Exogenous application of salicylic acid induces salinity tolerance in eggplant seedlings

Abstract Under salt stress conditions, plant growth is reduced due to osmotic, nutritional and oxidative imbalance. However, salicylic acid acts in the mitigation of this abiotic stress by promoting an increase in growth, photosynthesis, nitrogen metabolism, synthesis of osmoregulators and antioxidant enzymes. In this context, the objective was to evaluate the effect of salicylic acid doses on the growth and physiological changes of eggplant seedlings under salt stress. The experiment was conducted in a greenhouse, where the treatments were distributed in randomized blocks using a central composite matrix Box with five levels of electrical conductivity of irrigation water (CEw) (0.50; 1.08; 2.50; 3.92 and 4.50 dS m-1), associated with five doses of salicylic acid (SA) (0.00; 0.22; 0.75; 1.28 and 1.50 mM), with four repetitions and each plot composed of three plants. At 40 days after sowing, plant height, stem diameter, number of leaves, leaf area, electrolyte leakage, relative water content, and total dry mass were determined. ECw and SA application influenced the growth and physiological changes of eggplant seedlings. Increasing the ECw reduced growth in the absence of SA. Membrane damage with the use of SA remained stable up to 3.9 dS m-1 of ECw. The relative water content independent of the CEw increased with 1.0 mM of SA. The use of SA at the concentration of 1.0 mM mitigated the deleterious effect of salinity on seedling growth up to 2.50 dS m-1 of ECw.

Resumo Em condições de estresse salino, o crescimento das plantas é reduzido, em virtude, do desequilíbrio osmótico, nutricional e oxidativo. Contudo, o ácido salicílico atua na mitigação desse estresse abiótico por promover incremento no crescimento, fotossíntese, metabolismo do nitrogênio, síntese de osmorreguladores e enzimas antioxidantes. Nesse contexto, objetivou-se avaliar o efeito de doses de ácido salicílico sobre o crescimento e alterações fisiológicas de mudas de berinjela sob estresse salino. O experimento foi conduzido em casa de vegetação, onde os tratamentos foram distribuídos em blocos ao acaso utilizando uma matriz composta central Box com cinco níveis de condutividade elétrica da água de irrigação (CEa) (0,50; 1,08; 2,50; 3,92 e 4,50 dS m-1), associada a cinco doses de ácido salicílico (AS) (0,00; 0,22; 0,75; 1,28 e 1,50 mM), com quatro repetições e cada parcela composta por três plantas. Aos 40 dias após a semeadura, foram determinados a altura da planta, diâmetro do caule, número de folhas, área foliar, vazamento de eletrólito, teor relativo de água e massa seca total. A CEa e a aplicação de AS influenciaram no crescimento e nas alterações fisiológicas das mudas de berinjela. O aumento da CEa reduziu o crescimento na ausência de AS. O dano de membrana com o uso de AS manteve-se estável até 3,9 dS m-1 de CEa. O conteúdo relativo de água independentemente da CEa aumentou com 1 mM de SA. O uso de AS na concentração de 1 mM mitigou o efeito deletério da salinidade no crescimento das mudas até 2,50 dS m-1 de CEa.

Exogenous application of salicylic acid induces salinity tolerance in eggplant seedlings / Aplicação exógena de ácido salicílico induz tolerância à salinidade em mudas de berinjela

Abstract Under salt stress conditions, plant growth is reduced due to osmotic, nutritional and oxidative imbalance. However, salicylic acid acts in the mitigation of this abiotic stress by promoting an increase in growth, photosynthesis, nitrogen metabolism, synthesis of osmoregulators and antioxidant enzymes. In this context, the objective was to evaluate the effect of salicylic acid doses on the growth and physiological changes of eggplant seedlings under salt stress. The experiment was conducted in a greenhouse, where the treatments were distributed in randomized blocks using a central composite matrix Box with five levels of electrical conductivity of irrigation water (CEw) (0.50; 1.08; 2.50; 3.92 and 4.50 dS m-1), associated with five doses of salicylic acid (SA) (0.00; 0.22; 0.75; 1.28 and 1.50 mM), with four repetitions and each plot composed of three plants. At 40 days after sowing, plant height, stem diameter, number of leaves, leaf area, electrolyte leakage, relative water content, and total dry mass were determined. ECw and SA application influenced the growth and physiological changes of eggplant seedlings. Increasing the ECw reduced growth in the absence of SA. Membrane damage with the use of SA remained stable up to 3.9 dS m-1 of ECw. The relative water content independent of the CEw increased with 1.0 mM of SA. The use of SA at the concentration of 1.0 mM mitigated the deleterious effect of salinity on seedling growth up to 2.50 dS m-1 of ECw.

