Pulse shortening mode-locked fiber laser by thickness and concentration product of carbon nanotube based saturable absorber

The dependence of thickness and concentration product (TCP) of single-wall carbon nanotubes saturable absorber (SWCNTs SA) on stabilizing and shortening pulsewidth in mode-locked fiber lasers (MLFLs) was investigated. We found that an optimized TCP for pulse energy and nonlinear self-phase modulation (SPM) enabled to determine the shorter pulsewidth and broader 3-dB spectral linewidth of the MLFLs. The shortest MLFL pulsewidth of 418 fs and broad spectral linewidth of 6 nm were obtained as the optimized TCP was 70.93 (μm•wt%), which was in good agreement with the area theorem prediction. This significant effect of TCP on pulse energy, SPM, pulsewidth, and spectral linewidth of MLFLs suggests that the TCP represents the total amount of SWCNTs in SA, which can be used as one of important and key parameters for characterizing the passive MLFL pulsewidth.

Clinical manifestations and prognostic factors in cancer patients with bacteremia due to extended-spectrum β-lactamase-producing Escherichia coli or Klebsiella pneumoniae

BACKGROUND

Clinical information about bacteremia due to extended-spectrum β-lactamase (ESBL)-producing pathogens in cancer patients was limited. The study was aimed to identify the clinical manifestations and risk factors for mortality in ESBL-producer bacteremia in cancer patients.

METHODS

A retrospective study of bacteremia caused by ESBL-producing Escherichia coli or Klebsiella pneumoniae in adults with cancer in National Cheng Kung University Hospital and National Taiwan University Hospital from July 2002 to August 2007 was conducted. Clinical characteristics, initial manifestations, and antimicrobial therapy were analyzed for their association with crude mortality at 14 days after bacteremia onset.

RESULTS

A total 113 episodes of bacteremia caused by E coli (59.3%), K pneumoniae (39.8%) or both (0.9%) were included. Patients with hematological malignancy were younger (55 ± 22 vs. 69 ± 14 years, p < 0.003) and had less co-morbidity, but were more likely to have neutropenia (73.1% vs. 4.6%, p < 0.001) than those with solid tumor. By the univariate analysis in 113 episodes of ESBL-producer bacteremia, several risk factors, including pneumonia or soft-tissue infection as the bacteremia source, initial manifestations with high Pitt bacteremia scores, shock, respiratory failure or severe sepsis, and inappropriate definitive therapy were associated with 14-day crude mortality. By multivariate analysis, only pneumonia [adjusted odds ratio (AOR), 5.2; 95% confident interval (CI), 1.3-21.0; p = 0.021], severe sepsis (AOR, 24.3; 95% CI, 5.6-105.0; p < 0.001), and inappropriate definitive therapy (AOR, 11.3; 95% CI, 1.7-72.8; p = 0.011) were independently associated with a fatal outcome.

CONCLUSION

The presence of neutropenia or underlying hematological malignancy in cancer patients with ESBL-producer bacteremia was not associated with an increase in the mortality rate. Appropriate definitive antimicrobial therapy will be beneficial in improving clinical outcome.

Collagen IV significantly enhances migration and transplantation of embryonic stem cells: involvement of α2β1 integrin-mediated actin remodeling

