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Biomedical subjects

P Olejniczak

Publications and source records attributed to P Olejniczak.

At least 19 recordsLinked to original sources
PubMed2005

Vagus nerve stimulation for epilepsy: randomized comparison of three stimulation paradigms.

Vagus nerve stimulation (VNS) is an effective adjunctive treatment for intractable epilepsy. However, the optimal range of device duty-cycles [on/(on + off times)] is poorly understood. The authors performed a multicenter, randomized trial of three unique modes of VNS, which varied primarily by duty-cycle. The results indicate that the three duty-cycles were equally effective. The data support the use of standard duty-cycles as initial therapy.

Cough↗
PubMed2005

EMG vagus nerve stimulator artifact.

EMG artifact produced by a VNS stimulator is described. A patient with a VNS stimulator underwent an EMG study for suspected ALS. Artifacts that appeared similar to positive sharp waves or fibrillations were noted that could produce a false clinical diagnosis. These VNS-EMG artifacts matched well with the VNS generator's set parameters. We conclude that EMG findings must be interpreted with caution in patients with VNS implants and also that EMG may have a possible monitoring value for VNS activity.

Action Potentials↗
PubMed2005

Mental health symptoms in partial epilepsy.

We evaluated the potential clinical value of the Symptom Checklist-90-Revised (SCL-90-R) as a multidimensional self-report measure to identify the expected higher rates of clinically significant mental health symptoms in adults with partial/complex partial epilepsy (PE), as compared to a representative sample of adult non-patients. As expected, adults with PE had significantly higher rates of elevated SCL-90-R scale scores than did adult non-patients. The SCL-90-R may serve as both a screening measure to identify patients who could benefit from further mental health services as well as a measure of clinical response to epilepsy- and mental health-related interventions.

Adolescent↗
PubMed2004

Expression of two alternative transcription forms of platelet-derived growth factor-A chain in the normal human kidney and in glomerulonephritis.

PURPOSE: Up to now, a role of platelet-derived growth factor (PDGF)-AA in glomerulonephritis (GN) remains unclear. PDGF-A chain may be produced in two forms, as a result of the alternative splicing. MATERIAL AND METHODS: We examined the expression of this growth factor in the renal tissue of 57 patients with GN and seven normal kidneys (NK). The gene expression of PDGF-A was examined by reverse transcriptase-polymerase chain reaction. Sets of primers allowing distinction between the two forms of transcripts were used. Specificity of the PCR products was confirmed by restriction enzyme analysis and sequencing. The expression of PDGF-AA/AB was also evaluated by immunohistochemistry. RESULTS: Compared to NK, the expression of PDGF-A gene was higher in the renal tissue with GN. This expression was higher in non-proliferative GN (NPGN) than in proliferative forms of GN (PGN) (1.24 +/- 0.34 vs. 0.86 +/- 0.14). In NK, both forms of transcripts (N = 4) or only the short one (N = 3) were found. In 45.5% of patients with NPGN, only the short form could be detected. In contrast, in 68.6% of patients with PGN both or only the longer form of transcripts were found. In NK, a faint staining for PDGF-AA/AB was observed within glomerular capillaries, whereas a statistically significant increase in this protein expression was particularly stated in NPGN. These results suggest that the production of the longer PDGF-A chain variant is associated with glomerular cells' proliferation. However, the higher expression of PDGF-AA/AB protein in NPGN could indicate an essential role of this growth factor in the maintaining the glomerular architecture.

Adolescent↗
PubMed2004

Can von Willebrand factor, platelet-endothelial cell adhesion molecule-1 and thrombomodulin be used as alternative markers of endothelial cell injury in human glomerulonephritis?

PURPOSE: There is growing evidence that endothelial cells (EC) are active participants of an inflammatory process in glomeruli. MATERIAL AND METHODS: We compared the glomerular expression of three EC-coupled molecules, i.e. platelet-endothelial cell adhesion molecule-1 (PECAM-1 or CD31), von Willebrand factor (vWF) and thrombomodulin (TM) in 60 patients with glomerulonephritis (GN) and five normal kidneys (NK). The alkaline phosphatase anti-alkaline phosphatase method was used to examine the expression of these proteins in the biopsy specimens. RESULTS: In NK, the expression of CD31 and vWF comprised the whole glomerular network. In contrast, the expression of TM was much lower and localized mainly to EC at the vascular pole and adjacent areas. In GN, the glomerular staining for CD31 and vWF was significantly reduced. A fall in the expression of both these EC antigens was more pronounced in proliferative forms of GN (PGN) than in non-proliferative GN (NPGN) (CD31: NPGN vs. PGN, p < 0.02; vWF: NPGN vs. PGN, p < 0.05). In addition, a linear relationship between the expression of CD31 and vWF was found in GN (r = 0.8, p < 0.001). Conversely to CD31 and vWF, a marked increase in glomerular reactivity for TM was observed in all the patients with GN (GN: 2.12 +/- 0.32, NK: 0.95 +/- 0.05, p < 0.02). However, the highest expression of TM was found in membranoproliferative GN and lupus GN. CONCLUSIONS: Our results suggest that CD31 and vWF may be used as markers of glomerular EC loss during GN, whereas TM staining seems to reflect EC activation in response to circulating and/or released in situ procoagulant factors.

