The Association between Diabetic Retinopathy and Macular Degeneration: A Nationwide Population-Based Study

OBJECTIVE

Age-related macular degeneration (AMD), particularly its exudative form, is a primary cause of vision impairment in older adults. As diabetes becomes increasingly prevalent in aging, it is crucial to explore the potential relationship between diabetic retinopathy (DR) and AMD. This study aimed to assess the risk of developing overall, non-exudative, and exudative AMD in individuals with DR compared to those without retinopathy (non-DR) based on a nationwide population study in Taiwan.

METHODS

A retrospective cohort study was conducted using the Taiwan National Health Insurance Database (NHIRD) (2000-2013). A total of 3413 patients were placed in the study group (DR) and 13,652 in the control group (non-DR) for analysis. Kaplan-Meier analysis and the Cox proportional hazards model were used to calculate the hazard ratios (HRs) and adjusted hazard ratios (aHRs) for the development of AMD, adjusting for confounding factors, such as age, sex, and comorbid conditions.

RESULTS

Kaplan-Meier survival analysis indicated a significantly higher cumulative incidence of AMD in the DR group compared to the non-DR group (log-rank test, p < 0.001). Adjusted analyses revealed that individuals with DR faced a greater risk of overall AMD, with an aHR of 3.50 (95% CI = 3.10-3.95). For senile (unspecified) AMD, the aHR was 3.45 (95% CI = 3.04-3.92); for non-exudative senile AMD, it was 2.92 (95% CI = 2.08-4.09); and for exudative AMD, the aHR was 3.92 (95% CI = 2.51-6.14).

CONCLUSION

DR is a significant risk factor for both overall, senile, exudative, and non-exudative AMD, even after adjusting for demographic and comorbid conditions. DR patients tend to have a higher prevalence of vascular comorbidities; however, our findings indicate that the ocular pathologies inherent to DR might have a more significant impact on the progression to AMD. Early detection and appropriate treatment of AMD is critically important among DR patients.

Association between amiodarone use and risk of cataract: a population-based active-comparator study

BACKGROUND

Despite previous concerns about ocular side effects related to amiodarone, the relationship between amiodarone and cataract remains uncertain. Therefore, this study aimed to assess the potential association between amiodarone use and the subsequent risk of cataract, taking into account potential confounders.

METHODS

This population-based, active comparator-controlled cohort study utilized the data from the Taiwan National Health Insurance program and involved adults over 40 years old between 2001 and 2013. We analyzed 12 055 new amiodarone users and contrasted them with a propafenone user cohort. The primary outcome was the incidence of cataract. Inverse-probability treatment-weighting (IPTW) was further used to eliminate the potential confounding effects, and Cox proportional-hazard regression analyses were performed to calculate the risk of cataract. Serial subgroup analyses were also performed.

RESULTS

In the main analysis, amiodarone users did not exhibit a significant causal relationship in both full cohort [adjusted hazard ratio (aHR): 0.994, 95% confidence interval (CI): 0.913-1.082] and IPTW cohort (IPTW-aHR 0.977, 95% CI: 0.900-1.060). Furthermore, it is important to highlight a significantly reduced risk of cataract among patients with heart failure (IPTW-aHR 0.708, 95% CI: 0.554-0.905) and during the 2-year follow-up period (IPTW-aHR 0.889, 95% CI: 0.794-0.996), implying potential advantages linked to the use of amiodarone.

CONCLUSIONS

The study found no increased risk of cataract with amiodarone, one of the most frequently used antiarrhythmic medications, compared to the use of propafenone. Future research is recommended to explore potential mechanisms and their implications for clinical practice.

Influenza vaccination is associated with lower risk of renal cell carcinoma among chronic kidney disease patients: a population-based cohort study

Background

Chronic kidney disease (CKD) patients possess a higher risk for renal cell carcinoma (RCC) possibly because of related underlying inflammation and immune dysregulation. In the current population-based cohort study, we evaluate the effects of influenza vaccination on RCC among CKD patients.

Methods

We analysed the vaccinated and unvaccinated CKD patients (≥55 years of age) identified from the Taiwan National Health Insurance Database. Propensity score matching was used to reduce the selection bias. Subgroup analyses based on comorbid conditions, dialysis status and vaccinated dosages were also conducted.

Results

The incidence of RCC decreased significantly in the vaccinated compared with unvaccinated group {unadjusted hazard ratio [HR] 0.50 [95% confidence interval (CI) 0.31-0.81], P < .01; adjusted HR 0.46 [95% CI 0.28-0.75], P < .01}. Such protective effects of influenza vaccination were noted significantly among those ≥75 years of age [unadjusted HR 0.29 (95% CI 0.12-0.74), P < .01; adjusted HR 0.22 (95% CI 0.08-0.58), P < .01]. A reverse association was noted between the total number of vaccinations and RCC events in both unadjusted and adjusted models. The Kaplan-Meier estimates of the RCC events showed significantly higher free survival rates in the vaccinated as compared with the unvaccinated patients (logrank P = .005).

Conclusion

This population-based cohort study found a significant inverse relationship between influenza vaccination and the risk of RCC in CKD patients and the protective effects were more prominent in patients >75 years of age. A possible relation exists between the total number of vaccinations and RCC events. Future randomized clinical and basic studies will be needed to prove these findings and underlying pathophysiological mechanisms.

Ultra-thin Ag/Si heterojunction hot-carrier photovoltaic conversion Schottky devices for harvesting solar energy at wavelength above 1.1 µm

Traditional silicon solar cells can only absorb the solar spectrum at wavelengths below 1.1 μm. Here we proposed a breakthrough in harvesting solar energy below Si bandgap through conversion of hot carriers generated in the metal into a current using an energy barrier at the metal-semiconductor junction. Under appropriate conditions, the photo-excited hot carriers can quickly pass through the energy barrier and lead to photocurrent, maximizing the use of excitation energy and reducing waste heat consumption. Compared with conventional silicon solar cells, hot-carrier photovoltaic conversion Schottky device has better absorption and conversion efficiency for an infrared regime above 1.1 μm, expands the absorption wavelength range of silicon-based solar cells, makes more effective use of the entire solar spectrum, and further improves the photovoltaic performance of metal-silicon interface components by controlling the evaporation rate, deposition thickness, and annealing temperature of the metal layer. Finally, the conversion efficiency 3.316% is achieved under the infrared regime with a wavelength of more than 1100 nm and an irradiance of 13.85 mW/cm².

[Attention should be paid to glaucoma following pediatric cataract surgery]

Glaucoma following cataract surgery is one of the common complications after pediatric cataract surgery, and it is the main cause of "second blindness" in children. Since this atypical disease is difficult to diagnose and evaluate, it has been gradually paid more attention by clinicians. There are still some controversies and challenges related to the characteristics of the disease, diagnostic criteria, and treatment options. This article discusses the definition, diagnostic criteria, related risk factors, treatment strategies, follow-up, and prognoses of glaucoma following cataract surgery. Establishment of a diagnosis and treatment system can better improve the visual rehabilitation of pediatric cataract children.

