An HPLC method for the quantification of sterols in edible seaweeds

This study presents an HPLC method for the quantification of sterols in edible seaweeds. Sterols were identified by HPLC/mass spectrometry (HPLC-MS) in positive APCI mode. The samples were saponified by refluxing with 1 m ethanolic KOH, and the non-saponifiable fraction was extracted with hexane. Sterols were quantified by HPLC with UV detection (HPLC-UV), on a 15 x 0.4 cm Kromasil 100 C(18) 5 micro m column (mobile phase 30:70 v/v methanol:acetonitrile; fl ow rate 1.2 mL/min; column temperature 30 degrees C; detection wavelength 205 nm). Method repeatability for fucosterol was good (coefficient of variation 2.4%). Sterol contents were determined in canned or dried brown seaweeds (Himanthalia elongata, Undaria pinnatifida, Laminaria ochroleuca) and red seaweeds (Palmaria sp., Porphyra sp.). The predominant sterol was fucosterol in brown seaweeds (83-97% of total sterol content; 662-2320 micro g/g dry weight), and desmosterol in red seaweeds (87-93% of total sterol content; 187-337 micro g/g dry weight).

High-performance liquid chromatographic determination of alpha-tocopherol in macroalgae

A high-performance liquid chromatographic (HPLC) method for the microscale determination of alpha-tocopherol in macroalgae is reported. The method includes microscale saponification and extraction with n-hexane. The presence of alpha-tocopherol in macroalgae samples was confirmed by HPLC-MS. Alpha-tocopherol levels as determined in samples by HPLC with UV and fluorescence detection did not differ significantly; however, fluorescence detection has a higher sensitivity (detection limit 10.4 ng/ml, vs. 104 ng/ml with UV detection), as well as good precision (relative standard deviation 1.81%) and recovery (94.3%). Fluorescence detection is also faster. We used this method to determine the alpha-tocopherol contents of four commercial macroalgae products from northwest Spain as part of nutritional studies in dehydrated Himanthalia elongata and Laminaria ochroleuca, and also in canned Himanthalia elongata and Saccorhiza polychides.

Determination of folates in seaweeds by high-performance liquid chromatography

A reversed-phase high-performance liquid chromatography (HPLC) method, with a combination of fluorescence and ultraviolet detectors, to determine the folate forms present in commercial macroalgae products form northwest Spain as part of nutritional studies in dehydrated and canned seaweeds is reported. The method includes extraction of folates from seaweed by heat treatment, deconjugation of folate polyglutamates by incubation with hog kidney conjugase and purification by solid-phase extraction (SPE) with strong anion-exchange (SAX) cartridges. Separation was achieved with a Tracer Extrasil ODS 5 microm 25 cm x 0.4 cm column using acetonitrile and potassium phosphate buffer (pH 2.21 as mobile phase. Good results were obtained with respect to repeatability (relative standard deviation (R.S.D.) < or = 4.12%) and recovery (> or = 90.80%). The amount of folate (as folic acid) in the six species ranged from 61.4 to 161.6 microg per 100 g dry mass. In all the seaweeds studied (Himanthalia elongata, Laminaria ochroleuca, Palmaria spp., Undaria pinnatifida and Porphyra spp. and Saccorhiza polychides) the single most abundant form is 5-CH3-H4-folate, except Porphyra and Himanthalia.

Determination of hexanal as indicator of the lipidic oxidation state in potato crisps using gas chromatography and high-performance liquid chromatography

Hexanal (an oxidative state indicator) formed in the headspace of potato crisps during storage was evaluated using two different procedures. First, solid-phase microextraction, an innovative sampling preparation methodology was used. It consisted on the absorption of analytes directly from samples and subsequent thermal desorption on the gas chromatograph (GC) injector. Then, a reversed-phase high-performance liquid chromatographic technique (HPLC) was employed to quantify hexanal in the form of 2,4-dinitrophenylhydrazone derivative. Methods were evaluated in what concerns to validation parameters such as linearity, repeatibility and detection limit. GC (LOD = 1 ng/ml) method resulted in more sensitive method than HPLC (LOD = 9 ng/ml). The most suitable technique for hexanal measurement was selected.