Resumo Em condições de estresse salino, o crescimento das plantas é reduzido, em virtude, do desequilíbrio osmótico, nutricional e oxidativo. Contudo, o ácido salicílico atua na mitigação desse estresse abiótico por promover incremento no crescimento, fotossíntese, metabolismo do nitrogênio, síntese de osmorreguladores e enzimas antioxidantes. Nesse contexto, objetivou-se avaliar o efeito de doses de ácido salicílico sobre o crescimento e alterações fisiológicas de mudas de berinjela sob estresse salino. O experimento foi conduzido em casa de vegetação, onde os tratamentos foram distribuídos em blocos ao acaso utilizando uma matriz composta central Box com cinco níveis de condutividade elétrica da água de irrigação (CEa) (0,50; 1,08; 2,50; 3,92 e 4,50 dS m-1), associada a cinco doses de ácido salicílico (AS) (0,00; 0,22; 0,75; 1,28 e 1,50 mM), com quatro repetições e cada parcela composta por três plantas. Aos 40 dias após a semeadura, foram determinados a altura da planta, diâmetro do caule, número de folhas, área foliar, vazamento de eletrólito, teor relativo de água e massa seca total. A CEa e a aplicação de AS influenciaram no crescimento e nas alterações fisiológicas das mudas de berinjela. O aumento da CEa reduziu o crescimento na ausência de AS. O dano de membrana com o uso de AS manteve-se estável até 3,9 dS m-1 de CEa. O conteúdo relativo de água independentemente da CEa aumentou com 1 mM de SA. O uso de AS na concentração de 1 mM mitigou o efeito deletério da salinidade no crescimento das mudas até 2,50 dS m-1 de CEa.

Filter cake increases sugarcane yield.

Sugarcane cultivation stands out in Brazilian agribusiness, covering more than eight million hectares for the production of sugar, ethanol, and by-products. Fertilization is one of the limiting factors in sugarcane yield, for which filter cake is a viable solution to meet plant nutritional needs. This study aimed to assess the effect of enriched filter cake on gas exchange and yield in RB041443 sugarcane, cultivated in soils of the coastal tablelands of Paraíba, Brazil. The experiment was conducted in the Monte Alegre S/A sugarcane mill, in the municipality of Mamanguape, using a randomized blocks experimental design, with 12 treatments (T1- cake, T2- cake + MAP, T3- cake + gypsum, T4 - cake + phosphate, T5- cake + bagasse, T6- cake + MAP + gypsum, T7- cake + MAP + phosphate, T8- cake + MAP + bagasse, T9- cake + gypsum + phosphate, T10- cake + gypsum + bagasse, T11- cake + phosphate + bagasse, and T12- control (only MAP)), and 4 replications, totaling 48 plots. A significant effect (5% probability) was also observed for the variables number of leaves and tons of stem per hectare (TSH). T1- cake, T4- cake + phosphate, T6- cake + MAP + gypsum and T10- cake + gypsum + bagasse, had the best results for TSH, with yields greater than 140 t ha-1. Regarding stomatal conductance, the highest values were obtained in T6 and T8, which, together with T11, had the highest gs values. Concerning the internal carbon concentration, T1, T2, T6, and T8 stood out. T6 also had a significant effect on transpiration. From this study, it was concluded that the use of enriched filter cake as a base fertilizer in sugarcane culture contributes to increasing the yield of the RB041443 variety, generating positive responses for plant gas exchange, being T1 and T10 indicated to increase the production in the sugar-energy sector.

Exogenous application of salicylic acid induces salinity tolerance in eggplant seedlings.

Under salt stress conditions, plant growth is reduced due to osmotic, nutritional and oxidative imbalance. However, salicylic acid acts in the mitigation of this abiotic stress by promoting an increase in growth, photosynthesis, nitrogen metabolism, synthesis of osmoregulators and antioxidant enzymes. In this context, the objective was to evaluate the effect of salicylic acid doses on the growth and physiological changes of eggplant seedlings under salt stress. The experiment was conducted in a greenhouse, where the treatments were distributed in randomized blocks using a central composite matrix Box with five levels of electrical conductivity of irrigation water (CEw) (0.50; 1.08; 2.50; 3.92 and 4.50 dS m-1), associated with five doses of salicylic acid (SA) (0.00; 0.22; 0.75; 1.28 and 1.50 mM), with four repetitions and each plot composed of three plants. At 40 days after sowing, plant height, stem diameter, number of leaves, leaf area, electrolyte leakage, relative water content, and total dry mass were determined. ECw and SA application influenced the growth and physiological changes of eggplant seedlings. Increasing the ECw reduced growth in the absence of SA. Membrane damage with the use of SA remained stable up to 3.9 dS m-1 of ECw. The relative water content independent of the CEw increased with 1.0 mM of SA. The use of SA at the concentration of 1.0 mM mitigated the deleterious effect of salinity on seedling growth up to 2.50 dS m-1 of ECw.

