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Biomedical subjects

E Andersen

Publications and source records attributed to E Andersen.

At least 145 records · Page 8Linked to original sources
PubMed1983

Dorsal raphe stimulation reduces responses of parafascicular neurons to noxious stimulation.

Spontaneous activity, responses to noxious stimulation and response to electrical stimulation of the dorsal raphe were recorded extracellularly from single units in the parafascicularis (PF) nucleus in the rat. Three types of spontaneous activity were found: 'slow' firing units (1-10 spikes/sec), 'bursting' units (bursts of 2-5 spikes/10-20 msec, bursts repeat every 1-2 sec), and 'fast' firing units (15-40 spikes/sec). Noxious stimulation increased the firing rate of 63% of the slow cells and 87% of the bursting cells, while the fast firing units did not respond. Dorsal raphe (DR) stimulation decreased the firing rates of both the slow and bursting PF cells only. The degree of suppression of PF units was directly related to the frequency and intensity of the DR stimulation. When the noxious stimulus was combined with DR stimulation, DR stimulation inhibited the increase in firing rate caused by the noxious stimulus. The firing rate during combined DR stimulation and noxious stimulation averaged 51% of that during the noxious stimulation alone. In several units, DR stimulation had no effect on spontaneous activity when applied alone but did decrease the effects of noxious stimulation when applied simultaneously. The results indicate that in addition to other possible mechanisms, the DR may affect responses to noxious stimuli via an ascending modulation pathway to the parafascicularis nucleus in the thalamus.

Animals↗
PubMed1983

Plasmapheresis in the treatment of psoriasis. A controlled clinical study.

Six patients with long-standing, moderately active plaque/nummular psoriasis were treated with either plasmapheresis or sham-plasmapheresis once weekly for 7 weeks in a double-blind controlled trial. No difference was found between active treatment and placebo. The marginal effect, which might be demonstrated by a larger study, is too small to justify this expensive modality of treatment.

Adult↗
PubMed1983

Extrahypothalamic brain luteinizing hormone: characterization by radioimmunoassay, chromatography, radioligand assay and bioassay.

We have recently reported that luteinizing hormone (LH) is present in the hypothalamus of rats. It has chromatographic and biologic characteristics similar to pituitary LH. In this report we focus on extrahypothalamic LH that is widely distributed in the rodent central nervous system. This material has a chromatographic profile similar to that of pituitary LH. Serial dilution of this material is parallel with dilutions of rat pituitary LH in the immunoassay. Brain extracts are active in the testis LH radioligand receptor assay and in the rat interstitial cell testosterone secretion bioassay. Prior incubation of extract with LH antibody significantly attenuated both of these activities. Thus, extrahypothalamic LH has immunologic, chromatographic, and biologic characteristics similar to hypothalamic and pituitary LH.

Animals↗
PubMed1983

Electrophysiological evidence of concurrent dorsal raphe input to caudate, septum, habenula, thalamus hippocampus, cerebellum and olfactory bulb.

Field potentials evoked by electrical stimulation of the dorsal raphe nucleus (DR) were recorded in eight forebrain structures in the rat. The areas were chosen chiefly for their anatomical connections to the DR and included the olfactory bulb (OB), caudate nucleus (CN), lateral septum (Spt), lateral habenula (Hb), parafascicularis (PF), ventral thalamus (VT), hippocampus-CA1 (Hipp), and cerebellum (CB). DR stimulation evoked an initial biphasic positive-negative wave form at similar latencies in each of the eight structures. A later positive-negative-positive wave was evoked in only six structures: CN, Spt, Hb, PF, VT, and Hipp. The amplitudes and latencies of the peaks of the later wave forms varied among structures. A depth profile recording procedure created by moving the DR stimulating electrode showed that the responses in the remote structures occurred only when the stimulating electrode was located in the DR. Bursting the DR at 20 Hz for 5-20 min caused a decrease in all components of the response. The evoked potential amplitude returned to baseline levels 5-30 min after cessation of stimulation. The results indicates that the dorsal raphe has a concurrent input to many areas of the brain receiving 5HT afferents and that DR stimulation can modulate the neuronal activity in these regions.

Animals↗
PubMed1982

Partial Turner's syndrome in four girls with Xq duplication and Xp deficiency.

