PERSPECTIVE: Pollen Cryopreservation for Plant Breeding and Genetic Resources Conservation.

Pollen conservation is an important tool for the maintenance of plant genetic resources and can promote improved efficiency in breeding programs and germplasm conservation and exchange. This review aims to understand the importance of pollen cryopreservation and how to use it for distinct species in order to encourage the use of this methodology in germplasm banks and plant breeding programs. Pollen from many plant species have already been successfully cryopreserved in liquid nitrogen. Analogous with other plant structures, to maintain pollen viability after storage at ultra-low temperatures it is necessary to adjust the water content so that at least the freezable is removed. Optimum pollen moisture levels for cryopreservation varies among species and different methods have been applied to control moisture content. Common methods to decrease pollen moisture content include exposure to saturated solutions of various salts (which have a well-defined relative humidity), silica gel, dry air or treatment with vitrification solutions. It is our understanding that pollen cryopreservation is a safe and practical alternative for conserving genetic material that is often neglected by potential users. The technique has the potential to overcome challenges of breeding programs, such as flowering asynchrony between different parent genotypes, and the production of insufficient pollen in nature. Generally, pollen cryopreservation techniques tend to be simple enough to be used routinely in research, plant breeding and germplasm conservation programs.

Genotoxic potential of leaf extracts of Jatropha gossypiifolia L.

Jatropha gossypiifolia L. (Euphorbiaceae) is widely used in popular medicine. However, further toxicological studies are necessary for its reliable use. The present study aimed to evaluate the cytotoxic, genotoxic, and mutagenic effects of ethanolic and aqueous leaf extracts of J. gossypiifolia, using the test system Allium cepa. In addition, the phytochemical profile of the extracts was also obtained. Seeds of A. cepa were subjected to different concentrations of the two extracts (0.001, 0.01, 0.1, 1, and 10 mg/mL). Distilled water was used for the negative control and methyl methanesulfonate (4 x 10(-4) M) and trifluralin (0.84 ppm) for the positive controls. The values of mitotic index at all concentrations of ethanolic extract and at 0.1, 1, and 10 mg/mL aqueous extract showed a significant decrease. Alterations, such as chromosome adherence, C-metaphases, chromosome bridges, nuclear buds, and micronuclei were verified in both extracts but chromosome loss indicating genotoxic activity was observed only in the ethanolic extract. Presence of micronuclei on administration of the extracts, also indicated mutagenic action at the chromosome level. In the ethanolic extract, aneugenicity seemed to be the main activity, probably as a result of the action of terpenes and/or flavonoids, whereas in the aqueous extract, clastogenic action appeared to be the principal activity, presumably as a consequence of the effect of flavonoids and/or saponins. Thus, we suggest that the extracts of this species should be used with great caution for medicinal purpose.

Indomethacin attenuates mechanical allodynia during the organization but not the maintenance of the peripheral neuropathic pain induced by nervus ischiadicus chronic constriction injury.

The neurochemical mechanisms underlying neuropathic pain (NP) are related to peripheral and central sensitization caused by the release of inflammatory mediators in the peripheral damaged tissue and ectopic discharges from the injured nerve, leading to a hyperexcitable state of spinal dorsal horn neurons. The aim of this work was to clarify the role played by cyclooxygenase (COX) in the lesioned peripheral nerve in the development and maintenance of NP by evaluating at which moment the non-steroidal anti-inflammatory drug indomethacin, a non-selective COX inhibitor, attenuated mechanical allodynia after placing one loose ligature around the nervus ischiadicus, an adaptation of Bennett and Xie's model in rodents. NP was induced in male Wistar rats by subjecting them to chronic constriction injury (CCI) of the nervus ischiadicus, placing one loose ligature around the peripheral nerve, and a sham surgery (without CCI) was used as control. Indomethacin (2 mg/kg) or vehicle was intraperitoneally and acutely administered in each group of rats and at different time windows (1, 2, 4, 7, 14, 21, and 28 days) after the CCI or sham surgical procedures, followed by von Frey's test for 30 min. The data showed that indomethacin decreased the mechanical allodynia threshold of rats on the first, second, and fourth days after CCI (P<0.05). These findings suggested that inflammatory mechanisms are involved in the induction of NP and that COX-1 and COX-2 are involved in the induction but not in the maintenance of NP.

Role of carbonate burial in Blue Carbon budgets.

