Biomedical subjects

H Dudek

Publications and source records attributed to H Dudek.

At least 19 recordsLinked to original sources

PubMed2001

[Long-term results of surgical treatment of lumbar disk herniation in adults].

The authors present long-term results (10.2 years post-op) of surgical treatment of lumbar disc herniation in 1003 patients operated at the Department of Neurosurgery by the University of Medical Sciences in Białystok. The operated group comprised 33.1% women (mean age--55.6 years) and 68.7% men (mean age 57.3 years). Ten years post-op 15.9% women and 5.8% men kept the recommended diet, 14% women and 7.0% men continued muscle strengthening exercise. Ten years post-op excellent and good results were noted in respectively 42.4% and 46.5% women and 45.4% and 46.6% men.

Adult↗

PubMed2001

[Giant intradural disk herniation].

The authors present a rare case of the total intradural sequester from a prolapsed lumbar disc at the L4 level. This kind of hernations comprise 0.3% of all disc hernations. Surgical treatment resulted in a good outcome.

Adult↗

PubMed2001

[Activity of glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R) and superoxide dismutase in the brain tumors].

The aim of the study was to estimate the activity of glutathione peroxydase, glutathione reductase and superoxide dysmutase in the brain tumours. The activity of GSH-Px was evaluated with the use of spectrophotometry, GSSG-R was evaluated based on the Mize and Langdon method, and SOD-1 with Sykes et al. method. The 55 specimens (45 specimens of neoplasm and 10 specimens of healthy brain tissue) were studied. The statistical analysis revealed significant increase of enzymes within the brain tumours in comparison to the healthy brain tissue.

Brain Neoplasms↗

PubMed2001

[Concentration of glutathione (GSH), ascorbic acid (Vit. C), and thiobarbiturate acid reacting components (MDA) in brain neoplasms].

The aim of the study was to evaluate the concentration of glutathione (GSH), ascorbic acid (Vit C), and thiobarbiturate acid reacting components (MDA) in brain neoplasms in specimens from normal brain tissue. The group of 72 individuals treated surgically for brain neoplasm in Department of Neurosurgery Medical Academy of Białystok (Poland) in the period from 1996 to 1999 was included into the study. The GSH concentration was estimated with GSH-400 method, ascorbic acid by the use of Kyaw method, and MDA by Salaris and Babs method. The statistical analysis revealed diminished concentration of GSH and Vit. C (p < 0.001), and analogous increase of MDA concentration (p < 0.001) in the investigated specimens compared to the mentioned above substances concentration in the specimens obtained from normal brain tissue.

Adult↗

PubMed2000

[Lateral lumbar disk herniation].

The authors present the clinical evaluation of 41 patients with extreme lateral disc herniation in the lumbar spine. This group of patients represented 3.1% of all patients operated to to discopathy of the lumbar spine at the Department of Neurosurgery of the Medical Academy of Białystock in the years 1988-1997. Males constituted 95.1% of the study series, with an age range 41-60 years. In 92.7% of the patients extreme lateral herniation was diagnosed either at L4-L5 level or L5-S1 level. In 78.1% of the cases different types of motoric disturbances were observed, while in 65.8% radicular type disorders in superficial sensibility were noted.

Adult↗

PubMed2000

[Early results of surgical treatment of herniated nucleus pulposus in the lumbar spine in adults patients].

Between 1978 and 1997, 2250 patients underwent surgery due to nucleus pulposus herniation in the lumbar spine at the Department of Neurosurgery of the Medical Academy in Białystok. Surgery was performed on 718 women (31.9% of the cases) and 1532 men (68.1% of the cases) age ranging from 19 to 71 years. In 90.1% of cases herniation was found at levels L4-L5 and L5-S1. In most cases the herniated disc was removed following a fenestration (58.7% of the cases) or following hemilaminectomy of the vertebral arch (28.5% of the cases). Basing on a questionnaire sent out 12 months post-surgery 78.3% of the female patients and 68.3% of the male patients evaluated the results of the above treatment as very good. Within the 12 months observation follow-up period, 9.9% of the analyzed group underwent repeated surgery.

Adult↗

PubMed2000

Neoplasms of the central nervous system of lipoid origin.

