Self-referenced spectral interferometry for simultaneous measurements of thickness and refractive index

We present a method for simultaneously measuring the thickness and the group refractive index of a specimen using self-referenced spectral-domain fiber-based interferometry. By removing the scanning part and using the fiber-based configuration, the system complexity and stability could be significantly improved. To minimize the system drift, we utilized the signals originated from the fiber ends of both arms. Implementing in a self-referenced configuration, we could improve the measurement accuracy down to a decimal place. Experimental measurements were made with a 1.555 mm thick fused silica plate. At 814 nm the thickness was measured as 1.5546 +/- 0.0002 mm, and at the same time, the group index was obtained as 1.4627 +/- 0.0002.

Thin multi-walled carbon nanotubes synthesized by rapid thermal chemical vapor deposition and their field emission properties

Thin multi-walled carbon nanotubes (MWCNTs) were successfully synthesized by a rapid thermal chemical vapor deposition (RTCVD) method using a liquid catalyst. The growth of the thin MWCNTs was achieved by decomposition of C2H2 over Fe-Mo/MgO/citric acid directly at 700 degrees C for 30 min. Most thin MWCNTs, which had about 6 approximately 8 graphene layers, showed high purity (approximately 90%) and good crystallinity. Moreover, they showed homogenous morphology and uniform diameters. The average outer diameter of the thin MWCNTs was about 8 nm. The uniform diameter and good homogeneity of thin MWCNTs were mainly attributed to prevention of catalyst agglomeration at high temperature due to a short reaction time, and the high purity of thin MWCNTs was caused by suppression of the residual CNT growth after finishing a reaction in RTCVD process. Field emission properties of the thin MWCNTs were measured in a vacuum chamber at a pressure of less than 2 x 10(-7) Torr. The turn-on field was about 3.35 V/microm at the emission current density of 0.1 microA/cm2, and the emission current density was 2.5 mA/cm2 at an applied field of 6.7 V/microm. Particularly, the thin MWCNTs showed strong emission stability at emission current density of 0.8 mA/cm2 for 20 h.

Expression of IL-10, TGF-beta(1) and TNF-alpha in Cultured Keratinocytes (HaCaT Cells) after IPL Treatment or ALA-IPL Photodynamic Treatment

BACKGROUND

Depending on the light dose and concentration of photosensitizer for photodynamic treatment (PDT), a multitude of dose-related events are demonstrable in PDT-treated cells. Sublethal doses may result in the alteration of cytokine release and consequently modify immune actions, rather than cause cell death.

OBJECTIVE

The purpose of this study was to investigate cytokine expression in cultured HaCaT cells after intense pulse light (IPL) treatment or PDT utilizing 5-aminolevulinic acid (ALA) and IPL at sublethal doses.

METHODS

Cultured HaCaT cells were treated with either IPL only (4, 8 and 12 J/cm(2)) or ALA-IPL PDT (100micromol/L of ALA; 0, 4, 8, and 12 J/cm(2) of IPL). The expression of IL-10, TGF-beta(1) and TNF-alpha was investigated by reverse transcription-polymerase chain reaction and enzyme linked immunosorbent assay.

RESULTS

IL-10 protein increased up to 5.95-fold after IPL treatment and up to 2.85-fold after PDT. TGF-beta(1) mRNA and protein showed slight increases after both IPL treatment and PDT, of which the latter induced slightly larger increases. TNF-alpha mRNA and protein showed no induction or reduction after PDT.

CONCLUSION

Increased expressions of IL-10 and TGF-beta(1) was observed after PDT. The induction of IL-10 may contribute to the anti-inflammatory effect, which explains the therapeutic benefit of PDT for inflammatory dermatoses, and that of TGF-beta(1) may be related to the therapeutic effect for psoriasis. The finding that IL-10 induction was more marked after IPL treatment than after PDT suggests that other mechanisms than IL-10 induction in keratinocytes after PDT may participate in the anti-inflammatory effect of PDT.