Anatomical description of the skulls of peccaries (Tayassu tajacu, Linnaeus 1758) by computed tomography / [Descrição anatômica de crânio de catetos (Tayassu tajacu, Linnaeus, 1758) por tomografia computadorizada]

The aim of this study was to evaluate the anatomical structures of the skulls of peccaries to establish the basis for their clinical study and future preclinical research. Ten skulls of adult peccaries were subjected to tomographic examination. The data obtained were processed via three-dimensional image reconstruction software (3D images). The reconstructions obtained from the neurocranium of the studied specimens allowed the identification and description of the following structures: nasal bone, frontal bone, parietal bones, incisor bone, maxillary bone, zygomatic bone, temporal bone, palatal bone, occipital bone, vomer bone, pterygoid bone, sphenoid bone, paranasal sinuses and orbit. Computed tomography proved to be an important diagnostic tool in the investigation of the skull of this species, allowing the acquisition of anatomical values not yet documented for the species in the literature.(AU)

O objetivo deste estudo foi avaliar as estruturas anatômicas dos crânios de catetos, a fim de se estabelecerem as bases para seu estudo clínico e futuras pesquisas pré-clínicas. Dez crânios de catetos adultos foram submetidos a exame tomográfico. Os dados obtidos foram introduzidos em um software de reconstrução de imagens tridimensionais (imagens em 3D). As reconstruções obtidas do neurocrânio dos espécimes estudados permitiram a identificação e a descrição das seguintes estruturas: osso nasal, osso frontal, ossos parietais, osso incisivo, osso maxilar, osso zigomático, osso temporal, osso palatino, osso occipital, osso vômer, osso pterigoide, osso esfenoide, seios paranasais e órbita. A tomografia computadorizada mostrou-se como uma ferramenta diagnóstica importante na investigação do crânio dessa espécie, permitindo a aquisição de valores anatômicos ainda não documentados para a espécie na literatura.(AU)

B-mode and Doppler ultrasonography of abdominal structures of the peccary (Tayassu tajacu, Linnaeus 1758) / [Ultrassonografias Doppler e modo-B das estruturas abdominais de catetos (Tayassu tajacu Linnaeus, 1758)]

This study used B-mode and Doppler ultrasonography to characterize the abdominal structures of healthy peccaries raised in captivity. Fifteen peccaries were used for this study. The urinary vesicle appeared as an ovoid structure, located in the abdominal and pelvic transition, with a hyperechogenic, thin, smooth, and regular wall. The kidneys presented retroperitoneal topography and had similar sizes. The kidney/aorta ratio had an average value of 10.53±15cm (right) and 10.23±0.12 (left). The right adrenal gland had a length of 1.93±0.34cm and diameter of 0.56±0.16cm. The left adrenal gland had a length of 1.85±0.42cm and diameter of 0.52±0.11cm. The spleen had a diameter of 1.13±0.18cm. The hepatic vein demonstrated polyphasic flow in pulsed Doppler, with two retrograde peaks and an anterograde peak with a flow velocity of 25.7±0.83cm/s. The abdominal aorta had a diameter of 0.58±0.05cm and a flow velocity of 115.17±5.32cm/s. The morphological and hemodynamic study of the abdominal structures of the peccary, observed through B-mode and Doppler ultrasonography, aided in identifying the size, shape, position, echogenicity, and echotexture of the abdominal organs and in making inferences about the normal parameters for these structures in this species.(AU)

