Comparison of Zn Content in Rapid-acting Insulin and Biphasic Suspension by FAAS

Various insulin analogs (rapid-acting and intermediate-acting insulin) have been investigated for the determination of zinc content by flame atomic absorption spectrometry. This paper presents the validation of a method and comparison of zinc content in the insulin samples studied. The method was linear (r)(^2) = 0.9997), the limit of detection was 0.0098 mg L(^{–1}) and the limit of quantification was 0.0296 mg L(^{–1}), the precision (as relative standard deviation) was up to 7.4 %, and the accuracy was within a range of 95.6 % to 100.1 % for the recovery of fortified insulin samples. The zinc content in the insulin samples ranged from 14.9 mg L(^{–1}) to 16.3 mg L(^{–1}) for rapid-acting insulin and 18.7 mg L(^{–1}) to 19.9 mg L(^{–1}) for intermediate-acting insulin. A higher zinc content was found in the intermediate-acting insulins than in the rapid-acting insulin analogs ((p) < 0.05). The obtained results should be considered in the establishment of new or improvement of currently available procedures used to assure the quality, safety and efficacy of insulin products. This work is licensed under a Creative Commons Attribution 4.0 International License

N-glycosylation of immunoglobulin A in type 1 diabetes mellitus

Šećerna bolest tipa 1 (T1DM) multifaktorska je, kronična i autoimuna bolest koja nastaje kao posljedica nedostatka endogenog lučenja inzulina iz β-stanica gušterače. Trenutno su dostupna dva biomarkera koji ukazuju na dugoročnu kontrolu dijabetesa – HbA1c i fruktozamin, ali oba imaju svoja ograničenja. Stoga, postoji velika potreba za markerom koji bi na precizniji način omogućio longitudinalno praćenje T1DM. Promjene u profilu N-glikozilacije ukupnih proteina plazme i imunoglobulina G u mnogim su se studijama pokazale kao potencijalni prognostički, dijagnostički i terapijski markeri raznih bolesti, posebice onih upalne prirode kao što je T1DM. Glikozilacija imunoglobulina A u različitim bolestima općenito je manje proučavana, a tek prije nekoliko godina započela su intenzivna istraživanja uloge njegove glikozilacije u T1DM. Cilj ovog istraživanja je identificirati promjene u IgA N-glikozilaciji u populaciji odraslih bolesnika s T1DM te ih usporediti sa zdravim osobama. Analiza glikana učinjena je HILIC-UPLC metodom. U ovom diplomskom radu je otkriveno da kod odraslih ispitanika s dijagnosticiranim T1DM postoji statistički značajna promjena udjela glikanskih struktura GP2, GP4, GP5, GP7, GP13, GP14, GP17, GP19, GP21, GP24, GP25, GP27 i GP29. Detaljnije proučavanje deriviranih svojstava pokazalo je smanjenje udjela nisko razgranatih glikana, a povećanje visoko razgranatih glikana. Nadalje, smanjenje udjela digalaktoziliranih glikana i povećanje udjela trigalaktoziliranih i trisijaliniziranih glikana pronađeno je u bolesnika s T1DM. Udio glikana sa sržnom fukozom značajno je smanjen u bolesnika s T1DM, dok je udio oligomanoznih glikana značajno povećan. Ove promjene u glikozilaciji IgA upućuju na njegovu moguću ulogu u progresiji bolesti te na potrebu daljnjeg ispitivanja njegove prognostičke vrijednosti.Type 1 diabetes mellitus (T1DM) is a multifactorial, chronic, and autoimmune disease that results from a lack of endogenous insulin secretion from pancreatic β-cells. There are two markers currently available that indicate long-term diabetes control – HbA1c and fructosamine, but both have their limitations. Therefore, there is a great need for a marker that would show the longitudinal progression of T1DM in a more precise way. Changes in the N-glycosylation profile of total plasma proteins and immunoglobulin G in many studies have proven to be a potential prognostic, diagnostic and therapeutic marker of various diseases, especially those of an inflammatory nature, such as T1DM. Glycosylation of immunoglobulin A in various diseases has generally been less studied, and only a few years ago, intensive research into the role of its glycosylation in T1DM began. The aim of this study is to identify changes in IgA N-glycosylation in the population of adult patients with T1DM and compare them with healthy individuals. Glycan analysis was done by ultra performance liquid chromatography based on hydrophilic interactions. In this thesis, it was discovered that in adult subjects diagnosed with T1DM there is a statistically significant change in the proportion of glycan structures GP2, GP4, GP5, GP7, GP13, GP14, GP17, GP19, GP21, GP24, GP25, GP27 and GP29. A more detailed study of the derived traits showed a decrease in the proportion of low-branched glycans, and an increase in highly branched glycans. Furthermore, a reduction in the proportion of digalactosylated glycans and an increase in the proportion of trigalactosylated and trisialinised glycans is found in T1DM patients. The proportion of glycans with core fucose was significantly reduced in T1DM patients, while the proportion of high mannose glycans was significantly increased. These changes in IgA glycosylation indicate that it has a possible role in the disease progression and the need for further examination of its prognostic value

