Drought tolerance of sugarcane propagules is improved when origin material faces water deficit.

Drought stress can imprint marks in plants after a previous exposure, leading to plant acclimation and a permissive state that facilitates a more effective response to subsequent stress events. Such stress imprints would benefit plants obtained through vegetative propagation (propagules). Herein, our hypothesis was that the propagules obtained from plants previously exposed to water deficit would perform better under water deficit as compared to those obtained from plants that did not face stressful conditions. Sugarcane plants were grown under well-hydrated conditions or subjected to three cycles of water deficit by water withholding. Then, the propagules were subjected to water deficit. Leaf gas exchange was reduced under water deficit and the propagules from plants that experienced water deficit presented a faster recovery of CO2 assimilation and higher instantaneous carboxylation efficiency after rehydration as compared to the propagules from plants that never faced water deficit. The propagules from plants that faced water deficit also showed the highest leaf proline concentration under water deficit as well as higher leaf H2O2 concentration and leaf ascorbate peroxidase activity regardless of water regime. Under well-watered conditions, the propagules from plants that faced stressful conditions presented higher root H2O2 concentration and higher activity of catalase in roots as compared to the ones from plants that did not experience water shortage. Such physiological changes were associated with improvements in leaf area and shoot and root dry matter accumulation in propagules obtained from stressed plants. Our results suggest that root H2O2 concentration is a chemical signal associated with improved sugarcane performance under water deficit. Taken together, our findings bring a new perspective to the sugarcane production systems, in which plant acclimation can be explored for improving drought tolerance in rainfed areas.

Drought tolerance of sugarcane is improved by previous exposure to water deficit.

Under field conditions, plants are exposed to cycles of dehydration and rehydration during their lifespan. In this study, we hypothesized that sugarcane plants previously exposed to cycles of water deficits will perform better than plants that have never faced water deficits when both are subjected to low water availability. Sugarcane plants were grown in a nutrient solution and exposed to one (1WD), two (2WD) or three (3WD) water deficit cycles. As the reference, plants were grown in a nutrient solution without adding polyethylene glycol. Under water deficits, leaf gas exchange was significantly reduced in 1WD and 2WD plants. However, 3WD plants showed similar CO2 assimilation and lower stomatal conductance compared to the reference plants, with increases in intrinsic water-use efficiency. Abscisic acid concentrations were lower in 3WD plants than in 1WD plants. Our data revealed root H2O2 concentration as an important chemical signal, with the highest root H2O2 concentrations found in 3WD plants. These plants presented higher root dry matter and root:shoot ratios compared to the reference plants, as well as higher biomass production when water was available. Our data suggest that sugarcane plants were able to store information from previous stressful events, with plant performance improving under water deficits. In addition, our findings provide a new perspective for increasing drought tolerance in sugarcane plants under nursery conditions.

Physiological Plasticity Is Important for Maintaining Sugarcane Growth under Water Deficit.

The water availability at early phenological stages is critical for crop establishment and sugarcane varieties show differential performance under drought. Herein, we evaluated the relative importance of morphological and physiological plasticity of young sugarcane plants grown under water deficit, testing the hypothesis that high phenotypic plasticity is associated with drought tolerance. IACSP95-5000 is a high yielding genotype and IACSP94-2094 has good performance under water limiting environments. Plants were grown in rhizotrons for 35 days under three water availabilities: high (soil water matric potential [Ψm] higher than -20 kPa); intermediate (Ψm reached -65 and -90 kPa at the end of experimental period) and low (Ψm reached values lower than -150 kPa). Our data revealed that morphological and physiological responses of sugarcane to drought are dependent on genotype and intensity of water deficit. In general, IACSP95-5000 showed higher physiological plasticity given by leaf gas exchange and photochemical traits, whereas IACSP94-2094 showed higher morphological plasticity determined by changes in leaf area (LA) and specific LA. As IACSP94-2094 accumulated less biomass than IACSP95-5000 under varying water availability, it is suggested that high morphological plasticity does not always represent an effective advantage to maintain plant growth under water deficit. In addition, our results revealed that sugarcane varieties face water deficit using distinct strategies based on physiological or morphological changes. When the effectiveness of those changes in maintaining plant growth under low water availability is taken into account, our results indicate that the physiological plasticity is more important than the morphological one in young sugarcane plants.

Voiding dysfunction in patients with neuromyelitis optica spectrum disorders.

