First report of serotype 23B Streptococcus pneumoniae isolated from an adult patient with invasive infection in Japan.

Serotype 23B Streptococcus pneumoniae was isolated from a 67-year-old Japanese patient with meningitis. This isolate was susceptible to penicillin G, while genotyped as gPISP with a mutation in a penicillin-binding motif in PBP2b. The 23B isolate was assigned to ST11996 that is related to CC439, a dominant group among serotype 23B.

Effects of transjugular intrahepatic portosystemic shunt (TIPS) on esophageal motor function and gastroesophageal reflux.

The effects of transjugular intrahepatic portosystemic shunt (TIPS) placement on esophageal motor function and gastroesophageal reflux were investigated in patients with esophageal varices. In six men with esophageal varices, esophageal manometry and upper gastrointestinal endoscopy were performed before and 15-20 days after TIPS placement. Intraesophageal pH monitoring was performed in the four patients with severe esophageal varices (defined as the largest sized varices) following TIPS placement. Findings were compared with those in six healthy men (controls) who underwent esophageal manometry and intraesophageal pH monitoring. The esophageal varices resolved or were reduced after TIPS placement. Resting lower esophageal sphincter (LES) pressures were similar in the study group before and after TIPS placement and in the control subjects. The incidence and progression of esophageal contractions were similar in the study group before and after TIPS placement and in the control subjects. At 3 cm above the LES, the amplitude of esophageal contraction after TIPS placement was significantly higher than that before TIPS placement. At 3 and 8 cm above the LES, the amplitude of esophageal contraction in the control subjects was significantly higher than that in the study group before and after TIPS placement. Esophageal acid exposure time after TIPS placement was similar to that in the controls. TIPS placement is a useful treatment that improves esophageal motor function without the occurrence of pathologic gastroesophageal reflux.

Estimation of joint fluid volume in the knee joint of rabbits by measuring the endogenous calcium concentration.

OBJECTIVES: The purpose of this study was to develop a new, simple, and more efficient method for estimating joint fluid volume in the knee of experimental animals by measuring endogenous calcium concentration, which is maintained rigidly at a constant level in the body fluid. METHODS: Calcium concentrations in the plasma and joint cavity lavage were colorimetrically measured in normal and papain-induced arthritic rabbits. The joint fluid volume was estimated by dividing the total calcium concentration in the joint cavity lavage (microg/joint) by calcium concentration in the plasma (microg/ml). To confirm the relevancy of this method, radioactivity in the plasma and joint cavity lavage was determined after intravenously injecting 3H2O. The correlation between the joint fluid volumes obtained from the two different methods was examined to evaluate the validity of the method involving measurement of the calcium concentration. Results The joint fluid volumes of normal rabbits were estimated at 401 micro/joint and that in the arthritic rabbits at 680 microl/joint by measuring calcium concentration, respectively. These values were not significantly different from those estimated by radioactivity in the plasma and joint cavity lavage (normal: 425 microl/joint, arthritis: 761 microl/joint). A statistically significant correlation was observed between the values obtained from the two methods (r = 0.985). This method is considered useful for the evaluation of therapeutic medicine for arthritis or for hydrarthrosis research using experimental animal models.

Chemonucleolytic effects of chondroitinase ABC on normal rabbit intervertebral discs. Course of action up to 10 days postinjection and minimum effective dose.

STUDY DESIGN: This study demonstrated the chemonucleolytic effects of chondroitinase ABC and its histologic and biochemical background. OBJECTIVES: To determine the course of chondroitinase ABC action on normal rabbit discs, and to find its minimum effective dosage. SUMMARY OF BACKGROUND DATA: No previous study has assessed the chemonucleolytic action of chondroitinase ABC in a time- and dose-dependent manner. This study also investigated the biochemical causes of radiologic and histologic changes in the discs. METHODS: Rabbits were injected with 4 U of pharmaceutical-grade chondroitinase ABC intradiscally. They were radiologically and histologically observed, and biochemical analyses of the discs were conducted on days 1, 3, 5, 7, and 10 postinjection in the time course study. Different doses of chondroitinase ABC were injected, and radiologic observations and water content of the discs were measured in the dose-finding study. RESULTS: The time course study revealed that the chondroitin sulfate content of discs significantly decreased from day 1 postinjection until the end of the experimental period. The weight and water content of the nucleus pulposus decreased on day 3, and disc space narrowing was observed from the day after injection. The dose-finding study showed that a dose of 0.0002 U/disc still induced disc space narrowing and a decrease in water content. CONCLUSIONS: Chondroitinase ABC is estimated to have a chemonucleolytic effect at least by day 3 postinjection at a dose level of 0.0002 U/disc or higher in rabbits.

[An experience of transjugular intrahepatic portosystemic shunt in the treatment of gastroesophageal varices].

Transjugular intrahepatic portosystemic shunt (TIPS) using an 8-mm Gianturco-Rösch Z stent was performed in 10 patients with liver cirrhosis admitted due to ruptured gastroesophageal varices. The treatment was successful in 9 patients, and the portal pressure decreased form 25 mmHg to 17 mmHg immediately after TIPS and to 15 mmHg 2 weeks after TIPS. The patency of the shunt was maintained adequately in the patients examined 3 months after TIPS. Endoscopy 1 month after TIPS showed improvements in the gastroesophageal varices in all patients. Hemobilia and intraperitoneal bleeding were observed in 1 patient each during procedure. Transient jaundice was observed in 2 and increase in the blood ammonia level were noted in 3 (one of whom had hepatic encephalopathy) postoperatively. All these complications could be treated easily. TIPS which brings about an immediate marked reduction in the portal pressure appears to be promising as a new treatment for portal hypertension.

Multipulse operation and optical detection of nuclear spin coherence in a GaAs/AlGaAs quantum well.

We demonstrate manipulation of nuclear spin coherence in a GaAs/AlGaAs quantum well by optically detected nuclear magnetic resonance (NMR). A phase shift of the Larmor precession of photoexcited electron spins is detected to read out the hyperfine-coupled nuclear spin polarization. Multipulse NMR sequences are generated to control the population and examine the phase coherence in quadrupolar-split spin-3/2 75As nuclei. The phase coherence among the multilevel nuclear spin states is addressed by application of pulse sequences that are used in quantum gate operations.

Optical pump-probe measurements of local nuclear spin coherence in semiconductor quantum wells.

We demonstrate local manipulation and detection of nuclear spin coherence in semiconductor quantum wells by an optical pump-probe technique combined with pulse rf NMR. The Larmor precession of photoexcited electron spins is monitored by time-resolved Kerr rotation (TRKR) as a measure of nuclear magnetic field. Under the irradiation of resonant pulsed rf magnetic fields, Rabi oscillations of nuclear spins are traced by TRKR signals. The intrinsic coherence time evaluated by a spin-echo technique reveals the dependence on the orientation of the magnetic field with respect to the crystalline axis as expected by the nearest neighbor dipole-dipole interaction.

Gate control of dynamic nuclear polarization in GaAs quantum wells.

Gate control of dynamic nuclear polarization under optical orientation is demonstrated in a Schottky-gated n-GaAs/AlGaAs (110) quantum well by time-resolved Kerr rotation measurements. Spin relaxation of electrons due to mechanisms other than the hyperfine interaction is effectively suppressed as the donor induced background electron density is reduced from metallic to insulating regimes. Subsequent accumulation of photoexcited electron spins dramatically enhances dynamic nuclear polarization at low magnetic field, allowing us to tune nuclear spin polarization by external gate voltages.