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Biomedical subjects

B Suhr

Publications and source records attributed to B Suhr.

15 recordsLinked to original sources
PubMed2000

Changes of the neurotransmitter serotonin but not of hormones during short time music perception.

We studied the impact of the perception of pleasant and unpleasant music, as rated by healthy subjects with a psychometric scale, on the hormones prolactin and ACTH. In addition, the neurotransmitter serotonin (5-HT) was studied using the platelet model for central neurotransmission of 5-HT. We did not observe any significant changes of prolactin and ACTH during the perception of different kinds of music. The 5-HT content of platelets, however, was higher during the perception of pleasant music as compared to the perception of unpleasant music indicating an increased release of 5-HT during unpleasant music (748 ng/10(9) platelets vs. 699 ng/10(9) platelets; p<0.014). The difference of the 5-HT level was significantly correlated to the score of unpleasantness as rated by the subjects. Our data suggest that perception of unpleasant music induces increased release and decreased peripheral and possibly also central intracellular content of 5-HT.

Adrenocorticotropic Hormone↗
PubMed2000

The impact of HIV infection on primary headache. Unexpected findings from retrospective, cross-sectional, and prospective analyses.

Headache is one of the most important factors influencing the quality of life in patients infected with the human immunodeficiency virus type 1 (HIV). However, only symptomatic headache but not changes or primary headache types during HIV infection have been studied to date. Therefore, we aimed to determine the impact of an HIV infection on frequency and semiology of different primary headache types. Patients with confirmed HIV type 1 infection underwent a neurological examination, neuroimaging or EEG, and a standardized interview. Time pattern and symptoms of headaches (cross-sectional analysis), changes of headaches preexisting to their infection (longitudinal retrospective analysis), and changes of primary headaches during a 2-year follow-up (longitudinal prospective analysis) were evaluated as were the correlations between these headache patterns and different markers of HIV infection. One hundred thirty-one consecutive HIV-infected patients without evidence of a cerebral manifestation except mild encephalopathy were enrolled. The point prevalence of migraine was 16.0% (confidence interval (CI) 10.1-25.4%), of headache with a semiology of tension-type headache 45.8% (CI 33.7-62.2%), and of other headache types 6.1% (CI 3.0-12.5%). During the natural course of infection, the migraine frequency significantly decreased in the retrospective and in the prospective analyses, whereas the frequency of the headache with a semiology of tension-type headache significantly increased in all three analyses. In 20% of all patients, the tension-type headache could be considered as symptomatic due to the infection but not due to focal or general cerebral lesions. Changes of primary headache were significantly associated with different stages of the infection and with the presence of mild encephalopathy but not with antiretroviral treatment or CD4 cell count. HIV infection seems to be associated with a progressive decrease in migraine frequency and intensity which probably is related to the immunological state of the patients. Tension-type headache becomes more frequent during HIV infection. However, this can in part be related to secondary headache caused by the HIV in less than 50% of patients with tension-type headache. The progressing immunological deficiency of HIV-infected patients seems to influence pain processing of primary headache types in different ways.

Adult↗
PubMed1999

Cognitive processing is involved in cluster headache but not in chronic paroxysmal hemicrania.

BACKGROUND: Cognitive processing in migraine is characterized by a loss of habituation during the interval and increased latencies in an attack. No studies are available on event-related potentials (ERPs) in cluster headache or chronic paroxysmal hemicrania. OBJECTIVE: To determine the involvement of cognitive processing in cluster headache and chronic paroxysmal hemicrania as measured by ERPs. METHODS: Visually evoked ERPs were measured in 50 patients with episodic cluster headache, 11 patients with chronic cluster headache, and 12 patients with chronic paroxysmal hemicrania. Measurements were performed in the cluster period outside an attack with and without prophylactic medication and not in the cluster period. RESULTS: Latencies of the endogenous ERP components were significantly increased during the cluster period as compared with outside the cluster period and with healthy subjects. In chronic cluster headache, latencies of both endogenous and exogenous components were increased. Medication with prophylactic drugs normalized the ERP latencies in episodic cluster headache; in chronic cluster headache, ERP latencies were decreased without complete normalization. No changes of ERP latencies and amplitudes could be observed in chronic paroxysmal hemicrania. A loss of cognitive habituation as it is known in migraine could not be observed in either cluster headache or chronic paroxysmal hemicrania. CONCLUSIONS: Our data suggest that central structures generating ERPs are involved in the pathophysiology of cluster headache during the cluster period but not outside the cluster period. This is in concordance with recent neuroimaging findings on the central role of the hypothalamus and the right frontal cortex in cluster headache and supports the hypothesis of a central origin of cluster headache. Furthermore, the data suggest that cluster headache and chronic paroxysmal hemicrania are distinct entities.

