Estudio evolutivo de metabolitos porfirínicos de un caso de porfiria cutánea tardía / Porphyrins in a case of porphyria cutanea tarda: follow-up study

Resumen Las porfirias son errores congénitos poco frecuentes del metabolismo de las porfirinas. La porfiria cutánea tardía (PCT) es la más frecuente dentro de este grupo de enfermedades. Reportamos el estudio evolutivo de metabolitos porfirínicos de una paciente de 51 años con porfiria cutánea tardía, cuatro años después de su diagnóstico. Durante este período, se le indicó un esquema terapéutico de flebotomías en el Instituto de Hematología e Inmunología. Uno de los exámenes complementarios para su seguimiento fue la determinación de porfirinas totales en la orina, plasma y heces. Los resultados del estudio bioquímico de las porfirinas mostraron mejoría en todos los parámetros, lo que contribuyó a corroborar la utilidad del estudio de estos metabolitos como seguimiento de esta enfermedad y efectividad del tratamiento.

Abstract Porphyrias are rare congenital errors in the metabolism of porphyrins. Porphyria cutanea tarda is the most frequent among different types of porphyrias. We report the follow-up study of porphyrin metabolites of a 51-year-old patient with porphyria cutanea tarda four years later of her diagnosis. During this period, it was indicated a therapeutic scheme of phlebotomies in the Institute of Hematology and Immunology. One of the complementary examinations for its follow-up was the determination of total porphyrins in the urine, plasma and feces. Porphyrins in plasma decreased from 13 500 nmol/L at onset of disease to 250 nmol/L four years later. Although, porphyrins in feces and plasma could not quantify, we observed non-presence of peaks at 405 nm and 615.1 nm, respectively. These results contributed to corroborate the usefulness of the study of these metabolites for monitoring of this disease and effectiveness of the treatment.

Serum neuron-specific enolase and S100 calcium binding protein B biomarker levels do not improve diagnosis of acute stroke.

BACKGROUND: The high sensitivities and specificities reported for blood biomarkers as a supportive test in the diagnosis of acute stroke do not correspond with their performance for decision-making in emergency situations. METHODS: Seventy-two patients with suspected stroke were recruited: 44 with ischaemic stroke, 17 with haemorrhagic stroke and 11 stroke mimics, as well as a high-risk control group of 79 individuals. Serum neuron-specific enolase (NSE) and S100 calcium binding protein B (S100B) biomarker levels were determined on admission, using immunoassay kits. The sensitivities and specificities of NSE and S100B for distinguishing acute stroke from stroke mimics and high-risk controls were calculated. RESULTS: For cut-off values (NSE ≤ 14 micrograms per litre and S100B ≤130 nanograms per litre) the sensitivity was 53% and 55% respectively. Specificity was 64 for both versus the stroke mimic group. Specificity was higher (79% and 86% respectively) when calculated on the basis of the control group. CONCLUSIONS: This study supports the evidence indicating that serum levels of NSE and S100B do not improve the diagnosis of acute stroke.

High proportion of mannosidosis and fucosidosis among lysosomal storage diseases in Cuba.

Although lysosomal storage disorders (LSDs) are considered individually rare, as a group they present a non-negligible frequency. Few studies have been made of populational occurrence of LSDs; they have been conducted predominantly on Caucasian populations. We studied the occurrence of LSDs in Cuba. Data from individuals who had been referred to the Institute of Neurology and Neurosurgery in Havana from hospitals all over the country between January 1990 and December 2005 were analyzed. This institute was the only laboratory to provide enzyme-based diagnostic testing for 19 LSDs in Cuba during this period. Occurrence rates were calculated by dividing the number of postnatal diagnoses by the number of births during the study period. The combined occurrence of LSDs in Cuba was 5.6 per 100,000, lower than that reported in other studies conducted on Caucasian populations. The most frequent individual LSDs were: mucopolysaccharidosis type I (1.01 per 100,000) and, surprisingly, alpha-mannosidosis (0.72 per 100,000) and fucosidosis (0.62 per 100,000). These findings may be related to specific genetic characteristics and admixture of the Cuban population. This is the first comprehensive study of the occurrence of LSDs in Cuba. We conclude that the epidemiology of these diseases can vary regionally, and we stress the need for similar surveys in other Latin American countries.

