High-frequency ultrasonic attenuation and backscatter coefficients of in vivo normal human dermis and subcutaneous fat.

In vivo attenuation and backscatter coefficients of normal human forearm dermis and subcutaneous fat were determined in the ranges 14 to 50 MHz and 14 to 34 MHz, respectively. Data were collected using three different transducers to ensure that results were independent of the measurement system. Attenuation coefficient was obtained by computing spectral slopes vs. depth, with the transducers axially translated to minimize diffraction effects. Backscatter coefficient was obtained by compensating recorded backscatter spectra for system-dependent effects and, additionally, for one transducer using the reference phantom technique. Good agreement was seen between the computed attenuation and backscatter results from the different transducers/methods. The attenuation coefficient of the forearm dermis was well described by a linear dependence with a slope that ranged between 0.08 to 0.39 (median = 0.21) dB mm(-1) MHz(-1). The backscatter coefficient of the dermis was generally in the range 10(-3) to 10(-1) Sr(-1) mm(-1) and showed an increasing trend with frequency. No significant differences in attenuation coefficient slope between the forearm dermis and fat were noted. Within the range of 14 to 34 MHz, the ratio of integrated (average) backscatter of dermis to that of fat ranged from 1.03 to 87.1 (median = 6.45), indicating significantly higher backscatter for dermis than for fat. Data were also recorded at the fingertip where the attenuation coefficient slope of the dermis was seen to be higher than that at the forearm.     

Ultrasound backscatter and attenuation in human liver with diffuse disease

Ultrasound backscatter and attenuation in the liver were measured in patients with diffuse liver disease and in 35 volunteers who had no history of liver ailments. Measurements were done using radiofrequency (RF) echo signals derived from a clinical scanner; a reference phantom was scanned to account for effects of gain, transmit-receive frequency response and transducer beam patterns on echo data. The mean backscatter coefficient at 3 MHz in livers of 7 patients with fatty infiltration was 6.8 x 10(-3) cm(-1)sr(-1) compared to a mean of 0.5 x 10(-3) cm(-1)sr(-1) in healthy patients. Mean attenuation at 3 MHz was 2.54 dB/cm in fatty livers compared to 1.66 dB/cm in healthy patients. A total of 7 patients with end-stage liver disease (cirrhosis) had attenuation values similar to those in the healthy group, and their mean liver backscatter was somewhat greater than the mean backscatter for healthy livers. Quantitating both backscatter and attenuation should be considered for detecting fatty infiltration; additional processing methods are needed to differentiate cirrhotic changes on the basis of acoustic signals.     

Measurement of the ultrasound attenuation and dispersion in whole human blood and its components from 0-70 MHz

The ultrasound attenuation coefficient and dispersion from 0-70 MHz in whole human blood and its components (red blood cells and plasma) at 37°C is reported. The measurements are made using a fixed path substitution technique that exploits optical mechanisms for the generation and detection of ultrasound. This allows the measurements to cover a broad frequency range with a single source and receiver. The measured attenuation coefficient and dispersion in solutions of red blood cells and physiological saline for total haemoglobin concentrations of 10, 15 and 20 g/dL are presented. The attenuation coefficient and dispersion in whole human blood taken from four healthy volunteers by venipuncture is also reported. The power law dependence of the attenuation coefficient is shown to vary across the measured frequency range. This is due to the varying frequency dependence of the different mechanisms responsible for the attenuation. The attenuation coefficient measured at high frequencies is found to be significantly higher than that predicted by historical power law parameters. A review of the attenuation mechanisms in blood along with previously reported experimental measurements is given. Values for the sound speed and density in the tested samples are also presented. (E-mail: btreeby@mpb.ucl.ac.uk)     

Relationships of ultrasonic backscatter with ultrasonic attenuation, sound speed and bone mineral density in human calcaneus