Embryonic stem (ES) cell transplantation represents a potential means for the treatment of degenerative diseases and injuries. As appropriate distribution of transplanted ES cells in the host tissue is critical for successful transplantation, the exploration of efficient strategies to enhance ES cell migration is warranted. In this study we investigated ES cell migration under the influence of various extracellular matrix (ECM) proteins, which have been shown to stimulate cell migration in various cell models with unclear effects on ES cells. Using two mouse ES (mES) cell lines, ESC 26GJ9012-8-2 and ES-D3 GL, to generate embryoid bodies (EBs), we examined the migration of differentiating cells from EBs that were delivered onto culture surfaces coated with or without collagen I, collagen IV, Matrigel, fibronectin, and laminin. Among these ECM proteins, collagen IV exhibited maximal migration enhancing effect. mES cells expressed α2 and β1 integrin subunits and the migration enhancing effect of collagen IV was prevented by RGD peptides as well as antibodies against α2 and β1 integrins, indicating that the enhancing effect of collagen IV on cell migration was mediated by α2β1 integrin. Furthermore, staining of actin cytoskeleton that links to integrins revealed well-developed stress fibers and long filopodia in mES cells cultured on collagen IV, and the actin-disrupting cytochalasin D abolished the collagen IV-enhanced cell migration. In addition, pretreatment of undifferentiated or differentiated mES cells with collagen IV resulted in improved engraftment and growth after transplantation into the subcutaneous tissue of nude mice. Finally, collagen IV pretreatment of osteogenically differentiated mES cells increased osteogenic differentiation-like tissue and decreased undifferentiation-like tissue in the grafts grown after transplantation. Our results demonstrated that collagen IV significantly enhanced the migration of differentiating ES cells through α2β1 integrin-mediated actin remodeling and could promote ES cell transplantation efficiency, which may be imperative to stem cell therapy.

Fatal tuberculous myositis in an immunocompromised adult with primary Sjögren's syndrome

Tuberculous myositis, which mimics rheumatic symptoms, is an extremely rare disease. Clinical ambiguity easily leads to misdiagnosis and delayed initial treatment. We present the case of a 55-year-old man who had primary Sjögren's syndrome and active cutaneous vasculitis treated with steroid and immunosuppressive drugs. He presented with a swollen, painful, hot left thigh. Although anti-tuberculosis medications were administered soon after a positive acid-fast stain of incisional muscular tissue, he died of rapidly progressive tuberculous myositis and multiorgan failure following 18 days of hospitalization. This case is presented to increase the awareness of this rare entity in clinical practice.

Somatic mutations of mitochondrial DNA in aging and cancer progression

Mitochondria are intracellular organelles responsible for generating ATP through respiration and oxidative phosphorylation (OXPHOS), producing reactive oxygen species, and initiating and executing apoptosis. Mitochondrial dysfunction has been observed to be an important hallmark of aging and cancer. Because mitochondrial DNA (mtDNA) is important in maintaining functionally competent organelles, accumulation of mtDNA mutations can affect energy production, oxidative stress, and cell survival, which may contribute to aging and/or carcinogenesis. This review outlines a variety of somatic mtDNA mutations identified in aging tissues and human cancers, as well as recent advances in understanding the causal role of mtDNA mutations in the aging process and cancer progression. Mitochondrial dysfunction elicited by somatic mutations in mtDNA could induce apoptosis in aging cells and some cancer cells with severe mtDNA mutations. In addition, it could activate mitochondria-to-nucleus retrograde signaling to modulate the expression of nuclear genes involved in a metabolic shift from OXPHOS to glycolysis, facilitate cells to adapt to altered environments and develop resistance to chemotherapeutic agents, or promote metastatic properties of cancer cells. These findings suggest that accumulation of somatic mtDNA mutations is not only an important contributor to human aging but also plays a critical role in cancer progression.

Changes in high-density lipoprotein and homeostasis model assessment of insulin resistance in medicated schizophrenic patients and healthy controls

BACKGROUND

This study intended to simultaneously investigate the relationships between high-density lipoprotein (HDL) and homeostasis model assessment of insulin resistance (HOMA-IR) in medicated schizophrenic patients vs healthy controls.

METHODS

During a 1-year period, we recruited 37 medicated schizophrenic patients and 30 healthy controls. Metabolic syndrome-related biomarkers including insulin and lipid profiles were enzymatically determined.

RESULTS

An analysis of covariance (ANCOVA) with BMI adjustment revealed that the patients had significantly lower HDL levels than the healthy controls (p = 0.017). ANCOVA with age adjustment revealed that the patients had significantly higher fasting insulin levels than the healthy controls (p = 0.034). In addition, in comparison with the healthy controls, the patients had higher mean serum levels of triglycerides, low-density lipoprotein, and total cholesterol as well as higher HOMA-IR values. However, there were no significant differences in any marker in the ANCOVA analysis after adjustment for age or BMI.

