Caffeine actions on currents induced by calcium-overload in Purkinje fibers

The ionic events underlying the changes induced by caffeine in calcium-overloaded Purkinje fibers were studied by means of a voltage-clamp technique. The following results were obtained. In fibers exposed to strophanthidin (5 X 10(-7) M), a depolarizing clamp of suitable magnitude or duration is followed by an oscillatory current (Ios) often superimposed on a decaying inward tail current (the "tail current"). Caffeine (9 mM) abolishes Ios and increases the tail current. Caffeine has similar actions when calcium overload is induced by increasing [Ca]0 or decreasing [Na]0. The magnitude of the tail current is reduced by decreasing [Ca]0. The tail current appears with repolarizations to -40 mV or more negative values as Ios appears in the absence of caffeine. As with Ios the tail current can be triggered twice (during and after a test clamp of suitable characteristics), becomes more inward with repeated clamps and becomes larger with larger or longer conditioning clamps. During the recovery from caffeine exposure, the tail current decreases gradually as Ios returns progressively. It is concluded that both Ios and tail current are caused by calcium overload but are affected in opposite direction by caffeine, apparently because caffeine decreases the calcium overload in the sarcoplasmic reticulum (abolition of Ios) and increases the calcium to be extruded from the sarcoplasm (increase in the tail current).     

睫状神经营养因子对应激大鼠体质量的影响及其机制探讨

①目的　探讨睫状神经营养因子 (CNTF)对躯体性和心理性应激大鼠体质量的影响及其与下丘脑促肾上腺皮质素释放激素 (CRH)含量的关系。②方法　建立应激大鼠动物模型 ,应用鼠脑立体定向方法 ,在应激前给予大鼠双侧海马微量注射CNTF ,称量大鼠应激前后的体质量变化 ,并用放射免疫分析法测定大鼠下丘脑CRH含量的变化。③结果　在应激前及应激期间给予双侧海马微量注射CNTF ,可以有效改善应激引起的大鼠体质量的下降 (t=2 .16 3.86 ,P <0 .0 5 ,0 .0 1) ,改善应激引起的下丘脑CRH含量的升高 (t=3.0 5 4.0 3,P <0 .0 1)。④结论　CNTF可以改善应激对大鼠生长的损害 ,其机制可能与CNTF降低应激大鼠下丘脑CRH的含量有关。     

Longer Term Outcomes Following High Tibial Osteotomy for Osteoarthritis: A Prospective,Multi-Centre Observational Study Comparing Tomofix and OPTY-LINE Devices

PurposeAssessing surgical accuracy and patient-recorded outcome measures for patients fitted with either the OPTY-LINE intramedullary realignment system or the Tomofix plate for medial opening wedge high tibial osteotomy (HTO).Patients and methodsTwo matched case series of patients with symptomatic medial compartment osteoarthritis without other significant knee pathology. One group comprised of 19 patients receiving the Tomofix plate, whereas another comprised of 12 patients receiving the OPTY-LINE intramedullary nail. Patella-centred long leg alignment radiographs were assessed to calculate surgical accuracy in all cases. Patients completed knee injury osteoarthritis outcome scores (KOOS) and osteotomy surgery patient satisfaction questionnaires pre-operatively and at 24 months post-surgery.ResultsAbsolute surgical accuracy at 2 years post-surgery was a mean 4.2 [standard deviation 3.7] for OPTY-LINE versus 9.2 [SD 7.8] for Tomofix (p = 0.11, Mann–Whitney U test). On average, patients in either the OPTY-LINE or Tomofix cohort reported at least a minimal perceptible clinical improvement—minimum average improvement of 15—for all five KOOS themes. No significant difference in change of KOOS scores over time or patient satisfaction levels were observed between the two cohorts.ConclusionThe OPTY-LINE device for HTO performs to a similar level as the Tomofix device. Surgical accuracy data are promising for OPTY-LINE, but does not seem to readily translate into difference in patient-reported outcomes compared to Tomofix. Even longer follow-up periods, to measure survival rates, and true randomised trials on larger samples can elucidate if there is a benefit for using one device over the other.     

Rapid detection of resistance in Mycobacterium tuberculosis: a review discussing molecular approaches

The last few years have seen the development of several molecular designs to search for mutations encoding resistance to antituberculous drugs in Mycobacterium tuberculosis . Most of these are highly efficient for RIF-r detection and are well adapted to search for the most relevant INH-R mutations. In this review, these new molecular approaches are explained and are presented according to the molecular strategies on which they are based. In this sense, techniques based on DNA-sequencing, electrophoresis and hybridization are reviewed and the newer designs based on real-time PCR and microarrays are also included. Molecular methods are sure to transform standard approaches to the issue of resistance in the mycobacteriology laboratory. This will allow laboratories to speed up the performance of resistance assays and provide access to essential information for highly refined detection, follow-up and management of antibiotic resistance in M. tuberculosis .