Risk of Dry Eye Syndrome in Patients with Orbital Fracture: A Nationwide Population-Based Cohort Study

This study aimed to investigate whether orbital fracture increases the risk of dry eye syndrome (DES) and identified the profile of prognostic factors. We studied a cohort from the Taiwan National Health Insurance Research Database (NHIRD). Overall, 46,179 and 184,716 participants were enrolled in the study and control groups, respectively. Each patient in the case group was age- and gender-matched to four individuals without orbital fracture that served as the control group. Cox proportional hazards analysis regression was used to estimate the risks of incident DES. During the follow-up period, the case group was more likely to develop incident DES (0.17%) than the control group (0.11%) (p = 0.001). Multivariate Cox regression analysis demonstrated that the case group had a 4.917-fold increased risk of DES compared to the controls. In the stratified age group, orbital fracture had the highest impact on patients aged 18–29 years. Furthermore, patients with orbital roof fracture have a greater risk of developing DES. Regardless of whether having received surgery or not, the patients with orbital fracture have higher risks of DES. Our study demonstrated that orbital fracture increases the risk of developing subsequent DES. Early recognition by thorough examinations with raised awareness in the clinical setting could preserve visual function and prevent further complications.

Author Correction: Relationship between body mass index and renal function deterioration among the Taiwanese chronic kidney disease population

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Very Low-Density Lipoproteins of Metabolic Syndrome Modulates STIM1, Suppresses Store-Operated Calcium Entry, and Deranges Myofilament Proteins in Atrial Myocytes

Individuals with metabolic syndrome (MetS) are at high risk for atrial myopathy and atrial fibrillation. Very low-density lipoproteins (VLDLs) of MetS (MetS-VLDLs) are cytotoxic to atrial myocytes in vivo and in vitro. The calcineurin-nuclear factor of activated T-cells (NFAT) pathway, which is regulated by stromal interaction molecule 1 (STIM1)/ calcium release-activated calcium channel protein 1 (Orai1)-mediated store-operated Ca²⁺ entry (SOCE), is a pivotal mediator of adaptive cardiac hypertrophy. We hypothesized that MetS-VLDLs could affect SOCE and the calcineurin-NFAT pathway. Normal-VLDL and MetS-VLDL samples were isolated from the peripheral blood of healthy volunteers and individuals with MetS. VLDLs were applied to HL-1 atrial myocytes for 18 h and were also injected into wild-type C57BL/6 male mouse tails three times per week for six weeks. After the sarcoplasmic reticulum (SR) Ca²⁺ store was depleted, SOCE was triggered upon reperfusion with 1.8 mM of Ca²⁺. SOCE was attenuated by MetS-VLDLs, along with reduced transcriptional and membranous expression of STIM1 (P = 0.025), and enhanced modification of O-GlcNAcylation on STIM1 protein, while Orai1 was unaltered. The nuclear translocation and activity of calcineurin were both reduced (P < 0.05), along with the alteration of myofilament proteins in atrial tissues. These changes were absent in normal-VLDL-treated cells. Our results demonstrated that MetS-VLDLs suppressed SOCE by modulating STIM1 at the transcriptional, translational, and post-translational levels, resulting in the inhibition of the calcineurin-NFAT pathway, which resulted in the alteration of myofilament protein expression and sarcomere derangement in atrial tissues. These findings may help explain atrial myopathy in MetS. We suggest a therapeutic target on VLDLs to prevent atrial fibrillation, especially for individuals with MetS.

Diabetic Retinopathy as a Risk Factor for Chronic Kidney Disease Progression: A Multicenter Case⁻Control Study in Taiwan

It has rarely been studied whether the presence and severity of diabetic retinopathy (DR) could influence the renal disease progression among all chronic kidney disease (CKD) diabetic patients. This study investigates the characteristics of diabetic patients, with different stages of chronic kidney disease (CKD), according to the occurrence of diabetic retinopathy and determines the influence of retinopathy in the deterioration of renal function. We conduct a multicenter, longitudinal cohort study based on the Epidemiology and Risk Factors Surveillance of the CKD project (2008–2013) and the National Health Insurance Research Database (NHIRD) (2001–2013). A total of 4050 diabetic patients with CKD, 20–85 years of age, from 14 hospitals and the community are included in this study. As compared to CKD patients without DR, CKD patients with DR have a lower baseline estimated glomerular filtration rate (eGFR) (39.17 ± 30.36 mL/min per 1.73 m² vs. 54.38 ± 33.67 mL/min per 1.73 m² ); poorer glycemic control (higher glycated hemoglobin (HbA1c) 7.85 ± 4.97 vs. 7.29 ± 4.02, p < 0.01); higher proteinuria (urine protein-to-creatinine ratio (UPCR )1.94 ± 2.96 g/dL vs. 0.91 ± 2.11 g/dL, p < 0.01); more anemia (Hb 11.22 ± 2.43 g/dL vs. 12.39 ± 3.85 g/dL, p < 0.01), and more hypoalbuminemia (3.88 ± 0.95 g/dL vs. 4.16 ± 1.74 g/dL, p < 0.01). Later stage (stage 3b–5) CKD patients with DR had significantly higher CKD progression compared with patients without DR (OR (odds ratio) 1.66 (1.36–2.02)). Patients with proliferative DR had significantly higher CKD progression events compared to patients with non-proliferative DR (OR 2.18 (1.71–2.78)). The presence and severity of DR is a risk factor for CKD progression among our Taiwanese CKD patients with diabetes. Prevention and early detection of DR are important and DR should be routinely screened as early as possible among diabetic CKD patients.

Simultaneous Electrocardiography Recording and Invasive Blood Pressure Measurement in Rats

For studies related to cardiovascular physiology or pathophysiology, blood pressure (BP) and electrocardiography are basic observational parameters. Research focusing on cardiovascular disease models, potential cardiovascular therapeutic targets or pharmaceutical agents requires assessment of systemic arterial pressure and heart rhythm changes. In situations where radio telemetry systems are not available or affordable, the technique of femoral artery cannulation is an alternative way to obtain intra-arterial pressure waveform recordings and systemic BP measurements. This technique is economical and can be performed with standard equipment in animal facilities. However, invasive arterial pressure recording requires cannulation of small arteries, which can be a challenging surgical skill. Here, we present step-by-step protocols for femoral artery cannulation procedures. Key procedures include the calibration of the data acquisition system, tissue dissection and femoral artery cannulation, and setup of the arterial cannulation system for pressure recording. Surface electrocardiography recording procedures are also included. We also present examples of BP recordings from normotensive and hypertensive rats. This protocol allows reliable direct recordings of systemic BP with simultaneous electrocardiography.

Optical coherence tomography angiography in unilateral multifocal choroiditis and panuveitis: A case report

RATIONALE

Optical coherence tomography angiography (OCT-A) has the advantage to visualize the microvascular structure of the retina in vivo and was utilized clinically in various neovascular retinal diseases. The OCT-A has also been used to examine the lesion in multifocal choroiditis and panuveitis (MCP). This study aimed to describe a case of MCP and present the disease process of a punched-out lesion in the chorioretina with neovascular activity using OCT-A.

PATIENTS CONCERNS

A 32-year-old female Caucasian patient presented with a 2-week history of progressive blurred vision in her right eye with photophobia and a diminished temporal visual field. On presentation, her best corrected visual acuity was 6/60 in the right eye with a prominent anterior uveitis seen under slit lamp examination.

