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Biomedical subjects

J Bergmann

Publications and source records attributed to J Bergmann.

At least 55 records · Page 3Linked to original sources
PubMed1986

Neurotoxicity assessment of O-ethyl-O'-(2-diisopropylaminoethyl) methylphosphonite (QL) in hens.

O-ethyl-O'-(2-diisopropylaminoethyl) methylphosphonite (QL), an intermediate in the formation of ethyl S-2-diisopropylaminoethyl methylphosphonothiolate, was evaluated for neurotoxicity in the adult hen. Birds were given a single oral dose of QL ranging from 635 to 6080 mg kg-1. The QL-treated hens were observed for up to 24 h after dosing for acute toxicologic effects and over a 24 d post-dose period for evaluation of delayed neurotoxicity. The oral LD50 in hens is 1186 mg kg-1. Neurologic dysfunction, as evidenced by motor incapacitation, was observed at 6 days and thereafter after treatment with QL. Neurotoxic esterase (NTE) activity was not inhibited at 24 h after exposure to compound. Neural damage, multifocal in nature, was noted in the peripheral nervous system of QL-treated hens at dose levels greater than or equal to 635 mg kg-1, oral dose. These findings indicate neural damage tendencies following QL exposure.

Animals↗
PubMed1985

[Synthesis of cyclic and cyclically branched tachykinin partial sequences. 1. Synthesis of the homodet-cyclic eledoisin(6-11)-hexapeptide].

Ala-Phe-Ile-Gly-Leu-Met has been disengaged by cyclization of H-Leu-Met-Ala-Phe-Ile-Gly-OH by means of dicyclohexylcarbodiimide/N-Hydroxysuccinimide or the adequate p-nitrophenylester. Acc. to various strategic variants, the design of the linear precursor has been performed by condensation of the segments of Boc-Leu-Met-OH and H-Ala-Phe-Ile-Gly-OH. The resulting cyclo-[Eledoisin(6-11)-Hexapeptide] has in a clearly separated range of dose dual agonistic and antagonistic effects at the guinea-pig ileum.

Acetylcholine↗
PubMed1985

[Synthesis of cyclic and non-cyclic tachykinin partial sequences. 2. Synthesis of the homocyclic substance P(6-11) hexapeptide].

The authors describe the synthesis of Gln-Phe-Phe-Gly-Leu-Met by cyclization of H-Leu-Met-Gln-Phe-Phe-Gly using three different methods. The linear sequence was obtained by a (2+4)-segment condensation. The resulting cyclopeptide showed only a small kinin activity on isolated guinea pig ileum compared to substance P, but it is a full agonist.

Amino Acid Sequence↗
PubMed1984

Dental health status and attitudes to dental care in families participating in a Danish fluoride tablet program.

The caries experience and dental fluorosis of 84 Danish children, who had used fluoride tablets for 1-4 yr in the period 1976-80, were compared with those of a group matching in sex, age, place of living, and socioeconomic status. The average age of the children at the time of examination was 5.8 yr. A recording of mothers' attitudes to dental care, knowledge about tooth brushing, attitudes to candy, and number of teeth in the maxilla showed no difference between the fluoride tablet group and the non-users' group. Moreover, there was no significant difference between the two groups with respect to dental caries. The findings are discussed in relation to recent reports on the decline of dental caries resulting from widespread use of local administration of fluorides.

Adult↗
PubMed1984

[Clinical experimental test and equilibrimetric measurements of the therapeutic action of a homeopathic drug consisting of ambra, cocculus, Conium and mineral oil in the diagnosis of vertigo and nausea].