In general tumours of lipoid origin are benign. A high proportion of cases are mesenchymal neoplasms localised in subcutaneous tissue. Neurological signs related to compression of neural structures by fat within the vertebral canal were first presented in 1975. The lipogenic neoplasms represent 1-4% of spinal tumours, and generally are associated with congenital disorders of the spine. These fatty swellings are usually benign, but penetrating deeply into the spine, and connecting with spinal cord, cauda equina or filium terminale, they produce deficits. The deficits may be present at birth but they may also occur in the middle age. These events are classified as epidural lipomatosis (mostly observed in patients on chronic steroid treatment) or as lipoma, common in spinal disraphism. Intracranial tumours of lipoid origin are very rare (0.06-0.5% of brain tumours), and are probably congenital. They occur anywhere within the cranium, however a high proportion of cases tend to be located around the midline, and approximately 50% of tumours are found in the corpus callosum. Usually they are asymptomatic, and when the symptoms occur, they are frequently a result of general clinical condition. The authors present three cases of lipomatous tumours; one intracranial and two of spinal location.

Adult↗

PubMed1999

Late posttraumatic epilepsy in patients with an alcoholic problem treated surgically for posttraumatic chronic subdural hematomas.

The frequency and time of late posttraumatic epilepsy in 34 patients (6 women and 28 men) was evaluated on the basis of a three-year observation and performed examinations (CT of the head and EEG). These patients were treated surgically in the years 1989-1994 in the Department of Neurosurgery of the Medical Academy of Białystok due to chronic posttraumatic subdural hematoma. On the basis of environmental and family interviews it was concluded that 41.1% of the patients operated systematically abuses alcohol. Within 14-30 minutes following the surgery, seizures of late posttraumatic epilepsy took place in 20.6% of patients. They took place over eight times more frequently in the case of patients with alcohol problems that in the ones without such problems.

Adult↗

PubMed1999

[Anamnestic and anthropometric assessment of patients with herniated lumbar intervertebral disc].

The paper presents results of anamnestic and anthropometric assessment of patients with herniated lumbar intervertebral disc operated in the Department in the years 1978-1987 (983 patients) and in the decade 1988-1997 (1308 patients). Recent decade brought 33.1% increase in disectomies. Typically, discopathy patient is tall individual, with relatively high BMI and aged between 19 and 48 years. The number of female patients increased by 8.2% in recent decade and traumatic origin of the disc herniation was noted in 8.8% more than previously. Special attention should be paid to the twofold increase of female smokers among patients operated due to discopathy.

Adult↗

PubMed1998

[Long-term results of surgical treatment of lumbar discopathy in children and adolescents].

Long-term results of surgical treatment of lumbar discopathy in 29 patients with 5 years follow-up (14 girls, 15 boys) operated at the age of 13-18 years in Neurosurgery Department, Medical University in Białystok between 1970 and 1993. Ten years follow-up was available in 26 patients (14 girls, 12 boys) operated between 1970 and 1988. Over period of 10 years 64.3% girls and 16.7% boys preserved recommended diet, 92.8% and 8.3% boys continued muscle strengthening exercises. Cigarette smoking abandoned 100% girls and none of the boys. Ten years after surgical treatment for lumbar discopathy excellent results were found in 85.7% females and 50% males.

Adolescent↗

PubMed1998

[Immediate and short-term results of surgical treatment for lumbar disc protrusion in children and adolescents].

Twenty-nine patients aged 13-18 (14 girls and 15 boys) were treated surgically for lumbar intervertebral disc herniation at Department of Neurosurgery, Medical University in Białystok between 1970 and 1993. Clinical and radiological assessment of these patients and results of surgical treatment are presented. The condition was of traumatic origin in 30% of the cases. Neurological deficit has been found in 16.6% of children below 15 years of age and in 50% of patients up to 18 years of age. The results were rated good in 100% of the children up to 15 and in 87% adolescents below 18 years of age at one month follow-up and, respectively, 100% and 78.3% at one year follow-up.

Adolescent↗

PubMed1997

Akt phosphorylation of BAD couples survival signals to the cell-intrinsic death machinery.

Growth factors can promote cell survival by activating the phosphatidylinositide-3'-OH kinase and its downstream target, the serine-threonine kinase Akt. However, the mechanism by which Akt functions to promote survival is not understood. We show that growth factor activation of the PI3'K/Akt signaling pathway culminates in the phosphorylation of the BCL-2 family member BAD, thereby suppressing apoptosis and promoting cell survival. Akt phosphorylates BAD in vitro and in vivo, and blocks the BAD-induced death of primary neurons in a site-specific manner. These findings define a mechanism by which growth factors directly inactivate a critical component of the cell-intrinsic death machinery.

