El pico flujo espiratorio y la cuenta máxima son marcadores del compromiso respiratorio en la miastenia gravis / Peak expiratory flow and the single-breath counting test as markers of respiratory function in patients with myasthenia gravis

Introducción: La miastenia gravis (MG) es una enfermedad autoinmune mediada por anticuerpos. El cuadro clínico se caracteriza por debilidad muscular fluctuante y fatigable, con frecuente afectación de músculos fonodeglutorios y respiratorios. Dada la severidad que implica el compromiso respiratorio en la MG, su evaluación rutinaria es esencial.Nuestro objetivo fue identificar un marcador semiológico útil en la pesquisa del compromiso respiratorio en pacientes con MG.Métodos: Se realizó un trabajo observacional en pacientes con diagnóstico de MG. Los pacientes fueron evaluados con test de cuenta máxima, pico flujo espiratorio (PEF), cuestionario de disnea modificado (mMRC) y valoración de fuerza del cuello. Los resultados de estos parámetros fueron correlacionados con la medición de CVF (capacidad vital forzada) y presiones bucales estáticas máximas (PiMáx y PeMáx). Resultados:Cuarenta y cinco pacientes con MG fueron incluidos, dos pacientes tenían MGFA grado I, 35 grado II, siete grado III y uno grado IV al momento de la evaluación. Se halló una correlación positiva entre el test de cuenta máxima y la CVF (r = 0,57, p = 0,000), y entre el PEF y la CVF (r = 0,76, p = 0,000). El grado de disnea, según el mMRC, mostró una correlación negativa con la CVF (r =-0,31 p = 0,03). A su vez, el PEF correlacionó con la PeMáx de forma positiva, estadísticamente significativa (r = 0,51, p = 0,002).Conclusiones: El PEF, el test de cuenta máxima y el mMRC fueron útiles para evaluar la función respiratoria en pacientes con MG.(AU)

Introduction: Myasthenia gravis (MG) is an antibody-mediated autoimmune disease characterised by fluctuating, fatigable muscle weakness, frequently involving bulbar and respiratorymuscles. Considering the severity of respiratory involvement in MG, routine evaluation ofrespiratory function is essential.The aim of this study was to identify a useful clinical marker of respiratory involvement inpatients with MG. Methods: We performed an observational study of patients with MG. All cases were evaluatedwith the single-breath counting test, peak expiratory flow (PEF), a modified Medical ResearchCouncil dyspnoea scale (mMRC), and a neck strength assessment. The results of these parameters were correlated with forced vital capacity (FVC), maximal inspiratory pressure (MIP), andmaximal expiratory pressure (MEP). Results: The study included 45 patients with MG: 2 patients classified as grade I on the Myasthenia Gravis Foundation of America classification at the time of evaluation, 35 classified asgrade II, 7 classified as grade III, and one classified as grade IV. Positive correlations were foundbetween single-breath counting test scores and FVC values (r = 0.57, p = .000), and betweenPEF and FVC values (r = 0.76, p = .000). Severity of dyspnoea according to the mMRC scaleshowed a negative correlation with FVC values (r = -0.31, p = .03). PEF also showed a significantcorrelation with MEP (r = 0.51, p = .002). Conclusions: PEF, the single-breath counting test, and the mMRC scale are useful measures forevaluating respiratory function in patients with MG.(AU)

Peak expiratory flow and the single-breath count test as markers of respiratory function in patients with myasthenia gravis.

INTRODUCTION: Myasthenia gravis (MG) is an antibody-mediated autoimmune disease characterised by fluctuating, fatigable muscle weakness, frequently involving bulbar and respiratory muscles. Considering the severity of respiratory involvement in MG, routine evaluation of respiratory function is essential. The aim of this study was to identify a useful clinical marker of respiratory involvement in patients with MG. METHODS: We performed an observational study of patients with MG. All cases were evaluated with the single-breath count test, peak expiratory flow (PEF), a modified Medical Research Council dyspnoea scale (mMRC), and a neck strength assessment. The results of these parameters were correlated with forced vital capacity (FVC), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP). RESULTS: The study included 45 patients with MG: 2 patients classified as grade I on the Myasthenia Gravis Foundation of America classification at the time of evaluation, 35 classified as grade II, 7 classified as grade III, and one classified as grade IV. Positive correlations were found between single-breath count test scores and FVC values (r = 0.57, P = .000), and between PEF and FVC values (r = 0.76, P = .000). Severity of dyspnoea according to the mMRC scale showed a negative correlation with FVC values (r = -0.31, P = .03). PEF also showed a significant correlation with MEP (r = 0.51, P = .002). CONCLUSIONS: PEF, the single-breath count test, and the mMRC scale are useful measures for evaluating respiratory function in patients with MG.