AIMS: We assessed the lower urinary tract symptoms (LUTS) and urodynamic findings in patients with neuromyelitis optica spectrum disorders (NMO-SD), a recently defined neurological disease. METHODS: We prospectively evaluated seven men and 23 women (mean age 41.1 ± 13.5 years) with an established diagnosis of NMO-SD who were invited to participate irrespective of the presence of LUTS. Neurological evaluation was assessed with the Expanded Disability Status Scale (EDSS) and LUTS were evaluated with the Overactive Bladder questionnaire (OAB-V8) and the International Prostate Symptom Score (I-PSS). All patients underwent videourodynamics, transabdominal urinary tract sonography, urine culture, and serum creatinine levels. RESULTS: The mean time of disease duration was 33.8 ± 30.8 months. Neurological evaluation showed a mean EDSS score of 5.3 ± 1.8. The most frequent videourodynamic findings were detrusor-sphincter dyssynergia (DSD) and detrusor overactivity (DO) in 11 (36.6%) patients, DSD without DO in seven (23.3%) and DO without DSD in six (20.0%) patients. Voiding dysfunction assessed by I-PSS and OAB-V8 increased with the degree of neurological impairment (P = 0.018; r = 0.42 and P = 0.006; r = 0.48 respectively). Patients with DSD had higher I-PSS (18.5 ± 11.4 vs 7.0 ± 9.2; P = 0.029) and OAB-V8 scores (22.8 ± 15.8vs 9.1 ± 7.8; P = 0.008), and worse neurological impairment (mean EDSS 5.9 ± 1.8 vs 4.5 ± 1.5; P = 0.027). CONCLUSIONS: Most patients with NMO-SD have LUTS and voiding dysfunction, with DSD and DO as the main urodynamic findings. The severity of the neurological disease is a predictive factor for the occurrence of voiding dysfunction and detrusor-sphincter dyssynergia.

Short-term physiological changes in roots and leaves of sugarcane varieties exposed to H2O2 in root medium.

The aim of this study was to evaluate the differential sensitivity of sugarcane genotypes to H2O2 in root medium. As a hypothesis, the drought tolerant genotype would be able to minimize the oxidative damage and maintain the water transport from roots to shoots, reducing the negative effects on photosynthesis. The sugarcane genotypes IACSP94-2094 (drought tolerant) and IACSP94-2101 (drought sensitive) were grown in a growth chamber and exposed to three levels of H2O2 in nutrient solution: control; 3 mmol L(-1) and 80 mmol L(-1). Leaf gas exchange, photochemical activity, root hydraulic conductance (Lr) and antioxidant metabolism in both roots and leaves were evaluated after 15 min of treatment with H2O2. Although, root hydraulic conductance, stomatal aperture, apparent electron transport rate and instantaneous carboxylation efficiency have been reduced by H2O2 in both genotypes, IACSP94-2094 presented higher values of those variables as compared to IACSP94-2101. There was a significant genotypic variation in relation to the physiological responses of sugarcane to increasing H2O2 in root tissues, being root changes associated with modifications in plant shoots. IACSP94-2094 presented a root antioxidant system more effective against H2O2 in root medium, regardless H2O2 concentration. Under low H2O2 concentration, water transport and leaf gas exchange of IACSP94-2094 were less affected as compared to IACSP94-2101. Under high H2O2 concentration, the lower sensitivity of IACSP94-2094 was associated with increases in superoxide dismutase activity in roots and leaves and increases in catalase activity in roots. In conclusion, we propose a general model of sugarcane reaction to H2O2, linking root and shoot physiological responses.

Neuroinfection survey at a neurological ward in a Brazilian tertiary teaching hospital.