[Mucopolysaccharidosis: 20-year enzymatic diagnosis in Cuba]. / Mucopolisacaridosis: diagnostico enzimatico de 20 anos en Cuba.

INTRODUCTION: Mucopolysaccharidoses (MPS), which belong to the family of inborn errors of metabolism, are characterised by their severe clinical manifestations (skeletal, neurological and visceral) and a chronic, progressive course leading to death at early stages of life. AIM. To accomplish an enzymatic diagnosis and characterise MPS within the Cuban population. SUBJECTS AND METHODS: A total of 664 patients with a clinical suspicion of some type of MPS were referred to the Institute of Neurology and Neurosurgery in Havana in order to determine a possible enzymatic deficiency and to classify the type of MPS involved in each case. Enzymatic determinations of alpha-L-iduronidasa, alpha-N-acetylglucosaminidase, beta-galactosidase, arylsulphatase B and beta-glucuronidase were performed in leukocyte homogenate for MPS I, IIIB, IVB, VI and VII, respectively, in patients, parents and controls. RESULTS. In all, 42 cases of MPS were diagnosed: MPS I (62%, n = 26), MPS VI (29%, n = 12), MPS IIIB (7%, n = 3) and MPS IVB (2%, n = 1). No patients with MPS VII were identified. The patients diagnosed with MPS were of both sexes and ages ranged between 4 months and 10 years. The specific activity of the enzymes that were studied was deficient in patients with respect to parents and controls. The percentage of activity was lower in patients compared to parents. CONCLUSIONS: These studies made it possible to evaluate the enzymatic deficiencies and to establish the diagnosis of MPS I, MPS IIIB, MPS IVB, MPS VI and MPS VII in the Cuban population.

An appraisal of blood-cerebrospinal fluid barrier dysfunction during the course of Guillain Barré syndrome.

BACKGROUND: Elevated cerebrospinal fluid (CSF) total protein (TP) concentration (mainly due to a dysfunctional blood-CSF barrier (B-CSFB)) with normal cell count is a hallmark for the diagnosis of Guillain-Barriota syndrome (GBS). AIMS: This work presents the evaluation of B-CSFB dysfunction with respect to the course, severity, and clinical features of GBS. MATERIALS AND METHODS: A sample of CSF was collected on admission from 68 patients of both genders (15 children and 53 adults) diagnosed with GBS. A follow-up CSF sample was obtained approximately 15 days after admission. TP concentration was determined in the CSF and 7.5% polycrylamide gel electrophoresis was employed for serum and CSF protein fractioning. A low percentage of prealbumin fraction was considered a test of impaired B-CSFB. RESULTS: Elevated TP concentration and lower prealbumin were observed in almost 70% of the patients on admission, but this percentage was lower (52.4%) during the first week from onset of symptoms. Both variables were directly associated with the time of evolution of the disease and also with a greater clinical severity. Follow-up CSF studies showed higher CSF TP and lower prealbumin percentages, while deceased patients did not display this response pattern in the follow-up CSF. CONCLUSIONS: B-CSFB dysfunction was present in only half of the patients with GBS during the first week from onset and it was directly associated with progression and clinical severity; nevertheless, a low B-CSFB dysfunction response during follow-up was associated with a lethal outcome, suggesting it could also serve a 'protective' effect during regeneration.

Neuromyelitis optica positive antibodies confer a worse course in relapsing-neuromyelitis optica in Cuba and French West Indies.