Ultrasonic attenuation and sound speed have been investigated in trabecular bone by numerous authors. Ultrasonic backscatter has received much less attention. To investigate relationships among these three ultrasonic parameters and bone mineral density (BMD), 30 defatted human calcanei were investigated in vitro. Normalized broadband ultrasonic attenuation (nBUA), sound speed (SOS), and logarithm of ultrasonic backscatter coefficient (LBC) were measured. Bone mineral density was assessed using single-beam dual energy x-ray absorptiometry (DEXA). The correlation coefficients of least squares linear regressions of the three individual ultrasound (US) parameters with BMD were 0.84 (nBUA), 0.84 (SOS) and 0.79 (LBC). The 95% confidence intervals for the correlation coefficients were 0. 69-0.92 (nBUA), 0.68-0.92 (SOS) and 0.60-0.90 (LBC). The correlations among pairs of US variables ranged from 0.63-0.79. Variations in nBUA accounted for r(2) = 62% of the variations in LBC. Variations in SOS accounted for r(2) = 40% of the variations in LBC. These results suggest that ultrasonic backscattering properties may contain substantial information not already contained in nBUA and SOS. A multiple regression model including all three US variables was somewhat more predictive of BMD than a model including only nBUA and SOS.     

Stimulation of reparative dentin formation by ex vivo gene therapy using dental pulp stem cells electrotransfected with growth/differentiation factor 11 (Gdf11)

Dental pulp progenitor/stem cells have the capacity to differentiate into odontoblasts and they provide a potential for dentin repair and regeneration by gene therapy. To develop a successful ex vivo gene therapy to induce reparative dentin formation rapidly and effectively after treatment of caries, we developed a three-dimensional pellet culture system of pulp cells electrotransfected with growth/differentiation factor 11 (Gdf11). The viability after electrotransfection was more than 85%, and the efficiency was about 70% as determined by flow cytometry. After 10 days of culture, the total amount of type I and type III collagen was 3-fold higher in the pEGFP-Gdf11-transfected pellet than in the control. Real-time RT-PCR analysis demonstrated that the expression of markers of odontoblast differentiation (alkaline phosphatase, dentin matrix protein 1 [Dmp1], dentin sialophosphoprotein [Dspp], enamelysin, and phosphate-regulating gene with homologies to endopeptidases on X-chromosome [Phex]) was increased in the pEGFP-Gdf11-transfected pellet compared with the control on day 14. On the basis of this in vitro evaluation, an in vivo investigation in the dog was performed. Autogenous transplantation of Gdf11-transfected cells cultured as a pellet on amputated pulp stimulated reparative dentin formation. Thus, Gdf11 gene therapy may be potentially used in endodontic treatment in dentistry.     

Radiofrequency-induced thermotherapy (RFiTT) in a porcine liver model and ex vivo great saphenous vein

Aims: To investigate the thermal spread achieved in porcine liver when using an optimised radiofrequency ablation protocol and correlate findings with the effects seen in ex vivo great saphenous vein (GSV), in order to justify clinical use with the new treatment protocol.

Material and methods: Porcine liver and GSV sections were treated with radiofrequency-induced thermotherapy (RFiTT) using the following settings: 20 W at 1?s/cm (linear endovenous energy density; LEED 20 J/cm), 18 W at 1?s/cm (LEED 18 J/cm), 18 W at 3?s/cm (LEED 54 J/cm), 6 W interrupted pull-back 6?s stationary every 0.5?cm (LEED 72 J/cm). Thermal spread in the liver was measured via digital imaging. GSV sections were sent to an independent laboratory for histological analysis. Previous work suggests a thermal spread of?>0.65?mm in liver correlates with transmural thermoablation of a GSV.

Results: Parameters giving a LEED of 72 J/cm produced the best results, with a clear transmural effect in the GSV and maximal thermal spread of 1.65?mm, without excessive thermal damage or carbonisation in the ablation tract.

Conclusions: Our porcine liver model correlated well with histological findings and was representative of the thermoablative effects observed in the GSV wall treated with RFiTT. Clinical investigations are now being carried out to investigate the efficacy of this protocol in the clinical setting.     

Diagnostic and prognostic significance of human kallikrein 11 (KLK11) mRNA expression levels in patients with laryngeal cancer

ObjectivesHuman kallikrein 11 gene (KLK11) encodes a secreted serine protease. In view of its diagnostic and prognostic strength in many malignancies, we investigated the mRNA expression levels of KLK11 in laryngeal tissues in order to unveil its clinical usefulness in laryngeal cancer.Design and methodsKLK11 expression was quantified in 163 tissue samples from 105 laryngeal cancer patients with the development of a highly sensitive real-time PCR methodology, using SYBR Green® chemistry.ResultsKLK11 expression in laryngeal cancer specimens of primary or recurrent nature was significantly inferior compared with their non-malignant counterparts (P < 0.001 and P = 0.026, respectively), a finding of immense diagnostic value as illustrated in the ROC curve analyses (P < 0.001). Survival analysis showed that patients harboring KLK11-positive tumors had a significantly decreased risk of death (HR = 0.26, P = 0.042).ConclusionsOur data recommend KLK11 mRNA expression as a novel and independent biomarker in laryngeal cancer for diagnostic and prognostic purposes.     

