Long-term results of arthroscopic repair of type II SLAP lesions in sports: assessment of return to pre-injury playing level and critical risk factors for complication

PURPOSE

The management of isolated SLAP lesions is still debated especially in athletes. Aims of the study were: 1. to analyse our algorithm to treat SLAP lesions starting from the selection of patients for surgery and 2. to correlate the familiarity for diabetes and hypothyroid disorders with post-operative results.

METHODS

Seventy-eight patients with isolated SLAP lesion were arthroscopically treated using knotless anchors and microfractures. All patients had a pre-operative and post-operative clinical examination according to Walch-Duplay, Constant, Rowe and Dash scores and interviewed for familiarity to diabetes and hypothyroid disorders.

RESULTS

About 68.8% of patients solved pain with rehabilitation. About 29% of patients returned to the sports activities. About 32% of patients were no responder to physiotherapy and were arthroscopically treated. About 53.9% of patients responded excellent, 34.7% good, 3.8% medium and 7.6% poor results according to Walch-Duplay score. The Constant score increased from 64 to 95, the Rowe score from 48 to 96. The outcomes were significantly worse in patients with familiarity for diabetes.

CONCLUSIONS

Microfractures and knotless anchor give long-term good results for the treatment of SLAP lesions in athletes. The familiarity for diabetes is an important risk factor that can lead to decreased outcomes.

A mid-infrared laser microscope for the time-resolved study of light-induced protein conformational changes

We have developed a confocal laser microscope operating in the mid-infrared range for the study of light-sensitive proteins, such as rhodopsins. The microscope features a co-aligned infrared and visible illumination path for the selective excitation and probing of proteins located in the IR focus only. An external-cavity tunable quantum cascade laser provides a wavelength tuning range (5.80-6.35 µm or 1570-1724 cm-1) suitable for studying protein conformational changes as a function of time delay after visible light excitation with a pulsed LED. Using cryogen-free detectors, the relative changes in the infrared absorption of rhodopsin thin films around 10-4 have been observed with a time resolution down to 30 ms. The measured full-width at half maximum of the Airy disk at λ = 6.08 µm in transmission mode with a confocal arrangement of apertures is 6.6 µm or 1.1λ. Dark-adapted sample replacement at the beginning of each photocycle is then enabled by exchanging the illuminated thin-film location with the microscope mapping stage synchronized to data acquisition and LED excitation and by averaging hundreds of time traces acquired in different nearby locations within a homogeneous film area. We demonstrate that this instrument provides crucial advantages for time-resolved IR studies of rhodopsin thin films with a slow photocycle. Time-resolved studies of inhomogeneous samples may also be possible with the presented instrument.

Antenna-enhanced mid-infrared detection of extracellular vesicles derived from human cancer cell cultures

BACKGROUND

Extracellular Vesicles (EVs) are sub-micrometer lipid-bound particles released by most cell types. They are considered a promising source of cancer biomarkers for liquid biopsy and personalized medicine due to their specific molecular cargo, which provides biochemical information on the state of parent cells. Despite this potential, EVs translation process in the diagnostic practice is still at its birth, and the development of novel medical devices for their detection and characterization is highly required.

RESULTS

In this study, we demonstrate mid-infrared plasmonic nanoantenna arrays designed to detect, in the liquid and dry phase, the specific vibrational absorption signal of EVs simultaneously with the unspecific refractive index sensing signal. For this purpose, EVs are immobilized on the gold nanoantenna surface by immunocapture, allowing us to select specific EV sub-populations and get rid of contaminants. A wet sample-handling technique relying on hydrophobicity contrast enables effortless reflectance measurements with a Fourier-transform infrared (FTIR) spectro-microscope in the wavelength range between 10 and 3 µm. In a proof-of-principle experiment carried out on EVs released from human colorectal adenocarcinoma (CRC) cells, the protein absorption bands (amide-I and amide-II between 5.9 and 6.4 µm) increase sharply within minutes when the EV solution is introduced in the fluidic chamber, indicating sensitivity to the EV proteins. A refractive index sensing curve is simultaneously provided by our sensor in the form of the redshift of a sharp spectral edge at wavelengths around 5 µm, where no vibrational absorption of organic molecules takes place: this permits to extract of the dynamics of EV capture by antibodies from the overall molecular layer deposition dynamics, which is typically measured by commercial surface plasmon resonance sensors. Additionally, the described metasurface is exploited to compare the spectral response of EVs derived from cancer cells with increasing invasiveness and metastatic potential, suggesting that the average secondary structure content in EVs can be correlated with cell malignancy.

