significantly increased. The patterns of glycerine, the triglycerides and the ketone bodies, the acetate and the beta-hydroxy butyrate show the different changes of the fatty acids in correlation to lipolysis, to beta-oxidation rate of fatty acids, to lipogenesis and to an increased turn over of prostaglandins.

Arachidonic Acids↗
PubMed1980

[A new method of combined inhalation and perfusion scintigraphy for the diagnosis of pulmonary embolism (author's transl)].

The combined inhalation and perfusion scintigraphy as a specific identification method of thromboembolism of the lung was tried out in 132 patients. A fine aerosol with selected droplet size was produced in a newly developed atomiser device and inhaled by taking a few deep breaths. Perfusion scintigraphy, which was performed immediately after inhalation scintigraphy, was effected with the same radioisotope, 99mTechnetiun. The disadvantages of inhalation scintigraphy, which are inherent in the method itself, were reduced to such an extent that it was possible to distinguish clearly between primary and secondary disturbances of pulmonary perfusion even in obstructive diseases of the respiratory tract, provided perfusion was disturbed in sufficiently large areas, i.e. of segment or lobe size.

Aerosols↗
PubMed1980

Bone uptake of 99mTc-phosphate via labeled plasma protein.

The transfer of albumin into the extravascular space of bone and other tissues was evaluated in the non-adult rat and was found to be less rapid in bone than in the liver and kidneys but more rapid than in muscle. Protein binding of 99mTc increased continuously with time after injection of 99mTc-EHDP and -PPi. One hour after administration, about 20% of the plasma activity of 99mTc-EHDP and 90% of 99mTc-PPi was bound to proteins. Thus the possibility exists that the fixation of 99mTc through protein binding in the extravascular space of bone contributes significantly to the regular bone uptake of 99mTc-phosphates, in the event that relatively unstable compounds such as 99mTc-PPi are used.

Animals↗
PubMed1980

Relationship between complex stability and biokinetics of 99mTc-phosphate compounds.

The complex inertness of 99mTc-EHDP, -MDP, -PPi and -TriP was determined in vitro by means of protein binding of 99mTc after dilution in a phosphate-buffered albumin solution. Commercially available kits were used. In vitro, 99mTc-EHDP was found to be the most stable complex. The biodistribution of these agents was evaluated in the adult rat; here the less stable 99mTc-MDP proved to be the superior bone imaging agent. It is suggested that the complex inertness and the bone affinity are opposing properties of the 99mTc-phosphate compounds, because the complex must hydrolyse before the phosphate compound and technetium (IV) are deposited separately in bone. Hence, bone imaging with 99mTc-phosphate compounds demands a compromise concerning the stability of these complexes at low ligand concentrations, which among the investigated agents is best accomplished by 99mTc-MDP.

Animals↗
PubMed1979

Relationship between blood flow and radiostrontium uptake in the healing bone fracture.

The healing of a diaphyseal tibia fracture was followed in the rat. Callus formation, blood flow and Sr-85 uptake were assessed by a ratio comparison of the fractured to the contralateral side. No correlation was found between blood flow and Sr-85 deposition in the callus and the adjacent bone of the same extremity. It is concluded that the deposition of a radiopharmaceutical in bone is primarily related to the presence of calcifiable organic bone matrix and only secondarily to the bone formation rate and to variations in the local blood flow.

Animals↗
PubMed1979

The short-term fixation of radiopharmaceuticals in bone.

The relationship between local blood flow and bone clearance of 18 F, 32 P-P (orthophosphate), 32 P-PPi (pyrophosphate), 45 Ca, 85 Sr, 99mTc- and 113 Sn-EHDP was evaluated in the non-adult rat. During one single blood passage nearly 100% of 18 F was extracted in the femoral diaphysis, the extraction efficiency for the other radiopharmaceuticals was about 40%. Blood flow and bone clearance was higher and the extraction efficiency lower in the distal femoral epiphysis including the growth plate. The short-term bone uptake of 32 P-P was lowered considerably by the simultaneous application of inactive orthophosphate, whereas the bone uptake of 32 P-PPi was not suppressed. It is suggested that the rapid deposition of radiopharmaceuticals in bone is not caused by an ionic exchange process on crystal surfaces of already existing mineral but is due to an ionic exchange during the precipitation of calcium phosphate in the calcifying bone matrix. Only 18 F is exchanged with hydroxyl groups of already precipitated hydroxyapatite, whereas the calcium and phosphate ions in the precipitated hydroxyapatite are not further accessible to an exchange process.

Animals↗