BACKGROUND: In Caucasian populations neuromyelitis optica (NMO-IgG) antibody has been detected in 27.1% / 78.2% of patients with relapsing-NMO (R-NMO). The prevalence reported for the disease in the Caribbean is 3.1/100,000 in the French West Indies (FWI) and 0.52 /100,000 in Cuba, but the NMO antibody status is unknown. OBJECTIVE: To assess the NMO-IgG antibody status of Cuban/FWI RNMO patients, comparing with European cases tested at the same laboratories. METHODS: Serum NMO-IgG antibodies were assayed in 48 R-NMO patients (Wingerchucks 1999 criteria): Cuba (24)/FWI (24), employing Lennon et als method. We compared the demographic, clinical, disability and laboratory data between NMO-IgG +/- patients. All the data were reviewed and collected blinded to the NMO-IgG status. RESULTS: Seropositivity of the NMO-IgG antibody demonstrated a lower rate in the Caribbean (33.3%), as compared with Caucasian patients from Spain/Italy (62.5%) and France (53.8%). Caribbean patients with NMO-IgG (+) displayed more attacks, more spinal attacks and a higher EDSS than NMO-IgG (-) cases, while brain and spinal cord MRI lesions were more frequent during remission, with more vertebral segments, more gray, white matter and holocord involvement. CONCLUSIONS: NMO IgG positive antibodies in NMO patients had a lower rate in the Caribbean area - where the population has a predominant African ancestry - than in Caucasian Europeans, suggesting the influence of a possible ethnic factor in the pathogenesis of the disease, but they confer a worse course with more attacks, more disability and MRI lesions.

[Descriptive epidemiology of neuromyelitis optica in the Caribbean basin]. / Epidémiologie descriptive de la neuromyélite optique dans le bassin caraïbéen.

INTRODUCTION: Data on epidemiology of neuromyelitis optica (NMO) remained scarce in the last century, but the recent development of diagnostic criteria now enables inclusion of both monophasic and relapsing NMO in epidemiologic studies. Given the rarity of NMO, multicentric studies are needed to confirm a presumed higher frequency in women and in populations of black/Asian ancestry. The Caribbean basin is a suitable area for collecting a large NMO cohort and to assess the prevalence, incidence, and mortality of this disorder. PATIENTS AND METHODS: This population-based survey of the NMO spectrum in the French West Indies (FWI) and Cuba included 151 cases. RESULTS: Ninety-eight patients (female/male ratio: 9.8) had NMO. Age of onset in NMO patients was 30.9 years. Mean annual incidence of NMO in the French West Indies for the period July 2002 to June 2007 was 0.20/100,000 inhabitants (IC 95% 0.05-0.35). Incidence rates were steady in the FWI during the 1992 to 2007 period. Decreasing mortality in the FWI during the 1992 to 2007 period explained the increasing prevalence which was 4.20/100,000 inhabitants (IC 95% 3.7-5.7) in June 2007. The prevalence of NMO in Cuba on November302004 was 0.52/100,000 inhabitants. (IC 95% 0.39-0.67). Prevalence rates did not differ significantly by ethnic group in Cuba, however, black Cubans exhibited the highest prevalence. DISCUSSION: Epidemiologic studies on NMO in each population are needed to determine whether aggressive therapies can reduce the mortality of this devastating disorder. CONCLUSION: In the Caribbean basin, NMO involves almost exclusively young women; the epidemiologic data confirm its predilection for populations of African ancestry. In the FWI, recent and aggressive therapy has lowered mortality but with an increase in the prevalence of NMO.

Mucopolisacaridosis: diagnóstico enzimático de 20 años en Cuba / Mucopolysaccharidosis: 20-year enzymatic diagnosis in Cuba

Las mucopolisacaridosis (MPS), dentro de los errores innatos del metabolismo, se caracterizan por sus manifestaciones clínicas graves (esqueléticas, neurológicas y viscerales), con un curso crónico y progresivo, que conducen a la muerte en etapas tempranas de la vida. Objetivo. Diagnosticar enzimáticamente y caracterizar las MPS en la población cubana. Sujetos y métodos. Se remitió un total de 664 pacientes con sospecha clínica de algún tipo de MPS al Instituto de Neurología y Neurocirugía de La Habana para determinar la posible deficiencia enzimática y clasificar el tipo de MPS. Las determinaciones enzimáticas de alfa-L-iduronidasa, N-alfa-acetilglucosaminidasa, beta-galactosidasa, arilsulfatasa B y beta-glucuronidasa se realizaron en homogenado de leucocitos para MPS I, IIIB, IVB, VI y VII, respectivamente, en pacientes, padres y controles...(AU)

Neuromyelitis optica and multiple sclerosis in sisters.

