Chronic PCSK9 inhibitor therapy leads to sustained improvements in endothelial function, arterial stiffness, and microvascular function.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) effectively decrease low-density lipoprotein cholesterol (LDL-C) and reduce cardiovascular events in patients at very high cardiovascular risk. Recent short-term studies suggest a partially LDL-C independent beneficial effect of PCSK9 inhibitor (PCSK9i) therapy on endothelial function and arterial stiffness, whereas it is unknown if this effect persists and what the effect is on microcirculation. OBJECTIVE: To investigate the effects of PCSK9i therapy on vascular parameters beyond its lipid lowering effect. METHODS: In this prospective trial, 32 patients at very high cardiovascular risk and indication for PCSK9i therapy were included. Measurements were performed at baseline and after 6 months of PCSK9i treatment. Endothelial function was assessed as flow-mediated dilation (FMD). Arterial stiffness was measured as pulse wave velocity (PWV) and aortic augmentation index (AIx). Peripheral tissue oxygenation (StO2) as a marker of microvascular function was assessed at the distal extremities using near-infrared spectroscopy camera. RESULTS: Six months of PCSK9i therapy decreased LDL-C levels from 141 ± 54 to 60 ± 30 mg/dl (-56 ± 21 %, p < 0.001), FMD significantly increased from 5.4 ± 1.7 % to 6.4 ± 1.9 % (+19 ± 10 %, p < 0.001), PWV decreased in male patients significantly from 8.9 ± 2.1 to 7.9 ± 1.5 m/s (-12 ± 9 %, p = 0.025). AIx decreased from 27.1 ± 10.4 % to 23.0 ± 9.7 % (-16 ± 14 %, p < 0.001), StO2 significantly increased from 67 ± 12 % to 71 ± 11 % (+7 ± 6 %, p = 0.012). Brachial and aortic blood pressure showed no significant changes after six months. There was no correlation between LDL-C reduction and changes in vascular parameters. CONCLUSIONS: Chronic PCSK9i therapy is associated with sustained improvements in endothelial function, arterial stiffness, and microvascular function independent from lipid lowering.

Microvascular tissue perfusion after postcatheterization pseudoaneurysm treatment.

BACKGROUND: Femoral pseudoaneurysm (PSA) is a severe complication after endovascular procedures. Ultrasound-guided manual compression (MC) and percutaneous thrombin injection (TI) are frequently used treatments. MC is less effective, TI may cause thromboembolic events. OBJECTIVE: Up to date, there is no data regarding impairment of microvascular tissue perfusion after PSA treatment. METHODS: In this single-center, prospective study 22 patients with PSA were included. We compared macro- and microcirculatory perfusion in the treated and untreated leg at baseline before, after and one day after treatment. Leg perfusion was assessed with ultrasound and ankle-brachial index (ABI). Microcirculatory perfusion of the feet was measured with a near-infrared spectroscopy (NIRS) camera generating StO2-tissue-maps. RESULTS: Successful PSA thrombosis was achieved in 16 (100%) patients in TI group and in 4 (66.7%) patients in MC group. There was no evidence of arterial thrombi on ultrasound and the ABI did not differ between groups. NIRS StO2-tissue-maps of the feet showed no significant difference in both groups concerning the treated (p = 0.121) or the untreated (p = 0.198) leg during follow up. CONCLUSIONS: In this small exploratory study, there was no evidence of micro- and macrovascular tissue perfusion impairment after treatment of postcatheterization femoral pseudoaneurysm with thrombin injection underscoring the safety of this approach.

Wavelength, dose, skin type and skin model related radical formation in skin.

