Diffusion and Protein Corona Formation of Lipid-Based Nanoparticles in the Vitreous Humor: Profiling and Pharmacokinetic Considerations

The vitreous humor is the first barrier encountered by intravitreally injected nanoparticles. Lipid-based nanoparticles in the vitreous are studied by evaluating their diffusion with single-particle tracking technology and by characterizing their protein coronae with surface plasmon resonance and high-resolution proteomics. Single-particle tracking results indicate that the vitreal mobility of the formulations is dependent on their charge. Anionic and neutral formulations are mobile, whereas larger (>200 nm) neutral particles have restricted diffusion, and cationic particles are immobilized in the vitreous. PEGylation increases the mobility of cationic and larger neutral formulations but does not affect anionic and smaller neutral particles. Convection has a significant role in the pharmacokinetics of nanoparticles, whereas diffusion drives the transport of antibodies. Surface plasmon resonance studies determine that the vitreal corona of anionic formulations is sparse. Proteomics data reveals 76 differentially abundant proteins, whose enrichment is specific to either the hard or the soft corona. PEGylation does not affect protein enrichment. This suggests that protein-specific rather than formulation-specific factors are drivers of protein adsorption on nanoparticles in the vitreous. In summary, our findings contribute to understanding the pharmacokinetics of nanoparticles in the vitreous and help advance the development of nanoparticle-based treatments for eye diseases.

Landscape history improves detection of marginal habitats on semi-natural grasslands

Semi-natural grassland habitats have markedly declined from their historical coverage, thus causing substantial losses for agricultural biodiversity and establishing a consequent need to spot the remaining habitat patches. These patches are generally remnants of once larger habitat areas, formed by uninterrupted and low-intensity management for centuries, but then later being isolated and fragmented into smaller pieces. In the light of this development, past landscape phases have a crucial role for the present existence of semi-natural grasslands. The importance of historical factors has been indicated in many studies but evaluation of their added value, or actual site-specific effects compared to observations of only the present landscape characteristics, is not generally provided. As data related to the past is often difficult to obtain, tedious to process and challenging to interpret, assessment of its advantages and related effects - or consequences of potential exclusion - would be needed. In this study, we used maximum entropy approach to model the distribution of Fumewort (Corydalis solida) which in the study area is a good indicator of valuable semi-natural habitats. We constructed three different models - one based on only the contemporary environment with expected indicators of habitat stability, one solely on the historical landscape phases and long-term dynamics, and one combining variables from the past and the present. Predictions of the three models were validated and compared with each other, followed by an analysis indicating the similarity of model results with known Fumewort occurrences. Our results indicate that present landscapes may provide workable surrogates to delineate larger core habitats, but utilization of historical data markedly improves the detection of small outlying patches. These conclusions emphasize the importance of previous landscape phases particularly in detecting marginal semi-natural grassland habitats, existing in contemporarily suboptimal conditions and being prone to disappear if no further actions are taken.

Treatment of non-traumatic rotator cuff tears: A randomised controlled trial with one-year clinical results

We have compared three different methods of treating symptomatic non-traumatic tears of the supraspinatus tendon in patients above 55 years of age. A total of 180 shoulders (173 patients) with supraspinatus tendon tears were randomly allocated into one of three groups (each of 60 shoulders); physiotherapy (group 1), acromioplasty and physiotherapy (group 2) and rotator cuff repair, acromioplasty and physiotherapy (group 3). The Constant score was assessed and followed up by an independent observer pre-operatively and at three, six and twelve months after the intervention. Of these, 167 shoulders were available for assessment at one year (follow-up rate of 92.8%). There were 55 shoulders in group 1 (24 in males and 31 in females, mean age 65 years (55 to 79)), 57 in group 2 (29 male and 28 female, mean age 65 years (55 to 79)) and 55 shoulders in group 3 (26 male and 29 female, mean age 65 years (55 to 81)). There were no between-group differences in the Constant score at final follow-up: 74.1 (sd 14.2), 77.2 (sd 13.0) and 77.9 (sd 12.1) in groups 1, 2 and 3, respectively (p = 0.34). The mean change in the Constant score was 17.0, 17.5, and 19.8, respectively (p = 0.34). These results suggest that at one-year follow-up, operative treatment is no better than conservative treatment with regard to non-traumatic supraspinatus tears, and that conservative treatment should be considered as the primary method of treatment for this condition.

