[Clinical observation of the intraocular distribution characteristics of indocyanine green after epiretinal membrane peeling using a fluorescence detection system developed in Python]

Objective: To utilize a Python-based fluorescence area detection system to observe and quantitatively analyze the intraocular distribution characteristics and metabolic patterns of Indocyanine Green (ICG) following epiretinal membrane peeling. Methods: A prospective case series study was conducted on patients with idiopathic epiretinal membrane undergoing vitrectomy at West China Hospital of Sichuan University from March 2019 to March 2021. ICG staining was applied during surgery for peeling the epiretinal membrane and internal limiting membrane. Patients were followed up at 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively, with assessments including best-corrected visual acuity, intraocular pressure, fundus photography, near-infrared fundus fluorescence imaging (NIR-FF), and optical coherence tomography (OCT). A Python-based ICG intraocular metabolism detection system was developed to measure the residual area of ICG fluorescence on NIR-FF, predict the ICG metabolic pattern equation, and correlate it with postoperative visual acuity and peripapillary retinal nerve fiber layer thickness. Results: A total of 64 patients (64 eyes) were included, with an average age of 64.6±8.4 years, including 25 males (39.1%) and 39 females (60.9%). Preoperative NIR-FF images showed no ICG strong fluorescence. At 1 week postoperatively, diffuse ICG strong fluorescence appeared in the posterior pole, and the internal limiting membrane removal area exhibited a ring-like weak fluorescence. Over time, ICG strong fluorescence was observed along the vascular arch and nerve fiber trajectory, gradually diminishing toward the optic disc, with residual ICG fluorescence still visible at the optic disc at 1 year. The Python-based ICG fluorescence area detection system effectively measured intraocular residual ICG area. A predictive equation for the 12-month residual ICG area was constructed through linear regression analysis (Residual ICG area=0.22 × Residual ICG area at 6 months, R2=16%, P=0.002). Except for a negative correlation between the ICG residual area at 1 month and postoperative visual acuity (P=0.017, r=-0.195), no correlation was found between intraocular ICG fluorescence residual area and postoperative visual acuity or peripapillary retinal nerve fiber layer thickness at other follow-up times (all P>0.05). Conclusions: In patients with idiopathic epiretinal membrane undergoing ICG staining for internal limiting membrane peeling, ICG exhibits characteristic metabolic processes in the eye, with strong fluorescence along the vascular arch and nerve fiber trajectory, gradually converging toward the optic disc over time. The Python-based ICG fluorescence area detection system provides a clear display of the intraocular distribution characteristics of ICG after epiretinal membrane peeling and serves as a tool for predicting the metabolic patterns of ICG in the eye.

MicroRNA-215 functions as a tumor suppressor and directly targets ZEB2 in human pancreatic cancer

It has been shown that microRNA-215 (miR-215) is dysregulated in several human malignancies, and this correlates with tumor progression. However, its expression and function in pancreatic cancer is still unclear. The aim of this study was to explore the effects of miR-215 on pancreatic cancer formation and progression. Using quantitative RT-PCR, we detected miR-215 expression in pancreatic cancer cell lines and primary tumor tissues. The association of miR-215 expression with clinicopathological factors and prognosis was also analyzed. We then observed the effects of miR-215 on the biological behavior of pancreatic cancer cells. Lastly, the potential regulatory function of miR-215 on ZEB2 expression was investigated. miR-215 expression levels were significantly downregulated in pancreatic cancer samples and cell lines. Decreased miR-215 expression was significantly associated with large tumor size, advanced TNM stage, lymph node metastasis, vessel invasion, and lower overall survival. Multivariate regression analysis corroborated that downregulation of miR-215 was an independent unfavorable prognostic factor. Overexpression of miR-215 inhibited pancreatic cancer cell proliferation, invasion, and migration; promoted cell apoptosis in vitro; and suppressed tumorigenicity in vivo. Further, ZEB2 was confirmed as a direct target of miR-215 by using a luciferase reporter assay. These findings indicate that miR-215 may act as a tumor suppressor in pancreatic cancer cells, and could serve as a novel therapeutic target for miR-based therapy.