Este estudo teve como objetivo utilizar as ultrassonografias de modo-B e Doppler para caracterizar as estruturas abdominais de um cateto sadio criado em cativeiro. Quinze catetos foram utilizados para este estudo. A vesícula urinária apareceu como uma estrutura ovoide, localizada na transição entre as partes abdominal e pélvica, com uma parede hiperecogênica, fina, lisa e regular. Os rins apresentaram topografia retroperitoneal e tamanhos semelhantes. A relação rim/aorta teve um valor médio de 10,53 ± 15cm (direita) e 10,23 ± 0,12cm (esquerda). A glândula adrenal direita tinha um comprimento de 1,93 ± 0,34cm e um diâmetro de 0,56 ± 0,16cm. A glândula suprarrenal esquerda tinha um comprimento de 1,85 ± 0,42cm e um diâmetro de 0,52 ± 0,11cm. O baço tinha um diâmetro de 1,13 ± 0,18cm. A veia hepática demonstrou fluxo polifásico no Doppler pulsátil, com dois picos retrógrados e um pico anterógrado com velocidade de fluxo de 25,7±0,83cm/s. A aorta abdominal tinha um diâmetro de 0,58 ± 0,05cm e uma velocidade de fluxo de 115,17±5,32cm/s. Os estudos morfológico e hemodinâmico das estruturas abdominais do queixada, observadas por meio das ultrassonografias modo-B e Doppler, auxiliaram na identificação do tamanho, da forma, da posição, da ecogenicidade e da ecotextura dos órgãos abdominais e na realização de inferências sobre os parâmetros de normalidade para as estruturas nas espécies.(AU)

Echocardiographic reference ranges for sedated healthy peccaries ( Tayassu tajacu, Linnaeus, 1758 ) / Valores de referência para catetos saudáveis sedados

Peccaries are wild mammals belonging to the Tayassu genus that are found almost everywhere in the Americas and have demonstrated great potential as an experimental model for scientific investigations. Twelve healthy adult animals were sedated to perform echocardiographic examinations in B, M and Doppler mode. The variables that exhibited statistically significant correlation coefficients with weight were LVFWd, LVIDd, LVIDs, E wave, A'RV, MAM, and TAPSE. The HR exhibited a negative relationship with the IVRT. The LA variable showed a positive correlation with the AO. The MAM exhibited correlations with the LVIDd and LVIDs. The TAPSE showed positive correlations with the E'RV and A'RV. The present study provides the first reference values for echocardiographic measurements in B, M and Doppler modes from peccaries anesthetized with ketamine and midazolam. Echocardiography was easy to perform in collared peccaries, and the collected data revealed values that can aid in their clinical management and conservation.(AU)

Catetos são mamíferos selvagens, pertencentes ao gênero Tayassu, encontrados em quase toda a América, os quais têm se destacado como modelos experimentais. Doze animais adultos saudáveis foram sedados para a realização de exames ecocardiográficos em modos B, M e Doppler. As variáveis que apresentaram coeficientes de correlação estatisticamente significativos em relação ao peso foram: LVFWd, LVIDd, LVIDs, onda E, A'RV, MAM, TAPSE. O HR mostrou correlação positiva com LA/AO, onda E, onda A, MAM, TAPSE e E/IVRT, e negativa com IVRT. Os valores de AVmax mostraram correlações positivas com onda E e onda A'. A variável LA mostrou correlação positiva com AO e correlação negativa com IVSd. A EF apresentou forte correlação com a relação de ondas FS, E/A, com A', E'RV. FS apresentou correlação positiva com a relação de onda E/A. O MAM mostrou correlação com LVIDd e LVIDs. TAPSE mostrou correlações positivas com E'RV e A'RV. O presente estudo forneceu os primeiros valores de referência para medições ecocardiográficas em modos B, M e Doppler de catetos anestesiados com ketamina e midazolam. O exame ecocardiográfico em catetos foi de fácil execução e os dados encontrados evidenciaram valores que podem auxiliar no seu manejo clínico e conservação.(AU)

Organogenesis and foetal haemodynamics during the normal gestation of healthy black-rumped agoutis (Dasyprocta prymnolopha, Wagler, 1831) bred in captivity.