Peak expiratory flow and the single-breath counting test as markers of respiratory function in patients with myasthenia gravis. / El pico flujo espiratorio y la cuenta máxima son marcadores del compromiso respiratorio en la miastenia gravis.

INTRODUCTION: Myasthenia gravis (MG) is an antibody-mediated autoimmune disease characterised by fluctuating, fatigable muscle weakness, frequently involving bulbar and respiratory muscles. Considering the severity of respiratory involvement in MG, routine evaluation of respiratory function is essential. The aim of this study was to identify a useful clinical marker of respiratory involvement in patients with MG. METHODS: We performed an observational study of patients with MG. All cases were evaluated with the single-breath counting test, peak expiratory flow (PEF), a modified Medical Research Council dyspnoea scale (mMRC), and a neck strength assessment. The results of these parameters were correlated with forced vital capacity (FVC), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP). RESULTS: The study included 45 patients with MG: 2 patients classified as grade I on the Myasthenia Gravis Foundation of America classification at the time of evaluation, 35 classified as grade II, 7 classified as grade III, and one classified as grade IV. Positive correlations were found between single-breath counting test scores and FVC values (r = 0.57, p = .000), and between PEF and FVC values (r = 0.76, p = .000). Severity of dyspnoea according to the mMRC scale showed a negative correlation with FVC values (r = -0.31, p = .03). PEF also showed a significant correlation with MEP (r = 0.51, p = .002). CONCLUSIONS: PEF, the single-breath counting test, and the mMRC scale are useful measures for evaluating respiratory function in patients with MG.

Cadmium elicits alterations in mitochondrial morphology and functionality in C3H10T1/2Cl8 mouse embryonic fibroblasts.

BACKGROUND: Cadmium is a widespread carcinogen. We previously showed that the administration of low CdCl2 doses for 24 h to healthy C3H10T1/2Cl8 mouse embryonic fibroblast cell line at the beginning of Cell Transformation Assay (CTA), up regulates genes involved in metal scavenging and antioxidant defense, like metallothioneines, glutathione S-transferases and heat shock proteins. Still, although most cells thrive normally in the following weeks, malignancy is triggered by CdCl2 and leads to the appearance of foci of transformed cells at the end of the CTA. In this work we aim at elucidating the early metabolic deregulation induced by cadmium, underlying healthy cell transformation into malignant cells. METHODS: Respiratory metabolism was investigated through Seahorse Agilent assays, while oxidative stress level was assessed through fluorescent probes; DNA damage was evaluated by Comet assay, and mitochondrial morphology was analyzed in confocal microscopy. RESULTS: Results show that the initial response to CdCl2 involves mitochondria rearrangement into a perinuclear network. However, SOD1 and SOD2 activities are inhibited, leading to increased superoxide anion level, which in turn causes DNA strand breaks. From the metabolic point of view, cells increase their glycolytic flux, while all extra NADH produced is still efficiently reoxidized by mitochondria. CONCLUSIONS: Our results confirm previously shown response against cadmium toxicity; new data about glycolytic increase and mitochondrial rearrangements suggest pathways leading to cell transformation. GENERAL SIGNIFICANCE: In this work we exploit the widely used, well known CTA, which allows following healthy cells transformation into a malignant phenotype, to understand early events in cadmium-induced carcinogenesis.

Chagas disease knocks on our door: a cross-sectional study among Latin American immigrants in Milan, Italy.

