Urban heat load assessment in Zagreb, Croatia: a multi-scale analysis using mobile measurement and satellite imagery.

A limited number of meteorological stations and sparse data challenge microclimate assessment in urban areas. Therefore, it is necessary to complement these data with additional measurements to achieve a denser spatial coverage, enabling a detailed representation of the city's microclimatic features. In this study, conducted in Zagreb, Croatia, mobile air temperature measurements were utilized and compared with satellite-derived land surface temperature (LST). Here, air temperature measurements were carried out using bicycles and an instrument with a GPS receiver and temperature probe during a heat wave in June 2021, capturing the spatial pattern of air temperature to highlight the city's microclimate characteristics (i.e. urban heat load; UHL) in extremely hot weather conditions. Simultaneously, remotely sensed LST was retrieved from the Landsat-8 satellite. Air temperature measurements were compared to city-specific street type classification, while neighbourhood heat load characteristics were analysed based on local climate zones (LCZ) and LST. Results indicated significant thermal differences between surface types and urban forms and between street types and LCZs. Air temperatures reached up to 35 °C, while LST exceeded 40 °C. City parks, tree-lined streets and areas near blue infrastructure were 1.5-3 °C cooler than densely built areas. Temperature contrasts between LCZs in terms of median LST were more emphasised and reached 9 °C between some classes. These findings highlight the importance of preserving green areas to reduce UHL and enhance urban resilience. Here, exemplified by the city of Zagreb, it has been demonstrated that the use of multiple datasets allows a comprehensive understanding of temperature patterns and their implications for urban climate research.

Letter to the Editor: Comparing the Novel Parameter 'Slope of the Steepest Part of Hemolysis Curve' to Standard Median Corpuscular Fragility for Evaluating Erythrocyte Stability during Prolonged Storage.

OBJECTIVE: Several ways for presenting the results of osmotic fragility test have been described in the literature. Our aim was to compare the utility of a novel parameter for assessment of erythrocyte osmotic properties, i.e., 'Slope of the steepest part of hemolysis curve' with the most frequently used parameter 'Median corpuscular fragility' in order to assess the stability of erythrocytes in a blood sample during prolonged storage. METHODS: Ten whole blood samples were obtained from healthy donors. The osmotic fragility test was initially conducted on the day of venipuncture, and subsequent analyses were carried out on days 1, 2, 4, 7, 9, 11, and 14 after the venipuncture. Mean hemolysis percentage values were used to construct hemolysis curves. The steepest parts of hemolysis curves were estimated to be linear, and lines that overlapped those parts of the curves were created. The slope of these lines was calculated, and the resulting mean values are presented. RESULTS: A significant increase in Median corpuscular fragility values was observed, starting from day of venipuncture. We compared the average values for each day of analysis. The first significant difference in Median corpuscular fragility values was observed on day 4 compared to the day of venipuncture (p=0.006), with values 0.53±0.030 % and 0.41±0.014% respectively. Meanwhile, differences in the values of the slopes of the steepest parts of hemolysis curves were observed as early as day 2 when compared to the day of venipuncture (p=0.046), with values of -966.23±233.07 and -588.01±222.85, respectively. CONCLUSION: Prolonged storage of whole blood samples leads to an increase in osmotic fragility and alters the shape of the hemolysis curve. These changes suggest that postponing the osmotic fragility test could lead to diagnostic inaccuracies. These findings suggest that slope value is a more accurate parameter for evaluating erythrocyte stability during storage, compared to commonly used Median corpuscular fragility value. Hence, it has potential importance and can be complementary to the laboratory result of the OFT. Therefore, it can be useful to provide these results jointly with the results of the OFT test.

A relation of serum homocysteine and uric acid in Bosnian diabetic patients with acute myocardial infarction.

Background: Coronary artery disease as a consequence of atherosclerosis is the most common cause of morbidity and mortality in type 2 Diabetes Mellitus (DM) patients. Homocysteine (HCY), as one of the risk factors, and uric acid (UA) as the most common antioxidant in serum have their roles in the processes of inflammation and atherogenesis, which underlie the pathogenesis of acute myocardial infarction (AMI). The effect of HCY in cardiovascular disease is thought to be manifested primarily through oxidative damage, implying a potential correlation between the HCY level and antioxidant status. Since the data related to the diagnostic significance of both HCY and UA in diabetic patients with AMI are conflicting, and so far not reported in Bosnian patients, this research aimed to examine the association of HCY and UA levels with glomerular filtration rate (eGFR) and explore the pathophysiological significance of these data in Bosnian diabetic patients with AMI. Methods: This prospective research included 52 DM type 2 patients diagnosed with AMI. Blood samples were taken on admission and used for biochemical analysis. Results of the biochemical analyses were statistically analysed. Results: Elevated HCY and UA levels were observed in diabetic patients. Females have higher HCY compared to males. A positive correlation was revealed between HCY and UA and was confirmed with different HCY levels in subgroups with different UA level. A negative correlation was observed between UA and HbA1c, as well as between both HCY and UA with eGFR. Conclusions: These results contribute to the clarification of the biochemical mechanisms characteristic in AMI patients with DM. According to these results, we believe that joint measurement of HCY and UA could enable a better assessment of the prognosis for this group of patients. This kind of assessment, as well as regression analysis, can identify high-risk patients at an earlier stage when appropriate interventions can influence a better outcome in such patients.