The exposure to sun radiation is indispensable to our health; however, a long-term and high exposure could lead to cell damage, erythema, premature skin aging, and promotion of skin tumors. An underlying pathomechanism is the formation of free radicals which may induce oxidative stress at elevated concentrations. Different skin models, such as porcine-, murine-, human- ex vivo skin, reconstructed human skin (RHS) and human skin in vivo, were investigated during and after irradiation using X- and L-band EPR spectroscopy within different spectral regions (UVC to NIR). The amount of radical formation was quantified with the spin probe PCA and the radical types were measured ex vivo with the spin trap DMPO. The radiation dose influences the types of radicals formed in the skin. While reactive oxygen species (ROS) are always pronounced at low doses, there is an increase in lipid oxygen species (LOS) at high doses. Furthermore, the radical types arise independent from the irradiation wavelength, whereas the general amount of radical formation differs with the irradiation wavelength. Heat pre-stressed porcine skin already starts with higher LOS values. Thus, the radical type ratio might be an indicator of stress and the reversal of ROS/LOS constitutes the point where positive stress turns into negative stress.Compared to light skin types, darker types produce less radicals in the ultraviolet, similar amounts in the visible and higher ones in the infrared spectral region, rendering skin type-specific sun protection a necessity.

Relationship between salivary leukotriene B4 levels and salivary mucin or alveolar bone resorption, in subjects with periodontal health and disease.

OBJECTIVE: Here we determine the salivary levels of leukotriene B4 (LTB4 ) and its relation with salivary mucin and alveolar bone level. BACKGROUND: LTB4 is a membrane-derived lipid mediator formed from arachidonic acid. It is among the most potent stimulants of polymorphonuclear leukocytes providing the first host defense against infections. Leukotrienes also induce bone resorption. Because LTB4 is present in the oral cavity the aim of the present study was to explore the role of LTB4 in patients with periodontal disease. METHODS: Eighty-one subjects were clinically examined and distributed into four groups, namely, clinically healthy, mild, moderate and severe periodontitis, according to periodontal status, classified into values of clinical attachment level and probing pocket depth. Unstimulated saliva was collected for 5 min. Salivary LTB4 was determined by an immune assay method, mucin was determined by a colorimetric method and radiographic assessment used to determine alveolar bone level. RESULTS: Patients with mild periodontitis showed a decrease in salivary LTB4 levels while patients with severe periodontitis showed increased LTB4 levels. A significant positive correlation was observed between salivary LTB4 and clinical attachment level, salivary mucin concentration or alveolar bone level. CONCLUSION: The close relation between salivary LTB4 and mucin levels suggested that LTB4 might be involved in the defense mechanism of the oral cavity. The correlation of LTB4 with the alveolar bone level indicates that they are one of the mediators responsible for bone resorption.

Relationship between salivary mucin or amylase and the periodontal status.

OBJECTIVE: Here we determine the relationship between salivary levels of mucin and amylase and the clinical parameters of periodontal disease before and after periodontal treatment. SUBJECTS: Ninety two subjects were clinically examined and distributed into four groups namely clinically healthy, mild, moderate and severe periodontitis, according to the periodontal status, classified according the values of clinical attachment level (CAL) and probing pocket depth (PPD). Unstimulated saliva was collected for 5 min. Salivary proteins, amylase and mucin were determined by colorimetric methods. RESULTS: A significant positive correlation (P < 0.0001) was observed between salivary mucin, amylase or protein and PPD or CAL before periodontal treatment while flow rate showed a negative correlation. Mucin and amylase output also showed a positive correlation with PPD or CAL. After treatment, the improvement of clinical parameters was accompanied by a diminution of salivary mucin, amylase or protein concentration and output in moderate and severe group. CONCLUSIONS: The increment of mucin and amylase output in relation to periodontal status indicates that salivary glands respond to the disease by increasing the protective potential of saliva when necessary and return to the normal rate of secretion after the resolution of the inflammatory process.

Influence of the initial rupture size and tendon subregion on three-dimensional biomechanical properties of single-row and double-row rotator cuff reconstructions.