Temporal variations of mobile carbohydrates in Abies fargesii at the upper tree limits

Low temperatures are associated high-altitude treelines, but the functional mechanism of treeline formation remains controversial. The relative contributions of carbon limitation (source activity) and growth limitation (sink activity) require more tests across taxa and regions. We examined temporal variations of mobile carbon supply in different tissues of Abies fargesii across treeline ecotones on north- and south-facing slopes of the Qinling Mountains, China. Non-structural carbohydrate (NSC) concentrations in tissues along the altitudinal gradient on both slopes changed significantly in the early and late growing season, but not in the mid-growing season, indicating the season-dependent carbon supply status. Late in the growing season on both slopes, trees at the upper limits had the highest NSC concentrations and total soluble sugars and lowest starch concentrations compared to trees at the lower elevations. NSC concentrations tended to increase in needles and branches throughout the growing season with increasing elevation on both slopes, but declined in roots and stems. NSC concentrations across sampling dates also indicated increases in needles and branches, and decreases in roots and stem with increasing elevation. Overall altitudinal trends of NSC in A. fargesii revealed no depletion of mobile carbon reserves at upper elevation limits, suggesting limitation of sink activity dominates tree life across treeline ecotones in both north- and south-facing slopes. Carbon reserves in storage tissues (especially roots) in the late growing season might also play an important role in winter survival and early growth in spring at upper elevations on both slopes, which define the uppermost limit of A. fargesii.

[Observation on the persistence period and transmission of residual microfilaremia with medium and higher density]

OBJECTIVE

To explore the persistence period of medium and higher density of microfilaremia and its role in the transmission of filariasis in areas with filariasis basically eradicated.

METHODS

The residual microfilaremia was followed up and the population were regularly examined by thick blood film assay. Culex quinquefaciatus were dissected to determine the natural infection rate and density of filarial larvae. The filarial antibody levels were detected by using IFAT.

RESULTS

Two cases with medium and higher density of microfilaremia were found to be microfilaremia positive for twelve years. The natural infection rate and density of filarial larvae in Culex quinquefasciatus dropped down year by year, one case of new microfilaremia was found in the sixteenth year.

CONCLUSION

The persistence period of residual medium and higher density of microfilaremia lasted for more than twelve years. The individual residual medium and higher density of microfilaremia cases still possess the potential for transmission of filariasis.

Immunosuppressive effects of dihydroetorphine, a potent narcotic analgesic, in dihydroetorphine-dependent mice

The immunomodulatory effects of dihydroetorphine were systematically investigated in subchronically treated mice. In a dose-dependent fashion, dihydroetorphine (total doses at 444.5, 889 and 1778 microg/kg) lowered the increase of body weight, decreased the weight of the spleen and thymus, weakened the delayed-type hypersensitivity, reduced the generation of antibody-forming cells, inhibited splenic lymphocyte proliferation induced by concanavalin A and lipopolysaccharide, suppressed the production of interleukin-2 in the supernatant of splenocytes induced by concanavalin A, and depleted the ratio of CD4+ and CD8+ subpopulations. Moreover, the physical dependence on dihydroetorphine was also evaluated to confirm that the immunosuppression was concomitant with the addiction to the drug. These results demonstrate that subchronic treatment with dihydroetorphine dose dependently suppresses both humoral and cell-mediated immune function, and that the immunosuppressive effects of dihydroetorphine are much more potent than those of morphine.

Involvement of mu-opioid receptors and alpha-adrenoceptors in the immunomodulatory effects of dihydroetorphine

The present study investigated the effects of acutely administered dihydroetorphine on mitogen-stimulated lymphocyte proliferation and lymphokine production in mice. These immune functions were significantly suppressed by dihydroetorphine at 24 microg/kg and 128 microg/kg in a dose-dependent fashion. This study further examined the involvement of micro-opioid receptors and alpha-adrenoceptors in the immunomodulatory effects of dihydroetorphine. The micro-opioid receptor antagonist, naloxone (4 mg/kg), and alpha-adrenoceptor antagonist, phentolamine (10 mg/kg), but not the beta-adrenoceptor antagonist, propranolol (10 mg/kg), effectively blocked dihydroetorphine-induced suppression of splenic lymphocyte proliferation and lymphokine production. These results demonstrate that dihydroetorphine has significant immunosuppressive effects in mice and the mechanisms of these effects may lie in its interactions with opioid receptors and adrenergic pathways.

[Polarographic determination of titanium in natural water]

Titanium has a very sensitive catalytic polarographic wave in the system of cupferon-hexamine-sodium sulfate at pH 6.0-6.4. The catalytic current was proportional to the content of titanium. High blank of the reagents could be improved by extraction with the system of cupferron-chloroform. For determination, samples were filtered with quantitative filter paper, but it was not necessary for drinking water samples. The filtration was acidified with HCl to 0.5% (V/V) and heated in a boiling water bath for 30 min, 5 ml sample was sufficed to most analyses. The detection limit was 0.12 microgram/L. The coefficient of variation was 8% for 6 determinations at 0.2 microgram/L. Three levels of titanium were spiked to one sample, and it was found that the recoveries were 96-101%. The proposed method was applied to rain water, well-head water, well water, tap water and river water. The content of titanium of most samples was less than 2 micrograms/L.