Multimodal real-time imaging with laser speckle contrast and fluorescent contrast

INTRODUCTION

Laser speckle contrast imaging (LSCI) can achieve real-time 2D perfusion maps non-invasively. However, LSCI is still difficult to use in general clinical applications because of movement sensitivity and limitations in blood flow analysis. To overcome this, fluorescence imaging (FI) is combined with LSCI using a light source with a wavelength of 785 nm in near-infrared (NIR) region and validates to visualize real-time blood perfusion.

MATERIALS AND METHODS

The system was performed using Intralipid and indocyanine green (ICG) in a flow phantom that has three tubes and controlled the flow rate in 0-150 μl/min range. First, real-time LSCI was monitored and measured the change in speckle contrast by reperfusion. Then, we visualized blood perfusion of a rabbit ear under the non-invasive condition by intravenous injection using a total of five different ICG concentration solutions from 128 μM to 3.22 mM.

RESULTS

The combined system achieved the performance of processing laser speckle images at about 37-38 fps, and we simultaneously confirmed the fluorescence of ICG and changes in speckle contrast due to intralipid as a light scatterer. In addition, we obtained real-time contrast variation and fluorescent images occurring in rabbit's blood perfusion.

CONCLUSIONS

The aim of this study is to provide a real-time diagnostic imaging system that can be used in general clinical applications. LSCI and FI are combined complementary for observing tissue perfusion using a single NIR light source. The combined system could achieve real-time visualization of blood perfusion non-invasively.

Comparative study of new autologous material, bone-cartilage composite graft, for ossiculoplasty with Polycel® and Titanium

OBJECTIVE

Ossiculoplasty is a surgical procedure that recreates sound transmission of the middle ear in conductive hearing loss. Various materials have been used for ossicular reconstruction, but the most ideal material for ossiculoplasty remains controversial. The purpose of this study was to introduce a novel method of autologous ossiculoplasty, bone-cartilage composite graft (BCCG) and to compare its surgical results with different types of ossiculoplastic prostheses.

STUDY DESIGN

A retrospective study was performed in a tertiary referral centre.

METHODS

Data of 275 patients who received ossiculoplasty using the three different materials of BCCG, Polycel^® and titanium were analysed according to type of ossiculoplasty: partial or total ossicular replacement prosthesis (PORP or TORP). Hearing results, complication rates and clinical parameters including age, sex, past history, preoperative diagnosis and surgery type were compared among different groups.

RESULTS

Ossiculoplasty with BCCG showed satisfactory hearing outcomes and the lowest complication rate among the three different materials. In particular, its extrusion rate was 0%.

CONCLUSION

We propose that the BCCG technique is a useful alternative method for ossiculoplasty, with proper patient selection.

Preoperative detection and predictors of level V lymph node metastasis in patients with papillary thyroid carcinoma

Background

Papillary thyroid carcinoma (PTC) frequently metastasizes to regional lymph nodes. Metastasis to the posterior neck, level V, is uncommon, and level V lymphadenectomy may lead to spinal accessory nerve injury and associated postoperative morbidities. The aim of this study was to assess the diagnostic efficiency of preoperative ultrasonography and to identify predictors of level V metastasis in patients with PTC.

Methods

This study involved patients with previously untreated PTC that had metastasized to the lateral neck, and who underwent total thyroidectomy with central and lateral neck dissection. Histopathological findings were compared with ultrasound results for various neck levels. Clinical and histopathological factors that predicted level V metastasis were identified.

Results

Of 143 patients, 26 (18·2 per cent) had lymph node metastasis at level V. The sensitivity and positive predictive value of ultrasonography for level V metastasis were 46·2 and 30·0 per cent respectively. Univariable analysis showed that male sex, extranodal disease extension, a metastatic lymph node ratio in the ipsilateral lateral neck of more than 0·2, and simultaneous involvement of ipsilateral levels II–IV or level III were associated with ipsilateral level V metastasis. Multivariable analysis revealed an independent association between macroscopic extranodal disease extension and level V metastasis (odds ratio 26·05, 95 per cent confidence interval 5·63 to 120·56; P < 0·001).