Non-labeled monitoring of targeted liposome interactions with a model receptor surface: effect of flow rate and water content

In this study, we present a novel in vitro approach that utilizes two surface-sensitive and label-free techniques, i.e. surface plasmon resonance (SPR) and quartz crystal microbalance (QCM), to study the interfacial events during liposome-target surface interactions. The flow channels of SPR and QCM devices were first synchronized via hydrodynamic modeling. Biotin-streptavidin was used as a model pair and self-assembled monolayers (SAMs) were utilized as model surfaces for targeted liposome-surface interaction studies. The interactions between biotin-liposomes and the streptavidin-biotin-SAM surfaces were investigated under controlled shear flows using the synchronized SPR and QCM devices. The response of the liposome interaction was monitored as a function of the flow rate. The affinity and the amount of bound liposome indicated that the increased flow rate improved the binding of the targeted liposomes to the model membrane surfaces. The combined use of the synchronized SPR and QCM devices for nanoparticle interaction studies clearly demonstrates the effect of the flow rate (or the shear stress) on the liposome binding. Our results suggest that the binding of liposomes to the model membranes is flow rate and shear stress regulated. Thus, the flow rate (or the shear stress), which is usually neglected, should be taken into account during the development and optimization of targeted liposome formulations. In addition, the water content within the liposome layer (including the water inside the liposomes and the water between the liposomes) had a significant influence on the visco-elasticity and the binding kinetics to the SAM surfaces.

No evidence of long-term benefits of arthroscopicacromioplasty in the treatment of shoulder impingement syndrome: Five-year results of a randomised controlled trial

Objectives

To report the five-year results of a randomised controlled trial examining the effectiveness of arthroscopic acromioplasty in the treatment of stage II shoulder impingement syndrome.

Methods

A total of 140 patients were randomly divided into two groups: 1) supervised exercise programme (n = 70, exercise group); and 2) arthroscopic acromioplasty followed by a similar exercise programme (n = 70, combined treatment group).

Results

The main outcome measure was self-reported pain as measured on a visual analogue scale. At the five-year assessment a total of 109 patients were examined (52 in the exercise group and 57 in the combined treatment group). There was a significant decrease in mean self-reported pain on the VAS between baseline and the five-year follow-up in both the exercise group (from 6.5 (1 to 10) to 2.2 (0 to 8); p < 0.001) and the combined treatment group (from 6.4 (2 to 10) to 1.9 (0 to 8); p < 0.001). The same trend was seen in the secondary outcome measures (disability, working ability, pain at night, Shoulder Disability Questionnaire and reported painful days). An intention-to-treat analysis showed statistically significant improvements in both groups at five years compared with baseline. Further, improvement continued between the two- and five-year timepoints. No statistically significant differences were found in the patient-centred primary and secondary parameters between the two treatment groups.

Conclusions

Differences in the patient-centred primary and secondary parameters between the two treatment groups were not statistically significant, suggesting that acromioplasty is not cost-effective. Structured exercise treatment seems to be the treatment of choice for shoulder impingement syndrome.

Cultural and climatic changes shape the evolutionary history of the Uralic languages

Quantitative phylogenetic methods have been used to study the evolutionary relationships and divergence times of biological species, and recently, these have also been applied to linguistic data to elucidate the evolutionary history of language families. In biology, the factors driving macroevolutionary processes are assumed to be either mainly biotic (the Red Queen model) or mainly abiotic (the Court Jester model) or a combination of both. The applicability of these models is assumed to depend on the temporal and spatial scale observed as biotic factors act on species divergence faster and in smaller spatial scale than the abiotic factors. Here, we used the Uralic language family to investigate whether both 'biotic' interactions (i.e. cultural interactions) and abiotic changes (i.e. climatic fluctuations) are also connected to language diversification. We estimated the times of divergence using Bayesian phylogenetics with a relaxed-clock method and related our results to climatic, historical and archaeological information. Our timing results paralleled the previous linguistic studies but suggested a later divergence of Finno-Ugric, Finnic and Saami languages. Some of the divergences co-occurred with climatic fluctuation and some with cultural interaction and migrations of populations. Thus, we suggest that both 'biotic' and abiotic factors contribute either directly or indirectly to the diversification of languages and that both models can be applied when studying language evolution.

