Revisiting column selectivity choices in ultra-high performance liquid chromatography-Using multidimensional analytical Design Spaces to identify column equivalency

Current guides and column selection system (CSS) platforms can provide some helpful insights with regard to the selection of alternative phases. Their practical reliability however, can also turn out to be questionable, especially considering the lack of detailed specifics, such as a clear definition of points of equivalence-appropriate running conditions under which the given analytical mixture can be satisfactorily resolved on various stationary phases. In this context, the use of multivariate modeling tools can be highly beneficial. These tools, when applied systematically, are ideal for uniquely characterizing complex LC-separation systems, a fact supported by numerous peer-reviewed papers. Revisiting our earlier work [1] and the applied systematic workflow [2], we used a Design Space modeling software (DryLab), with the main focus on building and comparing 3-dimensional separation models of amlodipine and its related impurities to identify shared method conditions under which columns are conveniently interchangeable. Our study comprised 5, C18-modified ultra-high performance liquid chromatography (UHPLC) columns in total, in some cases with surprising results. We identified several equivalences between the Design Spaces (DSs) of markedly different columns. Conversely, there were cases where, despite the predicted similarities in column data, the modeled DSs demonstrated clear differences between the selected stationary phases.

The Semmelweis Study: a longitudinal occupational cohort study within the framework of the Semmelweis Caring University Model Program for supporting healthy aging

The Semmelweis Study is a prospective occupational cohort study that seeks to enroll all employees of Semmelweis University (Budapest, Hungary) aged 25 years and older, with a population of 8866 people, 70.5% of whom are women. The study builds on the successful experiences of the Whitehall II study and aims to investigate the complex relationships between lifestyle, environmental, and occupational risk factors, and the development and progression of chronic age-associated diseases. An important goal of the Semmelweis Study is to identify groups of people who are aging unsuccessfully and therefore have an increased risk of developing age-associated diseases. To achieve this, the study takes a multidisciplinary approach, collecting economic, social, psychological, cognitive, health, and biological data. The Semmelweis Study comprises a baseline data collection with open healthcare data linkage, followed by repeated data collection waves every 5 years. Data are collected through computer-assisted self-completed questionnaires, followed by a physical health examination, physiological measurements, and the assessment of biomarkers. This article provides a comprehensive overview of the Semmelweis Study, including its origin, context, objectives, design, relevance, and expected contributions.

Updating the European Pharmacopoeia impurity profiling method for cetirizine and suggesting alternative column, using design space comparison

The goal of the present study was to develop a generic workflow to evaluate the chromatographic resolution in a design space and find replacement column for the new method. To attain this objective, a limited number of initial experiments have been performed, and a modeling tool was employed to study and compare design spaces obtained with different columns. By overlaying the different individual resolution maps (design spaces), it is possible to quickly identify a robust zone where the different columns meet a given resolution criterion. This new feature of the modeling tool is very useful for finding alternative columns for a given separation, rather than the usual column tests. It was also demonstrated that two different columns can be used as equivalents (replacement columns), providing sufficient resolution at the same working point and with a high degree of robustness.

Challenges and opportunities for improvement in the management and financing system of Health Promotion Offices in Hungary

Background

One hundred ten Health Promotion Offices (HPOs) have started operating in Hungary in response to public health challenges. Many of them have been active for almost 10 years, yet their operational experience has not been evaluated. The specific objectives of our study were: (1) to describe the current operational and funding system of HPOs, (2) to identify challenges related to the current management and funding practices, and (3) to formulate recommendations for improvement based on gathered experience and international experience.

Design

In order to gain a deeper insight into the operational experience of HPOs, an online survey was conducted with the professional or economic managers of HPOs. A scoping review was carried out to gather international experiences about best practices to formulate recommendations for improvement in developing the operational and financing scheme for HPOs.

Results

We found that current HPO network in Hungary faces three main challenges: a deficient management system, inflexible financing scheme, and unequal ability to purchase or provide services for the population.

Conclusions

Based on the survey complemented by international experiences, we propose the overhaul of the professional management system and switching toa combination of fixed and performance-based financing scheme for the HPOs in Hungary.

International practices in health technology assessment and public financing of digital health technologies: recommendations for Hungary

Background

Evaluating and integrating digital health technologies is a critical component of a national healthcare ecosystem in the 2020s and is expected to even increase in significance.

