Toxicological assessment of kretek cigarettes Part 6: the impact of ingredients added to kretek cigarettes on smoke chemistry and in vitro toxicity.

Mainstream smoke (MS) from experimental kretek cigarettes with three ingredient mixes at low (typical use level) and high (2.5 or 3 times that level) inclusion rates was compared to a control kretek cigarette of identical construction (cloves and humectants), but without the addition of ingredients. 350 ingredients, commonly used in various combinations and in a limited number in a given brand in the manufacture of marketed kretek cigarettes were assessed. The MS composition of the kretek cigarettes was characterized by a comprehensive set of analytes (55 smoke constituents). Furthermore, the smoke was assessed in vitro for its cytotoxicity in the Neutral Red Uptake assay (particle phase and gas/vapor phase separately) in mouse embryo BALB/c 3T3 cells, and for mutagenicity/genotoxicity in the Salmonella typhimurium reverse mutation assay and the mammalian cell mouse lymphoma TK assay in L5178Y cells, the latter with and without metabolic activation. There were some statistically significant differences in the yield of smoke constituents (increases as well as decreases, nearly all of them less than ± 20%) as a result of the addition of the ingredient mixes. However, the addition of the three different mixes of ingredients to the experimental kreteks did not change the in vitro cytotoxicity and mutagenicity/genotoxicity of the smoke, when compared to the control kretek cigarette.

In serum veritas-in serum sanitas? Cell non-autonomous aging compromises differentiation and survival of mesenchymal stromal cells via the oxidative stress pathway.

Even tissues capable of complete regeneration, such as bone, show an age-related reduction in their healing capacity. Here, we hypothesized that this decline is primarily due to cell non-autonomous (extrinsic) aging mediated by the systemic environment. We demonstrate that culture of mesenchymal stromal cells (MSCs) in serum from aged Sprague-Dawley rats negatively affects their survival and differentiation ability. Proteome analysis and further cellular investigations strongly suggest that serum from aged animals not only changes expression of proteins related to mitochondria, unfolded protein binding or involved in stress responses, it also significantly enhances intracellular reactive oxygen species production and leads to the accumulation of oxidatively damaged proteins. Conversely, reduction of oxidative stress levels in vitro markedly improved MSC function. These results were validated in an in vivo model of compromised bone healing, which demonstrated significant increase regeneration in aged animals following oral antioxidant administration. These observations indicate the high impact of extrinsic aging on cellular functions and the process of endogenous (bone) regeneration. Thus, addressing the cell environment by, for example, systemic antioxidant treatment is a promising approach to enhance tissue regeneration and to regain cellular function especially in elderly patients.

CD73/5'-ecto-nucleotidase acts as a regulatory factor in osteo-/chondrogenic differentiation of mechanically stimulated mesenchymal stromal cells.

Bone regeneration is influenced by mesenchymal stromal cells (MSCs) and mechanical conditions. How healing outcome and mechanical stability are linked on the cellular level, however, remains elusive. Cyclic-compressive loading of MSCs affects the expression of molecules involved in angiogenesis and matrix assembly, but also reduces the expression of CD73, an ecto-5'-nucleotidase, which plays a crucial role in extracellular adenosine generation. Although, for almost 20 years, CD73 has been a major cell surface marker defining MSCs, little is known about its function in these cells. Therefore, the aim of this study was to determine the putative involvement of CD73 in MSC differentiation after cyclic-compressive loading. After cultivation in appropriate differentiation media, chondrogenic differentiation ability was significantly increased in loaded MSCs, hence following current models. Through treatment with the CD73 inhibitor adenosine 5'-(α, ß-methylene) diphosphate, chondrogenic matrix deposition was further increased; in contrast, mineral matrix deposition and expression of osteogenic markers was reduced. One major signal transduction pathway, which is activated via CD73-mediated adenosine, is the adenosine receptor pathway. Thus, the adenosine receptor expression pattern was investigated. MSCs expressed the four known adenosine receptors at the mRNA level. After mechanical stimulation of MSCs, Adora2a was down-regulated. These data point towards a role of CD73 in MSC differentiation possibly via A2AR signalling, which is mutually regulated with CD73. In conclusion, the findings of this study suggest that CD73 is another regulatory factor in osteo-/chondrogenic differentiation of MSCs and may provide a - thus far underestimated - therapeutic target to guide bone regeneration.