DIAGNOSES

Dilated fundus examination of the right eye showed vitritis and multiple, punched-out yellowish-white lesions over the peripheral retina. Additional multimodal imaging (MMI) were done including fluorescein angiography (FA), indocyanine green angiography (ICGA) and fundus autofluorescence (FAF), which all revealed characteristic findings of MCP. In general, the diagnosis of unilateral MCP was made. Furthermore, one of the punched-out lesions in the right eye was particularly selected and examined under OCT and OCT-A, which revealed a subretinal elevated lesion with high flow signal under OCT-A.

INTERVENTIONS

Treatment with oral prednisolone at 30 mg daily with topical prednisolone acetate 1% every 2 hours were prescribed, which were gradually tapered down within a 2-month course.

OUTCOMES

The patient's best corrected visual acuity of the right eye returned to 6/6 at 2 months after the diagnosis. The flow signal in the OCT-A study of the punched-out lesion had also resolved after steroid treatment.

LESSONS

The MCP is an uncommon uveitis with multiple inflammatory chorioretinal lesions. Using multimodal imaging technique, physicians can better differentiate these lesions for diagnosis and for further monitoring. Our results demonstrated that these chorioretinal lesions in MCP may display neovascular activities that might not be seen easily using conventional FA or ICGA study. With OCT-A, ophthalmologists could identify and monitor subtle choroidal neovascularization (CNV) changes over these punched-out lesions.

Impact of hypoxic and mesopic environments on visual acuity, contrast sensitivity and accommodation in subjects with LASIK surgery and aircrew candidate

BACKGROUND

The safety of Laser-assisted in situ keratomileusis (LASIK) in aircrew was unclear, in addition, LASIK was not yet approved for aircrew of Taiwan Air Force. This study was aimed to evaluate visual performance in LASIK eyes in hypoxic and twilight environment.

METHODS

48 myopic eyes of 24 subjects enrolled in this study were divided into LASIK group and control group. Subjects were exposed in hypoxic (15% O₂) and mesopic (3 cd/m²) environment. Visual performance was evaluated using the Early Treatment of Diabetic Retinopathy Study (ETDRS) visual chart, and Functional Acuity Contrast Test (FACT) before and after the expirement. Physiological parameters of all subjects were measured and recorded throughout the experiment.

RESULTS

There was no significant difference of the two groups regarding their age, height, weight, and BMI. There is significant difference of preoperative spherical refractive error between the two groups. The results of physiological parameters were similar between two groups. Under normoxic conditions, there were no significant difference regarding distant vision in photopic and mesopic environments, so as for near vision. As a whole, the contrast sensitivity of the LASIK group were lowered than that of the control group about 35%, under whether normoxic or hypoxic conditions; photopic or mesopic circumstances. Under normoxic conditions, the measured accommodation of the LASIK group were 21% lowered than that of the control group and 31% lowered under hypoxic circumstances.

CONCLUSION

There was no significant difference of visual acuity between the two groups regarding hypoxic and mesopic environment, but reduced contrast sensitivity was significant in LASIK group as compared to those of the control group. Accommodation was significantly lowered in LASIK group, compared with control group, in hypoxic environment. Whether postoperative visual performance after LASIK in aircrew during flying duty is safe might need further investigation.

Application of lateral tarsoconjunctival flap to correct ocular complications of Madelung's disease: A case report and literature review

RATIONALE

Madelung's disease is a specific type of benign symmetric lipomatosis, which is characterized by overgrowing fat distributed at the neck and shoulder. This excessive fat accumulation may occur in different regions, including vital organs, such as the larynx, trachea, or the orbits. Surgery is usually performed to correct the esthetic or functional concern of the affected area. There are only few case reports mentioned about the orbital involvement of this disease. This study aimed to describe a case of Madelung's disease with ocular complications and the successful treatment using tarsoconjunctival flap.

PATIENT CONCERNS

A 90-year-old obese male presented with decreased visual acuity accompanied with severe band form punctate epithelial erosions and ciliary injections in both eyes. Exophthalmos and ectropion of the lower eyelids were observed.

DIAGNOSES

Orbital computed tomography revealed a rare entity of Madelung's disease with significant massive deposits of lipomas located symmetrically around the orbit and neck region.

INTERVENTIONS

Bilateral lateral tarsoconjunctival flaps with lateral tarsal strip procedures were performed to correct the lower eyelid ectropion-related exposure keratopathy.

OUTCOMES

The patient obtained improved visual acuity, intact and clear corneal surfaces, and perfect lower eyelid positions over both eyes.

LESSONS

Madelung's disease is a rare condition. There are few reports to describe its ocular complications, due to lipoma overgrowing in the orbit. We shared our successful experience to correct ocular complications using tarsoconjunctival flap technique.

[Clinical characteristics and surgical effect observation of congenital aniridia combined with cataract]

Objective: To analyze the clinical manifestations, surgical approaches and postoperative prognosis for the cases of congenital aniridia combined with cataract. Methods: In this retrospective case series, 26 patients diagnosed with congenital aniridia combined with cataract were collected from Zhongshan Ophthalmic Center from February 2002 to August 2016. The Clinical data were collected to analyze the clinical features, surgical approaches and postoperative prognosis. T-test was used for statistical analysis. Results: Twenty-six bilateral congenital aniridia patients were included in the case series, with 50% male cases. The average age for the first visit was (8.72±8.06) years old. Hereditary patients constitutes 30.8% (8/26) of the total number. The proportions for bilateral and unilateral cataracts were 88.5% (23/26) and 11.5% (3/26) respectively, and 49 eyes suffering from both congenital aniridia and cataract were therefore included in the final analysis. The most common morphology cataract subtypes were lamellar cataract (24.5%, 12/49), posterior subcapsular cataract (22.4%, 11/49), and total cataract (18.4%,9/49). The observed ocular comorbidities included nystagmus (36.7%, 18/49), vitreous opacity (28.6%, 14/49), foveal hypoplasia (20.4%, 10/49), ametropia (12.2%, 6/49), exotropia (12.2%, 6/49), congenital glaucoma (12.2%, 6/49), esotropia (4.1%, 2/49), congenital ptosis (4.1%, 2/49), lens ectopia (4.1%, 2/49), scleral staphyloma (2.0%, 1/49) and pigmentary degeneration of retina (2.0%, 1/49). 30.6% (15/49) eyes were performed the cataract extraction surgery. The percentage of postoperative best corrected visual acuity (BCVA) for ≥0.1 and ≥0.3 were 93.3% (14/15) and 20.0% (3/15) respectively. Evaluated ocular pressure (33.3%, 5/15), severe posterior capsular opacification (PCO) (13.3%, 2/15) and choroidal hemorrhage combined with choroidal detachment (6.7%, 1/15) were detected as the postoperative complications. Followed by cataract extraction, 80.0% (12/15) eyes were sequentially performed the intraocular lens implantation, while, 20.0% (3/12) eyes remained aphakia due to ocular comorbidities. Conclusions: Congenital aniridia combined with cataract are rare diseases, calling for the precious retrospective researches. This disorder tended to affect both eyes and occurred hereditary. The clinical courses of the cases presented progressive features. Ocular comorbidities were the crucial factors to influence the surgical approaches and postoperative prognosis. (Chin J Ophthalmol, 2017, 53: 821-827).

