Quantum dot-based assay for Cu(2+) quantification in bacterial cell culture.

A simple and sensitive method for quantification of nanomolar copper with a detection limit of 1.2×10(-10)M and a linear range from 10(-9) to 10(-8)M is reported. For the most useful analytical concentration of quantum dots, 1160µg/ml, a 1/Ksv value of 11µM Cu(2+) was determined. The method is based on the interaction of Cu(2+) with glutathione-capped CdTe quantum dots (CdTe-GSH QDs) synthesized by a simple and economic biomimetic method. Green CdTe-GSH QDs displayed the best performance in copper quantification when QDs of different sizes/colors were tested. Cu(2+) quantification is highly selective given that no significant interference of QDs with 19 ions was observed. No significant effects on Cu(2+) quantification were determined when different reaction matrices such as distilled water, tap water, and different bacterial growth media were tested. The method was used to determine copper uptake kinetics on Escherichia coli cultures. QD-based quantification of copper on bacterial supernatants was compared with atomic absorption spectroscopy as a means of confirming the accuracy of the reported method. The mechanism of Cu(2+)-mediated QD fluorescence quenching was associated with nanoparticle decomposition.

[Transcranial sonography for the diagnosis of Parkinson disease]. / Estudio de correlación clínico-radiológica, sensibilidad y especificidad de ecotomografía transcraneana en enfermedad de Parkinson y otros trastornos del movimiento.

BACKGROUND: The detection of hyperechogenicity of the substantia nigra using trans cranial sonography can be predictive of the diagnosis of Parkinson Disease. AIM: To report an experience with transcranial sonography for the diagnosis of Parkinson disease. Material ana METHODS: One hundred sixteen patients with movement disorders were subjected to a transcranial sonography to detect the presence of hyperechogenicity of the substantia nigra and basal ganglia. Afterwards, two physicians, unaware of the results oft he sonography, examined the patients and reached a clinical diagnosis. The concordance between ultrasound results and the clinical diagnosis was analyzed. RESULTS: In 64 patients, a clinical diagnosis of Parkinson disease was reached. Of these, 52 patients had substantia nigra hyperechogenicity and in 12, it was normal. On the other hand ultrasound was normal in 42 of 43 patients without a clinical diagnosis of Parkinson disease. Therefore the sensitivity and specificity of trans cranial ultrasound for the diagnosis of Parkinson disease was 81 and 97%, respectively. CONCLUSIONS: Transcranial sonography has a good sensitivity and specificity for the diagnosis of Parkinson disease.

ATP steal between cation pumps: a mechanism linking Na+ influx to the onset of necrotic Ca2+ overload.

We set out to identify molecular mechanisms underlying the onset of necrotic Ca(2+) overload, triggered in two epithelial cell lines by oxidative stress or metabolic depletion. As reported earlier, the overload was inhibited by extracellular Ca(2+) chelation and the cation channel blocker gadolinium. However, the surface permeability to Ca(2+) was reduced by 60%, thus discarding a role for Ca(2+) channel/carrier activation. Instead, we registered a collapse of the plasma membrane Ca(2+) ATPase (PMCA). Remarkably, inhibition of the Na(+)/K(+) ATPase rescued the PMCA and reverted the Ca(2+) rise. Thermodynamic considerations suggest that the Ca(2+) overload develops when the Na(+)/K(+) ATPase, by virtue of the Na(+) overload, clamps the ATP phosphorylation potential below the minimum required by the PMCA. In addition to providing the mechanism for the onset of Ca(2+) overload, the crosstalk between cation pumps offers a novel explanation for the role of Na(+) in cell death.

Role of endogenous channels in red blood cells response to their exposure to the pore forming toxin Sticholysin II.

Sticholysin II (St II) is a highly hemolytic cytolysin isolated from the sea anemone Stichodactyla heliantus. The toxin hemolytic action takes place through the formation of channels that provoke an electrolyte unbalance leading to osmotic shock. The lytic event must involve the exchange of electrolytes and the entrance of water, leading to red blood cell disruption. These processes can occur through St II pores and/or the endogenous red blood cells transporters. In order to evaluate the contribution of these channels to water, anion and cation transport, we have measured the hemolysis and K+ efflux rates in the presence of several specific inhibitors. The results obtained in the presence of Hg, an AQP1 blocker, indicate that water transport through these channels is not essential for the occurrence of the lytic process induced by St II. The data also support a partial role of K+ and anion transporters. In particular, they are compatible with a preferential K+ efflux though the K(+)/Cl- co-transport as a response to the promoted swelling. Furthermore, they suggest that chloride influx, a process that can regulate both K+ efflux and lysis, is partially mediated by the endogenous cell transporters, in particular, band-3 anion exchange system being relevant at early stages of the lytic process.

