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Wall shear stress (WSS) is a relevant hemodynamic indicator of the local stress applied on the endothelium surface. More specifically, its spatiotemporal distribution reveals crucial in the evolution of many pathologies such as aneurysm, stenosis, and atherosclerosis. This paper introduces a new solution, called PaLMA, to quantify the WSS from 4D Flow MRI data. It relies on a two-step local parametric model, to accurately describe the vessel wall and the velocity-vector field in the neighborhood of a given point of interest. Extensive validations have been performed on synthetic 4D Flow MRI data, including four datasets generated from patient specific computational fluid dynamics simulations on carotids. The validation tests are focused on the impact of the noise component, of the resolution level, and of the segmentation accuracy concerning the vessel position in the context of complex flow patterns. In simulated cases aimed to reproduce clinical acquisition conditions, the WSS quantification performance reached by PaLMA is significantly higher (with a gain in RMSE of 12 to 27%) than the reference one obtained using the smoothing B-spline method proposed by Potters et al. (2015) method, while the computation time is equivalent for both WSS quantification methods., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: To explore the possible etiology of multiple osteomata on a skull and long bones from an individual from a medieval site in Tuscany, Italy., Materials: Human skeletal remains dating to the 10 th -12 th century AD from the parish church of S. Pietro in Pava, in the province of Siena (Tuscany, Central Italy)., Methods: Macroscopic and imaging analyses (Cone Beam Computed Tomography)., Results: Nine round-shaped new bone formations are observed on a female individual aged 40-50 years. The lesions have a smooth surface and range from 2.2-6 mm in diameter., Conclusions: Cone Beam Computed Tomography confirmed that the lesions were composed of compact bone. Macroscopic and radiological features suggest the presence of nonsyndromic multiple osteomata., Significance: Single cranial osteomata are commonly observed in osteoarchaeological remains, but multiple osteomata are rare and might assist in our understanding of neoplastic conditions in the past., Limitations: The lack of soft tissues prevents the diagnosis of complex disorders, such as the Gardner syndrome, which is characterised by multiple osteomata and polyposis of the colon., Suggestions for Further Research: Careful investigation and reporting of all neoplastic lesions in ancient human remains in order to increase our knowledge about the etiology in past human populations., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: This study was designed to determine the debated prognostic significance of reverse transcriptase-polymerase chain reaction (RT-PCR) positivity in melanoma patients' sentinel lymph node (SLN) negative by conventional histopathology (PATH)., Patients and Methods: Patients with primary stage I-II cutaneous melanoma underwent radioguided sentinel lymphadenectomy. Their SLNs were assessed for tyrosinase (Tyr) and melanoma antigens recognized by T-cells (MART-1) mRNA expression using RT-PCR, in parallel with hematoxylin and eosin staining and immunohistochemistry. Tyr and MART-1 expression in the SLNs were correlated with PATH assay results, standard prognostic factors, time to progression and overall survival., Results: Twenty-three of the 124 patients (18.5%) had positive SLNs by both PATH and RT-PCR (PATH+/PCR+). Sixteen patients (13%) were negative by PATH and positive by RT-PCR (PATH-/PCR+). Eighty-five patients (68.5%) had SLNs that were negative by both PATH and RT-PCR (PATH-/PCR-). At a median follow-up of 30 months, recurrence rates among the three cohorts were statistically different (PATH+/PCR+, 60%; PATH-/PCR+, 31%; PATH-/PCR-, 9.4%). Seven of 23 (30%) and two of 16 (12.5%) patients died in the PATH+/PCR+ and PATH-/PCR+ SLN groups, respectively, whereas no patient died in the PATH-/PCR- SLN group., Conclusions: RT-PCR is more sensitive than PATH to detect SLN metastases and it is a reliable predictor of disease relapse in stage I-II melanoma patients.

