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Biomedical subjects

G Hoffmann

Publications and source records attributed to G Hoffmann.

At least 235 records · Page 13Linked to original sources
PubMed1979

Meniere's disease: a neuropsychological study II.

23 Meniere patients were examined with an extensive battery of neuropsychological tests. In a previous investigation the authors had demonstrated that patients with a long duration of Meniere's disease had psychological disturbances, presumably localized in the nondominant hemisphere. In the present investigation the patients had a short duration of the disease, and we were unable to reproduce the psychological disturbances. It is concluded that the central changes in the nondominant hemisphere function develop over a long period of time. It is hoped for that further neuropsychological investigations of Meniere patients can give more information of what is primary in Meniere's disease: peripheral sensory or central neurological changes.

Adult↗
PubMed1979

[Dose distribution of bone-seeking radiopharmaceuticals in the rat (author's transl)].

The biokinetics of 32P-P, 32P-PPi, 85Sr, 99mTc- and 113Sn-EHDP were evaluated in the young rat. The dose distribution of the beta-emitters 32P, 89Sr, 121Sn and 188Re was calculated from the measured biological half-lifes. The highest dose to soft tissues and therefore also to bone-marrow in relation to the bone dosis was found for 32P-P. The lowest dose was found for 89Sr. Favourable results were obtained in the diphosphonate compounds. The use of 32P-PPi instead of 32P-P appears to be advantageous, too. The dose relation between normal bone and the growth plate of the femur was significantly lower for 89Sr than for the other radiopharmaceuticals.

Animals↗
PubMed1979

Maturation of REM-patterns from childhood to maturity.

The operational value of measuring paradoxical sleep (PS) as a percentage of total sleeping time has been questioned. The purpose of this study was to determine the interactions between the variations in hormonal secretions and paradoxical sleep in women of different age-groups. Three parameters were utilized: REM-percent, REM-density and the eye movement frequencies. The distribution of the time-intervals between the oculomotor signals as indicated by the ratio of the higher to the lower eye movement frequencies gives a clue as to the significance of the spatio-temporal organization of the brain-signals during paradoxical sleep. This notion introduces an internal temporal and dynamic dimension in the concept of REM or Paradoxical Sleep. From our results it appears that the changes in the ratio between the different types of oculomotor discharges are a function not only of hormonal fluctuations but also of age. This point of view opens a new possibility of interpreting the results.

Adolescent↗
PubMed1979

Complexing of reduced technetium and tin(II) by chelating phosphate compounds. II. In vitro stability of pyrophosphate and ethane-1, hydroxy-1, diphosphonate (EHDP) complexes.

The in vitro stability of 99mTc- and 113Sn-pyrophosphate and ethane-1, hydroxy-1, diphosphonate (EHDP) complexes was studied by varying the mode of preparation. The 1-hr distribution in the rat was used as an indicator for complex formation or destruction. A maximum of bone uptake and urinary excretion and a minimum of soft tissue concentration was obtained if there was an excess of phosphate in relation to tin(II) in the equilibrium. Formation of tin(II) colloid was favoured in the presence of an excess of tin(II) in the equilibrium, 99mTc colloid occurred with some delay. After dilution in neutral normal saline the chelates were more or less destroyed, as shown by a 113Sn(II) colloid formation whereas the 99mTc-phosphate complexes were transformed into a 99mTc kidney agent. At pH 11 the 113Sn(II)-phosphate complexes proved to be stable, the 99mTc-phosphate complexes were also transformed into the 99mTc kidney agent. Oxidation of all tin(II) in the equilibrium by hydrogen peroxide did not change the distribution patterns of 113Sn, 99mTc was oxidized to pertechnetate. In general complexes between tin(II) and chelating phosphate compounds proved to be more stable than those with reduced technetium. EHDP was found to form stronger complexes with tin(II) and reduced technetium than pyrophosphate.

Animals↗
PubMed1979

Complexing of reduced technetium and tin (II) by chelating phosphate compounds. I. Chemical state of technetium.

Complexing of reduced 99mTc, 99Tc and of 113Sn(II) by pyrophosphate was studied, using the in vivo distribution in the rat as an indicator for complex formation. 99mTc-pyrophosphate was only formed at very low technetium concentrations, otherwise colloid formation occurred. Reduced 99mTc in trace amounts and 113Sn(II) complexed equimolarly with pyrophosphate were concentrated in bone and excreted in urine in comparable amounts. The in vivo distribution of 32P-orthophosphate and -pyrophosphate was characterized by a considerable uptake in the liver and a poor urinary excretion. The distribution patterns of 32P-pyrophosphate, complexed equimolarly with tin(II), remained unchanged. Despite these findings it is concluded that real chelates are formed, since non-complexed reduced 99mTc was not concentrated in bone. Two variants of reduced technetium could be discerned: a 99mTc-kidney agent and a 99mTc protein-bound agent. Some evidence was found that reduced technetium may change its oxidation state, but it seems much more likely that both agents are technetium(IV) compounds. It is suggested that the kidney agent is hydrated technetium dioxide whereas the protein-bound agent is a charged technetium(IV) compound. Only hydrated technetium dioxide is obviously complexed by chelating phosphate compounds.