INTRODUCTION: The association of neuromyelitis optica (NMO) and multiple sclerosis (MS) has been reported, but details of the cases were not described. We report two Venezuelan Caucasian sisters with human leukocyte antigen (HLA) typing. RESULTS: Patient 1 fulfilled McDonald, et al. criteria with HLA A*24; B*07,*15; DRB1*01,*16 (DR2 positive). Patient 2 fulfilled the NMO revised criteria of Wingerchuck, et al. with HLA A*02,*24; B*07,*40; DRB1*04,*08, similar to Canadian aboriginal NMO cases and the Yukpa population from Venezuela. CONCLUSION: These cases confirmed the coexistence of NMO and MS in sisters, and further studies are needed to understand the genetic linkage between these diseases.

Brain magnetic resonance imaging findings in acute relapses of neuromyelitis optica spectrum disorders.

We studied cranial magnetic resonance imaging (MRI) lesions in three women with acute attacks of recurrent longitudinally extensive transverse myelitis (r-LETM), recurrent-optic neuritis (r-ON) and r-LETM-CNS. Neuromyelitis Optica -immunoglobulin (IgG) antibody was positive in all cases. Brain MRI (1.5 Tesla) was performed according to protocol from consortium MS centre. We described the cranial lesions in brain MRI of acute relapses. These lesions were different from MS, most had an asymptomatic course which disappeared with time, protocol from consortium of MS centre criteria for brain MRI and seropositivity of NMO-IgG are useful tools for differentiate acute lesions of NMO/MS.

Brain magnetic resonance imaging findings in relapsing neuromyelitis optica.

BACKGROUND: Some studies showed abnormalities in brain magnetic resonance imaging (MRI) of relapsing neuromyelitis optica (R-NMO) from 12 to 46%. These abnormalities are described as compatible/non-compatible with multiple sclerosis (MS). OBJECTIVE: To describe the abnormal brain MRI lesions in R-NMO with imaging studies conducted with more sensitive white matter change techniques. METHODS: Thirty patients with R-NMO were selected. All MRI brain studies were performed with a 1.5-T Siemens MRI system according to the Standardized MR Imaging Protocol for Multiple Sclerosis from the Consortium of MS Centers Consensus Guidelines. RESULTS: Brain MRI images were evaluated in 29 R-NMO cases because in one case the MRI images were not appropriate for the study. Of these 29 brain MRI studies, 19 cases (65.5%) had at least one or more lesions (1-57) and 10 were negative (34.4%). Brain MRI findings in 19 cases were characterized in T2/fluid-attenuated inversion-recovery (FLAIR) by the presence of subcortical/deep white matter lesions in 16 (84.2%) cases (1-50), most of them <3 mm and without juxtacortical localization. Periventricular lesions were observed in 13 (68.4%) cases, but morphologically they were not oval, ovoid or perpendicularly orientated. Infratentorial lesions, all >3 mm, were observed in 4 (21.05%) cases without cerebellar involvement. T1 studies demonstrated absence of hypointense regions. Optic nerve enhancement was observed in 6/19 patients (31.5%). None of the brain MRI abnormalities observed were compatible with Barkhof et al. criteria of MS. CONCLUSIONS: This study, based on a Cuban patient population, with long duration of disease, good sample size and detailed characterization by MRI, demonstrated the brain MRI pattern of R-NMO patients, which is different from MS.

Down's syndrome and neuromyelitis optica (Devic's disease). An autopsy-proven case.

