Mojca Krzan - Academia.edu (original) (raw)

Papers by Mojca Krzan

Slovenian Medical Journal, 2015

The discovery of cannabinoid receptors and endocannabinoid system has led to the potential therap... more The discovery of cannabinoid receptors and endocannabinoid system has led to the potential therapeutic use of cannabis derivatives. Cannabinoids acting through the CB1 receptors modulate the release of other neurotransmitters in central nervous system, whereas the activation of peripheral CB2 receptors results in decreased inflammatory response and increased apoptosis of some tumor cells populations. The cannabinoids have been authorized for chemotherapy-induced nausea and vomiting; stimulation of appetite; to alleviate neuropathic pain and spasticity in multiple sclerosis, and to reduce pain in cancer patients. Efficacy in other diseases and clinical conditions should be proven in ongoing or future clinical trials. Isolation and identification of different cannabinoids from cannabis and synthesis of novel, more selective, derivatives widens their therapeutic potential. However, there are numerous adverse effects reported, especially when cannabinoids formulations with unknown quant...

Biomolecules, 2020

We used a combination of density functional theory (DFT) calculations and the implicit quantizati... more We used a combination of density functional theory (DFT) calculations and the implicit quantization of the acidic N–H and O–H bonds to assess the effect of deuteration on the binding of agonists (2-methylhistamine and 4-methylhistamine) and antagonists (cimetidine and famotidine) to the histamine H2 receptor. The results show that deuteration significantly increases the affinity for 4-methylhistamine and reduces it for 2-methylhistamine, while leaving it unchanged for both antagonists, which is found in excellent agreement with experiments. The revealed trends are interpreted in the light of the altered strength of the hydrogen bonding upon deuteration, known as the Ubbelohde effect, which affects ligand interactions with both active sites residues and solvent molecules preceding the binding, thus providing strong evidence for the relevance of hydrogen bonding for this process. In addition, computations further underline an important role of the Tyr250 residue for the binding. The o...

Frontiers in Veterinary Science, 2020

An experimental study on the effects of electroporation on pancreatic tissue was performed in pig... more An experimental study on the effects of electroporation on pancreatic tissue was performed in pigs, and the fentanyl transdermal patch (FTP) was used postoperatively as part of multimodal pain management. Ingestion of an FTP, which resulted in fentanyl intoxication, was suspected 5 days after placement in one of the experimental pigs. The pig was first dysphoric, running in the stall, panting and vocalizing until it finally became depressed and it remained lying on the floor. Ingestion of an FTP was not observed but the fentanyl plasma concentration on the day of intoxication was 20.7 ng/ml, while at its peak after FTP administration it was only 0.492 ng/ml. The intoxication was successfully treated with a single intramuscular naloxone injection.

Inflammation Research, Mar 9, 2009

Agents and actions, Mar 1, 1993

In the present work, we identified and characterised histamine H 1-and H2-receptors in highly pur... more In the present work, we identified and characterised histamine H 1-and H2-receptors in highly purified myocardial membranes isolated from female guinea pig ventricles. We determined the binding parameters for the interactions of aH-mepyramine with the histamine H 1-receptor binding site and 3H-tiotidine with the histamine H 2-receptor binding site. Binding of both ligands in our study was saturable, reversible and of high affinity. Scatchard's analysis of the specific 3H-mepyramine binding revealed the existence of high and low affinity binding sites with apparent Ko values of 0.4 nM and 4.5 nM, respectively. The density of binding sites (Bmax) was 100 fmol/mg protein for the high and 466 fmol/mg protein for the low affinity binding site. 3H-tiotidine binds to a single population of binding sites with a KD of 1.0 nM and a Bma x of 27 fmo1/mg protein. These data suggest that both histamine H 1-and H 2-receptors coexist in the guinea pig myocardium with a significantly higher prevalence of the histamine H 1-receptor population.

