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A Kiss

Publications and source records attributed to A Kiss.

At least 55 records · Page 3Linked to original sources
PubMed2001

Gene expression of catecholamine synthesizing enzymes in A5 cell group and modulation of tyrosine hydroxylase mRNA by immobilization stress.

OBJECTIVE: The A5 group of noradrenergic neurons plays a key role in autonomic mechanisms like cardiovascular regulation, nociception and respiration. The aim of this work was to detect the gene expression of catecholamine synthesizing enzymes in A5 brain nuclei. METHODS: The gene expression of. tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH) and phenylethanolamine N-methyl-transferase (PNMT) in A5 brain nuclei was estimated. We also investigated various time intervals after the end of the single two-hour immobilization, as well as the effect of short-term repeated immobilization (120 min daily for 7 days) on tyrosine hydroxylase gene expression, the rate-limiting enzymes in catecholamines biosynthesis, in the A5 cell group. For all experiments, reverse transcription with subsequent polymerase chain reaction (RT-PCR) was used. RESULTS: As expected, we detected a clear signal for TH and DBH mRNA but no signal for PNMT mRNA. Both, single and repeated immobilization stress exposure increased significantly the gene expression of TH in A5 area. Maximal elevation in TH mRNA levels occurred after single immobilization for two hours and subsequent decapitation 24 hours later. CONCLUSIONS: In this study we detected for the first time the presence of DBH mRNA in micro dissected A5 cell group. We also showed how the gene expression of tyrosine hydroxylase changed with the function of time after the single immobilization exposure. Thus, TH mRNA in A5 cell group is modulated by immobilization stress in a time-dependent manner.

Animals↗
PubMed2001

Lesion of central part of the dorsomedial nucleus alters vasopressin but not corticotropin releasing hormone mRNA levels in rat hypothalamic paraventricular nucleus.

Functional significance of neural projections from the hypothalamic dorsomedial nucleus (DMN) to the paraventricular nucleus (PVN) was investigated using surgical lesion of the central part of the DMN. Under basal conditions, DMN lesion resulted in a decrease in magnocellular vasopressin (AVP) mRNA levels in the PVN, rise in pituitary proopiomelancortin (POMC) mRNA concentrations and elevated plasma corticosterone levels. Corticotropin-releasing hormone (CRH) mRNA levels remained unaffected. In sham operated animals, osmotic stress induced by hypertonic saline injection failed to modify AVP mRNA, but increased CRH and POMC mRNA levels and peripheral hormone release. The rise in CRH mRNA levels after osmotic stress was potentiated in DMN lesioned animals. Thus, the DMN participates in the control of hypothalamic peptide gene expression and pituitary adrenocorticotropic function.

Animals↗
PubMed2000

Daily profiles of arginine vasopressin mRNA in the suprachiasmatic, supraoptic and paraventricular nuclei of the rat hypothalamus under various photoperiods.

Daily rhythm of arginine vasopressin (AVP) mRNA levels in the suprachiasmatic nucleus (SCN) of rats maintained under a short, LD 8:16 photoperiod differed from that of rats maintained under a long, LD 16:8 photoperiod: under the short photoperiod the morning AVP rise occurred significantly later than under the long one. Daily profiles of AVP mRNA in the supraoptic and paraventricular nuclei were not rhythmic and AVP mRNA levels under LD 8:16 did not differ from those under LD 16:8. The data indicate that photoperiod affects selectively the clock driven AVP gene expression in the SCN.

Animals↗
PubMed2000

Molecular cloning and functional characterization of inhibitor-sensitive (mENT1) and inhibitor-resistant (mENT2) equilibrative nucleoside transporters from mouse brain.

