Clinical Significance of Arginine Signaling in Patients with Cervical Cancer Receiving Cisplatin Chemoradiation Therapy

PURPOSE/OBJECTIVE(S)

Many human malignancies do not produce sustainable amounts of arginine (Arg) because the rate-limiting enzyme, arginosuccinate synthetase 1 (ASS1), in the biosynthesis of Arg has been silenced. We investigated the clinical significance of ASS1 expression on cisplatin chemoradiation therapy for cervical cancer.

MATERIALS/METHODS

A total of 118 consecutive patients with FIGO stages IB to IVA cervical cancer who had received platinum-based concurrent chemoradiotherapy were identified and their clinical courses were reviewed. Immunohistochemical studies were performed on their formalin-fixed, paraffin-embedded tissues. The prognostic value of ASS1 was investigated by performing univariate and multivariate analyses on factors affecting patient survival.

RESULTS

Median follow-up for all patients was 5.5 years (range: 1 to 23.5 years). Overexpression of ASS1 was an independent prognostic factor. The 5-year disease-free survival for patients with ASS1-positive tumors was 72.3%, compared with 51.6% for patients with ASS1-negative tumors (P = 0.02). Univariate Cox proportional hazards models showed positive ASS1 immunostaining (hazard ratio [HR]: 0.50, 95% CI: 0.28-0.90), FIGO stage (HR: 0.33, 95% CI: 0.18-0.59) and brachytherapy (HR: 0.22, 95% CI: 0.10-0.48) were significant prognostic factors affecting disease-free survival. In multivariate analyses, positive ASS1 remained an independent significant prognostic factor for DFS (HR = 0.45, 95% CI: 0.25-0.83).

CONCLUSION

Overexpression of ASS1 is an independent prognostic factor for cervical cancer patients receiving cisplatin concurrent chemoradiotherapy.

Comparison of eight modern preoperative scoring systems for survival prediction in patients with extremity metastasis

BACKGROUND

Survival is an important factor to consider when clinicians make treatment decisions for patients with skeletal metastasis. Several preoperative scoring systems (PSSs) have been developed to aid in survival prediction. Although we previously validated the Skeletal Oncology Research Group Machine-learning Algorithm (SORG-MLA) in Taiwanese patients of Han Chinese descent, the performance of other existing PSSs remains largely unknown outside their respective development cohorts. We aim to determine which PSS performs best in this unique population and provide a direct comparison between these models.

METHODS

We retrospectively included 356 patients undergoing surgical treatment for extremity metastasis at a tertiary center in Taiwan to validate and compare eight PSSs. Discrimination (c-index), decision curve (DCA), calibration (ratio of observed:expected survivors), and overall performance (Brier score) analyses were conducted to evaluate these models' performance in our cohort.

RESULTS

The discriminatory ability of all PSSs declined in our Taiwanese cohort compared with their Western validations. SORG-MLA is the only PSS that still demonstrated excellent discrimination (c-indexes>0.8) in our patients. SORG-MLA also brought the most net benefit across a wide range of risk probabilities on DCA with its 3-month and 12-month survival predictions.

CONCLUSIONS

Clinicians should consider potential ethnogeographic variations of a PSS's performance when applying it onto their specific patient populations. Further international validation studies are needed to ensure that existing PSSs are generalizable and can be integrated into the shared treatment decision-making process. As cancer treatment keeps advancing, researchers developing a new prediction model or refining an existing one could potentially improve their algorithm's performance by using data gathered from more recent patients that are reflective of the current state of cancer care.

International Validation of the SORG Machine-learning Algorithm for Predicting the Survival of Patients with Extremity Metastases Undergoing Surgical Treatment

BACKGROUND

The Skeletal Oncology Research Group machine-learning algorithms (SORG-MLAs) estimate 90-day and 1-year survival in patients with long-bone metastases undergoing surgical treatment and have demonstrated good discriminatory ability on internal validation. However, the performance of a prediction model could potentially vary by race or region, and the SORG-MLA must be externally validated in an Asian cohort. Furthermore, the authors of the original developmental study did not consider the Eastern Cooperative Oncology Group (ECOG) performance status, a survival prognosticator repeatedly validated in other studies, in their algorithms because of missing data.

QUESTIONS/PURPOSES

(1) Is the SORG-MLA generalizable to Taiwanese patients for predicting 90-day and 1-year mortality? (2) Is the ECOG score an independent factor associated with 90-day and 1-year mortality while controlling for SORG-MLA predictions?