Conclusion

Preoperative ultrasonography frequently failed to detect level V metastasis in patients with metastatic PTC. Level V lymphadenectomy may be considered in patients with lymph node metastasis in the ipsilateral lateral neck with macroscopic extranodal extension.

Mycelial protoplast isolation and regeneration of Lentinus lepideus

Generation of fungal protoplast is essential for fusion and transformation systems. Protoplast fusion offers great potential for the improvement of industrially important microorganisms. To establish conditions for the protoplast isolation and regeneration of the mycelia of Lentinus lepideus, various enzymes and osmotic stabilizers were examined. To investigate suitable medium for the culture of L. lepideus, the mycelia were grown in ten different media at 28 degrees C for 10 days. Among them potato dextrose agar (PDA) medium was found to be the best for colony growth. When Novozym 234, cellulase and beta-glucuronidase were added to the mycelia in combination or alone, Novozym 234 alone at the concentration of 10 mg/ml was the most effective for the protoplast yield. Purified spherical protoplasts of the mycelia were osmotically hypersensitive and further incubation of the mycelia with the lytic enzyme resulted in the older parts of the hyphae swollen. When we applied various osmotic stabilizers at the fixed concentration of 0.6 M on the protoplasts, the yields of protoplasts were increased until 4-hr incubation. However application of sucrose or MgSO4 led to further protection of protoplasts after that time and reached a plateau on 5- and 7-hr incubations, respectively. The suitable incubation time and optimal pH with the lytic enzyme for the maximum release of protoplasts were 6 hrs of incubation and pH 5, respectively. When we examined various osmotic stabilizers for the regeneration of the protoplast, the complete medium containing 0.6 M sucrose induced highest hyphal growth with regeneration frequency of 3.28%.

High vulnerability of GABA-immunoreactive neurons to kainate in rat retinal cultures: correlation with the kainate-stimulated cobalt uptake

Like other areas of the central nervous system, the retina is highly vulnerable to ischemia. In particular, neurons in the inner nuclear layer, including gamma-amino butyric acid (GABA)-ergic amacrine neurons, are highly vulnerable. Since excitotoxicity is likely a major mechanism of ischemic retinal injury, using rat retinal cell culture, we examined whether GABAergic retinal neurons are differentially vulnerable to particular excitotoxins. The neuronal population as a whole, identified by anti-microtubule associated protein-2 (MAP-2) immunocytochemistry, was equally vulnerable to kainate, but more resistant to N-methyl-d-aspartate (NMDA) than cultured cortical neurons. Compared to Thy-1 immunoreactive neurons, GABA immunoreactive neurons were more vulnerable to kainate, but more resistant to NMDA neurotoxicity. Double staining of cultures with anti-GABA immunocytochemistry and the kainate-stimulated cobalt uptake method, revealed a close correlation between the two. However, unlike in other neuronal cells, there was no clear correlation between GluR2 immunoreactivity and the cobalt staining. The heightened vulnerability of GABAergic neurons to kainate, as compared to the general neuronal population, may be due to the calcium-permeable AMPA/kainate receptors they have, as identified functionally by the kainate-stimulated cobalt uptake staining. Since these neurons are preferentially injured in ischemia, AMPA/kainate receptor-mediated neurotoxicity may contribute significantly to ischemic retinal injury.