OBJECTIVES: We aimed to assess the prevalence and risk factors for Chagas disease (CD) in Latin American immigrants and to evaluate the accuracy of diagnostic tests. Moreover, we offered to all positive subjects a complete free-of-charge clinical/instrumental evaluation as well as benznidazole treatment in order to stage the disease and verify drug tolerability. METHODS: A cross-sectional survey of CD among Latin Americans living in Milan and its metropolitan area was conducted between July 2013 and July 2014. Blood samples were tested for serologic evidence of CD together with a questionnaire covering demographic and clinical-epidemiological information. RESULTS: Forty-eight (9.6%) of the 501 tested subjects were conclusively diagnosed as having CD. The highest prevalence of CD was among those from Bolivia (43/169, 25.4%) and El Salvador (4/68, 5.9%). Older age (adjusted odds ratio (aOR)] 1.05, p =0.004), a Bolivian origin (aOR 8.80; p =0.003), being born in the department of Santa Cruz (aOR 3.72, p =0.047), having lived in mud houses (aOR 2.68; p =0.019), and having an affected relative (aOR 12.77, p =0.001) were independently associated with CD. The ARCHITECT Chagas test showed the highest sensitivity (100%) and specificity (99.8%). Twenty-nine of the subjects with CD (60.4%) underwent disease staging, 10 of whom (35.7%) showed cardiac and/or digestive involvement. Benznidazole treatment was associated with high frequency of adverse reactions (19/27, 70.4%) and permanent discontinuation (8/27, 29.6%). CONCLUSIONS: CD is highly prevalent among Bolivians and Salvadorans living in Milan. Regions with a large Latin American immigrant population should implement programmes of active detection and treatment.

Estimating gestational age at birth from fundal height and additional anthropometrics: a prospective cohort study.

OBJECTIVE: Accurate assessment of gestational age (GA) is critical to paediatric care, but is limited in developing countries without access to ultrasound. Our objectives were to assess the accuracy of prediction of GA at birth and preterm birth classification using routinely collected anthropometry measures. DESIGN: Prospective cohort study. SETTING: United States. POPULATION OR SAMPLE: A total of 2334 non-obese and 468 obese pregnant women. METHODS: Enrolment GA was determined based on last menstrual period, confirmed by first-trimester ultrasound. Maternal anthropometry and fundal height (FH) were measured by a standardised protocol at study visits; FH alone was additionally abstracted from medical charts. Neonatal anthropometry measurements were obtained at birth. To estimate GA at delivery, we developed three predictor models using longitudinal FH alone and with maternal and neonatal anthropometry. For all predictors, we repeatedly sampled observations to construct training (60%) and test (40%) sets. Linear mixed models incorporated longitudinal maternal anthropometry and a shared parameter model incorporated neonatal anthropometry. We assessed models' accuracy under varied scenarios. MAIN OUTCOME MEASURES: Estimated GA at delivery. RESULTS: Prediction error for various combinations of anthropometric measures ranged between 13.9 and 14.9 days. Longitudinal FH alone predicted GA within 14.9 days with relatively stable prediction errors across individual race/ethnicities [whites (13.9 days), blacks (15.1 days), Hispanics (15.5 days) and Asians (13.1 days)], and correctly identified 75% of preterm births. The model was robust to additional scenarios. CONCLUSIONS: In low-risk, non-obese women, longitudinal FH measures alone can provide a reasonably accurate assessment of GA when ultrasound measures are not available. TWEETABLE ABSTRACT: Longitudinal fundal height alone predicts gestational age at birth when ultrasound measures are unavailable.

Psychiatric comorbidities and suicidality among patients with neuromyelitis optica spectrum disorders in Argentina.