Very-Low-Density Lipoprotein of Metabolic Syndrome Modulates Gap Junctions and Slows Cardiac Conduction

Very-low-density lipoproteins (VLDL) is a hallmark of metabolic syndrome (MetS) and each manifestation of MetS is related to atrial fibrillation (AF) risks. Slowed atrial conduction is a mechanism of AF in MetS. We hypothesized that VLDL can modulate and reduce atrial gap junctions. VLDLs were separated from normal (Normal-VLDL) and MetS (MetS-VLDL) individuals. VLDLs (15 µg/g) and equivalent volumes of saline (CTL) were injected respectively to C57BL/6 mice for 6 weeks. Electrocardiograms demonstrated that MetS-VLDL induced prolongation of P wave (P = 0.041), PR intervals (P = 0.014), QRS duration and QTc interval (both P = 0.003), but Normal-VLDL did not. Optical mapping of perfused hearts confirmed slowed conduction on atria and ventricles of MetS-VLDL mice. Slowed cardiac conduction was associated with significant atrial and ventricular remodeling, along with systolic dysfunction and comparable intra-cardiac fibrosis. MetS-VLDL induced downregulation of Cx40 and Cx43 at transcriptional, translational and tissue levels, and it also enhanced O-GlcNAcylation of Cx40 and Cx43. Protein structure analyses predicted O-GlcNAcylation at serine 18 of Cx40 and Cx43 which may impair stability of gap junctions. In conclusion, MetS-VLDL modulates gap junctions and delays both atrial and ventricular conduction. VLDL may contribute to the pathophysiology of atrial fibrillation and ventricular arrhythmias in MetS.

Effect of microgravity on the mesenchymal stem cell characteristics of limbal fibroblasts

BACKGROUND

Mesenchymal stem cells (MSCs) are important for regenerative medicine. Limbal fibroblasts (LFs), present in the corneal limbus, have been shown to possess MSC characteristics, and can differentiate into other cell types. The current study sought to investigate the effect of microgravity on the proliferation and differentiation of LFs, and identify culture conditions to obtain a high proportion of LFs possessing MSC characteristics.

METHODS

A rotary cell culture system was used to generate microgravity. Cellular proliferation and MSC marker (CD14, CD45, CD90, CD105, and SSEA4) expression were evaluated by WST-1 test and flow cytometry, respectively. Differentiation of LFs into adipocytes, osteocytes, and chondrocytes was examined. The effects of LF-conditioned medium on limbal stem cell differentiation were assessed.

RESULTS

The cellular proliferation rates under microgravity were significantly lower than those under normal gravity (0.44 vs. 0.18 at 24 h, and 0.70 vs. 0.44 at 48 h, both P ≤ 0.004). Higher proportions of cells expressed CD90 (95.33% vs 81.69%), CD105 (95.32% vs 87.96%), and SSEA4 (68.26% vs 26.13%) under microgravity than under normal gravity. The differentiation potential of LFs was more prominent under microgravity. The LF-conditioned medium attenuated the differentiation of limbal corneal epithelial stem cells.

CONCLUSION

Under microgravity, LFs showed a higher proportion of MSC characteristics and were easily induced into different linage cells. Culture in a microgravity environment may allow harvesting a greater number of MSC-like LFs for stem cell therapy in ocular surface reconstruction.

Atorvastatin from target screening attenuates endothelial cell tube formation and migration by regulating urokinase receptor-related signaling pathway and F/G actin

BACKGROUND

Angiogenesis and cytoskeletal transformation are common denominators of many pathological developments. The relationship between angiogenesis, urokinase plasminogen activator receptor (uPAR) signaling pathway, and cytoskeletal transformation is still unknown. In this study, a pGL3-uPAR promoter reporter system combined with Bio-Plex mRNA analysis was established for discovering uPAR modulators to analyze this interconnection.

METHODS

After screening a set of clinically used drugs, atorvastatin (Ator) was found to significantly affect uPAR expression and its ideal dose, 1 μM, was determined for cell study. Mouse endothelial cell (mEC) models, including tube formation for angiogenesis and wound healing assay for migration, were employed to test the effects on angiogenesis and cytoskeletal transformation with (Group Ator) and without (Group C) the treatment of Ator.

RESULTS

The mEC tube formation and migration was significantly decreased in Group Ator. Regarding cytoskeleton changes, the ratio of F/G actin by Western blotting and the assembly of F-actin (lamellipodia) by immunofluorescence were attenuated. Furthermore, uPAR and all uPAR-related factors, including integrin α5β3, phosphorylated-focal adhesion kinase, and Rac, revealed a significant reduction when compared with Group C.

CONCLUSION

We conclude that close regulatory machinery spans angiogenesis, uPAR signaling, and cytoskeletal transformation, and that uPAR modulator Ator can decrease the reorganization of actin cytoskeleton, which may lead to a new approach in angiogenesis.

Deferasirox has strong anti-leukemia activity but may antagonize theanti-leukemia effect of doxorubicin

Deferasirox (DFX), in addition to its iron-chelation property, has marked anti-proliferative effects on cancer cells. However, the activity and mechanism by which DFX inhibits acute myeloid leukemia (AML) cells remain to be elucidated. Furthermore, the anti-leukemia effect of combining DFX with currently recommended agents doxorubicin (DOX) and cytosine arabinoside (Ara-C) has not been studied. In this study, we show that DFX significantly reduces the viability of three AML cell lines, HL60, THP1, and WEHI3 and two primary leukemic cells harvested from AML patients. DFX induces cell cycle arrest at G1 phase and apoptosis and inhibits phosphorylation of ERK. We also showed that DFX antagonizes the anti-leukemic effect of DOX. On the contrary, combining DFX with Ara-C created a synergistic effect. Our study confirms the anti-leukemia activity of DFX and provides important information on how to select a partner drug for DFX for the treatment of AML in future clinical trials.

Aryl hydrocarbon receptor-ligand axis mediates pulmonary fibroblast migration and differentiation through increased arachidonic acid metabolism

Pulmonary fibroblast migration and differentiation are critical events in fibrogenesis; meanwhile, fibrosis characterizes the pathology of many respiratory diseases. The role of aryl hydrocarbon receptor (AhR), a unique cellular chemical sensor, has been suggested in tissue fibrosis, but the mechanisms through which the AhR-ligand axis influences the fibrotic process remain undefined. In this study, the potential impact of the AhR-ligand axis on pulmonary fibroblast migration and differentiation was analyzed using human primary lung fibroblasts HFL-1 and CCL-202 cells. Boyden chamber-based cell migration assay showed that activated AhR in HFL-1cells significantly enhanced cell migration in response to 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), and a known AhR antagonist, CH223191, inhibited its migratory activity. Furthermore, the calcium mobilization and subsequent upregulated expression of arachidonic acid metabolizing enzymes, including cyclooxygenase2 (COX-2) and 5-lipoxygenase (5-LOX), were observed in TCDD-treated HFL-1 cells, concomitant with elevated levels of prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) secretion. Also, significantly increased expression of α-smooth muscle actin α-SMA), a fibroblast differentiation marker, was also noted in TCDD-treated HFL-1 cells (p<0.05), resulting in a dynamic change in cytoskeleton protein levels and an increase in the nuclear translocation of the myocardin-related transcription factor. Moreover, the enhanced levels of α-SMA expression and fibroblast migration induced by TCDD, PGE2 and LTB4 were abrogated by selective inhibitors for COX-2 and 5-LOX. Knockdown of AhR by siRNA completely diminished intracellular calcium uptake and reduced α-SMA protein verified by promoter-reporter assays and chromatin immunoprecipitation. Taken together, our results suggested the importance of the AhR-ligand axis in fibroblast migration and differentiation through its capacity in enhancing arachidonic acid metabolism.