Simultaneous Determination of Thiamine and Riboflavin in Edible Marine Seaweeds by High-Performance Liquid Chromatography

This study presents a high-performance liquid chromatography (HPLC) method for simultaneous determination of thiamine and riboflavin and the results of its application to a number of edible seaweeds that are sampled in dried form (Himanthalia elongata, Laminaria ochroleuca, Undaria pinnatifida, Palmaria sp., and Porphyra sp.) or as canned food (H. elongata and Saccorhiza polyschides). Samples are prepared by acid and enzymatic hydrolysis. Optimized conditions for reversed-phase HPLC with fluorescence detection are as follow: column, Kromasil 100 C18; column temperature, 35 degrees C; mobile phase, a 72:28 (v/v) mixture of 0.005 M ammonium acetate (pH 6.7)-methanol; and flow rate, 1.35 mL/min. With these conditions, recovery is 95.52% for thiamine and 90.08% for riboflavin, and the method precision (relative standard deviation) is 2.66% for thiamine and 2.21% for riboflavin. On a dry weight basis, thiamine contents range from 0.14 microg/g in dried H. elongata to 2.02 microg/g in dried Porphyra and riboflavin contents from 0.31 microg/g in canned H. elongata to 6.15 microg/g in dried Porphyra.

Determination of the uronic acid composition of seaweed dietary fibre by HPLC

A high-performance liquid chromatographic (HPLC) method is described for determination of the ratio of beta-d-mannuronic acid to alpha-l-guluronic acid (M/G ratio) in dietary fibre of edible seaweeds. Total dietary fibre (TDF) content was determined gravimetrically. The TDF fraction was hydrolysed with 12 m and 1 m H(2)SO(4), then neutralized with AG 4 x 4 resin. The uronic acids were separated in a Tracer Extrasil SAX 5 micro m column (25 cm x 4 mm) at 35 degrees C, with 2 mm KH(2)PO(4) containing 5% methanol as mobile phase at a fl ow rate of 1.5 mL/min. The detection wavelength was UV 210 nm. The chromatographic identifications of beta-d-mannuronic acid and alpha-l-guluronic acid were confirmed by liquid chromatography-mass spectrometry (LC-MS). The method precision was 1.4% for beta-d-mannuronic acid and 3.5% for alpha-l-guluronic acid. The method was used to determine M/G ratio in canned seaweeds (Saccorhiza polyschides and Himanthalia elongata) and in dried seaweeds (H. elongata, Laminaria ochroleuca, Undaria pinnatifida, Palmaria sp. and Porphyra sp.).

Separation of phospholipid classes in sea urchin, paracentrotus lividus by high-performance liquid chromatography

A simple high-performance liquid chromatography (HPLC) method for determination of major phospholipid classes in sea urchin Paracentrotus lividus is described. The separation was performed on a Tracer Extrasil SI 5 microm 25 x 0.4 cm column and an isocratic mobile phase of acetonitrile-methanol 85%-phosphoric acid (50:50:1.8, v/v). The HPLC method utilizes UV detection at 205 nm. Five phospholipids were identified and quantified: phosphatidylinositol (PI), phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylcholine (PC) and sphingomyelin (SM). Fresh and canned samples were analyzed. Student's t-test showed no significant difference (P < or = 0.05) between the mean phospholipid contents of raw and canned sea urchin.