Mammalian cells express at least two subtypes of equilibrative nucleoside transporters, i.e. ENT1 and ENT2, which can be distinguished functionally by their sensitivity and resistance respectively to inhibition by nitrobenzylthioinosine. The ENT1 transporters exhibit distinctive species differences in their sensitivities to inhibition by dipyridamole, dilazep and draflazine (human>mouse>rat). A comparison of the ENT1 structures in the three species would facilitate the identification of the regions involved in the actions of these cardioprotective agents. We now report the molecular cloning and functional expression of the murine (m)ENT1 and mENT2 transporters. mENT1 and mENT2 encode proteins containing 458 and 456 residues respectively, with a predicted 11-transmembrane-domain topology. mENT1 has 88% and 78% amino acid identity with rat ENT1 and human ENT1 respectively; mENT2 is more highly conserved, with 94% and 88% identity with rat ENT2 and human ENT2 respectively. We have also isolated two additional distinct cDNAs that encode proteins similar to mENT1; these probably represent distinct mENT1 isoforms or alternative splicing products. One cDNA encodes a protein with two additional amino acids (designated mENT1b) that adds a potential protein kinase CK2 phosphorylation site in the central intracellular loop of the transporter, and is similar, in this regard, to the human and rat ENT1 orthologues. The other cDNA has a 5'-untranslated region sequence that is distinct from that of full-length mENT1. Microinjection of mENT1, mENT1b or mENT2 cRNA into Xenopus oocytes resulted in enhanced uptake of [(3)H]uridine by the oocytes relative to that seen in water-injected controls. mENT1-mediated, but not mENT2-mediated, [(3)H]uridine uptake was inhibited by nitrobenzylthioinosine and dilazep. Dipyridamole inhibited both mENT1 and mENT2, but was significantly more effective against mENT1. Adenosine inhibited both systems with a similar potency, as did a range of other purine and pyrimidine nucleosides. These results are compatible with the known characteristics of the native mENT1 and mENT2 transporters.

5' Untranslated Regions↗
PubMed2000

[Fluorescence in situ hybridization in the diagnosis and follow-up of chronic myelogenous leukemia].

Chronic myelogenous leukaemia is a clonal myeloproliferative stem cell disease. Its cytogenetical hallmark is the Philadelphia chromosome (Ph) or the BCR/ABL fusion gene. Their identification is important both in the diagnosis and the follow-up of the disease. In our department we have investigated the BCR/ABL gene arrangement in 21 patients with fluorescence in situ hybridization. The aim of the analysis in freshly suspected patients without any previous therapy was to confirm diagnosis and mapping the ratio of Philadelphia positive cells. In contrast to the 95-100% Ph-positivity of mononuclear cells by classical cytogenetical examinations we found BCR/ABL gene arrangement only in various but always lower proportions. Therefore the latter examination gives a better representation of residual normal hemopoesis. Out of 9 patients who had received interferon treatment for at least 6 months, 4 gave a major, 4 a minor cytogenetical answer and in 1 case there was no cytogenetical response. Seven patients reached a complete and 2 a partial hematological remission. Among 5 other patients receiving interferon treatment, in 2 cases with double Ph-positivity we found a rapid progression. The data of 3 patients had to be excluded from the evaluation due to the so far short following time.

Diagnosis, Differential↗
PubMed2000

DNA bending induced by DNA (cytosine-5) methyltransferases.

DNA bending induced by six DNA (cytosine-5) methyltransferases was studied using circular permutation gel mobility shift assay. The following bend angles were obtained: M.BSP:RI (GG(m5)CC), 46-50 degrees; M.HAE:III (GG(m5)CC), 40-43 degrees; M.SIN:I (GGW(m5)CC), 34-37 degrees; M.SAU:96I (GGN(m5)CC), 52-57 degrees; M.HPA:II (C(m5)CGG), 30 degrees; and M.HHA:I (G(m5)CGC), 13 degrees. M. HAE:III was also tested with fragments carrying a methylated binding site, and it was found to induce a 32 degrees bend. A phase-sensitive gel mobility shift assay, using a set of DNA fragments with a sequence-directed bend and a single methyltransferase binding site, indicated that M.HAE:III and M. BSP:RI bend DNA toward the minor groove. The DNA curvature induced by M.HAE:III contrasts with the lack of DNA bend observed for a covalent M.HAE:III-DNA complex in an earlier X-ray study. Our results and data from other laboratories show a correlation between the bending properties and the recognition specificities of (cytosine-5) methyltransferases: enzymes recognizing a cytosine 3' to the target cytosine tend to induce greater bends than enzymes with guanine in this position. We suggest that the observed differences indicate different mechanisms employed by (cytosine-5) methyltransferases to stabilize the helix after the target base has flipped out.