Design

The paper gives an overview of international practices on public financing and health technology assessment of digital health technologies (DHTs) in five European Union (EU) countries and outlines recommendations for country-level action that relevant stakeholders can consider in order to support uptake of digital health solutions in Hungary. A scoping review was carried out to identify and gather country-specific classifications and international practices on the financing DHTs in five pioneering EU countries: Germany, France, Belgium, the United Kingdom and Finland.

Results

Several frameworks have been developed for DHTs, however there is no single, unified framework or method for classification, evaluation, and financing of digital health technologies in European context. European countries apply different taxonomy, use different assessment domains and regulations for the reimbursement of DHTs. The Working Group of the Hungarian Health Economic Society recommends eight specific points for stakeholders, importantly taking active role in shaping common clinical evidence standards and technical quality criteria across in order for common standards to be developed in the European Union single market.

Conclusion

Specificities of national healthcare contexts must be taken into account in decisions to allocate public funds to certain therapies rather than others.

The Effectiveness of Supplementation with Key Vitamins, Minerals, Antioxidants and Specific Nutritional Supplements in COPD-A Review

Currently, an increasing amount of evidence supports the notion that vitamins C, D and E, carotenoids, and omega-3 fatty acids may protect against the progression of chronic respiratory diseases. Although chronic obstructive pulmonary disease (COPD) primarily affects the lung, it is often accompanied by extrapulmonary manifestations such as weight loss and malnutrition, skeletal muscle dysfunction, and an excess of harmful oxidants, which can lead to a decline in quality of life and possible death. Recently, the role of various vitamins, minerals, and antioxidants in mitigating the effects of environmental pollution and smoking has received significant attention. Therefore, this review evaluates the most relevant and up-to-date evidence on this topic. We conducted a literature review between 15 May 2018 and 15 May 2023, using the electronic database PubMed. Our search keywords included COPD, chronic obstructive pulmonary disease, FEV₁, supplementation: vitamin A, vitamin D, vitamin E, vitamin C, vitamin B, omega-3, minerals, antioxidants, specific nutrient supplementations, clinical trials, and randomized controlled trials (RCTs). We focused on studies that measured the serum levels of vitamins, as these are a more objective measure than patient self-reports. Our findings suggest that the role of appropriate dietary supplements needs to be reconsidered for individuals who are predisposed to or at risk of these conditions.

Effect of time-invariant pressure gradients on peak formation and efficiency in ultrahigh-pressure liquid chromatography

In chromatography, pressure can affect the retention factors of compounds significantly. In liquid chromatography, this effect is primarily related to the change in the molecular volume of solute during adsorption that is remarkably high for large biomolecules such as peptides and proteins. As a result, the migration velocities of chromatographic bands vary spatially through the column affecting the degree of band broadening. In this work, based on theoretical considerations, chromatographic efficiencies are studied under pressure-induced gradient conditions. The retention factor and migration velocity of different components are examined, and it is shown that components with the same retention time can have different migration patterns. The width of the initial band after injection is affected by the pressure gradient, providing significantly thinner initial bands for compounds with higher pressure sensitivity. In addition to classical band broadening phenomena, the influence of pressure gradients on band broadening is remarkable. The positive velocity gradient leads to extra band broadening. Our results clearly demonstrate that the zones are significantly wider at the end of the column if the change of molar volume of solute during adsorption is large. If the pressure drop is increasing, this effect becomes more significant. In the same time, the high release velocity of the bands somewhat counteracts the extra band broadening effect, however, it can not offset it perfectly. As a result, the separation efficiency of large biomolecules is decreased significantly due to the chromatographic pressure gradient. Under UHPLC conditions, the extent of apparent efficiency loss can reach up to 50% compared to the intrinsic efficiency of the column.

Increase in the Length of Lung Cancer Patient Pathway Before First-Line Therapy: A 6-Year Nationwide Analysis From Hungary

Objective: This study aimed to examine the characteristics of the lung cancer (LC) patient pathway in Hungary during a 6-years period.

Methods: This nationwide, retrospective study included patients newly diagnosed with LC (ICD-10 C34) between January 1, 2011, and December 31, 2016, using data from the National Health Insurance Fund (NHIF) of Hungary. The following patient pathway intervals were examined: system, diagnostic and treatment interval by age, gender, tumor type, study year and first-line LC therapy.