Determination of odorous VOCs and the risk of occupational exposure to airborne compounds at the waste water treatment plants

Concentrations of non methane-VOCs and risk levels of employees' exposure to VOCs were determined at two Finnish waste water treatment plants. The concentration of hydrogen sulphide (H2S) reached the Finnish OEL (occupational exposure limit). The concentrations of styrene, 1,2-dichloroethane, and toluene were found to be elevated at plant A. 328.4 microg/m3 of styrene and 709.8 microg/m3 toluene was found in the sludge dewatering, and 955.8 microg/m3 of 1,2-dichloroethane was detected in the trash rake. TVOC concentrations varied from 149.8 microg/m3 in the Plant B sludge dewatering to 7719.0 microg/m3 in the Plant A sludge dewatering. Most of the detected TVOC concentrations were quite high in comparison to the indoor air regulations or recommendations. The most odorous compounds were determined by combined TD-GC-MS-sniffing analysis. Odour was mainly caused by sulphur-containing compounds, aldehydes, and butanoic acid, in addition to aromatic compounds such as styrene, toluene and 4-methylphenol.

Does arthroscopic acromioplasty provide any additional value in the treatment of shoulder impingement syndrome?: a two-year randomised controlled trial

We report a randomised controlled trial to examine the effectiveness and cost-effectiveness of arthroscopic acromioplasty in the treatment of stage II shoulder impingement syndrome. A total of 140 patients were randomly divided into two treatment groups: supervised exercise programme (n = 70, exercise group) and arthroscopic acromioplasty followed by a similar exercise programme (n = 70, combined treatment group). The main outcome measure was self-reported pain on a visual analogue scale of 0 to 10 at 24 months, measured on the 134 patients (66 in the exercise group and 68 in the combined treatment group) for whom endpoint data were available. An intention-to-treat analysis disclosed an improvement in both groups but without statistically significant difference in outcome between the groups (p = 0.65). The combined treatment was considerably more costly. Arthroscopic acromioplasty provides no clinically important effects over a structured and supervised exercise programme alone in terms of subjective outcome or cost-effectiveness when measured at 24 months. Structured exercise treatment should be the basis for treatment of shoulder impingement syndrome, with operative treatment offered judiciously until its true merit is proven.

Design of an air sampler for a small unmanned aerial vehicle

In the aftermath of a nuclear accident or malevolent act, it is of paramount importance to have the capability to monitor airborne radioactive substances by collecting air samples. For potentially dangerous missions, the Radiation and Nuclear Safety Authority of Finland (STUK) has developed an air sampler to be used on a small unmanned aerial vehicle. When a Petrianov or Fluoropore filter is used in the sampler and the air velocity is 71 km h(-1), the air flow rate through the filter is 0.73 m(3) h(-1) or 0.23 m(3) h(-1), respectively. The present article introduces the developed air sampler using fluid dynamic simulations and wind tunnel data. The operation of the system was validated by collecting airborne radioactive aerosols from air.

Glycosaminoglycan-resistant and pH-sensitive lipid-coated DNA complexes produced by detergent removal method

Cationic polymers are efficient gene delivery vectors in in vitro conditions, but these carriers can fail in vivo due to interactions with extracellular polyanions, i.e. glycosaminoglycans (GAG). The aim of this study was to develop a stable gene delivery vector that is activated at the acidic endosomal pH. Cationic DNA/PEI complexes were coated by 1,2-dioleylphosphatidylethanolamine (DOPE) and cholesteryl hemisuccinate (CHEMS) (3:2 mol/mol) using two coating methods: detergent removal and mixing with liposomes prepared by ethanol injection. Only detergent removal produced lipid-coated DNA complexes that were stable against GAGs, but were membrane active at low pH towards endosome mimicking liposomes. In relation to the low cellular uptake of the coated complexes, their transfection efficacy was relatively high. PEGylation of the coated complexes increased their cellular uptake but reduced the pH-sensitivity. Detergent removal was thus a superior method for the production of stable, but acid activatable, lipid-coated DNA complexes.

