The stromal immunoexpression of CLIC4 may be related to the difference in the biological behavior between oral squamous cell carcinoma and oral verrucous carcinoma.

BACKGROUND: Oral squamous cell carcinoma (OSCC) has high morbidity and mortality rates while oral verrucous carcinoma (OVC), an uncommon variant of OSCC, exhibits a distinct biological behavior. CLIC4 protein plays a role in the cell cycle and apoptosis regulation and participates in the myofibroblasts transdifferentiation process, which are the main cells of the tumor stroma. This study analyzed the immunoexpression of CLIC4 and α-SMA in 20 OSCC cases and 15 OVC cases. MATERIAL AND METHODS: A semiquantitative analysis of CLIC4 and α-SMA immunoexpression was performed in the parenchyma and stroma. Nuclear and cytoplasmic reactivity was analyzed separately for the CLIC4 immunostaining. The data were submitted to Pearson's chi-square and Spearman's correlation tests (p ≤ 0.05). RESULTS: In the CLIC4 analysis, there was a significant difference in the immunoexpression of this protein between OSCC and OVC stroma (p < 0.001). It was observed a higher expression of α-SMA in the OSCC stroma. There was a positive and significant correlation between CLIC4 and α-SMA immunoexpression in the OVC stroma (r = 0,612; p = 0,015). CONCLUSIONS: The decrease or absence of nuclear CLIC4 immunoexpression in the neoplastic epithelial cells and the increase of its expression in the stroma may influence the difference in biological behavior between OSCC and OVC.

Prognostic and clinicopathological significance of tumor-stroma ratio in head and neck squamous cell carcinoma: A systematic review.

BACKGROUND: Analysis of the tumor microenvironment has been proposed as a strategy for the treatment and prognosis of different neoplastic processes. A grading system based on the tumor-stroma ratio (TSR), which evaluates the proportion of stroma in relation to neoplastic parenchyma at the invasion front, has shown a strong prognostic value in different neoplastic processes. The aim of the present systematic review was to understand the role of the TSR in head and neck squamous cell carcinoma (HNSCC), evaluating its correlation with clinical and prognostic parameters. MATERIAL AND METHODS: An electronic search was performed in PubMed/Medline, Web of Science, Science Direct, Scopus, Embase, and the Cochrane Collaboration Library. Publications assessing the relationship between TSR and prognosis in cases of HNSCC were eligible. The quality of the studies was assessed independently by four evaluators using the Newcastle-Ottawa scale. RESULTS: After application of the previously es+lished inclusion/exclusion criteria, nine articles were included in the qualitative synthesis. With regards to quality on the Newcastle-Ottawa scale, an overall value of 4.55 was obtained. This systematic review demonstrated a strong association between TSR and prognosis in esophageal and oral squamous cell carcinomas. CONCLUSIONS: Histopathological analysis of the TSR can optimize the analysis of the prognosis of cases diagnosed with HNSSC. In addition, the TSR is a reliable and simple parameter that can be evaluated in hematoxylin/eosin-stained slides during routine laboratory examinations, showing high inter- and intraobserver agreement.

First record of non-native hybrid catfish Pseudoplatystoma reticulatum × Leiarius marmoratus in the Upper Paraná River basin, Brazil.

The aim of this study is to report the presence of a three non-native hybrid long-whiskered catfishes (family Pimelodidae) in the Upper Paraná River basin, Brazil. Genetic analyses demonstrated that the three presumptive hybrids were a result of the crossbreeding of Pseudoplatystoma reticulatum (central Amazonas River basin and Lower Paraná River) and Leiarius marmoratus (Amazonas, Essequibo and Orinoco rivers), producing a hybrid commonly known in Brazil as cachandiá. The potential threat to biodiversity, due to possible genetic contamination, competition and predation of wild stocks, of such artificially produced hybrid fishes is discussed.

Fatty acid cycling mechanism and mitochondrial uncoupling proteins.