CONCLUSIONS

Thanks to the high protein sensitivity and the possibility to work with small sample volumes-two key features for ultrasensitive detection of extracellular vesicles- our lab-on-chip can positively impact the development of novel laboratory medicine methods for the molecular characterization of EVs.

Low-Temperature Stability and Sensing Performance of Mid-Infrared Bloch Surface Waves on a One-Dimensional Photonic Crystal

The growing need for new and reliable surface sensing methods is arousing interest in the electromagnetic excitations of ultrathin films, i.e., to generate electromagnetic field distributions that resonantly interact with the most significant quasi-particles of condensed matter. In such a context, Bloch surface waves turned out to be a valid alternative to surface plasmon polaritons to implement high-sensitivity sensors in the visible spectral range. Only in the last few years, however, has their use been extended to infrared wavelengths, which represent a powerful tool for detecting and recognizing molecular species and crystalline structures. In this work, we demonstrate, by means of high-resolution reflectivity measurements, that a one-dimensional photonic crystal can sustain Bloch surface waves in the infrared spectral range from room temperature down to 10 K. To the best of our knowledge, this is the first demonstration of infrared Bloch surface waves at cryogenic temperatures. Furthermore, by exploiting the enhancement of the surface state and the high brilliance of infrared synchrotron radiation, we demonstrate that the proposed BSW-based sensor has a sensitivity on the order of 2.9 cm^-1 for each nanometer-thick ice layer grown on its surface below 150 K. In conclusion, we believe that Bloch surface wave-based sensors are a valid new class of surface mode-based sensors for applications in materials science.

Spectral Characterization of Mid-Infrared Bloch Surface Waves Excited on a Truncated 1D Photonic Crystal

The many fundamental roto-vibrational resonances of chemical compounds result in strong absorption lines in the mid-infrared region (λ ∼ 2-20 μm). For this reason, mid-infrared spectroscopy plays a key role in label-free sensing, in particular, for chemical recognition, but often lacks the required sensitivity to probe small numbers of molecules. In this work, we propose a vibrational sensing scheme based on Bloch surface waves (BSWs) on 1D photonic crystals to increase the sensitivity of mid-infrared sensors. We report on the design and deposition of CaF₂/ZnS 1D photonic crystals. Moreover, we theoretically and experimentally demonstrate the possibility to sustain narrow σ-polarized BSW modes together with broader π-polarized modes in the range of 3-8 μm by means of a customized Fourier transform infrared spectroscopy setup. The multilayer stacks are deposited directly on CaF₂ prisms, reducing the number of unnecessary interfaces when exciting in the Kretschmann-Raether configuration. Finally, we compare the performance of mid-IR sensors based on surface plasmon polaritons with the BSW-based sensor. The figures of merit found for BSWs in terms of confinement of the electromagnetic field and propagation length puts them as forefrontrunners for label-free and polarization-dependent sensing devices.

Infrared nanospectroscopy study of the light-induced conformational changes of Channelrhodopsin

The channelrhodopsin-ChR2 is a light-sensitive transmembrane protein that acts as a selective ion channel between the intra- and the extra-cellular environments. In the last decade, ChR2 has proven to be essential for optogenetics, because, if expressed in mammalian neural cells, it enables the control of neuronal activity in response to visible light. Mid-infrared difference spectroscopy can probe the functional conformational changes of light-sensitive proteins, however intrinsic limitations of standard IR spectroscopy in terms of diffraction, and therefore number of probed proteins, require that the mid-IR experiments be performed on huge numbers of lipid membrane patches with overexpressed proteins. In this work, we apply for the first time IR difference nanospectroscopy, based on the use of mid-IR lasers and an atomic force microscope (AFM), to single membrane patches containing ChR2, obtaining relevant spectroscopy results for optogenetic applications and, more generally, for future experimental studies of light-sensitive proteins at the nanoscale.

Tip-Enhanced Infrared Difference-Nanospectroscopy of the Proton Pump Activity of Bacteriorhodopsin in Single Purple Membrane Patches