Four girls with some clinical symptoms of Turner's syndrome had Xq duplication and Xp deficiency, their karyotypes being 46,X,dup(X)(p113;q11), 46,X,dup(X)(p212;q211), 46,X,dup(X)(p225;q13), and 46,X,dup(X)(p222;q213). No mosaicism was found. The major clinical findings, short stature, lack of pterygium colli, and no continuous gamete production, are compared with those in three previously published cases.

Adolescent↗
PubMed1982

Monocytotoxic antibodies after bone marrow transplantation in aplastic anemia.

Pre- and post transplant sera from 51 cases of bone marrow transplants performed for severe aplastic anemia were tested on monocytes (M) and corresponding B cells (B) from a panel of unrelated donors. One-third of the sera were cytotoxic for B and M either from different or from the same individuals, while 45% reacted only to M and appeared to recognize non-HLA M-associated antigens. No significant reaction to endothelial cells was obtained from these sera. The subsequent clinical course was not associated with any reaction pattern of pre-transplant sera. There was a significant relationship between rejection and the development of M antibodies after grafting, but since these were also found in many other patients without rejection, their occurrence has no predictive value for an individual patient.

Anemia, Aplastic↗
PubMed1982

Dorsal raphe nucleus modulates sensory evoked responses in caudate and septum.

The dorsal raphe nucleus (DR) was examined for its possible modulatory effects on sensory input to the caudate nucleus (CN) and lateral septum (Spt) in freely behaving rats. Three types of DR stimulation were tested for their effects on sensory evoked responses: (1) a single pulse of electrical stimulation of the DR prior to each sensory stimulus, (2) a 5-20 min burst of 20 Hz stimulation of the DR prior to sensory stimulation, and (3) a combination of the single pulse and the 5-20 min burst (20 Hz) stimulation of the DR prior to the sensory stimulation. Each of the three forms of DR stimulation caused a decrease in the amplitudes of the sensory-evoked responses recorded from the CN and Spt. Combination of DR stimulation caused stronger (summation) attenuation of the sensory responses. Thus, DR was shown to affect sensory input recorded in CN and Spt.

Animals↗
PubMed1982

The role of temporal factors in auditory perception of consonants and vowels. A study of different age groups.

Two series of speech identification tests were conducted in different age groups, the first test consisting of 11 synthetic speech stimuli varying in vowel length, the second test being composed of 30 natural speech stimuli varying in length of the initial consonant. Categorical perception of different phonemes was demonstrated in both experiments in all age groups. Persons more than 65 years of age showed significantly lower response percentages in both tests than did younger subjects. In the test where natural speech stimuli were used, boundaries of phoneme-category shift were dislocated in the older when compared with results of the younger subjects. Furthermore, speech discrimination was poorer in monaural than in binaural listening condition in the groups of more than 65-year-old persons with signs of age-induced sensorineural hearing loss; in this age group women showed clearly better results than men. These differences could not be demonstrated in the younger age groups.

Adolescent↗
PubMed1982

The effect of age and hearing loss on the identification of synthetic /b, d, g/-stimuli.

A series of speech identification tests using 15 synthetic consonant-vowel syllables with variations in second and third formant transitions were conducted in different age groups with normal hearing and a group of older subjects with a sensorineural hearing loss. Varying degree of categorical perception of three distinct phoneme categories /b, d, g/ was observed in all groups. Responses were depending on start frequency and gliding direction of second and third formant transitions. In the group of 60-80-year-old persons with a hearing loss response percentages were significantly lower and error frequency high. Furthermore, category shift boundaries changed as compared with the group of 20-40 years old. Results in a group of children age 8-15 years, were rather similar to those in the 20-40-year-old group. Both age and age-induced sensorineural hearing loss seemed to influence elderly people's ability to identity the synthetic speech stimuli.

Adolescent↗
PubMed1981

Macular function in typical and reticular retinoschisis.

Fifty-three patients with typical and reticular degenerative retinoschisis were evaluated. They demonstrated a corrected visual acuity of 20/20 except when some independent and unrelated ophthalmic condition was present. With a special protocol of test procedures, macular function in nine degenerative retinoschisis patients was found not significantly different from macular function in nine control patients. Macular function prognosis associated with degenerative retinoschisis is favorable, and implications for differential diagnosis are presented.

Aged↗