Chronology and pattern of replication in the bone marrow chromosomes of Gallus domesticus

The duration of the cell generation, the chronology, and the pattern of chromosome duplication was studied in the bone marrow of Gallus domesticus. The duration of the phases of the cell cycle is: cell generation 17.5 hours, S period 9 hours. G₂ period plus prophase stage 2.5 hours, G₁ period 6 hours. Chromosome replication begins at many sites. During middle S it extends to the whole complement and finally finishes in small, late replicating regions of the macrochromosomes. Interchromosomal asynchrony of duplication at the initiation or at the end of the S period was not observed. Z-chromosomes begin and finish DNA synthesis synchronously with the other macrochromosomes. The W-chromosome in females is the last microchromosome to finish replication. However it ends DNA synthesis at about the same time as the macrochromosomes. Similarities and differences between chromosome replication in Aves and Mammalia are considered.     

NDVI Spatio-temporal Patterns and Climatic Controls Over Northern Patagonia

Ecosystems - In this study, we identify the main modes of variability of the Normalized Difference Vegetation Index (NDVI) and their relationships with precipitation and temperature variations...     

Female‐driven intersexual coevolution in beetle genitalia

Genital coevolution is a pervasive phenomenon as changes in one sex tend to impose fitness consequences on the other, generating sexual conflict. Sexual conflict is often thought to cause stronger selection on males due to the Darwin–Bateman's anisogamy paradigm. However, recent studies have demonstrated that female genitalia may be equally elaborated and perform diverse extra‐copulatory functions. These characteristics suggest that female genitals can also be primary targets of selection, especially where natural selection acts on female‐exclusive functions such as oviposition. Here, we test this hypothesis in a statistical phylogenetic framework across the whole beetle (Coleoptera) phylogeny, investigating whether coevolution of specific genital traits may be triggered by changes in females. We focus on traits of the proctiger, which composes part of the male terminalia and the female ovipositor. Our results present a comprehensive case of male–female genital coevolution and provide solid statistical evidence for a female‐initiated coevolutionary process where the vast majority of evolutionary transitions in males have occurred only after changes in females. We corroborate the hypothesis that female traits may change independently and elicit counter‐adaptations in males. Furthermore, by showing a consistent pattern across the phylogeny of the most diverse group of animals, our results suggest that this female‐driven dynamics may persist through long time scales.     

Gibberellin reverses the negative effect of paclobutrazol but not of chlorocholine chloride on the expression of SGs/GAs biosynthesis-related genes and increases the levels of relevant metabolites in Stevia rebaudiana

Plant Cell, Tissue and Organ Culture (PCTOC) - Steviol glycosides (SGs) and gibberellins (GAs) share the same molecular basis. However, the coordination of their respective biosynthetic pathways is...     

Glucose Accelerates Copper- and Ceruloplasmin-induced Oxidation of Low-density Lipoprotein and Whole Serum

Glucose at pathophysiological concentrations was able to accelerate copper-induced oxidation of isolated low-density lipoprotein (LDL) and whole serum. The efficiency of glucose was favored under the following circumstances: (a) when LDL oxidation was induced by low copper concentration, (b) when LDL was partly oxidized, i.e. enriched with lipid peroxides. The glucose derivative methyl- &#102 - d -glucoside was ineffective on Cu 2+ -induced LDL oxidation, pointing out the essential role of the reactivity of the aldehydic carbon for the pro-oxidative effect. When LDL oxidation was induced by a peroxyl radical generator, as a model of transition metal independent oxidation, glucose was ineffective. Glucose was found to stimulate oxidation of LDL induced by ceruloplasmin, the major copper-containing protein of human plasma. Thus, glucose accelerated oxidation of LDL induced by both free and protein bound copper. Considering the requirement for catalytically active copper and for the aldehydic carbon, the pro-oxidative effect of glucose is likely to depend on the increased availability of Cu + ; this is more efficient in decomposing lipid peroxide than Cu 2+ , accounting for acceleration of LDL oxidation. The possible biological relevance of our work is supported by the finding that glucose was able to accelerate oxidation of whole serum, which was assessed by monitoring low-level chemiluminescence associated with lipid peroxidation.     

Contrasting breeding systems in six species of Tillandsia L. (Bromeliaceae) from woody areas of Santa Fe Province: Argentina

The reproductive biology of six native Tillandsia species that co-occurred in woody areas of Santa Fe Province (Argentina) was studied for floral biology, breeding systems and reproductive success. Flower longevity, floral phases, hand self- and cross-pollinations or natural pollinations and fluorescence microscopy observations of post-pollination events were analysed. Also pollen/ovule (P/O) ratio and pre-emergent reproductive success (PERS) were compared between species. In T. aëranthos, T. ixioides and T. meridionalis, self-pollinated flowers mostly failed to form fruits, and fluorescence microscopy studies showed that in selfed pistils pollen tube growth was arrested in the style. It is likely that these species have homomorphic, gametophytic self-incompatibility. In contrast, T. capillaris, T. tricholepis and T. recurvata regularly formed fruits following autonomous self-pollination. Floral traits, the P/O ratios and PERS indices correlate with the breeding systems found in these two groups of species: the three selfing species have inconspicuous closed flowers, and they have low P/O ratios and high PERS values. In contrast, the three self-incompatible (SI) species have conspicuous flowers with relatively high P/O and low PERS values. We described here three new cases of SI in Tillandsia species subgenera Anoplophytum and confirm the autogamous and cleistogamous status in three species of Tillandsia subgenera Diaphoranthema.     