We used a model of crush-induced regeneration in rat in order to characterize biochemically and histologically the implication of protein kinase C (PKC) in muscle repair after damage. In this model, slow soleus and fast extensor digitorum longus (EDL) muscle regeneration proceed differently. PKC activity has been assayed in regenerating muscles and their intact contralateral during the first 14 days following crushing. Degeneration (myolysis) occurring shortly after crush was associated with a marked down-regulation of the enzyme in both wound muscles and notable increase in the corresponding contralateral muscles. Muscle fiber reconstruction in EDL was associated with a rise in PKC activity which peaked at day 7 in regenerating muscle where it was twice higher than in intact muscle. At variance, muscle PKC activity in soleus increased slower than that of EDL and reached later intact level. Western blot analysis and immunohistochemical studies of representative members of the three PKC subfamilies were performed. All the isoform tested were much less expressed in regenerating than in control intact muscles suggesting that the overall PKC activity in regenerating muscles was more activable than in controls. We have shown that PKC isoforms were sequentially expressed during regeneration in both muscle types. PKC theta; being present the earliest, then delta, epsilon and alpha and finally zeta, beta and eta. Some isoforms were differentially expressed according muscle type. PKC delta being more expressed in soleus whereas beta and eta appeared earlier in EDL. Histochemical studies have revealed that the isoforms were differently localized in muscle tissue and that fiber regeneration was associated with PKC alpha translocation from sarcoplasma to sarcolemma. Together these data have shown that multiple PKC isoforms are implicated in the regenerative process acting at different in times and location and suggesting that individual isoform may fulfill distinct functions.

Protein kinase C (PKC), a key component of the signaling pathways leading to proliferation and differentiation, consists of a family closely related serine/threonine protein kinases. The mRNA expression of these PKC isoforms has been characterized during hematopoietic differentiation. Using the reverse-transcriptase polymerase chain reaction technique, we have analyzed the levels of isoform transcripts in bone marrow CD34(+) hematopoietic progenitors and their progeny differentiated along erythroid, megakaryocyte, or granulocyte/monocyte lineages, upon exposure to growth factors. In contrast with isoforms alpha, beta(I), beta(II), delta, and epsilon, ubiquitously expressed, isoforms theta, eta/L, zeta, and iota/lambda exhibited a lineage-restricted expression. These qualitative changes, which allow to distinguish the erythroid and megakaryocyte phenotypes from the granulocyte/monocyte phenotype, include zeta exclusively upregulated in granulocytes/monocytes and theta, eta/L, and iota/lambda exclusively expressed in megakaryocytes and erythroblasts. In contrast, erythroblasts and megakaryocytes, which supposedly share a common bipotential progenitor, displayed only quantitative changes. These results evidence the selective expression of PKC isoforms at transcriptional and/or posttranscriptional levels in hematopoietic progenitors induced to differentiate, which may suggest a differential contribution of individual isoforms to cellular signaling., (Copyright 1999 Academic Press.)

Parkinson's disease (PD) is a neurodegenerative disease of the central nervous system (CNS), in which the cytokine network may be deranged, leading to an altered immunoregulation. Tumor necrosis factor(TNF)-alpha, a cytokine with pleiotropic neuroimmune effects, has specific receptors on human lymphocytes, as well as on other cell types, even in the CNS. The aim of the present study was to assay TNF-alpha binding on peripheral blood T cells from PD patients, as compared with healthy subjects. We found on T lymphocytes from parkinsonian patients significantly more TNF-alpha receptors than on those from controls (B (max): 637+/-23 vs. 131+/-6 (mean+/-S.E.M.) receptors/cell). Such TNF-alpha binding sites are of the same type in patients and healthy subjects (K(d): 66.8+/-5.1 vs. 70.7+/-5.6 (mean+/-S.E.M.) pM). These results are discussed in terms of PD immunopathogenesis, since it has been reported that activated T lymphocytes have increased amounts of TNF-alpha receptors.

All-trans retinoic acid (RA) activates brain protein kinase C (PKC) in a unique fashion. Co-factors such as Ca2+ or PtdSer are not required for histone phosphorylation. Binding experiments have provided evidence that RA does not act as a phorbol-ester-like activator. However, phorbol esters synergistically enhance this activation in a dose-dependent manner and increase the reaction rate up to five-fold when combined with 10 microM RA. Phospholipid-interacting drugs such as phenothiazines and 1-N-(6 aminohexyl) 5-chloro-1-naphthalene-sulfonamide (W7), which compete with PtdSer and inhibit phorbol ester/PtdSer-mediated activation, have potentiating effects on the RA-mediated reaction. RA elicits Ca(2+)-dependent PKC autophosphorylation. The activation resulting from the combined treatment with PtdSer and RA is more than additive in the presence of Ca2+, indicating that PtdSer- and RA-binding sites are distinct. RA shares several characteristics of activation with sodium deoxycholate and arachidonic acid. These present results suggest that the direct activation of PKC may have physiological and/or pharmacological relevance in the signaling triggered by retinoids.