[COMPLICATED PANCREATIC PSEUDOCYST: REPORT OF ONE CASE AND LITERATURE REVIEW] / Pseudoquiste Pancreático Complicado. Reporte de un caso y revisión de la literatura.

We reported a complicated pancreatic pseudocyst (intracystic hemorrhage) seven months after an acute pancreatitis attack. A surgical drainage (internal cystogastrostomy) was carried out with excellent resolution. The clinical, radiological and therapeutic features of pancreatic pseudocysts are reviewed.

[Maternal and fetal morbidity in a group of women with gestational diabetes]. / Morbilidad materna y fetal en un grupo de mujeres con diabetes gestacional.

Normal pregnant women in the second and third trimester were screened to detect gestational diabetes. Using the protocol proposed by the World Health Organization, we identified 33 women whose two hr glucose levels was > 200 mg/dl. Only sixteen women had less than 34 weeks of pregnancy when were seen for the first time at the diabetes clinic, the other seventeen women had more than 34 weeks when they presented to the diabetes clinic. The first group, was called the treated group and the second group was the non-treated group. The main clinical characteristics of these patients, treated vs non-treated, were (X +/- SD): age (years) 33.2 +/- 5.2 (20-40) vs 30.2 +/- 6.5 (20-39), p < 0.05; weeks of pregnancy at diagnosis: 27.9 +/- 4.1 (19-33) vs 36.1 +/- 2.3 (34-40), p < 0.05; weight (Kg): 79.9 +/- 13.1 (61.8-108) vs 87.4 +/- 16.8 (60.8-118), p = NS; length of pregnancy (weeks) 38 +/- 1.3 (36-40) vs 38.4 +/- 1.4 (35-40), p = NS; newborns weight (g): 3,654 +/- 650 (2,475-5,100) vs 3,221 +/- 529 (2,650-4,650), p = NS. There was an intrauterine death of a macrosomic fetus in the non-treated group. There were three macrosomic newborns in the treated group and one in the non-treated group, p = NS. Also, there was a premature newborn of 1,975 g, whose pregnancy was interrupted for acute fetal distress. Delivery by cesarean section occurred in 29 women (87.8%), and it was mainly related to the diabetes diagnosis. The prevalence of macrosomia in the treated group supports the idea that treatment has to be established at least at 24 weeks of pregnancy, to reduce this rate. It is concluded that gestational diabetes is associated to an increase in maternal and fetal morbidity, requiring strict supervision to detect and treat fetal distress and a tight glucose control to decrease the macrosomia rate.

Low-temperature biosynthesis of fluorescent semiconductor nanoparticles (CdS) by oxidative stress resistant Antarctic bacteria.

Bacterial biosynthesis of nanoparticles represents a green alternative for the production of nanostructures with novel properties. Recently, the importance of antioxidant molecules on the biosynthesis of semiconductor fluorescent nanoparticles (quantum dots, QDs) by mesophilic bacteria was reported. The objective of this work was the isolation of psychrotolerant, oxidative stress-resistant bacteria from Antarctica to determine their ability for biosynthesizing CdS QDs at low temperatures. QDs biosynthesis at 15 °C was evaluated by determining their spectroscopic properties after exposing oxidative-stress resistant isolates identified as Pseudomonas spp. to Cd(2+) salts. To characterize the QDs biosynthetic process, the effect of metal exposure on bacterial fluorescence was determined at different times. Time-dependent changes in fluorescence color (green to red), characteristic of QDs, were observed. Electron microscopy analysis of fluorescent cells revealed that biosynthesized nanometric structures localize at the cell periphery. QDs were purified from the bacterial isolates and their fluorescence properties were characterized. Emission spectra displayed classical CdS peaks when excited with UV light. Thiol content, peroxidase activity, lipopolysaccharide synthesis, metabolic profiles and sulfide generation were determined in QDs-producing isolates. No relationship between QDs production and cellular thiol content or peroxidase activity was found. However, sulfide production enhanced CdS QDs biosynthesis. In this work, the use of Antarctic psychrotolerant Pseudomonas spp. for QDs biosynthesis at low temperature is reported for the first time.