Determination of volatile components in fresh, frozen, and freeze-dried Padrón-type peppers by gas chromatography-mass spectrometry using dynamic headspace sampling and microwave desorption

"Padrón-type" peppers are a small variety of Capsicum annuum cultivated mainly in Galicia, Spain. To compare the effects of freezing and freeze-drying on the volatile components of Padrón-type peppers, preserved samples are analyzed by means of dynamic headspace sampling on an adsorbent followed by microwave desorption into a gas chromatograph equipped with a mass spectrometric detector. Sixty-five compounds are identified, including hydrocarbons, terpenes, alcohols, phenols, ethers, aldehydes, ketones, esters, pyrroles, pyrazines, and sulfurous compounds. Fresh whole, homogenized, and freeze-dried peppers have characteristic volatile-component profiles, whereas frozen peppers have a highly variable volatile-component profile.

Electrophysiological subtypes and associated prognosis factors of Mexican adults diagnosed with Guillain-Barré syndrome, a single center experience

BACKGROUND

The clinical characteristics of electrophysiological subtypes and prognostic factors of Mexican adults diagnosed with Guillain-Barré Syndrome (GBS) have not been described.

MATERIALS AND METHODS

A single center, ambispective, cohort study was performed (2015-2019). GBS was defined following the Asbury and Cornblath criteria. Electrodiagnosis was made according to Hadden criteria. Clinical, biochemical and electrodiagnostic parameters were described, compared and analyzed using a multivariate model. Only patients who completed a 3-month follow-up were included.

RESULTS

137 GBS patients (92 males; mean age 46.6 ± 16.6).132 (96.3%) underwent an electrodiagnostic assessment.68 (51.5%) were classified as axonal GBS, with further classified into two groups: acute motor axonal neuropathy (AMAN) 45.4%, and acute motor and sensory axonal neuropathy (AMSAN) 8,6%. The following characteristics were lower in the AMAN group: Medical Research Counsel sumscore (MRC) 30.1 ± 16.3 vs 36.4 ± 14.4, unilateral facial palsy 10% vs 25.9% and albuminocytologic dissociation 41.3% vs. 71.7%.Multivariate analysis found AMAN as an independent predictor of an unfavorable outcome OR: 3.34 (p = 0.03) CONCLUSIONS: AMAN subtype is the most frequent presentation of GBS in Mexican adult patients and an independent predictor of inability to walk independently at 3 months after discharge.

Comparison between high-performance liquid chromatography and gas chromatography methods for fatty acid identification and quantification in potato crisps

A reversed-phase high performance liquid chromatographic (RP-HLPC) method was compared with a gas chromatography-flame ionization detection (GC-FID) method for determining fatty acids in potato crisps. Different extraction procedures were used. Fatty acids were quantified by linear regression. Both methods presented good precision (R.S.D. < or = 5.88%) and recovery (> or = 82.31%). The precision using HPLC method was slightly better than for GC-FID method. There was good agreement between the fatty acid composition of potato crisps analysed by both methods. For most purposes the HPLC method would be better. However, when more fatty acids need to be analysed, GC is a more suitable method.

Prognostic Factors in Elderly Patients With Guillain-Barré Syndrome: Does Age Matter?

Introduction

Twenty to 40% of Guillain Barré syndrome (GBS) patients will not be able to walk independently despite effective treatment. Older patients carry additional risks for worse outcomes.

Methods

A single center, ambispective cohort study was performed. Only subjects ≥18 years with a 3-month follow-up were included. Elderly patients were considered as a whole if ≥ 60 years. Demographics, CSF and nerve conduction studies were compared. A binomial logistic regression and Kaplan-Meier analyses were carried out to estimate good prognosis (Hugues ≤2) at 3-month follow-up.

Results

From 130 patients recruited, 27.6% were elderly adults. They had a more severe disease, higher mEGOS and more cranial nerve involvement. Age ≥70 years, invasive mechanical ventilation and axonal subtype, portrayed an unfavorable 3-month outcome. Further analysis demonstrated an earlier recovery in independent walk at 3 months for patients <70 years.

Conclusions

Elderly patients with GBS have a more severe disease at admission and encounter worse prognosis at 3-month follow-up, especially those above 70 years.

