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- Ardhammar, Malin, 1970, et al.
(författare)
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In vitro membrane penetration of modified peptide nucleic acid (PNA)
- 1999
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Ingår i: Journal of Biomolecular Structure and Dynamics. - : Informa UK Limited. - 0739-1102 .- 1538-0254. ; 17:1, s. 33-40
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Tidskriftsartikel (refereegranskat)abstract
- Efficient cellular uptake is crucial for the success of any drug directed towards targets inside cells. Peptide nucleic acid (PNA), a DNA analog with a promising potential as a gene-directed drug, has been shown to display slow membrane penetration in cell cultures. We here used liposomes as an in vitro model of cell membranes to investigate the effect on penetration of a PNA molecule colvalently modified with a lipophilic group, an adamantyl moiety. The adamantyl attachment was found to increase the membrane-penetration rate of PNA three-fold, as compared to corresponding unmodified PNA. From the penetration behaviour of a number of small and large molecules we could conclude that passive diffusion is the mechanism for liposome-membrane passage. Flow linear dichroism (LD) of the modified PNA in presence of rod-shaped micelles, together with octanol-water distribution experiments. showed that the adamantyl-modified PNA is amphiphilic; the driving force behind the observed increased membrane-penetration rate appears to be an accumulation of the PNA in the lipid double layer.
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| 3. |
- Blom, René, et al.
(författare)
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Leiomyosarcoma of the uterus: A clinicopathologic, DNA flow cytometric, p53, and mdm-2 analysis of 49 cases
- 1998
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Ingår i: Gynecologic Oncology. - 0090-8258. ; 68:1, s. 54-61
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Tidskriftsartikel (refereegranskat)abstract
- AIM: The authors analyzed in a retrospective manner the prognostic significance of p53 and mdm-2 expression, DNA ploidy, S-phase fraction (SPF), and traditional clinical and pathological prognostic factors in patients with uterine leiomyosarcomas. MATERIAL: Forty-nine patients were diagnosed with uterine leiomyosarcoma (25 stage I, 4 stage II, 8 stage III, and 12 stage IV). DNA flow cytometric analysis and immunohistochemical staining for p53 and mdm-2 were performed on paraffin-embedded archival tissue from the uterine tumors. RESULTS: Of the 49 patients, 35 (71%) died of disease and 2 died of intercurrent disease. The 5-year survival rate was 33%. FIGO surgical stage, DNA ploidy, SPF, mitotic index, cellular atypia, and tumor grade obtained significance (P < 0.05) in a univariate survival analysis of the leiomyosarcomas. In a multivariate analysis with survival as the end point, stage was found to be the most important factor (P = 0.007); DNA ploidy (P = 0. 045) and SPF (P = 0.041) also had independent prognostic significance. For FIGO stage I tumors, DNA ploidy (P = 0.04) and tumor grade (P = 0.01) were statistically significant in a univariate analysis, while only grade had independent prognostic significance (P = 0.01) in a multivariate analysis. In a univariate analysis including only FIGO stage I and II tumors with disease-free survival as the end point, p53 overexpression (P = 0.0016), DNA ploidy (P = 0.042), and tumor grade (P = 0.008) obtained significance. In a multivariate analysis, only p53 had independent statistical significance (P = 0.01). All p53 immunopositive stage I-II tumors recurred within 28 months from diagnosis. CONCLUSION: This study found that stage represents the most important prognostic factor for uterine leiomyosarcomas. DNA ploidy and SPF had independent prognostic value. DNA flow cytometry is useful in gaining additional prognostic information. In stage I patients, tumor grade gives significant information regarding clinical outcome. In addition, p53 overexpression may predict a higher risk of recurrence in early stage leiomyosarcomas.
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- Blom, René, et al.
(författare)
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Malignant mixed Mullerian tumors of the uterus: a clinicopathologic, DNA flow cytometric, p53, and mdm-2 analysis of 44 cases
- 1998
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Ingår i: Gynecologic Oncology. - 0090-8258. ; 68:1, s. 18-24
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Tidskriftsartikel (refereegranskat)abstract
- AIM: The authors retrospectively analyzed the prognostic significance of p53, mdm-2, DNA ploidy, S-phase fraction (SPF), and traditional clinical and pathologic factors in patients with malignant mixed Müllerian tumors (MMMT) of the uterus. METHODS: Between 1970 and 1995, 44 uterine tumors were diagnosed as MMMT (21 stage I, 2 stage II, 10 stage III, and 11 stage IV). Thirty-two were homologous type and 12 were heterologous type. DNA flow cytometry and immunohistochemical analysis for p53 and mdm-2 overexpression were performed on paraffin-embedded archival tissue. RESULTS: 68% of the tumors were nondiploid and 61% had an SPF greater than 10%. Sixty-one percent overexpressed p53 and 25% were mdm-2-positive. Furthermore, 91% of the tumors had a mitotic count greater than 10/10 hpf and 95% had high-grade cytologic atypia. Twenty-seven (61%) patients died of tumor and 6 (14%) died of intercurrent disease. Eleven (25%) patients are alive with no evidence of disease. The median follow-up for patients still alive was 59 months (range, 28-178 months). The overall 5-year survival rate was 38%. In a univariate analysis that included stage, histologic type, DNA ploidy, SPF, p53, mdm-2, mitotic index, and age, and with survival as the end point, only stage reached statistically prognostic significance. CONCLUSION: The majority of the tumors had obvious signs of aggressiveness such as high grade, high mitotic count, nondiploid pattern, high SPF, and overexpression of p53. This study found that stage is the most important prognostic factor for survival in MMMTs of the uterus.