Solid-state, ambient-operation thermally activated delayed fluorescence from flexible, non-toxic gold-nanocluster thin films: towards the development of biocompatible light-emitting devices

Luminescent gold nanoclusters (AuNCs) with good biocompatibility have gained much attention in bio-photonics. In addition, they also exhibit a unique photo-physical property, namely thermally activated delayed fluorescence (TADF), by which both singlet and triplet excitons can be harvested. The combination of their non-toxic material property and unique TADF behavior makes AuNCs biocompatible nano-emitters for bio-related light-emitting devices. Unfortunately, the TADF emission is quenched when colloidal AuNCs are transferred to solid states under ambient environment. Here, a facile, low-cost and effective method was used to generate efficient and stable TADF emissions from solid AuNCs under ambient environment using polyvinyl alcohol as a solid matrix. To unravel the underlying mechanism, temperature-dependent static and transient photoluminescence measurements were performed and we found that two factors are crucial for solid TADF emission: small energy splitting between singlet and triplet states and the stabilization of the triplet states. Solid TADF films were also deposited on the flexible plastic substrate with patterned structures, thus mitigating the waveguide-mode losses. In addition, we also demonstrated that warm white light can be generated based on a co-doped single emissive layer, consisting of non-toxic, solution-processed TADF AuNCs and fluorescent carbon dots under UV excitation.

A Facile and Low-Cost Method to Enhance the Internal Quantum Yield and External Light-Extraction Efficiency for Flexible Light-Emitting Carbon-Dot Films

Solution-processed, non-toxic carbon dots (CDs) have attracted much attention due to their unique photoluminescence (PL) properties. They are promising emissive layers for flexible light-emitting devices. To this end, the CDs in pristine aqueous solutions need to be transferred to form solid-state thin films without sacrificing their original PL characteristics. Unfortunately, solid-state PL quenching induced by extra non-radiative (NR) energy transfer among CDs would significantly hinder their practical applications in optoelectronics. Here, a facile, low-cost and effective method has been utilized to fabricate high-performance CD/polymer light-emitting flexible films with submicron-structured patterns. The patterned polymers can serve as a solid matrix to disperse and passivate CDs, thus achieving high internal quantum yields of 61%. In addition, they can act as an out-coupler to mitigate the waveguide-mode losses, approximately doubling the external light-extraction efficiency. Such CD/polymer composites also exhibit good photo-stability, and thus can be used as eco-friendly, low-cost phosphors for solid-state lighting.

VLDL from Metabolic Syndrome Individuals Enhanced Lipid Accumulation in Atria with Association of Susceptibility to Atrial Fibrillation

Metabolic syndrome (MetS) represents a cluster of metabolic derangements. Dyslipidemia is an important factor in MetS and is related to atrial fibrillation (AF). We hypothesized that very low density lipoproteins (VLDL) in MetS (MetS-VLDL) may induce atrial dilatation and vulnerability to AF. VLDL was therefore separated from normal (normal-VLDL) and MetS individuals. Wild type C57BL/6 male mice were divided into control, normal-VLDL (nVLDL), and MetS-VLDL (msVLDL) groups. VLDL (15 µg/g) and equivalent volumes of saline were injected via tail vein three times a week for six consecutive weeks. Cardiac chamber size and function were measured by echocardiography. MetS-VLDL significantly caused left atrial dilation (control, n = 10, 1.64 ± 0.23 mm; nVLDL, n = 7, 1.84 ± 0.13 mm; msVLDL, n = 10, 2.18 ± 0.24 mm; p < 0.0001) at week 6, associated with decreased ejection fraction (control, n = 10, 62.5% ± 7.7%, vs. msVLDL, n = 10, 52.9% ± 9.6%; p < 0.05). Isoproterenol-challenge experiment resulted in AF in young msVLDL mice. Unprovoked AF occurred only in elderly msVLDL mice. Immunohistochemistry showed excess lipid accumulation and apoptosis in msVLDL mice atria. These findings suggest a pivotal role of VLDL in AF pathogenesis for MetS individuals.

Rapamycin Promotes Mouse 4T1 Tumor Metastasis that Can Be Reversed by a Dendritic Cell-Based Vaccine

Suppression of tumor metastasis is a key strategy for successful cancer interventions. Previous studies indicated that rapamycin (sirolimus) may promote tumor regression activity or enhance immune response against tumor targets. However, rapamycin also exhibits immunosuppressant effects and is hence used clinically as an organ transplantation drug. We hypothesized that the immunosuppressive activities of rapamycin might also negatively mediate host immunity, resulting in promotion of tumor metastasis. In this study, the effects of rapamycin and phytochemical shikonin were investigated in vitro and in vivo in a 4T1 mouse mammary tumor model through quantitative assessment of immunogenic cell death (ICD), autophagy, tumor growth and metastasis. Tumor-bearing mice were immunized with test vaccines to monitor their effect on tumor metastasis. We found that intraperitoneal (ip) administration of rapamycin after a tumor-resection surgery drastically increased the metastatic activity of 4T1 tumors. Possible correlation of this finding to human cancers was suggested by epidemiological analysis of data from Taiwan’s National Health Insurance Research Database (NHIRD). Since our previous studies showed that modified tumor cell lysate (TCL)-pulsed, dendritic cell (DC)-based cancer vaccines can effectively suppress metastasis in mouse tumor models, we assessed whether such vaccines may help offset this rapamycin-promoted metastasis. We observed that shikonin efficiently induced ICD of 4T1 cells in culture, and DC vaccines pulsed with shikonin-treated TCL (SK-TCL-DC) significantly suppressed rapamycin-enhanced metastasis and Treg cell expansion in test mice. In conclusion, rapamycin treatment in mice (and perhaps in humans) promotes metastasis and the effect may be offset by treatment with a DC-based cancer vaccine.

Shikonin-enhanced cell immunogenicity of tumor vaccine is mediated by the differential effects of DAMP components

BACKGROUND

The tumor cell lysate-pulsed, dendritic cell (DC)-based cancer vaccine approaches are being actively evaluated for application to cancer immunotherapy, hopefully at a personalized medicine base. There is apparently an emerging technical problem however, the lack of highly efficacious potency in activation of patient's DCs for T-cell priming and the associated process for presenting tumor immunogenicity.

METHODS

One strategy to address this is to consider the manipulation of the tumor immunogenic cells death (ICD) complex ex-vivo for maximal activation of DC efficacy. In our previous study we showed that phytochemical shikonin (SK) can drastically enhance ICD activity in mouse tumor cells treated ex-vivo, and the resultant tumor cell lysate (TCL) can effectively augment such SK-TCL pulsed DC vaccine activity in vivo in anti-tumor activities. In this study, we investigated the specifics and the multi-functional effects of various damaged associated molecular pattern (DAMP) components of the ICD complex for their participation, roles and potential cross talks in activating DCs, as measured by five different functional assays.