In vitro and in vivo intraleukocytic accumulation of azithromycin (CP-62, 993) and its influence on ex vivo leukocyte chemiluminescence.

The accumulation of azithromycin in phagocytic cells was studied both in vitro by using a radiolabelled drug and a bioassay and in vivo for 12 volunteers receiving 1.5 g (total dose) orally within 3 days. In vitro, neutrophils and unfractionated blood leukocytes accumulated azithromycin up to 160-fold the extracellular concentration within 1 h at 37 degrees C but less than 3-fold at 4 degrees C. Dead cells accumulated up to 30-fold azithromycin, whereas NaF-treated cells accumulated up to 60-fold arithromycin. The mean efflux from preloaded cells was at most 31.0% +/- 10.6% (standard error of the mean) of the cell-associated concentration within 4 h of incubation at 37 degrees C in drug-free buffer. In vivo, the azithromycin concentration was 45.2 +/- 6.1 mg/liter of intracellular fluid at 2 h after the third dose and 36.6 +/- 8.3 mg/liter at 1 week thereafter. The corresponding concentrations in serum were 0.2 +/- 0.1 (2 h) and less than 0.05 (1 week). The luminol-enhanced chemiluminescence response induced by phorbol myristate acetate, opsonized zymosan, and two opsonized strains of Haemophilus influenzae (a type b capsulated strain and a noncapsulated strain) was also studied ex vivo by using the blood leukocytes from the 12 test volunteers and 4 control volunteers at 2 and 6 h after the third oral dose of azithromycin and at 2, 4, and 7 days thereafter. Azithromycin did not influence this response despite high levels of cellular accumulation.     

Motion-artifact-robust,polarization-resolved second-harmonic-generation microscopy based on rapid polarization switching with electro-optic Pockells cell and its application to in vivo visualization of collagen fiber orientation in human facial skin

Polarization-resolved second-harmonic-generation (PR-SHG) microscopy is a powerful tool for investigating collagen fiber orientation quantitatively with low invasiveness. However, the waiting time for the mechanical polarization rotation makes it too sensitive to motion artifacts and hence has hampered its use in various applications in vivo. In the work described in this article, we constructed a motion-artifact-robust, PR-SHG microscope based on rapid polarization switching at every pixel with an electro-optic Pockells cell (PC) in synchronization with step-wise raster scanning of the focus spot and alternate data acquisition of a vertical-polarization-resolved SHG signal and a horizontal-polarization-resolved one. The constructed PC-based PR-SHG microscope enabled us to visualize orientation mapping of dermal collagen fiber in human facial skin in vivo without the influence of motion artifacts. Furthermore, it implied the location and/or age dependence of the collagen fiber orientation in human facial skin. The robustness to motion artifacts in the collagen orientation measurement will expand the application scope of SHG microscopy in dermatology and collagen-related fields.OCIS codes: (170.1870) Dermatology, (170.3880) Medical and biological imaging, (190.4160) Multiharmonic generation, (180.4315) Nonlinear microscopy     

Platelet response to the aggregatory effect of platelet activating factor (PAF) ex vivo in patients with acute myocardial infarction

Platelets from patients with acute myocardial infarction exhibit an increased sensitivity to the aggregatory effect of PAF, in vitro, the first 48 h after the onset of the symptoms. This sensitivity, expressed as PAF EC50 values, seems to be transient after the 2 day period. Also, a remarkable decreased sensitivity to the inhibitory effect of PGI2 against the aggregation induced by PAF appears to the platelets of those patients the first hours after the onset of the symptoms, and persists for at least 14 days. Treatment of patients by drugs with a known inhibitory effect on platelet aggregation in vivo and in vitro (aspirin, nifedipine, indomethacin), does not influence the increase in platelet sensitivity to PAF, but inhibits the secondary aggregation induced by the released aggregating factors from the PAF activated platelets. The increase in platelet sensitivity to PAF is not unique to the AMI since it is also observed in patients with acute bacterial pneumonia. However, we cannot support the theory that it is a general phenomenon of acute tissue injury since it is general phenomenon of acute tissue injury since it is not observed in patients with acute muscular injury.     

