Drosophila dSAP18 is a nuclear protein that associates with chromosomes and the nuclear matrix, and interacts with pinin, a protein factor involved in RNA splicing

SAP18 is a highly conserved protein that was proposed to be involved in multiple cellular processes from autophagy to gene regulation and mRNA processing. In this paper we show that, in Drosophila, dSAP18 is a predominantly nuclear protein that associates to both chromosomes and the nuclear matrix. dSAP18 becomes nuclear early during development, at the onset of cellularization, and remains so all through embryo development. dSAP18 is also nuclear in salivary glands, ovaries and cultured S2 cells. Here we also show that dSAP18 forms a complex with the Drosophila homolog of pinin (dPnn), a protein factor involved in mRNA splicing. dSAP18-dPnn interaction was confirmed in vivo, through co-immunoprecipitation experiments, as well as in vitro, through GST pull-down assays. These results are discussed in the context of the possible functions played by SAP18.     

Cytogenetics of a new cytotype of African Mus (subgenus Nannomys) minutoides (Rodentia, Muridae) from Kenya: C- and G- banding and distribution of (TTAGGG) n telomeric sequences

We present the results of a cytogenetic study on Mus (Nannomys) minutoides from Kenya by means of C- and G- banding and in-situ fluorescence hybridization (FISH) to localize the telomeric sequences. The karyotype is characterized by the occurrence of several Rb chromosomes Rb(1.X), Rb(1.Y). Rb(2.17), Rb(3.13), Rb(4.10), Rb(5.11), Rb(6.7), Rb(8.12), not previously described for this species. This finding suggests a high level of chromosomal diversification, which means it is possible to consider this cytotype as a new, well-differentiated, chromosomal lineage within the subgenus. The C-banding of the metaphases illustrated conspicuous blocks of centromeric heterochromatin at the paracentromeric regions of all telocentric chromosomes. Centromeric heterochromatin is not visible on all biarmed chromosomes. Following hybridization with telomeric probes, bright interstitial telomeric sequence (ITS) fluorescence signals are evident at the pericentromeric area of all Rb chromosomes, with the exception of Rb(2.17). Considering the localization of the C-positive heterochromatin and of the telomeric sequences, the events leading to the Kenyan cytotype from an all-telocentric condition probably included two steps: first, fusion without loss of heterochromatin and pericentromeric telomeric sequences; second, the reduction of the C-positive satellite DNA followed by the amplification of telomeric sequences in the C-negative paracentromeric region of Rb chromosomes. The presence of a single Rb(2.17) without ITS indicates possible variations of this mechanism.     

Identification, characterization and biological activity of oxytocin receptor in the developing human penis

Although abnormalities of the male external genitalia (MEG) are a relatively common problem, little is known concerning the molecular mechanisms that finely regulate penile development. We report here the expression of the oxytocin receptor (OTR) gene by real-time RT-PCR in human fetal tissues (11th-12th week of gestation), including the MEG. The developing penis expressed a very high level of OTR mRNA, only a half log(10) unit lower than fetal central nervous system, used as a positive control. The OTR protein is also highly expressed (western, immunohistochemistry and binding studies) and immunolocalized both in the mesenchymal body and in the surrounding blood capillaries, which will later constitute penile trabeculae and sinusoids. Binding studies using [125I]oxytocin antagonist ([125I]OTA) in cultured human fetal penile smooth muscle cells (hfPSMC) revealed the presence of specific OTR with a high capacity and affinity for oxytocin (OT) and for OTA. Increasing concentrations of OT dose-dependently induced intracellular Ca2+ mobilization. Furthermore, OTR mediated an increase in the proliferation and the migration of hfPSMC. In conclusion, we demonstrate that in the developing human MEG, OTR is highly expressed and might be involved in coordinating timely and appropriate proliferation and migration of the penile cells. Thus, OTR might represent an additional target for investigating human fetal MEG organogenesis.     

