Co-loading of bisphosphonates and antibiotics to a biomimetic hydroxyapatite coating

We have incorporated bisphosphonates and antibiotics simultaneously into a biomimetic hydroxyapatite implant coating aiming to use the interaction between drug-molecules and hydroxyapatite to enable local release of the two different substances to obtain a dual biological effect. A sustained release over for 43 h of antibiotics (cephalothin) was achieved without negative interference from the presence of the bisphosphonate (clodronate) which, in turn, successfully bonded to the coating surface. To our knowledge, this is the first study that indicates the possibility to simultaneously incorporate both antibiotics and bisphosphonates to an implant coating, a strategy that is believed to improve implant stability and reduce implant-related infections.     

α-synuclein reactive antibodies as diagnostic biomarkers in blood sera of Parkinson's disease patients

Background

Auto-antibodies with specificity to self-antigens have been implicated in a wide variety of neurological diseases, including Parkinson''s (PD) and Alzheimer''s diseases, being sensitive indicators of neurodegeneration and focus for disease prevention. Of particular interest are the studies focused on the auto-immune responses to amyloidogenic proteins associated with diseases and their applications in therapeutic treatments such as vaccination with amyloid antigens and antibodies in PD, Alzheimer''s disease and potentially other neurodegeneration ailments.

Methodology/Principal Findings

Generated auto-antibodies towards the major amyloidogenic protein involved in PD Lewy bodies – α-synuclein and its amyloid oligomers and fibrils were measured in the blood sera of early and late PD patients and controls by using ELISA, Western blot and Biacore surface plasmon resonance. We found significantly higher antibody levels towards monomeric α-synuclein in the blood sera of PD patients compared to controls, though the responses decreased with PD progression (P<0.0001). This indicates potential protective role of autoimmunity in maintaining the body homeostasis and clearing protein species whose disbalance may lead to amyloid assembly. There were no noticeable immune responses towards amyloid oligomers, but substantially increased levels of IgGs towards α-synuclein amyloid fibrils both in PD patients and controls, which subsided with the disease progression (P<0.0001). Pooled IgGs from PD patients and controls interacted also with the amyloid fibrils of Aβ (1–40) and hen lysozyme, however the latter were recognized with lower affinity. This suggests that IgGs bind to the generic amyloid conformational epitope, displaying higher specificity towards human amyloid species associated with neurodegeneration.

Conclusions/Significance

Our findings may suggest the protective role of autoimmunity in PD and therefore immune reactions towards PD major amyloid protein – α-synuclein can be of value in the development of treatment and diagnostic strategies, especially during the early disease stages.     

Large males fight and court more across a range of social environments: an experiment on the two spotted goby Gobiusculus flavescens

The present study explored how male size relates to mating competition across a natural range of male and female densities in the two-spotted goby Gobiusculus flavescens. Across this range of social environments, large males were more than twice as likely as small ones to chase other males, to become nest-holders, and to court females, but large males were not significantly more likely to engage in agonistic fin displays. Overall, the study showed that large males court and fight more than small ones across a wide, yet natural, span of social environments. Having a large body size appears to confer competitive advantage for males in any social environment of the study species. Further studies are needed to disentangle whether the benefit of large size is mainly in competition over resources, over matings as such, or both.     

Immunohistochemical procedures for the demonstration of peptide- and tyrosine hydroxylase-containing nerve fibers in cryostat sections of unfixed rapidly frozen tissue stored for long periods of time. A study on heart tissue

Traditional protocols for the immunohistochemical localization of peptides and tyrosine hydroxylase (TH) in nerve fibers in cryostat sections require the tissue to be thoroughly fixed and rinsed and to be processed for the cryostat sectioning and the immunohistochemical staining more or less directly after freezing. In the present study it was tested whether also unfixed, rapidly frozen tissue, conforming to guinea pig and bovine heart specimens, can be used for the visualization of neuropeptides [neuropeptide Y (NPY) and substance P (S P)] and TH in cryostat sections. The following observations were made: 1) NPY-immunoreactive (IR) and S P-IR nerve fibers could be clearly identified in both fixed and unfixed sections of this type of tissue. 2) TH-IR nerve fibers could be detected in unfixed tissue if the sections were post-fixed with aldehydes by the use of a two-step fixation process related to a sudden change of pH. However, the outlines of the nerve fibers were sometimes diffuse. 3) Storage of unfixed tissue for periods of up to 2.5 years at-80 degrees C did not lead to a decrease in immunoreactivity. 4) Somewhat higher concentrations of primary antibodies had to be used for sections of unfixed tissue than for sections of fixed tissue when the FITC method was used. This waste of antibodies was partly overcome by use of the biotin-streptavidin method. The glyoxylic acid induced catecholamine(CA)-fluorescence method for demonstration of sympathetic nerve fibers was also applied and was found to give optimal results after storage of tissue for up to 2.5 years.(ABSTRACT TRUNCATED AT 250 WORDS)     

Myocardial cell heterogeneity in the human heart with respect to myosin ATPase activity

Summary The pH sensitivity of the Ca²⁺-activated myosin ATPase in atrial, ventricular and conduction tissue of human hearts has been established. Heterogeneity with respect to ATPase activity is shown not only to exist between the atrial, the ventricular myocardium and the conduction system but alsowithin both the ordinary atrial and ventricular myocardium andwithin the conduction system. These observations are related to the polymorphism of the myosin molecule and suggest that fibre types with different contractile properties co-exist in the human heart.     

Presence of substance P and the neurokinin-1 receptor in tenocytes of the human Achilles tendon

Nerve signal substances, such as the tachykinin substance P (SP), may be involved in the changes that occur in response to tendinopathy (tendinosis). It is previously known that the level of SP innervation within tendon tissue is limited, but results of experimental studies have suggested that SP may have stimulatory, angiogenetic and healing effects in injured tendons. Therefore, it would be of interest to know if there is a local SP-supply in tendon tissue. In the present study, the patterns of expression of SP and its preferred receptor, the neurokinin-1 receptor (NK-1 R), in normal and tendinosis human Achilles tendons were analyzed by use of both immunohistochemistry and in situ hybridization. We found that there was expression of SP mRNA in tenocytes, and that tenocytes showed expression of NK-1 R at protein as well as mRNA levels. The observations concerning both SP and NK-1 R were most evident for tenocytes in tendinosis tendons. Our findings suggest that SP is produced in tendinosis tendons, and furthermore that SP has marked effects on the tenocytes via the NK-1 R. It cannot be excluded that the SP effects are of importance concerning the processes of reorganization and healing that occur for tendon tissue in tendinosis. In conclusion, it appears as if SPergic autocrine/paracrine effects occur in tendon tissue during the processes of tendinosis, hitherto unknown effects for human tendons.     

Heteroplasmy of the human mtDNA control region remains constant during life

In a longitudinal, retrospective study, we monitored the level of heteroplasmy at nucleotide position (nt) 309 and nt 16189 of the control region of human mtDNA. As a unique source of DNA, we analyzed multiple cervical-cell samples collected, during 1 or 2 decades, from four women with heteroplasmy at either nt 309 or nt 16189. According to accurate, quantitative analysis by solid-phase minisequencing, the level of heteroplasmy remained stable in the cervical-cell samples from all four women during the time studied. We also analyzed autopsy samples from several different tissues, all containing nt 309 in heteroplasmic form, of one of the women, who was deceased. On the basis of our results, heteroplasmy in the control region of mtDNA seems to be inherited and is not the result of somatic age-related accumulation.