Calcium carbonates (CaCO3) often accumulate in mangrove and seagrass sediments. As CaCO3 production emits CO2, there is concern that this may partially offset the role of Blue Carbon ecosystems as CO2 sinks through the burial of organic carbon (Corg). A global collection of data on inorganic carbon burial rates (Cinorg, 12% of CaCO3 mass) revealed global rates of 0.8 TgCinorg yr-1 and 15-62 TgCinorg yr-1 in mangrove and seagrass ecosystems, respectively. In seagrass, CaCO3 burial may correspond to an offset of 30% of the net CO2 sequestration. However, a mass balance assessment highlights that the Cinorg burial is mainly supported by inputs from adjacent ecosystems rather than by local calcification, and that Blue Carbon ecosystems are sites of net CaCO3 dissolution. Hence, CaCO3 burial in Blue Carbon ecosystems contribute to seabed elevation and therefore buffers sea-level rise, without undermining their role as CO2 sinks.

Towards (99m)Tc-based imaging agents with effective doxorubicin mimetics: a molecular and cellular study.

Doxorubicin is a clinical benchmark drug, which is applied in the treatment of numerous cancers. Known for its accumulation in the nucleus and ability to intercalate into DNA, it targets quickly dividing i.e. hypermitotic cells. Through this mechanism, it could be an ideal structural motif for a new class of imaging agents, given that the new entity approximates the in vitro profile of the parent drug. Here we describe design, synthesis and biological activity of a small array of Doxorubicin-metalloconjugates (M = (99m)Tc, Re). We demonstrate that the conjugates preferably accumulate in the nuclear compartment, tightly bind to DNA and retain an appreciable cytotoxicity. Moreover, the Re conjugates effectively act as inhibitors of the human Topoisomerase II enzyme, which is the widely accepted mechanism of action of the parent drug. Since the conjugates effectively mimic the in vitro behavior of native Doxorubicin, the (99m)Tc compounds are prospective imaging agents.

Indomethacin attenuates mechanical allodynia during the organization but not the maintenance of the peripheral neuropathic pain induced by nervus ischiadicus chronic constriction injury

The neurochemical mechanisms underlying neuropathic pain (NP) are related to peripheral and central sensitization caused by the release of inflammatory mediators in the peripheral damaged tissue and ectopic discharges from the injured nerve, leading to a hyperexcitable state of spinal dorsal horn neurons. The aim of this work was to clarify the role played by cyclooxygenase (COX) in the lesioned peripheral nerve in the development and maintenance of NP by evaluating at which moment the non-steroidal anti-inflammatory drug indomethacin, a non-selective COX inhibitor, attenuated mechanical allodynia after placing one loose ligature around the nervus ischiadicus, an adaptation of Bennett and Xie's model in rodents. NP was induced in male Wistar rats by subjecting them to chronic constriction injury (CCI) of the nervus ischiadicus, placing one loose ligature around the peripheral nerve, and a sham surgery (without CCI) was used as control. Indomethacin (2 mg/kg) or vehicle was intraperitoneally and acutely administered in each group of rats and at different time windows (1, 2, 4, 7, 14, 21, and 28 days) after the CCI or sham surgical procedures, followed by von Frey's test for 30 min. The data showed that indomethacin decreased the mechanical allodynia threshold of rats on the first, second, and fourth days after CCI (P<0.05). These findings suggested that inflammatory mechanisms are involved in the induction of NP and that COX-1 and COX-2 are involved in the induction but not in the maintenance of NP.

Analgesia by direct antagonism of nociceptor sensitization involves the arginine-nitric oxide-cGMP pathway.

We tested the hypothesis that activation of the nitric oxide (NO)-cGMP pathway is involved in the mechanism of two directly acting non-opiate peripheral analgesics, myrcene and dipyrone, using our modification of the Randall-Selitto test. The NO inhibitor, NG-monomethyl-L-arginine (50 micrograms/paw) and methylene blue (500 micrograms/paw) abolished the analgesic effect of dipyrone and myrcene. Dibutyryl cyclic adenosine monophosphate (DbcAMP) caused a dose-dependent hyperalgesia (20, 50 and 100 micrograms/paw). Only responses to low doses of DbcAMP were inhibited by the two analgesics. Pretreatment with MY5445 (50 micrograms/paw) resulted in potentiation of the effects of both analgesics. These results support our hypothesis that the sensitivity of nociceptors may be controlled by the balance between the levels of cAMP and cGMP. Stimulation of the NO-cGMP pathway is probably the common denominator for the mode of action of peripheral analgesics which block hyperalgesia directly.