This paper presents a study by means of a modern neurotological technique for investigating the action and the site of action of an antivertiginous drug. The sensory motor tests are able to discriminate the sites of the lesions in the equilibrium regulating system, i.e., peripheral vestibular system, lower brainstem regulating system, upper brainstem nystagmus generating system and supratentorial system. Acoustic brainstem evoked potentials add information. A sample of 40 vertigo and nausea patients was treated by a combined drug, containing cocculus D4 210 mg, conium D3 30 mg, ambra D6 30 mg, mineral oil D8 30 mg (Vertigo-heel). The patients received 3 tablets 3 times per day during 14 days. An initial investigation was performed just before starting the treatment. A second directly followed the therapy. By subjective self-rating 57.5% of the patients reported on an improvement after the intake of Vertigoheel. Statistical evaluations showed that the different vertigo and nausea symptoms as well as the trigger mechanisms of vertigo and nausea (i.e. getting up, turning the head or gazing aside), highly significantly improved due to the therapy. The objective sensory motor tests showed a highly significant improvement in the monaural caloric butterfly chart as well as in the vestibulospinal head and body sway. The site of the action of Vertigoheel is in the brainstem and the Medulla oblongata, especially the middle longitudinal fascicle (MLF). The localisation in this area can be stressed by the investigation with acoustically brainstem evoked potentials (ABEP).(ABSTRACT TRUNCATED AT 250 WORDS)

Antiemetics↗
PubMed1983

[Synergistic receptor subtypes: an explanation for reserve receptors and for different intrinsic activities of full and partial agonists. Studies on the effect of substance P and its analogs on guinea pig ileum].

The contractile response of guinea-pig ileum to substance P consists of an initial rapid phasic contraction followed by a lower tonic contraction. Both contraction phases can be changed independently of each other. Substance P analogues differ in their ability to induce the phasic and tonic contraction. The structure-activity profile (calculated from ED50) for C-terminal substance P fragments and acylated analogues differ from the structure-affinity profile (calculated from the dissociation constant which was estimated by the desensitization method). These results suggest the possible existence of two substance P receptor subtypes that have different affinities for substance P analogues. Both are coupled with an increase in cytoplasmatic Ca++ and with contraction. Stimulation of SPCa-i (SPCa-influx) receptors seems to open calcium channels in the smooth muscle membrane while SPCa-r (SPCa-release) receptor stimulation seems to release membraneous Ca++. Such synergistic subreceptors could be the cause of the pharmacological phenomenon of spare receptors. If this is the case, then the intrinsic activity would reflect differences in the affinity or the selectivity of analogues for these subreceptors. Partial agonists activate only one synergistic receptor subtype or activate synergistic as well as antagonistic subtypes with similar affinities. Mixed agonist-antagonists are agonists of one, and antagonists of the other synergistic receptor subtype. Organ-selective stimulatory effects of certain analogues can be explained by the various subtypes being distributed in a different fashion between different organs. The possibility to detect the presence of different receptor subtypes from the shift of dose response curves by irreversible antagonists and from the shift of binding curves by GTP and ions is discussed.

Acetylcholine↗
PubMed1981

Contractile response of longitudinal and circular smooth muscles of guinea pig stomach and ileum to substance P.

The mechanical activity of longitudinal and circular smooth muscle preparations from fundus, corpus, and antrum of guinea pig stomach and distal ileum of guinea pig were recorded and the effect of substance P (SP) was measured. In physiological concentrations (10(-13) - 10(-7) mol/l) SP activates the tone of circular muscle strips from fundus and corpus of guinea pig stomach. Quite opposite is the situation with respect to the SP tonic activation in the muscle layers of guinea pig ileum. Here SP activates only the tone of longitudinal muscle layers. In these concentrations SP induces no or only very small contractile response in longitudinal muscle strips of fundus and corpus and in circular muscle preparations of distal ileum. The greater sensitivity to SP appears to result for the longitudinal muscle layer of ileum followed by the circular layer of fundus and corpus.

Animals↗
PubMed1978

Effect of substance P on mechanical and myoelectrical activities of stomach and small intestines in conscious dog.

The effect of Substance P (SP) on the intestine in situ of the dog was investigated. Five female dogs were used. At the same time, mechanographic recordings, using balloon kymography, were taken, while the myoelectric activity was recorded by means of electrography. Differences in SP action on the mechanogram and electromyogram of the stomach and the small intestines were reflected in the following phenomena: (a) SP in the doses used was less active on the ileum than on the stomach; (b) SP increased basal tonus but inhibited peristaltic contraction; (c) SP acted predominantly on spike discharges in the electromyogram. These results are likely to support the assumption that SP acts as a physiological modulator of smooth muscle activity.

Animals↗