OBJECTIVES: This study was undertaken to characterize the neuroinfection profile in a tertiary neurological ward. INTRODUCTION: Neuroinfection is a worldwide concern and bacterial meningitis, tetanus and cerebral malaria have been reported as the commonest causes in developing countries. METHODS: From 1999 to 2007, all patients admitted to the Neurology Ward of Hospital das Clínicas, São Paulo University School of Medicine because of neuroinfection had their medical records reviewed. Age, gender, immunological status, neurological syndrome at presentation, infectious agent and clinical outcome were recorded. RESULTS: Three hundred and seventy four cases of neuroinfectious diseases accounted for 4.2% of ward admissions and the identification of infectious agent was successful in 81% of cases. Mean age was 40.5 + 13.4 years, 63.8% were male, 19.7% were immunocompromised patients and meningoencephalitis was the most common clinical presentation despite infectious agent. Viruses and bacteria were equally responsible for 29.4% of neuroinfectious diseases; parasitic, fungal and prion infections accounted for 28%, 9.6% and 3.5% respectively. Human immunodeficiency virus (HIV), herpes simplex virus 1 (HSV1), Mycobacterium tuberculosis, Treponema pallidum, Taenia solium, Schistosoma mansoni, Cryptococcus neoformans and Histoplasma capsulatum were the more common infectious pathogens in the patients. Infection mortality rate was 14.2%, of which 62.3% occurred in immunocompetent patients. CONCLUSION: Our institution appeared to share some results with developed and developing countries. Comparison with literature may be considered as quality control to health assistance.

Optical coherence tomography evaluation of retinal nerve fiber layer in longitudinally extensive transverse myelitis.

OBJECTIVE: To compare optical coherence tomography (OCT) measurements on the retinal nerve fiber layer (RNFL) of healthy controls and patients with longitudinally extensive transverse myelitis (LETM) without previous optic neuritis. METHOD: Twenty-six eyes from 26 patients with LETM and 26 control eyes were subjected to automated perimetry and OCT for comparison of RNFL measurements. RESULTS: The mean deviation values from perimetry were significantly lower in patients with LETM than in controls (p<0.0001). RNFL measurements in the nasal quadrant and in the 3-o'clock segment were significantly smaller in LETM eyes than in controls. (p=0.04 and p=0.006, respectively). No significantly differences in other RNFL measurements were found. CONCLUSION: Patients with LETM may present localized RNFL loss, particularly on the nasal side of the optic disc, associated with slight visual field defects, even in the absence of previous episodes of optic neuritis. These findings emphasize the fact that patients with LETM may experience attacks of subclinical optic nerve damage.

Optical coherence tomography evaluation of retinal nerve fiber layer in longitudinally extensive transverse myelitis / Avaliação da camada de fibras nervosas da retina na mielite transversal longitudinalmente extensa usando tomografia de coerência óptica

OBJECTIVE: To compare optical coherence tomography (OCT) measurements on the retinal nerve fiber layer (RNFL) of healthy controls and patients with longitudinally extensive transverse myelitis (LETM) without previous optic neuritis. METHOD: Twenty-six eyes from 26 patients with LETM and 26 control eyes were subjected to automated perimetry and OCT for comparison of RNFL measurements. RESULTS: The mean deviation values from perimetry were significantly lower in patients with LETM than in controls (p<0.0001). RNFL measurements in the nasal quadrant and in the 3-o'clock segment were significantly smaller in LETM eyes than in controls. (p=0.04 and p=0.006, respectively). No significantly differences in other RNFL measurements were found. CONCLUSION: Patients with LETM may present localized RNFL loss, particularly on the nasal side of the optic disc, associated with slight visual field defects, even in the absence of previous episodes of optic neuritis. These findings emphasize the fact that patients with LETM may experience attacks of subclinical optic nerve damage.

OBJETIVO: Comparar as medidas da camada de fibras nervosas da retina (CFNR) usando a tomografia de coerência óptica (TCO) em indivíduos normais e pacientes com mielite transversal longitudinalmente extensa (MTLE) sem episódio prévio de neurite óptica. MÉTODO: Vinte e seis olhos de 26 pacientes com MTLE e 26 olhos normais foram submetidos à campimetria computadorizada e TCO para comparação das medidas da CFNR. RESULTADOS: Valores do parâmetro desvio médio da campimetria computadorizada foram significativamente menores nos pacientes com MTLE do que nos controles (p<0,001). Medidas da CFNR no quadrante nasal e no segmento 3 horas foram significativamente menores nos olhos dos pacientes com MTLE do que nos olhos normais (p=0,04 e p=0,006, respectivamente). Não foi encontrada diferença significante nas outras medidas da CFNR avaliadas. CONCLUSÃO: Pacientes com MTLE podem apresentar perda localizada da CFNR, particularmente na região nasal do disco óptico, associada a defeitos discretos de campo visual, mesmo na ausência de episódio prévio de neurite óptica. Estes achados sugerem que pacientes com MTLE podem apresentar acometimento subclínico do nervo óptico.