CONCLUSION

We found lower HDL and higher insulin levels in medicated schizophrenic patients than in healthy controls.

[Management of orthostatic hypotension in the elderly]

Orthostatic hypotension (OH) is a common health problem that affects 6% to 30% of the community-dwelling elderly. OH prevalence has been found to increase with age, influence the individual's quality of life, and be associated with increased rates of morbidity and mortality. Referencing evidence-based reports, the aim of the present article was to construct an OH management protocol for the elderly with OH. Causes of OH can be generally divided into recoverable and unrecoverable types. Recoverable types refer to OH conditions in which the patient's original health status can be restored following treatment. If such cannot be achieved, medical staffs must consider the possibility of an underlying unrecoverable factor. To treat unrecoverable OH, non-pharmacological intervention should be applied first. If such fails, then pharmacological interventions should be considered. Whether recoverable or unrecoverable, OH treatment should control acute health problems and follow general prevention principles. Nursing staffs play a crucial role in OH treatment. This proposed protocol may assist clinical nursing staffs to provide more appropriate elderly care.

Puerperal mastitis requiring hospitalization during a nine-year period

OBJECTIVES

To review the clinical and microbiologic features of isolates among patients with puerperal mastitis requiring hospitalization.

STUDY DESIGN

Between January 2000 and December 2008, postpartum patients who were hospitalized for mastitis were enrolled. The clinical characteristics, microbiologic results, management, and outcomes were reviewed.

RESULTS

One hundred twenty-seven cases were enrolled. Seventy-six patients (59.9%) underwent incision and drainage for abscess drainage, all of whom discontinued breastfeeding. Staphylococcus aureus and coagulase-negative staphylococci were the most common isolates. Among 81 isolates of S aureus, 52 (64.2%) were resistant to oxacillin. Patients undergoing incision and drainage were more likely to discontinue breastfeeding, had a longer duration of symptoms, a longer hospitalization, a higher platelet count and higher rates of infection caused by S aureus and oxacillin-resistant S aureus.

CONCLUSION

Oxacillin-resistant S aureus has emerged in patients with puerperal mastitis during the past decade, and often necessitates incision and drainage, which results in discontinuation of breastfeeding.

Gestational diabetes and central pontine myelinolysis with quadriplegia: a case report

Central pontine myelinolysis (CPM) has been reported in women with severe hyperemesis gravidarum-induced hyponatremia followed by rapid correction. Gestational diabetes with adipsia complicated by acute hypernatremia resulting in CPM has never been reported. Here is a case of a disabled female who presented with polydipsia, polyuria, seizures, fetal death in utero, hyperglycemia, and hyper-osmolar hypernatremia on her 31st gestational week. The dead fetus was delivered and the patient's plasma glucose and sodium were later stabilized. When the patient developed quadriplegia and respiratory failure 5 days later, brain magnetic resonance imaging showed central pontine and extra-pontine myelinolysis. Gestational diabetes complicated by hyper-osmolar crisis may cause fetal death and severe neurologic sequela. Early recognition and delivery of the fetus and placenta may improve the electrolyte and fluid imbalance.

Induction of insulin-producing cells derived from endometrial mesenchymal stem-like cells

