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Biomedical subjects

U Wesselmann

Publications and source records attributed to U Wesselmann.

35 records · Page 2Linked to original sources
PubMed1998

Paraneoplastic pemphigus treated with dexamethasone/ cyclophosphamide pulse therapy.

Paraneoplastic pemphigus (PNP) is an autoimmune, mucocutaneous bullous disease associated with underlying malignancies. We report a patient with Waldenström's macroglobulinemia who developed clinical, histological and immunopathological features typical of PNP. The patient was treated twice with i.v. dexamethasone and cyclophosphamide pulse therapy (day 1: cyclophosphamide 500 mg i.v.; day 1-3: dexamethasone 100 mg i.v.) at 3-week intervals. Therapy was continued with oral cyclophosphamide (50 mg/d). Two weeks after initiation of treatment, significant improvement of the cutaneous and mucosal lesions was noted. The therapy also had beneficial effects on the macroglobulinemia in terms of a marked reduction of the IgM lambda serum level. Three months after the second pulse, severe stomatitis recurred but the patient rejected any further systemic therapy. The initial response of the usually recalcitrant mucosal and skin lesions of PNP makes dexamethasone/cyclophosphamide pulse therapy an interesting therapeutic option.

Administration, Oral↗
PubMed1996

[Pain syndromes in AIDS].

Pain is a major, but largely neglected problem in AIDS patients. The aim of this article is to review the etiology of pain manifestations in AIDS patients in different organ systems and to discuss appropriate treatment strategies. The most common pain symptoms in AIDS patients are headache, oral cavity pain, dysphagia and adynophagia, chest pain, abdominal pain and pain related to peripheral neuropathy. Symptomatic pain treatment should be started while diagnostic work-up is still in progress, so that the patient does not suffer. If etiological treatment is possible, specific treatment pain treatment tapered as tolerated. If etiological treatment is not possible, symptomatic pain treatment should be continued. In view of the multiple organs involved in the presentation of AIDS requiring multiple drugs, careful attention to side effects, contraindications and drug interactions is warranted, when administering pain medications. Fear of the complexity of these issues should, however, not prevent effective pain management for these patients, who suffer from a fatal disease. A multidisciplinary approach to pain in AIDS patients, similar to the approach in patients with cancer, is desirable.

Acquired Immunodeficiency Syndrome↗
PubMed1996

The dynias.

The "dynias" are a group of chronic, focal pain syndromes with a predilection for the orocervical and urogenital regions. They include glossodynia, carotidynia, vulvodynia, orchidynia, prostatodynia, coccygodynia, and proctodynia. In some cases, the dynias occur secondarily, but more often, despite an exhaustive evaluation, no etiology is found and in these remaining cases, the cause of the pain remains enigmatic. The controversy that surrounds this group of disorders, which ranges from questioning their existence to suggesting that they are purely psychosomatic, is counterbalanced by an extensive literature attesting to their organicity. The approach to the patient begins with acknowledging that the symptom is well described, searching for a secondary cause, and performing a careful psychologic assessment. Treatment is empirical and patients can often be helped with medications used to treat neuropathic pain, all the while providing psychologic support and exercising caution toward invasive and irreversible therapeutic procedures.

Adult↗
PubMed1996

Galactorrhea and hyperprolactinemia in schizophrenic patients on neuroleptics: frequency and etiology.

The frequency of galactorrhea and the subjective response to it were investigated in 150 schizophrenic patients. The incidence rate was 14% and the prevalence rate 19%. The latency periods between start of neuroleptic medication and manifestation of galactorrhea were subject to substantial scatter, as were the prolactin values. Patients who had undergone neuroleptic relapse prevention prior to the index episode and/or had been pregnant were affected significantly more frequently by galactorrhea.

Adult↗
PubMed1995

Galactorrhea: subjective response by schizophrenic patients.