Veterinary Anaesthesia and Analgesia, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Inflammopharmacology, Sep 1, 1996

Histamine is a normal constituent of mammalian heart. It affects cardiac function mainly through ... more Histamine is a normal constituent of mammalian heart. It affects cardiac function mainly through stimulating histamine H 1-and H2-receptor subtypes. The simultaneous activation of HI-and H2-receptors in the heart results in: a positive inotropic and chronotropic effect, a negative dromotropic effect, increased automaticity and increased coronary blood flow. HI-and H2-receptors have already been cloned from different, but not yet from cardiac, tissue. They are two independent molecular entities differing in the length of their amino acid sequence, pathways of transmembrane and intracelhilar signaling, characteristics of their binding sites and selectivity for the specific agonists and/or antagonists. Our results of radioligand binding studies show the presence in the heart of a high-affinity (KD 0.4 nmol/L and Bmax 100 fmol/mg of protein) and a lowaffinity (KD 4.5 nmol/L, Bm~ 466 fmol/mg of protein) HI-receptor-binding site and only a single population of less-abundant high-affinity H2-receptor binding sites (KD 1.0 nmol/L and Bm,~ 27 fmol/ mg of protein). The role of the histamine in cardiac pathophysiology is well established but the physiological role is unclear. The only proposed physiological role of histamine in the heart is the modulation of noradrenaline release from sympathetic nerve terminals, where H3-receptor subtypes might be involved.

Blood Cells Molecules and Diseases, May 1, 2009

Heparins (unfractionated and low molecular weight (LMWH) heparins) primarily used as anticoagulan... more Heparins (unfractionated and low molecular weight (LMWH) heparins) primarily used as anticoagulants, were found to be effective also in slowing down the development of some types of cancer. On the other hand, the number of microvesicles in the peripheral blood originating from the budding of cell membranes (mostly platelets) is increased in hypercoagulabile states as well as in cancer, indicating a possible common underlying mechanism. It was hypothesized that by mediating an attractive interaction between phospholipid membranes heparin suppresses microvesiculation and thereby acts as an anticoagulant and anti-tumor agent. In this work, the effect of LMWH nadroparin on phospholipid membranes was tested in vitro in a system of giant phospholipid vesicles (GPVs) created by electroformation and observed under the phase contrast microscope. Plasma of different blood donors containing different concentrations of nadroparin was added to the suspension of GPVs to induce adhesion between GPVs. The attractive interaction between membranes was assessed by measuring the average effective angle of contact between the adhered GPVs. It was found in healthy donors, in a donor with gastrointestinal cancer and in a donor with rheumatoid arthritis that adding therapeutic doses of nadroparin to the plasma samples enhanced adhesion of phospholipid membranes in a dose and time-dependent manner while nadroparin alone had no effect within the therapeutic concentration range. The results are in favor of the hypothesis that suppression of microvesiculation underlies both, the anticoagulant and the anti-tumor progression effect of heparin.

Autoimmunity Reviews, 2008

This article was published in an Elsevier journal. The attached copy is furnished to the author f... more This article was published in an Elsevier journal. The attached copy is furnished to the author for non-commercial research and education use, including for instruction at the author's institution, sharing with colleagues and providing to institution administration. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright

Blood Cells Molecules and Diseases, Jul 1, 2008

The Journal of Neuroscience, Mar 1, 2003

Astrocytes are non-neuronal cells in the CNS, which, like neurons, are capable of releasing neuro... more Astrocytes are non-neuronal cells in the CNS, which, like neurons, are capable of releasing neuroactive molecules. However, the mechanism of release is ill defined. In this study, we investigated the mechanism of release of atrial natriuretic peptide (ANP) from cultured cortical astrocytes by confocal microscopy. To study the discharge of this hormone, we transfected astrocytes with a construct to express pro-ANP fused with the emerald green fluorescent protein (ANP.emd). The transfection of cells with ANP.emd resulted in fluorescent puncta in the cytoplasm that represent secretory organelles. If ANP is released by exocytosis, in which the vesicle fuses with the plasma membrane, then the total intensity of the green fluorescing probe should decrease, whereas the vesicle membrane is incorporated into the plasma membrane. To monitor exocytosis, we labeled the membrane with the fluorescent styryldye FM 4-64, a reporter of cumulative exocytosis. The application of ionomycin to elevate cytoplasmic [Ca 2ϩ ] increased the fluorescence intensity of FM 4-64, whereas that of ANP.emd decreased. These effects were not observed in the absence of extracellular Ca 2ϩ , suggesting that ANP is released by regulated Ca 2ϩ-dependent exocytosis from astrocytes.