RESULTS

Among three DAMPs tested, HSP70 and CRT mediate a key role in SK-TCL-induced DC immunity for both CD4(+) and CD8(+) T cell proliferations in vitro. HSP70 is the most important component, followed by CRT, then HMGB1 in facilitating DC immunity on suppressing metastasis of mouse 4 T1 mammary tumors and prolonging survival in test mice. Only HSP70, but not CRT or HMGB1, is effective for the suppression of both granulocytic and monocytic MDSC populations in vivo. Both HSP70 and HMGB1, but not CRT, are essential in activating the expression of three key ICD molecules-associated receptors on test DCs. Each of the three test ICD proteins can exhibit a distinguishable pattern in stimulating the expression of four key chemokines in test DCs.

CONCLUSION

Our findings on the differential roles or effect of various ICD components in activating vaccinated DCs may help formulate new strategies for future cancer vaccine designs.

Influenza A plasma and serum virus antibody detection comparison in dogs using blocking enzyme-linked immunosorbent assay

Background and Aim:

The influenza A virus (IAV) is an important zoonotic pathogen with infections also reported in dogs. IAV infections can be detected through the presence of antibodies using the enzyme-linked immunosorbent assay (ELISA). Serum is the only standard sample source; however, there is no information on the availability of other sample sources for IAV antibody detection in dogs. Compared with serum, plasma is more widely employed in most animal hospitals. The object of this study is to investigate whether plasma collected in ethylenediaminetetraacetic acid (EDTA) tubes (EDTA plasma) or heparin tubes (heparin plasma) could be used in the ELISA protocol instead of serum for IAV antibody detection in dogs.

Materials and Methods:

Totally, 82 matched EDTA plasma and serum sample pairs and 79 matched heparin plasma and serum sample pairs were employed using blocking enzyme-linked immunosorbent assay (bELISA). The agreement and correlation between the plasma (EDTA or heparin plasma) and serum were assessed using the agreement index kappa (kD) calculation and Pearson correlation coefficient, respectively.

Results:

The agreement index kD of EDTA plasma and serum was 1.0, and that of heparin plasma and serum was 0.85. The Pearson correlation coefficient of EDTA plasma and serum was 0.87 (p<0.01), and that of heparin plasma and serum was 0.82 (p<0.01).

Conclusion:

The results proved that plasma, especially EDTA plasma, could be substituted for serum in the bELISA test. This might greatly expand the clinical applicability of IAV antibody detection in dogs.

Pitfalls of CT for deep neck abscess imaging assessment: a retrospective review of 162 cases

OBJECTIVES

To investigate the diagnostic value of contrast-enhanced computed tomography (CT) for the prediction of deep neck abscesses in different deep neck spaces and to evaluate the false-positive results.

METHOD

We retrospectively analysed the clinical charts, CT examinations, surgical findings, bacteriology, pathological examinations and complications of hospitalised patients with a diagnosis of deep neck abscess from 2004 to 2010. The positive predictive values (PPV) for the prediction of abscesses by CT scan in different deep neck spaces were calculated individually on the basis of surgical findings.

RESULTS

A total of 162 patients were included in this study. All patients received both intravenous antibiotics and surgical drainage. The parapharyngeal space was the most commonly involved space. The overall PPV for the prediction of deep neck abscess with contrast-enhanced CT was 79.6%. The PPV was 91.3% when more than one deep neck space was involved but only 50.0% in patients with isolated retropharyngeal abscesses. In the false-positive group, cellulitis was the most common final result, followed by cystic degeneration of cervical metastases. Five specimens taken intra-operatively revealed malignancy and four of these were not infected.

CONCLUSIONS

There are some limitations affecting the differentiation of abscesses and cellulitis, particularly in the retropharyngeal space. A central necrotic cervical metastatic lymph node may sometimes also mimic a simple pyogenic deep neck abscess on both clinical pictures and CT images. Routine biopsy of the tissue must be performed during surgical drainage.

Destabilization of CARP mRNAs by aloe-emodin contributes to caspase-8-mediated p53-independent apoptosis of human carcinoma cells

Using short hairpin RNA against p53, transient ectopic expression of wild-type p53 or mutant p53 (R248W or R175H), and a p53- and p21-dependent luciferase reporter assay, we demonstrated that growth arrest and apoptosis of FaDu (human pharyngeal squamous cell carcinoma), Hep3B (hepatoma), and MG-63 (osteosarcoma) cells induced by aloe-emodin (AE) are p53-independent. Co-immunoprecipitation and small interfering RNA (siRNA) studies demonstrated that AE caused S-phase cell cycle arrest by inducing the formation of cyclin A-Cdk2-p21 complexes through extracellular signal-regulated kinase (ERK) activation. Ectopic expression of Bcl-X(L) and siRNA-mediated Bax attenuation significantly inhibited apoptosis induced by AE. Cyclosporin A or the caspase-8 inhibitor Z-IETD-FMK blocked AE-induced loss of mitochondrial membrane potential and prevented increases in reactive oxygen species and Ca(++). Z-IETD-FMK inhibited AE-induced apoptosis, Bax expression, Bid cleavage, translocation of tBid to mitochondria, ERK phosphorylation, caspase-9 activation, and the release of cytochrome c, apoptosis-inducing factor (AIF), and endonuclease G from mitochondria. The stability of the mRNAs encoding caspase-8 and -10-associated RING proteins (CARPs) 1 and 2 was affected by AE, whereas CARP1 or 2 overexpression inhibited caspase-8 activation and apoptosis induced by AE. Collectively, our data indicate AE induces caspase-8-mediated activation of mitochondrial death pathways by decreasing the stability of CARP mRNAs in a p53-independent manner.

Energy transfer from InGaN quantum wells to Au nanoclusters via optical waveguiding

We present the first observation of resonance energy transfer from InGaN quantum wells to Au nanoclusters via optical waveguiding. Steady-state and time-resolved photoluminescence measurements provide conclusive evidence of resonance energy transfer and obtain an optimum transfer efficiency of ~72%. A set of rate equations is successfully used to model the kinetics of resonance energy transfer.

Artificial neural network analysis for reliability prediction of regional runoff utilization

Many factors in the reliability analysis of planning the regional rainwater utilization tank capacity need to be considered. Based on the historical daily rainfall data, the following four analyzing procedures will be conducted: the regional daily rainfall frequency, the amount of runoff, the water continuity, and the reliability. Thereafter, the suggested designed storage capacity can be obtained according to the conditions with the demand and supply reliability. By using the output data, two different types of artificial neural network models are used to build up small area rainfall-runoff supply systems for the simulation of reliability and the prediction model. They are also used for the testing of stability and learning speed assessment. Based on the result of this research, the radial basis function neural network (RBFNN) model, using the Gaussian function that has a similar trend as the nature as basic function, has better stability than using the back-propagation neural network (BPNN) model. Despite the fact that RBFNN was more reliable than BPNN, it still made a conservative estimate for the actual monitoring data. The error rate of RBFNN was still higher than the correction of BPNN 4-3-1-1. This should have significant benefit in the future application of the instantaneous prediction or the development of related intelligent instantaneous control equipment.