Immunohistochemical distinction of high-grade mucoepidermoid carcinoma and epidermoid carcinoma of the parotid region.

The correct diagnosis of high-grade mucoepidermoid (MEC), which is composed of solid islands of intermediate and squamous cells, may be challenging, due to its similarity to other tumours, mainly with squamous cell carcinoma (SCC). The present report employed immunohistochemical technique against different cytokeratins (CKs), in order to differentiate these two entities. : Six high-grade MEC and six SCC of the parotid region, retrieved from the files of both Oral Pathology Department of the School of Dentistry of University of São Paulo and Pathology Department of A.C. Camargo Hospital, were submitted immunohistochemical technique against Cks 7,8, 10, 13, 14 and 19. : High-grade MEC was positive for Cks 7, 8, 13, 14 and 19. The cases of SCC showed strong positivity for CK14, and CK10 was present only in focal areas. Our results highlight the use of CKs (especially CK14) to differentiate high-grade MEC and SCC.

Methods to assess the viability of cryopreserved Jatropha curcas L. seed germplasm / Métodos para avaliar a viabilidade de germoplasma semente criopreservado de Jatropha curcas L

ABSTRACT Jatropha curcas L. is a plant species with many potential applications, especially medicinal uses (hypoglycemic, anti-inflammatory, haemostatic, healing, anti-tumor). The objective of this study was to test germination in moist paper rolls for whole seeds and in vitro for excised embryonic axes, in an attempt to identify the best method to assess the quality of J. curcas seed germplasm, cryopreserved with different water contents. The experimental sample with a 6.2% moisture content (MC) was divided in subsamples which were hydrated and dehydrated for 0 (control), 4, 8, 11 and 24h. The initial germination percentages were 63% for whole seeds and 81% for excised embryonic axes. After exposure to liquid nitrogen (LN), germination percentages were 48% (whole seeds) and 57% (excised embryonic axes). There was no significant difference between germination percentages in embryonic excised from seeds subjected or not subjected to freezing, with different MC. In contrast, there was a reduction of the whole seed germination percentage when exposed to LN (contrast = 0.17, standard error = 0.04, t = 4.09, p = 0.001) and not for the hydration and dehydration treatments. The methodology based on in vitro cultures of the embryonic axis isolated from seeds stored in LN with distinct MC values was more efficient than the standard germination test to evaluate the viability of J. curcas seeds before and after LN storage.

RESUMO Jatropha curcas L., é uma espécie com várias aplicações potenciais, principalmente para usos medicinais (hipoglicemina, anti-inflamatório, homeostático, cicatrizante, antitumoral). O objetivo deste estudo foi testar a germinação em rolo de papel para sementes inteiras e in vitro para eixos embrionários excisados visando identificar o melhor método para avaliar a qualidade de germoplasma semente de J. curcas, criopreservado com diferentes teores de água. A amostra experimental com 6,2% de teor de água foi dividida em subamostras que foram hidratadas e desidratadas por 0 (controle), 4, 8, 11 e 24 h. Os percentuais de germinação inicial foram de 63% para sementes inteiras e de 81% para eixos embrionários excisados. Após exposição ao nitrogênio líquido (NL) os percentuais de germinação foram de 48% (sementes inteiras) e 57% (eixos embrionários). Não houve diferença significativa entre os percentuais de germinação de eixos embrionários excisados de sementes com diferentes umidades e submetidas ou não ao congelamento. Em contraste, houve redução de percentuais de germinação das sementes inteiras expostas ao NL (contraste = 0.17, erro padrão = 0.04, t = 4.09, p = 0.001), mas não aos tratamentos de hidratação e desidratação. A metodologia baseada em cultura de eixos embrionários in vitro isolados de sementes armazenadas em NL, com distintos teores de água foi mais eficiente que a germinação padrão para avaliar a viabilidade de sementes J. curcas antes e após a armazenamento em NL.

