Human biliverdin reductase, a previously unknown activator of protein kinase C betaII

Human biliverdin reductase (hBVR), a dual specificity kinase (Ser/Thr/Tyr) is, as protein kinase C (PKC) betaII, activated by insulin and free radicals (Miralem, T., Hu, Z., Torno, M. D., Lelli, K. M., and Maines, M. D. (2005) J. Biol. Chem. 280, 17084-17092; Lerner-Marmarosh, N., Shen, J., Torno, M. D., Kravets, A., Hu, Z., and Maines, M. D. (2005) Proc. Natl. Acad. Sci. U. S. A. 102, 7109-7114). Here, by using 293A cells co-transfected with pcDNA3-hBVR and PKC betaII plasmids, we report the co-immunoprecipitation of the proteins and co-purification in the glutathione S-transferase (GST) pulldown assay. hBVR and PKC betaII, but not the reductase and PKC zeta, transphosphorylated in assay systems supportive of activity of only one of the kinases. PKC betaII K371R mutant protein ("kinase-dead") was also a substrate for hBVR. The reductase increased the Vmax but not the apparent Km values of PKC betaII for myelin basic protein; activation was independent of phospholipids and extended to the phosphorylation of S2, a PKC-specific substrate. The increase in substrate phosphorylation was blocked by specific inhibitors of conventional PKCs and attenuated by sihBVR. The effect of the latter could be rescued by subsequent overexpression of hBVR. To a large extent, the activation was a function of the hBVR N-terminal chain of valines and intact ATP-binding site and the cysteine-rich C-terminal segment. The cobalt protoporphyrin-activated hBVR phosphorylated a threonine in a peptide corresponding to the Thr500 in the human PKC betaII activation loop. Neither serine nor threonine residues in peptides corresponding to other phosphorylation sites of the PKC betaII nor PKC zeta activation loop-derived peptides were substrates. The phosphorylation of Thr500 was confirmed by immunoblotting of hBVR.PKC betaII immunocomplex. The potential biological relevance of the hBVR activation of PKC betaII was suggested by the finding that in cells transfected with the PKC betaII, hBVR augmented phorbol myristate acetate-mediated c-fos expression, and infection with sihBVR attenuated the response. Also, in cells overexpressing hBVR and PKC betaII, as well as in untransfected cells, upon treatment with phorbol myristate acetate, the PKC translocated to the plasma membrane and co-localized with hBVR. hBVR activation of PKC betaII underscores its potential function in propagation of signals relayed through PKCs.     

Sequence stratigraphy of Eocene incised valley clastics and associated sediments,Island of Rab,northern Adriatic Sea,Croatia

Clastic sediments of Middle–Late Eocene age were studied on the Island of Rab (northern Adriatic Sea, Croatia) in order to reconstruct their depositional history, depositional environments, and geometry of sandstone bodies. Detailed outcrop logging and mapping revealed the response of depositional systems to frequent relative sea-level changes, which initiated significant basinward and landward shifts of facies, respectively. Tidal sandstones are commonly underlain by shoreface sandstones, and overlain by offshore sandy marls, whereas the latter are again overlain by shoreface sandstones. Major relative sea-level falls initiated basinward shift of depositional systems and the incision of incised valleys or estuaries, and consequently truncated the underlying shelf sediments. In some cases, the accelerated sea-level fall caused rapid shoreface progradation which is interpreted as a forced regression. Relative sea-level rise caused flooding of the incised relief, and deposition of tidal sandstone bodies which overlie type-I sequence boundaries. The coarse lag sediment of these sequence boundaries locally disappears laterally, and the boundary is granulometrically less prominent. All of the major bounding surfaces have been recognized in the sections studied, although the maximum flooding surface is recognized as a thin “zone” instead of a single surface. Altogether, 28 complete sequences, and 15 parasequences are recognized in the informal unit of the Lopar sandstones, documenting the depositional response to high-frequency relative sea-level oscillations. They have so far not been recognized in the Eocene of the eastern Adriatic region.     

