Association of furanone C-30 with biofilm formation & antibiotic resistance in Pseudomonas aeruginosa

Background & objectives: Pseudomonas aeruginosa is an opportunistic pathogen that can cause nosocomial bloodstream infections in humans. This study was aimed to explore the association of furanone C-30 with biofilm formation, quorum sensing (QS) system and antibiotic resistance in P. aeruginosa. Methods: An in vitro model of P. aeruginosa bacterial biofilm was established using the standard P. aeruginosa strain (PAO-1). After treatment with 2.5 and 5 ?g/ml of furanone C-30, the change of biofilm morphology of PAO-1 was observed, and the expression levels of QS-regulated virulence genes (lasB, rhlA and phzA2), QS receptor genes (lasR, rhlR and pqsR) as well as QS signal molecule synthase genes (lasI, rhlI, pqsE and pqsH) were determined. Besides, the AmpC expression was quantified in planktonic and mature biofilm induced by antibiotics. Results: Furanone C-30 treatment significantly inhibited biofilm formation in a dose-dependent manner. With the increase of furanone C-30 concentration, the expression levels of lasB, rhlA, phzA2, pqsR, lasI, rhlI pqsE and pqsH significantly decreased in mature biofilm bacteria while the expression levels of lasR and rhlR markedly increased. The AmpC expression was significantly decreased in both planktonic and biofilm bacteria induced by imipenem and ceftazidime. Interpretation & conclusions: Furanone C-30 may inhibit biofilm formation and antibiotic resistance in P. aeruginosa through regulating QS genes. The inhibitory effect of furanone C-30 on las system appeared to be stronger than that on rhl system. Further studies need to be done with different strains of P. aeruginosa to confirm our findings.

Detection of acute cerebral hemorrhage in rabbits by magnetic induction

Acute cerebral hemorrhage (ACH) is an important clinical problem that is often monitored and studied with expensive devices such as computed tomography, magnetic resonance imaging, and positron emission tomography. These devices are not readily available in economically underdeveloped regions of the world, emergency departments, and emergency zones. We have developed a less expensive tool for non-contact monitoring of ACH. The system measures the magnetic induction phase shift (MIPS) between the electromagnetic signals on two coils. ACH was induced in 6 experimental rabbits and edema was induced in 4 control rabbits by stereotactic methods, and their intracranial pressure and heart rate were monitored for 1 h. Signals were continuously monitored for up to 1 h at an exciting frequency of 10.7 MHz. Autologous blood was administered to the experimental group, and saline to the control group (1 to 3 mL) by injection of 1-mL every 5 min. The results showed a significant increase in MIPS as a function of the injection volume, but the heart rate was stable. In the experimental (ACH) group, there was a statistically significant positive correlation of the intracranial pressure and MIPS. The change of MIPS was greater in the ACH group than in the control group. This high-sensitivity system could detect a 1-mL change in blood volume. The MIPS was significantly related to the intracranial pressure. This observation suggests that the method could be valuable for detecting early warning signs in emergency medicine and critical care units.

The application of chromosome abnormality chip detection in male infertility / Aplicación de la detección de la anormalidad del cromosoma mediante biochips genéticos en la infertilidad masculina

OBJECTIVE: To discuss the application of microarray technology in the diagnosis of male infertility. METHODS: Sixteen loci, including a sex-determining region on the Y chromosome, were investigated by polymerase chain reaction (PCR) in infertile male patients. Chromosome abnormality chip with 180 000 probes was used to detect small deletion, small amplification and loss of heterozygosity. RESULTS: By PCR, nine of 103 infertile patients were found to have sequence-tagged site microdeletions. Microdeletions were not observed in control samples. The deletions detected by PCR were present in six azoospermic men (6/44, 13.6%) and in three oligoasthenoteratozoospermic (OATS) men (3/59, 5%). The overall frequency of microdeletions in infertile men was 8.7% (9/103). Chromosome abnormality chip detection 500+ detected more amplification or deletion in 51 infertile patients and the overall frequency of microdeletions in infertile men was 49.5% (51/103). CONCLUSION: Chromosome abnormality chip detection system provides a sensitive, economic and high-throughput method for detecting the deletion or amplification of genomic DNA sequences of infertile patients. Not only can it identify Yq deletions, but it can also find other chromosome abnormalities and facilitate the understanding of male infertility.

OBJETIVO: Analizar la aplicación de la tecnología de los microarreglos en el diagnóstico de la infertilidad masculina. MÉTODOS: Dieciséis loci, incluyendo una región determinante del sexo en el cromosoma Y, fueron investigados mediante reacción en cadena de la polimerasa (RCP) en pacientes hombres con problemas de infertilidad. Un biochip de la anormalidad cromosómica, con 180000 sondas, fue utilizado a fin de detectar pequeñas delecciones, pequeñas amplificaciones y pérdidas de heterocigosidad. RESULTADOS: Por medio de la RCP, se halló que nueve de 103 pacientes con infertilidad presentaban microdelecciones de sitios de secuencia marcada. Las microdelecciones no fueron observadas en las muestras de control. Las delecciones detectadas mediante RCP, estuvieron presentes en seis hombres azoospérmicos (6/44, 13.6%) y en tres hombres con oligoastenoteratozoospermia (OAT) (3/59, 5%). La frecuencia general de las microdelecciones en los hombres infértiles fue 8.7% (9/103). La detección con biochip de la anormalidad cromosómica de 500+ detectó más amplificación y delección en 51 pacientes, y la frecuencia general de microdelecciones en los hombres infértiles fue 49.5% (51/103). CONCLUSIÓN: El sistema de detección de la anormalidad del cromosoma mediante biochips genéticos representa un método sensible, económico, y de alto rendimiento, para detectar la delección o amplificación de las secuencias genómicas de ADN de pacientes infértiles. Este método puede no sólo identificar las delecciones Yq, sino también hallar otras anormalidades cromosómicas, facilitando así la comprensión de la infertilidad en los hombres.

Detection of Surgery-related Spinal Cerebrospinal Fluid Leakage Using Magnetic Resonance Myelography

Detection of cerebrospinal fluid leakage or exact localization of leakage site after spinal surgery is difficult on conventional imaging studies. We report two patients with surgery-related spinal CSF leakage detected on magnetic resonance (MR) myelography. They presented with severe headache after spinal surgeries, lumbar discectomy and excision of spinal meningioma, respectively. The sites of spinal CSF leakage in the patients were detected accurately on MR myelography, and the patients recovered from the postoperative CSF leakage after being treated with an epidural blood patch or reoperation. MR myelography may be effective in demonstrating the exact site of surgery-related spinal CSF leakage.

Wall-Eyed Monocular Internuclear Ophthalmoplegia (WEMINO) with Contraversive Ocular Tilt Reaction

Wall-eyed monocular internuclear ophthalmoplegia (WEMINO) with contraversive ocular tilt reaction has not been previously reported. A 71-year-old woman suddenly developed blurred vision. Examination revealed left internuclear ophthalmoplegia, left exotropia, right hypotropia, and rightward head tilt. Magnetic resonance imaging showed a tiny infarction at the area of the left medial longitudinal fasciculus in the upper pons. WEMINO with contraversive ocular tilt reaction may be caused by a paramedian pontine tegmental infarction that selectively involves the medial longitudinal fasciculus.