Uso del aparato bucal "PMpositioner" en el tratamiento del ronquido y la apnea obstructiva del sueño / Use of PMpositioner oral appliance in the treatment of snoring and mild obstructive sleep apnea

La elección de un aparato bucal apropiado para lograr los mejores resultados en el tratamiento de la apnea obstructiva del sueño es importante. El objetivo de este estudio fue evaluar el efecto de un aparato bucal específico, el PMPositioner, para el tratamiento del ronquido y la apnea obstructiva del sueño leve, a través de polisomnografía y la Escala de Epworth del sueño, después de seis meses de uso del mencionado aparato. Se incluyeron en el estudio 17 pacientes divididos en dos grupos: un grupo de roncadores (n=7) y otro grupo (n=10) con apnea obstructiva leve. Los resultados fueron significativos para el segundo grupo, revelando una disminución en el índice de apnea-hipoapnea de 7,4 +- 5,0 a 3,0 +- 2,5 (p<0.05), aumento del sueño REM de 16,0+-4,0 a 19+-6,0 y una mejora de la somnolencia en la Escala Epworth de 12,5+-5,4 a 7,4+-2,4. Se constató una disminución en los ronquidos y los síntomas subjetivos. PMPositioner, fue efectivo en el tratamiento de los ronquidos y la apnea obstructiva leve, la reducción de la somnolencia y de otros síntomas.

The choice of an adequate oral appliance is very important in the treatment of obstructive sleep apnea. The present study evaluated the effect of PMPositioner for the treatment of snoring and mild obstructive sleep apneathrough polysomnography and Epworth Sleep Scale prior to treatment and after six months. Seventeen patients, divided into 2 groups, snoring (n=7) and 10 with mild obstructive sleep apnea were enrolled. The results were significant for obstructive sleep apnea group reveling a decrease in the apnea/hypopnea index from 7.4±5.0 to 3.0±2.5 (p<0.05), anincrease in oxigen saturation from 88.0±6.0 to 90.0±2.8 (p<0.05), an increase in REM sleep from 16.0±6.0 to 19±4.0 and a sleepiness improved in from 12.5±5.4 to 7.4±2.4. Furthermore, it was noticed an improvement in snoring and subjective symptoms. The PM Positioner is efficient in the treatment of snoring and mild obstructive sleep apnea and in reduction of sleepness and others symptoms.

Factors influencing contralateral lymph node metastasis from oral carcinoma.

BACKGROUND: An ipsilateral neck dissection is mandatory during initial treatment stages II-IV oral carcinomas. However, no consensus exists whether or not to perform an elective contralateral neck dissection. METHODS: Five hundred thirteen consecutive cases of squamous cell carcinoma (269 tongue, 135 floor of the mouth, 44 inferior gingiva, 65 retromolar trigone) were reviewed. Tumor stages were: 69 T1, 227 T2, 217 T3-T4, 263 N0, 250 N1-N3. A total of 563 neck dissections were performed in 448 patients. Univariate and multivariate analysis of risk factors were performed using logistic regression. RESULTS: Two hundred twenty-three patients (49.8%) had positive nodes in the specimen (182 ipsilateral, 36 bilateral, 5 contralateral). Contralateral neck recurrences occurred in 38 cases (33 not submitted to a contralateral neck dissection initially). Multivariate logistic regression analysis demonstrated that clinical stage (p = .0001), tumor crossing midline (p = .0011), and floor of the mouth involvement (p = .0236) were the most important predictors of contralateral metastasis. CONCLUSION: The contralateral side of the neck is a common and potentially preventable site of recurrence in tumors of the oral cavity. The multivariate model obtained discriminates patients with low and high risk (more than 20%) of contralateral metastasis. The application of this mathematical model can be useful for the indication of contralateral neck dissections, because not all tumors crossing midline are associated to a high risk (stages I and II tumors not involving the floor of the mouth) and not all tumors not crossing midline are at low risk (stages III and IV tumors involving the floor of the mouth).

Ulcera gastroduodenal perfurada: resultados imediatos do tratamento cirúrgico / Perforated gastric and duodenal ulcer: immediate results of surgical treatment

Säo relatados os resultados imediatos em 26 casos de úlcera gastroduodenal perfurada, operados no Hospital de Pronto Socorro da FUSAM, num período de 3 anos. A perfuraçäo ocorreu, em mais da metade dos pacientes (57,7%), na face anterior do duodeno. A técnica cirúrgica preferencialmente utilizada foi a sutura da perfuraçäo, associada ou näo à epiploplastia (53,8%). Ocorreram complicaçöes pós-operatórias em 7 pacientes (26,9%) e a mortalidade foi de 11,6%. Em relaçäo à mortalidade, houve uma diferença significativa (p < 0.05) entre os pacientes situados nas faixas etárias superior e inferior a 60 anos e entre os operados antes e após 48 horas do início dos sintomas. Os índices de complicaçöes e mortalidade correlacionaram-se diretamente com a idade do paciente, o grau de contaminaçäo peritoneal e o período decorrido entre o ínicio dos sintomas e a operaçäo, independentemente do tipo de cirurgia realizada ou do local da perfuraçäo