Gap regeneration and replacement patterns in an old-growth <Emphasis Type="Italic">Fagus</Emphasis>–<Emphasis Type="Italic">Abies</Emphasis> forest of Bosnia–Herzegovina

We examined the influence of small-scale gap disturbances on stand development and tree species coexistence in an old-growth Fagus sylvatica–Abies alba forest in the Dinaric Mountains of Bosnia–Herzegovina. The structure and composition of tree regeneration in gaps were compared to the forest as a whole, and the influence of gap size on the density and composition of regeneration was assessed. Transition probabilities were also calculated from gapfillers in different life stages to examine canopy replacement patterns. The structure and composition of tree regeneration were similar between gaps and the forest as a whole, and there was no relationship between overall regeneration density and gap size, indicating most individuals established prior to gap formation. Likewise, there was no strong evidence of gap-size partitioning for shade tolerant F. sylvatica and A. alba, although less tolerant Acer pseudoplatanus only recruited to taller life stages in larger gaps. Transition probabilities calculated from the seedling and sapling data suggest that most gaps will be captured by F. sylvatica, while probabilities based on pole-sized gapmakers indicate both A. alba and F. sylvatica will be maintained in the canopy. We suggest that gaps primarily play a role in reorganizing advance regeneration, and that coexistence of shade tolerant F. sylvatica and A. alba is more likely related to their differential ability to tolerate shaded understory conditions, particularly during larger life stages, rather than gap-size partitioning.     

Response to hyperoxia is associated with similar ho-1 gene expression level in lungs of aging CBA mice of both sexes

Beside classical antioxidative enzymes, the response to hyperoxia might be mediated via regulation of other systems, such as heme oxygenase (HO). Ho-1 gene expression is found to be upregulated by hyperoxia in all groups of mice, while HO-1 protein isoform was increased only in 4 months old male mice. In steady-state conditions ho-1 and ho-2 gene expression remained unchanged irrespective of sex or age, which was not the case with protein level of both isoforms. This study suggests that in lungs of CBA mice the response to oxidative stress may be mediated through the interaction of other systems such as heme oxygenase, primarily via upregulation of ho-1 gene expression in both sexes. Contrary to our previous study in liver of hyperoxia treated mice, current results might imply that at conventional oxygen conditions lungs of female mice with the emphasis on aging females, are better prepared for oxidative stress conditions through the increase of HO-activity.     

Axial eye length after retinal detachment surgery

Changes in the eye axial diameter were studied to assess the eye globe impact of conventional operation for retinal detachment. The study included 69 eyes in 69 patients operated on for rhegmatogenous retinal detachment. There were 46.4% of men and 53.6% of women, mean age 52.7 (+/- 15.21) years. Results of preoperative and postoperative ultrasonographic measurement of axial diameter are presented. The mean preoperative and postoperative eye axial diameter was 23.69 (+/- 1.84) mm and 24.43 (+/- 1.91) mm, respectively. Postoperative results showed the axial eye length to increase by a mean of 0.74 (+/- 0.44) mm, yielding a statistically significant difference from the preoperative measurement (p < 0.001). The mean myopia induced by this eyeball elongation was 1.77 D. The encircling band with and without segmental buckling used in surgical repair of retinal detachment creates circular and segmental indentation of the eyeball, thus increasing its axial length. The myopia induced by elongation of the eyeball results in considerable myopia, which requires appropriate correction in the early postoperative period to achieve favorable vision rehabilitation.     

Influence of psychosocial work-related factors on conventional risk factors of ischemic heart disease and homocysteine in Slovenian male workers

The influence of psychosocial work-related factors on the conventional risk factors of ischemic heart disease (IHD), particularly on the lipid changes and their effect on homocysteine is studied in this paper. Employed males aged 35 to 55 with angina pectoris or a myocardial infarction (IHD group) were compared to a group of individuals without ischemic heart disease (Control Group). Psychosocial factors were assessed using a Swedish Theorell questionnaire. The IHD Group was found to be at a higher risk of IHD due to higher work demands (OR = 1.25), worse job control (OR = 1.23), frequent smoking (OR = 2.2), leadership positions (OR = 3.97), higher BMI (p = 0.059) and higher levels of triglycerides (p = 0.005) and LDL-cholesterol (OR = 1.65). The level of HDL-cholesterol was significantly lower (1.0 vs. 1.4 mmol/L, p < 0.001, OR = 1.64), while the level of C-reactive protein (9.1 vs. 1.8 mg/L) and Interleukin-6 (6.5 vs. 1.6 ng/L) was higher. Homocysteine levels showed borderline significance (p = 0.056). Our study suggests a possible influence of psychosocial work-related factors on IHD risk factors, most of all on low HDL-cholesterol. No connection was found between psychosocial factors and the homocysteine level, shown to be an IHD risk factor at lower levels of approximately 10 micromol/L.     