Protective effect of taurine on TNBS-induced inflammatory bowel disease in rats

We had previously reported that the protective effect of taurine against indomethacin-induced gastric mucosal injury was due to its antioxidant effects, which inhibited lipid peroxidation and neutrophil activation. In this study, we examined the effect of taurine on reducing the inflammatory parameters of trinitrobenzene sulfonic acid (TNBS)-induced inflammatory bowel disease (IBD) in rats. In order to induce IBD, ethanolic TNBS was given to rats intracolonically. Then they received 500 mg/kg/day of taurine orally and were sacrificed one week after IBD induction. While ulceration and inflammation of distal colon with formation of granuloma in the vehicle-treated IBD rats two days after administration of TNBS were observed, treatment with taurine ameliorated colonic damage and decreased the incidence of diarrhea and adhesion. Also, colon weight as an index of tissue edema, which was markedly increased in the IBD rats, became significantly lower after taurine treatment. Myeloperoxidase (MPO) activity in the vehicle-treated IBD rats was substantially increased, compared with that of normal control. The taurine-treated animals significantly reduced MPO activity (35% lower) when compared with that of the vehicle-treated animals. Taurine treatment decreased both basal and formyl-methionyl leucyl phenylalanine-stimulated reactive oxygen generation from colonic tissue in the IBD rats. These results suggest that the administration of taurine reduce the inflammatory parameters in this IBD rat model by increasing defending capacity against oxidative damage.

Effects of steroid hormones and cyclosporine A on taurine-transporter activity in the RAW264.7 cell line

The activity of the taurine transporter is affected by various extracellular stimuli, such as ions, hormones and stress. To assess the effects of steroid hormones and cyclosporine A (CsA) on taurine-transporter activity, the murine monocytic cell line, RAW264.7, was stimulated with dexamethasone (DM), triamcinolone (TA), cortisone (CS), hydrocortisone (HCS), prednisone (PSN), prednisolone (PSL) and methylprednisolone (MPSL) in the presence of 12-O-tetradecanoylphorbol 13-acetate (TPA). Treatment of the cell with TPA led to a significant reduction in taurine-transporter activity. However, in the case of the stimulation of the cells with steroid hormones in the presence of TPA, all of the hormones reversed the TPA-induced reduction in the taurine-transporter activity. Treatment of the cells with CsA led to a significant reduction in taurine-transporter activity, but ionomycin (IM) alone did not affect taurine-transporter activity. However, IM reversed the TPA- and CsA-induced reduction in taurine-transporter activity. These results showed that both IM and the glucocorticoid hormones reversed TPA-induced reductions in taurine-transporter activity but only IM reversed the CsA-induced reduction of transporter activity in the RAW264.7 cell line.

Redundant use of luminance and flashing with shape and color as highlighting codes in symbolic displays

Three visual search experiments evaluated the benefits and distracting effects of using luminance and flashing to highlight subclasses of symbols coded by shape and color. Each of three general shape/color classes (circular/blue, diamond/red, square/yellow) was divided into three subclasses by presenting the upper half, lower half, or entire symbol. Increasing the luminance of a subclass by a factor of two did not result in a significant improvement in search performance. Flashing a subclass at a rate of 3 Hz resulted in a significantly shorter mean search time (48% improvement). Increasing the luminance of one subclass (by a factor of five) while simultaneously flashing another significantly improved search times by 31% and 43% respectively, compared with nonhighlighted search conditions. In each experiment, the search times for nonhighlighted target subclasses were not affected by the presence of brighter and flashing targets. The failure of the initial experiment to find a significant performance improvement caused by increasing symbol luminance suggested that a larger luminance increase was necessary for this code to be effective. The overall results suggest that using luminance and flashing to highlight subclasses of color- and shape-coded symbols can reduce search times for these subclasses without producing a distraction effect by way of a concomitant increase in the search times for unhighlighted symbols.

Effect of extraneous targets on identification of color-coded targets

Subjects matched the color of a vertical target line, presented in 1 of 10 colors, to a set of 10 colors. The target line was presented either in isolation or together with 5 additional colored lines. Neither mean reaction time nor the number of matching errors increased when the extraneous lines were present, and the types of color confusions did not change systematically.