A Case of Dedifferentiated LiposarcomaThat Developed in the Dermis

Dedifferentiated liposarcoma is a variant of liposarcoma, and this is characterized by the coexistence of well-differentiated liposarcoma with areas of poorly differentiated, non-lipogenic tumor and this is also known to be associated with more aggressive behavior. Dedifferentiated liposarcoma occurs principally in the retroperitoneum or the deep soft tissue of limbs, but it can also occur in subcutaneous locations. We report here on a peculiar case of dedifferentiated liposarcoma that developed in the dermis, which is an exceedingly rare location for this type of tumor. The occurrence of this tumor in the dermis made it easy to surgically remove and monitor for recurrence, and we expect this patient to have a better prognosis than that of a patient with dedifferentiated liposarcoma located in the retroperitoneum or deep soft tissue.

A Case of Dermatitis Neglecta

Dermatitis neglecta (unwashed dermatosis) presents as pigmented hyperkeratotic plaques with adherent scales which clinically resembles psoriasis. This condition is the result of avoiding washing the affected areas, so the lesions are characteristically resolved with normal washing or with gentle wiping from an alcohol swab. We report a 29-year-old man who presented with an asymptomatic hyperkeratotic scaly plaque on umbilicus. A skin biopsy was done under the clinical impression of psoriasis. During skin biopsy, gentle swabbing with H2O2 and saline gauze was done. The patient revisited our clinic 10 days after the skin biopsy and the hyperkeratotic lesion had cleared. Histologic examination showed orthokeratotic hyperkeratosis and anastomosing rete ridges. There has been no previous report of dermatitis neglecta with histologic confirmation, and so this case could be the first report to provide the histologic characteristics of dermatitis neglecta. Because this condition might be overlooked and underdiagnosed, recognizing its existence and cause are important to avoid unnecessary biopsies and potentially aggressive therapeutic measures.

Miniature fiber-optic high temperature sensor based on a hybrid structured Fabry-Perot interferometer

A miniature Fabry-Perot (FP) interferometric fiber-optic sensor suitable for high-temperature sensing is proposed and demonstrated. The sensor head consists of two FP cavities formed by fusion splicing a short hollow-core fiber and a piece of single-mode fiber at a photonic crystal fiber in series. The reflection spectra of an implemented sensor are measured at several temperatures and analyzed in the spatial frequency domain. The experiment shows that the thermal-optic effect of the cavity material is much more appreciable than its thermal expansion. The temperature measurements up to 1000 degrees C with a step of 50 degrees C confirm that it could be applicable as a high-temperature sensor.

Combined system of optical coherence tomography and fluorescence spectroscopy based on double-cladding fiber

We report the development of an all-fiber multimodal system, based on a double-cladding fiber (DCF) and related devices, suitable for simultaneous measurements of optical coherence tomography (OCT) and fluorescence spectroscopy (FS). The DCF together with a DCF coupler and a single-body DCF lens has assisted in the realization of a multimodal but single-unit probe for the combined system. The DCF lens allowed simultaneous focusing of input beams for OCT and FS and also the effective collection of both signal beams from a sample. The DCF coupler could extract the OCT signal via the core channel and the FS signal through the cladding channel. The OCT image and the fluorescence spectra of a plant tissue were then simultaneously measured to validate the performance of the proposed multimodal system.

Neurosurgical aspects of sedimentation levels in acute intracerebral haematoma

We describe the neurosurgical aspects of sedimentation levels that are rarely found in acute intracerebral haematomas (ICH). We had four patients with acute ICH whose cerebral computed tomography revealed sedimentation levels. Two patients had received thrombolytic therapy for ischaemic heart disease and one for ischaemic stroke. Another patient, who was diagnosed later as having a coagulation disorder, did not have any medical history on admission. All patients had emergency ICH drainage under local anaesthesia. In the immediate postoperative period, we observed dramatic improvement in all the patients, without surgical complications. The sedimentation level in an ICH should be identified as a specific indicator of a coagulation defect and a thorough search for possible underlying coagulopathy is warranted. We believe that simple ICH drainage should be performed as the haematoma is in a liquid form.