Results: During the 6-years study period, 17,386 patients had at least one type of imaging (X-ray or CT/MRI) prior to diagnosis, and 12,063 had records of both X-ray and CT/MRI. The median system interval was 64.5 days, and it was 5 days longer among women, than in men (68.0 vs. 63.0 days). The median system interval was significantly longer in patients with adenocarcinoma compared to those with squamous cell carcinoma or small cell lung cancer (70.4 vs. 64.0 vs. 48.0 days, respectively). Patients who received surgery as first-line treatment had significantly longer median system intervals compared to those receiving chemotherapy (81.4 vs. 62.0 days). The median system interval significantly increased from 62.0 to 66.0 days during the 6-years study period.

Conclusion: The LC patient pathway significantly increased in Hungary over the 6-years study period. There were no significant differences in the length of the whole LC patient pathway according to age, however, female sex, surgery as first-line treatment, and adenocarcinoma were associated with longer system intervals.

Significant Regional Differences in Lung Cancer Incidence in Hungary: Epidemiological Study Between 2011 and 2016

Objective: Hungary has one of the highest incidences and mortality rates of lung cancer (LC), therefore the objective of this study was to analyse and compare LC incidence and mortality rates between the main Hungarian regions.

Methods: This nationwide, retrospective study used data from the National Health Insurance Fund and included patients aged ≥20 years who were diagnosed with lung cancer (ICD-10 C34) between Jan 1, 2011 and Dec 31, 2016. Age-standardized incidence and mortality rates were calculated and compared for the main regions.

Results: The highest incidence rate in males was recorded in Northern Hungary (146.8/100,000 person-years [PY]), while the lowest rate was found in Western Transdanubia (94.7/100,000 PY in 2011). All rates showed a declining trend between 2011 and 2016, with the largest decrease in the Northern Great Plain (−20.0%; p = 0.008). LC incidence and mortality rates in women both showed a rising tendency in all regions of Hungary, reaching the highest in Central Hungary (59.86/100,000 PY in 2016). Lung cancer incidence and mortality rates in males correlated with the level of education and smoking prevalence (p = 0.006 and p = 0.01, respectively) in the regions. A correlation with GDP per capita and Health Development Index (HDI) index could also be observed in the Hungarian regions, although these associations were not statistically significant. No correlations could be detected between these parameters among females.

Conclusion: This analysis revealed considerable differences in the epidemiology of LC between the 7 main Hungarian regions. LC incidence and mortality rates significantly correlated with smoking and certain socioeconomic factors in men, but not in women. Further research is needed to explain the regional differences.

Theoretical study of the efficiency of liquid chromatography columns with particle size gradient

Modern analytical applications of liquid chromatography require more and more efficient columns. In this work, the possibility of utilizing particle size gradient in the chromatographic column was studied by a theoretical approach. In the course of our work three different scenarios of particle size gradients were considered with different shapes (linear, convex and concave). The evolution of bandwidth inside the column was plotted for each scenario. As a reference point, the bandwidth of the uniform column was used, which had the same pressure drop as the non-uniform column. According to our calculations, in isocratic elution mode, the non-uniform column does not offer any advantage compared to the uniform column, regardless the type of the particle size gradient. In gradient elution mode, however, extra band compression occurs was found. For negative particle size gradients, the final physical bandwidth was found to be approximately 1-4 % smaller than for uniform columns. This slight gain in efficiency in terms of bandwidth compression can be expanded to 5-8 % by the optimization of the limiting particle sizes. These optimized results are obtained when the final particle size is approximately 40% of the initial particle diameter.

Development of a Fast and Robust UHPLC Method for Apixaban In-Process Control Analysis

In-process control (IPC) is an important task during chemical syntheses in pharmaceutical industry. Despite the fact that each chemical reaction is unique, the most common analytical technique used for IPC analysis is high performance liquid chromatography (HPLC). Today, the so-called “Quality by Design” (QbD) principle is often being applied rather than “Trial and Error” approach for HPLC method development. The QbD approach requires only for a very few experimental measurements to find the appropriate stationary phase and optimal chromatographic conditions such as the composition of mobile phase, gradient steepness or time (tG), temperature (T), and mobile phase pH. In this study, the applicability of a multifactorial liquid chromatographic optimization software was studied in an extended knowledge space. Using state-of-the-art ultra-high performance liquid chromatography (UHPLC), the analysis time can significantly be shortened. By using UHPLC, it is possible to analyse the composition of the reaction mixture within few minutes. In this work, a mixture of route of synthesis of apixaban was analysed on short narrow bore column (50 × 2.1 mm, packed with sub-2 µm particles) resulting in short analysis time. The aim of the study was to cover a relatively narrow range of method parameters (tG, T, pH) in order to find a robust working point (zone). The results of the virtual (modeled) robustness testing were systematically compared to experimental measurements and Design of Experiments (DoE) based predictions.