Pharyngeal-Cervical-Brachial Variant of Guillain-Barré Syndrome

Guillain-Barré syndrome (GBS) represents the main cause of flaccid paralysis worldwide. Although most cases have a typical clinical presentation of symmetric ascending flaccid paralysis with areflexia or hyporeflexia, this disease may present as multiple clinical entities, therefore representing a diagnostic challenge for physicians, who should consider these variants when assessing neuropathies. The pharyngeal-cervical-brachial (PCB) variant of Guillain-Barré syndrome is defined by rapidly progressive oropharyngeal and cervicobrachial weakness associated with hyporeflexia or areflexia in the upper limbs. It is present in 3% of all Guillain-Barré syndrome cases and is characterized by axonal rather than demyelinating neuropathy. 

We present a pharyngeal-cervical-brachial variant case in a 55-year-old male who presented to the neurological emergency department with a three-day history of progressive and continuous dysarthria, dysphagia to solids, and tongue numbness, later developing paresthesia and weakness in the upper limbs. On physical examination, slight bilateral facial weakness, limited soft palate elevation, absent gag reflex, and limited tongue lateralization were found. Additionally, weakness was found bilaterally in the upper limbs and the flexor and extensor muscles of the neck with preserved muscle strength in the lower limbs. The patient presented upper limb hyporeflexia with lower limb hyperreflexia. A lumbar puncture was performed, revealing protein levels of 35 mg/dL and no cells in the cerebrospinal fluid. Nerve conduction studies reported acute motor and sensory axonal neuropathy (AMSAN). Management of the patient consisted of IgG administration and nasogastric tube insertion.

Dysautonomia and related outcomes in Guillain-Barre syndrome

BACKGROUND

Guillain-Barre syndrome (GBS) presents an annual incidence of 1.2-2.3 per 100,000. Sympathetic and parasympathetic nervous systems' peripheral control of visceral organs is affected by GBS aberrant immune response. Associated cardiovascular, gastrointestinal, sudomotor, pupillary, and other systems disturbances cause significant morbidity and mortality. This study aims to evaluate the dysautonomia spectrum in GBS patients, its relationship with patient outcomes, and compare it with those without autonomic disturbances.

METHODS

We performed an ambispective review study of patients with GBS and dysautonomia admitted to the Institute of Neurology from 2017 to 2021. We recorded demographics, comorbidities, nerve conduction studies, clinical course, hospital complications, and functional outcomes.

RESULTS

We included 214 patients, mean age 46.44 ± 16.49 years, 51 (31 %) presented dysautonomia, hypertension in most of the patients 39 (84.8 %), hypotension 35 (76.1 %), tachycardia 35 (76.1 %), enteric dysmotility 35 (76.1 %), and need for vasopressor 27 (58.7 %) were common characteristics. Twenty (39.2 %) with a demyelinating form and twenty (39.2 %) with an axonal motor form. The bivariate analysis report factors associated with dysautonomia, were lower cranial nerves (VII, IX, X) involvement (p = 0.002), need for mechanical ventilation (p = 0.0001) and intensive care (p = 0.0001), higher mEGOS (p = 0.05), EGRIS (p = 0.004), GBS disability score (p = 0.004), and delirium presence (p = 0.001). Kaplan-Meier survival analysis showed that dysautonomic patients needed more days for the independent walk (p = 0.004). There was no associated mortality.

CONCLUSIONS

Autonomic dysfunction in GBS significantly affects the peripheral nervous system. With consequently worse functional results. Further investigation needs to clarify whether more aggressive treatment is beneficial in this category of GBS.