Inflammopharmacology, 1996

Advances in Planar Lipid Bilayers and Liposomes, 2009

Abstract Astrocytes, which are no longer considered as passive supportive cells of central nervou... more Abstract Astrocytes, which are no longer considered as passive supportive cells of central nervous system, actively participate in brain communication as well as take care for proper microenvironment, because they take up the excess of extracellular potassium ions and neurotransmitters. Neurotransmitter transporters are key elements in terminating synaptic activity of distinct neurotransmitters. They use energy stored in the electrochemical gradient of either sodium ions or protons across neuronal or glial cell membrane for uphill transport of neurotransmitters from extracellular to intracellular site. Sodium‐coupled neurotransmitter transporters belong to two distinct families of transporters of solute carrier proteins (SLC): SLC 1 which represents glutamate transporters and SLC6 to which the other neurotransmitter transporters belong. Apart from neurotransmitter transporters, there is another family in the SLC transporter super family that participates in movement of some monoamines across membranes, a SLC22 family. They act in a sodium‐ and chloride‐independent manner. Because of direct involvement of transporters in the availability of neurotransmitters, they represent a site of action of many present and future drugs. In the present review we would like to address the importance of neurotransmitter transporters on astrocytes in the regulation of synaptic signaling.

Cancer Research, 2009

Antitumor efficacy of intramuscular mIL-12 gene electrotransfer (EGT) in solid subcutaneous sarco... more Antitumor efficacy of intramuscular mIL-12 gene electrotransfer (EGT) in solid subcutaneous sarcoma tumors and their induced lung metastases, alone or combined with local tumor or lung irradiation was studied, and possible interaction between the treatment approaches evaluated. Lung metastases and subcutaneous tumors were induced by intravenous or subcutaneous injection of SA-1 or LPB tumor cells, respectively. Electrotransfer of mIL-12 was performed by intramuscular injection of plasmid DNA followed by local application of electric pulses. Mice bearing subcutaneous tumors were treated by mIL-12 EGT 3-times every second day. Tumor irradiation was performed 1 day after the first EGT. Treatment effectiveness was evaluated by tumor growth delay assay. Mice with induced lung metastases were treated by EGT 24 h before (prophylactic treatment) or at three different time points after the injection of cancer cells. Tumor irradiation was performed 3 days after first EGT. Eight or 14 days pos...

Pharmaceutics, 2021

The plasma concentration profile of bleomycin in the distribution phase of patients younger than ... more The plasma concentration profile of bleomycin in the distribution phase of patients younger than 65 years is needed to determine the suitable time interval for efficient application of electric pulses during electrochemotherapy. Additionally, bleomycin concentrations in the treated tumors for effective tumor response are not known. In this study, the pharmacokinetic profile of bleomycin in the distribution phase in 12 patients younger than 65 years was determined. In 17 patients, the intratumoral bleomycin concentration was determined before the application of electric pulses. In younger patients, the pharmacokinetics of intravenously injected bleomycin demonstrated a faster plasma clearance rate than that in patients older than 65 years. This outcome might indicate that the lowering of the standard bleomycin dose of 15,000 IU/m2 with intravenous bleomycin injection for electrochemotherapy is not recommended in younger patients. Based on the plasma concentration data gathered, a tim...

