A novel bioresponsive self-immolative spacer based on aza-quinone methide reactivity for the controlled release of thiols, phenols, amines, sulfonamides or amides.

A stimuli-sensitive linker is one of the indispensable components of prodrugs for cancer therapy as it covalently binds the drug and releases it upon external stimulation at the tumour site. Quinone methide elimination has been widely used as the key transformation to release drugs based on their nucleofugacity. The usual approach is to bind the drug to the linker as a carbamate and release it as a free amine after a self-immolative 1,6-elimination. Although this approach is very efficient, it is limited to amines (as carbamates), alcohols or phenols (as carbonates) or other acidic functional groups. We report here a self-immolative spacer capable of directly linking and releasing amines, phenols, thiols, sulfonamides and carboxyamides after a reductive stimulus. The spacer is based on the structure of (5-nitro-2-pyrrolyl)methanol (NPYM-OH), which was used for the direct alkylation of the functional groups mentioned above. The spacer is metabolically stable and has three indispensable sites for bioconjugation: the bioresponsive trigger, the conjugated 1,6 self-immolative system and a third arm suitable for conjugation with a carrier or other modifiers. Release was achieved by selective reduction of the nitro group over Fe/Pd nanoparticles (NPs) in a micellar aqueous environment (H2O/TPGS-750-M), or by NADH mediated nitroreductase activation. A DFT study demonstrates that, during the 1,6 elimination, the transition state formed from 5-aminopyrrole has a lower activation energy compared to other 5-membered heterocycles or p-aminobenzyl derivatives. The NPYM scaffold was validated by late-stage functionalisation of approved drugs such as celecoxib, colchicine, vorinostat or ciprofloxacin. A hypoxia-activated NPYM-based prodrug (HAP) derived from HDAC inhibitor ST7612AA1 was also produced, which was active in cancer cells under hypoxic conditions.

Blood biomonitoring of metals in subjects living near abandoned mining and active industrial areas.

A human blood biomonitoring campaign to detect the environmental exposure to metals (Cd, Cu, Cr, Mn, Pb and Zn) in 265 subjects was performed in the South-Western part of Sardinia (an Italian island) that is a particular area with a great history of coal and metal mining (Pb/Zn mainly) activities and large industrial structures (as metallurgy). Subjects living near the industrial plant area had geometric means (GM) of blood Cd (0.79 µg/l), Cu (971 µg/l), Mn (12.2 µg/l), and Pb (55.7 µg/l) significantly higher than controls (Cd, 0.47 µg/l; Cu, 900 µg/l; Mn 9.98 µg/l; Pb, 26.5 µg/l) and than people living nearby the past mining sites. Subjects living next to one dismissed mine were statistically higher in blood Cu (GM, 1,022 µg/l) and Pb (GM, 41.4 µg/l) concentrations than controls. No differences were observed in people living in the different mining sites, and this might be related to the decennial disclosure of mines and the adoption of environmental remediation programmes. Some interindividual variables influenced blood biomonitoring data, as smoke and age for Cd, gender for Cu, age, sex and alcohol for Pb, and age for Zn. Moreover, blood metal levels of the whole population were similar to reference values representative of the Sardinian population and acceptably safe according to currently available health guidelines.

Cytoskeletal proteins in the cerebrospinal fluid as biomarker of multiple sclerosis.

The axonal cytoskeleton is a finely organized system, essential for maintaining the integrity of the axon. Axonal degeneration is implicated in the pathogenesis of unremitting disability of multiple sclerosis (MS). Purpose of this study is to evaluate levels of cytoskeletal proteins such as neurofilament light protein (NFL), glial fibrillary acidic protein (GFAP), and ß-tubulin (ß-Tub) isoforms II and III in the cerebrospinal fluid (CSF) of MS patients and their correlation with MS clinical indices. CSF levels of cytoskeletal proteins were determined in 51 patients: 33 with MS and 18 with other neurological diseases (OND). NFL, GFAP and ß-Tub II proteins were significantly higher (p < 0.0001) in MS than in OND group; no significant difference (p > 0.05) was found between MS and OND with regard to ß-Tub III. Interestingly, levels of ß-Tub III and NFL were higher in progressive than in remitting MS forms; on the contrary, higher levels of ß-Tub II and GFAP were found in remitting MS forms. However, with the exception of ß-Tub III, all proteins tend to decrease their CSF levels concomitantly with the increasing disability (EDSS) score. Overall, our results might indicate ß-Tub II as a potential candidate for diagnostic and ß-Tub III as a possible prognostic biomarker of MS. Therefore, further analyses are legitimated and desirable.