Photosensitive proteins embedded in the cell membrane (about 5 nm thickness) act as photoactivated proton pumps, ion gates, enzymes, or more generally, as initiators of stimuli for the cell activity. They are composed of a protein backbone and a covalently bound cofactor (e.g. the retinal chromophore in bacteriorhodopsin (BR), channelrhodopsin, and other opsins). The light-induced conformational changes of both the cofactor and the protein are at the basis of the physiological functions of photosensitive proteins. Despite the dramatic development of microscopy techniques, investigating conformational changes of proteins at the membrane monolayer level is still a big challenge. Techniques based on atomic force microscopy (AFM) can detect electric currents through protein monolayers and even molecular binding forces in single-protein molecules but not the conformational changes. For the latter, Fourier-transform infrared spectroscopy (FTIR) using difference-spectroscopy mode is typically employed, but it is performed on macroscopic liquid suspensions or thick films containing large amounts of purified photosensitive proteins. In this work, we develop AFM-assisted, tip-enhanced infrared difference-nanospectroscopy to investigate light-induced conformational changes of the bacteriorhodopsin mutant D96N in single submicrometric native purple membrane patches. We obtain a significant improvement compared with the signal-to-noise ratio of standard IR nanospectroscopy techniques by exploiting the field enhancement in the plasmonic nanogap that forms between a gold-coated AFM probe tip and an ultraflat gold surface, as further supported by electromagnetic and thermal simulations. IR difference-spectra in the 1450-1800 cm^-1 range are recorded from individual patches as thin as 10 nm, with a diameter of less than 500 nm, well beyond the diffraction limit for FTIR microspectroscopy. We find clear spectroscopic evidence of a branching of the photocycle for BR molecules in direct contact with the gold surfaces, with equal amounts of proteins either following the standard proton-pump photocycle or being trapped in an intermediate state not directly contributing to light-induced proton transport. Our results are particularly relevant for BR-based optoelectronic and energy-harvesting devices, where BR molecular monolayers are put in contact with metal surfaces, and, more generally, for AFM-based IR spectroscopy studies of conformational changes of proteins embedded in intrinsically heterogeneous native cell membranes.

Adiponectin profile at baseline is correlated to progression and severity of multiple sclerosis

BACKGROUND AND PURPOSE

Adiponectin is a cytokine linking energy metabolism and immune system. After being assembled, adiponectin circulates as oligomers of different molecular weight, i.e. low, medium and high (HMW) molecular weight. These have the most potent biological effects. Multiple sclerosis (MS) is an autoimmune disease of the human central nervous system. The aim of this study was to characterize the expression levels of both total adiponectin and its oligomerization state in the serum from 99 patients with MS at baseline (i.e. not influenced by therapies). We also investigated the potential relationships between adiponectin and disease progression and severity.

METHODS

Adiponectin was quantified and visualized by enzyme-linked immunosorbent assay, western blotting and fast protein liquid chromatography. During the follow-up (3.6 ± 2.20 years), the patients were evaluated using total annualized relapse rate and Expanded Disability Status Scale score.

RESULTS

Total adiponectin is statistically higher in patients with MS compared with matched controls (12.18 vs. 10.02 μg/mL, P = 0.001). Interestingly, the adiponectin oligomerization state is altered in MS, with an increase of HMW oligomers. In addition, patients with MS with higher levels of adiponectin at baseline have significantly higher risk of progression and severity (Multiple Sclerosis Severity Score, 3.84 vs. 2.44, P = 0.001). No statistical difference in adiponectin expression was found between active and inactive patients with MS and among the different forms of disease.

CONCLUSIONS

This study demonstrated that adiponectin and its HMW oligomers are greatly involved in MS autoimmune disorder representing a potential biomarker to predict worse MS prognosis and severity. Further studies are required to clarify the molecular mechanisms underlying the properties of adiponectin and HMW oligomers in MS.

Differentially expressed and activated proteins associated with non small cell lung cancer tissues

Background

Lung cancer is a leading cause of mortality. The most common cancer subtype, non small cell lung cancer (NSCLC), accounts for 85-90 % all cases and is mainly caused by environmental and genetic factors. Mechanisms involved in lung carcinogenesis include deregulation of several kinases and molecular pathways affecting cell proliferation, apoptosis and differentiation. Despite advances in lung cancer detection, diagnosis and staging, survival rate still remains poor and novel biomarkers for both diagnosis and therapy need to be identified. In the present study, we have explored the potential of novel specific biomarkers in the diagnosis of NSCLC, and the over-expression/activation of several kinases involved in disease development and progression.

Method

Lung tumor tissue specimens and adjacent cancer-free tissues from 8 NSCLC patients undergoing surgery were collected. The differential activation status of ERK1/2, AKT and IKBα/NF-κβ was analyzed. Subsequently, protein expression profile of NSCLC vs normal surrounding tissue was compared by a proteomic approach using LC-MS MS. Subsequently, MS/MS outputs were analyzed by the Protein Discoverer platform for label-free quantitation analysis. Finally, results were confirmed by western blotting analysis.