Thermal modeling and performance analysis of a thermoacoustic refrigerator

A heat-driven thermoacoustic refrigerator has been designed and tested. A detailed thermal model of the device is presented. Energy balances within the system are discussed using external, heat exchanger, and stack control volumes in order to clarify the relationships of work and heat fluxes below and above onset. Thermal modeling is discussed as a tool for performance analysis as well as for determining system heat losses and finding input heat flows required by a thermoacoustic code. A method of using the control volume balance equations to find stack work and device efficiencies is presented. Experimental measurements are compared to DELTAE thermoacoustic modeling predictions. Modeling results show that viscous losses within the system have a significant impact on the device performance as well as on the ability of DELTAE to accurately predict performance. Modeling has led to an understanding of system performance and highlighted loss sources that are areas for improvement in a redesign.

Dissipation of epoxiconazole in the paddy field under subtropical conditions of Taiwan

The environmental fate and distribution of fungicide epoxiconazole were studied by a rice paddy field model ecosystem. One week before the head-sprouting stage, rice plant was treated separately once with OPUS (tradename of epoxiconazole) 12% SC 2.1 kg ha(-1) and 1.4 kg ha(-1), respectively. Soil, water and rice plant were sampled seven days intervals nine times after application. The bioconcentration factor of epoxiconazole on mosquito fish in the ecosystem was also determined, based on the amounts of epoxiconazole content both in fish and water. This was initiated one day after the fungicide treatment, and continued for four days. In addition, the residue of epoxiconazole in rice grains was analyzed after harvest. After harvest, both planted water spinach (Ipomoea aquatica Forsk) and edible amaranth (Amaranthus mangostanüs L.) were analyzed. The results showed that epoxiconazole degraded in the local environment under the experimental conditions described. The degradation equations were in accordance with the first order kinetics. The DT50 of soil, field water and rice plant were 20-69 days, 11-20 days and 14-39 days, respectively. The bioconcentration factors of epoxiconazole on mosquito fish were 12.9 and 10.6 from 2.1 kg ha(-1) and 1.4 kg ha(-1) treatment, respectively. Residues of epoxiconazole in both rice and harvest vegetables were non-detectable. This indicates that epoxiconazole applied to rice at the recommended rates and application frequencies will not accumulate on rice grain and successive cropping vegetables.

Hantavirus infection in Taiwan: the experience of a geographically unique area

Hantaviruses are rodent-borne viruses, and they, mainly the Hantaan (HTN) serotype, are the causative agents of a group of febrile nephropathies known as "hemorrhagic fever with renal syndrome (HFRS). " Despite the fact that HFRS is frequently reported in China, with an annual incidence of 50,000-100,000 cases, one puzzling observation that no local case of HFRS has been confirmed in Taiwan has yet to be explained. We hypothesized that the hantavirus strain prevailing in Taiwan mainly belongs to the mild strain, the Seoul (SEO) strain, and the absence of severe disease was related to the absence of HTN. To test these hypotheses, this epidemiologic study was performed, including a seroprevalence survey and phylogenetic analysis on hantavirus isolated from the rodent population trapped in major seaports, rural, and mountainous areas of Taiwan. This study also included rodents and viruses from two isolated islands, Kinmen and Matzu, which are geographically adjacent to the east coast of mainland China. There were a total of 5,461 rodents of 16 species captured, and R. norvegicus was the most common species, with an antibody prevalence much higher in international seaports (20%) than in rural regions (approximately 5%) and intermediate in some domestic seaports. By reverse transcriptase polymerase chain reaction (RT-PCR), 33.9% of the seropositive R. norvegicus were found to have amplifiable hantavirus sequences in their lung tissues, and subsequent phylogenetic analyses indicated that almost all hantavirus in Taiwan was most closely related to the prototype SEO strain, and no HTN strain was recovered from any rodent species indigenous to Taiwan. The seroprevalence of SEO infection in R. norvegicus on Kinmen and Matzu was also different from that in southern provinces of China but closely resembled that in seaports in Taiwan, and the SEO identified was genetically linked to Taiwanese SEO strains. These results substantiate our hypotheses, and suggest that the epidemiology of hantavirus infection in Taiwan are different from that in China, where the HTN and SEO strains and HFRS concurrently prevail.

Changes in volatile flavor components of guava juice with high-pressure treatment and heat processing and during storage

The changes in volatile flavor components of guava juice during pressure processing (25 degrees C, 600 MPa, 15 min), heat processing (95 degrees C, 5 min), and storage at 4 and 25 degrees C were evaluated by purge and trap/gas chromatography/mass spectrometry. Esters were the major volatile fraction in guava juice, and alcohols were the second. Pressure processing could maintain the original flavor distribution of the juice. Heat processing (95 degrees C, 5 min) caused decreases in the majority of flavor components in the juice when compared with freshly extracted juice. High-pressure treatment at 600 MPa for 15 min can effectively sterilize microbes but partially inactivate enzymes of guava juice; therefore, volatile components in pressure-treated juice gradually changed during storage periods. Pressure-treated guava juice showed increases in methanol, ethanol, and 2-ethylfuran with decreases in the other components during storage period. Nevertheless, the volatile distribution of 600 MPa treated guava juice was similar to that of freshly extracted juice when stored at 4 degrees C for 30 days.

High pressure and heat treatments effects on pectic substances in guava juice

Effects of high pressure treatment on changes in pectic substances in guava juice were investigated and compared with those of heat treated samples. The viscosity and turbidity of guava juice pressurized at 6000 atm and 25 degrees C for 10 min increased slightly, whereas the viscosity of juice heated at 95 degrees C for 5 min decreased from 362 to 285 cps while turbidity increased from 0.87 to 1.15 (OD 600 nm). There were no apparent changes in water soluble, oxalate soluble and alkali soluble pectins in the pressurized juice. However, heat treated juice exhibited a decrease in its water and alkali soluble pectins and a slight increase in oxalate soluble pectin. The DEAE-cellulose profiles of pectic substances in guava juice were apparently unchanged after high pressure treatment while they were markedly changed by heat treatment, due to coagulation or degradation. During thermal processing, the degradation of pectin in guava juice caused a decrease in viscosity while the coagulation of pectin resulted in an increase in turbidity and cloud content. High pressure treatment showed no marked changes in pectic substances and cloud content in guava juice and maintained its natural viscous properties.

Quantitative analysis of mRNA encoding MUC1, MUC2, and MUC5AC genes: a correlation between specific mucin gene expression and sialomucin expression in non-small cell lung cancer

The expression of mucins is important for tumor invasiveness and metastasis. In our previous report (Am. J. Respir. Crit. Care Med. 1997; 155:1419-1427), non-small cell lung cancers bearing sialomucin expression tended to relapse earlier than those without sialomucin. However, it remained unclear whether the expression of sialomucin in lung cancer is caused by an abnormal glycosylation process or by the expression of a specific mucin gene product. To address this problem, we established a modified quantitative competitive polymerase chain reaction (QC-PCR) analysis. RNA internal standards of MUC1, MUC2, and MUC5AC non-tandem repeat sequences were constructed, and known copy numbers of mucin RNA internal standards were introduced into reverse transcription-polymerase chain reactions (RT-PCR) for each mucin gene in order to compete with native mucin gene RNA during the reaction. The RNA of Gbeta-like gene (a housekeeping gene) was used as internal control for the RNA analysis. Twenty-five lung cancer tissues (13 adenocarcinomas and 12 squamous cell carcinomas) were used for analysis. Mann-Whitney rank sum test was applied to compare the expression amounts of different mucin genes in tissues. The results revealed that adenocarcinoma expressed higher amounts of MUC5AC gene than did squamous cell carcinoma (P = 0.03). The expression amount of MUC5AC correlated positively with the expression status of sialomucin (P = 0.012). Further studies are anticipated to elucidate the underlying mechanism contributing to this phenomenon.