METHODS

All 356 patients who underwent surgery for long-bone metastases between 2014 and 2019 at one tertiary care center in Taiwan were included. Ninety-eight percent (349 of 356) of patients were of Han Chinese descent. The median (range) patient age was 61 years (25 to 95), 52% (184 of 356) were women, and the median BMI was 23 kg/m2 (13 to 39 kg/m2). The most common primary tumors were lung cancer (33% [116 of 356]) and breast cancer (16% [58 of 356]). Fifty-five percent (195 of 356) of patients presented with a complete pathologic fracture. Intramedullary nailing was the most commonly performed type of surgery (59% [210 of 356]), followed by plate screw fixation (23% [81 of 356]) and endoprosthetic reconstruction (18% [65 of 356]). Six patients were lost to follow-up within 90 days; 30 were lost to follow-up within 1 year. Eighty-five percent (301 of 356) of patients were followed until death or for at least 2 years. Survival was 82% (287 of 350) at 90 days and 49% (159 of 326) at 1 year. The model's performance metrics included discrimination (concordance index [c-index]), calibration (intercept and slope), and Brier score. In general, a c-index of 0.5 indicates random guess and a c-index of 0.8 denotes excellent discrimination. Calibration refers to the agreement between the predicted outcomes and the actual outcomes, with a perfect calibration having an intercept of 0 and a slope of 1. The Brier score of a prediction model must be compared with and ideally should be smaller than the score of the null model. A decision curve analysis was then performed for the 90-day and 1-year prediction models to evaluate their net benefit across a range of different threshold probabilities. A multivariate logistic regression analysis was used to evaluate whether the ECOG score was an independent prognosticator while controlling for the SORG-MLA's predictions. We did not perform retraining/recalibration because we were not trying to update the SORG-MLA algorithm in this study.

RESULTS

The SORG-MLA had good discriminatory ability at both timepoints, with a c-index of 0.80 (95% confidence interval 0.74 to 0.86) for 90-day survival prediction and a c-index of 0.84 (95% CI 0.80 to 0.89) for 1-year survival prediction. However, the calibration analysis showed that the SORG-MLAs tended to underestimate Taiwanese patients' survival (90-day survival prediction: calibration intercept 0.78 [95% CI 0.46 to 1.10], calibration slope 0.74 [95% CI 0.53 to 0.96]; 1-year survival prediction: calibration intercept 0.75 [95% CI 0.49 to 1.00], calibration slope 1.22 [95% CI 0.95 to 1.49]). The Brier score of the 90-day and 1-year SORG-MLA prediction models was lower than their respective null model (0.12 versus 0.16 for 90-day prediction; 0.16 versus 0.25 for 1-year prediction), indicating good overall performance of SORG-MLAs at these two timepoints. Decision curve analysis showed SORG-MLAs provided net benefits when threshold probabilities ranged from 0.40 to 0.95 for 90-day survival prediction and from 0.15 to 1.0 for 1-year prediction. The ECOG score was an independent factor associated with 90-day mortality (odds ratio 1.94 [95% CI 1.01 to 3.73]) but not 1-year mortality (OR 1.07 [95% CI 0.53 to 2.17]) after controlling for SORG-MLA predictions for 90-day and 1-year survival, respectively.

CONCLUSION

SORG-MLAs retained good discriminatory ability in Taiwanese patients with long-bone metastases, although their actual survival time was slightly underestimated. More international validation and incremental value studies that address factors such as the ECOG score are warranted to refine the algorithms, which can be freely accessed online at https://sorg-apps.shinyapps.io/extremitymetssurvival/.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Integral-based parallel algorithm for the fast generation of the Zernike polynomials

The integral representation of the Zernike radial functions is well approximated by applying the Riemann sums with a surprisingly rapid convergence. The errors of the Riemann sums are found to averagely be not exceed 3 ×10^-14, 3.3×10^-14, and 1.8×10^-13 for the radial order up to 30, 50, and 100, respectively. Moreover, a parallel algorithm based on the Riemann sums is proposed to directly generate a set of radial functions. With the aid of the graphics processing units (GPUs), the algorithm shows an acceleration ratio up to 200-fold over the traditional CPU computation. The fast generation for a set of Zernike radial polynomials is expected to be valuable in further applications, such as the aberration analysis and the pattern recognition.

P5294Metabolically healthy obese is associated with better left atrial function and lower risk of adverse cardiovascular events including atrial fibrillation

Purpose

Metabolic syndrome (MetS) and obesity are both crucial risk factors for heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF). However, the prognostic value of utilizing left atrial (LA) deformation imaging in metabolically healthy obese (MHO) or metabolically unhealthy normal weight (MUNW) subjects remains largely unexplored.

