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R Dom

Publications and source records attributed to R Dom.

At least 73 records · Page 4Linked to original sources

Triamcinolone and prednisolone affect contractile properties and histopathology of rat diaphragm differently.

Diaphragm atrophy and weakness occur after administration of massive doses of corticosteroids for short periods. In the present study the effects of prolonged administration of moderate doses of fluorinated and nonfluorinated steroids were investigated on contractile properties and histopathology of rat diaphragm. 60 rats received saline, 1.0 mg/kg triamcinolone, or 1.25 or 5 mg/kg i.m. prednisolone daily for 4 wk. Respiratory and peripheral muscle mass increased similarly in control and both prednisolone groups, whereas triamcinolone caused severe muscle wasting. Maximal tetanic tension averaged 2.23 +/- 0.54 kg/cm2 (SD) in the control group. An increased number of diaphragmatic bundles in the 5-mg/kg prednisolone group generated maximal tetanic tensions < 2.0 kg/cm2 (P < 0.05). In addition, fatigability during the force-frequency protocol was most pronounced in this group (P < 0.05). In contrast, triamcinolone caused a prolonged half-relaxation time and a leftward shift of the force-frequency curve (P < 0.05). Histological examination of the diaphragm showed a normal pattern in the control and 1.25-mg/kg prednisolone group. Myogenic changes, however, were found in the 5-mg/kg prednisolone group and, more pronounced, in the triamcinolone group. Selective type IIb fiber atrophy was found in the latter group, but not in the prednisolone groups. In conclusion, triamcinolone induced type IIb fiber atrophy, resulting in reduced respiratory muscle strength and a leftward shift of the force-frequency curve. In contrast, 5 mg/kg prednisolone caused alterations in diaphragmatic contractile properties and histological changes without fiber atrophy.

Animals↗

Further evidence for myelinated as well as unmyelinated fibre damage in a rat model of neuropathic pain.

A mononeuropathy, produced by ligation of the sciatic nerve in rats, has recently been proposed as an animal model of experimental pain and pain-related disorders (hyperalgesia and allodynia). We investigated quantitatively the morphological changes in myelinated and unmyelinated fibres of the sciatic nerves 2 weeks after ligation in rats exhibiting allodynia to thermal stimulation. There was a marked reduction in the number of large myelinated fibres distal to the ligature (711 +/- 34 compared with 5315 +/- 230 in normal nerves). We also found a significant loss of small myelinated fibres (2429 +/- 109 compared with 3197 +/- 308 in normal nerves), the remaining fibres of this type showing pathological properties. Finally, ultrastructural evidence of damage to unmyelinated fibres was found. The typical pattern of large clusters of normal unmyelinated axons was no longer present within most regions of the nerve. There was a significant reduction in the size of the unmyelinated fibres (0.41 micron +/- 0.15 compared with 0.71 micron +/- 0.08 in normal nerves), together with a twofold increase in their number per cluster. Hypotheses about the mechanism of thermal allodynia in this pain model therefore must take into account the fact that all fibre classes show pathological changes.

Animals↗

Purulent meningitis due to aspergillosis in a patient with systemic lupus erythematosus.

We report a 39-year-old female patient with systemic lupus erythematosus under immunosuppressive therapy who developed persistent neutrophilic meningitis, for which no infectious agent could be identified. Intensifying the immunosuppressive therapy induced a short amelioration of the clinical picture. At autopsy, basal meningitis was found to be due to Aspergillus sp.

Adult↗

Pleuropulmonary changes during treatment of Parkinson's disease with a long-acting ergot derivative, cabergoline.

A patient with Parkinson's disease, initially treated with bromocriptine and subsequently with cabergoline, developed progressive pleuropulmonary abnormalities during the latter therapy. These lesions even worsened for some weeks after interruption of cabergoline, which may possibly be related to the prolonged action of this drug. Thus cabergoline may cause similar pleuropulmonary abnormalities to bromocriptine.

Bromocriptine↗

MR imaging of intracranial aspergilloma extending from the sphenoid sinus in an immunocompromised patient with multiple myeloma.

A case of fatal intracranial aspergillosis, extending from the sphenoid sinus via the orbit into the subarachnoid space of the optochiasmatic cistern and the cistern of the middle cerebral artery is presented in an immunosuppressed patient with multiple myeloma. Adequate treatment was not instituted and the patient died because the condition was not recognised and interpreted as a soft tissue extension of an orbital localization of myeloma. MRI, especially after intravenous injection of Gadolinium, depicted very accurately the extension of the disease, as defined at autopsy.

