Nonlinear photoacoustic microscopy via a loss modulation technique: from detection to imaging

In order to achieve high-resolution deep-tissue imaging, multi-photon fluorescence microscopy and photoacoustic tomography had been proposed in the past two decades. However, combining the advantages of these two imaging systems to achieve optical-spatial resolution with an ultrasonic-penetration depth is still a field with challenges. In this paper, we investigate the detection of the two-photon photoacoustic ultrasound, and first demonstrate background-free two-photon photoacoustic imaging in a phantom sample. To generate the background-free two-photon photoacoustic signals, we used a high-repetition rate femtosecond laser to induce narrowband excitation. Combining a loss modulation technique, we successfully created a beating on the light intensity, which not only provides pure sinusoidal modulation, but also ensures the spectrum sensitivity and frequency selectivity. By using the lock-in detection, the power dependency experiment validates our methodology to frequency-select the source of the nonlinearity. This ensures our capability of measuring the background-free two-photon photoacoustic waves by detecting the 2nd order beating signal directly. Furthermore, by mixing the nanoparticles and fluorescence dyes as contrast agents, the two-photon photoacoustic signal was found to be enhanced and detected. In the end, we demonstrate subsurface two-photon photoacoustic bio-imaging based on the optical scanning mechanism inside phantom samples

In vivo sub-femtoliter resolution photoacoustic microscopy with higher frame rates

Microscopy based on non-fluorescent absorption dye staining is widely used in various fields of biomedicine for 400 years. Unlike its fluorescent counterpart, non-fluorescent absorption microscopy lacks proper methodologies to realize its in vivo applications with a sub-femtoliter 3D resolution. Regardless of the most advanced high-resolution photoacoustic microscopy, sub-femtoliter spatial resolution is still unattainable, and the imaging speed is relatively slow. In this paper, based on the two-photon photoacoustic mechanism, we demonstrated a in vivo label free laser-scanning photoacoustic imaging modality featuring high frame rates and sub-femtoliter 3D resolution simultaneously, which stands as a perfect solution to 3D high resolution non-fluorescent absorption microscopy. Furthermore, we first demonstrated in vivo label-free two-photon acoustic microscopy on the observation of non-fluorescent melanin distribution within mouse skin

Effect of Supplementation of Tanshinone IIA and Sodium Tanshinone IIA Sulfonate on the Anticancer Effect of Epirubicin: An In Vitro Study

Tanshinone IIA (Tan IIA) and sodium tanshinone IIA sulfonate (STS) were found to have protective effects on cardiomyocyte against adriamycin-induced damage and may be used clinically. It is unclear whether the supplementation of STS or Tan IIA would affect the anticancer activity of anthracycline. To evaluate the effect of Tan IIA or STS on the anticancer of epirubicin, the cell viability, apoptosis, Akt expression, and uptake of epirubicin after supplementation of Tan IIA or STS in the epirubicin-treated BT-20 cells were measured and compared. Tan IIA inhibited BT-20 cell growth and induced apoptosis in a time- and dose-dependent manner. When Tan IIA was used with epirubicin, an increase of BT-20 cells apoptosis was accompanied by the decreasing phosphorylation of Akt. STS had no effect on the cell viability of BT-20 cells. However, when used with epirubicin, STS decreased the epirubicin-induced cytotoxicity and apoptosis in BT-20 cells. The antagonistic effect of STS on epirubicin-induced cytotoxicity in BT-20 cells occurred concomitantly with the reduced epirubicin uptake and the increased phosphorylation of Akt. STS decreased the uptake of epirubicin in BT-20 cells and blocked epirubicin-induced apoptosis through activation of Akt

Persistence of Japanese Encephalitis Virus Is Associated with Abnormal Expression of the Nonstructural Protein NS1 in Host Cells