二例伴有dic(9;20)(p11-13;q11)急性淋巴细胞白血病患者的临床和实验研究

目的探讨伴有dic（9;20）（p11-13;q11）的急性淋巴细胞白血病（ALL）的细胞形态学、免疫学、细胞遗传学特征和临床特点.方法骨髓细胞经直接法和24h短期培养后按常规方法制备染色体,采用R显带技术进行细胞遗传学分析.分别以9号和20号染色体着丝粒探针进行双色荧光原位杂交（FISH）检测.结果2例患者的临床和血液学改变符合ALL诊断,免疫表型分析B淋系标志阳性（CD10＋、HLA-DR＋）;染色体核型分析显示2例患者均为dic（9;20）：例1为45,XY,der（9）t（9;20）（p11;q11）,-20[20],例2为45,XX,der（9）t（9;20）（p13;q11）,t（9;22）（q34;q11）,-20[10]/46,idem,＋8[16]/47,idem,＋8,＋21[14];其中1例经双色FISH检测证实9号和20号染色体之间发生了相互易位,且形成双着丝粒染色体.结论dic（9;20）（p11-13;q11）是一种少见的重现性核型异常,可能和ALL有特殊的联系.FISH技术是检测该易位的可靠手段.     

Recombinant human interleukin-11 restores smooth muscle function in the jejunum and colon of human leukocyte antigen-B27 rats with intestinal inflammation

Recombinant human interleukin (rhIL)-11 has anti-inflammatory and protective effects in models of intestinal mucosal injury. Our aim was to investigate whether oral treatment with rhIL-11 reverses functional abnormalities in intestinal muscle contractility resulting from human leukocyte antigen (HLA)-B27-dependent gut inflammation. Isometric contractions were studied in jejunal and colonic longitudinal muscles. Muscle strips were isolated from HLA-B27 transgenic rats with spontaneous inflammation following treatment with enteric-coated rhIL-11 multiparticulates (500 microg/kg) or placebo multiparticulates given orally every 48 h for 2 weeks. Myeloperoxidase (MPO) activity was measured in intestinal tissue samples and served as an index of inflammation. Colonic damage was also assessed histologically. The HLA-B27 rats receiving placebo had chronic diarrhea, and MPO activity was increased in the jejunum and colon. Intestinal inflammation was associated with a decreased ability of the muscles to generate active tension in response to electrical field stimulation, carbachol, or high KCl. In the jejunum of placebo-treated HLA-B27 rats, concentration-effect curves for carbachol were shifted to lower concentrations yielding a higher EC50. Oral treatment of HLA-B27 rats with rhIL-11 suppressed the symptoms of diarrhea, normalized MPO activity, and improved the colonic damage score. Simultaneously, neurally mediated responses were improved and the maximal tension generated by carbachol or KCl was normalized in the jejunum and colon. The EC50 for carbachol in the jejunum of HLA-B27 rats was also normalized by rhIL-11 treatment. Our data demonstrate that oral administration of enteric-coated rhIL-11 suppresses intestinal inflammation and reverses intestinal smooth muscle dysfunction in HLA-B27 transgenic rats.     

In vitro and in vivo effects of 14alpha-demethylase (ERG11) depletion in Candida glabrata

Sterol 14alpha-demethylase (ERG11) is the target enzyme of azole antifungals that are widely used for the treatment of fungal infections. Candida glabrata is known to be less susceptible to fluconazole than most Candida albicans strains, and the incidence of C. glabrata infection has been increasing mostly in conjunction with the use of azole antifungals. Recently, it has been reported that C. glabrata can rescue the defect of ergosterol biosynthesis by incorporating cholesterol from serum. To explore the effect of inactivating Erg11p in C. glabrata, we generated mutant strains in which the ERG11 gene was placed under the control of tetracycline-regulatable promoters. In these mutants, expression of the ERG11 gene can be repressed by doxycycline (DOX). All mutants showed a growth defect in the presence of DOX. The numbers of CFU of the mutants were lowered by only 1/10 with DOX treatment. In these mutants, accumulation of 4,14-dimethylzymosterol, which differs from an accumulated abnormal sterol detected in C. albicans and Saccharomyces cerevisiae treated with fluconazole, was observed by DOX treatment. Although such phenotypes were also observed in serum-containing media by DOX treatment, they were alleviated. Furthermore, the mutant could grow in DOX-treated mice without a severe reduction in the number of cells. Thus, depleting the expression of the ERG11 gene lowered the number of CFU by only 1/10 due to the accumulation of 4,14-demethylzymosterol in vitro, and it did not result in the defective growth of fungal cells in mice. These results suggested that Erg11p is not an ideal target molecule of antifungals for C. glabrata.     