PURPOSE: Influence of the initial rotator cuff tear size and of different subregions of the SSP tendon on the cyclic loading behavior of a modified single-row reconstruction compared to a suture-bridging double-row repair. METHODS: Artificial tears (25 and 35 mm) were created in the rotator cuff of 24 human cadaver shoulders. The reconstructions were performed as a single-row repair (SR) using a modified suture configuration or a suture-bridge double-row repair (DR). Radiostereometric analysis was used under cyclic loading (50 cycles, 10­180 N, 10­250 N) to calculate cyclic displacement in three different planes (anteroposterior (x), craniocaudal (y) and mediolateral (z) level). Cyclic displacement was recorded, and differences in cyclic displacement of the anterior compared to the posterior subregions of the tendon were calculated. RESULTS: In small-to-medium tears (25 mm) and medium-to-large tears (35 mm), significant lower cyclic displacement was seen for the SR-reconstruction compared to the DR-repair at 180 N (p ≤ 0.0001; p = 0.001) and 250 N (p = 0.001; p = 0.007) in the x-level. These results were confirmed in the y-level at 180 N (p = 0.001; p = 0.0022) and 250 N (p = 0.005; p = 0.0018). Comparison of the initial tear sizes demonstrated significant differences in cyclic displacement for the DR technique in the x-level at 180 N (p = 0.002) and 250 N (p = 0.004). Comparison of the anterior versus the posterior subregion of the tendon revealed significant lower gap formation in the posterior compared to the anterior subregions in the x-level for both tested rotator cuff repairs (p ≤ 0.05). CONCLUSIONS: The tested single-row repair using a modified suture configuration achieved superior results in three-dimensional measurements of cyclic displacement compared to the tested double-row suture-bridge repair. The results were dependent on the initial rupture size of the rotator cuff tear. Furthermore, significant differences were found between tendon subregions of the rotator cuff with significantly higher gap formation for the anterior compared to the posterior subregions.

Values and public acceptability dimensions of sustainable egg production.

The attributes of egg production that elicit values-based responses include the price and availability of eggs, environmental impacts, food safety or health concerns, and animal welfare. Different social groups have distinct interests regarding the sustainability of egg production that reflect these diverse values. Current scientifically based knowledge about how values and attitudes in these groups can be characterized is uneven and must be derived from studies conducted at varying times and using incomplete study methods. In general, some producer and consumer interests are translated through markets and are mediated by market mechanisms, whereas others are poorly reflected by economic behavior. An array of survey and focus group research has been performed to elicit consumer and activist beliefs about performance goals they would expect from an egg production system. These studies provide evidence that consumers' market behavior may be at odds with their ethical and political beliefs about performance goals.

Determination of salivary levels of mucin and amylase in chronic periodontitis patients.

BACKGROUND AND OBJECTIVE: Patients with periodontal disease show differences in the profile of proteins in whole saliva. This profile reflects the nature and amplitude of the host response to a periodontal microbial challenge. Since periodontitis is a chronic inflammatory disease with different progression stages, the aim of the study was to evaluate the host response in these different clinical stages by assessing salivary flow rate, the concentrations of proteins and mucin and the amylase activity. MATERIAL AND METHODS: Sixty adult subjects were clinically examined and distributed into four groups (n = 15) according to the periodontal status, namely, healthy, mild, moderate and severe periodontitis. Whole saliva was collected for 5 min, followed by a second 5 min sampling period with stimulation by chewing a paraffin block, and flow rate was determined. Salivary proteins, amylase and mucin were determined by colorimetric methods. RESULTS: The concentrations of proteins, amylase and mucin increased in subjects with moderate and severe periodontal disease in unstimulated saliva, while flow rate decreased. A positive correlation was found between proteins and amylase or mucin concentrations among the different groups, indicating that the concentrations changed in the same way, being the response of salivary glands to the disease, possibly to enhance the protective potential of saliva. Mucin concentration was lower in the mild periodontitis group. Mechanical stimulation induced an increase in flow rate and output of proteins, amylase and mucin. CONCLUSION: Periodontitis induces an increase in the output of proteins, including mucin and amylase, thereby enhancing the protective potential of saliva, but this is accompanied by a decrease in flow rate.