Age and Gender Specific Lung Cancer Incidence and Mortality in Hungary: Trends from 2011 Through 2016

Objective: No assessment was conducted describing the age and gender specific epidemiology of lung cancer (LC) prior to 2018 in Hungary, thus the objective of this study was to appraise the detailed epidemiology of lung cancer (ICD-10 C34) in Hungary based on a retrospective analysis of the National Health Insurance Fund database.

Methods: This longitudinal study included patients aged ≥20 years with LC diagnosis (ICD-10 C34) between January 1, 2011 and December 31, 2016. Patients with different cancer-related codes 6 months before or 12 months after LC diagnosis or having any cancer treatment other than lung cancer protocols were excluded.

Results: Lung cancer incidence and mortality increased with age, peaking in the 70–79 age group (375.0/100,000 person-years) among males, while at 60–69 age group for females (148.1/100,000 person-years). The male-to-female incidence rate ratio reached 2.46–3.01 (p < 0.0001) among the 70–79 age group. We found 2–11% decrease in male incidence rate at most age groups, while a significant 1–3% increase was observed in older females (>60) annually during the study period.

Conclusion: This nationwide epidemiology study demonstrated that LC incidence and mortality in Hungary decreased in younger male and female population, however we found significant increase of incidence in older female population, similar to international trends. Incidence rates peaked in younger age-groups compared to Western countries, most likely due to higher smoking prevalence in these cohorts, while lower age LC incidence could be attributed to higher competing cardiovascular risk resulting in earlier mortality in smoking population.

Improvement in Lung Cancer Survival: 6-Year Trends of Overall Survival at Hungarian Patients Diagnosed in 2011-2016

Objective: Lung cancer is one of the most common cancers worldwide and its survival is still poor. The objective of our study was to estimate long-term survival of Hungarian lung cancer patients at first time based on a nationwide review of the National Health Insurance Fund database.

Methods: Our retrospective, longitudinal study included patients aged ≥20 years who were diagnosed with lung cancer (ICD-10 C34) between January 1, 2011 and December 31, 2016. Survival rates were evaluated by year of diagnosis, patient gender and age, and morphology of lung cancer.

Results: 41,854 newly diagnosed lung cancer patients were recorded. Mean age at diagnosis varied between 64.7 and 65.9 years during study period. One- and 5-year overall survival rates for the total population were 42.2 and 17.9%, respectively. Survival was statistically associated with gender, age and type of lung cancer. Female patients (n = 16,362) had 23% better survival (HR: 0.77, 95% confidence interval (CI): 0.75–0.79; p < 0.001) than males (n = 25,492). The highest survival rates were found in the 20–49 age cohort (5Y = 31.3%) and if the cancer type was adenocarcinoma (5Y = 20.5%). We measured 5.3% improvement (9.2% adjusted) in lung cancer survival comparing the period 2015–2016 to 2011–2012 (HR: 0.95 95% CI: 0.92–0.97; p = 0.003), the highest at females <60 year (0.86 (adjusted HR was 0.79), interaction analysis was significant for age and histology types.

Conclusion: Our study provided long-term Lung cancer survival data in Hungary for the first time. We found a 5.3% improvement in 5-year survival in 4 years. Women and young patients had better survival. Survival rates were comparable to–and at the higher end of–rates registered in other East-Central European countries (7.7%–15.7%).

Impact of the column on effluent pH in cation exchange pH gradient chromatography, a practical study

In ionexchange chromatography, the pH gradient mode becomes more and more popular today for the analysis of therapeutic proteins as this mode can provide higher or alternative selectivity to the commonly used salt gradient mode. Ideally, a linear pH response is expected when performing linear gradients. However up to now, only a very few buffer systems have been developed and are commercially available which can perform nearly linear pH responses when flowing through a given column. It is also known that a selected buffer system (mobile phase) can work well on one column but can fail on other column. The goal of this study was to practically evaluate the effects that ionexchange columns (weak and strong exchangers) might have on effluent pH, when performing linear pH gradient separations of therapeutic monoclonal antibodies. To attain this objective, the pH was monitored on-line at the column outlet using a specific setup. To make comprehensive observations of the phenomenon, four different mobile phase conditions and five cation exchange columns (weak and strong exchangers) were employed. The obtained pH responses were systematically compared to responses measured in the absence of the columns. From this work, it has become clear that both the column and mobile phase can have significant effects on pH gradient chromatography and that their combination must be considered when developing a new method. Phase systems (column + mobile phase) providing linear pH responses are indeed the most suitable for separating mAbs with different isoelectric points and, with them, it is possible to elute mAbs across wide retention time ranges and with high selectivity.

