Correlates of metabolic syndrome in people with chronic spinal cord injury

PURPOSE

We aimed at identifying clinical risk factors or early markers of metabolic syndrome (MetS) in people with spinal cord injury (SCI) that would facilitate a timely diagnosis and implementation of preventive/therapeutic strategies.

METHODS

One hundred sixty-eight individuals with chronic (> 1 year) SCI underwent clinical and biochemical evaluations. MetS was diagnosed according to modified criteria of the International Diabetes Federation validated in people with SCI. Wilcoxon rank-sum test and χ2 test were used to compare variables between groups with and without MetS. Multiple logistic regression analysis was performed to reveal independent associations with MetS among variables selected by univariate linear regression analyses.

RESULTS

MetS was diagnosed in 56 of 132 men (42.4%) and 17 of 36 women (47.2%). At univariate regression analyses, putative predictors of MetS were an older age, a higher number of comorbidities, a lower insulin-sensitivity, the presence and intensity of pain, a shorter injury duration, a poorer leisure time physical activity (LTPA) and an incomplete motor injury. At the multiple logistic regression analysis, a significant independent association with MetS only persisted for a poorer LTPA in hours/week (OR: 0.880, 95% CI 0.770, 0.990) and more severe pain symptoms as assessed by the numeral rating scale (OR: 1.353, 95% CI 1.085, 1.793).

CONCLUSION

In people with chronic SCI, intense pain symptoms and poor LTPA may indicate a high likelihood of MetS, regardless of age, SCI duration, motor disability degree, insulin-sensitivity and comorbidities.

Advanced Glycation end Products: Specific Fluorescence Changes of Pentosidine-Like Compounds during Short Daily Hemodialysis

Background

Advanced glycation end products (AGE) accumulate in uremia and represent an important etiopathogenetic cause of morbidity in dialyzed patients. Conventional hemodialysis treatment seems to be ineffective in lowering AGE levels. We wished to investigate whether daily hemodialysis (DHD), a treatment that seems to result in better clinical condition in end-stage renal disease patients, is effective in the reduction of these compounds.

Methods

We evaluated 10 non-diabetic patients on standard hemodialysis (SHD = 3 × 4h/week) for more than 6 months by a crossover study. These patients were assigned randomly to 6 months of DHD (6 × 2h/week) or 6 months of SHD. Then, they were switched to 6 months of the alternative treatment. At the end of these two periods, we studied pentosidine-like AGE compounds by measuring the total fluorescence at a wavelength characteristic for these substances: Ex: 335nm / Em:385nm; we also measured protein-linked pentosidine at the same time points. Finally, we determined the AGE-related total fluorescence in the deproteinized serum of 13 uremic patients on peritoneal dialysis (CAPD) and of 10 healthy controls.

Results

Pre-HD AGE-related total fluorescence obtained after 6 months of DHD was significantly lower than that obtained with standard HD (DHD = 201.3 ± 36.4 AU/ml vs. SHD = 267.5 ± 141.4 AU/ml, p=0.03). The extraction rate per minute of dialysis was slightly, but not significantly higher during DHD than SHD (0.29 ± 0.11% vs. 0.23 ± 0.04, p = 0.07). AGE-related total fluorescence pre-HD values in patients treated by SHD and DHD were about 20-fold higher than in control subjects. They did not differ from CAPD patients. The pre-dialysis level of protein-linked pentosidine was significantly lower in DHD than in SHD (DHD = 16.12 ± 4.71 pmol/mg protein, SHD = 22.64 ± 6.86 pmol/mg protein, p < 0.01).

Conclusions

DHD showed a reduction in AGE-related total fluorescence, although the mean value remained higher than in control subjects. DHD is also accompanied by a decrease in protein-linked pentosidine.

