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Biomedical subjects

G Hoffmann

Publications and source records attributed to G Hoffmann.

At least 199 records · Page 11Linked to original sources
PubMed1985

[Pest control in food establishments].

Pest control measures in rooms serving the production, treatment or marketing of foods have to be executed according to the principles laid down in the food hygiene regulations of the Länder of the Federal Republic of Germany. However, a proper pest control following these rules can only be realized if such control is performed by persons experienced and qualified in the field of hygiene. Corresponding knowledge includes diagnostic and accessory equipment, morphology, biology, sensitivity including resistance and vector function of the pest to be controlled, suitable pesticides, formulations according to the type of action, possible residual effect and indoor air exposure, the respective technique of application, decontamination procedures, structure and pH value of the materials used for the application, methods for the determination of the concentrations of the active substances and solvents in indoor air as well as of climatic factors in the resting and hatching area of pests, the shelf-life of foods, their protection against pesticides and their safe removal in the case of contamination.

Food Analysis↗
PubMed1984

Characterization of human spleen tumor glucocorticoid receptors using [3H]cortisol as ligand.

The present report describes an assay system allowing the quantification and characterization of [3H]cortisol binding to glucocorticoid receptors in bloodrich human tissue. The essence of this assay lies in the selective binding of 17 beta-carboxylic acids of natural corticoids to corticosteroid binding globulin (CBG). In the presence of 1240 nmol/l 11 beta-hydroxy-3-oxo-4-androstene-17 beta-carboxylic acid only glucocorticoid receptors were detectable with the expected properties: high affinity for synthetic and natural glucocorticoids, but failure to bind to the respective 17 beta-carboxylic acids, apparent Kd's at 0-4 degrees C for [3H]cortisol of approx 30 nmol/l, Nmax similar to those determined with [3H]dexamethasone and the typical sequence of relative binding affinities (dexamethasone greater than cortisol greater than progesterone greater than 17 beta-methyl-testosterone, estradiol).

Binding, Competitive↗
PubMed1984

Sleep and neuroendocrine disturbances in catatonia. A case report.

Sleep EEG investigations were performed in a 31-year-old catatonic male patient before and after electroconvulsive therapy and 3 months after recovery. The dexamethasone suppression test was also performed longitudinally together with measurements of CSF 5-HIAA, HVA and 24-h urinary MHPG. A normal male control aged 32 was also investigated. Sleep analysis showed reduced REM latency and increased REM activity and density during the catatonic phase before treatment when compared to the age-matched control. REM latency remained shortened after recovery following ECT treatment and 3 months after recovery. Dexamethasone suppression test, abnormal before treatment normalized with clinical improvement during ECT. Urinary MHPG values were low in the catatonic state and did not change after ECT treatment. CSF HVA and 5-HIAA were also low in the pretreatment period and increased during the 3 months follow-up period. There results indicate that some cases of catatonic behavior may be linked to affective disorders.

Adult↗
PubMed1984

Electroencephalogram and neuroendocrine parameters in pubertal and adolescent depressed children. A case report study.

EEG sleep recordings and two provocative neuroendocrinological tests (the DST and the GH stimulation test after desipramine) were investigated in two depressed pubertal monozygotic twin boys with Major Depressive Disorder and compared with results from one normal pubertal control boy and an adolescent girl suffering from major depression. REM latency was reduced in the adolescent depressed girl but not in the pubertal depressed twin children when compared to the normal control. Sleep continuity and sleep architecture were, however, disturbed in pubertal and adolescent depression as a function of severity of the depressive state. The results of the DST showed abnormal cortisol values in the most severely depressed twin and in the depressed adolescent. GH secretion after DMI showed a clear GH response in the less depressed twin and in the normal subject while in the depressed adolescent, the GH response was blunted. The findings suggest that REM latency disturbances in our depressed patients do not appear before adolescence, while neuroendocrine dysfunction can already be present in pubertal depression.

Adolescent↗
PubMed1984

[Biometry of the large bones of fetal extremities in the 3d trimester].