EFFECT OF DIFFERENT ECOLOGICAL CONDITIONS ON CONTENT OF PHYTONUTRIENTS IN INDUSTRIAL TOMATOES

Tomatoes (Solanum lycopersicon L.) are one of the most important and most widely consumed vegetables in the world. The fruit contains considerable amount of different phytonutrients such as carotenoids, tocopherols, and vitamin C. In the present work, effects of some abiotic factors on the concentration of phytonutrients were investigated in tomato cultivated in two different types of soil. It was found that the type of soil had slight effect on the most important vital nutrients, while the ecological factors, particularly precipitation and average temperature 3 weeks before harvest, were of significant influence on such nutrients. It was found that low temperature and high precipitation before harvest caused the levels of carotenoids, tocopherol, and vitamin C to significantly increase by 65%, 46%, and 28%, respectively.

Revising Incidence and Mortality of Lung Cancer in Central Europe: An Epidemiology Review From Hungary

Objective: While Hungary is often reported to have the highest incidence and mortality rates of lung cancer, until 2018 no nationwide epidemiology study was conducted to confirm these trends. The objective of this study was to estimate the occurrence of lung cancer in Hungary based on a retrospective review of the National Health Insurance Fund (NHIF) database.

Methods: Our retrospective, longitudinal study included patients aged ≥20 years who were diagnosed with lung cancer (ICD-10 C34) between 1 Jan 2011 and 31 Dec 2016. Age-standardized incidence and mortality rates were calculated using both the 1976 and 2013 European Standard Populations (ESP).

Results: Between 2011 and 2016, 6,996 – 7,158 new lung cancer cases were recorded in the NHIF database annually, and 6,045 – 6,465 all-cause deaths occurred per year. Age-adjusted incidence rates were 115.7–101.6/100,000 person-years among men (ESP 1976: 84.7–72.6), showing a mean annual change of − 2.26% (p = 0.008). Incidence rates among women increased from 48.3 to 50.3/100,000 person-years (ESP 1976: 36.9–38.0), corresponding to a mean annual change of 1.23% (p = 0.028). Age-standardized mortality rates varied between 103.8 and 97.2/100,000 person-years (ESP 1976: 72.8–69.7) in men and between 38.3 and 42.7/100,000 person-years (ESP 1976: 27.8–29.3) in women.

Conclusion: Age-standardized incidence and mortality rates of lung cancer in Hungary were found to be high compared to Western-European countries, but lower than those reported by previous publications. The incidence of lung cancer decreased in men, while there was an increase in incidence and mortality among female lung cancer patients.

Analysis of Non-Ionic Surfactant Triton X-100 Using Hydrophilic Interaction Liquid Chromatography and Mass Spectrometry

It is well known that surfactants increase the solubility of hydrophobic organic compounds and cause adverse environmental effects. The removal of these compounds from the contaminated soil or ground-water is particularly difficult due to their water soluble feature. In this work, an ultra-high performance hydrophilic interaction liquid chromatographic method was developed for the separation of oligomers of Triton X-100 octylphenol-polyethoxylate non-ionic surfactant. Liquid chromatography-mass spectrometry (LC-MS) was used to identify the Triton X-100 compounds. There was a 44 mass unit difference between two adjacent peaks that is the molar mass of one ethylene oxide group (–CH2CH2O–). A quadratic retention model was applied for the estimation of retention of the examined non-ionic surfactant and the optimization of gradient elution conditions. The optimized method was suitable for the baseline separation of 28 Triton X-100 oligomers in five minutes.

Multilayer adsorption in liquid chromatography - The surface heterogeneity below an adsorbed multilayer

A numerical method was introduced for the estimation of the surface heterogeneity below an adsorbed multilayer of the analyte. The calculation procedure is based on the raw adsorption isotherm data points obtained by frontal analysis experiments. To permit the mapping of the nature of the analyte-surface interaction, a numerical procedure was used to pre-estimate the adsorbate-adsorbate interactions occurring during the adsorption process. The surface heterogeneity estimation was carried out using the affinity-energy distribution calculations with assuming local BET isotherm. In the local BET isotherm the pre-estimated adsorbate-adsorbate interaction constant was used, and the surface heterogeneity was described. After the test of the numerical method with benchmark isotherms, the algorithm was tested on several experimental isotherms. The isotherms were measured using phenol as test molecule on reversed phase adsorbents, with different surface coverage of the octadecyl ligands. The surface of the non-end-capped stationary phases showed detectable heterogeneity, while the surface end-capped phases were found to be homogeneous.