Neuromyelitis optica (NMO) has been attributed to different underlying pathological events. The aim of this paper is to present the first case report of a patient with Down's syndrome (DS) who died of a fulminant NMO. A 29-year-old woman with DS developed acute transverse myelitis, with complete visual loss and swollen optic discs. Two days later, she developed quadriplegia, respiratory arrest and died. The anatomical study demonstrated typical findings of DS in the brain without demyelinating lesions. A severe destruction of medulla and cervical cord with a very high degree of demyelination of the optic nerves was typical of monophasic NMO (Devic's disease). Most of the cases of NMO in Cuba are of the relapsing form, but this case report is the first one with monophasic NMO and DS with a very aggressive course. The link of the pathogenetic relationship between DS and NMO remains unclear; it may well be coincidence but the fact that the patient died very shortly after the onset suggests, at least on clinical grounds, that the presence of DS could have accelerated the fatal evolution of NMO.

[Mucopolysaccharidosis type I in the Cuban population]. / Mucopolisacaridosis tipo I en la población cubana.

INTRODUCTION: Of all the innate errors of the metabolism, the mucopolysaccharidoses (MPS), a kind of lysosomal disease, are especially significant because of the serious clinical features they give rise to and the therapeutic difficulties they entail. Diagnosis of the index case is essential so that families can gain access to the preventive benefits of genetic counselling. To date, seven types of MPS and 11 enzyme deficiencies have been described. AIMS: Patients with a clinical diagnosis that leads the clinician to suspect they may be suffering from some type of MPS are referred to the Institute of Neurology and Neurosurgery to determine the possible enzyme deficiencies that will provide us with the key to a successful diagnosis. PATIENTS AND METHODS: A total of 588 patients who were clinically suspected of suffering from MPS, in whom 1,502 enzyme analyses were performed in order to classify the type of MPS they were suffering from. The MPS under examination are MPS I, MPS IIIB, MPS IVB, MPS VI and MPS VII. RESULTS: MPS I, or alpha-L-iduronidase deficiency, is the most commonly found with 23 cases (4.08% of the patients studied); 13 were females and the other 10 were males. Of the 23 cases, 10 presented the severe Hurler phenotype with mental retardation, five had the Scheie phenotype with preserved intelligence and eight displayed the intermediate Hurler-Scheie phenotype. Diagnosis was reached before the end of the first year in eight patients, between 1 and 5 years in nine of them and between 6 and 10 years in two cases. Enzyme activity in leucocytes was significantly lower in patients as compared to a control group and with respect to the parents (heterozygotes), and even comparing these to the control group, with a slight and expected overlap. CONCLUSION: The biochemical methodology used allows us, then, to reach a sure biochemical diagnosis and to offer the families the benefits of genetic counselling.

Effects of taurine deficiency and chronic methanol administration on rat retina, optic nerve and brain amino acids and monoamines.

A chronic methanol (MeOH) intoxication scheme (2 g/kg/day ip for 2 weeks) was carried out in Sprague-Dawley rats, previously depleted of folates with methotrexate (MTX). beta-Alanine (beta-Ala), 5%, was also administered to some animals in the drinking water. Amino acids were determined in plasma, retina, optic nerve, hippocampus and posterior cortex by HPLC with fluorescence detection and monoamines in retina, hippocampus and posterior cortex by electrochemical detection. Beta-Ala administration reduced taurine (Tau) levels in plasma, hippocampus and posterior cortex, but not in retina and optic nerve. Aspartate (Asp) concentration in the optic nerve was increased in MTX-MeOH treated animals, and the administration of beta-Ala did not modify this elevation. The association of beta-Ala with MTX-MeOH produced an increase of threonine, and a decrease of 5-hydroxytryptamine (5-HT) in the retina without modifying 5-hydroxyindoleacetic acid, whereas in the hippocampus an elevation of asparagine was observed. We conclude that, in the retina, beta-Ala in combination with MTX-MeOH increased serotonin and decreased dopamine (DA) turnover rate, and resulted in changes in the amino acid balance, that could affect glycinergic activity. On the other hand, in the hippocampus, Asp metabolism could be affected by Tau depletion with beta-Ala.

[The role of blood lipids in the different aetiologies of cerebral infarction]. / Papel de los lípidos sanguíneos en las distintas etiologías del infarto cerebral.