Precisely defined protein-polymer conjugates: construction of synthetic DNA binding domains on proteins by using multivalent dendrons

Nature has evolved proteins and enzymes to carry out a wide range of sophisticated tasks. Proteins modified with functional polymers possess many desirable physical and chemical properties and have applications in nanobiotechnology. Here we describe multivalent Newkome-type polyamine dendrons that function as synthetic DNA binding domains, which can be conjugated with proteins. These polyamine dendrons employ naturally occurring spermine surface groups to bind DNA with high affinity and are attached onto protein surfaces in a site-specific manner to yield well-defined one-to-one protein-polymer conjugates, where the number of dendrons and their attachment site on the protein surface are precisely known. This precise structure is achieved by using N-maleimido-core dendrons that selectively react via 1,4-conjugate addition with a single free thiol group on the protein surface--either Cys-34 of bovine serum albumin (BSA) or a genetically engineered cysteine mutant of Class II hydrophobin (HFBI). This reaction can be conducted in mild aqueous solutions (pH 7.2-7.4) and at ambient temperature, resulting in BSA- and HFBI-dendron conjugates. The protein-dendron conjugates constitute a specific biosynthetic diblock copolymer and bind DNA with high affinity, as shown by ethidium bromide displacement assay. Importantly, even the low-molecular-weight first-generation polyamine dendron (1 kDa) can bind a large BSA protein (66.4 kDa) to DNA with relatively good affinity. Preliminary gene transfection, cytotoxicity, and self-assembly studies establish the relevance of this methodology for in vitro applications, such as gene therapy and surface patterning. These results encourage further developments in protein-dendron block copolymer-like conjugates and will allow the advance of functional biomimetic nanoscale materials.

When does subluxation of the first carpometacarpal joint cause swan-neck deformity of the thumb in rheumatoid arthritis: a 20-year follow-up study

The aim of our study was to assess the incidence of subluxation of the first carpometacarpal joint (CMC I) and to evaluate which degree of subluxation produces swan-neck deformity of the thumb in rheumatoid arthritis (RA) occurring over 20 years. The hands of 83 rheumatoid factor (RF)-positive RA patients with recent (< or = 6 months) arthritis were evaluated radiographically at onset and at 1, 3, 8 and 15 years; 68 patients were evaluated at 20 years from entry. Subluxation was assessed in millimetres and compared with the MCP-I angle measurement to evaluate the thumb deformity. A statistical end-point analysis was performed between two different grades of subluxation. Subluxation of 2-3 mm was non-specific and only one third of these thumbs showed swan-neck deformity. At the end-point, subluxation of > or = 4mm was present in 17% of the thumbs, 81% of which had the swan-neck deformity; only five thumbs did not show this deformity, but presented deformed and unstable MCP I and interphalangeal joints. The frequency of swan-neck deformity was highly significantly (p < 0.0001) increased in the thumbs with severe CMC I subluxation (> or = 4 mm) compared with lesser subluxation (< 4 mm). When subluxation of the CMC I exceeds 4 mm, the swan-neck deformity of the thumb is a common consequence. This deformity is often progressive, and the hand function of such patients should be followed up carefully, both clinically and radiographically.

Natural history of peripheral neuropathy in patients with non-insulin-dependent diabetes mellitus

BACKGROUND

There is little information on the incidence and natural history of neuropathy in patients with non-insulin-dependent diabetes mellitus (NIDDM).

METHODS

We studied patients with newly diagnosed NIDDM and control subjects both at base line and 5 and 10 years later. Polyneuropathy was diagnosed on the basis of clinical criteria (pain and paresthesias) and electrodiagnostic studies (nerve conduction velocity and response-amplitude values). We investigated the relation between metabolic variables (results of oral glucose-tolerance tests, serum lipid and insulin concentrations, and glycosylated hemoglobin values) and the development of polyneuropathy.

RESULTS

In 10 years, 36 patients with NIDDM and 8 control subjects died; 86 patients and 121 control subjects completed the study. When the study ended, 18 percent of the patients were being treated only with diet, 59 percent with oral hypoglycemic drugs alone, 12 percent with insulin alone, and 11 percent with both insulin and oral hypoglycemic agents. At base line the prevalence of definite or probable polyneuropathy among the patients with NIDDM was 8.3 percent, as compared with 2.1 percent among the control subjects. These values 10 years later were 41.9 percent and 5.8 percent, respectively. The number of patients with NIDDM who had nerve-conduction abnormalities in the legs and feet increased from 8.3 percent at base line to 16.7 percent after 5 years and to 41.9 percent after 10 years. The decrease in sensory and motor amplitudes, indicating axonal destruction, was more pronounced than the slowing of the nerve conduction velocities, which indicates demyelination. Among the patients with NIDDM, those with polyneuropathy had poorer glycemic control than those without. Low serum insulin concentrations before and after the oral administration of glucose were associated with the development of polyneuropathy, regardless of the degree of glycemia.

