6 results on '"Surcheva, Slavina"'
Search Results
2. Dihydropyrimidine dehydrogenase level and the redox status in patients with colorectal cancer are prognostic for adverse effects of fluoropyrimidines.
- Author
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Hristova-Avakumova, Nadya G., Minchev, Velko T., Kamenova, Kalina V., Todorov, Lozan T., Angelov, Marin P., Atanasova, Liliya A., Surcheva, Slavina K., and Nikolov, Rumen P.
- Subjects
DIHYDROPYRIMIDINE dehydrogenase ,COLORECTAL cancer ,LEUKAPHERESIS ,LIPID peroxidation (Biology) ,CANCER patients ,LEUKOCYTE count ,GRANULOCYTES ,LEUCOCYTES - Abstract
Drug resistance and toxicity are the most widespread limitations in the pursuit of sufficient antitumor effectiveness and successful control of oncological diseases, including colorectal cancer (CRC). Herein the objective was to investigate some hematological side effects of the chemotherapeutic regimen FOLFOX-4, their relation to dihydropyrimidine dehydrogenase (DPD) levels and the associated alterations in CRC patients' plasma free-radical scavenging properties and extent of oxidative molecular damage. Thirty-eight patients with histologically confirmed CRC diagnoses, assigned to chemotherapy with the FOLFOX-4 regimen, were recruited. The diagnostic methods included a complete physical examination, blood routine test and general biochemistry. The DPD levels were assayed. The patients' plasma free-radical scavenging properties and extent of molecular oxidative damage were determined by spectrophotometry and enhanced chemiluminescence. The clinico-pathological and demographics characteristics of the patients were in agreement with the reports from retrospective cohort studies. The FOLFOX-4 regimen induced a decrease in plasma free-radical scavenging properties and increased extent of lipid peroxidation. White blood cells, granulocytes and lymphocytes decreased significantly after the first cycle of the therapy. The patients' DPD level decreased statistically significantly in the case of severe reduction (more than 25%) of white blood cells and granulocyte counts. The obtained data are in agreement with already known facts concerning the side effects of the FOLFOX-4 regimen and associated changes in redox homeostasis. Genetic predisposition to effectively metabolize and tolerate the applied therapy, i.e. DPD levels, could modulate some aspects of the observed changes in the aforementioned parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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- View/download PDF
3. Analgesic activity of some aroylhydrazone-based molecular hybrids with antiseizure activity: in vivo and in silico evaluations.
- Author
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Marchev, Stanislav, Andreeva-Gateva, Pavlina, Tzoneva, Roumiana, Surcheva, Slavina, Tzonev, Alex, Kamenova, Kalina, Angelova, Violina T., Tchekalarova, Jana, and Vlaskovska, Mila
- Subjects
ANALGESICS ,COUMARIN derivatives ,NICOTINAMIDE adenine dinucleotide phosphate ,SEIZURES (Medicine) ,COUMARINS - Abstract
We have recently identified several aroylhydrazone-based molecular hybrids with antiseizure activity. We aimed to investigate the analgesic activity of these molecules further. Male ICR mice were injected intraperitoneally with the tested substances or with the vehicle only (controls). We performed hot plate tests, formalin test and maximal electroshock (MES) test and further studied the cytokine proteome in the brain. In silico analysis was performed for prediction of the physicochemical parameters and activity. The furan-substituted aroylhydrazone-based 2H-chromene hybrid showed a significant increase of the latent time as compared with the baseline values (p <.05). Both the chlorine-substituted and the methyl-substituted aroylhydrazone-based coumarin derivatives significantly decreased the first phase of the formalin test (p <.05). We also found suppression of all the cytokines which were overexpressed in the model of acute seizures (MES test) and in the formalin paw test. The in silico model predicted hydroxymethylglutaryl coenzyme A synthetase 2 (HMGCS2) enhancer activity. Further testing is needed to confirm the mechanism of the potentially beneficial effects of the tested substances and to evaluate the toxicity and efficacy of the proposed molecules. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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4. Action of adrenal and gonadal steroid hormones on kainic acid-evoked seizures in a rat model of epileptogenesis.