N-glycosylation of immunoglobulin A in type 1 diabetes mellitus

Šećerna bolest tipa 1 (T1DM) multifaktorska je, kronična i autoimuna bolest koja nastaje kao posljedica nedostatka endogenog lučenja inzulina iz β-stanica gušterače. Trenutno su dostupna dva biomarkera koji ukazuju na dugoročnu kontrolu dijabetesa – HbA1c i fruktozamin, ali oba imaju svoja ograničenja. Stoga, postoji velika potreba za markerom koji bi na precizniji način omogućio longitudinalno praćenje T1DM. Promjene u profilu N-glikozilacije ukupnih proteina plazme i imunoglobulina G u mnogim su se studijama pokazale kao potencijalni prognostički, dijagnostički i terapijski markeri raznih bolesti, posebice onih upalne prirode kao što je T1DM. Glikozilacija imunoglobulina A u različitim bolestima općenito je manje proučavana, a tek prije nekoliko godina započela su intenzivna istraživanja uloge njegove glikozilacije u T1DM. Cilj ovog istraživanja je identificirati promjene u IgA N-glikozilaciji u populaciji odraslih bolesnika s T1DM te ih usporediti sa zdravim osobama. Analiza glikana učinjena je HILIC-UPLC metodom. U ovom diplomskom radu je otkriveno da kod odraslih ispitanika s dijagnosticiranim T1DM postoji statistički značajna promjena udjela glikanskih struktura GP2, GP4, GP5, GP7, GP13, GP14, GP17, GP19, GP21, GP24, GP25, GP27 i GP29. Detaljnije proučavanje deriviranih svojstava pokazalo je smanjenje udjela nisko razgranatih glikana, a povećanje visoko razgranatih glikana. Nadalje, smanjenje udjela digalaktoziliranih glikana i povećanje udjela trigalaktoziliranih i trisijaliniziranih glikana pronađeno je u bolesnika s T1DM. Udio glikana sa sržnom fukozom značajno je smanjen u bolesnika s T1DM, dok je udio oligomanoznih glikana značajno povećan. Ove promjene u glikozilaciji IgA upućuju na njegovu moguću ulogu u progresiji bolesti te na potrebu daljnjeg ispitivanja njegove prognostičke vrijednosti.Type 1 diabetes mellitus (T1DM) is a multifactorial, chronic, and autoimmune disease that results from a lack of endogenous insulin secretion from pancreatic β-cells. There are two markers currently available that indicate long-term diabetes control – HbA1c and fructosamine, but both have their limitations. Therefore, there is a great need for a marker that would show the longitudinal progression of T1DM in a more precise way. Changes in the N-glycosylation profile of total plasma proteins and immunoglobulin G in many studies have proven to be a potential prognostic, diagnostic and therapeutic marker of various diseases, especially those of an inflammatory nature, such as T1DM. Glycosylation of immunoglobulin A in various diseases has generally been less studied, and only a few years ago, intensive research into the role of its glycosylation in T1DM began. The aim of this study is to identify changes in IgA N-glycosylation in the population of adult patients with T1DM and compare them with healthy individuals. Glycan analysis was done by ultra performance liquid chromatography based on hydrophilic interactions. In this thesis, it was discovered that in adult subjects diagnosed with T1DM there is a statistically significant change in the proportion of glycan structures GP2, GP4, GP5, GP7, GP13, GP14, GP17, GP19, GP21, GP24, GP25, GP27 and GP29. A more detailed study of the derived traits showed a decrease in the proportion of low-branched glycans, and an increase in highly branched glycans. Furthermore, a reduction in the proportion of digalactosylated glycans and an increase in the proportion of trigalactosylated and trisialinised glycans is found in T1DM patients. The proportion of glycans with core fucose was significantly reduced in T1DM patients, while the proportion of high mannose glycans was significantly increased. These changes in IgA glycosylation indicate that it has a possible role in the disease progression and the need for further examination of its prognostic value