We hypothesize that fatty acid-induced uncoupling serves in bioenergetic systems to set the optimum efficiency and tune the degree of coupling of oxidative phosphorylation. Uncoupling results from fatty acid cycling, enabled by several phylogenetically specialized proteins and, to a lesser extent, by other mitochondrial carriers. It is suggested that the regulated uncoupling in mammalian mitochondria is provided by uncoupling proteins UCP-1, UCP-2 and UCP-3, whereas in plant mitochondria by PUMP and StUCP, all belonging to the gene family of mitochondrial carriers. UCP-1, and hypothetically UCP-3, serve mostly to provide nonshivering thermogenesis in brown adipose tissue and skeletal muscle, respectively. Fatty acid cycling was documented for UCP-1, PUMP and ADP/ATP carrier, and is predicted also for UCP-2 and UCP-3. UCP-1 mediates a purine nucleotide-sensitive uniport of monovalent unipolar anions, including anionic fatty acids. The return of protonated fatty acid leads to H+ uniport and uncoupling. UCP-2 is probably involved in the regulation of body weight and energy balance, in fever, and defense against generation of reactive oxygen species. PUMP has been discovered in potato tubers and immunologically detected in fruits and corn, whereas StUCP has been cloned and sequenced froma a potato gene library. PUMP is supposed to act in the termination of synthetic processes in mature fruits and during the climacteric respiratory rise.

Canine visceral leishmaniasis in São José de Ribamar, Maranhão State, Brazil.

Here, we describe the situation of canine visceral leishmaniasis in two villages of São José de Ribamar in Maranhão State/Brazil, where human cases have been registered. Blood samples of 36 household crossbred dogs from Sergio Tamer village and 43 dogs from Quinta village were collected and the serum used for serological diagnosis. An Indirect Fluorescent Antibody Test (IFAT) and enzyme-linked immunosorbent assay (ELISA) were used to detect antibodies against Leishmania. The clinical examination showed that 25% of the canine population of Quinta presented a poor body condition and in 39%, ectoparasites (ticks and fleas) were detected. In both tests, serology revealed that 21% (9 out of 43) of the dogs presented antibodies against Leishmania (55% were asymptomatic and 45% were symptomatic). In the Vila Sérgio Tamer, 25% (9 out of 36) of the dogs were seropositive for Leishmania (66.67% were asymptomatic and 33.33% were symptomatic), 33% presented poor body condition, and 22% have ectoparasites. The clinical signs more frequent were skin lesions. The statistical analysis showed that there was no statistical difference (p>0.05) between the seropositivity of the dogs from the two villages. The same was observed when the clinical signs were compared (p>0.05). Both villages have favorable conditions to maintain the cycle of leishmaniasis.

Activation of the potato plant uncoupling mitochondrial protein inhibits reactive oxygen species generation by the respiratory chain.

A variety of plant tissues contain an uncoupling mitochondrial protein (PUMP), recently described and characterized by our group. In this study we show that the inhibition of PUMP activity in potato tuber mitochondria significantly increases mitochondrial H2O2 generation, while PUMP substrates, such as linoleic acid, reduce mitochondrial H2O2 generation. This H2O2 generation occurred mainly by the dismutation of superoxide radicals formed through monoelectronic reduction of O2 by semiquinone forms of coenzyme Q. The results presented suggest that protection against mitochondrial oxidative stress may be a physiological role of PUMP.

Functional reconstitution of Arabidopsis thaliana plant uncoupling mitochondrial protein (AtPUMP1) expressed in Escherichia coli.

The Arabidopsis thaliana uncoupling protein (UCP) gene was expressed in Escherichia coli and isolated protein reconstituted into liposomes. Linoleic acid-induced H+ fluxes were sensitive to purine nucleotide inhibition with an apparent K(i) (in mM) of 0.8 (GDP), 0.85 (ATP), 0.98 (GTP), and 1.41 (ADP); the inhibition was pH-dependent. Kinetics of AtPUMP1-mediated H+ fluxes were determined for lauric, myristic, palmitic, oleic, linoleic, and linolenic acids. Properties of recombinant AtPUMP1 indicate that it represents a plant counterpart of animal UCP2 or UCP3. This work brings the functional and genetic approaches together for the first time, providing strong support that AtPUMP1 is truly an UCP.

