Congenital osteogenesis imperfecta in three sibs

Summary Three sibs of a Turkish family were affected with lethal congenital osteogenesis imperfecta (OI). The disease was characterized by extremely fragile bones and crumpled femora, but in contrast to reported cases of OI type II, relatively normal ribs with only few fractures. The children affected died shortly after birth. Although their parents both came from the same small village in Turkey, consanguinity could not be demonstrated. Our observations support that this disorder is inherited in an autosomal recessive mode. We consider the possibility that these patients represent either a new subgroup of OI type II (milder, although still lethal) or of type III (more severe).This investigation was supported in part by research grants from the Deutsche Forschungsgemeinschaft.     

Unistellate spermatozoa of decapods: comparative evaluation and evolution of the morphology

Decapod unistellate spermatozoa are primarily characterized by the presence of a single appendage (spike) extending from the acrosome. Among decapods, this type of spermatozoon is found only in shrimps of the families Sicyoniidae, Penaeidae, and Solenoceridae (suborder Dendrobranchiata) and of the infraorder Caridea (suborder Pleocyemata). This review comparatively discusses the morphological diversity of unistellate spermatozoal ultrastructure among these decapods, as well as the role of the primary structures involved in the fertilization and spermatozoal capacitation. Furthermore, the use of the unistellate spermatozoal ultrastructure to support phylogenetic relationships and of the current phylogenetic evidences to investigate the evolution of spermatozoa of decapods is discussed. Morphologically, the main differences between caridean and dendrobranchiate unistellate spermatozoa are the shape of the main body (inverted cup-shaped, and spherical, bulged or elongate, respectively) and complexity of the acrosomal region. The latter is directly related to the type of fertilization. For example, dendrobranchiates have more complex acrosomal regions than that carideans, and fertilization involves a visible acrosome reaction, which is not observed in carideans. Ultrastructural changes of spermatozoa throughout capacitation are unknown in carideans, but for dendrobranchiates generally occur in the acrosomal vesicle and subacrosomal region throughout attachment of the spermatophore to the thelycum, enabling fertilization by the spermatozoa. Comparative evaluation of spermatozoal morphology and current phylogenetic evidences corroborates the hypothesis that the spermatozoal spike of carideans and dendrobranchiates is the result of convergent evolution.     

Histoplasma capsulatum‐induced extracellular DNA trap release in human neutrophils

Neutrophils are leukocytes that are capable of eliminating both intra‐ and extracellular pathogens by mechanisms such as phagocytosis, degranulation, and release of neutrophil extracellular traps (NETs). Histoplasma capsulatum var. capsulatum (H. capsulatum) is a dimorphic fungus with a global distribution that causes histoplasmosis, a disease that is endemic in different geographic areas and is spreading worldwide. The release of NETs has been described as an important host defense mechanism against different fungi; however, there are no reports demonstrating that this process is implicated in neutrophil response to H. capsulatum infection. Therefore, the aim of this work is to investigate whether isolated human neutrophils release NETs in response to H. capsulatum and the potential mechanisms involved, as well as delineate the NETs antifungal activity. Using both confocal fluorescence and scanning electron microscopy techniques, we determined that NETs are released in vitro in response to H. capsulatum via an oxidative mechanism that is downstream of activation of the Syk and Src kinase pathways and is also dependent on CD18. NETs released in response to H. capsulatum yeasts involve the loss of neutrophil viability and are associated with elastase and citrullinated histones, however also can occur in a PAD4 histone citrullination independent pathway. This NETs also presented fungicidal activity against H. capsulatum yeasts. Our findings may contribute to the understanding of how neutrophils recognize and respond as immune effector cells to H. capsulatum, which may lead to better knowledge of histoplasmosis pathophysiology and treatment.     

<Emphasis Type="Italic">RASSF1A</Emphasis> expression level in primary epithelial tumors of various locations

Tumor suppressor activity of RASSF1A in vitro and in vivo was established, in particular, in studies of knockout mice cells. Data on methylation of the promoter region and a lower expression of RASSF1A were mostly obtained with cancer cell lines. Here, the RASSF1A mRNA was quantified the first time in primary epithelial malignant tumors of five various locations from 130 patients by semi-quantitative RT-PCR. Representative samples of kidney, lung, and breast carcinomas were examined. Preliminary data were obtained for RASSF1A expression in ovarian and colorectal carcinomas. System studies showed unexpected expression profiles, namely, the mRNA level increased (two- to sevenfold) more frequently than decreased in renal, breast, ovarian, and colorectal carcinomas. A higher RASSF1A mRNA level was significantly more frequent in renal cell carcinomas (24/38, 63% vs 8/38, 21%, P = 0.0004 by Fisher’s exact test) and ovarian carcinomas (8/13, 62% vs 2/13, 15%, P = 0.0114). Equal frequencies of lower and higher RASSF1A expression levels were only observed in non-small cell lung cancer (16/38, 42%). Noteworthy, an increase in expression was more common at early clinical stages of squamous cell lung cancer and adenocarcinoma, while a decrease in RASSF1A expression was more frequent at advanced clinical stages. In clear cell renal cell carcinoma, an increase in RASSF1A expression occurred more often at both early and advanced stages and was significant at advanced stages (P = 0.0094). The findings suggested tumor specificity for changes in RASSF1A expression. The observed regularities may also indicate that RASSF1A has dual functions in tumors, acting as a tumor suppressor and as a protooncogene.     

Glutathione and gamma-glutamyl transferases are involved in the formation of cadmium-glutathione complex

In a wild-type strain of Saccharomyces cerevisiae, cadmium induces the activities of both gamma-glutamyl transferase (gamma-GT) and glutathione transferase 2 (Gtt2). However, Gtt2 activity did not increase under gamma-GT or Ycf1 deficiencies, suggesting that the accumulation of glutathione-cadmium in the cytosol inhibits Gtt2. On the other hand, the balance between the cytoplasmic and vacuolar level of glutathione seems to regulate gamma-GT activity, since this enzyme was not activated in a gtt2 strain. Taken together, these results suggest that gamma-GT and Gtt2 work together to remove cadmium from the cytoplasm, a crucial mechanism for metal detoxification that is dependent on glutathione.