Bone Tissue Engineering in Rat Calvarial Defects Using Induced Bone-like Tissue by rhBMPs from Immature Muscular Tissues In Vitro

This study aimed to induce bone-like tissue from immature muscular tissue (IMT) in vitro using commercially available recombinant human bone morphogenetic protein (rhBMP)-2, rhBMP-4, and rhBMP-7, and then implanting this tissue into a calvarial defect in rats to assess healing. IMTs were extracted from 20-day-old Sprague-Dawley (SD) fetal rats, placed on expanded polytetrafluoroethylene (ePTFE) with 10 ng/μL each of rhBMP-2, BMP-4, and BMP-7, and cultured for two weeks. The specimens were implanted into calvarial defects in 3-week-old SD rats for up to three weeks. Relatively strong radiopacity was observed on micro-CT two weeks after culture, and bone-like tissue, comprising osteoblastic cells and osteoids, was partially observed by H&E staining. Calcium, phosphorus, and oxygen were detected in the extracellular matrix using an electron probe micro analyzer, and X-ray diffraction patterns and Fourier transform infrared spectroscopy spectra of the specimen were found to have typical apatite crystal peaks and spectra, respectively. Furthermore, partial strong radiopacity and ossification were confirmed one week after implantation, and a dominant novel bone was observed after two weeks in the defect site. Thus, rhBMP-2, BMP-4, and BMP-7 differentiated IMT into bone-like tissue in vitro, and this induced bone-like tissue has ossification potential and promotes the healing of calvarial defects. Our results suggest that IMT is an effective tissue source for bone tissue engineering.     

Stacked Thiazole Orange Dyes in DNA Capable of Switching Emissive Behavior in Response to Structural Transitions

Functional nucleic acids with the capability of generating fluorescence in response to hybridization events, microenvironment or structural changes are valuable as structural probes and chemical sensors. We now demonstrate the enzyme-assisted preparation of nucleic acids possessing multiple thiazole orange (TO) dyes and their fluorescent behavior, that show a spectral change from the typical monomer emission to the excimer-type red-shifted emission. We found that the fluorescent response and emission wavelength of the TO dyes were dependent on both the state of the DNA structure (single- or double-stranded DNA) and the arrangement of the TO dyes. We showed that the fluorescent behavior of the TO dyes can be applied for the detection of RNA molecules, suggesting that our approach for preparing the fluorescent nucleic acids functionalized with multiple TO dyes could be useful to design a fluorescence bioimaging and detection technique of biomolecules.     

Studies on the antiviral mechanisms of protein kinase inhibitors K-252a and KT5926 against the replication of vesicular stomatitis virus

INTRODUCTION: We investigated the accuracy of MRI of the prostate with an endorectal surface coil in determing penetration of the prostatic capsule and invasion of seminal vescicles in prostate carcinoma. MATERIAL AND METHODS: Endorectal coil MRI (1 Tesla) was performed in 300 patients with biopsy-proved cancer. The PSA levels were always calculated and all the patients were examined with transrectal ultrasound. The imaging protocol included Turbo Spin Echo T2-weigthed (3900/150 TR/TE) axial and coronal images and T1-weigthed (650/15 TR/TE) axial images, 4 mm thick interleaved sections with .4 mm intersection gap, FOV 180 mm, 256 x 256 matrix (reconstruction 512). Seventy-five patients underwent radical prostatectomy and MR images were compared with pathologic findings of capsular penetration and invasion of seminal vescicles. The MR signs specific for capsular penetration were: deformation (irregularity) of capsular profile, capsular retraction with irregular margins, capsular interruption, obliteration of periprostatic adipose tissue, asymmetry of neurovascular bundles. RESULTS: MRI correctly depicted 37 of 45 pathologic stage T2 lesions and correctly depicted macroscopic capsular penetration (T3) in 18 of 23 cases. Microscopic capsular penetration was overestimated in all 7 cases. Sensitivity, specificity, accuracy, for microscopic and macroscopic capsular penetration were 60, 82, 73% respectively. Sensitivity, specificity, accuracy for macroscopic capsular penetration were 78, 82, 80% respectively. Sensitivity, specificity, accuracy for depiction of seminal vesicle involvment were 80, 100, 93%, respectively. The most reliable signs of capsular penetration were capsular interruption and invasion of periprostatic adipose tissue, while asymmetry of the neurovascular bundle was not seen. CONCLUSIONS: MRI provides accurate preoperative local staging. The two main limitations of MRI were the high rate of microscopic capsular penetration and the difficulty in detecting capsular penetration of tumor when the lesions are in the prostate apex. Prostate enlargement also made diagnosis more difficult.     