Estudio de correlación clínico-radiológica, sensibilidad y especificidad de ecotomografía transcraneana en enfermedad de Parkinson y otros trastornos del movimiento / Transcranial sonography for the diagnosis of Parkinson disease

Background: The detection of hyperechogenicity of the substantia nigra using trans cranial sonography can bepredictive ofthe diagnosis of Parkinson Disease. Aim: To report an experience with transcranial sonography for the diagnosis of Parkinson disease. Material ana Methods: One hundred sixteen patients with movement disorders were subjected to a transcranial sonograpy to detect the presence ofhyper-chogenicity of the substantia nigra and basal ganglia. Afterwards, two physicians, unaware ofthe results ofthe sonography, examined the patients and reached a clinical diagnosis. The concordance between ultrasound results and the clinical diagnosis was analyzed. Results: In 64 patients, a clinical diagnosis of Parkinson disease was reached. Ofthese, 52 patients had substantia nigra hyperechogenicity and in 12, it was normal. On the other hand ultrasound was normal in 42 of43 patients without a clinical diagnosis of Parkinson disease. Therefore the sensitivity and specificity of trans cranial ultrasound for the diagnosis of Parkinson disease was 81 and 97 percent, res-pectively. Conclusions: Transcranial sonography has agood sensitivity and specificity for the diagnosis of Parkinson disease.

Hipotensión ortostática en enfermedad de Parkinson / Orthostatic hypotension in Parkinson's disease

The current concept of Parkinson’s disease comprises a group of non-motor symptoms: neuropsychiatric disorders, sleep disturbances and dysautonomia, among others. Orthostatic hypotension is a frequent problem that impairs the patient’s quality of life. We review the symptoms of this disorder, its pathogeny and the available diagnostic tools. We emphasize the early suspicion and show the treatment options, based on the available evidence and our experience.

Temblor esencial: una revisión crítica / Essential tremor: a critical review

Introduction: Essential tremor is commonly considered as a benign and high prevalence disease; however its study is not systematized even in its definition. Methods: We did a literature review related to essential tremor enhanced with our own experience in this matter. Results: We performed a critical review of different issues of essential tremor from definition to association to others neurological diseases. We focused on controversial points and lesser known issues by a non specialist physician. Discussion: We analyzed the complexity of this disease, its association with other neurological diseases, in particular Parkinson disease and cognitive decline. We proposed different variants ofessential tremor according prognosis. Conclusion: Essential tremor is a heterogeneous disease from clinical and etiological point of view. There are variants with different long term outcome.

Introducción: El temblor esencial es habitualmente considerado una patología benigna y de alta prevalencia, sin embargo su estudio ha sido poco sistematizado, aún en la misma definición del cuadro. Método: Se realiza una revisión de la literatura, enriquecida con la propia experiencia de los autores en el tema. Resultados: Se analizan de manera crítica diversos tópicos relacionados con temblor esencial, desde su definición hasta la asociación con otras patologías neurológicas, haciendo hincapié en puntos de mayor controversia y poco conocidos por el médico no especializado en el tema. Discusión: Se analiza la complejidad del cuadro, su asociación con una serie de patologías neurológicas, en particular enfermedad de Parkinson y deterioro cognitivo, proponiéndose variantes de temblor esencial de acuerdo a su pronóstico. Conclusión: El temblor esencial es un cuadro heterogéneo tanto clínicamente como desde una perspectiva etiológica. Existen variantes con distinto pronóstico a largo plazo.

Diagnóstico premotor de la enfermedad de Parkinson / Premotor diagnosis of Parkinson's disease

Parkinson is a neurodegenerative disease that compromises brain nuclei in an ordered pattern. Only when Sustancia Nigra compromise becomes severe, motor signs are noticed. This occurs late in Parkinson course, so there is a long time period before in which no motor signs are evident. This is “premotor phase” of Parkinson disease. To make diagnosis early in premotor phase, would allow beginning a potential treatment that modify disease course. In this article we discuss clinical picture of premotor phase of Parkinson disease, local reality about ancillary tests to improve diagnosis sensibility of it and we suggest treatment approach.