Studies have demonstrated that mesenchymal stem-like cells can be isolated from endometrium. However, the potential of endometrial-derived stem cells to differentiate into insulin-positive cells and functionally secrete insulin remains undetermined. We isolated endometrial mesenchymal stem-like cells (EMSCs) from human endometrial tissue from six donors. The insulin-secreting function of EMSCs was further analyzed in vitro and in transplanted grafts in vivo. We successfully isolated EMSCs from human endometrium, and our results showed that EMSCs expressed high levels of stemness genes (Nanog, Oct-4, Nestin). Under specific induction conditions for 2 weeks, EMSCs formed three-dimensional spheroid bodies (SBs) and secreted C-peptide. The high insulin content of SB-EMSCs was confirmed by enzyme-linked immunosorbent assay, and glucose responsiveness was demonstrated by measuring glucose-dependent insulin secretion. Using cDNA microarrays, we found that the expression profiles of SB-EMSCs are related to those of islet tissues. Insulin and C-peptide production in response to glucose was significantly higher in SB-EMSCs than in undifferentiated EMSC controls. Furthermore, upon differentiation, SB-EMSCs displayed increased mRNA expression levels of NKx2.2, Glut2, insulin, glucagon, and somatostatin. Our results also showed that SB-EMSCs were more resistant to oxidative damage and oxidative damage-induced apoptosis than fibroblasts from the same patient. It is noteworthy that SB-EMSCs xenotransplanted into immunocompromised mice with streptozotocin-induced diabetes restored blood insulin levels to control values and greatly prolonged the survival of graft cells. These data suggest that EMSCs not only play a novel role in the differentiation of pancreatic progenitors, but also can functionally enhance insulin production to restore the regulation of blood glucose levels in an in vivo transplantation model.

Functional improvement of focal cerebral ischemia injury by subdural transplantation of induced pluripotent stem cells with fibrin glue

Ischemic stroke is the leading cause of disability in the world. Cell transplantation has emerged in various neurological diseases as a potential therapeutic approach in the postacute stroke phase. Recently, inducible pluripotent stem (iPS) cells showed potential for multilineage differentiation and provide a resource for stem cell-based therapies. However, whether iPS transplantation could improve the function of stroke-like model is still an open question. The aim of this study is to investigate the therapeutic effects of subdural transplantation of iPS mixed with fibrin glue (iPS-FG) on cerebral ischemic rats induced by middle cerebral artery occlusion (MCAO). We demonstrated an efficient method to differentiate iPS into astroglial-like and neuron-like cells which display functional electrophysiological properties. In vivo study firstly showed that the direct injection of iPS into damaged areas of rat cortex significantly decreased the infarct size and improved the motor function in rats with MCAO. Furthermore, we found that the subdural iPS-FG can also effectively reduce the total infarct volume and greatly improve the behavior of rats with MCAO to perform rotarod and grasping tasks. Importantly, analysis of cytokine expression in iPS-FG-treated ischemic brains revealed a significant reduction of pro-inflammatory cytokines and an increase of anti-inflammatory cytokines. Taken together, these results suggest that iPS cells could improve the motor function, reduce infarct size, attenuate inflammation cytokines, and mediate neuroprotection after ischemic stroke. Subdural iPS-FG could be considered as a more safe approach because this method can avoid iatrogenic injury to brain parenchyma and enhance recovering from stoke-induced impairment.

Alterations of kinetic characteristics in step up and over test in patients with anterior cruciate ligament deficiency

The purpose of this study is to investigate the alterations of kinetic characteristics in the step up/over test in patients with acute and chronic anterior cruciate ligament (ACL) deficiency. Twenty acute, twenty chronic ACL-deficient (ACLD) patients, and forty healthy controls participated in this study. The step up/over test was performed on a clinical force platform system to obtain the following variables: movement time, lift-up index and impact index. The percentages of the indexes from the stepping leg and time of step-up and swing- over were further calculated. These variables were examined statistically by using mixed repeated measure analysis of variance to reveal the differences between groups and between limbs. Smaller lift-up forces and longer swing-over time in both ACLD groups than those in the control group were found. One exception was the lift-up index in the affected side condition of the acute ACLD group, which was not significantly different from the controls. A reduced contribution to the impact index from the affected stepping leg was also found in the acute ACLD group. The acute ACLD group showed no significant change in their step-up strategy at the affected limbs, but they may have a poorer eccentric control of the affected knees on the step and thus put a larger portion of loading onto the unaffected landing leg. Our results indicated the lift-up index, swing-over time and load- distributing strategy at impact may be important parameters in monitoring functional recovery in patients with ACL deficiency. The detected alterations in these parameters could be used as a reference to design proper rehabilitation exercises for these patients. Key pointsThe lift-up index and the time of swing-over could be important parameters for indentifying functional impairments in patients with ACL deficiency.The differences between limbs were found only in the acute ACLD group with a larger lift-up index and smaller load-distribution at impact on the affected limb.The step up/over test on the clinical force platform system could be helpful in providing a reference to design proper rehabilitation exercise and to monitor the recovery of the functional ability in patients with ACL deficiency.

