Search PubMed⌕ Search

Biomedical subjects

K Herrmann

Publications and source records attributed to K Herrmann.

At least 91 records · Page 5Linked to original sources
PubMed1986

Monocular deprivation affects neuron size in the ectostriatum of the zebra finch brain.

The effects of different periods of monocular deprivation on cell sizes in the ectostriatum, the telencephalic relay of the tectofugal pathway in zebra finches, were evaluated. Following 20 days of monocular closure, neurons in the deprived and undeprived hemisphere show an unselective hypertrophy of 10%. Extending the deprivation period results in a shrinkage of neurons of the deprived side to values of adult normally reared birds, whereas the non-deprived neurons maintain their hypertrophied size.

Animals↗
PubMed1986

Delayed development of song control nuclei in the zebra finch is related to behavioral development.

The postnatal development of two visual areas (nucleus rotundus and ectostriatum) and two song control areas (hyperstriatum ventrale pars caudale, HVc, and nucleus robustus archistriatalis, RA) of the zebra finch brain was followed from birth to adulthood. The following parameters were investigated: (1) neuron size, (2) volume of the brain nuclei, and (3) myelination of axons. The nucleus rotundus, the diencephalic station of the tectofugal pathway, exhibits the fastest development: rotundal neurons reach their maximum size at 20 days of age; the volume of this structure reaches adult size at the same time. The process of myelination begins between day 5 and day 10 and is completed at 40 days of age. A similar temporal sequence of development is seen in the ectostriatum, except myelination starts some days later. Thus the development of these visual areas is completed at 40 days. In contrast, the development of the song control nuclei is delayed. Neurons in RA and HVc grow steadily up to 40 days of age, attaining a size larger than that observed in adults. Whereas the volume of HVc increases until day 40 and remains stable thereafter, RA volume increases until day 70 and evidences a decrease thereafter. It is not until postnatal day 20 (RA) and day 40 (HVc) that the myelination process starts in the song control areas. Adult myelin density is achieved by 70 days in RA and by 100 days in HVc. It can be demonstrated that the development of the visual system parallels the development of visual performance of the birds. Delayed growth of song control nuclei coincides with development of song.

Aging↗
PubMed1986

Effects of monocular deprivation in the nucleus rotundus of zebra finches: a Nissl and deoxyglucose study.

We evaluated in zebra finches the effects of monocular deprivation on morphological and physiological features of the nucleus rotundus, the thalamic relay station of the tectofugal pathway. In a first series of experiments neuron size and total volume were estimated in animals deprived for 20, 40 and at least 100 days and compared to values obtained from normally reared birds. Monocular closure for more than 40 days causes a marked hypertrophy in cells receiving their main input from the open eye, whereas the deprived cells are normal in size. However, with only 20 days of monocular deprivation both deprived and non-deprived rotundal neurons are larger than normal. This indicates that monocular closure has a biphasic effect: firstly, an unselective hypertrophy of deprived and non-deprived neurons, and secondly, a subsequent period of shrinkage of the deprived cells to normal values, while cells driven by the open eye remain hypertrophied. The total volume of the deprived n. rotundus turns out to be smaller in all age groups. In a second series of experiments the activity of the n. rotundus of animals monocularly deprived from birth for 100 days was investigated with the 2-deoxyglucose-method (Sokoloff et al. 1977). With binocular stimulation the activity of the deprived n. rotundus was reduced by about 40%. Depriving adult animals for 100 days does not result in asymmetric labeling of the n. rotundus. We interpretate the 2-DG data as evidence for the existence of a sensitive period for the effects of monocular deprivation. The anatomical data suggest, however, that the effects of monocular deprivation in birds are different from those observed in mammals.

Animals↗
PubMed1986

[Organic acids of various kinds of vegetables. IV. Changes in the acids and sugar in tomatoes, sweet peppers and cucumbers during development and ripening].

Concentrations of organic acids and sugars in tomatoes and sweet peppers change notably during ripening. The concentration of malic acid decreases while that of citric acid increases considerably and in redripe fruits clearly exceeds the content of malic acid. Several maxima and minima in acid concentrations occur during development. Both species show constant proportions of citric and isocitric acid (200:1 and 30:1 respectively). In sweet pepper, quinic and ascorbic acid can be found in noticeably higher amounts than in tomatoes. Additionally, succinic acid was detected in tomatoes and fumaric and shikimic acid in sweet pepper. Glucose and fructose, in approximately equal amounts, are the main sugar components; their concentrations are increased during ripening, especially in sweet peppers. The leaves of tomatoes and sweet pepper contain more malic acid and less citric acid than redripe fruits, though here as well citric acid predominates. There is considerably less glucose and fructose present in the leaves of sweet pepper than in the fruits while sucrose is increased. Sucrose is the main sugar component in the leaves. Compared to tomatoes and sweet peppers, egg-plants contain more amounts. - Potatoes contain citric, malic, quinic, succinic, fumaric, and soluble oxalic acid (in order of decreasing amounts). - In cucumbers malic acid notably exceeds citric acid. Both acids hardly change in concentration during ripening. Sugar content decreases during ripening.

Acids↗
PubMed1986

Arousal enhances [14C]2-deoxyglucose uptake in four forebrain areas of the zebra finch.