Vacuolar Myopathy Associated to CACNA1S Mutation as a Rare Cause of Late-Onset Limb-Girdle Myopathy: A Case Report

Late-onset limb-girdle myopathies pose a diagnostic challenge. The most common etiologies are inflammatory, followed by genetic and metabolic. Rare cases include limb-girdle dystrophies and permanent myopathies (vacuolar), such as those associated with hypokalemic periodic paralysis (HypoPP). We present the case of a 59-year-old male who initiated with episodic acute severe weakness when he was 11, during which serum potassium levels of <2.5 meq/L were revealed during workup. Potassium reposition reversed these episodes. They occurred every three to five years, and the last episode was five years prior to the current illness. When he was 58, he presented progressive pelvic girdle weakness. On examination, he presented decreased strength in the iliopsoas and quadriceps. The laboratory results showed mildly elevated creatine kinase. Muscle biopsy revealed a vacuolar myopathy, and genetic testing identified a pathogenic variant in the CACNA1S gene, locus 1q32.1 [c.3716G> A (p.Arg1239His), heterozygous state].

Simultaneous determination of thiamin and riboflavin in the sea urchin,Paracentrotus lividus, by high-performance liquid chromatography

Thiamin and riboflavin were determined in the sea urchin, Paracentrotus lividus, by reversed-phase liquid chromatography with fluorescence detection and a mobile phase consisting of 72% 0.005 M NH(4)OAc and 28% MeOH at a flow rate of 1.450 ml/min. The total analysis time never exceeded 20 min. After acid hydrolysis and enzymatic digestion, thiamin was oxidized to thiochrome and the oxidized fraction was purified and concentrated by solid-phase extraction. Limits of detection were 9 pg/ml and 80 pg/ml for thiamin and riboflavin, respectively. Good results were obtained with respect to repeatability (RSD%<2.4) and recovery (>91.3%).

Guillain-Barre syndrome during COVID-19 pandemic: experience from a referral healthcare center in Mexico

INTRODUCTION

To describe clinical characteristics and electrophysiological variants of GBS cases during the pandemic, we carried out a comparative analysis between SARS-CoV2 related GBS and non-SARS-CoV2 patients and then compared to the 2019 cases.

PATIENTS AND METHODS

We carried out a cross-sectional study of GBS patients diagnosed according to Asbury and Cornblath criteria. We collected information on clinical and paraclinical variables. We defined a SARS-CoV-2 related GBS case according to the description of Ellul et al. We used Hadden criteria to classify the electrophysiological variants. We performed a comparative analysis between groups.

RESULTS

Fourty-two patients were diagnosed with GBS in 2020, men 64.2%, age 46 ± 17.4 years, patients with obesity/overweight 42.8%, previous diarrhea 31%, history of respiratory tract infection 14.2%. Guillain Barre Disability Scale = 3 points 71.4% and, cranial nerve involvement 69%. The most frequent electrophysiological variant was acute inflammatory demyelinating polyradiculoneuropathy (AIDP) 53.5%. Seven (16.6%) cases were SARS-CoV2 related, four men, age 43.4 ± 13.4 years. When comparing patients with GBS in 2020 vs patients in 2019, we observed a decrease in the previous infection history during 2020 (45.2% vs 73.3%, p-value = 0.005) and a decrease in previous respiratory infection (14.2% vs 33.3%, p = 0.045), as well as a higher frequency of cranial nerve involvement, and albuminocytologic dissociation.

CONCLUSIONS

SARS-CoV2 virus infection preventive measures may be impacting the presentation of post-infectious diseases such as GBS. We did not observe an increase in GBS cases during 2020. Also, the AIDP variant were more frequent in our population in the COVID-19 pandemic.

Instability of an aromatic amine in fatty food and fatty food simulant: characterisation of reaction products and prediction of their toxicity

