Degradation kinetics of sugars (glucose and xylose), amino acids (proline and aspartic acid) and their binary mixtures in subcritical water: Effect of Maillard reaction

A systematic kinetic study was conducted in subcritical water medium in the temperature range from 150 to 200 °C for pure glucose, xylose, proline and aspartic acid as well as binary mixtures of sugars + amino acids to understand the reaction kinetics and interactions among biomass components and to discern the influence of Maillard reaction (MR) on the overall reaction kinetics. The main degradation products identified for glucose and xylose were the respective dehydration products, hydroxymethyl furfural and furfural, yielding an increasing solid residue with temperature (15.9 wt% at 200 °C) with an augmented heating value. The degradation of sugars and amino acids in binary systems was faster compared to pure compounds due to MR and the production of dehydration products was delayed when considering total sugar conversion. Higher relative reactivity in MR was observed for xylose over glucose showing also higher antioxidant activity.

Oligoclonal M bands and cervical spinal cord lesions predict early secondary progressive multiple sclerosis

Objective

To determine baseline cerebrospinal fluid and magnetic resonance imaging (MRI) variables at the onset of a clinically isolated syndrome (CIS) suggestive of multiple sclerosis (MS) that predict evolution to secondary progressive MS (SPMS).

Methods

276 CIS patients with a minimum follow-up of 10 years were studied. Baseline presence of oligoclonal IgG and IgM bands (OCGB and OCMB respectively); number of brain T2 lesions (B-T2L), brain gadolinium enhancement lesions (brain-GEL), cervical spinal cord T2 lesions (cSC-T2L); and fulfillment of 2017 McDonald criteria among other variables were collected.

Results

14 patients ended up with a non-MS condition. 138/276 CIS patients fulfilled 2017 McDonald criteria. Mean age was 32.4 years, 185 female. 227 received treatment, 95 as CIS. After a mean follow-up of 12 years, 36 patients developed SPMS. Conversion to SPMS was associated with OCGB (p = 0.02), OCMB (p = 0.0001); ≥ 9 B-T2L (p = 0.03), brain-GEL (p = 0.03), and cSC-T2L (p = 0.03). However, after adjusting for sex, age, BT2L, brain-GEL, SC-T2, and OCMB status, only OCMB (HR 4.4, 1.9–10.6) and cSC-T2L (HR 2.2, 1.0–6.2) suggested an independent association with risk of conversion to SPMS. Patients with both risk factors had a HR of 6.12 (2.8–12.9).

Discussion

OCMB and SC-T2 lesions are potential independent predictors of conversion to SPMS.

Dyschromatopsia in multiple sclerosis reflects diffuse chronic neurodegeneration beyond anatomical landmarks

To formulate and validate a dyschromatopsia linear regression model in patients with multiple sclerosis (MS). 64 MS patients (50 to formulate the model and 14 for its validation) underwent neurological (Expanded Disability Status Scale, EDSS), color vision (Farnsworth D15 test), and peripapillary retinal nerve fiber layer (pRNFL) and retinal evaluation with spectral-domain optical coherence tomography (SD-OCT). Neuroradiological examination permitted to obtain brain parenchymal fraction (BPF) and cervical spinal cord volume (SC). Ophthalmic parameters were calculated as the average of both non-optic neuritis (ON) eyes, and in case the patient had previous ON, the value of the fellow non-ON eye was taken. The influence of sex, age, disease duration, and history of disease-modifying treatment (first- or second-line DMT) was tested as covariables that could influence color perception. Color confusion index (log CCI) correlated with pRNFL (r =  - 0.322, p = 0.009), ganglion cell layer (GCL, r =  - 0.321, p = 0.01), BPF (r =  - 0.287, p = 0.021), SC volume (r =  - 0.33, p = 0.008), patients' age (r = 0.417, p = 0.001), disease duration (r = 0.371, p = 0.003), and EDSS (r = 0.44, p = 0.001). The following CCI equation was obtained: log (CCI) = 0.316-0.224 BPF - 0.187 SC volume (mm3) + 0.226 age (years) + 0.012 disease duration (years) - 0.372 GCL (µm). CCI correlates with MS clinical and paraclinical established biomarkers suggesting chronic diffuse neurodegeneration in MS operates at brain, SC, and retina linking all three compartments. Color vision outcome can be calculated through the aforementioned variables for clinical and research purposes.