Protein kinase C (PKC) activity was examined in the CNS of the newt Pleurodeles waltlii undergoing regeneration after limb amputation. In the spinal cord and brain of control newts, the level of PKC activity was virtually the same for the cytosolic and the particulate fractions. At days 7 and 14 after amputation of two limbs, a twofold increase in overall PKC activity occurred in the spinal cord and accounted for increased membrane-bound activity, while cytosolic activity was not significantly impaired. In contrast, overall PKC activity was not affected in brain. However, a twofold increase in the brain particulate fraction occurred at day 14 while cytosolic activity decreased proportionately. Similar alterations were observed in newts undergoing one or multiple limb amputations. Such changes in PKC activity neither occurred in the CNS of newt after limb denervation nor in the CNS of limb amputated frog Rana temporaria, an Amphibian which is unable to regenerate. Taken together, these results provide evidence that PKC of the CNS is involved in the regeneration process of newts. Changes in activation-associated PKC distribution proceeded through different mechanisms: long-lasting increase in membrane bound activity with a net increase of overall activity in the spinal cord, and long-term redistribution of enzyme activity to the particulate fraction in brain.

Unlike unsaturated fatty acids, which almost fully activated purified brain protein kinase C in a phosphatidylserine- and Ca2(+)-free reaction, related methyl esters were poorly active in vitro. In contrast, methyl arachidonate was revealed to be as potent as arachidonic acid in activating protein kinase C in intact platelets. Arachidonic acid-mediated activation peaked at 20 s while methyl arachidonate-mediated activation plateaued at 2 min when both lipids were added at 50 microM. At concentrations higher than 0.3 mM, all tested unsaturated fatty acids and related methyl esters were weak activators of the enzyme, with the exception of linolenic acid and methyl linolenate which evoked strong enzyme activation. However, inhibitors of arachidonate metabolism blocked both arachidonic-acid and methyl-arachidonate-induced responses. At 5 microM arachidonic acid and methyl arachidonate, protein kinase C activation was due to a cyclooxygenase product(s) whereas at 50 microM the lipoxygenase pathway was mostly involved in the reaction. Therefore, arachidonic acid and its methyl ester activate protein kinase C in platelets mainly through action of their metabolites and eicosanoid synthesis. It is suggested that such indirect protein kinase C activation may account for the tumor-promoting activity of unsaturated fatty acids and related methyl esters.

The signaling pathways which transfer information into the cell form a tissue-specific network. Protein kinase C (PKC) belongs to the inositol 1, 4, 5 trisphosphate/diacylglycerol (IP3/DG) pathway and plays a key role in cell regulation. The enzyme controls cell growth and functions through a set of negative and positive regulatory mechanisms. Some tumor promoters such as phorbol esters activate PKC by acting at the DG binding site. Others do not compete with DG and either activate PKC in the absence of phospholipids, such as arachidonic acid and bile salts, or require the presence of phospholipids, for instance a number of organic solvents. However, some promoters do not directly activate the enzyme although some of them appear to act elsewhere in the IP3/DG signaling pathway. The possibility that tumor promoters impair the expression of PKC is discussed.

In human platelets, thrombin activates Ca2+-activated, phospholipid-dependent protein kinase (protein kinase C) and mobilizes Ca2+ concomitantly, whereas 12-O-tetradecanoylphorbol-13-acetate (TPA) may be intercalated into membranes and directly activates protein kinase C without mobilization of Ca2+ in sufficient quantities. A series of experiments with TPA and Ca2+-ionophore (A23187) indicates that activation of protein kinase C is a prerequisite requirement for release of serotonin, and that this enzyme activation and Ca2+ mobilization act synergistically to elicit a full cellular response. Both cyclic AMP and cyclic GMP inhibit activation of protein kinase C by prohibiting the signal-dependent breakdown of inositol phospholipid to produce diacyl-glycerol, but none of these cyclic nucleotides prevents the TPA-induced activation of this enzyme.

The major interaction site for tumor-promoting phorbol esters is the calcium-activated, phospholipid-dependent protein kinase (protein kinase C), a key-element in signal transduction. Binding of phorbol esters results in enzyme activation which mediates, at least in part, the action of these agents. We have investigated the effects of tumor promoter chloroform on protein kinase C activity. Like thrombin and 12-O-tetradecanoylphorbol-13-acetate (TPA), chloroform was able to activate protein kinase C in intact rabbit platelets. In addition, chloroform stimulated enzyme activity as well as TPA binding capacity in cell-free system. Scatchard analysis of the data has shown that chloroform increased the number of phorbol ester binding sites. Structurally related compounds, carbon tetrachloride and methylene chloride, activated the enzyme similarly.