Increase nitric oxide synthase activity in parotid glands from rats with experimental periodontitis.

OBJECTIVE: In this study we investigated the activity of the nitric oxide synthase (NOS) in parotid glands from rats with experimental periodontitis and controls. METHODS: Periodontitis was produced by a ligature placed around the cervix of the two lower first molar. Experiments were carried out 22 days after the ligature. RESULTS: Ligation caused an increase in parotid NOS activity. The selective blocker of the inducible isoform of the enzyme partially inhibited its activity in parotid glands from rat with ligature. In controls, the activity was partially inhibited by the antagonists of the selective neural and endothelial isoforms. NOS activity in rats with ligature was cyclic adenosine monophosphate (cAMP)-dependent while in controls it was calcium-dependent. Prostaglandin E2 concentration was increased in parotid gland from rats with ligature. The inhibitor of prostaglandin production, FR 122047, diminished both, prostaglandin production and NOS activity. In rats with ligature unstimulated amylase released is increased. Both, prostaglandin and NOS were involved in the increment of amylase release. CONCLUSION: It can be concluded that in parotid glands from ligated rats, prostaglandin E2 production is increased and, through cAMP accumulation, activates the inducible NOS isoform. The increment of nitric oxide production participates in the increase in basal amylase release.

Temperature elevation during simulated polymethylmethacrylate (PMMA) cranioplasty in a cadaver model.

The aims of this study were to: (i) obtain temperature measurements during in vitro polymerisation of polymethylmethacrylate (PMMA) disks of a range of thicknesses; and (ii) obtain tissue temperature measurements at various locations within a skull defect during a simulated PMMA cranioplasty procedure using a cadaver. In vitro, higher temperatures were recorded with increasing PMMA thickness. During the simulated cranioplasty, the maximum temperature was observed inside the PMMA sample, with nearby tissues being exposed to temperatures of greater than 50 degrees C over prolonged periods. There is conflicting information in the literature concerning the sensitivity of brain tissue and bone to elevated temperatures. Preoperatively fabricated PMMA cranioplasty prostheses are recommended.

A non-invasive device to objectively measure tibial rotation: verification of the device.

The purpose of this study was the correlation of the results of a new measurement device for tibial rotation (Rotameter) in comparison with the measurements of a knee navigation system as standard method. In a biomechanical laboratory study, all soft tissues were removed from 20 human cadaveric knees leaving only the intact capsule and the bone. Specific tracers were bicortically fixed in the bone in order to measure tibial rotation using a knee navigation system. The knees were fixed to a custom-made inside-boot to rule out undesirable rotation of the reconstruction inside the Rotameter measurement device. Internal and external rotation values were measured at an applied torque of 5, 10 and 15 Nm. The different methods to evaluate tibial rotation were compared using the Pearson correlation coefficient. The correlations were deemed to be reliable if a value of >or=0.80 was achieved. At 5 Nm of applied torque, high correlations for the internal rotation, external rotation and the entire rotational range were found in the Pearson correlation coefficient between the Rotameter testing device in comparison with the knee navigation system as invasive reference method. These results were also confirmed at an applied torque of 10 and 15 Nm. In conclusion, the Rotameter testing device showed high correlations compared with the knee navigation system as an invasive standard method. It might be used as a non-invasive and easy alternative to investigate tibial rotation.

Endogenous signalling system involved in parotid gland adenosine A(1) receptor-amylase release.