Energetics of catalysis by ribonucleases: fate of the 2',3'-cyclic phosphodiester intermediate.

Ribonucleases catalyze the hydrolysis of the P-O5' bond in RNA. This reaction occurs in two steps: transphosphorylation of RNA to a 2',3'-cyclic phosphodiester intermediate and hydrolysis of this intermediate to a 3'-phosphomonoester. 31P NMR spectroscopy was used to monitor the accumulation of the 2',3'-cyclic phosphodiester intermediate during the transphosphorylation and hydrolysis reactions catalyzed by various ribonucleases and by small molecules. The intermediate was found to accumulate during catalysis by monomeric bovine pancreatic ribonuclease A (RNase A), a dimer and a trimer of RNase A, bovine seminal ribonuclease, RNase T1, barnase, and RNase 1. These enzymes, which are of widely disparate phylogenetic origin, released rather than hydrolyzed most of the intermediate formed transphosphorylation of RNA. In contrast, the intermediate did not accumulate during catalysis by hydroxide ion or imidazole buffer. In the presence of these small molecules, hydrolysis is faster than transphosphorylation. A trapping experiment was used to assess the throughput of the reaction catalyzed by RNase A. [5,6-3H]Uridylyl-(3'-->5')adenosine was incubated with RNase A in the presence of excess unlabeled uridine 2',3'-cyclic phosphodiester, which dilutes the specific radioactivity of any released cyclic intermediate. Only 0.1% of the RNA substrate was found to be both transphosphorylated and hydrolyzed without dissociating from the enzyme. These results suggest that ribonucleases have evolved primarily to catalyze RNA transphosphorylation and not RNA hydrolysis.

Cefaleas / Headaches

Headache is the most frequent symptom that makes patients to attend a neurologist’s office. Is a very common reason to attend general physician as well, so is very important to know how to do a correct diagnosis between primary and secondary headache and to treat the most frequent ones. This review includes migraine, tension type headache and others, from a clinical perspective, with special focuses on clinical clues that allow clinicians a more specific diagnosis and treatment. We want to emphasize how rational treatment should be prescribed and how to avoid rebound headache and others complications related to certain drugs, in particular ergotamines.

[Calcified embolism of the coronary artery due to the degeneration of a bioprosthesis in the aortic position]. / Embolia calcificada a la arteria coronaria por degeneración de bioprótesis en posición aórtica.

We present a case of arterial coronary embolism by calcified material of a bioprosthesis of bovine pericardium of the INC in aortic position 8 years after its implantation. Echocardiogram and catheterization with coronarography demonstrated prosthetic aortic dysfunction and normal coronaries. The patient complained of stable angor and dyspnea. During coronarography there was an increase of symptoms together with ECG changes and after a few hours with enzymatic increase. The patient was brought urgently to surgery where mitroaortic prosthesis was changed with mechanic prosthesis. As surgical findings: absence of a leaflet of prosthesis in aortic position with free fragmented calcium in periannular region and two remaining leaflet completely calcified, prosthesis in mitral position of normal appearance. We conclude that ischemia or myocardial infarction in presence of normal coronaries in patients with bovine pericardial bioprosthesis in aortic position can be secondary to calcium embolism, originated by mineralization process of a degenerated bioprosthesis several years after its implantation.

[Evaluation of the clinical manifestations in patients with reactions to the rabies vaccine or serum in the Ciego de Avila province (Cuba)]. / Evaluación de las manifestaciones clínicas en pacientes con reacciones a la vacuna o suero antirrábico en la provincia de Ciego de Avila (Cuba).

The present design is a descriptive study in which people bitten by animals, rabies treatment used and the reactions to it are described. The frequency of adverse effects to the vaccine and to the serum are pointed out. The forms of clinical presentation and the clinical symptoms of the reactions observed in the Ciego de Avila province, Cuba, in the period from 1981 to 2001, were evaluated. In this period prevailed the reactions to the heterologous serum and the reactions caused by the human rabies vaccine. Local reactions to the vaccine were more common than the systemic ones. Four neuroparalytic reactions produced by the vaccines were observed. The most frequent symptoms and signs of the patients with reaction to the vaccine were pruritus, rash, localized urticaria, papule in the point of injection and local pain. The clinical manifestations considered as reactions to the heterologous serum that prevailed in the patients were rash in gluteal regions, pruritus, local erythyema and fever. No patient was detected with neurological manifestations caused by the heterologous serum.