The objective of this study was to define the patterns of organogenesis and foetal haemodynamics during the normal gestation of healthy agoutis (Dasyprocta prymnolopha) kept in captivity. Thirty pregnant agoutis that ranged in size from small to medium and weighed between 2.5 and 3 kg underwent B-mode and Doppler ultrasonography for the biometric evaluation of the foetal organs. The foetal aortic blood flow proved to be predominantly systolic, and the measured flow velocity was 78.89 ± 2.95 cm/s, with a maximum pressure gradient of 2.12 ± 0.27 mmHg. The liver was characterized by its large volume, occupying the entire cranial aspect of the abdominal cavity, and it was associated cranially with the diaphragm and caudally with the stomach. The flow velocity in the portal vein was estimated to equal 12.17 ± 2.37 cm/s, with a resistivity index of 0.82 ± 0.05. The gallbladder was centrally located and protruded cranially towards the diaphragm. The spleen was visualized as an elongated structure with tapered cranial and caudal extremities, and the foetal kidneys were visualized bilaterally in the retroperitoneal region, with the right kidney positioned slightly more cranially than the left. The morphological characterization and hemodynamic analysis of the foetal organs of black-rumped agoutis via B-mode and Doppler ultrasonography allow determination of the vascular network and of reference values for the blood flow required for perfusing the anatomical elements essential for maintaining the viability of foetuses at different gestational ages.

Nucleation, Growth Mechanism, and Controlled Coating of ZnO ALD onto Vertically Aligned N-Doped CNTs.

Zinc oxide thin films were deposited on vertically aligned nitrogen-doped carbon nanotubes (N-CNTs) by atomic layer deposition (ALD) from diethylzinc and water. The study demonstrates that doping CNTs with nitrogen is an effective approach for the "activation" of the CNTs surface for the ALD of metal oxides. Conformal ZnO coatings are already obtained after 50 ALD cycles, whereas at lower ALD cycles an island growth mode is observed. Moreover, the process allows for a uniform growth from the top to the bottom of the vertically aligned N-CNT arrays. X-ray photoelectron spectroscopy demonstrates that ZnO nucleation takes place at the N-containing species on the surface of the CNTs by the formation of the Zn-N bonds at the interface between the CNTs and the ZnO film.

A parallel increase in placental oxidative stress and antioxidant defenses occurs in pre-gestational type 1 but not gestational diabetes.

We aimed to determine the oxidative stress status in placentas obtained from gestational (GDM) and type 1 (T1D) diabetic pregnancies. Malonaldehyde and protein carbonyls, two biomarkers of oxidative damage, were higher in T1D but not in GDM placentas. Also, higher reduced glutathione and lower oxidized glutathione levels and higher glutathione peroxidase activity were found in T1D but not in GDM placentas. These results suggest that T1D placentas may develop a protective antioxidant mechanism to overcome higher oxidative stress levels.

Pressure-induced formation of inactive triple-shelled rotavirus particles is associated with changes in the spike protein Vp4.

Rotaviruses are non-enveloped, triple-shelled particles that cause enteritis in animals and humans. The interactions among the different viral proteins located in the three concentric layers make the rotavirus particle an excellent model for physico-chemical and biological studies of viral assemblage. SA11-4S rotaviruses subjected to high pressure were inactivated by more than five log units. After pressure treatment, the particles were recovered with slight structural changes when compared to the control. Electron microscopy suggested subtle changes in the viral outer layer in some pressurised particles. Fluorescence spectroscopy showed that much more dramatic changes were produced by urea denaturation than by pressure. Based on the fluorescence spectrum, the genome resistance to ribonuclease, and the absence of changes in hydrodynamic properties, there was little or no disruption of the capsid under pressure. On the other hand, hemagglutination assays indicated that the main component affected by pressure was the spike protein VP4, thus accounting for changes in interaction with host cells and greatly reduced infectivity. The changes leading to inactivation did not cause removal of VP4 from the outer capsid, as verified by size-exclusion chromatography. Antibodies raised against pressurised material were as effective as antibodies raised against the intact virus, based on their neutralisation titre in plaque reduction assays, enzyme-linked immunosorbent assays and direct interaction with the particle, as measured by gel-filtration chromatography. Therefore, the new conformation of the pressurised particle did not result in loss of immunogenicity. We propose that pressure alters the receptor-binding protein VP4 by triggering changes similar to those produced when the virus interacts with target cells. As the changes in VP4 conformation caused by pressure occur prior to virus exposure to target cells, it leads to non-infectious particles and may lead to the exposure of previously occult epitopes, important for vaccine development.

Calcium-induced quenching of intrinsic fluorescence in brain myosin V is linked to dissociation of calmodulin light chains.