Photonic crystal fiber interferometer composed of a long period fiber grating and one point collapsing of air holes

We present an all-fiber interferometer fabricated with a single piece of an endless single-mode photonic crystal fiber (PCF) by an electric arc discharge. By forming a long period grating (LPG) at a point and collapsing the air holes at another point along the PCF, the simple but effective interferometer could be implemented. The LPG made a strong wavelength selective mode coupling between the core and cladding modes in the interesting wavelength range, while the air-hole collapse induced wavelength independent mode couplings. By cascading them, we could implement the all-fiber interferometer. As a potential application of the proposed all PCF interferometer, strain sensing is experimentally demonstrated.

Lensed fiber probes designed as an alternative to bulk probes in optical coherence tomography

We demonstrate a compact all-fiber sampling probe for an optical coherence tomography (OCT) system. By forming a focusing lens directly on the tip of an optical fiber, a compact sampling probe could be implemented. To simultaneously achieve a sufficiently long working distance and a good lateral resolution, we employed a large-mode area photonic crystal fiber (PCF) and a coreless silica fiber (CSF) of the same diameters. A working distance of up to 1270 microm, a 3 dB distance range of 2210 microm, and a transverse resolution of 14.2 microm were achieved with the implemented PCF lensed fiber; these values are comparable to those obtainable with a conventional objective lens having an NA of 0.25 (10 x). The performance of the OCT system equipped with the proposed PCF lensed fiber is presented by showing the OCT images of a rat finger as a biological sample and a pearl as an in-depth sample.

Single-body lensed photonic crystal fibers as side-viewing probes for optical imaging systems

We report the fabrication and performance of a lensed photonic crystal fiber (PCF) designed as a compact but effective side-viewing optical imaging probe. The lensed-PCF probe was implemented in a single body without using any other fibers or additional optics. The beam expansion region and a focusing ball lens, necessary for a focuser, were simultaneously formed along a small piece of PCF by applying arc discharges. The side-viewing ability was provided by polishing the ball lens with a femtosecond laser to form a total internal reflection surface. The working distance and the transverse resolution of the fabricated single-body lensed-PCF were experimentally measured to be 570 and 6.8 microm, respectively. With the proposed lensed-PCF probe, optical coherence tomography images of an in vitro biological sample were successfully obtained.

Optical probe based on double-clad optical fiber for fluorescence spectroscopy

We report an optical probe based on a single double-clad fiber (DCF), which is suitable for fluorescence spectroscopy. The excitation light is delivered through the small diameter core of the DCF and the excited fluorescence light is collected by the large diameter inner cladding of the same fiber. To retrieve the signal beam from the inner cladding, we utilize a DCF coupler that couples only the light beams in the inner claddings of two different pieces of DCF. It was found that the separation of the channel for the excited beam from the channel for the excitation beam in the same piece of fiber could diminish the autofluorescence background noise generated by the fiber itself, while maintaining all the benefits of a single-fiber probe system. The usefulness of the DCF probe and the performance of the DCF coupler are then reported by presenting the fluorescence spectrum of a fresh gingko leaf and comparing it with the spectrum taken with conventional methods. The fabrication process of the DCF fiber and the inner cladding mode coupler for it are also presented.

Thrombus volume comparison between patients with and without hyperattenuated artery sign on CT

BACKGROUND AND PURPOSE

Although the hyperattenuated middle cerebral artery sign is known to be related to acute infarction, the volume of clot associated with it is not known. We investigated whether the presence or absence of hyperattenuated artery sign (HAS) on noncontrast CT (NCCT) can predict the thrombus volume.

