Mechanism of hepatic parenchyma-specific contrast of microbubble-based contrast agent for ultrasonography: microscopic studies in rat liver

OBJECTIVE: The objective of this study was to elucidate the mechanism of hepatic parenchyma-specific contrast of Sonazoid (microbubble contrast agent) using microscopic techniques. MATERIALS AND METHODS: Sonazoid was intravenously injected into rats to investigate the microbubble dynamics and distribution within hepatic microcirculation in exteriorized liver using intravital microscopy and to observe dose dependency of ultrasound hepatic contrast effect. In vitro and in vivo uptake of microbubbles by Kupffer cells was examined using confocal laser scanning microscopy. RESULTS: Intravital observation demonstrated freely flowing microbubbles in the sinusoid and some microbubbles co-localized with Kupffer cells. The microbubbles internalized in Kupffer cells were identified with reflected light by confocal laser scanning microscopy. The percentage of Kupffer cells taking up microbubbles was about 1% at clinical dose at which the homogeneous hepatic contrast was observed. CONCLUSIONS: The hepatic parenchyma-specific contrast by Sonazoid is due to distribution of the microbubbles in Kupffer cells.     

Regeneration of the hamstring tendons after harvesting for arthroscopic anterior cruciate ligament reconstruction: a histological study in 11 patients

The purpose of our study is to evaluate whether the hamstring tendons can regrow after harvesting for anterior cruciate ligament (ACL) reconstruction and whether the regenerate tissue can be histologically characterized as tendinous. Eleven of the patients (eight female and three male; mean age, 23 years; range 17–37 years) consented to participate in this study. One year after the ACL reconstruction, surgical biopsy was done. Regeneration of the tendon was detected macroscopically in 9 of the 11 patients. Histologically and immunohistochemically, the regenerated tendons closely resembled normal ones. The results of this study show the hamstring tendons can regenerate after harvesting for the ACL reconstruction.     

Treadmill running combined with microdialysis can evaluate motor deficit and improvement following dopaminergic grafts in 6-OHDA lesioned rats

To evaluate the physiological role of striatal dopamine (DA) during exercise and the mechanism of functional recovery mediated by grafted DAergic neurons, the locomotor ability (treadmill running) and DA turnover were investigated using treadmill running combined with in vivo microdialysis in the intact control rats, 6-hydroxydopamine (6-OHDA) lesioned rats (hemi-parkinsonian model rats) and DAergic cell grafted rats. The 3 groups of rats were trained to run on a straight treadmill at a speed of 1,800 cm/min for 20 min every day for 7 consecutive days. If the rats could not follow the speed they got electrostimulation (ES) from the grid behind the treadmill belt. The numbers of ES rats received during treadmill running were counted to quantify the locomotor ability. Control rats could keep up with the treadmill easily (0-1 ES/10 min), whereas lesioned rats could not follow the speed (80-100 ES/10 min). Most of the grafted rats received only a few ES, but a few received over 100 ES/10 min. Extracellular DA and its metabolites, dihydroxyphenyl acetic acid (DOPAC) and homovanillic acid (HVA), were measured by in vivo microdialysis and high-performance liquid chromatography (HPLC) during and after treadmill running. In control rats the basal levels of DA, DOPAC and HVA were 2.3 fmol/μl, 1,109.8 fmol/μl and 612.2 fmol/μl, respectively. They increased up to 130%, 140% and 160% by running. In 6-OHDA lesioned rats basal values of DA, DOPAC and HVA were less than 10% of controls. We did not perform microdialysis in these rats since they got too much ES during running. In grafted rats that showed good recovery in locomotor ability, DA returned to almost control level (1.9 fmol/μl), but those of DOPAC (127.8 fmol/μl) and HVA (100.2 fmol/μl) were still low. DA, DOPAC and HVA increased up to 130%, 130% and 150% by running in a similar pattern as in intact rats. These results suggest that grafted neurons can release and metabolize DA in the host striatum both tonically and phasically in relation with internal and external stimuli and also suggest that treadmill running ability is a good indicator of DA turnover in the striatum. Thus, the treadmill running test with microdialysis is useful for quantitative evaluation of motor function in grafted animals.     

Identifying the primary epileptogenic hemisphere from electroencephalographic (EEG) and magnetoencephalographic dipole lateralizations in children with intractable epilepsy

We used electroencephalographic (EEG) and magnetoencephalographic dipole lateralizations to identify the primary epileptogenic hemisphere in 41 children with intractable localization-related epilepsy. We compared EEG and magnetoencephalographic dipole lateralizations, EEG ictal onsets, and magnetic resonance images (MRIs). Concordant lateralization of EEG and magnetoencephalographic dipoles (> 50% of each lateralizing to the same hemisphere) occurred in 34 patients, with EEG ictal onsets in the same hemisphere in 23 (68%) and concordant MRI lesions in 23 (68%). Focal resection in 16 of 20 patients resulted in a good surgical outcome. Of the seven children with nonconcordant magnetoencephalographic and EEG lateralizations, one (14%) had EEG ictal onset and one (14%) had MRI lesions that lateralized; none had surgery. The relationship between lateralized EEG and magnetoencephalographic dipoles forecasts surgical candidacy. Concordant lateralizations predict good seizure control after surgery by identifying the primary epileptogenic hemisphere. Discordant lateralizations signify an undetermined epileptogenic hemisphere and contraindicate surgery without further testing.     