3T3 Cells↗

PubMed1997

Regulation of neuronal survival by the serine-threonine protein kinase Akt.

A signaling pathway was delineated by which insulin-like growth factor 1 (IGF-1) promotes the survival of cerebellar neurons. IGF-1 activation of phosphoinositide 3-kinase (PI3-K) triggered the activation of two protein kinases, the serine-threonine kinase Akt and the p70 ribosomal protein S6 kinase (p70(S6K)). Experiments with pharmacological inhibitors, as well as expression of wild-type and dominant-inhibitory forms of Akt, demonstrated that Akt but not p70(S6K) mediates PI3-K-dependent survival. These findings suggest that in the developing nervous system, Akt is a critical mediator of growth factor-induced neuronal survival.

Androstadienes↗

PubMed1996

Murine myeloid leukemic cells with disrupted myb loci show splicing anomalies that account for heterogeneous sizes in myb proteins.

The ABPL tumor cell lines represent a group of myeloid cell lines which contain an altered myb locus due to viral insertional mutagenesis within the third exon of c-myb. Immunoprecipitation analysis of the proteins produced in three ABPL lines revealed an interesting anomaly. Despite the invariant position of the virus integration event, the three ABPL tumor cell lines we examined (ABPL-1, ABPL-2 and ABPL-4) produced three different sized proteins. In this report, we examined the molecular basis for this protein size heterogeneity. Molecular cloning and sequence analysis of the cDNAs derived from the myb transcripts show that ABPL-1 tumor produces a tripartate mRNA containing sequences derived from the viral gag and env genes fused to the myb coding region. This results in the synthesis of a 74 kd protein. In the ABPL-2 tumor line, a gag-myb fusion protein is produced which is of 68 kd. In ABPL-4 cell line a gag-myb fusion protein is produced which contains an internal deletion of coding sequences derived from exons 13 and 14. This deletion results in the synthesis of a 59 kd protein in ABPL-4 tumor cell line. These observations were further confirmed by RNase protection assays which demonstrate the presence of aberrantly spliced mRNAs in ABPL-1 and ABPL-4 tumor cells but not in cells containing an undisrupted c-myb locus. In vitro translation and immuno-precipitation analysis of the cRNAs derived from the ABPL-1, ABPL-2 and ABPL-4 cDNAs show the synthesis of protein products that were identical to Myb proteins produced by these tumors in vivo. These results suggest that integration of Mo-MuLV within the c-myb locus not only results in deletions of the 5' end of the transcript but splicing aberrations within the encoded mRNA, which results in the synthesis of a heterogeneous array of proteins, not seen in normal hematopoietic cells.

Amino Acid Sequence↗

PubMed1996

Calcium influx via the NMDA receptor induces immediate early gene transcription by a MAP kinase/ERK-dependent mechanism.

The regulation of gene expression by neurotransmitters is likely to play a key role in neuroplasticity both during development and in the adult animal. Therefore, it is important to determine the mechanisms of neuronal gene regulation to understand fully the mechanisms of learning, memory, and other long-term adaptive changes in neurons. The neurotransmitter glutamate stimulates rapid and transient induction of many genes, including the c-fos proto-oncogene. The c-fos promoter contains several critical regulatory elements, including the serum response element (SRE), that mediate glutamate-induced transcription in neurons; however, the mechanism by which the SRE functions in neurons has not been defined. In this study, we sought to identify transcription factors that mediate glutamate induction of transcription through the SRE in cortical neurons and to elucidate the mechanism(s) of transcriptional activation by these factors. To facilitate this analysis, we developed an improved calcium phosphate coprecipitation procedure to transiently introduce DNA into primary neurons, both efficiently and consistently. Using this protocol, we demonstrate that the transcription factors serum response factor (SRF) and Elk-1 can mediate glutamate induction of transcription through the SRE in cortical neurons. There are at least two distinct pathways by which glutamate signals through the SRE: an SRF-dependent pathway that can operate in the absence of Elk and an Elk-dependent pathway. Activation of the Elk-dependent pathway of transcription seems to require phosphorylation of Elk-1 by extracellular signal-regulated kinases (ERKs), providing evidence for a physiological function of ERKs in glutamate signaling in neurons. Taken together, these findings suggest that SRF, Elk, and ERKs may have important roles in neuroplasticity.