Fiber-optic particle plasmon resonance sensor for detection of interleukin-1β in synovial fluids

A facile and label-free biosensing method has been developed for determining an osteoarthritis concerned cytokine, interleukin-1β (IL-1β), in synovial fluids. The biosensing technique, fiber-optic particle plasmon resonance (FOPPR), is based on gold nanoparticles-modified optical fiber where the gold nanoparticle surface has been modified by a mixed self-assembled monolayer for further conjugation of anti-IL-1β antibody and minimization of nonspecific adsorption. Upon binding of IL-1β to anti-IL-1β on the gold nanoparticle surface, the absorbance of the gold nanoparticle layer on the optical fiber changes and the signal change is enhanced through multiple total internal reflections along the optical fiber. Results show that the detection of IL-1β in synovial fluid by this sensor agrees quantitatively with the clinically accepted enzyme-linked immunosorbent assay (ELISA) method but a much shorter analysis time is required (<10 min). The sensor response versus log concentration of IL-1β was linear (r=0.9947) over the concentration range of 0.050-10 ng/mL and a limit of detection (LOD) of 21 pg/mL (1.2 pM) was achieved. Such a LOD for IL-1β (17 kDa) represents a major advancement in the field of real-time monitoring of low molecular weight proteins in complex biological fluids.

Factors of early suicide after discharge: a national linkage study for suicide victims in Taiwan

Patients recently discharged from psychiatric inpatient care have a higher suicide rate. The study aimed to identify the characteristics associated with early suicide of those patients discharged from psychiatric wards in Taiwan. The results indicated that among 672 suicide victims who died within one year post-discharge from psychiatric wards in Taiwan between 2000 and 2004, diagnosis of schizophrenia, shorter disease duration, and co-morbidity with cancer were all significantly associated with suicide occurring within one month of discharge. Clinical diagnosis of psychiatric disorders, recent psychiatric diagnosis, and co-morbidity with severe physical illnesses should receive special monitoring for potential suicide after discharge.

Anti-N-methyl-D-aspartate receptor encephalitis in a young woman with an ovarian tumour

Anti-N-methyl-D-aspartate receptor encephalitis is characterised by psychiatric and neurological abnormalities and occurs in frequent association with ovarian teratoma. We report the first confirmed case of teratoma-associated anti-N-methyl-D-aspartate receptor encephalitis in Hong Kong in a young woman presenting with confusion and prominent dyskinesia, followed by a review of the current literature.

Treatment of hepatocellular carcinoma with adeno-associated virus encoding interleukin-15 superagonist

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, but effective therapies are still needed. The liver has been identified as an important immune organ and is heavily populated with various lymphocyte subsets known to play important roles in cancer immunosurveillance. We hypothesized that activation of hepatic lymphocytes by interleukin (IL)-15, a cytokine known for its ability to trigger proliferation and activation of natural killer (NK) cells, natural killer T cells, and memory CD8(+) T cells, might offer an alternative therapy for HCC. We employed hepatotropic adeno-associated virus serotype 8 (AAV8) to deliver an IL-15 superagonist (IL-15-IL-15RalphaS), consisting of IL-15 covalently linked to the N-terminal sushi domain of the IL-15 receptor alpha chain, to achieve local sustained cytokine expression in the liver environment. We observed that a single injection of AAV8 expressing IL-15-IL-15RalphaS, but not IL-15 alone, greatly expanded the number of hepatic mononuclear cells, mainly NK cells, for at least 21 days. AAV8/IL-15-IL-15RalphaS treatment generated potent antitumor activity in a liver metastatic murine HCC model (BNL cells), and significantly prolonged the survival time of treated animals. The antitumor effect depended mainly on NK cells, not on CD8(+) and CD4(+) T cells, because AAV8/IL-15-IL-15RalphaS treatment greatly enhanced the cytolytic activity of hepatic NK cells and depletion of NK cells abrogated the therapeutic effect. Importantly, no apparent liver toxicity was observed during AAV8/IL-15-IL-15RalphaS treatment. Together, our data demonstrate that AAV8-delivered IL-15-IL-15RalphaS provides an effective and safe therapy against metastatic HCC.