Photophysical and structural characterisation of in situ formed quantum dots

Conjugated polymer-semiconductor quantum dot (QD) composites are attracting increasing attention due to the complementary properties of the two classes of materials. We report a convenient method for in situ formation of QDs, and explore the conditions required for light emission of nanocomposite blends. In particular we explore the properties of nanocomposites of the blue emitting polymer poly[9,9-bis(3,5-di-tert-butylphenyl)-9H-fluorene] together with cadmium sulphide (CdS) and cadmium selenide (CdSe) precursors. We show the formation of emissive quantum dots of CdSe from thermally decomposed precursor. The dots are formed inside the polymer matrix and have a photoluminescence quantum yield of 7.5%. Our results show the importance of appropriate energy level alignment, and are relevant to the application of organic-inorganic systems in optoelectronic devices.

CdS and ZnS Nanoparticles Growth in Different Reaction Media: Synthesis and Characterization

In this work we report on the growth of cadmium sulfide and zinc sulfide nanocrystals by thermolysis, starting from a metal thiolate in a (i) solventless way, (ii) by a novel route in tryoctilphosphine oxide (TOPO), and (iii) by direct synthesis in a polystyrene matrix. The x-ray diffraction (XRD) and transmission electron microscopy (TEM) show that the nanocrystals fabricated by the different methods are under optimized growth conditions single crystals of zincblende structure and of regular spherical shape. The average size was estimated to be between 2.0-3.0 nm with a size dispersion that depends on the synthesis route and is in the range between 10% and 20%. The XPS results indicate that for the nanoparticles obtained via solventless strategy the sulfur is present both as bonded to the metal atom and to the organic residue, while in the TOPO synthesized nanoparticles the sulfur signal has only one component associated to the metal-sulfide bond. The photoluminescence spectroscopy (PL) analysis of CdS crystals clearly evidences the typical emissions of nanosized zincblende CdS monocrystalline particles. Furthermore, the optical spectroscopy data indicate that the size distribution of the Cdsulfide - TOPO nanoparticles seems to be generally larger than that ones grown directly in polymer matrix. For all the CdS samples, the metal-sulfide nanocrystals exhibit a trap-related radiative transition at about 2eV that can be attributed to the hole-electron recombination at particle surface defect-center.

Principal component analysis of some oxidative stress parameters and their relationships in hemodialytic and transplanted patients

BACKGROUND

Oxidative stress profoundly influences the biochemistry of proteins and many other molecules in tissues of uremic patients. In three different groups of uremic patients, the concentrations of the free and bound pentosidine and low-molecular-weight-advanced glycoxydation end products (LMW-AGEs), carbonyls (LMW-C), advanced oxidation protein products (AOPP) and the total antioxidant power of serum were studied in order to determine the relationships between these factors in hemodialytic and transplanted patients.

PATIENTS AND METHODS

The above-mentioned parameters were determined in 10 subjects who were currently in hemodialysis (HD) treatment, 10 kidney transplanted patients with chronic renal failure (Tx-CRF), 10 kidney transplanted patients with normal renal function (Tx-N) and 10 healthy subjects (Ctr). The data matrix (40x7) was analyzed using the principal component analysis (PCA).

RESULTS

AGEs, carbonyls and AOPP were strongly correlated, while the total antioxidative serum capacity was not related to the other oxidative stress parameters. All the oxidative stress-related parameter values (AGEs, AOPP and LMW-C) in the Tx patients were similar to those of the control group, but were higher in the patients with chronic renal failure.

CONCLUSIONS

The correlation between early and advanced oxidative stress markers indicates that reactive oxygen species are involved in a common step in the mechanism of protein modification in all the patient examined. The relationships between carbonyls and AGEs (free, bound pentosidine and LMW-AGEs) support the hypothesis of "carbonyl stress". The common mechanism of the formation of oxidation products in healthy and diseased subject suggests their role of detoxification within kidney function. The total antioxidant power of the serum is not related to the other parameters, which indicates a possible role of molecule interfering.