Intracavitary Immunotherapy and Chemotherapy for Upper Urinary Tract Cancer: Current Evidence

A review of the literature was performed to summarize current evidence regarding the efficacy of topical immunotherapy and chemotherapy for upper urinary tract urothelial cell carcinoma (UUT-UCC) in terms of post-treatment recurrence rates. A Medline database literature search was performed in March 2012 using the terms upper urinary tract, urothelial cancer, bacillus Calmette-Guérin (BCG), and mitomycin C. A total of 22 full-text articles were assessed for eligibility, and 19 studies reporting the outcomes of patients who underwent immunotherapy or chemotherapy with curative or adjuvant intent for UUT-UCC were chosen for quantitative analysis. Overall, the role of immunotherapy and chemotherapy for UUT-UCC is not firmly established. The most established practice is the treatment of carcinoma in situ (CIS) with BCG, even if a significant advantage has not yet been proven. The use of BCG as adjuvant therapy after complete resection of papillary UUT-UCC has been studied less extensively, even if recurrence rates are not significantly different than after the treatment of CIS. Only a few reports describe the use of mitomycin C, making it difficult to obtain significant evidence.Key words: Upper urinary tract, Urothelial cell carcinoma, Bacillus Calmette-Guérin, Mitomycin C, Chemotherapy, ImmunotherapyAccording to the 2011 update of the European Guidelines for the diagnosis and management of upper urinary tract urothelial cell carcinoma (UUT-UCC),¹ urothelial carcinomas are the fourth most common tumors after prostate and breast cancer, lung cancer, and colorectal cancer. Bladder tumors account for 90% to 95% of urothelial carcinomas; UUT-UCC are relatively uncommon and account for only 5% to 10% of urothelial carcinomas. The annual incidence of UUT-UCC in Western countries is approximately one or two new cases per 100,000 inhabitants. Pyelocaliceal tumors are approximately twice as common as ureteral tumors. In 8% to 13% of cases, concurrent bladder cancer is present, and 60% of UUT-UCC are invasive at diagnosis, compared with only 15% of bladder tumors. This kind of carcinoma has a peak incidence in people in their 70s and 80s, with a higher prevalence in men.Radical nephroureterectomy (RNU) with excision of the bladder cuff represents the gold standard treatment for UUT-UCC, regardless of the location of the tumor in the upper urinary tract.¹ Lymph node dissection associated with RNU is of therapeutic interest and allows for optimal staging of the disease.Conservative surgery for low-risk UUT-UCC allows for preservation of the upper urinary renal unit; conservative management can be considered in imperative cases (renal insufficiency, solitary functional kidney) or in elective cases (ie, when the contralateral kidney is functional) for low-grade, low-stage tumors. Endoscopic ablation can be considered if a flexible ureteroscope, laser generator, and pliers (pluck) for biopsies are available, if the patient is informed of the need for closer follow-up, and if a complete resection is advocated.Segmental ureteral resection with wide margins provides adequate pathologic specimens for definitive staging and grade analysis while also preserving the ipsilateral kidney. Segmental resection is possible for the treatment of low- and high-risk tumors of the distal ureter, whereas segmental resection of the iliac and lumbar ureter is associated with a greater failure rate. Open resection of tumors of the renal pelvis or calices has almost disappeared.Percutaneous management can be considered for low-grade or noninvasive UUT-UCC that are inaccessible or difficult to manage by ureteroscopy, even if a theoretical risk of seeding exits in the puncture tract and if perforations occur during the procedure.After conservative treatment of UUT-UCC or for the treatment of carcinoma in situ (CIS), the instillation of bacillus Calmette-Guérin (BCG) or mitomycin C (MMC) is technically feasible by means of a percutaneous nephrostomy or even through a ureteric stent.Different agents have been used for topical therapy, including BCG, MMC, epirubicine, and thiotepa. Topical chemotherapeutic agents can be administered after endoscopic management, whereas instillations of BCG need to be postponed until the urothelium heals to avoid systemic side effects.According to a recent review,² topical therapy appears to be safe, although its efficacy is debatable. Complications from the administration of topical immunotherapy or chemotherapy can be avoided by maintaining low intracavitary pressures during administration. Renal function does not seem to be impaired after instillation of BCG or MMC.³ No systemic side effects result from perfusion with MMC, and persistent fever was reported in 5% of patients in combined major series after BCG administration; therefore, this side effect was resolved with appropriate antimicrobial therapy in all cases. Furthermore, up to 25% of patients may have granulomatous involvement of the urinary tract after BCG.This review summarizes current evidence about the efficacy of topical immunotherapy and chemotherapy in terms of post-treatment recurrence rates.