The frequency of galactorrhea and the subjective response to it were investigated in 150 schizophrenic patients. The incidence rate was 14% and the prevalence rate 19%. More than half the women experienced galactorrhea in connection with their femininity, with this side effect of neuroleptic therapy being rated more often as a positive effect, especially as a reinforcement of feminine identity or as an expression of the ability to conceive children. The overall response to galactorrhea was positive among 43% and negative among 20%, with the remaining patients tending towards indifference.

Adaptation, Psychological↗
PubMed1994

Laser effects on myelinated and nonmyelinated fibers in the rat peroneal nerve: a quantitative ultrastructural analysis.

We have recently shown that Nd:YAG laser irradiation of rat peripheral nerve differentially impairs action potential transmission in small, slowly conducting sensory fibers compared to fast conducting afferents. In addition, the number of small sensory neurons of the A-delta- and C-fiber group labeled with HRP is significantly reduced after laser irradiation, while the number of labeled large sensory neurons and motoneurons was not affected. To further evaluate this laser-induced injury, we examined three distinct regions of the laser-irradiated rat peroneal nerve using ultrastructural morphometric methods. These regions were the site of laser irradiation and zones 10 mm proximal and 5 mm distal to the injury. The contralateral nerve was sham treated. Our results indicate that for the small nonmyelinated fibers, there was a significant increase in both mean fiber size and the number of microtubules per fiber, but a decrease in the number of neurofilaments. In contrast, the number of myelinated and nonmyelinated fibers is not significantly altered at 7 days following laser irradiation, and the mean diameter and frequency distribution of myelinated nerve fibers was unchanged. This study demonstrates that selective functional alterations in laser-irradiated nerves (nerve conduction velocity, HRP transport properties) are accompanied by ultrastructural changes of axonal organelles in nonmyelinated fibers. Nd:YAG laser light might ultimately prove to be a powerful tool to selectively alter functional properties in small, slowly conducting afferent fibers, without causing degeneration at the ultrastructural level at the site of irradiation. We hypothesize further that the laser-induced functional alterations might be related to differential thermally mediated changes.

Animals↗
PubMed1993

Retrograde horseradish peroxidase transport in motor axons after Nd:YAG laser irradiation of the tibial nerve in rats.

We have recently demonstrated that the number of small sensory neurons of the A-delta- and C-fiber group in lumbar dorsal root ganglia labeled with horseradish peroxidase (HRP) is selectively decreased 7 days after Nd:YAG laser irradiation of the tibial nerve in the rat. In contrast, the number of large diameter sensory neurons was not affected by laser application. In an attempt to clarify the fate of motoneurons after laser irradiation of their peripheral axons, the numbers of lumbar motoneurons retrogradely labeled with HRP 7 days after Nd:YAG laser irradiation of the tibial nerve have been determined in rats. Our results show that the number of HRP-labeled motoneurons in lumbar segments L6 to L3 is not altered to a significant extent after laser irradiation of their peripheral axons (laser-treated side, 767 +/- 10 cells vs control side, 808 +/- 19; n = 5, mean +/- SEM). In addition, no difference was detected in the mean value or the distribution of soma cross-sectional areas of labeled motoneurons on the laser-treated side and the control side. Specifically, the numbers of HRP-labeled small diameter motoneurons, which are presumably gamma in type and have a conduction velocity similar to sensory neurons of the A-delta group, were not affected by laser application. Possible mechanisms of the differential vulnerability of sensory neurons as compared to motoneurons of similar size are discussed.

Animals↗
PubMed1991

Selective decrease of small sensory neurons in lumbar dorsal root ganglia labeled with horseradish peroxidase after ND:YAG laser irradiation of the tibial nerve in the rat.