Design and Validation of an Expanded Disability Status Scale Model in Multiple Sclerosis

INTRODUCTION

We aimed to develop and validate an Expanded Disability Status Scale (EDSS) model through clinical, optical coherence tomography (OCT), and magnetic resonance imaging (MRI) measures.

METHODS

Sixty-four multiple sclerosis (MS) patients underwent peripapillary retinal nerve fiber layer and segmented macular layers evaluation through OCT (Spectralis, Heidelberg Engineering). Brain parenchymal fraction was quantified through Freesurfer, while cervical spinal cord (SC) volume was assessed manually guided by Spinal Cord Toolbox software analysis. EDSS, neuroradiological, and OCT assessment were carried out within 3 months. OCT parameters were calculated as the average of both nonoptic neuritis (ON) eyes, and in case the patient had previous ON, the value of the fellow non-ON eye was taken. Brain lesion volume, sex, age, disease duration, and history of disease-modifying treatment (1st or 2nd line disease-modifying treatments) were tested as covariables of the EDSS score.

RESULTS

EDSS values correlated with patient's age (r = 0.543, p = 0.001), SC volume (r = -0.301, p = 0.034), and ganglion cell layer (GCL, r = -0.354, p = 0.012). Using these correlations, an ordinal regression model to express probability of diverse EDSS scores were designed, the highest of which was the most probable (Nagelkerke R2 = 43.3%). Using EDSS cutoff point of 4.0 in a dichotomous model, compared to a cutoff of 2.0, permits the inclusion of GCL as a disability predictor, in addition to age and SC.

CONCLUSIONS

MS disability measured through EDSS is an age-dependent magnitude that is partly conditioned by SC and GCL. Further studies assessing paraclinical disability predictors are needed.

Magnetic resonance imaging and optical coherence tomography correlations in multiple sclerosis beyond anatomical landmarks

OBJECTIVE

To investigate multiple sclerosis (MS) optical coherence tomography (OCT) cross-sectional correlations with central nervous system (CNS) magnetic resonance imaging (MRI).

MATERIAL AND METHODS

Peripapillary retinal nerve fiber layer (pRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner (INL) and outer nuclear layer (ONL) of 54 relapsing remitting (RRMS) and 38 progressive (PMS, 9 primary and 29 secondary) patients were measured. With less than 3 months brain parenchymal fraction (BPF), spinal cord (SC), total gray matter (GM) and white matter volumes were calculated. Demographical and clinical data was compared according to the history of optic neuritis (HON). Relationships between OCT and MRI data were assessed using multivariable linear regression models, adjusting for age, gender and disease duration, taking into account HON and disease subtype.

RESULTS

Cerebellum (p = 0.008), pRNFL (p = 0.001), GCL (p = 0.001) and IPL (p = 0.001) were thinner, while INL was thicker (p = 0.02) if HON. SC correlated better with nasal pRNFL sectors in eyes with HON (all eyes: average pRNFL p = 0.035 η² = 0.213; N-pRNFL p = 0.04 η² = 0.36, NI-pRNFL p = 0.0001 η² = 0.484. RRMS eyes: N-pRNFL p = 0.034 η² = 0.348; NI-pRNFL p = 0.013 η² = 0.441), while it correlates with PMB (p = 0.032 η² = 0.144), GCL (p = 0.03 η² = 0.147) and IPL (p = 0.028 η² = 0.151) in eyes without HON regardless of the disease subtype. INL presented no microcystic macular oedema and was inversely associated with BPF (p = 0.029 η² = 0.363) and cerebellum (p = 0.015 η² = 0.428) in PMS eyes without HON.

CONCLUSIONS

OCT data correlates with different CNS compartments, even with no anatomical or functional linkage, serving as useful neurodegeneration and inflammation surrogate marker.