Normalization of oxidative stress parameters after kidney transplant is secondary to full recovery of renal function

BACKGROUND

It is well-known that hemodialysis patients experience increased oxidative stress, which is believed to cause numerous uremia-related complications. Retention of water-soluble toxins as well as protein-bound toxins is due to renal failure. Kidney transplantation restores, at least partially, the fundamental processes of glomerular filtration which eliminates toxic solutes. The aim of this study was to determine the levels of several different glycoxydative stress-related parameters after kidney transplantation.

PATIENTS AND METHODS

A cross-sectional study was carried out on 30 subjects: 10 kidney-transplanted patients with chronic renal failure (Tx-CRF), 10 kidney-transplanted patients with normal renal function (Tx-N) and 10 controls (Ctr). The groups were comparable with respect to age and gender. The following glycoxydative stress markers were determined by HPLC analysis: albumin-bound and free pentosidine, low-molecular weight-advanced glycation end products (LMW-AGEs), advanced oxidation protein products (AOPP) and low-molecular weight carbonyls (LMW-C). The total antioxidant serum capacity was monitored by measuring both the ferric reducing/antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC).

RESULTS

With respect to the controls, the Tx-CRF patients had higher levels of pentosidine (2.66 +/- 0.98 vs 1.45 +/- 1.1 pmol/mg), LMW-AGE (47.55 +/- 39.74 vs 15.45 +/- 6.39 a.u./ml), and AOPP (6.71 +/- 0.78 vs 4.81 +/- 0.32 a.u./mg) while Tx patients with normal kidney function had levels of these compounds that were comparable to the controls, except for the LMW-AGEs which were higher. Levels of LMW-AGEs, pentosidine, LMW-C and AOPP were inversely correlated to creatinine clearance. The total antioxidation serum capacity was paradoxically higher in Tx patients than in the controls, regardless of kidney function. FRAP as well as ORAC, were correlated to uric acid (r = 0.62, p < 0.001; r = 0.54, p < 0.01).

CONCLUSIONS

The reported data indicate that kidney transplantation seems to restore a nearly normal level of glycoxidative stress markers, but a complete remission is only possible when the renal function is normal. An increase of total antioxidant power of serum in transplanted patients was reported, as probable effect of uric acid high levels.

High frequency percussive ventilation (HFPV). Case reports

Treatment of acute respiratory failure is still a hot issue in intensive care everyday practice: in the last few years high frequency ventilation techniques have been employed as a therapy for adult respiratory distress syndrome (ARDS) and acute respiratory failure (ARF). We applied high frequency percussive ventilation (HFPV) to 3 patients affected by ARDS or ARF, who did not improve after 24 hours of conventional mechanical ventilation (CMV). All our patient underwent 12 hours of HFPV, and showed an improvement of both respiratory exchange and radiological imaging. Even if the pathogenesis of ARF was quite different, in all patient we registered a good response and no complications.

Advanced glycation end products: specific fluorescence changes of pentosidine-like compounds during short daily hemodialysis

BACKGROUND

Advanced glycation end products (AGE) accumulate in uremia and represent an important etiopathogenetic cause of morbidity in dialyzed patients. Conventional hemodialysis treatment seems to be ineffective in lowering AGE levels. We wished to investigate whether daily hemodialysis (DHD), a treatment that seems to result in better clinical condition in end-stage renal disease patients, is effective in the reduction of these compounds.

METHODS

We evaluated 10 non-diabetic patients on standard hemodialysis (SHD = 3 x 4 h/week) for more than 6 months by a crossover study. These patients were assigned randomly to 6 months of DHD (6 x 2 h/week) or 6 months of SHD. Then, they were switched to 6 months of the alternative treatment. At the end of these two periods, we studied pentosidine-like AGE compounds by measuring the total fluorescence at a wavelength characteristic for these substances: Ex: 335nm/Em:385nm; we also measured protein-linked pentosidine at the same time points. Finally, we determined the AGE-related total fluorescence in the deproteinized serum of 13 uremic patients on peritoneal dialysis (CAPD) and of 10 healthy controls.