Recent electrophysiological evidence indicates that Q-switched Nd:YAG laser irradiation might have selective effects on neural impulse transmission in small slow conducting sensory nerve fibers as compared to large diameter afferents. In an attempt to clarify the ultimate fate of sensory neurons after laser application to their peripheral axons, we have used horseradish peroxidase (HRP) as a cell marker to retrogradely label sensory neurons innervating the distal hindlimb in the rat. Pulsed Nd:YAG laser light was applied to the tibial nerve at pulse energies of 70 or 80 mJ/pulse for 5 min in experimental rats. Seven days later HRP was applied to the left (laser-treated) and to the contralateral (untreated) tibial nerve proximal to the site of laser irradiation. In control animals the numbers of HRP-labeled dorsal root ganglion cells were not significantly different between the right and the left side. In contrast, after previous laser irradiation labeling was always less on the laser-treated side (2183 +/- 513 cells, mean +/- SEM) as compared to the untreated side (3937 +/- 225). Analysis of the dimensions of labeled cells suggested that the reduction of labeled cells on the laser-treated side was mainly due to a deficit in small sensory neurons. Since the conduction velocity of nerve fibers is related to the size of their somata, our histological data imply that laser light selectively affects retrograde transport mechanisms for HRP in slow conducting sensory nerve fibers.

Animals↗
PubMed1991

Differentiation of sympathetic neurones projecting in the hypogastric nerves in terms of their discharge patterns in cats.

1. Sympathetic neurones that project in the hypogastric nerves (HGNs) were analysed for their discharge patterns in anaesthetized cats. The activity of these neurones was recorded from their axons. Afferents from the pelvic organs (urinary bladder, colon, anal canal), and arterial baro-and chemoreceptors were stimulated. 150 postganglionic and nine preganglionic neurones were analysed. 2. The postganglionic neurones exhibited reflex patterns that were typical of visceral vasoconstrictor neurones and various types of motility-regulating neurones. Most motility-regulating neurones and all visceral vasoconstrictor neurones had ongoing activity. 3. Postganglionic motility-regulating neurones were not influenced by stimulation of arterial baro-and chemoreceptors, but showed distinctive reflexes on stimulation of afferents from pelvic organs. Three subgroups of motility-regulating neurones were identified: type 1 neurones (34% of the sample of postganglionic neurones) were excited from the urinary bladder and inhibited or not influenced from the colon. Type 2 neurones (14%) exhibited a reflex pattern reciprocal to that of the type 1 neurones. Anal motility-regulating neurones (8%) were only influenced from the anal canal. The most powerful reflexes in these types of motility-regulating neurones were elicited by mechanical stimulation of the anal mucosa. 4. Postganglionic visceral vasoconstrictor neurones (16% of the sample) were under powerful inhibitory control from the arterial baroreceptors and weakly excited by stimulation of arterial chemoreceptors. Visceral stimuli had little or no effect on most of these neurones. Some visceral vasoconstrictor neurones exhibited some overlap in their functional properties with motility-regulating neurones. 5. Twenty-eight per cent of our sample of postganglionic neurones showed no reflexes to the afferent stimuli used. About half of these neurones had on-going activity. 6. Nine preganglionic neurones with on-going activity were identified. Most of these neurones behaved like visceral vasoconstrictor or motility-regulating neurones. 7. This study shows that the majority of postganglionic neurones that project in the HGNs can be divided into the same functional types as the lumbar preganglionic neurones that project to the inferior mesenteric ganglion. The proportions of the different types of neurones are similar at pre- and postganglionic levels. Thus the centrally generated patterns of activity are most likely faithfully transmitted from the spinal cord to the target organs in the pelvic cavity in functionally separate pathways.

Anal Canal↗
PubMed1991

Effects of muscle fatigue on mechanically sensitive afferents of slow conduction velocity in the cat triceps surae.