Results

This study confirms the involvement of ERK1/2, AKT, IKBα and NF-κβ proteins in NSCLC demonstrating a significant over-activation of all tested proteins. Furthermore, we found significant differential expression of 20 proteins (R_sc ≥ 1.50 or ≤ −1.50) of which 7 are under-expressed and 13 over-expressed in NSCLC lung tissues. Finally, we validated, by western blotting, the two most under-expressed NSCLC tissue proteins, carbonic anhydrase I and II isoforms.

Conclusion

Our data further support the possibility of developing both diagnostic tests and innovative targeted therapy in NSCLC. In addition to selective inhibitors of ERK1/2, AKT, IKBα and NF-κβ, as therapeutic options, our data, for the first time, indicates carbonic anhydrase I and II as attractive targets for development of diagnostic tools enabling selection of patients for a more specific therapy in NSCLC.

Apparently normal ankyrin content in unsplenectomized hereditary spherocytosis patients with the inactivation of one ankyrin (ANK1) allele

The study of erythrocyte membrane protein concentration by polyacrylamide gel electrophoresis (PAGE) is the first step in approaching the primary molecular defect in hereditary spherocytosis (HS). Normal or greater than normal protein 2.1 levels were found in ten unrelated HS patients showing the inactivation of one ankyrin allele. Erythrocyte membranes from the same patients, once splenectomized, showed a homogeneous degree of protein 2.1 reduction. Thus protein 2.1 levels could misleadingly appear normal due to the high number of circulating reticulocytes. To calculate the true ankyrin level using PAGE and consequently to avoid mistakes in studying a mutated gene, a simple equation, based on the number of reticulocytes, was developed.

Serologic response to treatment of syphilis in patients with HIV infection

BACKGROUND

Much controversy exists concerning the manifestations, therapy, and response to treatment of syphilis in patients coinfected with the human immunodeficiency virus (HIV).

OBJECTIVE

To assess the effect of HIV infection on the serologic response to treatment of patients with syphilis.

METHODS

Sixty-four HIV-seropositive patients with syphilis were matched with 64 patients with syphilis who were HIV negative. Matching criteria included age (+/- 5 years), sex, race, initial rapid plasma reagin (RPR) titer (+/- 1 dilution), and stage of syphilis at entry. There were 26 matched patients with early syphilis, 26 matched patients with late syphilis, and 12 matched patients with biological false-positive RPR. The HIV-positive patients with early syphilis received three doses of penicillin G benzathine. All other patients received treatment as recommended by the Centers for Disease Control and Prevention, Atlanta, Ga. Our study's major end points were clinical and serologic response to treatment.

RESULTS

All 16 patients with symptomatic syphilis were cured. No patient developed clinical signs of neurosyphilis during the 12-month follow-up period. Twenty-nine (56%) of 52 HIV-positive patients with early or late syphilis did not have a fourfold decrease in RPR titer 6 months after treatment compared with 20 (38%) of 52 matched controls (P = .06). No unique characteristics identifying patients who did not respond serologically could be established. The HIV-positive patients with initial RPR less than 1:32 experienced a significantly slower decrease in RPR at 12 months than did the controls (P < .001).

CONCLUSIONS

Patients with syphilis who are HIV positive are less likely to experience serologic improvement after recommended therapy than are patients with syphilis who are HIV negative. Patients with HIV infection who contract syphilis should receive intensive and prolonged follow-up, and consideration should be given to designing alternative regimens.

Initial management of serious urinary tract infection: epidemiologic guidelines

OBJECTIVE

To obtain information necessary for the development of initial antibiotic treatment guidelines for patients with serious urinary tract infections.

DESIGN

Retrospective chart review.

SETTING

The medical service of a 533-bed university-affiliated community hospital.

PATIENTS

253 unselected patients hospitalized between January 1985 and December 1987 given principal discharge diagnoses of urinary tract infection, pyelonephritis, or gram-negative rod bacteremia originating in the urinary tract.

RESULTS

Three clinically distinct groups were identified: women under 50 years old, older women, and men. Escherichia coli was isolated from 93% of young women, 70% of older women, and 46% of men. Pseudomonas aeruginosa was isolated from 39% of men with one or more urinary tract risk factors, including recent or recurrent urinary tract infections and known genitourinary tract abnormality. The overall prevalence of Group D streptococci was only 1%. More than 20% of the patients in each group were bacteremic. In all groups, resistance to ampicillin and first-generation cephalosporins was common. Trimethoprim-sulfamethoxazole was active in 98% of young women and 85% of older women and men without urinary risk factors.

CONCLUSIONS

Age and gender identify clinically important subgroups of patients with serious urinary tract infections. Pending culture results, all patients should be considered bacteremic, ampicillin alone should not be prescribed, and antibiotics effective against P. aeruginosa should be given to men, especially those with risk factors.