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ABSTRACTPathogens of different kinds may infect amphibians at various stages of their life and can be the immediate causes of their mortality. Salamanders are hosts to a variety of parasites, including intracellular bacteria in the order Rickettsiales. All bacteria in this order are obligate, intracellular (usually within erythrocytes) organisms that are transmitted by arthropod vectors. By examining stained blood smears of Neurergus kaiseriunder a light microscope, we encountered single or multiple round, clear to faint purple with dark purple ring inclusions within the cytoplasm which were similar to intraerythrocytic rickettsial inclusion bodies. Reported here is a case of the rickettsial-like inclusions in N. kaiseriin a captive breeding facility for the first time in Iran.

The behavior of fluorescence anisotropy and polarization in systems with multiple dyes is well known. Homo-FRET and its consequent energy migration cause the fluorescence anisotropy to decrease as the number of like fluorophores within energy transfer distance increases. This behavior is well understood when all subunits within a cluster are saturated with fluorophores. However, incomplete labeling as might occur from a mixture of endogenous and labeled monomer units, incomplete saturation of binding sites, or photobleaching produces stochastic mixtures. Models in widespread and longstanding use that describe these mixtures apply an assumption of equal fluorescence efficiency for all sites first stated by Weber and Daniel in 1966. The assumption states that fluorophores have the same brightness when free in solution as they do in close proximity to each other in a cluster. The assumption simplifies descriptions of anisotropy trends as the fractional labeling of the cluster changes. However, fluorophores in close proximity often exhibit nonadditivity due to such things as self-quenching behavior or exciplex formation. Therefore, the anisotropy of stochastic mixtures of fluorophore clusters of a particular size will depend on the behavior of those fluorophores in clusters. We present analytical expressions for fractionally labeled clusters exhibiting a range of behaviors, and experimental results from two systems: an assembled tetrameric cluster of fluorescent proteins and stochastically labeled bovine serum albumin containing up to 24 fluorophores. The experimental results indicate that clustered species do not follow the assumption of equal fluorescence efficiency in the systems studied with clustered fluorophores showing reduced fluorescence intensity. Application of the assumption of equal fluorescence efficiency will underpredict anisotropy and consequently underestimate cluster size in these two cases. The theoretical results indicate that careful selection of the fractional labeling in strongly quenched systems will enhance opportunities to determine cluster sizes, making accessible larger clusters than are currently considered possible.

ObjectivesWe sought to evaluate the regional longitudinal strain/strain rate profi les in the right atrial wall to quantify right atrial function in systolic heart failure patients.BackgroundAccording to previous studies on the deformational properties of the left atrium, the systolic strain and strain rates represent the atrial reservoir function and the early and late diastolic strain rates show the conduit and booster functions, respectively.MethodsThirty patients with a diagnosis of heart failure (left ventricular ejection fraction ≤ 35%) scheduled for right heart catheterization were enrolled. Echocardiography was performed to obtain right atrial deformation indices just before the procedure. The control group consisted of 32 healthy adults matched for age and sex.The deformity indices obtained consisted of the right atrial peak systolic strain (RAS), right atrial peak systolic strain rate (RASSR), right atrial early diastolic strain rate (RAEDSR), and right atrial late diastolic strain rate (RALDSR).ResultsThe right atrial deformation indices were signifi cantly compromised in the heart failure patients versus the normal subjects (RAS: 68.5 ± 53.9 vs 189.3 ± 61.2, P= 0.000; RASSR: 2.9 ± 1.9 vs. 5.3 ± 1.5, P= 0.000). There was a signifi cant correlation between the RAS and RASSR and cardiac output (RAS: r = 0.5, P= 0.005; RASSR: r = 0.5, P= 0.003), and cardiac index (RAS: r = 0.6, P= 0.001; RASSR: r = 0.6, P= 0.001).ConclusionIn light of our fi ndings, we conclude that a diminished RA function, as assessed by strain imaging, plays a critical role in the pathophysiological process of heart failure patients.