Methods

Speckle-tracking echocardiography was used to evaluate LA strain and strain rate among 3,915 subjects free from clinical heart failure (mean age: 50.0±10.6 years, 66.2% male) undergoing annual cardiovascular health survey. Metabolically unhealthy was defined by the presence of at least one MetS component or history of cardiovascular disease. Participants were categorized as: metabolically healthy normal weight (MHNW), metabolically unhealthy normal weight (MUNW), metabolically healthy overweight/obese (MHO), metabolically unhealthy overweight/obese (MUO).

Results

Markedly decreased LA strain, early-diastolic LA strain rate and increased LA stiffness were observed with metabolic disorders (all trend p: <0.05). During a median follow-up period of 3.68 years, significantly higher risk of primary endpoints (death, heart failure, major cardiovascular events) was observed in MUO vs. MHO (HR=1.87, p=0.005) and MUNW vs. MHNW (HR=2.82, p=0.004). Similar patterns with incident AF (MUO vs MHO: HR=3.05, p=0.001, MUNW vs MHNW: HR=4.04, p=0.002) were also observed. After multivariate adjustment, risk of AF remained associated with low LA strain (β=−0.07, p<0.001), systolic LA strain rate (β:−0.05, p=0.007) and high LA stiffness (β=0.18, p<0.001).

Comparison between metabolic groups MHNW (N=1107) MUNW (N=255) p (MUNW vs MHNW) MHO (N=1859) MUO (N=694) p (MUO vs MHO) Age 48±10.57 54.29±11.52 <0.001 49±10.02 54.21±10.49 <0.001 LA GLS (%) 40.6±7.68 37.16±7.5 <0.001 36.77±7.66* 33.58±8.01‡ <0.001 LA SRs 1.79±0.41 1.76±0.48 NS 1.63±0.39* 1.55±0.41‡ <0.001 LA SRe 2.11±0.62 1.8±0.63 <0.001 1.68±0.55* 1.48±0.52‡ <0.001 LA stiffness 0.17±0.08 0.22±0.12 <0.001 0.21±0.11* 0.25±0.13‡ <0.001 *p<0.001 for MHO vs MHNW, ‡p<0.001 for MUO vs MUNW. LA GLS = left atrial global longitudinal strain, LA SRs = left atrial systolic strain rate, LA SRe = left atrial early-diastolic strain rate, NS = non-significant.

Kaplan-Meier curves of adverse events

Conclusion

Metabolic abnormality may contribute to certain aspects of mechanistic LA dysfunction tightly linked to clinical events, even with normal lean body mass. Our observations may be insightful for targeted interventions in higher-risk patients with subclinical atrial dysfunction.

Wave representation for asymmetric elliptic vortex beams generated from the astigmatic mode converter

An analytical wave representation is derived to express the asymmetric elliptic vortex beams generated by using an astigmatic mode converter to transform the asymmetric Hermite-Gaussian modes. The effect of the spatial asymmetry on the elliptic vortex beam can be straightforwardly considered in the analytical wave representation. A detailed comparison with experimental intensity patterns and phase structures is made. The good agreement between experimental results and theoretical analyses confirms the characterization and generation of the asymmetric elliptic vortex beams.

Exploring elliptical vortex beams with the spatial damping effect

A general integral formula is analytically derived to represent the wave function of elliptical vortex modes. The derived formula can be straightforwardly employed to take account of spatial damping to explore vortex structure. Spatial damping is found to cause the central degenerate singularity of the circular vortex mode to be split into several singularities with different topological charges. For the non-circular vortex beam, the influence of spatial damping on the distribution of singularities is not significant. Theoretical analyses are confirmed to agree very well with the experimental measurements.

Generating high-power asymmetrical Laguerre-Gaussian modes and exploring topological charges distribution

We employ an off-axis pumped Nd:YVO₄ laser and control the reflectance of output coupler to directly generate asymmetrical Hermite-Gaussian (HG) modes with various transverse orders. By using an astigmatic mode converter, the generated asymmetrical HG modes are straightforwardly transformed into asymmetrical Laguerre-Gaussian (LG) modes with a crescent-like shape. The average output power of all the crescent-shaped LG modes can exceed 1W at the pump power of 4W. Furthermore, experimental results are theoretically verified by resonant modes derived from the inhomogeneous Helmholtz equation with the localized source distribution. Theoretical resonant modes are also used to explore the dependence of the phase structures of LG modes on the system loss. As the loss increases, it is found that the singularities at the origin will be rearranged and new singularities are formed in the outside region with average orbital angular momentum remaining unchanged.