MATERIALS AND METHODS

We enrolled 90 consecutive patients with acute infarction who underwent both 5- and 1.25-mm NCCT and CT angiography (CTA). HAS was determined on 5-mm NCCT retrospectively. According to the location of thrombi, the patients were classified into ICA (ICA terminus/ICA and others), M1 (M1/both M1 and M2), and M2 (M2) groups. Thrombus volumes were measured by 1.25-mm NCCT and were compared between patients with and without HAS.

RESULTS

Occlusion of major arteries was seen on CTA in 78 patients. HAS was found in 46 patients (59.0%). The mean thrombus volume was significantly larger in patients with HAS than in those without except for the M2 group (ICA group: [n = 14], 188.7 +/- 122.5 mm(3) versus 39.4 +/- 12.1 mm(3) [P = .022]; M1 group: [n = 42], 128.1 +/- 119.2 versus 56.8 +/- 32.5 [P = .005]; M2 group: [n = 22], 34.7 +/- 32.2 versus 20.0 +/- 20.0 [P = .18]). Thrombus volumes determined by receiver operating characteristic curve analysis were 52.36 mm(3) in the ICA group (sensitivity, 90.9%; specificity, 100%) and 53.96 mm(3) in the M1 group (sensitivity, 88.0%; specificity, 58.8%).

CONCLUSION

Thrombus volumes were significantly larger in patients with HAS than in those without in ICA and M1 occlusions. The detection of HAS may provide an idea concerning rapid and dichotomized estimation of thrombus volume, which may be helpful for treatment decisions in potential candidates for thrombolysis.

Podocyte biology in diabetic nephropathy

Glomerular visceral epithelial cells, namely podocytes, are highly specialized cells and give rise to primary processes, secondary processes, and finally foot processes. The foot processes of neighboring podocytes interdigitate, leaving between them filtration slits. These are bridged by an extracellular substance, known as the slit diaphragm, which plays a major role in establishing size-selective barrier to protein loss. Furthermore, podocytes are known to synthesize matrix molecules to the glomerular basement membrane (GBM), including type IV collagen, laminin, entactin, and agrin. Because diabetic nephropathy is clinically characterized by proteinuria and pathologically by glomerular hypertrophy and GBM thickening with foot process effacement, podocytes have been the focus in the field of research on diabetic nephropathy. As a result, many investigations have demonstrated that the diabetic milieu per se, hemodynamic changes, and local growth factors such as transforming growth factor-beta and angiotensin II, which are considered mediators in the pathogenesis of diabetic nephropathy, induce directly and/or indirectly hypertrophy, apoptosis, and structural changes, and increase type IV collagen synthesis in podocytes. This review explores some of the structural and functional changes of podocytes under diabetic conditions and their role in the development and progression of diabetic nephropathy.

Simultaneous monitoring technique for ASE and MPI noises in distributed Raman Amplified Systems

We develop a new technique for simultaneously monitoring the amplified spontaneous emission (ASE) and multi-path interference (MPI) noises in distributed Raman amplified (DRA) systems. This technique utilizes the facts that the degree-of polarization (DOP) of the MPI noise is 1/9, while the ASE noise is unpolarized. The results show that the proposed technique can accurately monitor both of these noises regardless of the bit rates, modulation formats, and optical signal-to-noise ratio (OSNR) levels of the signals.

All-fiber Mach-Zehnder type interferometers formed in photonic crystal fiber

We propose simple and compact methods for implementing all-fiber interferometers. The interference between the core and the cladding modes of a photonic crystal fiber (PCF) is utilized. To excite the cladding modes from the fundamental core mode of a PCF, a coupling point or region is formed by using two methods. One is fusion splicing two pieces of a PCF with a small lateral offset, and the other is partially collapsing the air-holes in a single piece of PCF. By making another coupling point at a different location along the fiber, the proposed all-PCF interferometer is implemented. The spectral response of the interferometer is investigated mainly in terms of its wavelength spectrum. The spatial frequency of the spectrum was proportional to the physical length of the interferometer and the difference between the modal group indices of involved waveguide modes. For the splicing type interferometer, only a single spatial frequency component was dominantly observed, while the collapsing type was associated with several components at a time. By analyzing the spatial frequency spectrum of the wavelength spectrum, the modal group index differences of the PCF were obtained from to . As potential applications of the all-PCF interferometer, strain sensing is experimentally demonstrated and ultra-high temperature sensing is proposed.