N-glycosylation of immunoglobulin A in type 1 diabetes mellitus

Šećerna bolest tipa 1 (T1DM) multifaktorska je, kronična i autoimuna bolest koja nastaje kao posljedica nedostatka endogenog lučenja inzulina iz β-stanica gušterače. Trenutno su dostupna dva biomarkera koji ukazuju na dugoročnu kontrolu dijabetesa – HbA1c i fruktozamin, ali oba imaju svoja ograničenja. Stoga, postoji velika potreba za markerom koji bi na precizniji način omogućio longitudinalno praćenje T1DM. Promjene u profilu N-glikozilacije ukupnih proteina plazme i imunoglobulina G u mnogim su se studijama pokazale kao potencijalni prognostički, dijagnostički i terapijski markeri raznih bolesti, posebice onih upalne prirode kao što je T1DM. Glikozilacija imunoglobulina A u različitim bolestima općenito je manje proučavana, a tek prije nekoliko godina započela su intenzivna istraživanja uloge njegove glikozilacije u T1DM. Cilj ovog istraživanja je identificirati promjene u IgA N-glikozilaciji u populaciji odraslih bolesnika s T1DM te ih usporediti sa zdravim osobama. Analiza glikana učinjena je HILIC-UPLC metodom. U ovom diplomskom radu je otkriveno da kod odraslih ispitanika s dijagnosticiranim T1DM postoji statistički značajna promjena udjela glikanskih struktura GP2, GP4, GP5, GP7, GP13, GP14, GP17, GP19, GP21, GP24, GP25, GP27 i GP29. Detaljnije proučavanje deriviranih svojstava pokazalo je smanjenje udjela nisko razgranatih glikana, a povećanje visoko razgranatih glikana. Nadalje, smanjenje udjela digalaktoziliranih glikana i povećanje udjela trigalaktoziliranih i trisijaliniziranih glikana pronađeno je u bolesnika s T1DM. Udio glikana sa sržnom fukozom značajno je smanjen u bolesnika s T1DM, dok je udio oligomanoznih glikana značajno povećan. Ove promjene u glikozilaciji IgA upućuju na njegovu moguću ulogu u progresiji bolesti te na potrebu daljnjeg ispitivanja njegove prognostičke vrijednosti.Type 1 diabetes mellitus (T1DM) is a multifactorial, chronic, and autoimmune disease that results from a lack of endogenous insulin secretion from pancreatic β-cells. There are two markers currently available that indicate long-term diabetes control – HbA1c and fructosamine, but both have their limitations. Therefore, there is a great need for a marker that would show the longitudinal progression of T1DM in a more precise way. Changes in the N-glycosylation profile of total plasma proteins and immunoglobulin G in many studies have proven to be a potential prognostic, diagnostic and therapeutic marker of various diseases, especially those of an inflammatory nature, such as T1DM. Glycosylation of immunoglobulin A in various diseases has generally been less studied, and only a few years ago, intensive research into the role of its glycosylation in T1DM began. The aim of this study is to identify changes in IgA N-glycosylation in the population of adult patients with T1DM and compare them with healthy individuals. Glycan analysis was done by ultra performance liquid chromatography based on hydrophilic interactions. In this thesis, it was discovered that in adult subjects diagnosed with T1DM there is a statistically significant change in the proportion of glycan structures GP2, GP4, GP5, GP7, GP13, GP14, GP17, GP19, GP21, GP24, GP25, GP27 and GP29. A more detailed study of the derived traits showed a decrease in the proportion of low-branched glycans, and an increase in highly branched glycans. Furthermore, a reduction in the proportion of digalactosylated glycans and an increase in the proportion of trigalactosylated and trisialinised glycans is found in T1DM patients. The proportion of glycans with core fucose was significantly reduced in T1DM patients, while the proportion of high mannose glycans was significantly increased. These changes in IgA glycosylation indicate that it has a possible role in the disease progression and the need for further examination of its prognostic value