CD73 and CD29 concurrently mediate the mechanically induced decrease of migratory capacity of mesenchymal stromal cells.

e assumption that mesenchymal stromal cell (MSC)-based-therapies are capable of augmenting physiological regeneration processes has fostered intensive basic and clinical research activities. However, to achieve sustained therapeutic success in vivo, not only the biological, but also the mechanical microenvironment of MSCs during these regeneration processes needs to be taken into account. This is especially important for e.g., bone fracture repair, since MSCs present at the fracture site undergo significant biomechanical stimulation. This study has therefore investigated cellular characteristics and the functional behaviour of MSCs in response to mechanical loading. Our results demonstrated a reduced expression of MSC surface markers CD73 (ecto-5'-nucleotidase) and CD29 (integrin ß1) after loading. On the functional level, loading led to a reduced migration of MSCs. Both effects persisted for a week after the removal of the loading stimulus. Specific inhibition of CD73/CD29 demonstrated their substrate dependent involvement in MSC migration after loading. These results were supported by scanning electron microscopy images and phalloidin staining of actin filaments displaying less cell spreading, lamellipodia formation and actin accumulations. Moreover, focal adhesion kinase and Src-family kinases were identified as candidate downstream targets of CD73/CD29 that might contribute to the mechanically induced decrease in MSC migration. These results suggest that MSC migration is controlled by CD73/CD29, which in turn are regulated by mechanical stimulation of cells. We therefore speculate that MSCs migrate into the fracture site, become mechanically entrapped, and thereby accumulate to fulfil their regenerative functions.

Impact of AIDS on rural livelihoods in Benue State, Nigeria.

This study addresses the socio-economic impact of AIDS on rural livelihoods in Benue State, Nigeria, where HIV prevalence is 9.3% but the number of AIDS cases is still relatively low. About 6% of the study households had experienced illness and death classified as AIDS, and reported high costs in terms of expenditures and time spent on care, funerals and mourning. These demands on time affected income and productivity, while the diversion of resources had implications for investments and savings. Coping strategies varied between households, mainly as a reflection of asset levels, which were often related to the gender of the household head. Reported coping strategies also differed between ethnic groups. First-line relatives were the most important source of support for households under pressure. Erosive coping strategies that undermined the sustainability of livelihoods were used by more vulnerable households following multiple cases of illness and death. Mourning practices, rules of inheritance and stigma tended to increase a household's vulnerability. Currently, Benue State is facing growing adult morbidity and mortality because of HIV infections. A context-specific study of its possible impact in a setting with a still relatively low number of AIDS cases is therefore important for informing local policy development and for building advocacy.

[Results of the follow-up of Ludloff open hip repositions and closed repositions in congenital hip dislocations]. / Nachuntersuchungsergebnisse der offenen Hüftrepositionen nach Ludloff und der geschlossenen Repositionen bei angeborenen Hüftluxationen.

Three combinations of therapy of CDH (closed and open reduction, with and without foregoing so called "functional" conservative treatment, and with and without retention in the frog position) have been evaluated among 82 children with 100 dislocated hips. They had been operated on 71 times by Ludloffs open reduction and 29 times by gentle closed reduction in anaesthesia. If following a test-x-ray in 130 degrees flexion of the hips and 50 degrees of abduction no spontaneous reduction occurs, an attempt at careful closed reduction under anaesthesia seems to be justified. If it is not successful with lack of a deep position of the head, an immediate open reduction after Ludloff with retention in hip flexion of about 130 degrees and slight abduction was in our hands less frequently followed by an avascular necrosis of the femoral head than following conservative treatment. The latter and the inhuman frog position are according to our statistics probably more responsible for the avascular necroses than the open reduction as such. Every treatment of CDH has to be evaluated in regard to the frequency of irreversible avascular necrosis of the femoral head.

[Unilateral knee joint endoprosthesis for treatment of varus or valgus gonarthrosis (indications--technic--late results]. / Die unilaterale Kniegelenksendoprothese zur Behandlung der Varusoder Valgusgonarthrose (Indikation--Technik--Spätergebnisse).

In the treatment of varus- and valgus-gonarthrosis the unilateral joint-replacement has a definite indication. Good longterm results underline the importance of this method amongst all possible and useful procedures.