Possible basic and specific functions of plant uncoupling proteins (pUCP).

Evidence has been provided that the plant uncoupling proteins (pUCP) play basic physiological roles similar to the other uncoupling protein subfamily members (mammalian UCP1,2,3,4 and BMCP) and are effective in the situations of slight uncoupling that leads to: (1) accelerated respiration and metabolic rates that are beneficial to plant growth and development; (2) decreased formation of reactive oxygen species in mitochondria; and, (3) mild thermogenesis, inevitably accompanying the previous two phenomena. Hypothetically, specific physiological roles of pUCP such as cut off of ATP synthesis could be manifested in connection with climacteric respiratory rise during fruit ripening, seed dormancy, and plant senescence. pUCP might also facilitate growth under low temperatures, e.g., during seed germination or in roots. The existence of these specific roles is suggested by the immunochemical and functional localization of pUCP in mitochondria of fruits, seeds and roots of various plant species.

Important amino acid residues of potato plant uncoupling protein (StUCP).

Chemical modifications were used to identify some of the functionally important amino acid residues of the potato plant uncoupling protein (StUCP). The proton-dependent swelling of potato mitochondria in K(+)-acetate in the presence of linoleic acid and valinomycin was inhibited by mersalyl (K(i) = 5 microM) and other hydrophilic SH reagents such as Thiolyte MB, iodoacetate and 5, 5'-dithio-bis-(2-nitrobenzoate), but not by hydrophobic N-ethylmaleimide. This pattern of inhibition by SH reagents was similar to that of brown adipose tissue uncoupling protein (UCP1). As with UCP1, the arginine reagent 2,3-butadione, but not N-ethylmaleimide or other hydrophobic SH reagents, prevented the inhibition of StUCP-mediated transport by ATP in isolated potato mitochondria or with reconstituted StUCP. The results indicate that the most reactive amino acid residues in UCP1 and StUCP are similar, with the exception of N-ethylmaleimide-reactive cysteines in the purine nucleotide-binding site.

[Characteristics of the demand for cranial computerized tomography: reasons and costs of the exam]. / Características da demanda por tomografia computadorizada crânio-encefálica. Motivos e custos dos exames.

It was reviewed a series of 2860 cerebral computed tomography (CCT) in order to compare the main reasons at referral to investigation with the CCT results and the costs with normal and abnormal CCT. It was also studied the age and sex of the patients. Data were collected from one out of three diagnostic centers in Salvador, Brasil, for a three years period. The 2860 CCT exclude all investigation carried out for the follow-up of a previously diagnosed abnormality. CCT abnormalities were detected in 1152 (40.3%). The following reasons showed the highest proportion of abnormal CCT, for males and females respectively: demential syndrome (91.7 and 83.3%); cerebrovascular accidents (85.1 and 73.6%); infectious and parasitary diseases (76.5 and 78.6%); tumors (65.8 and 55.4%); and head injuries, 63.6% for males. In the female group, 65.0% of the CCT were normal, in a range of 65.0 to 80.0% for the age groups under 54 years old. In the male group, the highest proportion of normal CCT was found in the age groups: 25-34 (68.4%), < 15 (62.9%) and 35-44 (62.7%). The most common reasons for normal CCT for males and females were: headache (81.3 and 87.5%); dizziness/vertigo (79.3 and 78.6%); seizures (67.3 and 70.0%); psychomotor deficiency (72.0 and 67.7%) and "endocrine disorders", 75.0% for each sex. The highest proportion of normal CCT (65.3%) was requested by medical "convenios". The cost with normal CCT reached US$565,225 and with the abnormal ones, US$381,247. Costs with normal CCT were 2.2 higher for medical "convenios" as compared to those of the National Institute of Security requests and 2.8 more than those of private medicine.

Are age and ethics related?

Ethical values of 171 college students at California State University, Chico, were measured, using a subset of the Rokeach (1968, 1971) Value Survey. Nonparametric statistical analysis, four value measures, and four different consistent tests of significance and probability showed, surprisingly, that the younger students were more ethical than the older students. College students under 21 scored significantly higher ethically on three out of the four measures. Younger college students valued equality, freedom, and honesty more than their older classmates did. Surprisingly also, the younger students were significantly more concerned with being helpful and intellectual and were less involved in pursuing an exciting life and in social recognition than were the older students.