Uso de harina de cotiledón de algarrobo (Prosopis chilensis (Mol) Stuntz) como fuente de proteína y fibra dietética en la elaboración de galletas y hojuelas fritas / Use of algarrobo (Prosopis chilensis (Mol) Stuntz) flour as protein and dietary fiber source in cookies and fried chips manufacture

Los aminoácidos limitantes en la proteína de algarrobo chileno son isoleucina, treonina y metionina/cisteina. La mezcla de cereales y leguminosas, permite mejorar el balance aminoacídico, ya que las leguminosas tienen más lisina y los cereales son más ricos en aminoácidos azufrados. Debido al interés nutricional del cotiledón de algarrobo, se evaluó la incorporación de harina de cotiledón de algarrobo (HCA) en la elaboración de “snack” dulces y salados. Se prepararon galletas dulces y hojuelas fritas saladas con 0 por ciento, 10 por ciento y 20 por ciento de HCA. En las harinas se determinó, color, granulometría, humedad, composición proximal, lisina disponible, fibra dietética total, soluble e insoluble. A las galletas y hojuelas se les determinaron las mismas características físicas y químicas (excepto granulometría) que las harinas; además se determinó actividad de agua, peso y dimensiones y se calculó el aporte calórico. Se evaluó la calidad y aceptabilidad sensorial de ambos productos. Destaca el alto contenido de proteínas, lípidos, cenizas, fibra cruda (63,6; 10,2; 4,3 y 4,2 g/100g bms, respectivamente), lisina disponible (62,4 mg/g proteína) y fibra dietética total (24,2 g/100g bms) de la HCA. Tanto en las galletas como en las hojuelas con HCA, aumenta significativamente el contenido de proteínas, lípidos, cenizas, fibra cruda, lisina disponible (desde 15,5 a 19,3 y de 20,3 a 29,6 mg lisina/g proteína, respectivamente) y fibra dietética total (de 1,39 a 2,80 y de 1,60 a 5,60 g/100g bms, respectivamente). Todos los tratamientos de galletas fueron igualmente aceptados (“me gusta mucho”); las hojuelas, con 10 por ciento de HCA presentaron la mayor aceptabilidad (“me gusta medianamente”). Se puede concluir que la incorporación de HCA en la elaboración de galletas y hojuelas fritas aumenta el aporte de lisina disponible, su contenido de proteínas y fibra dietética, mejorando la relación fibra soluble/ insoluble, sin afectar sus características fisicas...

Limiting amino acids of the protein from chilean “algarrobo” are isoleucine, theronine and methionine/cyteine. Cereals and legume blends allow to improve the amino acid balance, since legume have more lysine, and cereals are richer in sulphur amino acids. Due to the nutritional interest of “algarrobo” cotyledons, the use of “algarrobo cotyledon” flour (ACF) in sweet and salty snack manufacture was evaluated. Cookies and fried salty chips with 0 percent, 10 percent and 20 percent ACF were prepared. Flours were analyzed for color, particle size, moisture, proximate composition, available lysine, and soluble, insoluble and total dietary fiber. Cookies and chips were analyzed for the same characteristics (except for particle size); besides there were determined water activity, weight and size of the units, and also, the caloric value was computed. Sensory quality and acceptance of both products were evaluated. It is noticeable the high amount of protein, lipids, ash, crude fiber (63.6; 10.2; 4.3 and 4.2 g/100g dmb, respectively), available lysine (62.4 mg/g protein) and total dietary fiber (24.2 g/100g dmb) of ACF. Both, cookies and chips with ACF, showed a significant increase in the amount of protein, lipids, ash, crude fiber and, available lysine (from 15.5 to 19,3 and from 20.3 a 29.6 mg lisina/g protein, respectively), and total dietary fiber (from 1.39 to 2.80 and from 1.60 a 5.60 g/100g dmb, respectively). All of the cookies trials were well accepted (“I like it very much”); chips with 10 percent of AFC showed the highest acceptance (“I like it”). It can be concluded that the use of ACF in cookies and chips manufacture increases the contribution of available lysine; their protein and dietary fiber content, improving the soluble/insoluble fiber ratio, without affect neither their physical nor their sensory acceptance.