Ultrasound measurement of head, thorax and the limb bones femur, tibia, humerus and radius was made of 285 fetuses with known gestational age. In addition measurements of the fibula were obtained in 120 fetuses and of the ulna in 125 fetuses. With the use of these data a normal growth curve for each limb bone was established, which can be helpful in detecting late fetal limb malformations as heterozygous achondroplasia. All limb bones show a nearly linear growth rate so that the length of the bones can alternatively be used to determine gestational age. The linear relationship between growth of the limb bones and the fetal head can be used to diagnose fetal head malformations as microcephaly.

Arm↗
PubMed1984

[Amniotic band syndrome in ultrasound].

Ultrasonographic examination during pregnancy is of great value in detecting changes in the amniotic fluid such as oligohydramnios, and severe fetal malformations, before the 24th week of pregnancy. A case of ADAM syndrome in the 22nd week of pregnancy is reported. In this case, the sonographic findings were very marked. The pathogenesis of the malformation is discussed.

Amniotic Band Syndrome↗
PubMed1984

[A new LH-RIA rapid test for determining peak levels of serum LH--a methodological contribution to in-vitro fertilization].

A highly sensitive, easy to operate LH-RIA rapid test was developed by changing the incubation period and temperature and by reducing the standard curve to three measurement data, using commercially available reagents. The results obtained by means of the LH-RIA rapid test correlate most loosely with those of a conventional 5-hour LH-RIA. The new LH-RIA rapid test is ideally suited for LH peak search at short intervals for exact determination of the time of ovulation as part of in-vitro fertilisation or insemination.

Adult↗
PubMed1984

Dexamethasone suppression test and REM sleep in patients with major depressive disorder.

Dexamethasone suppression Test (DST) and sleep electroencephalogram (EEG) recordings were carried out during three consecutive nights in 39 depressed patients who met Research Diagnostic Criteria (RDC) for major depressive disorder and in nine normal controls. Cortisol response to DST was abnormal in 26 patients and normal in all controls. REM latency and REM density were compared in patients with abnormal DST (n = 26) to values obtained in patients with normal DST (n = 13) and in normal controls (n = 9). Rapid Eye Movement (REM) latencies were significantly lower in depressed patients showing cortisol non-suppression after dexamethasone than in patients with a normal DST or in controls. REM densities were significantly higher in depressed patients than in normal controls (P less than 0.025), but there was no significant difference between DST suppressors and non-suppressors. The DST provided high specificity (100%) and a sensitivity of 67%, while REM latency showed a lower specificity (78%), but a higher sensitivity (85%).

Adolescent↗
PubMed1983

3H-estradiol and 3H-R5020 binding in cytosols of normal and neoplastic human ovarian tissue.

High-affinity cytoplasmic estrogen and progesterone receptors in normal and abnormal ovarian tissues were studied. Estradiol receptor was detectable in 65% and progesterone receptor in 36% of the malignant tumors; 39% of all malignant ovarian tissues were estradiol- as well as progesterone-receptor-positive. Tumors were said to be receptor-positive when the receptors bound greater than 5 fM steroid/mg cytosol protein. No correlations were found between receptor status and histopathological diagnosis. In normal ovarian tissues collected at various phases of the menstrual cycle no changes in [3H]-estradiol and [3H]-R5020 binding could be detected. Analysis of the receptor concentration for both steroid hormones with regard to the menopausal status demonstrated highest levels in postmenopausal women. No significant difference could be found when two groups of patients with advanced ovarian carcinoma associated with the cytosol estrogen receptor status were compared in terms of two different therapeutic schemes (cytosolic chemotherapy with and without tamoxifen).

Cytosol↗
PubMed1983

Optimization of Brownian search strategies.