AIM: In this study, we have determined signalling pathways involved in adenosine A(1) receptor (A(1) receptor)-dependent stimulation of amylase release in rat parotid gland. METHODS: Amylase release, binding and cyclic adenosine monophosphate (cAMP) assays, inositol phosphates (IPs) production and nitric oxide synthase (NOS) activity in the presence of cyclopentyl-1,3-dipropylxanthine (CPA) alone or in the presence of different inhibitory drugs were performed. RESULTS: The binding parameters of specific A(1) antagonist [(3)H]-cyclopentyl 1,3-dipropilxanthine ([(3)H]-DPCPX) in parotid gland membranes show a population of high affinity sites with K(d) (nm) 0.53 +/- 0.06 and B(max) (fmol mg(-1) protein) 122.6 +/- 10.2. CPA stimulation of A(1) receptor exerts an increase in amylase release, IPs accumulation, cAMP production and NOS activity. All these A(1) agonist effects were blocked by the A(1) receptor antagonist DPCPX. Inhibitors of phospholipase C (PLC), calcium/calmodulin (CaM), protein kinase C (PKC), and adenylate cyclase, but not NOS, activities attenuated the CPA stimulatory effect on amylase release. The effect of CPA on amylase release significantly correlated with its action either on cAMP or on IPs accumulation. CONCLUSION: These results suggest that CPA activation of parotid gland A(1) receptor induces a stimulatory effect on amylase release associated with increased production of cAMP and IPs accumulation. The mechanism appears to occur secondarily to stimulation of phosphoinositide turnover via PLC activation. This, in turn, triggers cascade reactions involving CaM and PKC. The CPA stimulation of NOS does not appear to participate in amylase release.

CAD generated mold for preoperative implant fabrication in cranioplasty.

Intraoperative fabrication of acrylic cranial implants may be difficult and will increase operation time. In addition forming implants directly on the defect, intracranial tissues are exposed to heat of polymerization and residual monomer, that occurs, when autopolymerizing methyl methacrylate is used intraoperatively. Furthermore the cosmetical result may be unacceptable. Preoperatively formed acrylic implants may reduce these disadvantages compared to conventional techniques in cranioplasty. We will present methods for preoperative fabrication of cranial implants for a cadaver specimen. Implants were fabricated using a Rapid prototyping (RP) models of the skull built by Fused Deposition Modeling (FDM). In addition a mold of the defect was generated by CAD techniques, that can serve as a template for implant design.

The anterior glenohumeral joint capsule: macroscopic and MRI anatomy of the fasciculus obliquus or so-called ligamentum glenohumerale spirale.

The purpose of this study was to demonstrate the macroscopic and MRI anatomy of the fasciculus obliquus, otherwise known as the ligamentum glenohumerale spirale or spiral GHL of the anterior shoulder joint capsule. Conventional and MR arthrography (1.5-T device Somatom Symphony, Siemens with shoulder coil) images in standard planes were compared with gross anatomic dissection findings in six fresh shoulder specimens from three cadavers. The MR imaging protocol included T1, PD and DESS 3D WI sequences. The macroscopically recognisable band-the spiral GHL-was identified by anatomic dissection and MRI in all the specimens. It was best visualised by MR arthrography on axial and oblique sagittal planes (T1; PD WI) and appeared as a low signal intensity stripe within the superficial layer of the anterior joint capsule. The absence of the variable middle glenohumeral ligament did not influence the anatomic properties and the MR imaging of the spiral GHL. Diagnostic visualisation of the normal anatomic structures is a prerequisite to distinguish between normal and pathologic conditions. Anatomy of the spiral GHL can be used by radiologists for more detailed interpretation of the anterior shoulder joint capsule ligaments on MR images.

Medical biomodelling in surgical applications: results of a multicentric European validation of 466 cases.