Influence of particle size and shell thickness of core-shell packing materials on optimum experimental conditions in preparative chromatography

The applicability of core-shell phases in preparative separations was studied by a modeling approach. The preparative separations were optimized for two compounds having bi-Langmuir isotherms. The differential mass balance equation of chromatography was solved by the Rouchon algorithm. The results show that as the size of the core increases, larger particles can be used in separations, resulting in higher applicable flow rates, shorter cycle times. Due to the decreasing volume of porous layer, the loadability of the column dropped significantly. As a result, the productivity and economy of the separation decreases. It is shown that if it is possible to optimize the size of stationary phase particles for the given separation task, the use of core-shell phases are not beneficial. The use of core-shell phases proved to be advantageous when the goal is to build preparative column for general purposes (e.g. for purification of different products) in small scale separations.

Solvent minimization in two-dimensional liquid chromatography

An algorithm was developed for the minimization of consumption of organic solvent in comprehensive two-dimensional liquid chromatography (2DLC). It was shown that one can reach higher peak capacities only by using more eluent. The equilibration volume of the second dimension, however, did not affect the solvent consumption significantly. Calculations confirmed that the same target peak capacity could be achieved by consuming significantly different volume of organic modifier depending on the number of fractions analyzed in the second dimension suggesting that 2D separations can be optimized for eluent consumption. It was shown that minimization of eluent usage requires the use of small and high efficient columns in the second dimension. A simple equation was derived for the calculation of the optimal number of collected fractions from the first dimension that allowed the minimization of eluent usage, cost and environmental impact of comprehensive 2DLC separations.

TiO₂-Mediated Photocatalytic Mineralization of a Non-Ionic Detergent: Comparison and Combination with Other Advanced Oxidation Procedures

Triton X-100 is one of the most widely-applied man-made non-ionic surfactants. This detergent can hardly be degraded by biological treatment. Hence, a more efficient degradation method is indispensable for the total mineralization of this pollutant. Application of heterogeneous photocatalysis based on a TiO₂ suspension is a possible solution. Its efficiency may be improved by the addition of various reagents. We have thoroughly examined the photocatalytic degradation of Triton X-100 under various circumstances. For comparison, the efficiencies of ozonation and treatment with peroxydisulfate were also determined under the same conditions. Besides, the combination of these advanced oxidation procedures (AOPs) were also studied. The mineralization of this surfactant was monitored by following the TOC and pH values, as well as the absorption and emission spectra of the reaction mixture. An ultra-high-performance liquid chromatography (UHPLC) method was developed and optimized for monitoring the degradation of Triton X-100. Intermediates were also detected by GC-MS analysis and followed during the photocatalysis, contributing to the elucidation of the degradation mechanism. This non-ionic surfactant could be efficiently degraded by TiO₂-mediated heterogeneous photocatalysis. However, surprisingly, its combination with the AOPs applied in this study did not enhance the rate of the mineralization. Moreover, the presence of persulfate hindered the photocatalytic degradation.

A three-year follow-up study of the development of joint contractures in 131 patients with systemic sclerosis

OBJECTIVES

To analyse the correlation between the number of joint-contractures and other major clinical findings in a follow-up study of 131 patients with systemic sclerosis (SSc).

METHODS

The range of motion of joints (ROM), HAQ-DI, and the major clinical characteristics were assessed.

RESULTS

A high frequency of contractures (ROM<75% of the normal) were present at baseline in small joints of the hand (82%), wrists (75%), and shoulders (50%). ROM of the dominant side hand was significantly more decreased compared to the non-dominant side. The number of the upper extremity contractures correlated positively with ESR (p<0.01), CRP (p<0.01), HAQ-DI (p<0.01), and negatively with forced vital capacity (FVC) (p<0.05). The number of contractures was not significantly different in cases with early (≤ 4 years) and late disease duration in both the limited and diffuse subgroups. During the three-year follow-up period, an increase in the number of joint contractures (ROM<75%) was associated with an increase of ESR, modified Rodnan's skin score, and the European Scleroderma Study Group Activity Index by multiple linear regression analysis. Univariate analysis over a six-year period demonstrated poor outcome in patients with more than ten contractures, or more than four contractures of unilateral hand-joints.