INTRODUCTION: In order to determine the role lipids play in cerebral infarction (CI), the different aetiological subgroups of this disease should first be separated. AIMS AND METHOD: We conducted case control studies to identify whether there is a relation between blood lipid levels and the occurrence of cerebral infarction caused by atheromatosis (CIA). Our study involved a total of 98 patients with cerebral infarction of an atherothrombotic or lacunar aetiopathogenesis that were included in the CIA category. Two control groups were set up: one consisted of 23 patients with non atheromatous cerebral infarction (NACI), which included other aetiologies (cardioembolic, unusual and unspecified), and the other was made up of 101 healthy subjects who had not had a stroke. RESULTS: The group of patients with CIA presented higher average cholesterol rates than the group of subjects with NACI (p= 0.005). Nevertheless, compared to the control group they had higher average levels of cholesterol (p= 0.003), triglycerides (p= 0.011), VLDL (p= 0.028) and LDL (p= 0.000), as well as a higher average atherogenic index (p= 0.028). Furthermore, the average levels of LDL (p= 0.030) and the atherogenic index (p= 0.008) were seen to be statistically higher in the group of subjects with NACI than in the control group. Lastly, it must be pointed out that no differences in the average HDL levels were found between the three groups studied (p= 0.500). The presence of high blood pressure and a history of ischemic heart disease in patients with CI did not modify the variations that were observed in the lipids. CONCLUSIONS: Patients with CIA have a more atherogenic lipid profile than healthy individuals, while subjects with NACI are situated midway between the two groups

Effect of chronic methanol administration on amino acids and monoamines in retina, optic nerve, and brain of the rat.

The clinical and electroretinographic features of chronic methanol intoxication are scarce, and neurotransmitter studies have not been conducted. In addition, most of the studies in the field include results after acute administration. In the present work, a chronic methanol intoxication scheme (2 g/kg/day ip for 2 weeks) was carried out in Sprague-Dawley rats previously depleted of folates with methotrexate. Taurine (2%) in drinking water was also administered in two groups of animals. Blood formate levels were increased in methotrexate-methanol-treated animals with respect to controls (0.98 +/- 0.09 and 0.30 +/- 0.03 mM, respectively). Amino acids and monoamines were determined in plasma and in retina, optic nerve, hippocampus, and posterior cortex by HPLC with fluorescence or electrochemical detection. The main finding was an increased aspartate content in the optic nerve in methotrexate methanol-treated animals. Methanol alone increased glutamate, aspartate, glutamine, taurine, 5-hydroxytryptamine, and 5-hydroxyindoleacetic acid levels in the hippocampus and 5-hydroxytryptamine in the retina. Taurine administration had no significant effect on changes induced by methanol treatment. We concluded that chronic methanol administration produced accumulation of aspartate, an excitotoxic amino acid, in the optic nerve. These findings contribute to the understanding of methanol neurotoxicity and might indicate a relationship between chronic methanol consumption and the development of optic neuropathies.

[Electrophoresis of cerebrospinal fluid proteins in patients with ischemic cerebrovascular disease]. / Electroforesis de proteínas del líquido cefalorraquídeo en pacientes con enfermedad cerebrovascular isquémica.

INTRODUCTION: Cerebral infarction (CI) increases vascular permeability because of a torrent of molecular events that take place. It frequently leads to oedema, haemorrhage and neuronal death. Free radicals and proteases are also formed, which cause lesions in the blood vessels, and microvascular integrity is lost through degradation of the basal lamina and the extracellular matrix. As a result rupture of the blood brain barrier takes place. AIMS. To compare the electrophoretograms of patients with ischemic cerebrovascular disease (ICVD) with those of controls and to link the alterations in the proteinogram with the ICVD subtypes. PATIENTS AND METHODS: The CSF of 55 controls and 136 patients with ICVD was examined. The total protein (TP) concentration was determined and a polyacrylamide gel electrophoretogram was produced using Coomassie blue stain. Parallel to this, serum was prepared for haptoglobin staining. RESULTS: The TP in patients CSF rose to a significantly higher level than that of controls. Blood brain barrier damage (BBBD) was observed in 28.7% of the patients studied with CI and in 10.3% in transient ischemic attacks (TIA), while 16.2% presented oligoclonal bands. There was a difference between the two sexes: men were found to have higher TP levels, lower percentages of prealbumin 1 and more BBBD than women. CONCLUSIONS: BBBD is more frequent in infarctions than in TIA, and is predominant in men with thrombotic cerebral infarction.