BACKGROUND: Neuromyelitis optica is a relapsing inflammatory, secondarily demyelinating astrocytopathy that most commonly affects the optic nerves and the spinal cord. OBJECTIVE: This study aimed to evaluate the psychopathological profile, presence of current depression, and suicidality in patients with neuromyelitis optica spectrum disorders (NMOSD) in an Argentinean cohort, and compare these parameters to those in patients with multiple sclerosis (MS) and in healthy controls (HCs). METHODS: Twenty patients with NMOSD, 18 with MS, and 20 healthy controls were included. The presence and grade of current depression were assessed using Beck's depression inventory (BDI), while psychiatric disease and suicidality were assessed using the Mini-International Neuropsychiatric Interview. RESULTS: The prevalence of psychiatric disease in the NMOSD group was 45%, significantly higher than in the MS group (16%, p = 0.06) and the HCs (5%, p = 0.008). Recurrent major depressive disorder was the most frequent psychiatric disease and was diagnosed in four (20%) patients in the NMOSD group and in two (11%) patients in the MS group. In the NMOSD group, two (10%) patients were diagnosed with past manic episodes, one (5%) with current dysthymic disorder, one (5%) with lifetime psychotic disorder, and one (5%) with bulimia nervosa. One patient (5.5%) in the MS group and one in the HC (5%) were diagnosed with current generalized anxiety disorder. Ten patients (50%) in the NMOSD group had current depressive symptoms versus five (28%) patients in the MS group (p = 0.16) and two (10%) in the HC group (p = 0.02). Six (30%) patients with NMOSD versus only one (5.5%) patient with MS had attempted suicide at least once, this difference was statistically significant (p = 0.05). Current suicide risk was high in patients with NMOSD (8, 40%) and moderate in patients with MS (4, 22%). CONCLUSIONS: Our study shows that the prevalence of psychiatric comorbidities in patients with NMOSD is significantly higher than in patients with MS and healthy controls. Given the high frequency of suicidality, assessment of pertinent psychiatric disorders in such patients to optimize monitoring and comprehensive treatment is required.

Aspirin triggered-lipoxin A4 reduces the adhesion of human polymorphonuclear neutrophils to endothelial cells initiated by preeclamptic plasma.

INTRODUCTION: Preeclampsia is a disorder of pregnancy, characterized by hypertension and proteinuria after 20 weeks of gestation. Here, we evaluated the role of aspirin triggered-lipoxin A(4) (ATL, 15-epi-LXA(4)) on the modulation of the adhesion of human polymorphonuclear neutrophils (PMN) to endothelial cells initiated by preeclamptic plasma. MATERIALS AND METHODS: Plasma from preeclamptic, normotensive pregnant, and non-pregnant women were analyzed for factors involved in regulating angiogenesis, inflammation and lipid peroxidation. Plasma from preeclamptic women was added to human umbilical vein endothelial cells, and the adhesion of PMN (incubated with or without ATL) to cells was evaluated. RESULTS: Preeclampsia was associated with some augmented anti-angiogenic, oxidative and pro-inflammatory markers, as well as increasing human PMN-endothelial cell adhesion. This cell adhesion was reduced when human PMN were incubated with ATL prior to addition to endothelial monolayers. DISCUSSIONS AND CONCLUSIONS: Our results are the starting point for further research on the efficacy and rational use of aspirin in preeclampsia.

Myasthenia gravis and neuromyelitis optica spectrum disorder: a multicenter study of 16 patients.

OBJECTIVE: To describe 16 patients with a coincidence of 2 rare diseases: aquaporin-4 antibody (AQP4-Ab)-mediated neuromyelitis optica spectrum disorder (AQP4-NMOSD) and acetylcholine receptor antibody (AChR-Ab)-mediated myasthenia gravis (AChR-MG). METHODS: The clinical details and antibody results of 16 patients with AChR-MG and AQP4-NMOSD were analyzed retrospectively. RESULTS: All had early-onset AChR-MG, the majority with mild generalized disease, and a high proportion achieved remission. Fifteen were female; 11 were Caucasian. In 14/16, the MG preceded NMOSD (median interval: 16 years) and 11 of these had had a thymectomy although 1 only after NMOSD onset. In 4/5 patients tested, AQP4-Abs were detectable between 4 and 16 years prior to disease onset, including 2 patients with detectable AQP4-Abs prior to thymectomy. AChR-Abs decreased and the AQP4-Ab levels increased over time in concordance with the relevant disease. AChR-Abs were detectable at NMOSD onset in the one sample available from 1 of the 2 patients with NMOSD before MG. CONCLUSIONS: Although both conditions are rare, the association of MG and NMOSD occurs much more frequently than by chance and the MG appears to follow a benign course. AChR-Abs or AQP4-Abs may be present years before onset of the relevant disease and the antibody titers against AQP4 and AChR tend to change in opposite directions. Although most cases had MG prior to NMOSD onset, and had undergone thymectomy, NMOSD can occur first and in patients who have not had their thymus removed.