The activity pattern of the forebrain of male zebra finches was investigated by the [14C]2-deoxyglucose (2-DG) method in 4 different behavioral situations. Sitting alone in the cage (control); courtship by experienced birds; first courtship of inexperienced birds (100 days of age), and chasing the birds around the cage. The primary sensory areas (ectostriatum, field L) were active above background in each experiment. Vocal-motor control areas were at background activity (RA, HVc, MAN), or below background (area X), all unaffected by the type of experiment. In contrast, 4 different areas were active in Expts. 3 and 4, but not in 1 and 2: part of the neostriatum intermedium; part of the lateral neostriatum, both with adjacent parts of the hyperstriatum ventrale, hyperstriatum accessorium and hyperstriatum dorsale, a portion of the caudal neo/archistriatum. It is concluded that the enhanced activity of these areas is not due to distinct external stimulation or enhanced motor activity, but correlates with high arousal levels of the animals.

Animals↗
PubMed1986

Immunity against measles and rubella in Massachusetts schoolchildren.

A statewide serosurvey was conducted among 6th, 10th and 12th grade Massachusetts schoolchildren in 1982. Sera were screened using a standard measles hemagglutination inhibition (HI) assay, a sensitive measles plaque neutralization assay, and four rubella assays with corresponding sensitivity limits of approximately 15, 10, 7.5, and 5 international units (IU) of rubella antibody/ml respectively. Using the most sensitive assays, seroprevalence was 98.6% for measles antibodies and 93.1% for any rubella antibodies. For persons who received single doses of either combined measles and rubella vaccines or separate single vaccinations at different times, there were no significant differences in seroprevalence using sensitive assays. Of persons who received combined vaccines, 99.3% had antibody against measles compared to 98.4% of single antigen recipients. For rubella, 98.6% of combined vaccine recipients had antibody compared to 95.7% of single antigen recipients. These seroprevalence data indicate the effectiveness of a combined vaccination program and support epidemiologic data indicating virtual elimination of these diseases in Massachusetts schoolchildren.

Adolescent↗
PubMed1985

[Organic acids in vegetables. I. Brassica, leaf and bulb vegetables as well as carrots and celery].

18 German vegetable species were analyzed for their organic acid content. Organic acids were isolated by methanol extraction followed by ion exchange. After derivatisation with BSA the trimethylsilyl derivatives were analyzed by gas chromatography using SE-52 and OV-1701 glass capillaries. The predominate acids are malic and citric acid, and in most cases malic acid was the most abundant. Succinic, fumaric, and quinic acids are wide spread, tartaric acid was found in carrots, lettuce, endives, chicory, and celery. Other acids such as malonic, shikimic, and t-aconitic acids occurred sporadically. Lactic acid which was determined by two other methods was not detected in any vegetable species.

Acids↗
PubMed1984

[Occurrence of chlorogenic acids in potatoes].

Ten varieties of potato cultivated under the same conditions were analyzed for the occurrence of chlorogenic acids by high performance liquid chromatography. 3-O-caffeoylquinic acid (n-chlorogenic acid) is the predominant compound with 22-71 ppm, (on average of 41 ppm) depending on variety. 4-O-caffeoylquinic acid (phi 11 ppm), 5-O-caffeoylquinic acid (phi 7 ppm), 3,4-dicaffeoylquine acid (phi 3 ppm), and at times 3,5-dicaffeoylquinic acid (in traces) were also demonstrated. Caffeic acid compounds are not distributed uniformly in the potato tuber. They occur in strongly decreasing concentration from the outer sections to the inner ones. About 50% of these compounds are located in the potato peel and the adjoining tissue.

Chemical Phenomena↗
PubMed1984

Specific antibody response after in vivo antigenic stimulation in systemic lupus erythematosus.

Several in vitro studies have demonstrated a polyclonal B cell response to antigenic stimulation in patients with systemic lupus erythematosus (SLE). To determine if this polyclonal response occurs in vivo, 18 patients with SLE were antigenically stimulated with the pneumococcal vaccine Pneumovax . Mean antibody response to immunization was the same in SLE and normal control subjects. Although elevated antibody levels to several viruses were present in SLE subjects preimmunization, these levels did not change postimmunization. Total immunoglobulin levels, immune complex levels, and antiblood group B antibody levels did not change in SLE patients after immunization. Antiblood group A titers rose in both SLE patients and normals due to a media contaminant in the Pneumovax . Thus, SLE patients appear to have a specific antibody response to antigenic stimulation with pneumococcal polysaccharide. Polyclonal activation as seen in vitro in SLE may be more restricted in vivo.

Adult↗
PubMed1983

[Hydroxycinnamic acid esters in brassicaceous vegetables and garden cress].

The esters of caffeic, p-coumaric and ferulic acid with glucose or quinic acid and sinapoylglucose were determined in cauliflower, kale, Brussel sprouts, red, white, Savoy and Chinese cabbage and in garden cress by two different HPLC methods with gradient elution. In addition the occurrence of sinapin (sinapoylcholin) was checked. The pattern of hydroxycinamic acid esters in the Brassica species varied appreciably. In garden cress besides sinapin only sinapoylglucose was found. Sinapoylglucose is dominating in the group of glucose esters besides minor amounts of feruloylglucose. The 5-isomers of quinic acid esters, with neochlorogenic acid (5-caffeoylquinic acid) as the main compound, are dominating among the quinic acid esters. Considering the 3- and 4-isomers of quinic acid esters only 3- and 4-caffeoylquinic acids were determined in lower concentrations. Sinapoylquinic acid could never be recognized. Sinapin was determined in the Brassica species only in few cases in traces.

Brassica↗