1. Group III and IV muscle afferents have been shown to be sensitive to both mechanical stimuli and metabolic and thermal changes in muscle. To establish the potential role of slowly conducting muscle afferents in regulating motor output during fatigue, we recorded from mechanically sensitive group III and nonspindle group II afferents originating in the triceps surae in barbiturate-anesthetized cats. We evaluated the response of these afferents to tetanic muscle contraction, stretch, and surface pressure, before, during, and after fatigue. 2. Our results show that muscle fatigue both increases spontaneous discharge in these mechanically sensitive afferents and sensitizes their response to muscle stretch, surface pressure, and, in a few instances, muscle contraction. These fatigue-induced changes typically occurred after 5-10 min of submaximal fatiguing stimulation. 3. During recovery from muscle fatigue, several contraction-sensitive free nerve endings, which had become sensitized to contractions during fatigue, remained sensitized after 20-30 min of rest. 4. The results of this study provide support for the hypothesis that fatigue-induced excitation of slowly conducting afferents is significant in mediating fatigue-induced inhibition of motoneuron output. However, our finding that the discharge of many slowly conducting mechanoreceptor afferents declines during the initial phase of fatigue argues against a primary role for these afferents in mediating the initial decline in motoneuron rate that is so prominent in fatiguing maximum voluntary muscular contraction.

Afferent Pathways↗
PubMed1991

Effects of Q-switched Nd:YAG laser irradiation on neural impulse propagation: I. Spinal cord.

We studied the effect of irradiation with Q-switched Nd:YAG laser light (1064 nm) on spinal cord dorsal column and dorsolateral white matter in anesthetized rats. To evoke a synchronous sensory input, the sciatic nerve was stimulated electrically and the resulting evoked spinal cord potential (SCP) recorded from the dorsal columns of the ipsilateral side. The waveshape of the SCP showed three components: an early positive peak (P1), representing the responses of the most rapidly conducting fibers, followed by two negative peaks (N1 and N2), which are mainly due to synaptic effects of the volley on dorsal horn cells located in dorsal grey matter. Laser irradiation at 50 mJ/pulse and above resulted in severe reduction in the amplitudes of N1 and N2. In contrast, there was either no reduction at all or only a slight decrease in the amplitude of P1. The selective loss of the synaptic field might be mediated by impairment of synaptic transmission or by loss of high threshold fiber input to dorsal horn neurones. In either event it is likely that the mechanism of the differential effects of laser irradiation on the components of the electrically evoked SCP is at least in part photothermally mediated, since intracord temperatures during laser application greatly exceeded the physiological range.

Animals↗
PubMed1991

Effects of Q-switched Nd:YAG laser irradiation on neural impulse propagation: II. Dorsal roots and peripheral nerves.

We have studied the effects of Q-switched Nd:YAG laser irradiation on transmission of neural impulses in sensory nerve fibers in anesthetized rats and cats. Laser light was applied to dorsal roots (rat, cat) and to the sciatic nerve (rat) at increasing pulse energies ranging from 10 to 100 mJ/pulse for 5 minutes each. Compound action potentials recorded from dorsal roots and the sciatic nerve in response to high intensity electrical stimulation during laser application at increasing pulse energies showed a progressive preferential reduction of the slow late component of the electrically evoked response. Preliminary data from multifilament recordings from dorsal roots in cats demonstrated that conduction in small slow conducting fibers was blocked at lower laser pulse energies than in fibers with faster conduction velocities. These results imply, that laser light might have differential effects on slow versus fast conducting sensory nerve fibers. It is most likely that the preferential effect of laser irradiation on slow conducting fibers is mediated by photothermal mechanisms, since temperature increased substantially during laser application.

Action Potentials↗
PubMed1990

Suppression of clinical weakness in experimental autoimmune encephalomyelitis associated with weight changes, and post-decapitation convulsions after intracisternal-ventricular administration of 6-hydroxydopamine.

Selective depletion of central nervous system norepinephrine (NE) by the neurotoxin 6-hydroxydopamine (6-OHDA) in rats subsequently inoculated with myelin basic protein (MBP) and complete Freund's adjuvant (CFA) produced experimental autoimmune encephalomyelitis (EAE) without the usual expected degree of weakness. The preservation of strength occurred in spite of continued weight loss. Post-decapitation myoclonic convulsive kick latency and kick number, which are known to depend on spinal cord NE, agreed well with the degree of weakness through the clinical disease course. The only difference between EAE groups was that the stronger 6-OHDA pretreated EAE animals did not have an elevated pons-medulla NE compared to saline intracisternal-ventricular (i.c.v.) pretreated controls. We conclude that 6-OHDA can influence the clinical course of weakness by interfering with central noradrenergic activity independent of other features associated with disease in EAE. This effect of 6-OHDA may be exerted through alteration of the blood-spinal cord barrier function and/or central nervous system blood flow.