It is a well-known fact that amines are not stable in food of a fatty nature. In this study the synthesis and characterisation of the products obtained as a result of the reaction of amines in a fatty medium are reported. Based on the well-known reactions among amines and acid and esters groups, two novel compounds were synthesised using m-xylylenediamine (mXDA), a primary diamine widely used as monomer in the manufacture of food contact materials and two fatty acids, oleic acid and palmitic acid, which occur in most fats. The resulting compounds were two molecules belonging to the family of fatty acid amides, dioleamide and dipalmitamide. A complete characterisation of both products was carried out employing several techniques such as infrared spectroscopy, (1)H- and (13)C-NMR spectroscopy, electron ionisation mass spectrometry, LC-MS/MS and UV spectrometry. The results obtained by the different techniques were well correlated. In the second part of the work, the formation of these compounds in real samples was evaluated. For this purpose a certain volume of olive oil was spiked with a known amount of mXDA. Olive oil was selected as a fatty medium since it is a widely consumed food and additionally is used as a fatty food simulant in migration studies of food contact materials. A method was developed to extract the fatty acid amides from the fatty matrix, which were then identified by LC-MS/MS. The toxicity of the synthesised compounds was predicted using a toxicity estimation software tool.

[Autoinmune psychosis]

With the advent of the description of autoimmune encephalitis by different neuronal cell-surface antibodies (anti-NMDAr, among others) and that psychosis may be the only manifestation without neurological symptoms (epilepsy, movement disorders, autonomic dysfunction, altered state of consciousness) in 6.5 % of patients, the term "autoimmune psychosis" has become remarkably interesting among researchers. In 2020, an international consensus for the description and diagnostic approach of autoimmune psychosis was created. Through this consensus, by taking different criteria into account, the definition of autoimmune psychosis was proposed at different degrees of certainty (possible, probable, and defined). The purpose of these criteria is to underpin the autoimmune origin in patients who present psychosis with atypical characteristics, thus justifying the realization of laboratory studies and complementary clinical tests (lumbar puncture, electroencephalogram, and magnetic resonance imaging of the brain); in addition, these criteria are applied in patients with psychosis without neurological symptoms that do not fully meet the criteria of autoimmune encephalitis. As in autoimmune encephalitis, the early initiation of immunotherapy has a direct impact on the functional prognosis of patients, so an early initiation of treatment must be considered in clinical scenarios of probable or definite autoimmune psychosis.

Guillain-Barre syndrome in Mexico: clinical features and validation of Brighton Collaboration Group criteria

INTRODUCTION

As SARS-CoV-2 vaccination is ongoing in Mexico and Guillain-Barre syndrome (GBS) cases have been reported, validation of Brighton criteria in Mexico is necessary. Moreover, epidemiology of GBS in Mexico differs from European and North American countries.

OBJECTIVE

To describe the clinical, cerebrospinal and electrodiagnostic features in Mexican patients diagnosed with GBS and classify them according to the Brighton Collaboration Group diagnostic criteria. Patrients and methods. An ambispective cohort study was conducted. We included patients that fulfilled the National Institute of Neurological Disorders and Stroke (NINDS) diagnostic criteria for Guillain-Barre syndrome. Patients in this study were classified according to Brighton collaboration group levels of certainty for Guillain-Barre syndrome.

RESULTS

Sixty eight percent of patients were male. Of the 248 patients included, 58.4% had history of a precedent infection, mean time from symptom onset to admission was 5 (1-30) days. Mean Medical Research Council sum score 30.3 ± 15.5. Almost 98% of patients had a monophasic course. Level 1 of certainty according to Brighton collaboration group criteria was fulfilled by 54.6% of patients, level 2 by 45% and level 4 by 0.6%. Patients meeting level 2 of certainty were mostly because normal cerebrospinal fluid findings or findings in nerve conduction studies not consistent with any GBS variants.

CONCLUSION

GBS is a frequent autoimmune neuropathy that has been associated with preceding infections and with vaccination campaigns. For SARS-CoV-2 vaccination campaign in Mexico, validation of Brighton Criteria is necessary. Although Mexico's GBS epidemiology has been changing throughout recent years, this study provides similar data compared to other countries.

[Vulpian-Bernhardt syndrome. Its frequency and clinical and electrophysiological features in a tertiary care centre in Mexico]

INTRODUCTION

Vulpian-Bernhardt syndrome (VBS) is an atypical rare clinical phenotype of amyotrophic lateral sclerosis (ALS) that causes a significant delay in diagnosis, and thus it is important to recognise its clinical and electrophysiological features.