Activation of the renin-angiotensin system within podocytes in diabetes

The autocrine and paracrine activation of the renin-angiotensin system (RAS) within cells of the kidney plays a role in the overall pathophysiology of the renal disease due to diabetes. In this study, we focus on components of the RAS in the podocyte as these cells are important in the pathogenesis of glomerulosclerosis and proteinuria. Immortalized mouse podocytes were exposed to media containing normal glucose (NG) or high glucose (HG) for in vitro studies. In vivo studies utilized kidney tissue obtained from rats treated for 3 months with streptozotocin to induce diabetes. Angiotensinogen (AGT) and the angiotensin II (AII) type 1 receptor mRNA and protein were significantly increased in the podocytes cultured under the high glucose conditions. Both angiotensins I and II levels were significantly higher in cell lysates and the conditioned media of cells grown in high glucose. There were no differences in renin activity, angiotensin-converting enzyme level, or AII type 2 receptor level. Glomerular AGT and AII type 1 receptor assessed by means of immunohistochemistry were increased in diabetic rats compared with the control rats. Other measured components of the RAS within the glomeruli were not different. We suggest that increased AGT, an attendant increase in AII and increased AII type 1 receptor in podocytes experiencing diabetic conditions play an important role in the pathogenesis of diabetic nephropathy.

Differences in corneal thickness and corneal endothelium related to duration in diabetes

PURPOSE

This study evaluated the differences of corneal thickness and corneal endothelial morphology in diabetes compared with age-matched, healthy control subjects; in addition, we tested for correlation according to the duration of diabetes.

METHODS

Ultrasound pachymetry and noncontact specular microscopy were performed on 200 patients with diabetes and 100 control subjects. We compared the values for diabetics and normal persons with ANACOVA to adjust for age. Moreover, we examined the correlation between the subject parameters and the duration of diabetes by using a partial correlation coefficient that controlled for age.

RESULTS

The diabetic subjects had thicker corneas, less cell density and hexagonality, and more irregular cell size of the corneal endothelium than did the controls (P < 0.05). Central corneal thickness and the coefficient of variation for cell size were significantly higher for diabetes of over 10 years' duration than for diabetes of under 10 years' duration (P < 0.05). The endothelial cell density and percentage of hexagonal cells were lower for diabetes of over 10 years' duration than for diabetes of under 10 years' (P > 0.05). Central corneal thickness was correlated with duration of diabetes (P < 0.05), but corneal endothelial morphology was not (P < 0.05).

CONCLUSIONS

Those patients with diabetic duration of over 10 years have more corneal morphological abnormalities, especially the coefficient of variation in cell size, compared with the normal subjects. The central corneal thickness was significantly correlated with diabetic duration after controlling for age.

The expression of RAGE and EN-RAGE in leprosy

BACKGROUND

Extracellular newly identified RAGE-binding protein (EN-RAGE) is a ligand of the receptor for advanced glycation endproducts (RAGE) and has been termed S100A12. The ligation of EN-RAGE with RAGE on the endothelium, mononuclear phagocytes and lymphocytes triggers cellular activation with the generation of the key proinflammatory mediators interleukin (IL)-1beta and tumour necrosis factor (TNF)-alpha.

OBJECTIVES

The aim of this study was to investigate the presence of RAGE and EN-RAGE, their spatial localization and their coexpression in leprosy lesions.