Changes in Brain Thyrotropin-Releasing Hormone (TRH) of El Mice

The present study showed that DN-1417 had a dose-dependent anticonvulsant activity on El mouse seizure. This finding is consistent with other reports using the kindling model of epilepsy. Since both the El mouse and kindling preparations have been regarded as complex partial seizure with secondary generalization, endogenous brain TRH, as well as exogenous TRH, may act as an anticonvulsant substance to such a seizure type of epilepsy. Moreover, this study showed IR-TRH of the El mouse changed significantly in the striatum or hippocampus genetically or postictally without a change in the TRH receptor binding. A transient decrease in hippocampal IR-TRH after convulsion shown in this study may suggest an increased release of TRH during and after the seizure.
Further studies are required to clarify the relationship between a change in the brain TRH system and seizure susceptibility in the El mouse.     

Long-term follow-up of patients with hepatitis B e antigen negative chronic hepatitis B

Background and Aim: After hepatitis B virus (HBV) e antigen (HBeAg) seroconversion, HBV‐DNA continues to replicate, and HBeAg‐negative patients still face the risk of liver disease progression. We investigated the predictive factors for alanine aminotransferase (ALT) elevation, antiviral drug use, and hepatocellular carcinoma (HCC) occurrence in HBeAg‐negative patients. Methods: Age, sex, ALT, platelet counts, HBV‐DNA levels, genotype, antidiabetic drug use, body mass index, smoking, and alcohol consumption were analyzed for a total of 244 HBV carriers who were HBeAg‐negative. Results: Of 244 HBeAg‐negative patients, 158 (64.8%) showed normal ALT levels at baseline. Multivariate Cox hazard regression analysis identified high HBV‐DNA levels and high ALT at baseline as independent risk factors for ALT elevation in the patients with normal ALT at baseline. The threshold ALT and HBV‐DNA levels were determined to be 31 IU/L and 5.3 logcopies/mL, respectively. Seventeen (7.0%) patients used antiviral drugs. Multivariate Cox hazard regression analysis identified high HBV‐DNA levels (threshold, 5.7 log copies/mL), the use of antidiabetic drugs, and daily alcohol consumption at baseline as an independent risk factor for the use of antiviral drugs in HBeAg‐negative patients. In 10 patients (4.1%), HCC was detected, and a low platelet count (threshold, 10.0 × 10⁴/mm³) was associated with the occurrence of HCC. Conclusion: This study identified predictors of future active liver disease in HBeAg‐negative patients, i.e. ALT elevation, unavoidable use of antiviral drugs, and occurrence of HCC.     

High white blood cell count and low estimated glomerular filtration rate are independently associated with serum level of monocyte chemoattractant protein-1 in a general population

Background

Monocyte chemoattractant protein‐1 (MCP‐1) plays a role in cardiovascular disease (CVD) and renal injury. Recent clinical studies have suggested that circulating levels of MCP‐1 could be a biomarker of atherosclerosis and future cardiovascular events in humans. Because chronic kidney disease (CKD) is one of the risk factors of CVD, it is conceivable that elevated MCP‐1 levels may link the increased risk of CVD in CKD patients. However, as far as we know, in addition to well‐known traditional risk factors for atherosclerosis, whether renal dysfunction could be independently associated with the elevation of MCP‐1 levels in a general population remains unknown. Therefore, we examined here which anthropometric and metabolic variables, including renal function, could be independent correlates of circulating levels of MCP‐1 in a general population.

Hypothesis

We hypothesized that renal function was one of the independent correlates of serum MCP‐1 levels.

Methods

A total of 860 Japanese residents (318 males and 542 females, mean age 65.4 ± 9.8 years) in a small fishing community underwent a complete history and physical examination with determination of blood chemistries, including serum levels of MCP‐1.

Results

Mean MCP‐1 levels were 281.4 pg/mL. Multiple stepwise regression analyses revealed that male sex (P < 0.0001), age (P = 0.03), estimated glomerular filtration rate (eGFR) (P < 0.0001, inversely), and white blood cell count (P = 0.037) were independently associated with MCP‐1 levels.

Conclusions

The present study demonstrated for the first time that other than white blood cell count, eGFR was an independent correlate of serum levels of MCP‐1 in a Japanese general population. Elevated MCP‐1 levels may partly explain the increased risk of CVD in CKD patients. © 2011 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.