MATERIALS AND METHODS

Retrospective cross-sectional study. We reviewed the clinical records of patients diagnosed with ALS in the period from January to December 2019. Those meeting criteria for VBS were included so as to describe their frequency as well as their clinical and electrophysiological features.

RESULTS

Twenty patients (15.8%) met criteria for VBS; 55% were female; age at onset of symptoms was 46.6 ± 12.9 years; 40% were smokers; median delay in diagnosis was 24 (12-96) months; median time to involvement of the second body segment was 24 (12-132) months, which was lumbosacral in 65%; mean Revised Amyotrophic Lateral Sclerosis Functional Rating Scale score was 27 ± 7 points; 45% met the El Escorial criteria for ALS defined at diagnosis and 58.8% met the Awaji criteria. There were 19 nerve conduction studies and 17 electromyograms, and an abductor digiti minimi-abductor pollicis brevis (ADM/APB) ratio < 0.6 was found in 63% (split hand).

CONCLUSIONS

There is a significant delay in the diagnosis of motor neuron diseases in general and more particularly in VBS. Calculating the ADM/APB ratio and applying the Awaji criteria in the electrophysiology study can be a valuable aid to increase diagnostic certainty in this clinical entity.

[Prevalence of vitamin D insufficiency and deficiency in Mexican adults with allergic asthma]

BACKGROUND

Hypovitaminosis D has been associated with various chronic diseases such as infections, autoimmune diseases, chronic obstructive pulmonary disease, cancer and asthma Objective: The objective at hand is to determine the prevalence of vitamin D (VD) insufficiency and deficiency in adults with allergic asthma.

OBJECTIVE

Objective: The objective at hand is to determine the prevalence of vitamin D (VD) insufficiency and deficiency in adults with allergic asthma.

METHODS

Through a cross-sectional study, we analyzed corresponding data amongst 135 patients. VD concentration was categorized as sufficient (≥ 30 ng/mL), insufficient (21-29 ng/mL), and deficient (≤ 20 ng/mL). The level of VD deficiency was measured through chemo-luminescence. We estimated the prevalence of VD alterations and their respective confidence intervals at 95 % (CI 95 %).

RESULTS

Within the analyzed population, there were 99/135 women (73.3 %); the mean age was 34.5 ± 10.3 years. The mean concentration of VD was 17.9 ± 6.9 ng/mL and the median was 17 ng/mL. The prevalence of VD insufficiency and deficiency was 25.2 % (CI 95 %, 18.6-33.2 %) and 71.1 % (CI 95 %, 62.9-78.1 %), respectively; VD concentrations ≤ 10 ng/mL had 13.3 % (CI 95 %, 8.5-20.2 %) and ≥ 30 ng/mL at 3.7 % (CI 95 %: 1.4-8.6 %). When we contrasted the men to the women, the median concentration of VD did not differ significantly (16 ng/mL vs. 18 ng/mL, p = 0.71).

CONCLUSION

In this study, patients with allergic asthma had distinctively reduced VD concentration levels; future research will determine if and how VD affects the severity of asthma.

Prognostic Implications of Early Albuminocytological Dissociation in Guillain-Barré Syndrome

BACKGROUND

Half of Guillain-Barré syndrome (GBS) present elevated cerebrospinal fluid (CSF) protein levels within 1 week since symptom onset and 80% within 2 weeks. Our objective was to determine the clinical and prognostic implication of albuminocytological dissociation in early GBS.

METHODS

An ambispective cohort study was conducted. Good outcome was considered if the patient was able to walk unaided (Guillain-Barré disability score [GDS] ≤ 2 points) at 3-month follow-up. Patients were classified into two groups: with and without albuminocytological dissociation; we compared clinical and paraclinic characteristics between the groups. We analyzed clinical and electrophysiological factors related to presenting early dissociation through a multivariate model.