METHODS

Immunohistochemistry and confocal laser scanning microscopy were used to evaluate the expression of RAGE and EN-RAGE in leprosy. By enzyme-linked immunosorbent assay, RAGE and EN-RAGE were detected in the serum.

RESULTS

(1) In the multibacillary (MB) and paucibacillary (PB) groups, the level of RAGE production was significantly higher than in patients with atypical mycobacterial infection or sarcoidosis (P < 0.01). In the MB group, the production of RAGE was higher than in the PB group (P < 0.01), and it was higher in patients without the lepra reaction than in patients with the lepra reaction (P < 0.05). (2) In MB, PB and atypical mycobacterial infection, the level of EN-RAGE production was significantly higher than in sarcoidosis (P < 0.01). (3) In the confocal laser scanning microscopic examination, the RAGE and EN-RAGE proteins were detected in lepromatous leprosy. These proteins are spatially colocalized along the cell surface, which is in agreement with their receptor-ligand interaction. (4) A comparable amount of EN-RAGE was detected in the serum of the MB and PB groups. Patients with the reaction showed a higher level of EN-RAGE than patients without the reaction in leprosy.

CONCLUSIONS

Our data suggest that in leprosy, RAGE and EN-RAGE may be involved in the proinflammatory process rather than the antimycobacterial activity, especially during the lepra reaction. The blockade of the interaction of RAGE and EN-RAGE at the early stage of the inflammatory process may minimize the inflammatory response and consequent tissue damage or the sequelae of leprosy.

High-intensity focused ultrasound therapy for clinically localized prostate cancer

The efficacy of high-intensity focused ultrasound (HIFU) used for the treatment of localized prostate cancers has been demonstrated over the past decade. We present our early results after HIFU used as a single session in patients with clinically localized prostate cancer. A total of 58 patients were treated using the Ablatherm HIFU device with or without transurethral resection of the prostate (TURP). HIFU failure was defined as the presence of a cancer remnant on repeated biopsies or three consecutive increases in the prostate-specific antigen (PSA) >/=1.0 ng/ml. The mean follow-up was 14 months (range, 6-21 months). After HIFU treatment, 78% of patients had a decreased PSA level to <0.5 ng/ml within 3 months. The median value of the last PSA was 0.6 ng/ml and the median nadir PSA was 0.2 ng/ml. The success rates of HIFU were 85, 77 and 47% in low-, intermediate- and high-risk groups, respectively. The HIFU failure rate was closely associated with clinical stage, presence of cancer on TURP chips and nadir PSA on univariate analysis. However, the only significant predictor for HIFU failure was the nadir PSA value by multivariate Cox regression analysis. The operation-related complications were minimal. Although both the period and number of patients were limited to evaluate the clinical efficacy, HIFU appears to be a safe and effective treatment option in selected patients with prostate cancer.

The effects of curcumin on the invasiveness of prostate cancer in vitro and in vivo

Curcumin has become a focus of interest with regard to its antitumor effects in prostate cancer; however, the effects of this agent on invasion and metastasis remain less well understood. Matrix metalloproteinases (MMPs) are important prerequisite for tumor invasion and metastasis. In this study, we evaluated the effects of curcumin on prostate cancer cells (DU-145) invasion in both in vitro and in vivo. We utilized zymography and ELISA in order to determine the MMP-2 and MMP-9 activity. Matrigel invasion assay was performed to assess cellular invasion. We developed a xenograft model to examine tumorigenicity. Curcumin treatment resulted not only in a significant reduction in the expression of MMP-2 and MMP-9, but also effected the inhibition of invasive ability in vitro. Curcumin was shown to induce a marked reduction of tumor volume, MMP-2, and MMP-9 activity in the tumor-bearing site. The metastatic nodules in vivo were significantly fewer in the curcumin-treated group than untreated group. Curcumin appears to constitute a potential agent for the prevention of cancer progression, or at least of the initial phase of metastasis, in prostate cancer.