Resveratrol promotes osteogenic differentiation and protects against dexamethasone damage in murine induced pluripotent stem cells

Resveratrol is a natural polyphenol antioxidant that has been shown to facilitate osteogenic differentiation. A recent breakthrough has demonstrated that ectopic expression of four genes is sufficient to reprogram murine and human fibroblasts into induced pluripotent stem (iPS) cells. However, the roles of resveratrol in the differentiation and cytoprotection of iPS cells have never been studied. In this study, we showed that, in addition to cardiac cells, neuron-like cells, and adipocytes, mouse iPS cells could differentiate into osteocyte-like cells. Using atomic force microscopy that provided nanoscale resolution, we monitored mechanical properties of living iPS cells during osteogenic differentiation. The intensity of mineralization and stiffness in differentiating iPS significantly increased after 14 days of osteogenic induction. Furthermore, resveratrol was found to facilitate osteogenic differentiation in both iPS and embryonic stem cells, as shown by increased mineralization, up-regulation of osteogenic markers, and decreased elastic modulus. Dexamethasone-induced apoptosis in iPS cell-derived osteocyte-like cells was effectively prevented by pretreatment with resveratrol. Furthermore, resveratrol significantly increased manganese superoxide dismutase expression and intracellular glutathione level, thereby efficiently decreasing dexamethasone-induced reactive oxygen species (ROS) production and cytotoxicity. Transplantation experiments using iPS cell-derived osteocyte-like cells further demonstrated that oral intake of resveratrol could up-regulate osteopontin expression and inhibit teratoma formation in vivo. In sum, resveratrol can facilitate differentiation of iPS cells into osteocyte-like cells, protect these iPS cell-derived osteocyte-like cells from glucocorticoid-induced oxidative damage, and decrease tumorigenicity of iPS cells. These findings implicate roles of resveratrol and iPS cells in the stem cell therapy of orthopedic diseases.

Effects of structural intervention on increasing condom availability and reducing risky sexual behaviours in gay bathhouse attendees

The study purpose was to evaluate the effectiveness of a structural intervention in reducing unprotected sexual behaviours, increasing condom accessibility and their relationship to the prevalence of HIV infection and sexually transmitted infections (STIs) in gay bathhouse attendees. A quasi-experimental study with a non-equivalent control group for comparison was conducted at nine gay bathhouses in Taiwan from 2004 to 2006. A structural intervention designed to increase condom distribution and accessibility inside the bathhouses was implemented at one bathhouse in each city. Bathhouse attendees were invited to complete a questionnaire and to be screened for HIV infection and STIs. Of 632 study participants, 270 were surveyed six months after the intervention was conducted. At the time of follow-up after controlling for baseline data, patrons attending bathhouses for which intervention was performed were more likely to report accessing condoms inside bathhouses than those attending control bathhouses (92.6% versus 81.3%, P = 0.016), and condoms were more likely to be available at the reception desk of the bathhouse entrance (87.5% in intervention bathhouses versus 69.4% in control, P = 0.047). In a multivariate analysis adjusted for age, access to condoms inside bathhouses (adjusted odds ratio (AOR): 4.35; 95% confidence interval (CI): 1.48-12.78) and attendance at bathhouses with intervention (AOR: 2.07; 95% CI: 1.07-3.97) were independently associated with consistent condom use during anal intercourse. There were no significant differences in the prevalences of HIV infection and STIs at the six-month follow-up. Bathhouses with structural intervention were associated with consistent condom use during anal intercourse among bathhouse patrons. Our findings highlight the importance of extension of condom distribution inside the bathhouses to increase condom use among bathhouse patrons.