Aspergillosis↗

Zenker's diverticulum: is a myotomy of the cricopharyngeus useful? How long should it be?

In a series of 100 consecutive patients surgically treated for Zenker's diverticulum (ZD) biopsy specimens were taken at the level of the cricopharyngeal muscle in 62 patients and also at the level of the striated muscle wall of the cervical esophagus in 10 patients. Contractility, pathological enzymo- and immunohistochemical characteristics were studied in comparison with a group of 15 controls. Obvious pathological findings were noted in 95% of the ZD specimens as compared with the control specimens. These pathological changes, although somewhat less pronounced, were also documented in the biopsy specimens taken at the level of the striated cervical muscle wall. The findings were judged important enough to justify a long extramucosal myotomy of the cricopharyngeal muscle and cervical esophagus as an essential step in the treatment of ZD. The treatment of choice in this series was a diverticulopexy and a four to five centimeter long extramucosal myotomy, starting from the cricopharyngeal muscle and extending downwards into the striated muscle wall of the cervical esophagus. Excellent or very good results were obtained in 96% of the patients with respect to diverticulum-related symptoms.

Adult↗

Early-onset Alzheimer's disease in 2 large Belgian families.

Familial Alzheimer's disease (FAD) is a dominantly inherited condition that may present with an early onset, and myoclonus occurs frequently in the course of the disease. We report clinical and neuropathologic data on 2 large Belgian families with FAD in which we obtained 17 autopsies of the CNS. In family A, each of 11 autopsies had the typical neuropathologic features of Alzheimer's disease (AD), and there were a few cerebellar plaques in the molecular layer. In family B, in addition to the typical characteristics of AD in 6 autopsies, there were numerous amyloid plaques in the cortical cerebellar layers. In both families, we immunostained the amyloid deposits for the A4 protein, and they were negative for prion-associated protein immunoreactivity.

Adult↗

Globoid cell leukodystrophy: a family with both late-infantile and adult type.

We present a patient with adult-onset globoid cell leukodystrophy (GBL) who had almost complete deficiency of galactosylceramide beta-galactosidase. A brother of the index patient deteriorated neurologically and died at the age of 4, probably from the late-infantile form of the disease. In this family, two clinical types of GBL are probably different expressions of an identical genotype.

Adult↗

Growth properties and in vitro life span of Alzheimer disease and Down syndrome fibroblasts. A blind study.

A blind study was set up to examine the in vitro growth characteristics of skin fibroblasts from 2 individuals with and 9 at risk for familial Alzheimer disease, 4 individuals with sporadic Alzheimer disease, 18 with Down syndrome as well as 5 younger and 6 older controls. Several variables (biopsy size, number of explants, medium, passage procedure) were standardized. Two growth characteristics were examined quantitatively: (i) the actual in vitro replicating life span was determined by counting the number of cells plated the previous week at 500,000 cells/flask (cumulative population doublings); and (ii) the growth potential was examined by a colony size distribution assay. A difference from the age-matched controls in the growth characteristics of skin fibroblasts was only observed for two patients with and one older individual at risk for familial Alzheimer disease. The growth properties of skin fibroblast cultures from patients with sporadic Alzheimer disease or Down syndrome were not at variance with their age-matched controls. The decrease in the growth potential observed in the familial Alzheimer disease fibroblasts is however modest and needs confirmation. It is clear that the growth properties of skin fibroblasts, as examined in this study, do not provide a good marker for any form of Alzheimer disease, nor do they provide an appropriate in vitro system to study factors which may contribute to the etiopathogenesis of Alzheimer disease or Down syndrome.

Adult↗

Hemangioblastoma of the lateral ventricle.

A case of hemangioblastoma of the right lateral ventricle is presented. Only five other cases of intraventricular hemangioblastoma have been reported. The literature on supratentorial intraventricular hemangioblastoma is reviewed.

Adult↗

Suppression of the hindlimb flexor reflex by stimulation of the medial hypothalamus and thalamus in the rat.