[Mechanism of lung injury of rats induced by inhalation of white smoke from burning smoke pot]

Objective: To explore mechanism of lung injury of rats induced by inhalation of white smoke from burning smoke pot. Methods: Forty-eight Sprague Dawley rats were divided into control group (n=12) and injury group (n=36) according to the random number table. Rats in injury group were placed in smoke-induced injury experimental equipment fulled with white smoke from burning smoke pot for 5 minutes to make lung injury, and rats in control group were placed in smoke-induced injury experimental equipment fulled with air for 5 minutes to make sham injury. Six rats in injury group at post injury hour (PIH) 6, 24, and 72 and six rats in control group at PIH 72 were collected to observe pathological changes of lung tissue and pathological score of rats in the two groups by hematoxylin-eosin staining, to detect expression of nuclear factor-κB (NF-κB) p65 mRNA in lung tissue of rats by reverse transcriptional polymerase chain reaction, and to detect content of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 in lung tissue of rats by enzyme-linked immunosorbent assay. Data were processed with one-way analysis of variance and t test. Results: At PIH 72, lung tissue structure of rats in control group was clear and complete, with no inflammatory cell infiltration. At PIH 6, there was edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group. At PIH 24, edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group aggravated. At PIH 72, area of edema in lung tissue of rats in injury group was enlarged, with obvious hemorrhage and inflammatory cell infiltration. At PIH 6, 24, and 72, pathological score of lung tissue of rats in injury group was (3.43±0.86), (5.39±0.93), and (9.99±0.84) points, respectively, obviously higher than that of rats in control group at PIH 72 [(2.11±0.20) points, t=3.659, 8.450, 22.355, P<0.05]. As time post injury prolonged, pathological scores of lung tissue of rats in injury group were significantly increased (F=121.244, P<0.01). At PIH 6, 24, and 72, expression of NF-κB p65 mRNA in lung tissue of rats in injury group was 15.5±4.3, 25.9±1.8, 30.9±3.5 respectively, significantly higher than that of rats in control group at PIH 72 (7.8±0.8, t=4.315, 20.445, 14.408, P<0.01). As time post injury prolonged, expression of NF-κB p65 mRNA in lung tissue of rats in injury group gradually increased (F=32.691, P<0.01). At PIH 6, 24, and 72, content of TNF-α, IL-1β, and IL-6 in lung tissue of rats in injury group was significantly higher than that of rats in control group at PIH 72, respectively (t=7.650, 8.968, 6.827, 6.726, 8.978, 3.460, 5.420, 13.289, 16.438, P<0.01). At PIH 24, content of TNF-α and IL-1β in lung tissue of rats in injury group was higher than that of rats in the same group at PIH 6 and 72, respectively (t=3.409, -2.549, 4.047, -4.100, P<0.05). At PIH 24 and 72, content of IL-6 in lung tissue of rats in injury group was respectively higher than that of rats in the same group at PIH 6 (t=8.273, 9.711, P<0.05). Conclusions: After inhaling white smoke from burning smoke pot, rats are inflicted with lung injury by increasing expression of NF-κB p65 mRNA and content of TNF-α, IL-1β, and IL-6, and induce pathological changes of edema, hemorrhage, and inflammatory cell infiltration of lung tissue.

[Lentivirus media miR-1246 knockdown inhibits tumor growth and promotes apoptosis of SiHa cells]