5-Methylcytosine↗
PubMed2000

[Detection of minimal residual diseases in B-cell tumors using PCR specific for the immunoglobulin heavy chain gene].

In B-cell non-Hodgkin's lymphomas (NHL), clonal rearrangement of the immunoglobulin heavy chain (IgH) gene provides a useful marker for the detection of minimal residual disease (MRD) after treatment. To explore clinical usefulness of polymerase chain reaction (PCR) analysis of clonal IgH gene rearrangement in the detection of MRD a follow up study of 10 patients with B-cell NHL have been performed. At the time of diagnosis, tumor DNAs were PCR-amplified using sense primer specific for the heavy chain variable region (VH) and antisense primer specific for the heavy chain joining region (JH) of the IgH gene. The clonal rearrangement of IgH gene detected by PCR was used as clonal marker to determine MRD after treatment. In three cases, where clinical remission was not achieved, clonal IgH gene rearrangement was detected after the treatment. In seven cases, clinical remission was achieved after induction therapy but the PCR analysis revealed clonal IgH gene rearrangement in three of the cases. In all of the three cases, where MRD was detected by PCR, clinical relapse developed after 7-28 months of the therapy. In all cases that have relapsed, the IgH gene rearrangement was identical at the time of initial diagnosis and at the relapse. This study demonstrates that PCR analysis of clonal IgH gene rearrangement is a useful method to monitor and detect MRD before clinical relapse.

Biomarkers, Tumor↗
PubMed2000

[Preliminary results of the study of the relationship between cricopharyngeal incoordination and gastroesophageal reflux in infants].

The authors summarise the results of barium swallow examinations and polysomnographic studies performed on 66 infants (41 male, 25 female), average age 63 days (26-130 days). Oesophageal pH monitoring was also performed as part of the polysomnographic examination. The results showed the highest incidence of cricopharyngeal incoordination (CPI) in the 6-10 weeks age group. Although they failed to demonstrate statistical significance between CPI and increased gastro-oesophageal reflux, they consider the two entities to be most probably related. No relation was found between CPI and abnormal polysomnographic results. They give an overview of the literature on the pathology of the cricopharyngeal muscle and with regard to the lack of uniformity in the terminology of previous publications, they present their use of terminology.

Cricoid Cartilage↗
PubMed2000

Acute increase in blood flow to the rat bladder subsequent to partial bladder outlet obstruction.

Partial obstruction of the rat bladder outlet initiates a multi-step process during which the bladder progressively loses its functional ability. The first step in this progression is bladder hypertrophy; the organ dramatically increases in size and weight to compensate for the effects of obstruction. Unoperated female rats, age-matched, sham-obstructed rats, and rats that received a partial bladder outlet obstruction were studied. During the first 24 hours after partial bladder outlet obstruction, relative bladder blood flow was measured using a fluorescent microsphere infusion technique and laser Doppler imaging. Nitric oxide synthase (NOS) activities of control and obstructed rat bladder tissues were determined using an enzymatic assay that measures the conversion of (3)H-L-arginine to (3)H-L-citrulline. Using the microsphere infusion technique, a significant increase in blood flow to the obstructed rat bladder was observed during the first 24 hours after partial bladder outlet obstruction. Relative bladder blood flow increased approximately sixfold at 4 and 6 hours post-obstruction and remained elevated through 24 hours of obstruction. Sham operations (evaluated after 6 hours after surgery) resulted in a minor increase in blood flow that did not reach statistical significance. Relative blood flow to the spleen, measured in the same rats, was not significantly changed. Laser Doppler measurements also identified a significant increase in rat bladder blood flow after outlet obstruction and showed that increased blood flow could be detected as early as 1 hour post-obstruction. Interestingly, despite the significant differences in bladder blood flow between control and early post-obstructed rat bladders, NOS activities of control and obstructed rat bladders were comparable. The increase in bladder blood flow precedes the urothelial, fibroblast and smooth muscle cell hyperplasia, and the smooth muscle hypertrophy that occurs after obstruction. We propose that, in response to surgical induction of partial outlet obstruction, acute up-regulation of bladder blood flow may be an initiating factor for subsequent bladder cell proliferation and smooth muscle hypertrophy. Neurourol. Urodynam. 19:195-208, 2000.