Pentobarbital-anesthetized rats received electrical hindpaw stimulation every 10 s to elicit a maximal hindlimb withdrawal reflex. The integrated EMG response in the ipsilateral tibialis anterior was sampled by a computer which also controlled the timing of electrical stimuli applied to the brain. A suppression of the evoked flexor activity was obtained with currents below 0.05 mA for stimuli applied in the medial hypothalamic region. A second effective site was located in the paraventricular area of the thalamus. The suppression had an onset latency of 30 ms, increased over a period of 500 ms and was followed by a postinhibitory facilitation (rebound). When the noxious electrical shocks were given over prolonged periods (140 s) the suppression of the flexor reflex was seen to outlast the central stimulation by more than 100 s. Intravenous injection of naloxone or methysergide failed to reverse the effects of the brain stimuli. It is suggested that the hypothalamic induced inhibition of withdrawal reflexes is functionally meaningful in view of the incompatibility between these reflexes and the locomotor behavior which is part of the behavioral responses (i.e. fight or flight) controlled by this area.

Analgesia↗

Cytometrical and immunocytochemical investigation of brain nuclei in dementia.

Morphometrical investigation of brain nuclei in dementia of the Alzheimertyme and in other types of dementia has been done for the last 10 years. The N. Basalis of Meynert (Acetylcholine pathway) has been screened rather extensively by several groups. The L. Coeruleus (Nor-adrenergic pathway) also has been fairly well documented. The N. Raphe Dorsalis however-an important relay nucleus in the serotonergic pathway-was only studied cytometrically by a few groups. Other nuclei were not investigated systematically f.e. N. Accumbens; this nucleus might play an important role however in memory disturbances via Gabaergic influence on excitatory amino acids. This quantitative study focuses on those less well studied brain areas. A cytometrical analysis (cell counts-cell sizing) was performed on serial sections in clinically well-documented cases of different types of dementia: Alzheimer, Pick, Huntington, Jakob-Creutzfeldt. Results were compared with controls and for the N. Accumbens also with the values obtained in the brain of catatonic schizophrenics. The cell sizing and counting was done on cresylviolet sections, on modified Bielschowsky-stained sections and on Peroxidase-Anti-Peroxidase (P.A.P.) treated sections with a polycloncal antibody against Alzheimer Paired Helical Filaments (PHF). Our results show that the nerve cell degeneration in those nuclei is quite different in the diverse types of dementia, pointing to a disease specific physiopathology.

Aged↗

Diffuse fasciitis after bone marrow transplantation.

This report describes a patient in whom the clinical, laboratory, and histologic features of diffuse fasciitis with eosinophilia developed several months after allogeneic bone marrow transplantation for acute lymphoblastic leukemia. Numerous reports detail the association between diffuse fasciitis and hematologic diseases; a patient in whom diffuse fasciitis developed in the setting of chronic graft-versus-host disease following bone marrow transplantation for acute leukemia is discussed. Treatment of the chronic graft-versus-host disease improved the symptoms of the diffuse fasciitis.

Adult↗

The arcuate nucleus: a site for gamma-aminobutyric acid regulation of prolactin secretion.

The effects on prolactin (Prl) secretion following microinfusion of muscimol or N-methyl-aspartate (NMA) into the medial basal hypothalamus (MBH) of male rats was determined. A highly significant increase in Prl occurred following microinfusion of muscimol (500 pmol) into the arcuate nucleus. Microinfusion of muscimol into nearby sites, such as the ventromedial nucleus and dorsal medial nucleus, was not effective in altering Prl secretion. Similarly, microinfusions of artificial cerebrospinal fluid were not effective. NMA (50 pmol), a dose found to affect hormone secretion in other CNS areas, did not alter Prl secretion when infused into the MBH. The present study was able to discriminate between CNS areas by using small volumes (250 nl) and small quantities of the amino acid agonists. This data indicates that GABAergic systems in the arcuate nucleus control Prl release from the pituitary, and that one possible mechanism is via the tuberoinfundibular dopamine system.

Animals↗

Kallikrein localization in rat brain by immunohistochemistry.

Using an antibody-peroxidase bridge technique with either polyclonal antibodies or a specific monoclonal antibody, immunoreactive kallikrein was localized in all three lobes of the pituitary, in ependymal cells lining the third ventricle, and in cell bodies of the following hypothalamic neuronal nuclei: supraoptic, arcuate, paraventricular and ventromedial.

Animals↗

Locked-in syndrome with bilateral ptosis: combination of bilateral horizontal pontine gaze paralysis and nuclear oculomotor nerve paralysis.

A patient with a classical locked-in syndrome is described, in whom bilateral ptosis was observed on the 2nd day. On the 4th day, ophthalmoplegia was complete with the exception of a voluntary downward movement of the right eye. The syndrome can be explained by the association of bilateral horizontal pontine gaze palsy and a unilateral nuclear oculomotor nerve palsy, and approximates the "total locked-in syndrome".

Adult↗