Structural changes of a protein extract from apple with polyphenoloxidase activity obtained by cationic reversed micellar extraction induced by high-pressure carbon dioxide and thermosonication

Polyphenoloxidase from apple was extracted and further concentrated by cationic reversed micellar extraction. Previous to reversed micellar extraction a crude protein extract was obtained using AG2-X8 as adsorbent of phenolic compounds and the detergent Triton X-100. Forward and backward extraction conditions were optimized by using dodecyl trimethyl ammonium bromide as surfactant in the organic phase. Optimization was carried out to obtain the highest value of PPO activity recovery and the purification fold at the different experimental conditions. Under the optimum extraction conditions, PPO activity recovery was 99% and purification fold reached a value of 17, showing that reversed micellar extraction was a good technique as a first step to concentrate on a targeted enzyme. After removing some impurities by centrifuge ultrafiltration, the protein extract with PPO activity was treated by pressurized carbon dioxide and thermosonication achieving residual PPO activity values of 16 ± 3 and 9 ± 1%, respectively. Quenching experiments by iodide performed in the non-treated extract and in the treated extracts revealed conformational changes of this protein fraction reflected in the greater exposure of the fluorophore to the quencher.

Effects of pork vs veal consumption on serum lipids in healthy subjects

AIMS

To analyse the influence of lean pork (P) and veal (V) consumption on the lipid profile of healthy subjects within the framework of a healthy diet comprising low levels of total fat (TF), saturated fatty acids (SFA) and cholesterol.

DESIGN

Double-crossover, randomized and controlled trial

SUBJECTS

44 healthy individuals (22 male and 22 female), recruited voluntarily from the University Complutense of Madrid. The weight and lipid profiles of these volunteers were normal and their dietary patterns were typical for people in our area.

INTERVENTIONS

The study comprised 4 phases: stabilisation phase (5 weeks), the participants followed their normal diet; second phase (6 weeks), half of the subjects, were randomised to lean pork or veal consumption, 150 g per day, for their main meal of the day; washout period (5 weeks) and final phase, which was the second phase of intervention (6 weeks). During the intervention stages, only the main meal of the day was taken in the Hospital. The rest of the subjects' diets consisted of different fortnightly menus designed in accordance with the recommendations of the Spanish Society of Arteriosclerosis (SEA).

RESULTS

After both stages of intervention had been completed, there was a mean reduction of 5.5% in low-density lipoprotein cholesterol. However, after each intervention there were no significant differences between those who had consumed P, 2.62 (0.55) mmol/L and those who had consumed V, 2.71 (0.47) mmol/L. No differences were observed in any of the other parameters between those who had consumed P and those who had consumed V.

CONCLUSIONS

Lean pork and veal produces similar effects on the lipid profiles of healthy subjects. Its consumption, as part of the saturated fat and cholesterol-controlled diet, could therefore be included in food guidelines, both for normal and therapeutic diets.

Prognostic value of the quantified expression of p185 in non-small cell lung cancer

BACKGROUND

We sought to assess the relationship between tissue concentration of erb -b-2 or neu oncogene-encoded protein (p185(neu)) with overall survival in patients with non-small cell lung cancer.

METHODS

Levels of protein p185(neu) were determined in 102 patients with the diagnosis of non-small cell lung cancer. Concentration of p185(neu) protein was determined by using enzyme immunoassay and evaluated by using several variables. The relative prognostic importance of this marker and its influence on other prognostic factors was evaluated by using the Cox regression model.

RESULTS

The mean p185(neu) value in these samples was 250 +/- 200 U/mg (95% confidence interval, 210-290). This distinguished two groups within the tumoral population: those with less than 350 U/mg and those with 350 U/mg or greater (80th percentile). Multivariable analysis established an independent prognostic value for protein p185(neu). Patients with p185(neu) values of the 80th percentile or greater had a risk of death that was 2.11-fold (95% confidence interval, 1.10-4.05) that of patients with values of less than 350 U/mg (P =.03), and increases in the neu oncogene of 100 U/mg increased the probability of death by 17% (P =.02; 95% confidence interval, 1.04-1.31).

CONCLUSION

This study shows that the p185(neu) expression is an objective and comparable variable for the assessment of phenotypic aggressivity in non-small cell lung cancer, and in the future, it could be included in daily clinical practice.