Early onset of allergic rhinitis and asthma in recent extra-European immigrants to Milan, Italy: the perspective of a non-governmental organisation.

BACKGROUND: Allergy is determined by genetic and environmental factors. People immigrating from under-developed to industrialised countries are at higher risk of developing allergic diseases and immigration is as a good epidemiological model to quantify the influence of the environment. We performed the allergological assessment of 32,555 recent immigrants from different areas of the world to a polluted metropolitan area of Northern Italy. METHODS: We evaluated time of onset of allergic rhinitis and/or asthma, sensitisations and clinical characteristics of 395 subjects (3.74 ± 2.94 yrs, mean ± SD) from four macro-areas (Asia, Africa, East-Europe, South America) arriving to Milan, Italy from June 2005 to June 2009. Data were compared with immigrants having access to the same medical facility for any medical problem and with resident Italians living in the same area. RESULTS: Immigrants with allergic rhinitis and/or asthma days since arrival in Italy correlated with number of sensitisations (p=0.0030). Moreover, personal (2.02%) or familial (2.78%) history of allergic diseases was lower in allergic immigrants as compared to allergic residents (37.77 and 29.39%, respectively; p<0.0001 for both comparisons). Finally, the frequency of allergic immigrants from South America (63.3%) was higher than expected from the overall proportion of individuals from this macro-area who sought medical help at the same facility (40.4%; p<0.0001, OR 2.289, CI 2.1670-3.255). CONCLUSIONS: Environmental factors play a relevant role in the induction of allergies in immigrants to Northern Italy. Genetics appears as a further promoting factor in the case of immigrants from South America.

Interferon-gamma releasing assay versus tuberculin skin testing for latent tuberculosis infection in targeted screening programs for high risk immigrants.

BACKGROUND: Recent immigrants from developing countries (<2 years since immigration) are at very high risk of active TB disease due to reactivation of latent infections acquired in the country of origin. In industrialized low-incidence TB countries targeted testing programs for high risk groups could allow the detection of latently infected persons who would likely benefit from a course of preventive treatment. In this study we evaluated the tuberculin skin test (TST) and interferon-gamma enzyme-linked immunosorbent assay (QuantiFERON TB-gold in tube, QFT-IT) strategies for TB infection screening programs in recent immigrants from highly endemic countries. PATIENTS AND METHODS: This is a prospective cross-sectional study. Paired tests performed in 1,130 immigrants attending an outpatient ward, between 2005 and 2007 for any health problem were evaluated by intention-to-treat (ITT) and per-protocol (PP) analysis for efficiency and efficacy of screening program. RESULTS: Positive TST and QFT-IT were observed in 36.04 versus 29.82% (ITT) and in 45.27 versus 30.22% (PP) respectively. A higher drop-out rate was observed for TST (20.35 vs. 1.33%) (p < 0.0001). Second level assessment was accepted by half of the TST positive patients. Overall agreement rate between 887 paired tests was fair (k = 0.38). Higher k values were observed for higher TB prevalence rate in the country of origin (k = 0.43), for TST induration diameters >20 mM (k = 0.47), in subjects aged 40-50 years (k = 0.41) and in unvaccinated persons (k = 0.40). In a multiple logistic regression model continent of origin, class of TB prevalence in the country of origin and contacts with TB patients were found to be significantly associated with the probability of TST and QFT-IT positive result. Low education levels were associated only to an increased risk of TST positive results. CONCLUSIONS: The drawback of the TST screening strategy in recent immigrants from highly endemic countries is due to low sensitivity/specificity of the test and to high drop-out rate with an overall significant lowering in strategy efficacy/efficiency. The higher QFT-IT specificity prevents unnecessary overload of the health care system and, although more expensive, might represent a cost-effective alternative to TST in targeted screening programs directed to high risk populations.