RESULTS

Pre-HD AGE-related total fluorescence obtained after 6 months of DHD was significantly lower than that obtained with standard HD (DHD = 201.3 +/- 36.4 AU/ml vs. SHD = 267.5 +/- 141.4 AU/ml, p = 0.03). The extraction rate per minute of dialysis was slightly, but not significantly higher during DHD than SHD (0.29 +/- 0.11% vs. 0.23 +/- 0.04, p = 0.07). AGE-related total fluorescence pre-HD values in patients treated by SHD and DHD were about 20-fold higher than in control subjects. They did not differ from CAPD patients. The pre-dialysis level of protein-linked pentosidine was significantly lower in DHD than in SHD (DHD = 16.12 +/- 4.71 pmol/mg protein, SHD = 22.64 +/- 6.86 pmol/mg protein, p < 0.01).

CONCLUSIONS

DHD showed a reduction in AGE-related total fluorescence, although the mean value remained higher than in control subjects. DHD is also accompanied by a decrease in protein-linked pentosidine.

[Propofol and remifentanil in day surgery]

BACKGROUND

AIM OF THE STUDY

to compare AG versus MAC using propofol & remifentanil in a day surgery setting evaluating intra and postoperative clinical conditions and emergence times.

METHODS

Propofol and remifentanil, either for general anesthesia (AG) then conscious sedation (MAC), have been administered to 218 patients undergoing mainly plastic or proctologic surgery as day hospital. AG was induced with propofol 1.5-2 mg/kg followed by a continuous infusion of 10 mg/kg/h and remifentanil infused at 10 micrograms/kg/h; MAC was started with propofol 3 mg/kg/h and remifentanil 4-5 micrograms/kg/h; during the maintenance phase of both AG and MAC, infusion rates of both drugs were adjusted according to clinical needs. Diazepam (0.05-0.06 mg/kg) and/or midazolam (2-3 mg) were given as premedication or coinduction as necessary. All patients received field infiltration with local anesthetics (lidocaine or mepivacaine); patients under GA were artificially ventilated with O2/air through IOT or LMA. Surgical and anesthesiological data were collected on specially designed records, with special attention to time intervals between anesthesia (FA) and surgery (FC) end and eyes opening (EO), orientation (OR), return of spontaneous breathing (SR), extubation (EST), sitting (SED), walking (CAMM), dressing (VEST) and discharge (DIM); data were analyzed with parametric and non parametric analysis of variance.

RESULTS

All emergence intervals were longer under AG than under MAC: the earlier in the range of 4-5 vs 0.5-1 min; for the late intervals; FA-SED 24 +/- 18 vs 15 +/- 8, FA-PIED 65 +/- 48 vs 34 +/- 17, FA-VEST 69 +/- 58 vs 33 +/- 17, FA-CAMM 68 +/- 42 vs 39 +/- 19. Discharge times (83 +/- 67 vs 73 +/- 60) were similar between the two groups. Drugs consumption under AG were roughly double than under MAC; total dose infused of propofol (mg/kg/min) 0.118 +/- 0.044 vs 0.06 +/- 0.036; total dose of remifentanil (microgram/kg/min): 0.106 +/- 0.049 vs 0.066 +/- 0.027. AG resulted in a higher % incidence of intraoperative hypotension and bradycardia: hypotension 61.7 vs 25.7 and bradycardia 30.3 vs 12.4. SaO2 decreased more commonly during MAC than AG (20.9% vs 10.1); intraoperative itching was referred in 20% of MAC patients. Conversions rate from MAC to AG was 2.8%. Psychomotor agitation was more frequent following AG (14%) than MAC (2%); nausea (1%), vomiting, shivering (12%), headache (2%), ortostatic hypotension (2%) were similar between the two groups. Diazepam and/or midazolam caused a significant prolongation of recovery intervals, for both AG and MAC with a mean delay of the order of 100-200%.