Phorbol esters and diacylglycerols activate protein kinase C but specific structural parameters appear to be required for the enzyme activation. We have analyzed the conformation of potent and not potent diacylglycerols and phorbol esters. The orientation of the CH20H group at C3 of 1,2 diolein is remarkably similar to that of the same group at C-20 of 4 beta phorbol didecanoate and crucial for potency in activating the enzyme. Our data suggest that the new conformational approach here described could be used to rationally design specific inhibitors preventing the effects of tumor promoters and to predict the structure of potential tumor promoters.

Thermal tolerance was tested in three developmental stages of the surf clam Spisula solidissima: cleavage stages, trochophore , and straight hinge larvae. Experiments were designed to simulate larval entrainment in the cooling system of a power plant. Eleven different temperatures were investigated from 20.2 to 43 degrees C. Exposure times varied from 1 min to 6 hr and following each of the (88) different exposures, larvae were returned to the incubation temperature for a further period of development which facilitated differentiation of dead and live animals. Pooled mortality data from triplicate experiments (for each larval state) were subjected to a stepwise regression analysis (percentage mortality on temperature and time). Equations were derived from the regression program comprising first-, second-, and third-order terms for temperature and time, and these were used to generate response surfaces relating mortality to temperature-time exposure. As with earlier work on Mulinia , the term (temperature) provides the best single predictor of larval mortality. Spisula is the only fully marine bivalve species so far subjected to this type of thermal tolerance test and is clearly the most temperature sensitive of all species investigated to date.

3-hydroxy-3-methylglutaryl-coenzyme A reductase (EC 1.1.1.3.4.) activity and cell membrane fluidity measured by fluorescence polarization using 1,6 diphenyl, 1,3,5-hexatriene as fluorescent probe have been concomitantly examined in HTC hepatoma cells, both in relation to growth rate and in response to treatment with hydroxylated sterols. A high level of HMG-CoA reductase activity was observed in cells at log phase of growth which progressively decreased to reach a sustained low level at stationary phase. Similarly, membrane fluidity markedly decreased in relation to growth rate. Hydroxylated sterols such as 7 beta-hydroxycholesterol or 25-hydroxycholesterol strongly inhibited HMG-CoA reductase activity whereas a water-soluble derivative of 7 beta-hydroxycholesterol sodium 3,7-bishemisuccinate had no effect. Within the same range of concentrations 7 beta-hydroxycholesterol and 25-hydroxycholesterol strongly decreased membrane fluidity when the water-soluble derivative was ineffective. Thus, the present results provide evidence for a correlation between the two tested parameters and suggest a dependency of HMG-CoA reductase activity on cell membrane fluidity.

Tumor promoting phorbol esters are able to activate Ca2+-sensitive, phospholipid-dependent protein kinase (protein kinase C) in a reconstituted system. Indol alkaloid teleocidin, a tumor promoter, has been found to be as potent as tumor promoters from the series of phorbol esters and mezerein in activating the mouse brain enzyme. Chemically unrelated tumor promoters such as tetrachlorodibenzo-p-dioxin, anthralin and phenobarbital are devoid of effect. Diacylglycerol 1,2 diolein strongly activated the enzyme whereas 1,3 diolein like 1,2 distearin were poor activators and 1,3 distearin was inactive. Although tumor-promoter-or diacylglycerol-mediated activation of protein kinase C was observed in the presence of 0.5mM EGTA, the reaction requires traces of Ca2+. Tumor promoters did not prevent inhibitory action of antipsychotic phenothiazines and local anesthetics but appear to increase IC50 of these drugs.

Glycogen accumulation in growing cultures of ZHC cells (originally derived from the Zajdela ascitic hepatoma) is accompanied by an increase in glycogen synthetase (E.C. 2.4.1.11) and phosphorylase (E.C. 2.4.1.1) activities. Essentially the synthetase b and the phosphorylase a are involved in this process. The glycogen accumulation in ZHC cells us preceeded by a noticeable peak of cAMP, whereas cGMP rises early after replating and then decreases simultaneously with the growth rate. The present results suggest that these cultured hepatoma cells undergo throughout every passage an induction process involved in glycogen synthesis storage. Since the original ascites cells growing in vivo (which lack glycogen) and the cultured ZHC cells exhibit similar glycogen synthetase and phosphorylase activities, the resurgence of the glycogenic function (Staedel and Beck, 1978) in the in vitro cultureed cells does not seem related to a change in these two enzymes. By contrast, the high cyclic nucleotide levels in the cultured cells, as compared to those in the ascites cells, offer a possible explanation.