[Immunological study of cerebrospinal fluid using a human IgM antiserum produced in Cuba. A preliminary evaluation]. / Estudio inmunológico del líquido cefalorraquídeo con el empleo de un antisuero de IgG humano producido en Cuba. Evaluación preliminar.

INTRODUCTION: The immunological study of cerebrospinal fluid (CSF) is an essential diagnostic tool for evaluating patients with neurological diseases. The quantitative determination of the albumen and immunoglobulin G (IgG) in blood serum and in CSF by single radial immunodiffusion (SRID), together with the calculation of the IgG index to evaluate the presence of intrathecal synthesis of IgG and of the albumen quotient in order to evaluate the state of functioning of the blood brain barrier are essential elements to be evaluated for diagnosis and research in neurological clinical practice, as well as in the follow up of certain neurological diseases such as multiple sclerosis. Specific antiserums from commercial firms such as Boehring, SIGMA, etc. are used for the quantitative determination of IgG and albumen both in blood serum and in CSF by SRID. The high cost and the difficulty in acquiring these immunodiagnostic kits have had an important effect on the diagnostic and research opportunities throughout the country. MATERIALS AND METHODS: In this work we present the preliminary findings of the evaluation of the human IgG antiserum obtained from a ram, by Labex laboratories, for the quantitative determination of IgG in CSF by SRID, in order to find out whether this antiserum is efficient in the quantitative determination of IgG in CSF. RESULTS AND CONCLUSIONS: The studies conducted so far show that this antiserum may be a good candidate for use in immunological studies of CSF. Further work needs to be carried out on its validation in order to resolve the problems involved in immunological studies of CSF that we highlighted above. This would be achieved with an antiserum that is cheaper than those used up to now.

Amino acid levels and ratios in serum and cerebrospinal fluid of patients with optic neuropathy in Cuba.

Twenty-one amino acids were determined in serum and cerebrospinal fluid of 12 patients with endemic, and in the cerebrospinal fluid of 22 patients with epidemic optic neuropathy. For the endemic patients, there was a decrease in aspartate and taurine in the serum with respect to controls. The ratios aspartate/taurine and taurine/valine were decreased, and glutamate/taurine was increased in the serum. Some of the altered amino acid ratios indicate preponderance of excitatory to inhibitory molecules. The ratio with valine corresponded to the decrease in taurine and the maintenance of valine concentration, an amino acid related to anthropometric parameters. A typical malnutrition pattern was not observed, as the levels of essential amino acids were not significantly modified. In the cerebrospinal fluid there were increases in aspartate, glutamate and threonine, the first two probably indicating a neurodegenerative disorder or some type of metabolic alteration, primary or secondary to the disease. The increase in threonine could be related to lipid metabolism, but it is not clear at present. A wide variety of amino acid ratios were increased in the cerebrospinal fluid of patients with endemic optic neuropathy, mainly pointing to an excitatory condition and some metabolic alterations. In the cerebrospinal fluid of patients with epidemic optic neuropathy there was an increase in aspartate and glutamate, and increase in glutamate/taurine, glutamate/glycine, and gamma-aminobutyric acid/glycine ratios. Interesting differences were also observed between patients from different periods of time, but with the same clinical features, and the modifications of amino acid concentrations in the cerebrospinal fluid, such as glutamine, threonine and tryptophan. The present results indicate a disorder in the metabolism of amino acids, support a specific deficit, especially for taurine, an imbalance between excitatory and inhibitory amino acids, and a possible relation to viral infections.