Effectiveness of latanoprost (Xalatan) monotherapy in newly discovered and previously medicamentously treated primary open angle glaucoma patients

We evaluated the effectiveness of latanoprost (Xalatan) monotherapy in primary open angle glaucoma (POAG). Latanoprost is a prostaglandin analogue, the pure 15(R) epimer of 13,14-dihydro-17-phenyl-18,19,20-trinor-PGF2alpha-isopropyl ester. As a prodrug it is being activated by enzymatic hydrolysis in the cornea after which it becomes active acid of latanoprost. Latanoprost is lowering the intraocular pressure (IOP) by increasing the uveoscleral outflow. In this study, latanoprost was used once daily as monotherapy what offers much better compliance for the patients than other combinations of drugs, preserving good IOP control. Based on the significant reduction of the IOP, measured on the day 60 of the trial (mean change in IOP was -5.1 mmHg, with 95% confidence interval in range from -5.6 to -4.5), it is concluded that use of latanoprost is advisable when calculating better IOP control, few side-effects and reductions in costs of potential surgical procedures.     

The expression of interleukin-1 alpha, TNF and VEGF in corneal cells of patients with bullous keratopathy

Bullous keratopathy (BK) is a chronic corneal edema with or without subepithelial bullae as a result of a loss of the endothelial cells. 15 patients with BK after cataract surgery with intraocular lens implantation, due to Fuchs dystrophy (n = 3) or corneal endothelial trauma (n = 12) were included in the study. All patients were treated by amniotic membrane transplantation (AMT). Corneal epithelial cells in patients suffering from BK secreted 3.91 +/- 3.09 pg/mL of IL-1 alpha, 4446 +/- 16.8 pg/mL of TNF and 81.43 +/- 37.81 pg/mL of VEGF-I. Levels of all 3 investigated cytokines were significantly higher as compared to controls (p < 0.005). Amniotic membranes that were used to treat investigated patients contained 638.98 +/- 613.98 pg/mL of IL-1ra, 0.026 +/- 0.009 pg/mL of sTNF and 81.39 +/- 21.01 pg/mL of VEGF-R. Beneficial clinical effect of the AMT in treating BK could be explained by its natural production of pro-inflammatory cytokine antagonists such as IL-ra, sTNF antagonist and VEGF-R.     

Radiofrequency ablation as locoregional therapy for unresectable hepatic malignancies: initial results in 24 patients with 5-years follow-up

Radiofrequency ablation (RFA) is one treatment modality for unresectable liver metastases. Patients with hepatic malignancies (n = 24) underwent elective RFA. All tumors were ablated with a curative intent, with a margin of 1 cm, in a single session of RFA. The median diameter of tumor was 3.1 cm (range 1.7-6.9 cm). Studied patients were not candidates for resection due to multifocal hepatic disease, extrahepatic disease, proximity to major vascular structures or presence of cirrhosis with functional hepatic reserve inadequate to tolerate major hepatic resection. Complete tumor necrosis was achieved in 87.5% and tumor recurred in 3 patients (12.5%) with lesions larger than 5 cm. Distant intrahepatic recurrence was diagnosed in another 4 (16.7%). Distant metastases were found in 7 (29.2%) patients. Four of these 7 patients had also distant intrahepatic recurrence of disease. Two and 5-years survival rates were 41.7% (10 patients) and 8.3% (2 patients) respectively. RFA is safe and effective option for patients with unresectable hepatic malignancies smaller than 5 cm without distant metastatic disease. RF ablation resulted in complete tumor necrosis in 87.5% with 2 and 5-years survival rates much higher than with chemotherapy alone or only supportive therapy, when survival is measured in weeks or months. If RFA is unavailable, percutaneous ethanol injection therapy can be done but with inferior survival rates.