CONCLUSIONS

Propofol- remifentanil gave excellent conditions for a wide variety of day surgery procedures, offering good anesthesia with quick emergence; the addition of bdz, even at low doses, prolongs significantly discharge times.

Effective doses of cisatracurium. Potentiation by sevoflurane and increasing requirements with age

BACKGROUND

The aim of the study was to investigate whether or not sevoflurane at different concentrations influenced the ED(effective dose) 50, 90 and 95 of cisatracurium and whether there is any relationship with age.

METHODS

Individual dose response curves for cisatracurium were constructed in 80 consecutive patients randomly assigned to four groups: group 1 TIVA with fentanyl and propofol; group 2, 3 and 4 sevoflurane 1, 1.5, 2 MAC respectively, MAC age adjusted and with N2O 65%. Patients were premedicated with diazepam and induction accomplished with fentanyl (1.5-2 micrograms/kg) and propofol (1.5-2 mg/kg); following intubation with succinylcholine (0.4 mg/kg), TIVA or sevoflurane at the desired MAC was maintained until equilibration occurred and then cisatracurium administered in 8-10 micrograms/kg boluses until the attainment of ED95. Neuromuscular monitoring utilized TOF stimulation and ratio evaluation between Ist twitch of the train and basal twitch (T1/Tc) and continuous recording of accelerometry (Tof-guard). Single dose response curves were analyzed with sigmoid equations; the Eds and other parameter means were subjected to analysis of variance for parametric and non parametric data.

RESULTS

More boluses were required under TIVA and sevo 1 MAC anesthesia (8.3 and 7.1 vs 4.9 of sevo 1.5 and 2 MAC); maximal depression (94.95%) was reached more frequently with sevo, while under TIVA an average 90% depression only was obtained. Mean ED50 (microgram/kg) where 22 (sevo) vs 34 (TIVA): ED90 averaged 36 (sevo) vs 53 (TIVA); ED95 averaged 39 (sevo) vs 56 (TIVA), with significant differences (p < 0.05) between Eds obtained from TIVA group in comparison with sevoflurane groups, but without differences between averaged EDs obtained with different MAC values among sevoflurane groups. The investigation of the relationship between age and Eds demonstrated a linear regression for all groups considered together (p = 0.000) for all Eds (50, 90, 95).

CONCLUSIONS

In conclusion, the presence of MAC multiples of sevoflurane potentiated only slightly the dosages of cisatracurium and EDs linearly increase with age, particularly under sevoflurane anesthesia.

Thermal stability of protein secondary structure in Langmuir-Blodgett films

The temperature dependence of the secondary structure of photosynthetic reaction centres from Rhodobacter sphaeroides in solution and in Langmuir-Blodgett film was studied by circular dichroism. It was shown that the secondary structure of the protein was not affected in Langmuir-Blodgett films by heating up to 200 degrees C, while in solution it was completely lost at 55 degrees C. Molecular order rather than decreased hydration degree was held responsible.

Characterization of human and mouse c-fes cDNA clones and identification of the 5' end of the gene

cDNA clones of the human c-fes mRNA were isolated. Nucleotide analysis showed that c-fes mRNA contains a 2514 nucleotide open reading frame, which could encode for a 93 kDa protein, and both 5' and 3' v-fes nonhomologous sequences. Primer extension experiments confirmed that the longest isolated cDNAs are about the same length as the entire human c-fes mRNA. Sequence comparison between human c-fes cDNA and the corresponding genomic regions identified a 5' viral-non homologous exon (exon 1) located 491 bp upstream from the first v-fes homologous exon. The genomic region surrounding c-fes exon 1 contains a CpG island and acts as a promoter in vitro. Analysis of the 5' end of mouse c-fes cDNA suggested that the 5' human and mouse gene structure are similar.