Renaissance of the Hofmann-Löffler-Freytag Reaction – Development of C–H Functionalisation Strategies Based on Green Chemistry Principles

Hofmann-Löffler-Freytagova reakcija otkrivena je krajem 19. stoljeća, a munjeviti razvoj događa se posljednjih 20 godina. Primjenjuje se za stvaranje C−N veze na nesupstituiranim C−H pozicijama te za uvođenje pirolidinskih i piperidinskih prstenova na ekološki prihvatljiv način, bez upotrebe skupih metalnih katalizatora i uz vrlo učinkovite sinteze. U ovom pregledu prikazat će se računalne i eksperimentalne studije koje pokazuju fleksibilnost i mogućnosti optimizacije navedene metode s ciljem povećanja ekonomičnosti i smanjenja količine otpadnih tvari, po principima zelene kemije. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.Increased demand for drugs has promoted the pharmaceutical and chemical industries as the most dynamic industries of the 21st century. By using the Hofmann-Löffler-Freytag (HLF) reaction, the modification of pharmacologically active substances and biologically important compounds can be achieved in an environmentally friendly manner by highly efficient syntheses. This reaction enables the formation of new compounds according to the principles of green chemistry, without expensive metal catalysts. Numerous computational and experimental studies have shown exceptional flexibility and the possibility of optimising this method in order to increase the economy and reduce the amount of waste generated as by-products of synthetic processes. However, the mechanism of this reaction is yet to be elucidated sufficiently, and further experiments are necessary in order to determine the thermodynamic and kinetic parameters that control and guide the HLF reaction. It is necessary to determine the influence of substituents and solvents on 1,5-HAT or 1,6-HAT regioselectivity, and to recognise the mechanism responsible for switching between the radical and ionic mechanism of the reaction. This work is licensed under a Creative Commons Attribution 4.0 International License

N-glycosylation of immunoglobulin A in children and adults with type 1 diabetes mellitus

Aims: To identify N-glycan structures on immunoglobulin A related to type 1 diabetes mellitus among children at the disease onset and adults with type 1 diabetes mellitus. Methods: Human polyclonal IgA N-glycans were profiled using hydrophilic interaction ultra performance liquid chromatography in two cohorts. The first cohort consisted of 62 children at the onset of type 1 diabetes mellitus and 86 of their healthy siblings. The second cohort contained 84 adults with the disease and 84 controls. Associations between N-glycans and type 1 diabetes mellitus were tested using linear mixed model for the paediatric cohort, or general linear model for the adult cohort. False discovery rate was controlled by Benjamini-Hochberg method modified by Li and Ji. Results: In children, an increase in a single oligomannose N-glycan was associated with type 1 diabetes mellitus (B = 0.529, p = 0.0067). N-glycome of the adults displayed increased branching (B = 0.466, p = 0.0052), trigalactosylation (B = 0.466, p = 0.0052), trisialylation (B = 0.629, p < 0.001), and mannosylation (B = 0.604, p < 0.001). The strongest association with the disease was a decrease in immunoglobulin A core fucosylation (B = −0.900, p < 0.001). Conclusions: Changes in immunoglobulin N-glycosylation patterns in type 1 diabetes point to disruptions in immunoglobulin A catabolism and dysregulated inflammatory capabilities of the antibody, potentially impacting immune responses and inflammation