CONCLUSIONS

The prevalence of polyneuropathy among patients with NIDDM increases with time, and the increase may be greater in patients with hypoinsulinemia.

A prospective study of clinical and metabolic associates of proteinuria in patients with type 2 diabetes mellitus

Urinary protein excretion rate and clinical and metabolic associates were investigated in a group of 108 patients with Type 2 diabetes mellitus at the time of diagnosis and after 5 years, and also 121 control subjects. The presence of coronary heart disease, neuropathy and retinopathy, cardiovascular risk factors and 24-h urinary excretion rate of albumin, beta-2-microglobulin, and IgG were examined. At the 5-year examination, urinary excretion rate of albumin was higher in diabetic patients than in control subjects (39 +/- 75 vs 16 +/- 28 mg 24 h-1 for men, p < 0.05; 38 +/- 57 vs 22 +/- 42 mg 24(-1) h for women, p < 0.01). Furthermore, increased beta-2-microglobulin excretion rate, a marker of tubular impairment, was observed in diabetic men as compared to control men (0.17 +/- 0.15 vs 0.14 +/- 0.21 mg 24 h-1, p < 0.05). Diabetic patients with increased albumin excretion rate (> 30 mg 24 h-1) showed poorer metabolic control than those with normal albumin excretion rate, but no significant differences in body mass index or in the frequencies of smoking, hypertension, coronary heart disease or retinopathy and neuropathy were observed between the groups. Baseline hyperinsulinaemia was closely associated with increasing albuminuria at the 5-year examination.

Increased serum placental-like alkaline phosphatase activity in smokers originates from the lungs

To study the origin of increased serum placental-like alkaline phosphatase (PLAP-like) activity in smokers, heat stable alkaline phosphatase activity was assayed from serum and bronchoalveolar lavage (BAL) fluid in 83 smoking and non-smoking patients. PLAP-like activity was increased in about 80% of the smokers, independently of the underlying lung disease. Isoenzyme activities in BAL fluid correlated (r = 0.631, p less than 0.001) with serum values. When adjusted for the albumin concentration, mean PLAP-like activity in BAL fluid was almost 1000-fold higher than that in serum, suggesting local synthesis of PLAP-like isoenzymes in the lungs. Although a direct dose-response effect was not observed, the values in serum and in BAL fluid tended to be higher in patients smoking over 10 cigarettes daily as compared to patients smoking less. In ex-smokers the results indicated that PLAP-like activity decreased to the level observed in non-smokers within 5 years after cessation of smoking. PLAP activity was L-leucine sensitive compatible with the Nagao-variant type of PLAP in almost all cases. In three patients the activity was due to the L-leucine resistant (true placental) isoenzyme.

Causes of death in institutionalized epileptics

To assess the causes of death in institutionalized epileptics, the patient records, death certificates, and other data from the only hospital for epileptics in Finland (Vaajasalo Hospital) were reexamined. During the years 1900--1976, 179 inpatients in Vaajasalo Hospital died; this was 12% of all inpatients. The most common causes of death were as follows: pneumonia in 40 cases, seizures in 34 cases (single seizure in 18 and status epileptics in 16), drowning in 29 cases, stroke in 10 cases, and heart infarct in 9 cases. Chronic intoxication caused by phenytoin and/or phenobarbitol was a common supplementary factor leading to death in patients who died of pneumonia or seizures. Thirteen deaths were recorded as suicides or suspected suicides (11 by drowning and 2 by strangulation). The results reflect the severe epilepsy and the poor conditions of the patients, as well as the poor condition of the local facilities in the past. The information obtained should be useful in the effort to improve medical care for these patients.

The effect of ICI 74,917 on asthma and bronchial provocation tests

A study was made of the protective action of the anti-allergic drug ICI 74,917, a phenanthroline derivative, in specific allergen provocation tests and in combating clinical symptoms in thirteen asthmatic out-patients. It was found that ICI 74,917 was able to diminish allergen-induced bronchoconstriction significantly (P less than 0.01) during both the placebo period and during chronic treatment with ICI 74,917 for 4 weeks. The results obtained during these two periods did not differ significantly. There was not, however, any statistically significant difference in the symptom scores or PEF rates during the treatment with ICI 74,917 or placebo for 1 month. This may indicate that although ICI 74,197 is able to prevent bronchoconstriction in an allergen provocation test, it failed to improve asthma clinically. No signs of the phenomenon of tachyphylaxis were observed in the present study. The Student's t-test was used in the statistical analysis.