Proceedings for Annual Meeting of The Japanese Pharmacological Society, 2018

BMC Pharmacology and Toxicology, 2012

Slovenian Medical Journal, 2015

The discovery of cannabinoid receptors and endocannabinoid system has led to the potential therap... more The discovery of cannabinoid receptors and endocannabinoid system has led to the potential therapeutic use of cannabis derivatives. Cannabinoids acting through the CB1 receptors modulate the release of other neurotransmitters in central nervous system, whereas the activation of peripheral CB2 receptors results in decreased inflammatory response and increased apoptosis of some tumor cells populations. The cannabinoids have been authorized for chemotherapy-induced nausea and vomiting; stimulation of appetite; to alleviate neuropathic pain and spasticity in multiple sclerosis, and to reduce pain in cancer patients. Efficacy in other diseases and clinical conditions should be proven in ongoing or future clinical trials. Isolation and identification of different cannabinoids from cannabis and synthesis of novel, more selective, derivatives widens their therapeutic potential. However, there are numerous adverse effects reported, especially when cannabinoids formulations with unknown quant...

Biomolecules, 2020

We used a combination of density functional theory (DFT) calculations and the implicit quantizati... more We used a combination of density functional theory (DFT) calculations and the implicit quantization of the acidic N–H and O–H bonds to assess the effect of deuteration on the binding of agonists (2-methylhistamine and 4-methylhistamine) and antagonists (cimetidine and famotidine) to the histamine H2 receptor. The results show that deuteration significantly increases the affinity for 4-methylhistamine and reduces it for 2-methylhistamine, while leaving it unchanged for both antagonists, which is found in excellent agreement with experiments. The revealed trends are interpreted in the light of the altered strength of the hydrogen bonding upon deuteration, known as the Ubbelohde effect, which affects ligand interactions with both active sites residues and solvent molecules preceding the binding, thus providing strong evidence for the relevance of hydrogen bonding for this process. In addition, computations further underline an important role of the Tyr250 residue for the binding. The o...

Frontiers in Veterinary Science, 2020

An experimental study on the effects of electroporation on pancreatic tissue was performed in pig... more An experimental study on the effects of electroporation on pancreatic tissue was performed in pigs, and the fentanyl transdermal patch (FTP) was used postoperatively as part of multimodal pain management. Ingestion of an FTP, which resulted in fentanyl intoxication, was suspected 5 days after placement in one of the experimental pigs. The pig was first dysphoric, running in the stall, panting and vocalizing until it finally became depressed and it remained lying on the floor. Ingestion of an FTP was not observed but the fentanyl plasma concentration on the day of intoxication was 20.7 ng/ml, while at its peak after FTP administration it was only 0.492 ng/ml. The intoxication was successfully treated with a single intramuscular naloxone injection.

Inflammation Research, Mar 9, 2009

Agents and actions, Mar 1, 1993

In the present work, we identified and characterised histamine H 1-and H2-receptors in highly pur... more In the present work, we identified and characterised histamine H 1-and H2-receptors in highly purified myocardial membranes isolated from female guinea pig ventricles. We determined the binding parameters for the interactions of aH-mepyramine with the histamine H 1-receptor binding site and 3H-tiotidine with the histamine H 2-receptor binding site. Binding of both ligands in our study was saturable, reversible and of high affinity. Scatchard's analysis of the specific 3H-mepyramine binding revealed the existence of high and low affinity binding sites with apparent Ko values of 0.4 nM and 4.5 nM, respectively. The density of binding sites (Bmax) was 100 fmol/mg protein for the high and 466 fmol/mg protein for the low affinity binding site. 3H-tiotidine binds to a single population of binding sites with a KD of 1.0 nM and a Bma x of 27 fmo1/mg protein. These data suggest that both histamine H 1-and H 2-receptors coexist in the guinea pig myocardium with a significantly higher prevalence of the histamine H 1-receptor population.