Evidence for anion-translocating plant uncoupling mitochondrial protein in potato mitochondria.

Transport properties of plant mitochondria from potato tubers were investigated using the swelling technique and membrane potential measurements. Proton-dependent swelling of fatty acid-depleted mitochondria in potassium acetate with valinomycin was possible only in the presence of fatty acids (linoleic acid and 12-(4-azido-2-nitrophenylamino)dodecanoic acid) and was inhibited by various purine nucleotides including ATP, GDP, and GTP. Swelling representing uptake of hexanesulfonate was also inhibited by purine nucleotides. Also, the membrane potential of fatty acid-depleted potato mitochondria energized by succinate declined upon the addition of linoleic acid or 12-(4-azido-2-nitrophenylamino)dodecanoic acid, and this decrease was prevented by ATP and other purine nucleotides. These transport activities are identical to those reported for brown adipose tissue mitochondria and related to the uncoupling protein; therefore, we ascribed them to the plant mitochondrial uncoupling protein (PUMP). A major difference between plant and mammalian uncoupling protein is that PUMP transports small hydrophilic anions such as Cl- very slowly, if at all. We suggest that PUMP may play an important role in plant physiology, where a regulated uncoupling and thermogenesis can proceed during fruit and seed development.

Reconstituted plant uncoupling mitochondrial protein allows for proton translocation via fatty acid cycling mechanism.

Potato and tomato plant uncoupling mitochondrial protein (PUMP) was reconstituted into liposomes, and K+ or H+ fluxes associated with fatty acid (FA)-induced ion movement were measured using fluorescent ion indicators potassium binding benzofuraneisophthalate and 6-methoxy-N-(3-sulfopropyl)-quinolinium. We suggest that PUMP, like its mammalian counterpart, the uncoupling protein of brown adipose tissue mitochondria (Garlid, K. D., Orosz, D. E., Modrianský, M., Vassanelli, S., and Jeek, P. (1996), J. Biol. Chem. 271, 2615-2702), allows for H+ translocation via a FA cycling mechanism. Reconstituted PUMP translocated anionic linoleic and heptylbenzoic acids, undecanesulfonate, and hexanesulfonate, but not phenylvaleric and abscisic acids or Cl-. Transport was inhibited by ATP and GDP. Internal acidification of protein-free liposomes by linoleic or heptylbenzoic acid indicated that H+ translocation occurs by FA flip-flopping across the lipid bilayer. However, addition of valinomycin after FA-initiated GDP-sensitive H+ efflux solely in proteoliposomes, indicating that influx of anionic FA via PUMP precedes a return of protonated FA carrying H+. Phenylvaleric acid, unable to flip-flop, was without effect. Kinetics of FA and undecanesulfonate uniport suggested the existence of an internal anion binding site. Exponential flux-voltage characteristics were also studied. We suggest that regulated uncoupling in plant mitochondria may be important during fruit ripening, senescence, and seed dormancy.

Plant uncoupling mitochondrial protein activity in mitochondria isolated from tomatoes at different stages of ripening.

In the present study we have observed a higher state of coupling in respiring mitochondria isolated from green as compared to red tomatoes (Lycopersicon esculentum, Mill.). Green tomato mitochondria produced a membrane potential (deltapsi) high enough to phosphorylate ADP, whereas in red tomato mitochondria, BSA and ATP were required to restore deltapsi to the level of that obtained with green tomato mitochondria. This supports the notion that such uncoupling in red tomato mitochondria is mediated by a plant uncoupling mitochondrial protein (PUMP; cf. Vercesi et al., 1995). Nevertheless, mitochondria from both green and red tomatoes exhibited an ATP-sensitive linoleic acid (LA)-induced deltapsi decrease providing evidence that PUMP is also present in green tomatoes. Indeed, proteoliposomes containing reconstituted green or red tomato PUMP showed LA uniport and LA-induced H+ transport. It is suggested that the higher concentration of free fatty acids (PUMP substrates) in red tomatoes could explain the lower coupling state in mitochondria isolated from these fruits.