Animals↗
PubMed1988

Early effects of experimental diabetes on central catecholamine concentrations.

Six days after induction of diabetes norepinephrine (NE), 3,4-dihydroxyphenylalanine and dopamine concentrations were determined in spinal cord, cerebellum, pons/medulla oblongata and the remaining brain of diabetic rats. Only cerebellar NE levels were significantly increased by 21% compared to age-matched controls. This effect was not seen when diabetic rats received insulin replacement therapy. Fifty-two days after induction of diabetes cerebellar NE levels in diabetic rats were further increased (+37%), implying an enduring and progressive effect. The data show that even with a short period of uncontrolled diabetes central neurochemical alterations occur.

Animals↗
PubMed1987

Altered splenic catecholamine concentrations during experimental allergic encephalomyelitis.

Catecholamine concentrations of the spleen were studied with neurochemical techniques in rats injected with myelin basic protein to produce an experimental allergic encephalomyelitis (EAE). Thirteen to 14 days postinoculation the affected rats showed peak clinical signs of weakness, especially in the lower extremities. Resolution of the disease then progressed rapidly with full clinical recovery at day 21. Splenic concentrations of norepinephrine (NE), 3,4-dihydroxyphenylalanine (DOPA), epinephrine (EPI) and 3,4-dihyxroxyphenylethylamine (DA) were determined by HPLC with electrochemical detection. DOPA concentrations were significantly increased (+62%) while DA concentrations were decreased (-29%) in the EAE rats on day 14 postinoculation. NE and EPI concentrations tended to be elevated in the EAE group, but this was not statistically significant. No differences in splenic catecholamines were detected on day 7 and 52 postinoculation between EAE and control animals. These results indicate that changes in the metabolic pathways of splenic catecholamines occur at the peak of the clinical symptoms of EAE; the increase in DOPA and the decrease in DA concentrations suggest that the activity of DOPA-decarboxylase or its co-factor is altered.

Animals↗
PubMed1984

The effect of previous transection on quantitative estimates of the preganglionic neurones projecting in the cervical sympathetic trunk of the guinea-pig and the cat made by retrograde labelling of damaged axons by horseradish peroxidase.

The numbers of sympathetic preganglionic neurones in the upper thoracic spinal cord retrogradely labelled after application of horseradish peroxidase to the severed axons of the cervical sympathetic trunk have been determined in guinea-pigs and in cats. Neuronal counts were made on both sides of spinal segments C8 to T10 in control animals and in others in which the enzyme was applied 5-8 days after the left cervical sympathetic trunk had been transected. Labelling was not significantly different between sides of unoperated animals, but after previous cervical trunk section labelling was always less, by from 5 to 100% of that on the control side. The results were not significantly different if the application of horseradish peroxidase was made close to the original lesion or 1 cm more proximal along the nerve trunk. Analysis of the dimensions of labelled cells suggested that the deficit in labelling was greatest for small preganglionic neurones. These findings do not support an earlier report that retrograde labelling from regenerating axons is enhanced at this stage after axotomy, and the possible reasons for the discrepancy in results are discussed. It is suggested that labelling of cell bodies may not be restricted if intact axon sprouts are exposed to horseradish peroxidase. Reduced labelling from axons at the time of a second transection might, at least in part, be due to axon atrophy, emphasizing limitations to labelling when horseradish peroxidase is applied to severed axons of fine diameter. The high numbers and reproducibility of our control data enabled estimates to be made of the segmental distribution of the cell bodies or origin of the axons of the cervical sympathetic trunk in both species.

Animals↗