Veterinary Anaesthesia and Analgesia, 2021

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Inflammopharmacology, Sep 1, 1996

Histamine is a normal constituent of mammalian heart. It affects cardiac function mainly through ... more Histamine is a normal constituent of mammalian heart. It affects cardiac function mainly through stimulating histamine H 1-and H2-receptor subtypes. The simultaneous activation of HI-and H2-receptors in the heart results in: a positive inotropic and chronotropic effect, a negative dromotropic effect, increased automaticity and increased coronary blood flow. HI-and H2-receptors have already been cloned from different, but not yet from cardiac, tissue. They are two independent molecular entities differing in the length of their amino acid sequence, pathways of transmembrane and intracelhilar signaling, characteristics of their binding sites and selectivity for the specific agonists and/or antagonists. Our results of radioligand binding studies show the presence in the heart of a high-affinity (KD 0.4 nmol/L and Bmax 100 fmol/mg of protein) and a lowaffinity (KD 4.5 nmol/L, Bm~ 466 fmol/mg of protein) HI-receptor-binding site and only a single population of less-abundant high-affinity H2-receptor binding sites (KD 1.0 nmol/L and Bm,~ 27 fmol/ mg of protein). The role of the histamine in cardiac pathophysiology is well established but the physiological role is unclear. The only proposed physiological role of histamine in the heart is the modulation of noradrenaline release from sympathetic nerve terminals, where H3-receptor subtypes might be involved.

Blood Cells Molecules and Diseases, May 1, 2009

Heparins (unfractionated and low molecular weight (LMWH) heparins) primarily used as anticoagulan... more Heparins (unfractionated and low molecular weight (LMWH) heparins) primarily used as anticoagulants, were found to be effective also in slowing down the development of some types of cancer. On the other hand, the number of microvesicles in the peripheral blood originating from the budding of cell membranes (mostly platelets) is increased in hypercoagulabile states as well as in cancer, indicating a possible common underlying mechanism. It was hypothesized that by mediating an attractive interaction between phospholipid membranes heparin suppresses microvesiculation and thereby acts as an anticoagulant and anti-tumor agent. In this work, the effect of LMWH nadroparin on phospholipid membranes was tested in vitro in a system of giant phospholipid vesicles (GPVs) created by electroformation and observed under the phase contrast microscope. Plasma of different blood donors containing different concentrations of nadroparin was added to the suspension of GPVs to induce adhesion between GPVs. The attractive interaction between membranes was assessed by measuring the average effective angle of contact between the adhered GPVs. It was found in healthy donors, in a donor with gastrointestinal cancer and in a donor with rheumatoid arthritis that adding therapeutic doses of nadroparin to the plasma samples enhanced adhesion of phospholipid membranes in a dose and time-dependent manner while nadroparin alone had no effect within the therapeutic concentration range. The results are in favor of the hypothesis that suppression of microvesiculation underlies both, the anticoagulant and the anti-tumor progression effect of heparin.

Autoimmunity Reviews, 2008

This article was published in an Elsevier journal. The attached copy is furnished to the author f... more This article was published in an Elsevier journal. The attached copy is furnished to the author for non-commercial research and education use, including for instruction at the author's institution, sharing with colleagues and providing to institution administration. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright

Blood Cells Molecules and Diseases, Jul 1, 2008

The Journal of Neuroscience, Mar 1, 2003

Astrocytes are non-neuronal cells in the CNS, which, like neurons, are capable of releasing neuro... more Astrocytes are non-neuronal cells in the CNS, which, like neurons, are capable of releasing neuroactive molecules. However, the mechanism of release is ill defined. In this study, we investigated the mechanism of release of atrial natriuretic peptide (ANP) from cultured cortical astrocytes by confocal microscopy. To study the discharge of this hormone, we transfected astrocytes with a construct to express pro-ANP fused with the emerald green fluorescent protein (ANP.emd). The transfection of cells with ANP.emd resulted in fluorescent puncta in the cytoplasm that represent secretory organelles. If ANP is released by exocytosis, in which the vesicle fuses with the plasma membrane, then the total intensity of the green fluorescing probe should decrease, whereas the vesicle membrane is incorporated into the plasma membrane. To monitor exocytosis, we labeled the membrane with the fluorescent styryldye FM 4-64, a reporter of cumulative exocytosis. The application of ionomycin to elevate cytoplasmic [Ca 2ϩ ] increased the fluorescence intensity of FM 4-64, whereas that of ANP.emd decreased. These effects were not observed in the absence of extracellular Ca 2ϩ , suggesting that ANP is released by regulated Ca 2ϩ-dependent exocytosis from astrocytes.