Neuroinfection survey at a neurological ward in a Brazilian tertiary teaching hospital

OBJECTIVES: This study was undertaken to characterize the neuroinfection profile in a tertiary neurological ward. INTRODUCTION: Neuroinfection is a worldwide concern and bacterial meningitis, tetanus and cerebral malaria have been reported as the commonest causes in developing countries. METHODS: From 1999 to 2007, all patients admitted to the Neurology Ward of Hospital das Clínicas, São Paulo University School of Medicine because of neuroinfection had their medical records reviewed. Age, gender, immunological status, neurological syndrome at presentation, infectious agent and clinical outcome were recorded. RESULTS: Three hundred and seventy four cases of neuroinfectious diseases accounted for 4.2 percent of ward admissions and the identification of infectious agent was successful in 81 percent of cases. Mean age was 40.5 + 13.4 years, 63.8 percent were male, 19.7 percent were immunocompromised patients and meningoencephalitis was the most common clinical presentation despite infectious agent. Viruses and bacteria were equally responsible for 29.4 percent of neuroinfectious diseases; parasitic, fungal and prion infections accounted for 28 percent, 9.6 percent and 3.5 percent respectively. Human immunodeficiency virus (HIV), herpes simplex virus 1 (HSV1), Mycobacterium tuberculosis, Treponema pallidum, Taenia solium, Schistosoma mansoni, Cryptococcus neoformans and Histoplasma capsulatum were the more common infectious pathogens in the patients. Infection mortality rate was 14.2 percent, of which 62.3 percent occurred in immunocompetent patients. CONCLUSION: Our institution appeared to share some results with developed and developing countries. Comparison with literature may be considered as quality control to health assistance.

Isolated bilateral internuclear ophthalmoplegia after ischemic stroke.

A 63-year-old man suddenly developed an isolated bilateral internuclear ophthalmoplegia (INO). High-resolution brain MRI showed signal abnormalities consistent with acute ischemic stroke limited to the infra-aqueductal region of the midbrain bilaterally. This case offers graphic evidence that stroke can be responsible for an isolated bilateral INO.

Occurrence of nervous system involvement in SIRS.

Systemic inflammatory response syndrome (SIRS) is a medical condition in which the all-organ microcirculation is affected including nervous system. We describe neurological findings in 64 patients with SIRS at Hospital das Clínicas of Sao Paulo University School of Medicine; 45.3% were male and 54.7% female; their age ranged from 16 to 95 years old. SIRS was caused by infection in 68.8% of patients, trauma in 10.9%, burns in 7.8%, and elective surgery in 4.7%. The central nervous system involvement occurred in 56.3% of patients and was characterized as encephalopathy in 75%, seizures in 13.9%, non-epileptic myoclonus in 2.8%, and ischemic stroke in 8.3%. The magnetic resonance imaging, cerebrospinal fluid and electroencephalographic changes were unremarkable in encephalopathic patients. Neuromuscular disorders were diagnosed in 43.7%. Critical ill polyneuropathy was characterized in 57.1%, critical ill myopathy in 32.1%, demyelinating neuropathy in 7.2%, and pure motor neuropathy in 3.6%. Nerve and muscle pathological studies dismissed inflammatory abnormalities. The identification of these conditions has important economic implications and may change the critically ill patients' prognosis.

Identification of human T-lymphotropic virus type I (HTLV-I) subtypes using restricted fragment length polymorphism in a cohort of asymptomatic carriers and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis from São Paulo, Brazil.

Although human T-lymphotropic virus type I (HTLV-I) exhibits high genetic stability, as compared to other RNA viruses and particularly to human immunodeficiency virus (HIV), genotypic subtypes of this human retrovirus have been characterized in isolates from diverse geographical areas. These are currently believed not to be associated with different pathogenetic outcomes of infection. The present study aimed at characterizing genotypic subtypes of viral isolates from 70 HTLV-I-infected individuals from São Paulo, Brazil, including 42 asymptomatic carriers and 28 patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), using restricted fragment length polymorphism (RFLP) analysis of long terminal repeat (LTR) HTLV-I proviral DNA sequences. Peripheral blood mononuclear cell lysates were amplified by nested polymerase chain reaction (PCR) and amplicons submitted to enzymatic digestion using a panel of endonucleases. Among HTLV-I asymptomatic carriers, viral cosmopolitan subtypes A, B, C and E were identified in 73.8%, 7.1%, 7.1% and 12% of tested samples, respectively, whereas among HAM/TSP patients, cosmopolitan A (89.3%), cosmopolitan C (7.1%) and cosmopolitan E (3.6%) subtypes were detected. HTLV-I subtypes were not statistically significant associated with patients' clinical status. We also conclude that RFLP analysis is a suitable tool for descriptive studies on the molecular epidemiology of HTLV-I infections in our environment.