Transcranial assessment of maternal cerebral blood flow velocity in patients with pre-eclampsia

BACKGROUND: To clarify the cerebral hemodynamics in pre-eclamptic pregnant women, we investigated the blood flow velocity of the cerebral arteries. METHODS: The mean blood flow velocity and pulsatility index (PI) of the middle cerebral artery (MCA) and internal carotid artery (ICA) in normal pregnant women (n = 35) and pre-eclamptic patients (n = 18) were examined transcranially using pulsed-wave Doppler technique with a 2 MHz probe. In two pre-eclamptic women with post-partum visual disturbance, we examined the mean blood flow velocity and PI of the MCA and ICA every day. RESULTS: The mean blood flow velocity of the MCA in the pre-eclamptic patients (89.7 +/- 20.5 cm/s) was significantly higher than that in the normal pregnant women (53.6 +/- 16.9 cm/s) (p < 0.05). PI of the MCA in the former group (0.67 +/- 0.13) was significantly lower than that in the latter (0.78 +/- 0.02) (p < 0.05). There was no significant difference between these two groups in these variables of the ICA. In the two patients with visual disturbance, the mean blood flow velocity of the MCA was increased before the onset of visual disturbance and decreased gradually following the disappearance of this symptom. In these patients, spasm of the MCA was confirmed by magnetic resonance angiography. CONCLUSIONS: In pre-eclamptic patients, we found increased MCA mean velocity before the onset of visual disturbance. Transcranial Doppler may be useful for the evaluation of cerebral hemodynamics and the prediction of eclampsia.     

Diffusion of low molecular weight substances into a fiber with skin-core structure—rigorous solution of the diffusion in a coaxial cylinder of multiple components

The diffusion equation of low molecular weight substances (penetrant) into a coaxial cylinder of multiple components (m) was formulated in general and solved rigorously. As the simplest but a practical case of m = 2, which corresponds to the diffusion of penetrant into fibrous material with skin and core structure, the diffusion of penetrant was analyzed in detail. That is, changes in the penetrant concentration distribution within the coaxial dual cylinder of skin and core components and the total amount of penetrant sorbed within the cylinder both with time after exposing the cylinder to atmosphere of fixed penetrant concentration of C_out were calculated with variation of the diffusion coefficient ratio (D₁/D₂) and the radius ratio (R₂/R₁), where D₁ and D₂ are the diffusion coefficients of penetrant in the core and the skin, and R₂ and R₁ are the radii of the fibrous material and the core, respectively. Keeping (R₂/R₁) at a constant value of 1.2 but varying (D₁/D₂) from 10⁴ to 10^?2, the penetrant concentration distribution was calculated and found to be much different particularly within the core between (D₁/D₂) > 1 and (D₁/D₂) < 1. The sorption curves were also found to deviate in their respective ways from that of Fickian curve of a homogeneous cylinder with (D₁/D₂) = 1 except at initial stage of sorption. Further, by keeping (D₁/D₂) constant but varying (R₂/R₁) from 1.1 to 1.5, the effects of relative skin thickness upon the sorption curve were studied.     

Characterization of the L-malate permease gene (maeP) of Streptococcus bovis ATCC 15352

A gene which was shown to be cotranscribed with the NAD+-dependent malic enzyme gene (maeE) of Streptococcus bovis ATCC 15352 was revealed to encode L-malate-specific permease (MaeP), which showed high activity at low pHs (pH 5.1 to 5.9). MaeP was strongly inhibited by the ionophores nigericin and valinomycin.     

Effect of argatroban on microthrombi formation and brain damage in the rat middle cerebral artery thrombosis model

BACKGROUND: The role of the kidney in the development of essential hypertension is subject of debate. METHODS: We compared the renin, kallikrein and prostaglandin renal systems in two groups of normotensive boys, aged 7-16 years, with different degrees of risk for future hypertension: 27 had parents with essential hypertension and 12 had normotensive parents. Supine, standing and post-exercise plasma renin activity as well as levels of urinary kallikrein and prostaglandin E2 before and after exercise were measured. RESULTS: The ratio of post-exercise plasma renin activity (ng/ml/h) to 24 h urinary sodium excretion (mEq/kg/day) was lower in children with hypertensive parents (mean +/- SEM 1.86 +/- 0.24 compared with 3.62 +/- 0.94, P = 0.02). The boys with hypertensive parents had a lower ratio of urinary kallikrein to creatinine before (0.70 +/- 0.13 compared with 1.54 +/- 0.36, P = 0.01) and after exercise (0.80 +/- 0.13 compared with 1.35 +/- 0.23, P = 0.03). The ratio of urinary prostaglandin E2 to creatinine levels did not differ between the groups before or after exercise. CONCLUSION: The plasma renin activity response to exercise and urinary kallikrein excretion were decreased in boys at increased risk of future essential hypertension. These early abnormalities in the renin and kallikrein renal systems may be associated with the development of essential hypertension.