Inflammopharmacology, 1996

Advances in Planar Lipid Bilayers and Liposomes, 2009

Abstract Astrocytes, which are no longer considered as passive supportive cells of central nervou... more Abstract Astrocytes, which are no longer considered as passive supportive cells of central nervous system, actively participate in brain communication as well as take care for proper microenvironment, because they take up the excess of extracellular potassium ions and neurotransmitters. Neurotransmitter transporters are key elements in terminating synaptic activity of distinct neurotransmitters. They use energy stored in the electrochemical gradient of either sodium ions or protons across neuronal or glial cell membrane for uphill transport of neurotransmitters from extracellular to intracellular site. Sodium‐coupled neurotransmitter transporters belong to two distinct families of transporters of solute carrier proteins (SLC): SLC 1 which represents glutamate transporters and SLC6 to which the other neurotransmitter transporters belong. Apart from neurotransmitter transporters, there is another family in the SLC transporter super family that participates in movement of some monoamines across membranes, a SLC22 family. They act in a sodium‐ and chloride‐independent manner. Because of direct involvement of transporters in the availability of neurotransmitters, they represent a site of action of many present and future drugs. In the present review we would like to address the importance of neurotransmitter transporters on astrocytes in the regulation of synaptic signaling.

Cancer Research, 2009

Antitumor efficacy of intramuscular mIL-12 gene electrotransfer (EGT) in solid subcutaneous sarco... more Antitumor efficacy of intramuscular mIL-12 gene electrotransfer (EGT) in solid subcutaneous sarcoma tumors and their induced lung metastases, alone or combined with local tumor or lung irradiation was studied, and possible interaction between the treatment approaches evaluated. Lung metastases and subcutaneous tumors were induced by intravenous or subcutaneous injection of SA-1 or LPB tumor cells, respectively. Electrotransfer of mIL-12 was performed by intramuscular injection of plasmid DNA followed by local application of electric pulses. Mice bearing subcutaneous tumors were treated by mIL-12 EGT 3-times every second day. Tumor irradiation was performed 1 day after the first EGT. Treatment effectiveness was evaluated by tumor growth delay assay. Mice with induced lung metastases were treated by EGT 24 h before (prophylactic treatment) or at three different time points after the injection of cancer cells. Tumor irradiation was performed 3 days after first EGT. Eight or 14 days pos...

Pharmaceutics, 2021

The plasma concentration profile of bleomycin in the distribution phase of patients younger than ... more The plasma concentration profile of bleomycin in the distribution phase of patients younger than 65 years is needed to determine the suitable time interval for efficient application of electric pulses during electrochemotherapy. Additionally, bleomycin concentrations in the treated tumors for effective tumor response are not known. In this study, the pharmacokinetic profile of bleomycin in the distribution phase in 12 patients younger than 65 years was determined. In 17 patients, the intratumoral bleomycin concentration was determined before the application of electric pulses. In younger patients, the pharmacokinetics of intravenously injected bleomycin demonstrated a faster plasma clearance rate than that in patients older than 65 years. This outcome might indicate that the lowering of the standard bleomycin dose of 15,000 IU/m2 with intravenous bleomycin injection for electrochemotherapy is not recommended in younger patients. Based on the plasma concentration data gathered, a tim...

Proceedings for Annual Meeting of The Japanese Pharmacological Society, 2018

BMC Pharmacology and Toxicology, 2012