Adolescent↗
PubMed2000

Epilepsia partialis continua in Creutzfeldt-Jakob disease.

OBJECTIVES: We describe a patient with Creutzfeldt-Jakob disease (CJD) with epilepsia partialis continua (EPC) and complex partial seizures. MATERIAL, METHODS AND RESULTS: The patient presented with semi-rhythmic jerking movements of the right upper extremity. Serial EEG findings showed progressive changes with initial periodic lateralizing epileptiform discharges (PLEDs) on the left hemisphere which evolved into more generalized periodic sharp wave complexes (PSWCs) at later stage. Video-EEG monitoring recorded complex partial seizures originating from the left hemisphere in addition to EPC. CONCLUSIONS: A diagnosis of CJD should be considered when a rapidly progressive dementia is accompanied by abnormal movements. EPC, although rare, may present as an initial manifestation of CJD.

Adult↗
PubMed1994

Experimental seizures in the frog (Rana pipiens).

We investigated the effects of chemical convulsants in the leopard frog. Systemic kainic acid (5-20 mg/kg) caused limbic-like seizures, with staring, catatonia, fasciculations, and severe motor seizures, which were almost always lethal. Intracerebral electroencephalographic (EEG) recordings showed spike or spike-and-wave patterns at 6-8 Hz that decreased in frequency and increased in amplitude, maximal at an electrode in the midline olfactory/telencephalic (OLF-M) region. With time, an interictal pattern of 100-200 microV periodic spikes developed, followed by diffuse suppression of all brain activity. Seizures induced by pentylenetetrazole (150-450 mg/kg) and bicuculline (5-10 mg/kg) were characterized by the abrupt onset of motor activity, which continued intermittently for several hours, followed by recovery. EEG recordings in animals treated with pentylenetetrazole showed rhythmic spike-and-wave bursts at 1.5-3 Hz that were maximal at OLF-M. Recordings from frogs treated with bicuculline showed repetitive 3-6 Hz spike-and-wave discharges maximal at OLF-M that were nearly constant in amplitude and at times became continuous. Strychnine (1-5 mg/kg) caused reversible seizures characterized by tonic extensions of the extremities, that seemed to originate in the spinal cord. Frogs with recurrent seizures from systemic cis-diamminedichloroplatinum II showed 4-8 Hz rhythmic spike-and-wave activity that gradually slowed in frequency and increased in amplitude. Thus, the frog's reactivity to convulsive agents is similar to that of mammals.

Animals↗
PubMed1990

[Histology of the central nervous system in rats after intensive chronic ethanol intoxication].

The influence of intensive chronic intoxication with ethanol on adult Wistar rats was investigated. The animals received through a stomach pump 5 ml of 40% ethyl alcohol solution daily for three months. Structural lesions of the CNS observed in the light microscope consisted of acute and chronic edematous changes with infiltration of mononuclear cells and presence of lymphocytic-microglial nodules and myelin discoloration. Sclerotization of nerve cells with reactive gliosis was also noted in the CA1 sector of ventral hippocampus. The pattern of changes is comparable with the most frequently observed pathological abnormalities observed in the CNS of humans after alcohol abuse.

Alcoholism↗
PubMed1990

[Neurologic manifestations of chronic alcoholism].

The authors have analyzed histories of 146 alcoholics admitted to the Clinic of Neurology. Results of this analysis and review of the literature became background for presentation of contemporary views on the clinic and neuropathology of chronic alcoholism.

Adult↗
PubMed1988

Astrocytes are important for sprouting in the septohippocampal circuit.

Damage to the fimbria-fornix, and separately to the perforant path, leads to distinct and dramatic time-dependent increases in glial fibrillary acidic protein immunoreactivity (GFAP-IR) in specific areas of the hippocampal formation. Specifically, fimbria-fornix lesions resulted in an increase in the GFAP-IR in the pyramidal and oriens area of the CA3 as well as the inner molecular layer of the dentate gyrus. In addition, in the septum ipsilateral to the lesion, there was a rapid and robust increase in GFAP-IR in the dorsal lateral quadrant of the septum, but not in the medial region. Only after 30 days did the GFAP-IR reach the medial septum. Following perforant path lesions, there was a selective increase in GFAP-IR in the outer molecular layer of the dentate gyrus. Most of these changes were transient and had disappeared by 30 days postlesion. We speculate that the increase in GFAP-IR in these target areas is a necessary requirement for the sprouting responses that are observed. This hypothesis is supported by the fact that astrocytes secrete NGF in vitro and that NGF activity increases in these target areas following these same lesions. A mechanism for the selective activation of the astrocytes through the initial activation of microglia and secretion of interleukin-1 is postulated.

Animals↗