Animals↗
PubMed2000

Role of alpha-1-adrenergic receptors in the regulation of corticotropin-releasing hormone mRNA in the paraventricular nucleus of the hypothalamus during stress.

1. The role of alpha1-adrenergic receptors on CRH mRNA levels in the PVN was studied in control and stressed rats receiving i.c.v. injections of the alpha1-adrenergic agonist, methoxamine, or the alpha1- antagonist, prazosin. 2. Plasma ACTH increased significantly 60 min and 4 hr after a single injection of methoxamine (100 microg, i.c.v.). No desensitization of this response was observed after repeated injections every 6 hr for 24 hr. Concomitantly, POMC mRNA in the anterior pituitary increased by 25% at 4 hr after a single injection and by 96% after repeated injections. 3. CRH mRNA levels in the PVN increased by 131% after repeated injections for 24 hr, but were unchanged 4 hr after a single injection. Central alpha-adrenergic blockade with prazosin did not prevent the increases in CRH mRNA following 4 hr of acute stress, but significantly reduced the increases observed 24 hr after an i.c.v. injection of 75 microg of colchicine or after repeated i.p. hypertonic saline injections every 8 hr. 4. These studies demonstrate that while alpha1-adrenergic receptors contribute to longterm increases of CRH mRNA levels in the PVN during prolonged stress, other factors are likely to be involved in the stimulation of CRH mRNA following acute stimulation.

Adrenergic alpha-Antagonists↗
PubMed2000

Increased leukocyte-platelet adhesion in chronic myeloproliferative disorders with high platelet counts.

The heterophilic adhesions between monocytes and platelets may result in the modification of both platelet and monocyte function. This mutual modification includes a greater activation of platelets with increased production of PDGF and other metabolites as well as an enhanced tissue factor expression of monocytes with greater activity in the circulation. The heterophilic aggregation has been well documented during extracorporal circulation, haemodialysis and in diabetic retinopathy. Here we provide evidence that there is significant increase of monocyte-platelet aggregates in disorders associated with high platelet counts, such as chronic myeloproliferative disorders. The presence of these heterophilic aggregates may contribute to the vascular complications observed frequently in polycythaemia vera and essential thrombocythaemia.

Adult↗
PubMed2000

Use of a platelet filter test in patients with thrombocytosis.

In the differential diagnosis of primary and secondary thrombocytosis platelet function tests may play an important role. We examined the applicability of a platelet filter test (shear-dependent platelet aggregation) as a tool, to differentiate primary thrombocytosis (cases with myeloproliferative disorders) from secondary (reactive) thrombocytosis. The test was carried out in 53 patients suffering from myeloproliferative disorders associated with primary thrombocytosis and in 21 patients with other diseases complicated by secondary thrombocytosis. Using citrate as anticoagulant, the sensitivity of the O'Brien's test proved to be 77.1%, and its specificity 94.4%. Using heparin as anticoagulant the sensitivity and specificity of the test were found to be also reliably high. Based on these studies we suggest the use of the O'Brien's filterometer as a screening test in the differential diagnosis in patients with elevated platelet count. In the case of normal results, the causes of reactive thrombocytosis should be clarified first, while with abnormal results, haematological examination of the patients should be performed.