What are the simplest search strategies that lead an animal to a particular target, what are their limitations, and what changes can be made to develop more effective strategies? To answer these questions a class of search strategies was examined that require an animal to have only a minimal capacity for spatial orientation; the effectiveness of such strategies in solving the following basic search problem was determined. The animal begins its search at a distance r0 (starting distance) from a spatially fixed target. It detects the target when it has approached it to within a certain distance a (the detection radius). The analysed class of search strategies has the following characteristics: C1. The animal uses the same search strategy in all regions it enters. Therefore it needs no information as to the actual location of the target. C2. Its search strategy is constant in time. The animal has only to detect whether it has reached the target or not. C3. Once the animal has chosen a direction, it continues in that direction for a certain distance. This is the only way in which the preceding parts of the search affect the animal's decision as to the direction in which it will search next. In the long term the animal's movement directions are independent, with no preference for any particular direction. Despite their extreme simplicity in application these "Brownian" search strategies are remarkably successful (Fig. 1). Indeed, if the search is continued long enough the target is certain to be found. The success of the search depends in part on the search duration (Fig. 2) or the search-path length S, the starting distance and the detection radius. On the other hand, an animal can have a decisive influence on its degree of success simply by adjusting the frequency with which it changes its walking direction to match its sensory abilities. That is, a not-too-short Brownian search (S much greater than r0) is most successful when the searching animal, between the points at which it changes direction, walks approximately straight for a distance equal to the detection radius (Figs, 3 and 4). A further increase in search effectiveness is possible only by turning to another class of search strategies. These, however, demand that the animal either have more information about the position of its target at the beginning of the search or be able to organize its search behavior even over fairly long periods of time.

Animals↗
PubMed1983

[Pregnancy and hyperprolactinemia].

After endocrinological and radiological evaluation of a hyperprolactinemia 13 patients became pregnant under bromocriptine therapy. In two of these patients a selective adenomectomy was performed by the transphenoidal route because of a prolactin (PRL) secreting adenoma. In 12 patients the pregnancy was not complicated. The serum PRL levels were different but mostly in a normal range. The control of x-ray and visual field in patients with a rapid increase of the PRL levels did not result in a tumor recurrence. After a normal course of the serum PRL concentrations one patient with a microadenoma developed suddenly a chiasma syndrome in the 31th week of gestation. The further evaluation resulted in a pituitary tumor with suprasellar extension. The discrepancy between the radiological result and the normal serum PRL levels was explained by a hemorrhage into the adenoma. After the operation the chiasma syndrome was reversible within a short period. Altogether, the course of the pregnancies was not complicated. We did not see fetal malformations. Post partum the sella x-ray of all patients did not reveal any significant changes so far.

Adenoma↗
PubMed1982

A familial progressive neurodegenerative disease with 2-oxoglutaric aciduria.

A boy and a girl born to a consanguineous Tunisian couple are suffering from a slowly progressive nervous disorder. Initially they both had normal psychomotor development with acquisition of gait and speech. First symptoms in the boy were athetoid movements during the second year of life. He later lost all motor and language skills and developed muscular rigidity and intention tremor. At the age of five years, he was completely bedridden while he appeared mentally much less affected. His younger sister followed a similar course. The major specific abnormality detected was a strikingly elevated excretion of 2-oxoglutaric acid, which was identified by gas liquid chromatography, mass spectrometry, and enzymatic analysis. 2-oxoglutarate dehydrogenase activity in homogenates of cultured skin fibroblasts was reduced to about 25% of control values in both children. Although the pathogenetic mechanisms leading to brain damage remain obscure, the finding strongly suggest an autosomal recessive neurometabolic disease with predominant involvement of the extrapyramidal system.

Basal Ganglia Diseases↗
PubMed1982

[Studies of monocytopoiesis in patients with malignant disease and after immunostimulation with BCG, using 3H-thymidine as a DNA-label (author's transl)].

Monocytopoiesis and blood monocytes were investigated in patients with Hodgkin's disease, non-Hodgkin lymphomas, mycosis fungoides, breast cancer or melanoma. The investigation was carried out before surgery and just before each application of BCG. Monocyte production was increased in untreated patients. Postoperative prophylactic BCG-vaccination gave rise to increased proliferation activity. However monocyte production returned to normal between the 4th and 6th month of BCG immunotherapy. These results indicate that monocytopoiesis is stimulated by human tumors. BCG immunostimulation is able to increase proliferation activity during the first month of treatment only.

BCG Vaccine↗