RESULTS

We included 240 patients who fulfilled Asbury criteria for GBS. On further selection, only 94 patients fulfilled inclusion. Mean age was 45.94 ± 17.1 years and 67% were male. Median time from symptom onset to admission was 5 days (IQR 3-6). Regarding albuminocytological dissociation and electrophysiological variants, we found a significant difference: acute inflammatory demyelinating polyneuropathy (AIDP) [60.6% vs 26.2%, p = 0.002], acute motor axonal neuropathy (AMAN) [21.2% vs 49.1%, p = 0.009] and acute motor sensory axonal neuropathy (AMSAN) [12.1% vs 1.6%, p = 0.05]. We did not observe significant differences in recovery of independent walking in short term between both groups. The presence of conduction block in any variant (OR 3.21, 95% CI 1.12-9.16, p = 0.02) and absence of sural registration (OR 5.69, 95% CI 1.48-21.83, p = 0.011) were independent factors related to early dissociation.

CONCLUSIONS

Early dissociation (<7 days) is not associated with any particular clinical feature or unfavorable outcome. It is more common to see in AIDP rather than axonal variants.

Efficacy of long-term prednisone therapy in patients with chronic inflammatory demyelinating polyneuropathy (CIDP): a retrospective cohort study

INTRODUCTION

Patients with CIDP respond adequately to steroid therapy and intravenous immunoglobulin (IVIG). However, few patients have access to IVIG in developing countries. Little information exists about the clinical response to steroid therapy in Latin American countries.

OBJECTIVE

to describe the long-term functional clinical response (24 months) to prednisone therapy in CIDP patients.

MATERIAL AND METHODS

A retrospective cohort was conducted. Selection included patients with definitive CIDP diagnosis according to European criteria from the Neuromuscular Diseases clinic of the National Institute of Neurology and Neurosurgery between January 2016 and December 2020. Good response to steroid therapy was defined as with improvement in at least one point on the GBS disability score. Poor response to steroid therapy was defined as patients who did not show improvement in at least one point on the GBS disability score. Patients were evaluated at 3, 6, 12, 18 and 24 months.

RESULTS

Forty-seven patients with CIDP were included. Half of them were male and mean age was 46±15 years. Mean time since symptom onset to diagnosis was 6 (IQR 2-12) months. The most common clinical variant was sensory-motor 57.4%, followed by acute-onset CIDP 21.3% and atypical variants 21.2%. At diagnosis our patients presented: mean GBS disability score of 3 (2.25-4) points, MRC score 39.5 ± 12 points, independent gait in 17%, mean prednisone dose of 50 mg (32.5-50). Twenty-four months after prednisone therapy, a less mean GBS disability score -1(0-2) points-, mean MRC score 56.3 ± 5.1 points, independent gait 93% and prednisone dose 1 (0-5) mg. Patients with poor three-month functional clinical response had a delay in diagnosis > 6 months (64.7% vs 27.5%) and atypical clinical variants (47% vs 6.8%).

CONCLUSION

CIDP patients treated with prednisone have good long-term functional clinical response. Delay in diagnosis and atypical variant are common clinical characteristics for poor functional clinical response in treatment with prednisone.

High-performance liquid chromatographic determination of glycogen in sea urchin gonads with refractive index detection

A high-performance liquid chromatographic method using refractive index detection for the determination of glycogen in sea urchin (Paracentrotus lividus) gonads is developed. After alkaline digestion with sodium carbonate, samples are adjusted to pH 4.6 with citric acid and incubated with amyloglucosidase to hydrolyze the glycogen. The resulting glucose is determined using a Spherisorb NH2 column as the stationary phase and an acetonitrile-water mixture (80:20, v/v) as the mobile phase. The relative standard deviation (%) was 3.57, the limit of detection was 40.1 microg/mL, and the recovery percentage was 97.2%.