Adenosine Diphosphate↗
PubMed2000

Alterations of P53 and RB genes and the evolution of the accelerated phase of chronic myeloid leukemia.

Using the single-strand conformation polymorphism and heteroduplex analyses, the P53 and RB genes were analyzed in cell samples from twenty-eight patients with chronic myeloid leukemia (CML) both at diagnosis and at the onset of accelerated phase (AP) of the disease. No alterations of the P53 or RB genes were found in any of the chronic phase (CP) samples. Structural abnormalities of the P53 gene were observed in ten of twenty-eight AP samples within exons 4, 5, 7 and 9. Of the ten cases of AP disease with altered P53 genes, five patients also suffered from the deletion of the other allele. Alterations of the RB gene could be detected in six AP samples, and aberrant band patterns were found in the analysis of exons 2, 3, 4, 6, 7, 13, 14, 17, 21 and 26. Among the six AP samples with structural abnormalities of the RB gene, two showed the loss of the other allele. It is of note that alterations of both P53 and RB genes were observed in two AP samples. Our data strongly suggest that abnormalities of the P53 and RB genes and acceleration of CML are linked events in some cases of AP.

Adult↗
PubMed2000

Myelofibrosis in systemic lupus erythematosus.

In this study we present a case of coexisting systemic lupus erythematosus (SLE) and myelofibrosis. Literature review supports the fact that the two diseases rarely occur together in the same patient. The young female patient studied was admitted with pancytopenia and a clinical picture which met the criteria of SLE. Histological examination of the bone marrow biopsy revealed severe myelofibrosis with hypocellularity of the myeloid cell lines. Treatment with immunosuppressive and colony stimulating factor led to slow but complete regeneration of the bone marrow and subsequently to an improved haematological status, and the patient was spared bone marrow transplantation.

Adolescent↗
PubMed1999

Fas antigen/CD-95 upregulation and activation during castration-induced regression of the rat ventral prostate gland.

BACKGROUND: Fas antigen/CD 95 is a 45-kDa transmembrane protein that can initiate intracellular signaling pathways, leading to apoptosis when it is clustered on the cell surface. A recent report claiming that the ventral prostate glands of lpr -/- mutant mice (lacking functional fas antigen) do not regress following castration prompted our analysis of the regressing rat ventral prostate gland for evidence that fas antigen might participate in the molecular process leading to prostate cell apoptosis after castration. METHODS: An RNase protection assay and Western blotting analysis were used to quantify fas antigen mRNA and protein expression in the regressing rat ventral prostate gland. Immunoprecipitates of fas antigen from membrane preparations made from control or castrated rat prostates were analyzed for coprecipitation of FADD and RIP proteins to assess the activation state of the fas antigen before and after castration. Finally, prostate tissues obtained from two different strains of lpr -/- mutant mice were analyzed for induced apoptosis after castration by the TUNEL staining method. RESULTS: Rat ventral prostate gland fas antigen mRNA and protein expression was upregulated approximately 3-5-fold in the 3-day castrated rat as compared to hormonally intact rats. Immunoprecipitates of fas antigen from membranes of ventral prostates from castrated rats contained significantly increased amounts of both FADD and RIP proteins when compared to those of intact or control operated rats. However, counts of TUNEL-labeled cells in the ventral prostate glands of castrated lpr -/- mice were not significantly different from those in castrated, genetically normal controls. Likewise, the morphology of apoptotic bodies formed in the prostates of castrated lpr -/- mice was indistinguishable from that in control animals. CONCLUSIONS: Fas antigen/CD-95, a protein that is involved in some forms of apoptosis, is upregulated during regression of the rat ventral prostate gland and becomes functionally "activated." However, our inability to distinguish any difference in the apoptosis rate or in the morphology of the apoptotic bodies formed in response to castration between lpr -/- mice and genetically normal controls indicates that, contrary to the prior report, functional fas protein is not required for castration-induced prostate cell apoptosis.

Animals↗