Prostacyclin analogue (OP-2507) induces delayed ex vivo neutrophil apoptosis and attenuates reperfusion-induced hepatic microcirculatory derangement in rats

Leukocyte-endothelial adherence and changes of blood flow in microcirculation are associated with the development of ischemia-reperfusion injury in the liver. Polymorphonuclear neutrophil (PMN) apoptosis is essential to maintain homeostasis and plays a major role in limiting the reperfusion-related systemic effects. This study investigates the effects of a prostacyclin analogue (OP-2507) on hepatic ischemia-reperfusion injury. Adult, male Sprague-Dawley rats were used. Five groups were evaluated: (1) sham-operated control, n = 8; (2) ischemia control (1-h ischemia, 5-h reperfusion), n = 8; (3) intravenous infusion with OP-2507 ([15 cis-14-propylcyclohexyl]-16,17,18,19,20-pentanor-9-deoxy-9alpha,6-ni-trilo-PGF, methyl eater) at a dose of 1 microg/kg/min plus ischemia, n = 8; (4) intravenous infusion with OP-2507 at a dose of 0.1 microg/kg/min plus ischemia, n = 8, and (5) sham-operated control and intravenous infusion with OP-2507 at a dose of 1 microg/kg/min, N =8. Laser-Doppler flowmetry and an in vivo microscopy were used to investigate hepatic microcirculation. PMN apoptosis was quantitated by flow-cytometric labeling of DNA strand breaks. Tissue malondialdehyde and adenosine triphosphate were determined at the end of the experiment. Compared with the ischemia control group, OP-2507 significantly improved harmful insults following ischemia-reperfusion. The changes of mean systemic arterial pressure following ischemia-reperfusion have been significantly attenuated by OP- 2507 at both doses. OP-2507 lessened adherent leukocyte count in the post-sinusoid venules, and improved flow velocity in these areas. OP-2507 at both doses reduced malondialdehyde and increased adenosine triphosphate levels and this effect was dose-related. The activity of delayed ex vivo PMN apoptosis was significantly lower in the ischemia group than that of control and treatment groups. OP-2507 induced the activity of PMN apoptosis and its effect is dose-related, also. The PMN apoptosis activity is strongly correlated with parenchymal damages. This study demonstrates that OP-2507 treatment with ischemia may ameliorate the ischemia-reperfusion injury of the liver in the rat model, and increase spontaneous neutrophil apoptosis ex vivo.     

The effect of azithromycin and clarithromycin on ex vivo interleukin-8 (IL-8) release from whole blood and IL-8 production by human alveolar macrophages

We investigated the effects of azithromycin and clarithromycin, two antibiotics that possess a broad spectrum of antimicrobial activity (including antimycobacterial activity), on interleukin-8 (IL-8) release from human whole blood leucocytes and lung macrophages. Ex vivo stimulation of leukocytes with either of the antibiotics (0.04-40 mg/L) significantly increased IL-8 secretion. Incubation of alveolar macrophages with different concentrations of azithromycin or clarithromycin modified IL-8 production: it increased at a drug concentration of 4 mg/L and decreased at concentration of 400 mg/L. Our findings suggest that azithromycin and clarithromycin may alter IL-8 production, thus enhancing the clinical effectiveness of these antibiotics.     

Analysis of (R)- and (S)-[11C]rolipram Kinetics in Canine Myocardium for the Evaluation of Phosphodiesterase-4 with PET

Purpose  

(R)-[¹¹C]rolipram and (S)-[¹¹C]rolipram have been proposed to investigate phosphodiesterase-4 and, indirectly, cAMP-mediated signaling with PET. This study assessed binding of these tracers to phosphodiesterase-4 in canine myocardium.     

分子影像在人类肿瘤基因治疗中的应用

近年来，分子影像技术对基因表达进行监测已得到一定程度的发展并成功应用于动物模型研究，但尚需进一步评估它们在人体试验中的灵敏度和可重复性。本文综述了当前的分子成像技术特别是放射性核素显像在人类肿瘤基因治疗中的应用现状。