Diet and nutrients are contributing factors that influence blood cadmium levels.

Studies suggested the intake of Cd from diet can be approximately equivalent to that from smoking. Moreover, a mutual metabolic influence between Cd and nutrients has been reported. The purpose of this study was to evaluate the relationship between blood cadmium concentration (BCdC) and food consumption, nutrients intake (Ca, Fe, Zn, vitamin C, and vitamin D), tobacco smoking, and some other variables (age, body mass index, and residence) in 243 adults living in the Italian island of Sardinia (Sassari Province). Specifically, we hypothesized that offal consumption contributes to Cd intakes and blood levels. The BCdC was quantified by graphite furnace atomic absorption spectrometry, and information on personal data was collected through questionnaires. Smoke significantly contributed to the BCdC (P < .001). Nonsmoker subjects who eat offal showed significantly higher BCdC (P = .04). Moreover, slightly higher BCdCs were also observed in nonsmoker subjects who eat rice, fish, and bread. The BCdC positively correlated with age of subjects (r = 0.144; P = .025) and offal daily intake in nonsmokers (r = 0.393; P < .001). The intake of Ca was negatively correlated (r = -0.281; P = .001) with the BCdC in females. The multiple linear regression analysis showed smoking > consumption of offal > body mass index ≈ age as the most important risk factors for the BCdC in the selected population.

Assessment of reference ranges for blood Cu, Mn, Se and Zn in a selected Italian population.

The reference ranges for blood Cu, Mn, Se and Zn of 215 adult subjects non-occupationally exposed and living in the Nuoro province (Sardinia, insular Italy) were assessed. Metals were determined by sector field inductively coupled plasma mass spectrometry after microwave-assisted acid digestion of blood. The blood reference ranges estimated as P5-P95 percentiles (geometric mean, GM) were 776-1495µg/L (1036µg/L) for Cu; 4.73-17.0µg/L (8.91µg/L) for Mn; 106-185µg/L (140µg/L) for Se and 4686-8585µg/L (6418µg/L) for Zn. These results were then stratified for sex, age, alcohol consumption, smoking habit and living area. The GM value of Cu was significantly higher in females (1127µg/L) than in males (957µg/L). Age, alcohol intake, smoking habit and residential area did not influence blood Cu. The GM of Mn was significantly higher in females (9.98µg/L) respect to males (8.01µg/L) and in drinkers (9.67µg/L) compared to non-drinkers (8.38µg/L). The other variables did not change the Mn data. Selenium concentrations did not differ significantly as a function of individuals factors. With reference to Zn, males had GM of 6804µg/L and females of 6031µg/L, and more blood Zn was found in subjects consuming alcohol (6618µg/L) respect to abstainers (6155µg/L). In addition, blood Zn was not affected by age, smoking habit and place of living.

Reference intervals for blood Cd and Pb in the general population of Sardinia (Italy).

The reference values (RVs) for blood Cd and Pb of 215 adult subjects non-occupationally exposed and living in Sardinia (insular Italy) were assessed. Age, sex, smoking, alcohol drinking and living area were used to stratify the reference group. After collection from volunteers, samples were acid digested in a microwave oven and metals were determined by sector field inductively coupled plasma mass spectrometry. The RVs expressed as 5th-95th percentiles (geometric mean, GM) were 0.24-1.82 µg/l (0.53 µg/l) for blood Cd and 13.2-87.3 µg/l (33.4 µg/l) for blood Pb. Females had GM levels of Cd (0.58 µg/l) higher than males (0.49 µg/l); subjects aged <40 years had less Cd (0.44 µg/l) than old subjects (>60 years; 0.56 µg/l); Cd in smokers (1.23 µg/l) was 3-times higher than in non-smokers (0.42 µg/l) and correlated with the number of cigarettes per day. The alcohol intake and place of living did not influence blood Cd. The GM values of blood Pb in males (44.4 µg/l) were higher than in females (24.7 µg/l); subjects less than 40 years-old (27.5 µg/l) showed lower Pb than elderly individuals (>60 years, 41.2 µg/l); drinkers (42.2 µg/l) had Pb 2-times higher than non-drinkers (24.4 µg/l). Blood Pb was not significantly affected by smoking and place of living. As revealed by multiple linear regression, the predictor variables were, in order of weight, smoke ≫ age for blood Cd levels, and sex = age ≫ alcohol for blood Pb levels.