Differential Effects of Thalidomide on Angiogenesis and Tumor Growth in Mice

Thalidomide, clinically used as an antiinflammatory and antitumoral drug, inhibited sponge-induced angiogenesis when administered systemically (100 mg/kg^–1) in mice. However, it failed to inhibit solid Ehrlich tumor in the same mouse strain. We have used functional, biochemical and histological parameters to assess neovascularization and fibrovascular tissue infiltration of the mice sponge granuloma. The neovascularization growth as detected by development of blood flow and hemoglobin content extracted from the implants showed that thalidomide inhibited fibrovascular tissue formation by 40%. The functional and biochemical parameters correlated well with the histological study. Thalidomide had no inhibitory effect in the development of Ehrlich tumor. The detection of this selective action using the same animal strain bearing two different processes, supports the hypothesis that rather than species specificity, thalidomide is tissue specific. This approach may be used to identify the specificity of other therapeutic agents against distinct angiogenesis-dependent diseases.     

Malignancy-associated allelic losses on the X-chromosome in foregut but not in midgut endocrine tumours

Information on genetic changes involved in the progression of gastroenteropancreatic (GEP) endocrine tumours is scanty. On the other hand, the identification of molecular markers of malignancy could be crucial for the prognostic evaluation of these neoplasms, which is hardly predictable on the basis of conventional histological criteria. An association of X-chromosome deletions with malignancy has already been found in gastric endocrine tumours. To investigate this further, a comparative loss of heterozygosity (LOH) analysis was performed on 17 pancreatic endocrine tumours (PETs) and 17 intestinal (ten ileal, six appendiceal, and one rectal) carcinoids from female patients. The relationship of X-chromosome LOH with the ploidy status of the neoplasms was also investigated. LOH was found in six of eight malignant PETs (60% of the informative markers), but was infrequent in the nine benign ones (4.5%). In contrast, although retention of heterozygosity was consistently observed in benign midgut tumours, LOH was infrequent in malignant carcinoids (15%). No correlation was found between LOH and the ploidy status. These results indicate an association between X-chromosome LOH and malignancy in foregut endocrine tumours. The lack of such an association in midgut carcinoids suggests that different molecular mechanisms are involved in the progression of these two categories of endocrine neoplasms, which are otherwise considered to be closely related. These findings emphasize the need for further molecular studies on GEP endocrine tumours, carefully subdivided according to their anatomical site of origin.     

Age and sex influence on oxidative damage and functional status in human skeletal muscle

A reduction in muscle mass, with consequent decrease in strength and resistance, is commonly observed with advancing age. In this study we measured markers of oxidative damage to DNA, lipids and proteins, some antioxidant enzyme activities as well Ca²⁺ transport in sarcoplasmic reticulum membranes in muscle biopsies from vastus lateralis of young and elderly healthy subjects of both sexes in order to evaluate the presence of age- and sex- related differences. We found a significant increase in oxidation of DNA and lipids in the elderly group, more evident in males, and a reduction in catalase and glutathione transferase activities. The experiments on Ca²⁺ transport showed an abnormal functional response of aged muscle after exposure to caffeine, which increases the opening of Ca²⁺ channels, as well a reduced activity of the Ca²⁺ pump in elderly males. From these results we conclude that oxidative stress play an important role in muscle aging and that oxidative damage is much more evident in elderly males, suggesting a gender difference maybe related to hormonal factors.This revised version was published online in September 2005 with corrections to the Cover Date.     

Utility of cytokeratin 20 in identifying the origin of metastatic carcinomas in effusions

Using a commercially available monoclonal antibody (K_s20.1) and the avidin-biotin peroxidase method on cytospins and cell blocks, we analyzed cytokeratin (CK) 20 expression in 169 serous effusions. Cytoplasmic staining was observed in 44/151 malignant fluids. Colon, gastric, and pancreatic adenocarcinomas and mucinous ovarian tumors were most frequently positive. Single cases of transitional-cell and squamous cell carcinomas were reactive as well. Lung and breast cancers were mostly negative. Nonmucinous ovarian tumors were invariably unlabeled as were mesotheliomas and normal mesothelial cells. the study shows that CK 20 is valuable in distinguishing tumor cell origin in effusions. in particular, it identifies a set of carcinomas with the majority arising from the gastrointestinal tract, and represents a highly characteristic marker for colorectal cancer. © 1995 Wiley- Liss, Inc.     

