Probiotic related Lactobacillus rhamnosus endocarditis in a patient with liver cirrhosis.

Lactobacilli are commensals in the gastrointestinal and genitourinary tracts and considered as having low pathogenicity. Many species including Lactobacillus rhamnosus are now available as probiotics and their use has widely increased in recent years. Lactobacilli have the propensity to cause invasive infections such as bacteraemia and endocarditis predominantly in an immunocompromised host. We report a case of fatal Lactobacillus rhamnosus endocarditis involving a young patient with a history of complicated cirrhosis and prior Clostridium difficile colitis; and present a literature review and discussion of the possible association of systemic infection with 'probiotic' formulations containing lactobacilli.

Ellipsometric Scatterometry for the Metrology of Sub-0.1- num-Linewidth Structures.

We describe a modification to our existing scatterometry technique for extracting the relative phase and amplitude of the electric field diffracted from a grating. This modification represents a novel combination of aspects of ellipsometry and scatterometry to provide improved sensitivity to small variations in the linewidth of subwavelength gratings compared with conventional scatterometer measurements. We present preliminary theoretical and experimental results that illustrate the possibility of the ellipsometric scatterometry technique providing a metrology tool for characterizing sub-0.1-mum-linewidth.

Linewidth measurement of gratings on photomasks: a simple technique.

A novel laser scatterometer linewidth measurement tool has been developed for critical dimension metrology of photomasks. Calculation of the linewidth is based on a rigorous theoretical model, thus eliminating the need for calibrations. In addition the effect of the glass substrate on which the photomask grating is placed is explicitly taken into account. The experimental arrangement consists of a chrome photomask diffraction grating that is illuminated with a laser. A rigorous theoretical model is used to provide a lookup table that gives the power in the transmitted zero-order beam as a function of the linewidth for a fixed pitch of the grating. The predicted linewidth values are compared with those that are obtained by using commercial optical linewidth measurement systems, and excellent agreement is obtained.

Respiratory sinus arrhythmia in dogs. Effects of phasic afferents and chemostimulation.

We examined the hypothesis that respiratory sinus arrhythmia (RSA) is primarily a central phenomenon and thus that RSA is directly correlated with respiratory controller output. RSA was measured in nine anesthetized dogs, first during spontaneous breathing (SB) and then during constant flow ventilation (CFV), a technique whereby phasic chest wall movements and thoracic pressure swings are eliminated. Measurements of the heart rate and of the moving time averaged (MTA) phrenic neurogram during these two ventilatory modes were made during progressive hypercapnia and progressive hypoxia. RSA divided by the MTA phrenic amplitude (RSAa) showed a power-law relationship with both arterial carbon dioxide partial pressure (PaCO2) and oxygen saturation (SaO2), but with different exponents for different conditions. However, the power-law relation between RSAa and respiratory frequency had an exponent indistinguishable from -2 whether hypoxia or hypercapnia was the stimulus for increased respiratory drive, and during both CFV and spontaneous breathing (-1.9 +/- 0.4, hypoxia, SB; -1.8 +/- 0.7, hypoxia, CFV; -2.1 +/- 0.8, hypercapnia, SB; -1.9 +/- 0.7, hypercapnia, CFV). We conclude that respiratory sinus arrhythmia is centrally mediated and directly related to respiratory drive, and that changes in blood gases and phasic afferent signals affect RSA primarily by influencing respiratory drive.

Phrenic neural output during hypoxia in dogs: constant-flow ventilation vs. spontaneous breathing.

We studied the effects of removing cyclic pulmonary afferent neural information on respiratory pattern generation in anesthetized dogs. Phrenic neural output during spontaneous breathing (SB) was compared with that occurring during constant-flow ventilation (CFV) at several levels of eucapnic hypoxemia. Hypoxia caused an increase in both the frequency and the amplitude of the moving time average (MTA) phrenic neurogram during both SB and CFV. The change in frequency as arterial saturation was reduced from 90 to 60% during SB was significantly higher than that during CFV [SB, 32.3 +/- 10.9 (SD) breaths/min; CFV, 10.3 +/- 5.8 breaths/min; P = 0.001]. By contrast, the increase in the amplitude of the MTA phrenic neurogram was smaller (SB, 0.62 +/- 0.68 units; CFV, 1.35 +/- 0.81 units; P = 0.01). The changes in frequency with hypoxia during both modes of ventilation resulted primarily from a shortening of expiratory time. Both inspiratory time and expiratory time were greater during CFV than during SB, but their change in response to hypoxia was not significantly different. We conclude that the amplitude response of the MTA phrenic neurogram to hypoxia is similar to that seen during hypercapnia; in the presence of phasic afferent feedback the MTA amplitude response is decreased and the frequency response is increased relative to the response observed in the absence of phasic afferents.