The study started in September 1999 and ended in April 2002. It is based on a questionnaire [www.phidias.org] assessing case-related questions due to the application of stereolithographic models. Each questionnaire contains over 50 items. These variables take into account diagnosis, indications and benefits of stereolithographic models with view on different steps of the surgical procedures: preoperative planning, intraoperative application and overall outcome after surgical intervervention. These questionnaires were completed by the surgeons who performed operation. Over the time course of our multicentric study (30 months), we evaluated 466 cases. The study population consists of n=231 male and n= 235 female patients. 54 surgeons from 9 European countries were involved. There are main groups of diagnosis that related to the use of a model. Most models were used in maxillofacial surgery. The operative planning may help to determine the resection line of tumor and optimize reconstructive procedures. Correction of large calvarian defects can be simulated and implants can be produced preoperatively. Overall in 58 % of all cases a time- saving effect was reported. The study strongly suggests, that medical modeling has utility in surgical specialities, especially in the craniofacial and maxillofacial area, however increasingly in the orthopedic field. Due to our results, medical modeling optimizes the preoperative surgical planning. Surgeons are enabeled to perform realistic and interactive simulations. The fabrication of implants, its design and fit on the model, allow to reduce operation time and in consequence risk and cost of operation. In addition, the understanging of volumetric data is improved, especially if medical models are combined with standart imaging modalities. Finally, surgeons are able to improve communication between their patientents and colleagues.

Nitric oxide synthase/PGE(2) cross-talk in rat submandibular gland.

It is known that nitric oxide modulates the prostaglandin generation. However, little is known about the regulatory action of prostaglandin on nitric oxide production. There is a molecular cross-talk between nitric oxide and prostaglandin. Here, we examined biochemical signalling pathways coupled to the prostaglandin E(2) (PGE(2)) receptor related to nitric oxide synthase stimulation in rat submandibular gland. PGE(2) through the stimulation of its own receptor, triggered activation of phosphoinositide turnover (IPs), translocation of protein kinase C (PKC), stimulation of nitric oxide synthase activity (NOS) and increased production of cyclic GMP (cGMP). PGE(2) stimulation of NOS and cGMP production was blunted by agents interfering with calcium influx, calcium/calmodulin and phospholipase C (PLC) activities; while PKC inhibitor was able to stimulate PGE(2) effects. PGE(2) did not evoke amylase release, indicating that NOS/ cGMP pathway were not associated with this enzyme secretion. Our results suggest that this prostanoid could act as vasoactive chemical mediator through its ability to activate NOS-cGMP pathway via own gland membrane receptor.

Multiple carboxyl-terminal regions of the EBV oncoprotein, latent membrane protein 1, cooperatively regulate signaling to B lymphocytes via TNF receptor-associated factor (TRAF)-dependent and TRAF-independent mechanisms.

Latent membrane protein 1 (LMP1) is an EBV-encoded transforming protein that strongly mimics the B cell-activating properties of a normal cellular membrane protein, CD40. LMP1 and CD40 both associate with the cytoplasmic adapter proteins called TNFR-associated factors (TRAFs). TRAFs 1, 2, and 3 bind to a region of LMP1 that is essential for EBV to transform B lymphocytes, carboxyl-terminal activating region (CTAR) 1. However, studies of transiently overexpressed LMP1 molecules, primarily in epithelial cells, indicated that a second region, CTAR2, is largely responsible for LMP1-mediated activation of NF-kappaB and c-Jun N-terminal kinase. To better understand LMP1 signaling in B lymphocytes, we performed a structure-function analysis of the LMP1 C-terminal cytoplasmic domain stably expressed in B cell lines. Our results demonstrate that LMP1-stimulated Ig production, surface molecule up-regulation, and NF-kappaB and c-Jun N-terminal kinase activation require both CTAR1 and CTAR2, and that these two regions may interact to mediate LMP1 signaling. Furthermore, we find that the function of CTAR1, but not CTAR2, correlates with TRAF binding and present evidence that as yet unidentified cytoplasmic proteins may associate with LMP1 to mediate some of its signaling activities.

Anatomical accuracy in medical 3D modeling.

In complex surgery, medical modeling has become an accepted tool for diagnosis, simulation and the planning of surgical interventions [1]. However, the question concerning the accuracy of the model, i.e. the equivalence between the model itself on the one hand and the original anatomical situation on the other hand, remains unanswererd in the current literature.