Animals↗
PubMed1978

Menière's disease. II. A neuropsychological study.

23 Menière patients were examined with a extensive battery of neuro-psychological tests. In a previous investigation, the authors had demonstrated that patients with long-duration Menière's disease had psychological disturbances, presumably localized in the nondominant hemisphere. In the present investigation, the patients had short-duration Menière's disease, and we were unable to replicate the results of the former investigation. It is concluded that the central changes in nondominant hemisphere function develop over a long period of time. It is hoped for that further neuropsychological investigations of Menière patients will give more information on what is primary in Menière's disease: peripheral, sensory or central neurological changes.

Adult↗
PubMed1978

Estimation of cardiac function by means of radiocardiographic function analysis.

The radiocardiographic function analysis represents a relatively simple procedure for the clinician to collect information concerning the changes of cardiac dynamics. The advantage of this method is to register non-invasively changes in cardiac dynamics at rest and during exercise such as those of enddiastolic volume, stroke volume, endsystolic volume, ejection time and filling time, and to permit the calculation of mean ejection velocity, etc. After insertion of a cardiac catheter, it is possible to record the corresponding pressure pulse in the right ventricle or in the pulmonary vessels simultaneously.

Cardiac Catheterization↗
PubMed1977

[Possibilities and limitations of hysteroscopy in the diagnosis of uterine neoplasms].

The use of hysteroscopy for the diagnosis of corpus neoplasma has its limitations. In 180 cases with suspected neoplasma or with an unknown localisation of a corpus neoplasma, identification by histology and hysteroscopy was performed. The results lead to the conclusion that the CO2-hysteroscopy is a valuable additional method in single cases. As an endoscopic method however, it cannot replace the sample of cell material and histologic preparation. Hysteroscopy might be of clinical value not only for the localization of a tumor with reoccurring bleeding after a negative curettage, but also to evaluate the extent of a malignant tumor. However, this method takes too much time for it to be recommended as a screening method.

Adenocarcinoma↗
PubMed1977

[The "stimulatory proteodyschylia" in the amitriptylin (Laroxyl) treated rat parotid gland. Experiments on the effect of antidepressive pharmacotherapy on the parotid glands of the rat (author's transl)].

The activity of total amylase and isoamylases in the rat parotid gland is reduced by treatment with Amitriptylin (Laroxyl) for 3 and 7 days while the protein content of the glands remains constant. These changes are no longer visible after treatment for 21 days and following a period without drug application. To differentiate the disturbances of protein secretion (proteodyschylia) prominent in the clinical picture of sialadenosis, the following classification is proposed. We suggest the term "stimulatory proteodyschylia" for a decrease of acinar amylolytic activity, here caused by Amitriptylin application, as opposed to the "inhibitory proteodyschylia" characterized by an acinar amylase congestion.

Amitriptyline↗
PubMed1977

Kinetics of various 99mTc-Sn-pyrophosphate compounds in the rat. I. In vivo studies.

The kinetic data of two different 99mTc-Sn-pyrophosphate compounds (compound A and B) were evaluated in non-adult rats. Only compound A concentrated in bone. Both compounds dispersed rapidly in the intravascular as well as the extravascular space. The plasma protein bond of both compounds increased with time after injection and impaired both the renal clearance of both compounds and the bone clearance of compound A. The renal clearance of both compounds was somewhat above that of 51Cr-EDTA. It is concluded that compound A and B is mainly excreted by glomerular filtration. About one fourth of the glomerular filtrate of compound B is reabsorbed and accumulated by the tubular cells.

Animals↗
PubMed1976

[A new immunochemical tube test for pregnancy using the latex-agglutination inhibition reaction. II. Clinical results (author's transl)].

In a multi-centre study 1117 morning urine samples were tested using the new immunochemical pregnancy tube test (Roche), based on the principle of indirect latex-agglutination inhibition. The test proved to be both qualitatively and semi-guantitatively suitable for demonstration of HCG in urine. There was only one false-negative result among 320 pregnancy tests (after 50th postmenstrual day). In 94 early pregnancies (test done before the 50th day) there were only two false-negative results. No false-positive result were seen. In the prognosis of threatened abortion, diagnosis of incomplete abortion, hydatid cyst, or chorionepithelioma the semiquantitative performance of the test was clinically useful and especially suitable because the result of the agglutination-inhibition reaction is unequivocal.

Abortion, Incomplete↗
PubMed1976

[A new immunochemical tube test for pregnancy, using the principle of the latex-agglutination inhibition reaction. I. Basic studies (author's transl)].

In a joint study of five laboratories the immunochemical tube test for pregnancy 'Roche', which uses the principle of the latex-agglutination inhibition test, was examined. A total of 1117 samples, complemented by a number of laboratory studies, proved that the test is specific, reproducible and low in interference with a sensitivity of 900-1000 U/l HCG. It is a simple test, the results can be easily read after 90 minutes. pH of the urine sample, protein, urea or calcium content, presence of oral contraceptives, detergents, disinfectants or organic solvents cause no or very little interference.

Calcium↗