Adult↗
PubMed1999

A retrospective long-term analysis of the epidemiology and features of drug-induced headache.

Drug-induced headache is well known to result from the abuse of compounds taken for the treatment of primary headache. The features of drug-induced headache depend on various features including the availability of drugs, the regional health system, and psychogenic factors of the patients. We performed a retrospective study on a series of 257 consecutive German patients presenting with drug-induced headache during the period 1983-1996. Our aim study was to evaluate the demographic features, the frequency of various drugs used, in particular of ergotamine derivates, and changes in these features during the study period. The frequency of drug-induced headache among all headache patients was 8%, with a female preponderance of 81%. Drug-induced headache occurred in all age groups, predominantly in migraine patients (35%). The mean number of substances used was 2.7, mainly, acetaminophen (47.9%), ergotamine tartrate (45%), and combined analgesics (56%). We did not find a significant difference between the associations with ergotamine tartrate and dihydroergotamine, although the latter was taken less frequently. Comparing the early and late years of our study period, there were no changes in the frequency of drug-induced headache (8% versus 7%), although changes in the frequency of some drugs changed (barbiturates, ergotamine tartrate, and codeine intake decreased whereas nonsteroidal anti-inflationary drugs, combined analgesics, and sumatriptan intake increased). Our data suggest that changes in drug availability and the introduction of classification criteria and treatment recommendations did not have a major impact on the frequency of drug-induced headache.

Adult↗
PubMed1999

Dynamic changes of cognitive habituation and serotonin metabolism during the migraine interval.

Migraine patients show a specific cognitive processing with a loss of habituation in the interval and a normal habituation in the attack as measured by event-related potentials (ERPs). It is unknown whether the loss of habituation changes during the migraine interval or is a stable state. Serotonin (5HT) metabolism is involved in the pathophysiology of migraine and also in the generation of ERPs. We enrolled 14 patients with regular migraine attacks in order to measure visually evoked ERPs repetitively during the migraine interval and in the migraine attack. Cognitive habituation was evaluated by analysis of P3 latency. Platelet serotonin content and free serotonin plasma level were measured at the same time points. The loss of habituation increased continuously during the migraine interval and abruptly normalized in the migraine attack (p < 0.05, time series analysis). The platelet 5HT content decreased significantly in the migraine attack (p < 0.03) and was at its maximum in the middle of the interval. The P3 latency was significantly increased in the attack (p < 0.01) and was significantly inversely correlated with the platelet 5HT content (r = -0.44, p < 0.001). Free 5HT plasma levels did not show any significant change. Our findings suggest that loss of cognitive habituation continuously increases during the migraine interval until its normalization in the migraine attack. This phenomenon cannot be attributed to serotonergic transmission. In patients with regular changes of cognitive habituation before the migraine attack, it might be possible to predict the attack by analysing ERPs.

Adult↗
PubMed1999

Drug-induced headache: long-term results of stationary versus ambulatory withdrawal therapy.

Drug-induced headache is a well-known complication of the treatment of primary headache disorders, and its successful management is only possible by withdrawal therapy. However, it is unknown whether ambulatory or stationary withdrawal is the therapy preferred. We conducted a prospective study on the outcome of stationary versus ambulatory withdrawal therapy in patients with drug-induced headache according to the International Headache Society criteria. Out of 257 patients with the diagnosis of drug-induced headache during the study period, 101 patients (41 after ambulatory and 60 after stationary withdrawal therapy) could be followed up for 5.9 +/- 4.0 years. The total relapse rate after successful withdrawal therapy was 20.8% (14.6% after ambulatory and 25.0% after stationary withdrawal therapy, p < 0.2). The main risk factors for a relapse were male sex (OR = 3.9, CI = 1.3-11.6), intake of combined analgesic drugs (OR = 3.8, CI = 1.4-10.3), administration of naturopathy (OR = 6.0, CI = 1.2-29.3), and a trend to tension-type headache as the primary headache disorder (OR = 1.9, CI = 0.6-53.0). Our data suggest that neither the method of withdrawal therapy nor the kind of analgesic and other antimigraine drugs has a major impact on the long-term result after successful withdrawal therapy. Patients with risk factors according to our findings should be informed and monitored regularly, and combined drugs should be avoided. Furthermore, our data suggest that there is a need for research on individual psychological and behavioral risk factors for relapse after successful withdrawal therapy in drug-induced headache.

Adult↗
PubMed1998

Influence of end-stage renal failure and hemodialysis on event-related potentials.