Myosin V isolated from chick brain (BM V) is a multimeric protein of about 640 kDa consisting of two intertwined heavy chains of 212 kDa and multiple light chains of 10 to 20 kDa. A distinctive feature of the heavy chain is an extended neck region with six consensus IQ sites for the binding of calmodulin (CaM) and myosin light chains. The actin-activated MgATPase has been shown to require >/=1 microM Ca2+ for full activity, and evidence points to a myosin-linked regulatory system where the CaM light chains participate as modulators for the Ca2+ signal. Still, the precise mechanism of Ca2+ regulation remains unknown. In the present study we have used the intrinsic tryptophan fluorescence of native BM V to monitor conformational changes of BM V induced by Ca2+, and we relate these changes to CaM dissociation from the BM V molecule. The fluorescence intensity decreases approximately 17% upon addition of sub-micromolar concentrations of Ca2+ (K0.5 = 0.038 microM). This decrease in fluorescence, which is dominated by a conformational change in the heavy chain, can be reversed by addition of 1, 2-di(2-aminoethoxy)ethane-N,N,N',N'tetraacetic acid (EGTA) followed by an excess of CaM, but not by addition of EGTA alone. Gel filtration of native BM V using HPLC shows that CaM is partially dissociated from the heavy chain in EGTA and dissociates further upon addition of sub-micromolar concentrations of Ca2+. These observations suggest that the affinity of CaM for at least one of the IQ sites on the BM V heavy chain decreases with Ca2+ and that the Ca2+ concentration required for this effect is lower than that needed to activate acto-BM V. Using a cosedimentation assay in the presence of actin, we also observe partial dissociation of CaM when Ca2+ is absent, but now the addition of Ca2+ has a biphasic effect: sub-micromolar Ca2+ concentrations lead to reassociation of CaM with the heavy chain, followed by dissociation when Ca2+ exceeds 5-10 microM. Thus, the binding of CaM to BM V is affected by both actin and Ca2+.

Intermediate states of assembly in the dissociation of gastropod hemocyanin by hydrostatic pressure.

Under physiological conditions, the oxygen-transport protein from the gastropod Megalobulimulus ovatus, an extracellular hemocyanin, is composed of 20 identical subunits organized into a cylindrical structure (M(r) 9 x 10(6); 100 S). It dissociates in the pressure range of 0.4-2.5 kbar, as observed by spectroscopic methods (light scattering and intrinsic fluorescence) and gel filtration. In contrast to what is seen with smaller proteins, especially dimers, the pressure-dissociation curves for hemocyanin show little dependence on concentration, suggesting that native hemocyanin exists as a population of molecules with different free energies of association. The pressure-induced dissociation results from an equilibrium in which each aggregate responds to pressure independently of the others and, at any given pressure, is in one of two states, whole or dissociated, which persists for long times when compared with the duration of the experiment. The subunit-subunit affinity of dissociated hemocyanin is much lower than that of associated subunits, suggesting that a conformational drift of monomers occurs. When hemocyanin undergoes dissociation in the absence of calcium and at high pH (> 7.2), a large fraction of the dissociated products changes to a conformation that generates stable intermediate states of assembly, lacking the ability to fully reassemble into decamers and didecamers. These intermediates consist primarily of dimers (M(r) 900,000), and they bind oxygen reversibly with a higher affinity than the native hemocyanin. The binding of calcium or protons changes the conformation back to the "associable" state, which finally generates the assembled structure. The dissociation process is highly reversible at low pH (6.8-6.0) or in the presence of millimolar concentrations of calcium. At pH 5.7, dissociation is negligible at pressures up to 2.5 kbar. A decrease in pH from 7.6 to 6.6 increases the half-dissociation pressure (p 1/2) by 1.3 kbar, corresponding to a stabilization of 1.35 kcal per mole of subunit. The effects of Ca2+ and H+ may mean that, in vivo, special ionic conditions or other factors are required to be present at the assembly sites of oligomeric proteins such as hemocyanin.

[Primary malignant tumors of the vermiform appendix: clinico-pathologic study of 8 cases]. / Tumores malignos primários do apêndice vermiforme: estudo clínico patológico de oito casos.

In Botucatu, São Paulo, Brazil, 8 cases of primary tumors were encountered among 895 operated vermiform appendices: Five were colonic type adenocarcinomata and occurred above 40 years of age and three were carcinoids all in persons aged 25 or less. The diagnosis of appendical adenocarcinoma is almost never realized preoperatively. The importance of frozen sections in all suspicious cases is stressed since right hemicolectomy is the treatment of choice in cases of adenocarcinoma of the appendix. When malignant lesion goes unrecognized at initial operation, secondary hemicolectomy may be justified if histology shows invasion beyond the submucosa, at the line of ressection, or in lymph nodes. However, since the tumors is restricted to the mucosa, the patient must be followed with periodical radiology and endoscopy. In carcinoids limited to the appendix appendectomy is the treatment of choice.