Ca2+-independent permeabilization of the inner mitochondrial membrane by peroxynitrite is mediated by membrane protein thiol cross-linking and lipid peroxidation.

Peroxynitrite anion, the reaction product of superoxide and nitric oxide, is a potent biological oxidant, which inactivates mammalian heart mitochondrial NADH-coenzyme Q reductase (complex I), succinate dehydrogenase (complex II), and ATPase, without affecting cytochrome c oxidase (complex IV). In this paper, we evaluated the effect of peroxynitrite on mitochondrial membrane integrity and permeability under low calcium concentration. Phosphate buffer was used in most of our experiments since Hepes, Tris, mannitol, and sucrose were found to inhibit the oxidative chemistry of peroxynitrite. Peroxynitrite (0.1-1.0 mM) caused a dose-dependent decrease in the ability of mitochondria to build up a membrane potential when N,N,N',N'-tetramethyl-p-phenylenediamine/ascorbate were used as substrate. Elimination of the membrane potential was accompanied by penetration of the osmotic support (KCl/NaCl) into the matrix as judged by the parallel occurrence of mitochondrial swelling. This swelling was partially inhibited by dithiothreitol (DTT) or butylated hydroxytoluene (BHT) and was insensitive to ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, ADP, and cyclosporin A. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of solubilized membrane proteins indicated that alterations in membrane permeability were associated with the production of protein aggregates due to membrane protein thiol cross-linking. The protective effect of DTT on both mitochondrial swelling and protein polymerization suggests the involvement of disulfide bonds in the membrane permeabilization process. In addition, the increase in thiobarbituric acid-reactive substances and the partial inhibitory effect of BHT indicate the occurrence of lipid peroxidation. These results support the idea that under our experimental conditions peroxynitrite causes mitochondrial structural and functional alterations by Ca2+-independent mechanisms through lipid peroxidation and protein sulfhydryl oxidation.

No relationship between proliferative activity and the MACIS prognostic scoring system in papillary thyroid carcinoma.

BACKGROUND: The MACIS score uses metastasis, age, completeness of resection, local invasion, and tumor size to stratify patients with papillary thyroid carcinoma (PTC) into four groups with different survival. METHODS: Immunostaining for proliferating cell nuclear antigen (PCNA) was done in 43 cases of PTC. Relationships between proliferative index (percentage of cells that were PCNA positive) and the MACIS parameters were examined. Double staining for PCNA and for silver-stained nucleolar organizer regions (AgNORs, indicating proliferation) was performed in 10 cases. RESULTS: PCNA was detected only in tumor cells. The proliferative index was low (mean, 14.2%; median, 13.0%), did not differ between MACIS groups (p = 0.56), and showed no association with individual MACIS parameters. PCNA immunostaining correlated with AgNOR staining. The mean AgNOR count was 2.28 in PCNA-positive cells and 1.85 in PCNA-negative cells (p

Important amino acid residues of potato plant uncoupling protein (StUCP)

Chemical modifications were used to identify some of the functionally important amino acid residues of the potato plant uncoupling protein (StUCP). The proton-dependent swelling of potato mitochondria in K+-acetate in the presence of linoleic acid and valinomycin was inhibited by mersalyl (Ki = 5 æM) and other hydrophilic SH reagents such as Thiolyte MB, iodoacetate and 5,5'-dithio-bis-(2-nitrobenzoate), but not by hydrophobic N-ethylmaleimide. This pattern of inhibition by SH reagents was similar to that of brown adipose tissue uncoupling protein (UCP1). As with UCP1, the arginine reagent 2,3-butadione, but not N-ethylmaleimide or other hydrophobic SH reagents, prevented the inhibition of StUCP-mediated transport by ATP in isolated potato mitochondria or with reconstituted StUCP. The results indicate that the most reactive amino acid residues in UCP1 and StUCP are similar, with the exception of N-ethylmaleimide-reactive cysteines in the purine nucleotide-binding site