Two cases of pregnant women with ovarian endometrioma mimicking a malignant ovarian tumor

The detection of an ovarian mass during pregnancy is often a diagnostic challenge. We describe 2 cases of ovarian endometrioma during pregnancy with marked mural nodules on the cyst wall. The sonographic and MR imaging findings mimicked ovarian cancer. Surgical intervention may still be inevitable to exclude the possibility of malignancy.     

A case of glomerulopathy showing podocytic infolding in association with Sjögren’s syndrome and primary biliary cirrhosis

A 49-year-old man was admitted to our hospital with mild proteinuria. Prior to admission, he had been diagnosed as having Sjögren’s syndrome in association with primary biliary cirrhosis. Examination of a renal biopsy under light microscopy revealed diffuse and global mesangial cell proliferation and a spike and/or bubbling formation of the glomerular basement membrane (GBM), resembling membranoproliferative glomerulonephritis. In contrast, immunofluorescent studies showed marked immunoglobulin and complement depositions in the mesangial areas; however, only faint granular IgG and IgA deposition was observed along the GBM. Interestingly, electron microscopy revealed that a microtubular structure, derived from podocytes, was present in the GBM. We present a case of glomerulopathy showing podocytic infolding in association with Sjögren’s syndrome and primary biliary cirrhosis.     

Microheterogeneity of regional myocardial blood flows in low-perfused rat hearts evaluated by double-tracer digital radiography.

Using (3)H- and (125)I-labeled desmethylimipramine (DMI) for regional flow tracers, we established a two-time measurement method for the spatial pattern of myocardial perfusion in cross-circulated rat hearts. Myocardial extractions and retentions of these tracers were confirmed to be satisfactory; however, the latter were less than 90% after 3 min at a perfusion rate of 2.9 ml/min/g, limiting the present application to a short-time perfusion measurement. Distributions of myocardial depositions were separated by subtraction digital radiography with 400-microm pixel resolution. Its feasibility was examined by regression analysis between local deposition densities of (3)H- and (125)I-DMI injected simultaneously. The slope, y-intercept, and correlation coefficient (r) of the regression line were 0.98+/-0.04, 0.02+/-0.04, and 0.95+/-0.03, respectively, indicating the validity of the present image subtraction technique. The spatial pattern of myocardial perfusion in response to flow reduction was evaluated by the injections of (3)H- and (125)I-DMI, respectively, before and after a nearly 70% flow reduction. A significant correlation between normalized density distributions of these tracers was found in both subepicardium (r=0.77+/-0.12) and subendocardium (r=0.73+/-0.20), indicating the stable pattern of myocardial perfusion. However, the coefficient of variation of tracer densities showed a decrease of subendocardial flow heterogeneity from 35+/-15% to 31+/-16%. Thus, flow differences between originally high- and low-flow regions in subendocardium were reduced on a relative basis during low perfusion.     

A possible role of midbrain dopamine neurons in short- and long-term adaptation of saccades to position-reward mapping

Dopamine (DA) neurons respond to sensory stimuli that predict reward. To understand how DA neurons acquire such ability, we trained monkeys on a one-direction-rewarded version of memory-guided saccade task (1DR) only when we recorded from single DA neurons. In 1DR, position-reward mapping was changed across blocks of trials. In the early stage of training of 1DR, DA neurons responded to reward delivery; in the later stages, they responded predominantly to the visual cue that predicted reward or no reward (reward predictor) differentially. We found that such a shift of activity from reward to reward predictor also occurred within a block of trials after position-reward mapping was altered. A main effect of long-term training was to accelerate the within-block reward-to-predictor shift of DA neuronal responses. The within-block shift appeared first in the intermediate stage, but was slow, and DA neurons often responded to the cue that indicated reward in the preceding block. In the advanced stage, the reward-to-predictor shift occurred quickly such that the DA neurons' responses to visual cues faithfully matched the current position-reward mapping. Changes in the DA neuronal responses co-varied with the reward-predictive differentiation of saccade latency both in short-term (within-block) and long-term adaptation. DA neurons' response to the fixation point also underwent long-term changes until it occurred predominantly in the first trial within a block. This might trigger a switch between the learned sets. These results suggest that midbrain DA neurons play an essential role in adapting oculomotor behavior to frequent switches in position-reward mapping.     

An optical-fiber laser Doppler velocimeter and its application to measurements of coronary blood flow velocities

In this paper we describe a laser Doppler velocimeter (LDV) with an optical fiber that measures blood flow velocities accurately in a small sample volume. The principle, optical arrangement, spatial and the temporal resolutions and accuracy for blood flow measurements are delineated, followed by a report of the results of measurements of coronary artery and vein blood flow velocities in dogs. Finally, we touch upon some recent progress made in the LDV with an optical fiber pickup.     

Three Na+/Ca2+ exchanger (NCX) variants are expressed in mouse osteoclasts and mediate calcium transport during bone resorption

The plasma membrane Na(+)/Ca(2+) exchanger (NCX) is a bidirectional transporter that mediates the exchange of Na(+) for Ca(2+) depending on the electrochemical gradients. Mammalian NCXs form a multigene family comprising NCX1, NCX2, and NCX3 isoforms. Although it has been known that NCX1 in rat osteoclasts is coupled with the Na(+)/ H(+) exchanger for regulation of intracellular Ca(2+) concentration ([Ca(2+)](i)), it is unclear what kind of NCX1 variants are expressed and whether the other two NCX isoforms are also present in mouse osteoclasts. To clarify the role of NCXs during bone resorption, we investigated the expression of NCXs, the ion transport via NCXs, and the effects of NCX inhibitors on bone-resorbing activity in mouse osteoclasts. Using RT-PCR, immunocytochemical, and Western blot methods, we detected three splice variants of NCX1 and NCX3, namely NCX1.3, NCX1.41, and NCX3.2. Of these, NCX1.41 is a newly identified splice variant. Low extracellular sodium ([Na(+)](o)) solution increases the intracellular Ca(2+) concentration via NCX transporter in fura-2-loaded osteoclasts. The [Na(+)](o)-free solution-induced [Ca(2+)](i) increase was suppressed by benzyloxyphenyl NCX inhibitors. Bidirectional NCX currents in mouse osteoclasts were recorded using the patch clamp method and could be suppressed with NCX inhibitors. NCX inhibitors also decreased the resorption pit area surrounding osteoclasts in a dose-dependent manner. Furthermore, small interference RNAs targeted against NCX1.3, NCX1.41, and NCX3.2 expressed in mouse osteoclasts suppressed osteoclastic pit formation. These results show that three NCX variants are expressed in mouse osteoclasts and play an important role for Ca(2+) transport and regulation during osteoclastic bone resorption.     

Loss of vancomycin bactericidal activity against accessory gene regulator (agr) dysfunctional Staphylococcus aureus under conditions of high bacterial density

The impact of accessory gene regulator (agr) dysfunction and high bacterial density on vancomycin killing and resistance was evaluated among 10 clinical methicillin-resistant Staphylococcus aureus bloodstream isolates using time kill experiments. Under conditions of high inocula and agr dysfunction, vancomycin activity was markedly attenuated, amplifying resistant mutants by 72 h.