Animals↗

PubMed1996

The cdk5/p35 kinase is essential for neurite outgrowth during neuronal differentiation.

Cyclin-dependent kinase 5(cdk5) is highly homologous to other members of the cdk family that are known to function in proliferating cells. Despite the structural similarity, cdk5-associated histone H1 kinase activity is only detectable in postmitotic neurons of the central nervous system (CNS). p35 is a neuronal-specific cdk5 regulator that activates cdk5 kinase activity upon association. The cdk5/p35 kinase activity increases during the progression of CNS neurogenesis, suggesting a function of cdk5 in neuronal differentiation. Here we show that both cdk5 and p35 proteins are present in the growth cones of developing neurons. The staining pattern of cdk5 in the growth cones is similar to that of actin filaments but not microtubules. To address the functional significance of the cdk5/p35 kinase in neurogenesis, we ectopically expressed wild-type or mutant kinases in cortical cultures. Expression of dominant-negative mutants of cdk5 (cdk5N144 and cdk5T33) inhibited neurite outgrowth, which was rescued by coexpression of the wild-type proteins. A similar extent of neurite outgrowth inhibition was obtained by transfection of an antisense p35 construct, which in turn was only rescued by p35 but not cdk5 coexpression. In contrast, longer neurites were elaborated in neurons that coexpressed exogenous cdk5 and p35. These observations suggest that the cdk5/p35 kinase plays a critical role in neurite outgrowth during neuronal differentiation.

Animals↗

PubMed1995

Serine 133-phosphorylated CREB induces transcription via a cooperative mechanism that may confer specificity to neurotrophin signals.

A mechanism has been characterized by which the transcription factor CREB regulates neurotrophin-induced gene expression. Whereas CREB can mediate calcium- or cyclic AMP-induced c-fos transcription independently of other promoter-bound transcription factors, CREB mediates NGF induction of c-fos transcription via a novel mechanism that appears to require a cooperative interaction with another transcription factor, the serum response factor. A similar transcriptional mechanism may explain how neurotrophins and growth factors induce distinct subsets of delayed response genes. Neurotrophins induce the phosphorylation of CREB at a key regulatory site, Serine 133, with prolonged kinetics that are distinct from the transient kinetics of CREB phosphorylation elicited by growth factors. These results indicate that CREB is a versatile transcription factor that activates transcription via distinct mechanisms in a stimulus-specific manner. In addition, by selectively activating delayed response genes, CREB may confer specificity to neurotrophin signals that promote the survival and differentiation of neurons.

Animals↗

PubMed1995

N-methyl-D-aspartate receptors are critical for mediating the effects of glutamate on intracellular calcium concentration and immediate early gene expression in cultured hippocampal neurons.

The mechanisms by which activation of excitatory amino acid receptors is coupled to the regulation of gene transcription were studied using cultured hippocampal neurons from neonatal rats. Voltage recording, calcium imaging, specific RNA analysis and immunocytochemistry were carried out on sister cultures. This allowed analysis of the expression of functional glutamate receptor subtypes, examination of their role in controlling intracellular free calcium ([Ca2+]i), and determination of their relative contributions to the transcriptional regulation of six immediate early genes c-fos, fosB, c-jun, junB, zif/268 (also termed Egr-1; NGFI-A; Krox-24) and nur/77 (also termed NGFI-B). Expression of all six immediate early genes was induced in hippocampal neurons by glutamate treatment. Nuclear run-on assays demonstrated that this induction occurred at the transcriptional level. Activation of the N-methyl-D-aspartate subtype of glutamate receptor was necessary and sufficient for the transcriptional response. Non-N-methyl-D-aspartate receptors, while present in cultured hippocampal neurons, contributed relatively little to the regulation of transcription. Calcium imaging showed that glutamate-induced changes in [Ca2+]i were almost entirely mediated by N-methyl-D-aspartate receptors, rather than by L-type voltage-sensitive calcium channels. Previous studies have shown that stimulation with selective agonists of either N-methyl-D-aspartate receptors, non-N-methyl-D-aspartate receptors, or L-type calcium channels can lead to an increase in [Ca2+]i and c-fos expression. Here we demonstrate that in our hippocampal culture system glutamate controls [Ca2+]i and induces immediate early gene transcription primarily by activating N-methyl-D-aspartate receptors.

2-Amino-5-phosphonovalerate↗