AbstractPersistent infection with Japanese encephalitis virus (JEV) was established in murine neuroblastoma N18 cells, and the persistency has been maintained in cell culture for over 6 months. From the persistently infected cells, a clone named C2-2 was selected and expanded to form a stable cell line. The vast majority of C2-2 cells showed viral protein staining by immunofluorescence and continuously produced low levels of virus (103to 104PFU/ml) without marked cytopathic effects or cyclic variations. In addition to the wild-type viral proteins, truncated forms of the viral nonstructural protein 1 (NS1) as well as its derivative NS1′ were produced in C2-2 cells. Both truncated NS1 and NS1′ contain deletions at their N-termini; however, the analyses by RT–PCR and direct sequencing of the viral RNA failed to detect any truncations or mutations within the NS1 region, suggesting that NS1 truncation was a result of a unique posttranslational proteolytic cleavage of NS1 in the persistently infected cells. Similar but not identical truncation of NS1 was also observed in two other persistently infected cell lines established in Vero and DBT (murine astrocytoma) cells. However, viruses released from C2-2 cells did not produce truncated NS1 upon infection of N18 cells, suggesting that NS1 truncations were the result of virus–cell interaction in persistently infected cells. These data indicate a strong association between abnormal NS1 expression and JEV persistency. A probable involvement of dysfunctional NS1 in the establishment and/or maintenance of JEV persistency in tissue culture is discussed

Highly reliable GIGA-sized synthetic human therapeutic antibody library construction

BackgroundMonoclonal antibodies (mAbs) and their derivatives are the fastest expanding category of pharmaceuticals. Efficient screening and generation of appropriate therapeutic human antibodies are important and urgent issues in the field of medicine. The successful in vitro biopanning method for antibody screening largely depends on the highly diverse, reliable and humanized CDR library. To rapidly obtain potent human antibodies, we designed and constructed a highly diverse synthetic human single-chain variable fragment (scFv) antibody library greater than a giga in size by phage display. Herein, the novel TIM-3-neutralizing antibodies with immunomodulatory functions derived from this library serve as an example to demonstrate the library’s potential for biomedical applications.MethodsThe library was designed with high stability scaffolds and six complementarity determining regions (CDRs) tailored to mimic human composition. The engineered antibody sequences were optimized for codon usage and subjected to synthesis. The six CDRs with variable length CDR-H3s were individually subjected to β-lactamase selection and then recombined for library construction. Five therapeutic target antigens were used for human antibody generation via phage library biopanning. TIM-3 antibody activity was verified by immunoactivity assays.ResultsWe have designed and constructed a highly diverse synthetic human scFv library named DSyn-1 (DCB Synthetic-1) containing 2.5 × 1010 phage clones. Three selected TIM-3-recognizing antibodies DCBT3-4, DCBT3-19, and DCBT3-22 showed significant inhibition activity by TIM-3 reporter assays at nanomolar ranges and binding affinities in sub-nanomolar ranges. Furthermore, clone DCBT3-22 was exceptionally superior with good physicochemical property and a purity of more than 98% without aggregation.ConclusionThe promising results illustrate not only the potential of the DSyn-1 library for biomedical research applications, but also the therapeutic potential of the three novel fully human TIM-3-neutralizing antibodies

Efficacy and toxicities of doxorubicin plus ifosfamide in the second-line treatment of uterine leiomyosarcoma

PurposeUterine leiomyosarcoma is a rare and aggressive tumor known for its drug resistance and metastatic potential. The standard first-line treatment typically involves anthracycline-based chemotherapy or a combination of gemcitabine and docetaxel; however, there is currently no established second-line treatment. Therefore, the aim of this study was to evaluate the efficacy and toxicity of doxorubicin plus ifosfamide as a potential second-line treatment for uterine leiomyosarcoma.Materials and methodsThis is a retrospective, single-center, single-arm study. We reviewed the tumor registry data from January 2010 to December 2022 and identified patients with uterine leiomyosarcoma who had previously received first-line salvage or adjuvant treatment involving gemcitabine and taxotere, and later experienced tumor recurrence. Patients who met these criteria were included in the study. The primary endpoint was the efficacy of doxorubicin and ifosfamide as a second-line treatment for uterine leiomyosarcoma, as measured by progression-free survival, 1-year overall survival, and response rate. The secondary endpoint was the adverse events associated with this regimen.ResultsFifty-two patients were diagnosed with uterine leiomyosarcoma during the study period, nine of whom were included in the data analysis. All patients had previously received gemcitabine-docetaxel as first-line adjuvant therapy, with a median progression-free survival period of 8.4 months. Doxorubicin-ifosfamide was administered as second-line treatment, with a median progression-free survival of 6.0 months (range: 2.7-79.9 months). The clinical benefit rate of the second-line treatment was 66.7%, with a median overall survival of 33.0 months, and a 1-year overall survival rate of 83.3%. Previous reports have shown that the median progression-free survival for second-line treatments using other regimens ranged from 1.4-5.6 months. The most common adverse event was myelosuppression, with five patients requiring granulocyte colony-stimulating factor and one patient requiring a blood transfusion. No patient discontinued treatment due to unmanageable adverse events.ConclusionUse of doxorubicin with ifosfamide may be a promising and reasonable second-line treatment with manageable adverse events for patients with uterine leiomyosarcoma