[Influence of the male genomic imprinting on the reproduction]. / Influencia de la impronta genómica masculina en la reproducción.

OBJECTIVE: Genomic imprinting is the epigenetic change that occurred differentially in the specific genes in spermatozoa and oocyte according to their paternal or maternal origin, thus allowing a monoallelic expression. This review is a critical analysis of the published information relating to the role of the male imprinting on the successful reproduction. METHODS: We performed a literature search on some of the components that regulate the male genomic imprinting and the possible role on reproductive events such as spermatogenesis, and placental and embryo development. RESULTS: The literature analysis allowed us to appreciate structural, genetic and epigenetic changes occurring during the formation of the male gamete that could have an impact on embryo development, mainly in the formation of extraembryonic tissues as the placenta. CONCLUSION: Alterations in the molecular mechanisms involved in the sperm DNA methylation during the spermatogenesis, could induce alterations in the normal pattern of expression required in the fetal-placental components development.

[Reversible posterior leucoencephalopathy syndrome: a case report and review of its physiopathology based on neuroradiological findings]. / Leucoencefalopatia posterior reversible: descripcion de un caso y revision de la fisiopatologia basada en hallazgos neurorradiologicos.

INTRODUCTION: Reversible posterior leucoencephalopathy is a clinico radiological syndrome first described in the last decade. The physiopathological mechanism governing it is not very well known. The currently accepted hypotheses are the generation of a vasogenic edema caused by failure of the mechanism that allows self regulation of the cerebral blood flow, and the production of a cytotoxic edema due to ischemia. Both experimental studies carried out in rats and the use of magnetic resonance imaging (MRI) to evaluate the diffusion of cerebral water support the first hypothesis. We report the case of a patient with reversible posterior leucoencephalopathy syndrome that was complicated by areas of cerebral infarction and we review the physiopathological mechanisms involved, basing our analysis on the findings obtained with MRI. CASE REPORT: A female patient was admitted to our hospital because of bilateral transient amaurosis, headaches, vomiting and arterial hypertension. MRI brain scans showed bilateral cortico subcortical lesions in the occipital parietal regions, frontal and right cerebellar hemisphere convexity, with hyperintense signal in T2 and diffusion weighted imaging. Some occipital parietal regions present a diminished signal on the apparent diffusion coefficient map. The patient was treated with intravenous antihypertensive drugs and full recovery was accomplished within 10 days. A month later, according to MRI scans, there were still hyperintense areas in T2 on both occipital lobes, which were compatible with cerebral infarcts. DISCUSSION: The mechanism that is most frequently involved in this entity is probably vasogenic edema. In our case there were, at the same time, areas of cytotoxic edema that progressed to cerebral infarcts. MRI with sequences that evaluate the diffusion of cerebral water is useful in distinguishing between the two mechanisms.

High affinity as a disease determinant factor in anti-GM(1) antibodies: comparative characterization of experimentally induced vs. disease-associated antibodies.

Elevated titers of serum anti-GM(1) antibodies of IgG isotype are found frequently in patients with Guillain-Barré syndrome. Much evidence indicates that these autoantibodies are involved in disease progression, but their exact function and the mechanism of their appearance are still unclear. In an attempt to reproduce "ganglioside syndrome", the experimental model of neuropathy developed by Nagai et al. (Neurosci. Lett. 2 (1976) 107), rabbits were intensively immunized with GM(1) in complete Freund adjuvant (CFA). High titers of anti-GM(1) antibodies were produced, with class switch and affinity maturation indicating an elaborate immune response. Unexpectedly, the rabbits did not show any clinical symptoms of neuropathy. Relatively affinities of both IgM and IgG antibodies were significantly lower than those of similar antibodies from neuropathy patients. These results suggest the existence of a threshold value above which affinity of anti-GM(1) antibodies becomes an important factor in disease induction. The absence of neuropathy symptoms in rabbits may be explained by absence of these high-affinity anti-GM(1) antibodies.