CONCLUSIONS

Contractures predominantly develop during the early years following disease onset in both SSc subgroups. Inflammation and skin-involvement are significant contributing factors for the development of contractures. The dominant hand may be more pronouncedly impaired compared to the non-dominant side. A high number of joint-contractures might be an unfavourable prognostic factor in SSc.

The role of MRI in the assessment of the local status of anal carcinomas and in their management

This study aims to define the role of Magnetic Resonance (MR) examinations in the assessment and therapy of anal cancer (AC), and to present the main features of the MR examinations and the typical tumor spread pattern. The MR examinations of 67 anal cancer patients with histologically confirmed planocellular cancer were analyzed retrospectively. The tumor size and the signal intensity, the nodal status were examined before and after the treatment, and in recidive tumors (N = 13). At the time of the diagnosis the primary tumor was in early stage (Tis, T1, T2) in 71.5 % of the cases, and it was localized in 97 %. In 97.4 % of the cases the tumor had relatively increased signal intensities compared to the adjacent muscles. Patients received chemo-radiotherapy (CRT). After CRT in 26 out of 39 patients (66.7 %) the size of the tumor decreased (in 75 %), and the signal intensity decreased on the T2 weighted (T2w) images. In the residual tumor cases (19/39) verified 6 patients out of 19 had further decrease in size, and signal intensity a year after the end of the therapy. The MR examination plays a key role in the therapy of AC, by assessing the precise local status, the possible recidive tumors, and monitoring the therapy.

Degradation of industrial surfactants by photocatalysis combined with ozonation

The efficiency of titanium dioxide-mediated photocatalytic degradation of pollutants can be enhanced by combination with another advanced oxidation procedure such as ozonation. Mineralization of hydroxy- and dihydroxybenzenesulfonate based on these methods, both individually and combined, was investigated by monitoring the total organic carbon content, sulfate concentration, pH, high-performance liquid chromatography as well as the absorption spectral changes. The mineralization efficiency of the combined procedure significantly exceeded the sum of those of the individual techniques. The comparison of the disappearance of the starting material and the formation of the sulfate ions indicates that desulfonation is not the primary step of the degradation. Moreover, in the case of the combined method, ring cleavage, and thus, partial mineralization can occur without desulfonation. Efficient degradation of other, widely used industrial surfactants, such as alkylbenzene sulfonates and alkyl ether sulfates, was also achieved by heterogeneous photocatalysis combined with ozonation, offering an applicable method for the removal of these pollutants.

Influence of pressure and temperature on molar volume and retention properties of peptides in ultra-high pressure liquid chromatography

In this study, pressure induced changes in retention were measured for model peptides possessing molecular weights between ∼1 and ∼4kDa. The goal of the present work was to evaluate if such changes were only attributed to the variation of molar volume and if they could be estimated prior to the experiments, using theoretical models. Restrictor tubing was employed to generate pressures up to 1000bar and experiments were conducted for mobile phase temperatures comprised between 30 and 80°C. As expected, the retention increases significantly with pressure, up to 200% for glucagon at around 1000bar compared to ∼100bar. The obtained data were fitted with a theoretical model and the determination coefficients were excellent (r(2)>0.9992) for the peptides at various temperatures. On the other hand, the pressure induced change in retention was found to be temperature dependent and was more pronounced at 30°C vs. 60 or 80°C. Finally, using the proposed model, it was possible to easily estimate the pressure induced increase in retention for any peptide and mobile phase temperature. This allows to easily estimating the expected change in retention, when increasing the column length under UHPLC conditions.

Clinical, radiological and genetic aspects of leukodystrophies

The authors summarize the pathomechanism of the myelination process, the clinical, radiological and the genetical aspects of the leukodystrophies, as in 18q deletion syndrome, adrenoleukodysrtophy, metachromatic leukodystrophy, Pelizaeus-Merzbacher leukodystrophy, Alexander disease and olivo-ponto-cerebellar atrophy (OPCA).

Plasma carnitine ester profiles in Crohn's disease and ulcerative colitis patients with different IGR2230a_1 genotypes

An association has been repeatedly demonstrated between inflammatory bowel disease (IBD) and the IBD5 locus in the 5q31 chromosomal region. The aim of the present study was to examine the prevalence of the IGR2230a_1 intronic nucleotide polymorphism of the slc22a5 gene (coding for the OCTN2 carnitine transporter protein) lying within this region, and its possible relationship with the carnitine metabolism in Hungarian IBD patients and controls. We genotyped by restriction fragment length polymorphism 200 Crohn's disease (CD) and 246 ulcerative colitis (UC) patients, as well as 187 healthy controls. From plasma samples we determined detailed carnitine ester profiles of 76 CD, 43 UC patients and 45 control persons using electrospray ionization triple quadruple tandem mass spectrometry. The distribution of the genotypes was not significantly different in the CD or the UC group compared with the controls. We found no significant alterations of the carnitine profile in the carrier/non-carrier or the homozygote/non-homozygote comparisons in both the CD and the UC groups, stratified by IGR2230a_1 genotype. Our data suggest that this polymorphism alone is not associated with CD and UC in the Hungarian population, and has no effect on the carnitine metabolism.