- Author
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Surcheva, Slavina, Marchev, Stanislav, Tashev, Roman, Belcheva, Stilyana, and Vlaskovska, Mila
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SEX hormones ,KAINIC acid ,ALZHEIMER'S disease ,LABORATORY rats ,MENTAL depression - Abstract
Epilepsy is one of most reported neurological disorders after migraine, stroke and Alzheimer's disease. Empiric clinical data reveal that seizures and epilepsy more likely affect men than women. The aim of present study was to investigate the effect of steroid adrenal and gonadal hormones on the intensity, dynamics and latency of kainic acid-evoked seizure and lethality in a rat model of epileptogenesis. After surgical adrenalectomy/gonadectomy, male rats wereat randomassorted in groups and treated from postoperative day 1 to day 5 with corticosterone (30 mg/kg), estradiol (0.03 mg/kg), progesterone (75 mg/kg), dihydroprogesterone (75 mg/kg) and dihydrotestosterone (0.75 mg/kg). Spontaneous recurrent seizures generated by kainic acid were assessed. The treatment with corticosterone eliminated the aggravation of kainic acid-evoked seizures produced by adrenalectomy/gonadectomy. The application of corticosterone decreased the seizure intensity by 31% and prevented seizure-associated animal death. The effect of estradiol treatment was quite opposite. Estradiol treatment exacerbated the somatic and behavioural aspects of kainic acid-evoked epilepsy-like syndrome. The hormone increased the intensity of kainic acid-evoked seizures by 31%, decreased the latency of clonic weak seizures by 49% and enhanced the associated lethality by 133%. The treatment with progesterone or dihydroprogesterone produced minor alterations in intensity and latency of kainic acid-evoked seizures in the operated male rats. The application of dihydrotestosterone significantly aggravated the kainic acid-evoked seizures. In summary, hormonal unbalance could play an important role for seizure susceptibility in epileptogenesis. Corticosterone has better anti-seizure activity than progesterone and testosterone has significant pro-convulsive activity. [ABSTRACT FROM PUBLISHER]
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- 2017
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5. In vitro and in silico evaluation of chromene based aroyl hydrazones as anticonvulsant agents.
- Author
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Angelova, Violina, Voynikov, Yulian, Andreeva-Gateva, Pavlina, Surcheva, Slavina, Vassilev, Nikolay, Pencheva, Tania, and Tchekalarova, Jana
- Abstract
Series of aroyl hydrazones of 2 H-chromene and coumarin carbaldehydes were synthesized and evaluated for their anticonvulsant activity and neurotoxicity. Further docking study on gamma-aminobutyric acid receptor was performed to elucidate their mechanisms of action. The highest protection was demonstrated by 2-furyl substituted 2 H-chromene 8b in the maximal electroshock test (ED = 12.51 mg kg, PI MES > 23.98) and the subcutaneous pentylenetetrazole tests (ED = 127.10 mg kg). Furyl-substituted derivative 4b (ED = 68.66 mg kg) was the most active in the maximal electroshock test while methoxyphenyl-substituted derivate 4c was the most active in the 6-Hz test (ED = 94.34 mg kg). None of the compounds displayed neurotoxicity in the rota-rod test. In silico assessment of their blood-brain barrier permeability indicated them as central nervous system active agents. The results suggest that coumarin/2 H-chromene aroyl hydrazones scaffold deserve further evaluation in models of epilepsy and derivatization. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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6. Preclinic and clinic effectiveness of gabapentin and pregabalin for treatment of neuropathic pain in rats and diabetic patients.
- Author
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Surcheva, Slavina, Todorova, Lubina, Maslarov, Dimitar, and Vlaskovska, Mila
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PREGABALIN ,GABAPENTIN ,NEUROPATHY ,PEOPLE with diabetes ,CENTRAL nervous system ,THERAPEUTICS - Abstract
Pregabalin and gabapentin are amino-acid derivatives of gamma-aminobutyric acid. They have a high affinity to the α2δ protein in the central nervous system and both have been shown to be effective for neuropathic pain disorder. The aim of this study was to investigate the efficacy of gabapentin and pregabalin in animal models of neuropathic pain, and to correlate with clinical outcomes in patients with diabetic neuropathy. Gabapentin (60 mg/kg) and pregabalin (30 mg/kg) attenuate mechanical, tactile and heat hypersensitivity in rats with chronic constriction injury of the sciatic nerve and streptozotocin (STZ)-induced diabetes. There is no evidence that one of the drugs is superior to another at the different rat models and tests. In the incisional pain model, there was partial efficacy of gabapentin. Our clinical data suggest that relative to the baseline pain score, the treatment with pregabalin at doses of 300 mg/day or gabapentin at doses of 900 mg/day would be effective and well tolerated in patients diagnosed with moderate diabetic polyneuropathy. The study suggested that pregabalin may provide better analgesic outcomes than gabapentin on the sixth month of treatment. In conclusion, the comparative effects of gabapentinoids in animal models of neuropathic pain and neuropathic patients are suggestive of similar pathophysiological mechanisms being involved, but successful outcome is determined by a patient's individuality and the drug nature as well as the drug tolerability. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
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