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| 5. |
- Malmström, Rickard E
(författare)
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Neuropeptide Y Y1 receptor mechanisms in sympathetic vascular control
- 1997
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- It was demonstrated that the Y1 receptor was the predominant vascular neuropeptide Y (NPY) receptor in pig kidney and hind limb as exogenous and endogenous NPY evoked vasoconstrictor responses that were almost or totally abolished by the selective non-peptide Y1 receptor antagonist, BIBP 3226. Furthermore, renal vasoconstriction was evoked by NPY and a peptide Y1 agonist, but not by a Y 2 agonist, and these responses were strongly reduced by another non-peptide Y, receptor antagonist, SR 120107A. Moreover, expression of Y1 receptors in pig kidney and renal arteries was indicated by reverse transcriptase-polymerase chain reaction (RT PCR) and mRNA for Y1 receptors was detected in small intrarenal arteries with in situ hybridization. The NPY receptor population in the pig spleen seems to consist of both Y1 and Y2 receptors, since peptide agonists with preference for either subtype evoked splenic vasoconstriction. Splenic vasoconstriction evoked by the Y1 agonist was markedly reduced by SR 120107A. RT-PCR indicated expression of both Y1 and Y2 receptors in pig spleen and the existence of splenic Y2 receptors was also demonstrated with membrane and autoradiograpbic receptor binding. The predominant NPY receptor in both dog spleen and kidney is the Y1 receptor as demonstrated by in vivo studies, RT-PCR and receptor binding. The Y1-selectivity of SR 120107A was demonstrated by the fact that the compound displaced binding of an iodinated Y1, but not Y2, receptor ligand from membranes and sections of pig and dog spleen. Moreover, both SR 120107A and BIBP 3226 potently displaced tritiated BIBP 3226 binding from Y1 receptors in dog spleen. Increasing concentrations of BIBP 3226 caused a rightward shift in the concentration-response curves to NPY without influencing the maximal NPY-evoked contraction in guinea-pig vena cava. The antagonism appeared competitive as the slope (0.84) of the Schild plot was not significantly different from unity, with a pA2 value of 8.0. SR 120107A appeared as effective as BIBP 3226 in antagonizing NPY-evoked contractions in this vessel. SR 120107A potently inhibited Y1 receptor mediated vasoconstriction in the pig in vivo, without influencing vascular responses exerted via Y2, a, P2X1 and angiotensin II receptors. In addition, the Y, receptor antagonism of SR 120107A was of long (>3h) duration in vivo. BIBP 3226 exerted dose-dependent and equal antagonism on vascular responses to both endogenous and exogenous NPY in the pig in vivo. The elimination of BIBP 3226 from plasma fit a two-compartment model with half-lives of 2 and 20 min for the A- and B- phase, respectively. The final pharmacological evidence for NPY as a mediator of sympathetic vasoconstriction was presented. Thus, neurogenically released NPY mediates long-lasting contraction of the guinea-pig caval vein in vitro, as shown by the inhibitory effects of both BIBP 3226 and SR 120107A. In the presence of either antagonist, only an initial rapid adrenergic phase of contraction remained upon high frequency transmural electrical field stimulation in this vessel. The neurogenic contractions were largely unaffected by the S-enantiomer to BIBP 3226, BIBP 3435, which is virtually inactive on Y1 receptors. Evidence was also presented for the involvement of NPY in nonadrenergic sympathetic vasoconstriction evoked in the reserpine-treated pig in vivo. Thus, SR 120107A strongly reduced the long-lasting phase of vasoconstriction evoked in nasal mucosa and hind limb by high frequency sympathetic nerve stimulation, leaving merely an initial rapid phase of constriction. Furthermore, the reserpine-resistant sympathetic vasoconstriction in pig kidney was almost abolished by SR 120107A, whereas both the peak and duration of this response were reduced in the spleen. In contrast, the role of NPY in sympathetic vascular control is less obvious in the control pig, in which noradrenaline (NA) levels are intact and the NPY release is smaller due to prejunctional a2-receptor regulation. Reperfusion after two h of renal ischaemia was associated with venous overflow of NA, but not of NPY-like immunoreactivty (Ll). In addition, the renal sympathetic nerve-evoked overflow of NA, but not of NPY-LI, was reduced in parallel with reduced renal vasoconstrictor responses to nerve activation and exogenous agonists. The vascular responses as well as the nerve-evoked overflow of NA were partially restored a further two h after reperfusion. No overflow of either NA or NPY-LI was seen upon reperfusion after 15 min of renal ischaemia but an enhanced overflow of NPY-LI, but not NA, was observed upon sympathetic nerve stimulation and this was paralleled by an augmented vasoconstnctor response that in turn was significantly inhibited by BIBP 3226. Furthermore, the renal vasoconstrictor response to Y, receptor activation by exogenous agonists was markedly prolonged after 15 min ischaemia and this prolonged response was nearly abolished by BIBP 3226. These results suggest that, presumably due to an impaired local degradation, the role of neurogenically released NPY in renal sympathetic vasoconstriction is enhanced after short-term ischaemia compared to control conditions. It is concluded that NPY may serve as a sympathetic mediator of vasoconstriction, preferentially acting on the Y1 receptor. The role of NPY in sympathetic vascular control is enhanced after reserpine treatment and short-term ischaemia, but is less obvious in the control situation. Furthermore, BIBP 3226 and SR 120107A are selective Y, receptor antagonists both in vitro and in vivo.
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