Chronic renal failure frequently causes uremic encephalopathy with impairment of different cognitive functions, but the pathophysiology of uremic encephalopathy is still unknown. We measured visually evoked event-related potentials (ERPs) in 33 neurologically asymptomatic patients before and after they underwent hemodialysis and compared their data with those of a strictly age-matched healthy control group. Before hemodialysis, the patients' P3 latency was significantly increased and P3 amplitude was significantly decreased as compared with that of the healthy control group. After hemodialysis, P3 latency of the patients showed a significant decrease (457+/-56 before and 438+/-54 ms after hemodialysis) and the P3 latency habituation during the ERP measurement was also significantly decreased. Patients with higher levels of blood urea nitrogen (BUN), creatinine, and uric acid performed better in ERP measurement than did patients with lower levels. Hemoglobin did not influence ERP latencies and amplitudes. Our data suggest that impaired cognitive processing can be disclosed by ERP even in neurologically asymptomatic chronic renal disease. Removal of uremic toxins by hemodialysis leads to an improvement in cognitive processing.

Adult↗
PubMed1997

Cognitive processing in primary headache: a study on event-related potentials.

BACKGROUND: There is experimental evidence for loss of cognitive habituation in migraine but not in other types of headache and not by visual event-related potentials (ERP). OBJECTIVE: Determining the latencies (msec) and amplitudes (microV) of ERP components and the differences of these values in a two-trial analysis representing the amount of cognitive habituation. PARTICIPANTS: Two hundred thirty-three patients with a headache diagnosis according to the criteria of the International Headache Society: migraine without aura (N = 77); migraine with aura (N = 31); cluster headache during period (N = 26); cluster headache during interval (N = 11); chronic paroxysmal hemicrania (N = 8); episodic tension-type headache (N = 33); ergotamine-induced headache (N = 47). Thirty age-matched healthy subjects served as a control group. METHODS: ERPs were evoked by a visual oddball paradigm consisting of 2 x 200 flashes of light (85% white light; 15% red light). Evaluation of ERP components was done separately for the first 200 and the second 200 stimuli as well as for the entire series of stimuli. RESULTS: We found an acceleration of the P3 latency during the second trial in migraine with and without aura, but not in the other headache types, and not in healthy controls. Ergotamine and sumatriptan abolished this loss of habituation in migraine patients. Increased ERP latencies as compared with healthy controls were present in patients with cluster headache, tension-type headache, ergotamine-induced headache, and migraine with aura, but not in migraine without aura. CONCLUSION: There is a loss of cognitive habituation in migraine, which may serve as a specific but not sensitive diagnostic tool. The pathophysiologies of migraine and cluster headache have a specific modifying property on cognitive processing reflected by a loss of cognitive habituation or an increased cognitive processing time. These effects can, in part, be counterbalanced by antimigraine medication.

Adolescent↗
PubMed1985

Specific antibodies elicited by antigen covalently linked to a synthetic adjuvant.

S-(2,3-Bis(palmitoyloxy)-(2RS)-propyl)-N-palmitoyl-(R)-cysteinyl-( S)-serine (Tripam-Cys-Ser), a synthetic analogue of the N-terminal part of bacterial lipoprotein, constitutes a potent B-lymphocyte activator, inducing mitosis and immunoglobulin production, and is an adjuvant of the humoral immune response. The product was covalently coupled to a nonimmunogenic oligopeptide, representing an extracytoplasmic sequence of the receptor for the epidermal growth factor (EGF-R amino acids 516-529: Asn-Leu-Leu-Glu-Gly-Glu-Pro-Arg-Glu-Phe-Val-Glu-Asn-Ser). The resulting conjugate was able to induce a specific antibody response 2 wk after a single i.p. administration in mice, as measured by ELISA assays. Controls performed by injecting either adjuvant or oligopeptide alone, or a mixture of both compounds, elicited only a marginal stimulation of the specific antibody response. The conjugate was also immunogenic in vitro. Synthetically derived lipopeptides, thus, constitute powerful agents for turning substances of low immunogenicity into potent immunogens, after conjugating them covalently to the adjuvants. This technique should have a wide application in the preparation of conventional and monoclonal antibodies, as well as for the design of synthetic vaccines.

Adjuvants, Immunologic↗
PubMed1985

[In vitro methods for testing of plant derived, bacterial and synthetic agents and toxins with the use of leukocyte primary cell cultures and cell lines].