Surface properties and cell response of low metal ion release Ti-6Al-7Nb alloy after multi-step chemical and thermal treatments

Ti-6Al-7Nb samples treated by innovative multi-step chemical and thermal processes were characterized in order to evaluate their surface properties and cell interaction. The main object was to asses if the treatments were effective in order to obtain a surface presenting at the same time bone-like apatite induction ability, low metal ion release, good cell response and high protein binding. The morphology, crystallographic structure, porosity and wettability of the treated materials were investigated, as well as their interaction with simulated body fluid during soaking for different times. Cytotoxicity, protein adsorption tests and in vitro fibroblast and osteoblast-like cell cultures were also performed.     

Exhaled breath condensate cysteinyl leukotrienes are increased in children with exercise-induced bronchoconstriction

BACKGROUND: It is recognized that airway inflammation has a central role in the pathogenesis of asthma, but how it relates to exercise-induced bronchoconstriction (EIB) is not completely understood. OBJECTIVE: The aim of our study was to investigate the relationship between EIB and baseline concentrations of cysteinyl leukotrienes (Cys-LTs) and other inflammatory markers in exhaled breath condensate (EBC). METHODS: EBC was collected, and the fraction of exhaled nitric oxide (FE NO ) was measured in a group of 19 asthmatic children, after which they performed a treadmill exercise test. Fourteen healthy children were enrolled as control subjects. RESULTS: The asthmatic children were divided into the EIB group (decrease in FEV 1 , > or =12%) and the non-EIB group. The EBC was analyzed for the presence of Cys-LTs, leukotriene B 4 , and ammonia. Asthmatic patients with EIB (mean FEV 1 decrease, 23% +/- 3%) had higher Cys-LT concentrations than either asthmatic patients without EIB or control subjects (42.2 pg/mL [median] vs 11.7 pg/mL and 5.8 pg/mL; P < .05 and P < .001, respectively). Ammonia concentrations were lower in both the EIB and non-EIB groups than in control subjects (253.2 microM and 334.6 microM vs 798.4 microM; P < .01 and P < .05, respectively). No difference in EBC leukotriene B 4 levels was found among the 3 groups. Both asthmatic groups had higher FE NO levels than control subjects ( P < .001). EBC Cys-LT ( P < .01; r = 0.7) and FE NO ( P < .05; r = 0.5) values both correlated significantly with the postexercise FEV 1 decrease. CONCLUSION: this study shows that EBC Cys-LT values are higher in asthmatic children with EIB and correlate with the decrease in FEV 1 after exercise. These findings suggest that the pathways of both Cys-LT and nitric oxide are involved in the pathogenesis of EIB.     

Influence of the histamine control on skin reactivity in skin testing

We investigated the effect of the histamine control (1 mg/ml) on the results of skin prick and intradermal testing with bee and wasp venom. Skin tests were done on the patients' forearms: on the right arm the histamine control and the bee venom dilutions, on the left arm the wasp venom dilutions only, at distances of 4-5 cm. In intradermal testing 11 (9%) of 122 patients showed a positive wheal and flare reaction to the bee venom solution positioned next to the histamine control. The subsequent solutions in higher concentrations did not produce any skin reactions. The results of intradermal testing with bee venom did not occur in intradermal testing with wasp venom or in skin prick testing with both allergens. Our results show clearly that in skin prick tests a distance of 4-5 cm is sufficient to avoid false positive skin reactions. However, using the same distance in intradermal testing showed that histamine affects the skin reactions produced by adjacent allergen solutions. Therefore false positive results may occur.