Human T cell lymphotropic virus type 1-associated myelopathy in São Paulo, Brazil. Epidemiologic and clinical features of a university hospital cohort.

We report epidemiologic and clinical features of human T cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis in a Brazilian cohort of 86 patients from a university hospital. Cerebrospinal fluid (CSF) abnormalities and magnetic resonance imaging (MRI) findings were correlated with neurologic signs and symptoms. The patients' mean age at disease onset was 43.2 years and the female to male ratio 1.5:1. Risk factors for retroviral exposure included blood transfusions, sexual transmission and intravenous drug use. Neurologic manifestations consisted mostly of spastic paraparesis, of gradual and asymmetric onset, with increased deep-tendon reflexes. Disability was associated with disease duration. CSF findings included mild mononuclear pleocytosis and elevated protein levels. MRI showed hemispheric areas of high signal intensity in 32.7% and spinal cord atrophy in 5.6% of cases, particularly in patients with longer duration of disease. A high frequency of past blood transfusion (32.6%) suggests that blood-borne infection was an important means of HTLV infection before implementation of screening of blood donors in Brazil.

Identification of Human T-lymphotropic Virus Type I (HTLV-I) Subtypes Using Restrited Fragment Length Polymorphism in a Cohort of Asymptomatic Carriers and Patients with HTLV-I-associated Myelopathy/tropical Spastic Paraparesis from Säo Paulo, Brazil

Although human T-lymphotropic virus type I (HTLV-I) exhibits high genetic stability, as compared to other RNA viruses and particularly to human immunodeficiency virus (HIV), genotypic subtypes of this human retrovirus have been characterized in isolates from diverse geographical areas. These are currently believed not to be associated with different pathogenetic outcomes of infection. The present study aimed at characterizing genotypic subtypes of viral isolates from 70 HTLV-I-infected individuals from Säo Paulo, Brazil, including 42 asymptomatic carriers and 28 patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), using restricted fragment length polymorphism (RFLP) analysis of long terminal repeat (LTR) HTLV-I proviral DNA sequences. Peripheral blood mononuclear cell lysates were amplified by nested polymerase chain reaction (PCR) and amplicons submitted to enzymatic digestion using a panel of endonucleases. Among HTLV-I asymptomatic carriers, viral cosmopolitan subtypes A, B, C and E were identified in 73.8 percent, 7.1 percent, 7.1 percent and 12 percent of tested samples, respectively, whereas among HAM/TSP patients, cosmopolitan A (89.3 percent), cosmopolitan C (7.1 percent) and cosmopolitan E (3.6 percent) subtypes were detected. HTLV-I subtypes were not statistically significant associated with patients' clinical status. We also conclude that RFLP analysis is a suitable tool for descriptive studies on the molecular epidemiology of HTLV-I infections in our environment

Susceptibilidade à hipertermia maligna em três pacientes com síndrome maligna por neurolépticos / Malignant hyperthermia susceptibility in three patients with malignant neuroleptic syndrome

A hipertermia maligna caracteriza-se por hipertermia, rigidez muscular, rabdomiólise, acidose e insuficiência de múltiplos órgaos. A hipertermia maligna anestésica decorre da exposiçao a halogenados e/ou relaxantes musculares despolarizantes. O método padrao para diagnosticar a suscetibilidade à hipertermia maligna é o teste da contratura muscular in vitro em resposta ao halotano e à cafeína. A síndrome maligna por neurolépticos caracteriza-se por hipertermia, síndrome extrapiramidal, acidose, instabilidade neurovegetativa e alteraçoes neurológicas. Descrevemos três pacientes com síndrome maligna por neurolépticos e testes de contratura muscular positivos. Esse achado demonstra que ocasionalmente o músculo de pacientes com síndrome maligna por neurolépticos pode mostrar as alteraçoes encontradas na hipertermia maligna anestésica