A relation of serum homocysteine, uric acid and C-reactive protein level in patients with acute myocardial infarction.

Aim To determine the relationship of homocysteine (HCY), uric acid (UA) and C-reactive protein (CRP) in serum of patients with acute myocardial infarction (AMI) prior to application of percutaneous coronary intervention (PCI) and their level of correlation in serum of patients with normal and elevated CRP (predictor of worse cardiovascular outcomes). Methods The study involved 85 patients with diagnosed AMI. Before the PCI, venous blood samples were taken into the vacuum test tubes. The analysis of HCY, UA, inflammatory markers CRP and neutrophil to lymphocyte ratio (NLR) as well as lipoprotein status were performed on a different type of analysers and according to accepted protocols of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). Results Elevated level of both HCY and UA in AMI patients as well as a positive correlation between HCY and UA level was observed. Classification of patients on the basis of mean UA concentration showed significant difference at the level of HCY concentration (p=0.022). Conclusion Since HCY and UA participate in the atherosclerotic process and their metabolism, as well as the effects on the cardiovascular system show significant overlaps, their serum level should be analysed synchronously with the level of CRP and NLR (indicators of significant inflammatory process in vessels). Considering a potential link between all parameters observed, further research involving a greater number of patients and including the post treatment effects should be conducted.

Kappa Free Light Chains in Cerebrospinal Fluid of Patients with Identified Oligoclonal Immunoglobulin G.

BACKGROUND: Production of kappa free light chains (KFLC) represents a part of humoral immune response, along with the synthesis of intrathecal immunoglobulins. Increased concentrations of immunoglobulin G light chains, kappa and lambda chains, were identified through research of numerous diseases of central nervous system. The qualitative method of isoelectric focusing (IEF) followed by immunofixation currently represents the accepted standard in identifying oligoclonal bands (OCB), but establishing a sensitive immunonephelometric method for quantification of kappa free light chains (KFLC) in cerebrospinal fluid (CSF) has paved a way for new diagnostic possibilities. Andersson classified the pattern types of OCB, ranging from type 1 to type 5, wherein types 2 and 3 indicate intrathecal synthesis. Our aim was to determine KFLC in CSF of patients with clinically isolated syndrome (CIS) who had presented with type 2 and type 3 OCB, to determine if there is a difference in concentrations between those two groups and to establish a borderline value of KFLC which would enable differential diagnostics. SUBJECTS AND METHODS: 70 patients, who underwent lumbar punction for CSF analysis and had their blood sampled through the cubital vein, participated in the study. Patients were classified according to Andersson as type 2 or type 3, which besides adulthood, represented the inclusion criteria. The average age of patients classified as type 2 was 36 years, and those classified as type 3 was 39 years, where it is evident that there was not a statistically significant difference (p=0.0685). We used a qualitative electrophoretic technique of IEF with agarose gel followed by immunofixation, and a quantitative immunonephelometric method. All results were interpreted on a level of statistic significance of p<0.05. RESULTS: CSF KFLC concentrations in type 3 were statistically and significantly elevated with regard to type 2 (Mann-Whitney test, p=0.0430). The median for KFLC in type 2 was 0.9 mg/L, while the median for KFLC in type 3 was 2.71 mg/L, and the detection limit for both types was 0.18 mg/L. We used a statistical ROC curve to determine that KFLC concentration can be used for differential diagnostics, meaning it can discriminate type 2 from type 3 with clinical sensitivity of 61% and clinical specificity of 71% (AUC=0.641) (p=0.037). CONCLUSION: Despite the obtained statistically significant differences in concentrations of KFLC between types of OCBs and ROC analysis results, determination of KFLC by a nephelometric method, insufficiently strong clinical sensitivity and specificity does not justify abandonment of IEF method followed by immunofixation.