Optimization strategies for off-line two-dimensional liquid chromatography

A step by step strategy of optimization of comprehensive off-line two-dimensional liquid chromatography (2D-LC) separations is proposed. The goal of an optimization process in the separation sciences is either to achieve a given resolution (a target peak capacity in 2D-LC) within as short a time as possible or to reach the highest possible resolution in a given analysis time. The proposed method takes into account the characteristics of the columns used in the first and the second dimension and the number of fractions of the first dimension eluent that should be collected. The effect of the time spent during the analysis on the second dimension column to carry out necessary tasks that are not the separation itself (called the additional time) on the maximum peak capacity that is achievable was carefully investigated. It was shown that (1) an increase in the peak capacity of the first dimension column combined with the collection of larger volume fractions permits a significant reduction of the time needed to achieve the desired peak capacity; and (2) there is an optimum fraction collection ratio (or number of collected fractions per peak) which yields the target peak capacity in the minimum time. The proposed strategy was used for the optimization of the separation of samples of BSA tryptic digest by an off-line 2D-LC using an SCXmultiply sign in circleRP-HPLC method. As a result of this optimization, a peak capacity of 4000 could be achieved in about 5h with the two columns available. The time needed for the optimized analysis was less than two thirds of the analysis time that would have been needed had the conventional rule of thumb of sample collection in comprehensive on-line 2D-LC (4 samples/peak) been followed.

Approaches to comprehensive multidimensional liquid chromatography systems

This work compares the performance of the three different schemes implementing two-dimensional liquid chromatography (2D-LC) in terms of the peak capacity that they can generate and of the time that they need to complete a two-dimensional analysis. We discuss in detail how time is spent in these two-dimensional liquid chromatography x liquid chromatography (LC x LC) schemes and how to compare them. Keeping constant the characteristics of the first-dimension separation, we systematically varied those of the second-dimension separation and of its coupling to the first-dimension. In the process, five systems were created, based on the principles of the three known implementations of comprehensive 2D-LC. This work demonstrates an original method for the selection of the best comprehensive 2D-LC approach, depending on the desired peak capacity and on time constraints. The decision to use a 2D-LC method arises from the need to achieve a given resolution (i.e., a target peak capacity) within as short a time as possible or to reach the highest possible resolution in a given analysis time. Using the most appropriate schemes, we suggest how it is realistically possible to generate peak capacities ranging from 266 in just over 20 min or about 2800 in 2.3 h. When the time available for a two-dimensional separation is very short and the desired peak capacity cannot be achieved in 1D-LC, an on-line 2D-LC approach is unquestionably best. However, if a longer analysis time is acceptable, a 10-fold increase in the peak capacity can be obtained at the cost of a mere 7-fold increase in total analysis time.

Retention controlling and peak shape simulation in anion chromatography using multiple equilibrium model and stochastic theory

The stochastic theory of chromatography and an equilibrium based approach were used for the prediction of peak shape and retention data of anions. This attempt incorporating the potential advantages of two different chromatographic phenomena for analytical purposes. It is an integrated method to estimate kinetic and thermodynamic properties for the same chromatographic run of ions. The stochastic parameters of eluted anions, such as the residence time of the molecule on the surface of the stationary phase, and the average number of adsorption steps were determined on the basis of a retention database of organic and inorganic anions (formate, chloride, bromide, nitrate, sulphate, oxalate, phosphate) obtained by using carbonate/bicarbonate eluent system at different pHs (9-11) and concentrations (7-13 mM). In the investigated IC system the residence times are much higher and the average number of sorption steps is somewhat smaller than in RP-HPLC. The simultaneous application of the stochastic and the multispecies eluent/analyte model was utilized to peak shape simulation and the retention controlling of various anions under elution conditions of practical importance. The similarities between the measured and the calculated chromatograms indicates the predictive and simulation power of the combined application of the stochastic theory and the multiple species eluent/analyte retention model.