PubMed Health⌕ Search

Biomedical subjects

L Stepień

Publications and source records attributed to L Stepień.

At least 19 recordsLinked to original sources
PubMed2001

Powdery mildew resistance genes in wheat: verification of STS markers.

Five accessions of Aegilops speltoides and 67 European wheat cultivars (winter and spring) originating from the Czech Republic, Germany, Poland, Russia, Slovakia, United Kingdom, and 4 non-European wheat cultivars from Brazil and the USA were examined with molecular Sequence Tagged Site (STS) markers for resistance genes to powdery mildew: Pm 1, Pm 2, Pm 3 and Pm 13. All markers gave clear, repeatable results, although three of them (Pm 1, Pm 2 and Pm 3) appeared as not specific for resistance genes. Comparison of STS analysis results with Pm genes, postulated as the reaction type after inoculation with differential isolates of Erysiphe graminis f.sp. tritici (Blumeria graminis), revealed a high number of disparities. The marker for Pm 13 was not detected in any examined cultivar but was present in five accessions of Aegilops speltoides.

Journal Article↗
PubMed2001

Molecular markers for leaf rust resistance genes in wheat.

Over 100 genes of resistance to rust fungi: Puccinia recondita f. sp. tritici, (47 Lr - leaf rust genes), P. striiformis (18 Yr - yellow rust genes) and P. graminis f. sp. tritici (41 Sr - stripe rust genes) have been identified in wheat (Triticum aestivum L.) and its wild relatives according to recent papers. Sixteen Lr resistance genes have been mapped using restriction fragments length polymorphism (RFLP) markers on wheat chromosomes. More than ten Lr genes can be identified in breeding materials by sequence tagged site (STS) specific markers. Gene Lrk 10, closely linked to gene Lr 10, has been cloned and its function recognized. Available markers are presented in this review. The STS, cleaved amplified polymorphic sequence (CAPS) and sequence characterized amplified regions (SCAR) markers found in the literature should be verified using Triticum spp. with different genetic background. Simple sequence repeats (SSR) markers for Lr resistance genes are now also available.

Journal Article↗
PubMed1990

Function of dog's auditory cortex in tests involving auditory location cues and directional instrumental response.

Twenty one dogs, distributed into four groups, were trained pre-operatively in differentiation of auditory location or frequency cues. In each group instrumental responses, reinforced by food consisted in placing by the animal its right paw on the side levers. The first differentiation, go-left, go-right task with two location cues, required the animal to place its paw on the lever opposite to the source of the cue. The second differentiation task with the same location cues required placing the paw on the lever located close to the cue. The third task, involving 700 Hz vs. 1,000 Hz tone, required responding to one lever to the presentation of one tone and responding to the opposite lever to the presentation of the other. The last task was a symmetrically reinforced go, no-go differentiation with, again, auditory location cues: the animals were trained to place the paw on a lever to one location cue and to withhold this response to the other location cue. Bilateral ablation of the primary auditory cortex produced a considerable impairment of the performance of the two go-left, go-right tasks involving location cues. The go-left, go-right task employing frequency cues, and the symmetrically reinforced go, no-go task with location cues, were only slightly disturbed by this lesion.

Animals↗
PubMed1981

Late results of operation in temporal lobe epilepsy in adults and children.

In our clinic at the Medical Academy in Warsaw 282 patients with temporal lobe epilepsy were treated surgically. The causes of the illness were trauma in 43.2%, including birth trauma in 19.5%, infections diseases in early life in 19.8%, and microtumours in 6.8%. In 30% the aetiology was unknown. Fifty per cent had fits before 10 years and 75% before 20 years of age. The period of conservative treatment was on average nine years. Serial and stereo-EEG recordings including activation by ketamine, as well as intracarotid sodium amytal tests were performed routinely. The interictal EEG epileptiform abnormalities were found most frequently in both temporal lobes (154 cases). The operation was carried out according to Penfield's technique, with electrocorticography and resection of the temporal lobe extending for 6 to 10 cm in the nondominant hemisphere and for 4 to 5 cm in the dominant hemisphere using suction technique. In 75% microscopical changes in the hippocampus were found, in 20% so-called hamartomas and in 6.8% small gliomas. Two patients died and in 13 patients there was a hemiparesis which was transient in 10. The authors present the analysis of late results of 262 cases with a follow-up from 2 to 22 years after operation. Very good results were obtained in 127 cases (48.5%) - no attacks since leaving the clinic. Good results were observed in 42 patients (16%) - not more than 1-2 attacks a year. Thus, the operation resulted in freedom from attacks, or nearly so, in 169 cases (64.5%). In an additional 47 patients (18%) there was a significant reduction (at least 50%) in seizures without complete freedom from attacks, and in 44 cases (16.8%) no improvement was observed. The analysis of our series suggests that the best results may be obtained in patients with unilateral temporal EEG changes. The existence of an additional focus in parts of the other temporal lobe does not impair the operative results when the dominant epileptic focus has been removed. Among 24 cases with equally pronounced bitemporal EEG abnormalities the stereo-EEG studies allowed detection of the epileptic focus in 13 patients (54%). Detailed analysis of the results, obtained in 51 children below 15 years of age, led to the conclusion that temporal lobe epilepsy should be operated upon even in young children, provided that the epileptic focus can be clearly identified.

Adolescent↗
PubMed1975

Prefrontal cortex and manipulatory go left-go right differentiation to acoustic directional cues in dogs.

In 20 dogs the manipulatory go left – go right differentiation to acoustic directional cues was elaborated. All dogs received total prefrontal, or dorsolateral (total or partial) or medial (total or partial) cortical ablations. All total ablations markedly affected performance of the task, whereas the partial removals produced moderate or no impairment. Thus, both the dorsolateral and medial prefrontal cortex are involved in this type of differentiation.

Animals↗
PubMed1972

The effects of the removal of the somatosensory areas I and II on left leg-right leg differentiation to tactile stimuli in dogs.

Dogs were trained to lift the right forelegs to a rhythmic tactile stimulus applied to the right side of the trunk, and to lift the left forelegs to a tactile stimulus applied to the left side of the trunk. After training was completed various ablations of sensory I area and sensory II area were made. It was found that the task was impaired after unilateral or bilateral SII lesions, but was virtually preserved after SI lesions.

Animals↗
PubMed1972

Effects of prefrontal lesions on left leg-right leg differentiation in dogs.

Twenty five animals trained in the left leg-right leg differentiation were given orbital, proreal or medial precruciate lesions. Pure cortical ablations did not affect the task whereas these deep lesions involving the bundle of fibers inside the prefrontal region caused severe deficit. The medial lesions (superficial and deep) produced disinhibition of the intertrial reactions. The nature of the deficit in the differentiation and the relation between this deficit and the disinhibition is discussed.

Animals↗