Improvement of Carbon Tetrachloride-Induced Acute Hepatic Failure by Transplantation of Induced Pluripotent Stem Cells without Reprogramming Factor c-Myc

The only curative treatment for hepatic failure is liver transplantation. Unfortunately, this treatment has several major limitations, as for example donor organ shortage. A previous report demonstrated that transplantation of induced pluripotent stem cells without reprogramming factor c-Myc (3-genes iPSCs) attenuates thioacetamide-induced hepatic failure with minimal incidence of tumorigenicity. In this study, we investigated whether 3-genes iPSC transplantation is capable of rescuing carbon tetrachloride (CCl4)-induced fulminant hepatic failure and hepatic encephalopathy in mice. Firstly, we demonstrated that 3-genes iPSCs possess the capacity to differentiate into hepatocyte-like cells (iPSC-Heps) that exhibit biological functions and express various hepatic specific markers. 3-genes iPSCs also exhibited several antioxidant enzymes that prevented CCl4-induced reactive oxygen species production and cell death. Intraperitoneal transplantation of either 3-genes iPSCs or 3-genes iPSC-Heps significantly reduced hepatic necrotic areas, improved hepatic functions, and survival rate in CCl4-treated mice. CCl4-induced hepatic encephalopathy was also improved by 3-genes iPSC transplantation. Hoechst staining confirmed the successful engraftment of both 3-genes iPSCs and 3-genes iPSC-Heps, indicating the homing properties of these cells. The most pronounced hepatoprotective effect of iPSCs appeared to originate from the highest antioxidant activity of 3-gene iPSCs among all transplanted cells. In summary, our findings demonstrated that 3-genes iPSCs serve as an available cell source for the treatment of an experimental model of acute liver diseases

Risk Factors for HIV-1 seroconversion among Taiwanese men visiting gay saunas who have sex with men

<p>Abstract</p> <p>Background</p> <p>Men having sex with men (MSM) accounts for 33.6% of all reported cases of HIV-1 infection in Taiwan. The aim of this study was to investigate the epidemiology of HIV-1 infection among MSM in gay saunas in Taiwan.</p> <p>Methods</p> <p>Patrons of 5 gay saunas were recruited for a weekly volunteer counseling and testing program from 2001 to 2005. Questionnaires were collected for a risk factor analysis. HIV-1 subtypes were determined using DNA sequencing and phylogenetic analyses.</p> <p>Results</p> <p>HIV-1 prevalence rates among MSM in gay saunas in 2001 through 2005 were 3.4%, 5.1%, 8.9%, 8.5%, and 8.3%, respectively. In total, 81 of 1, 093 (7.4%) MSM had HIV-1 infection. Fifty-two HIV-1 strains were genotyped, and all of them were subtype B. HIV-seropositive men were significantly younger than the seronegatives. Only 37.1% used condoms every time during sexual intercourse. A multivariate logistic regression analysis showed that the risk factors for HIV-1 were being uncircumcised (odds ratio (OR) = 2.19; 95% confidence interval (CI), 1.08~4.45); having sexual intercourse with at least 2 partners during each sauna visit (≥ 2 vs. ≤ 1, OR = 1.71; 95% CI, 1.02~2.89); and the role played during anal intercourse (versatile vs. an exclusively insertive role, OR = 2.76; 95% CI, 1.42~5.36).</p> <p>Conclusions</p> <p>Overall, 7.4% Taiwanese MSM participating in this study had HIV-1 subtype B infection. Uncircumcised, being versatile role during anal intercourse, and having sex with more than one person during each sauna visit were main risk factors for HIV-1 infection.</p