In this article a variety of in vitro methods is presented to test bacterial, plant-derived and synthetic products on eukaryotic cells. These in vitro methods give a lot of valuable information and thus in some cases may substitute for animal experiments. The influence of plant-derived substances on the macromolecular cellular syntheses (RNA-, DNA- and protein syntheses) and on cell membranes (incorporation of oleate into membrane lecithin, histamine release, cell lysis) was investigated. The in vitro experiments were performed on primary leucocyte cultures with lima bean lectins, suzukacillin, trichotoxin, alamethicin, cianidanol, and beta-hydroxy-ethylrutoside. Also various cell activating compounds were used to test the stimulation of mitosis and the production of immunoglobulins in B-lymphocytes: lipopolysaccharide (endotoxin), lipoprotein, and the synthetic lipoprotein analogues tripalmitoyl pentapeptide (TPP) and tripalmitoyl cysteine (TPC). Moreover we studied the effects of these substances on the incorporation of unsaturated fatty acids into the cell membrane constituents. Plant-derived and synthetic metal-complexing agents and polyethyleneglycols were also tested for synergistic or inhibitory effects on mitogen activated primary cell cultures and lymphoid cell lines. In many cases, the conclusions from the in vitro experiments may be extended to predict the results of in vivo experiments. In some cases, in vitro results are definitive, therefore experiments with animals can be avoided.

Animals↗
PubMed1985

Synthetic lipopeptide analogs of bacterial lipoprotein are potent polyclonal activators for murine B lymphocytes.

The lipoprotein from the outer membrane of Escherichia coli and other Enterobacteriaceae is a potent polyclonal activator for B lymphocytes. To determine the molecular structure responsible for the biologic activity of lipoprotein, a well-defined series of analogs of its N-terminal part was synthesized: S-(2,3-bis(palmitoyloxy)-(2-RS)-propyl)-N-palmitoyl-(R)-cysteine, -cysteine methyl ester, -cysteinyl-serine, -cysteinyl-seryl-serine, -cysteinyl-seryl-seryl-asparagine, and -cysteinyl-seryl-seryl-asparaginyl-alanine. All compounds were tested for mitogenic activity toward spleen cells from BALB/c, LPS-non-responder C3H/HeJ, and congenitally athymic C3H/Tif/Bom/nu/nu mice, measuring the incorporation of [3H]thymidine into DNA. Lymphocyte activation was confirmed by determination of the incorporation of [3H]uridine into RNA and [3H]leucine into protein. The synthetic lipopeptides were also investigated for their ability to stimulate B lymphocytes into immunoglobulin secretion, as shown by a hemolytic plaque assay. Throughout our studies, the compounds carrying two to five amino acids exhibited strong stimulation activity toward B lymphocytes comparable to native lipoprotein. In contrast, products containing only one amino acid, cysteine or cysteine methyl ester, were only marginally active, indicating that to obtain full biologic activity the presence of the hydrophilic dipeptide structure is necessary. All compounds exhibited only a marginal effect on thymocytes. Thus, a series of defined synthetic fragments of a bacterial outer membrane component exhibits a pronounced mitogenic and polyclonally stimulating activity towards B lymphocytes. The substances will be valuable tools for more detailed investigations on the molecular mechanisms of B cell activation.

Animals↗
PubMedDate not supplied

Sumatriptan and ergotamine overuse and drug-induced headache: a clinicoepidemiologic study.

Drug-induced headache, particularly ergotamine-induced headache, is a common problem in migraine treatment. Some case reports suggest that even the new serotonergic antimigraine drugs such as sumatriptan can lead to overuse and subsequent drug-induced headache. We performed a controlled study to identify the rate of sumatriptan overuse and sumatriptan-induced headache and compared it to the rate of ergotamine overuse and ergotamine-induced headache. Two thousand sixty-five consecutive heachache patients, all experienced in intake of sumatriptan (n = 631) or ergotamine (n = 620), were enrolled over a three-year study period. The rates of overuse and drug-induced headache and the clinical features of the subgroups were compared. Risk factors for sumatriptan overuse were identified. The rates of ergotamine and sumatriptan overuse were 14.2% and 3.5%, respectively (p < 0.001). Drug-induced headache could be found more frequently in cases of ergotamine overuse than in cases of sumatriptan overuse (68% versus 32%; p < 0.01). Development of sumatriptan overuse was most common in patients with previous drug-induced headache (68%), combined headache as the primary headache type (45%), and subcutaneous application of sumatriptan (45%). We conclude that sumatriptan intake can lead to overuse and subsequent drug-induced headache. The risk for overuse and drug-induced headache is significantly lower than in patients with ergotamine intake. This might be caused in part by the relatively short period of sumatriptan availability on the market. The new generation of serotonin-1B/D-receptor agonists in the treatment of headache should have a potential for overuse similar to that of traditional headache drugs.

Adult↗