[Interobserver agreement in reading tuberculin tests]

BACKGROUND

The aim of the study was to evaluate the variability between four observers in the reading of the tuberculin test (TT).

METHODS

The study was carried out in the Centro de Salud Mendiguchía Carriche (Madrid) 72 subjects. By direct inspection, four observers read tuberculin determination (skin induration) independently in each subject. To assess variability, the kappa index (K) was calculated.

RESULTS

On considering the variable as a dichotomous one, with a cut-off point of 5 mm was 0.88; and of 10 mm, 0.78. Upon considering the index as qualitative in four categories the kappa index in 0 mm was 0.89; in 1-4 mm, 0.24; in 5-9 mm, 0.40 and greater than 9 mm, 0.79. In eight of the subjects studied, the variability observed in reading the test had conditioned further different clinico-epidemiologic attitudes.

CONCLUSIONS

The degree of concordance when reading TT is significantly lower at the 1-4 mm and 5-9 mm intervals.

[Somatotropin secretion during sleep in 60 cases of growth retardation in children]

A study of nocturnal somatotropic secretion with sleep polygraphic recording was performed in 60 children, aged 1 to 18 years and presenting with growth retardation greater than or equal to -2SD. GH secretion was analysed according to the peak value, the number of peaks greater than 5 ng/ml and the integrated concentration (surface under the curve divided by the duration of the test). The children were studied in four groups according to the responses to pharmacologic stimulation tests: a normal group (n = 7), a group with complete somatotropic deficiency (n = 4), a group with partial somatotropic deficiency (n = 39) and a group with dissociated responses (n = 12). Results are concordant between sleep secretion and pharmacologic tests in the first two groups. On the contrary, in the two last, the study of the sleep secretion allows to differentiate children with hyposecretion ("true partial deficiencies") from children with normal secretion ("false partial deficiencies") or abnormal responders). In other respects, correlations between LH maximum peak and stages of sleep are analysed. The maximum peak was observed in only 33.9% of cases during stage IV, 21.5% of cases during stages I, II, III, in 19.6% of cases during wakefulness and in 25% of cases during paradoxical stage. The maximum peak was observed in only 48% of cases during the first cycle of sleep and in 52% of cases during the other cycles. These results show that the correlation between maximum peak, stage IV and first cycle of sleep is not absolute.

Comparison of spontaneous growth hormone secretion during daytime and sleep in children with short stature

The authors compared diurnal growth hormone (GH) secretion with GH secretion during sleep in 24 children with delayed growth. In group I (children with normal response to provocative tests), the level of daytime secretion was lower than that of nocturnal secretion. In 3 of 9 cases, daytime secretion was abnormal, whereas nocturnal secretion was normal. In 2 cases, both diurnal and nocturnal secretion were abnormal, but response to provocative stimuli was normal. In group II (children with a false partial GH deficiency, i.e. with inadequate response to provocative tests, GH peak less than 11 ng/ml and normal nocturnal secretion), the results were comparable with those of group I, with extremely low diurnal secretion in 6 of 9 cases. In group III (children presenting true partial GH deficiency, i.e. GH less than 11 ng/ml in response to provocative tests together with abnormal nocturnal secretion), both diurnal and nocturnal GH secretion were insufficient, with nonexistent diurnal secretion in 5 of 6 cases. Diurnal secretion does not seem to be a reliable indicator of 24-hour spontaneous secretion.

[Results of treatment with growth hormone. Apropos of 31 cases of pituitary insufficiency]

The results of treatment with human growth hormone in 31 children with hypopituitarism are reported. 19 boys and 12 girls were treated for several years, six years in three instances. Pituitary insufficiency was idiopathic in 23 cases (isolated in 11 and associated with other deficiencies in 12) and secondary in 8 cases. The mean statural gain during the first year of treatment was 6.3 +/- 2.2 cm with a mean dosage of 9.3 +/- 4 mg/kg/year. The parameters which have the most bearing on statural gain during the first year are: dosage (p less than 0.001) which must be at least equal to 8 mg/kg/year, bone age and chronologic age. In subsequent years statural gain is less significant and seems to be dependent upon the same parameters.