99Tcm-HMPAO-labelled white blood cell scans to detect acute appendicitis in older patients with an atypical clinical presentation

Forty-nine patients (age > 50 years) with an acute abdomen and suspected appendicitis, but with atypical findings, were included in the study. After the intravenous injection of 99Tcm-hexamethylpropylene amine oxime (99Tcm-HMPAO) labelled white blood cells (WBCs), serial anterior images of the abdomen and pelvis were obtained after 30, 60, 120 and 240 min. Any abnormal localization of WBC accumulation in the right lower quadrant of the abdomen equal to or greater than bone marrow activity was considered positive. Twenty-five patients had positive WBC scans, all of whom underwent laparotomy. Twenty-three of these patients were shown to have appendicitis; the other 2 did not. The other 24 patients had a negative WBC scan, 2 of whom underwent laparotomy and were shown to have appendicitis; the other 22 patients did not undergo surgery and showed no evidence of appendicitis during follow-up. The overall sensitivity, specificity, accuracy, positive and negative predictive values of WBC scans for diagnosing appendicitis were as follows: 92.0%, 91.7%, 91.8%, 92.0% and 91.7% respectively. In conclusion, 99Tcm-HMPAO-labelled WBC scans provide a rapid and highly accurate method for diagnosing appendicitis in older patients with equivocal clinical findings.

Tc-99m HMPAO-labeled WBC scans to detect appendicitis in women

Fifty female patients with acute abdomen and suspected appendicitis but atypical findings were included in this study. After intravenous injection of Tc-99m HMPAO-labeled WBCs, serial anterior abdominal/pelvic images at 30, 60, 120, and 240 minutes were obtained by a gamma camera. Any abnormal localization of WBC accumulation in the right lower quadrant of the abdomen with equal to or greater than bone marrow activity was considered as a positive scan. Thirty patients had positive WBC scans and underwent laparotomy, 28 had proven appendicitis, and 2 were not related to appendicitis. Twenty patients had negative WBC scans, 2 patients underwent laparotomy and were proved to have appendicitis. The remaining 18 patients did not undergo surgery and revealed no evidence of appendicitis after follow-up. The overall sensitivity, specificity, accuracy, and positive and negative predictive values for WBC scans to diagnose appendicitis is 93.3%, 90.0%, 92.0%, 93.3%, and 90.0%, respectively. In conclusion, Tc-99m HMPAO-labeled WBC imaging provides a rapid and highly accurate method for diagnosis of appendicitis in female patients with equivocal clinical examinations.

Supine lung clearance of Tc-99m DTPA and HMPAO aerosols

The speed of Tc-99m DTPA/HMPAO radioaerosol clearance from the lungs that is represented as a slope from lungs to blood was measured in 23 male normal controls using commercial lung radioaerosol delivery units in the supine position in order to avoid the influences of gravity. The right lung was selected and three regions of interest were created for equal subdivisions of the upper, middle, and lower third. The results show that the clearance of Tc-99m DTPA/HMPAO aerosols in the upper lung is slowest. The differences between upper and lower lungs for Tc-99m DTPA/HMPAO aerosol clearances are significant. The clearance of Tc-99m DTPA aerosols was significantly faster than those of Tc-99m HMPAO in any region. The authors conclude that, although the effect of gravity disappears in the supine position in our study, the differences of aerosol clearance in different regions are still significant. Lipophilic Tc-99m HMPAO aerosols were slower than those of hydrophilic Tc-99m DTPA, which suggests there are at least two different mechanisms.

Effects of corticosteroid inhalation therapy on the deposition pattern of Tc-99m human serum albumin radioaerosols in asthma

This study evaluated the effects of steroid inhalation on the deposition pattern of Tc-99m human serum albumin (Tc-99m HSA) radioaerosols in 25 asthma patients. A total of 12 normal controls also underwent the same examination. The pattern of radioaerosol deposition was quantitatively evaluated as the percentage of total deposition (PTD) in the central, intermediate, and peripheral regions of the right lung. The baseline PTD was calculated before and after the administration of a 1-week course of inhalation therapy of 0.05 mg beclomethasone dipropionate four times daily. There were significant differences in PTD between normal controls and asthma patients. Significant differences were also found before and after corticosteroid inhalation therapy in asthma patients. In conclusion, a week-long course of beclomethasone dipropionate inhalation therapy does influence the deposition patterns of aerosols in asthma patients, based on the findings of Tc-99m HSA radioaerosol inhalation lung scintigraphy.

Alveolar integrity in pulmonary emphysema using technetium-99m-DTPA and technetium-99m-HMPAO radioaerosol inhalation lung scintigraphy

The alveolar integrity (AI) in 17 male patients with pulmonary emphysema (EMPH) diagnosed by chest x-ray was measured by 99mTc-DTPA and 99mTc-HMPAO radioaerosol inhalation lung scintigraphy.

METHODS

The patients were divided into two groups: (A) nine patients with pulmonary emphysema and normal carbon monoxide diffusion capacity (DLCO) and (B) eight patients with pulmonary emphysema and abnormal DLCO. The degree of AI damage in EMPH was presented as the slope of the time-activity curves from the dynamic left lung imagings in DTPA and HMPAO. The AI of EMPH patients were compared with the AI of 16 normal controls.

RESULTS

The results show that: (1) the slope of DTPA is larger than that of HMPAO in each of the portions of the left lung for any of the study groups; (2) statistical differences were found between the normal controls and EMPH patients in HMPAO but not in DTPA; and (3) the correlation was not good between DLCO and DTPA/HMPAO in EMPH patients.

CONCLUSION

Our results suggest that: (1) at least two different mechanisms in the lungs were at work; (2) the AI damage in EMPH developed mainly in the lipophilic part of the alveoli; and (3) the AI damage presented as slopes of DTPA/HMPAO in our study was different from the traditional pulmonary function such as DLCO.

Lung inflammation in patients with systemic lupus erythematosus detected by quantitative 67Ga-citrate lung scanning

The severity of lung inflammation in 34 patients with systemic lupus erythematosus (SLE) was measured by quantitative 67Ga-citrate lung scanning. The severity of lung inflammation in SLE was represented by the 67Ga uptake index (GUI). Quantitative 67Ga lung scanning was also performed on 20 normal controls for comparison with the SLE patients. The patients were divided into two subgroups according to the following two criteria: (a) stable or flare stage according to clinical features; or (b) positive or negative results of chest X-ray. The GUI values of the subgroups were also compared. The results revealed a trend towards higher values of GUI in SLE patients than in the normal controls. The GUI values were also higher for SLE cases with a flare stage or a negative chest X-ray than in SLE cases with a stable stage or a positive chest X-ray. The statistical results reveal that the differences in the GUI values are not significant. However, we found that (1) positive chest X-ray findings may be a later manifestation of a lung inflammation and (2) the values of GUI parallel clinical features in SLE patients.