Insuficiencia respiratoria aguda tras artroscopia de rodilla bajo isquemia neumática / Acute respiratory insufficiency after knee arthroscopy with tourniquet pressure

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Novel dermatologic uses of the immune response modifier imiquimod 5% cream.

Imiquimod is the first of a new class of drugs to emerge in the treatment of various dermatologic disorders. As an immune response modifier, it has been shown to have potent antiviral and antitumor properties through the stimulation of innate and cell mediated immune pathways. It is currently approved for the treatment of external genital and perianal warts, but has also been found to be an effective treatment for a host of other virus-associated dermatologic lesions, including common and flat warts, molluscum contagiosum and herpes simples 2. Oncological lesions showing improvement with the use of imiquimod include basal cell carcinoma, actinic keratosis, squamous cell carcinoma in situ, malignant melanoma, cutaneous T-cell lymphoma, and cutaneous extramammary Paget's disease. Recent case studies have also found this product to be effective for treating keloids, infantile hemangiomas, porokeratosis of Mibelli, leishmanisis, and tattoo removal. This extensive array of disorders treated successfully with imiquimod warrants further study of this novel and valuable drug.

Variable patterns of anti-GM(1) IgM-antibody populations defined by affinity and fine specificity in patients with motor syndromes: evidence for their random origin.

Elevated titers of serum antibodies against GM(1)-ganglioside are associated with a variety of autoimmune neuropathies. Although much evidence indicates that these autoantibodies play a primary role in the disease processes, the mechanism of their appearance is unclear. Low-affinity anti-GM(1) antibodies of the IgM isotype are part of the normal human immunological repertoire. In patients with motor syndromes, we found that in addition to the usual anti-GM(1) antibodies, the sera contain IgM-antibodies that recognize GM(1) with higher affinity and/or different specificity. This latter type of antibodies was not detected in other autoimmune diseases. We studied the fine specificity of both normal and motor disease-associated antibodies using HPTLC-immunostaining of GM(1) and structurally related glycolipids, soluble antigen binding inhibition, and GM(1) affinity columns. Normal low-affinity anti-GM(1) antibodies cross-react with GA(1) and/or GD(1b). In the motor syndrome patients, different populations of antibodies characterized by their affinity and cross-reactivity were detected. Although one population is relatively common (low affinity, not cross-reacting with GA(1) and GD(1b)), there are remarkably few sera having the same set of populations. These results suggest that the appearance of the new antibody populations is a random process. When the different antibody populations were analyzed in relation to the three-dimensional structure of GM(1), a restricted area of the GM(1) oligosaccharide (the terminal Galbeta1-3GalNAc) was found to be involved in binding of normal anti-GM(1) antibodies. Patient antibodies recognize slightly different areas, including additional regions of the GM(1) molecule such as the NeuNAc residue. We hypothesize that disease-associated antibodies may originate by spontaneous mutation of normal occurring antibodies.

Investigating microbial (micro)colony heterogeneity by vibrational spectroscopy.

Fourier transform infrared and Raman microspectroscopy are currently being developed as new methods for the rapid identification of clinically relevant microorganisms. These methods involve measuring spectra from microcolonies which have been cultured for as little as 6 h, followed by the nonsubjective identification of microorganisms through the use of multivariate statistical analyses. To examine the biological heterogeneity of microorganism growth which is reflected in the spectra, measurements were acquired from various positions within (micro)colonies cultured for 6, 12, and 24 h. The studies reveal that there is little spectral variance in 6-h microcolonies. In contrast, the 12- and 24-h cultures exhibited a significant amount of heterogeneity. Hierarchical cluster analysis of the spectra from the various positions and depths reveals the presence of different layers in the colonies. Further analysis indicates that spectra acquired from the surface of the colonies exhibit higher levels of glycogen than do the deeper layers of the colony. Additionally, the spectra from the deeper layers present with higher RNA levels than the surface layers. Therefore, the 6-h colonies with their limited heterogeneity are more suitable for inclusion in a spectral database to be used for classification purposes. These results also demonstrate that vibrational spectroscopic techniques can be useful tools for studying the nature of colony development and biofilm formation.