Objective: To study the effect of lentivirus-mediated microRNA (miR) -1246 RNA interference (RNAi) on biological characteristics and behaviors in cervical cancer cells as well as to identify the downstream signaling pathways affected. Methods: MiR-1246 specific cDNA was synthesized and cloned into the recombinant lentiviral vector (LV-miR-1246-inhibitor) . The SiHa cells were devided into three groups: no viral infection (negative control, NC) , infection with control virus (LV-NC) , and infection with miR-1246-inhibitor virus (LV-miR-1246-inhibitor) . The expression of the miR-1246 was detected by reverse transcription (RT) -PCR. Cell growth was analyzed by cell counting kit 8 (CCK-8) assay. The invasion was dectected by transwell matrige gel. Cell apoptosis was detected by flow cytometer. The growth of xenograft tumors was also investigated. Expression of thrombospondin-2 (THBS2) , matrix metalloproteinase (MMP) 2, 9 were also evaluated in the cells. Results: (1) The expression level of miR-1246 in SiHa cells (0.11±0.13) was significantly lower in group LV-miR-1246-inhibitor than those in the group LV-NC and the group NC (1.14±0.86 and 1.30±0.73, respectively; P<0.01) . (2) The proliferation of SiHa was also markedly suppressed in CCK-8 at 96 hours (P<0.01) . (3) The number of group LV-miR-1246-inhibitor was significantly less than those in the LV-NC and NC groups in transwell invasion assay (71±4, 162±5 and 188±5, respectively; P<0.01) . (4) The apoptosis rate of SiHa cells in the group LV-miR-1246-inhibitor [ (16.10±3.37) %] was significantly lower than those of group LV-NC and group NC [ (5.67±0.89) % and (1.78±0.08) %,P<0.01]. (5) The tumor volume in the nude mice group LV-miR-1246-inhibitor [ (287±59) mm(3)] was significantly lower than those in the LV-NC and NC groups [ (571±137) and (657±144) mm(3), respectively; P<0.01]. (6) Compared with the LV-NC group and the NC group, THBS2 protein expression in the tumor tissue of the nude mice in the group LV-miR-1246-inhibitor was significantly increased (P<0.05) , while the expression levels of MMP-2 and MMP-9 protein were significantly decreased (P<0.01) . Conclusion: These results suggest that miR-1246 functions during cervical cancer pathogenesis and tumor formation via the THBS2, MMP signaling pathway.

Characterization and generation of high-power multi-axis vortex beams by using off-axis pumped degenerate cavities with external astigmatic mode converter

The generalized geometric mode with several high-order Hermite-Gaussian (HG) beams localized on ray periodic orbits in the degenerate resonator is generated by an off-axis pumped Nd:YVO₄ laser, by performing beam transformation via an astigmatic mode converter, the generalized geometric modes are found that can be converted into the multi-axis vortex beams with the bundled-rings structures. Experimental results reveal that the generated multi-axis vortex beams can preserve quite stable beam structures even under high-power operation. Moreover, the radius of the bundled rings for the multi-axis vortex beams can be flexibly adjusted by the off-axis pumping to lead to vortex structures with easily controlled orbital angular momentum distribution. The good agreement between the experimental and theoretical results of propagation evolution for the astigmatic transformation of generalized geometric modes further verify the feasibility of using the proposed system to realize various high-powered, multi-center vortex beams with good reliability and predictability.

Role of TNF-α in renal damage in mice showing hepatic steatosis induced by high fat diet

The present study was designed to investigate the role of TNF-α in renal damage observed in mice with hepatic steatosis. We induced hepatic steatosis in mice using high fat diet and treated mice with ectanercept at the dose sufficient to block TNF-α receptors or vehicle for 1 month. Plasma TNF-α, total cholesterol (TC), triglyceride (TG), LDL-cholesterol (LDL-C), and HDL-cholesterol (HDL-C) were determined at the end of this treatment. Renal damage was identified by histologic observation and the higher of serum blood urea nitrogen (BUN) and creatinine. Also, changes of PPAR-δ in kidney and renal mesangial cell (RMC) were analyzed using Western blot. Plasma TNF-α was markedly raised in mice showing hepatic steatosis. However, the levels of blood lipids (TC, TG, HDL-C, and LDL-C) and TNF-α were not modified by the treatment of etanercept although the hepatic steatosis has been improved. Etanercept shows renal protection from histological identification and recovery of serum BUN and creatinine levels. Moreover, restoration of PPAR-δ expression by etanercept was observed in mice kidney. Direct effect of TNF-α on PPAR-δ expression was also characterized in RMC cell. We suggest that renal damage in mice with hepatic steatosis is mainly induced by increase of TNF-α through the decrease of renal PPAR-δ. Etanercept could block TNF-α receptors to restore PPAR-δ and improve renal function in mice with hepatic steatosis.

Advertising of antihypertensive medicines and prescription sales in Australia

BACKGROUND

Drug promotion is one of the main factors that influence prescribing practices, but there are limited data available to quantify the relationship between drug advertising and prescription sales.

AIM

To investigate the relationship between advertising for antihypertensive medicines and prescription sales in Australia between 1993 and 2002.

METHODS

Retrospective observational study. Advertising trends were monitored by counting the number of advertisements published in three Australian medical journals. Monthly prescription dispensing data were obtained from Drug Utilisation Sub-Committee and expressed as numbers of defined daily doses/1000 inhabitants/day. Linear regression and cross-correlations of time series were used in the analysis.

RESULTS

The drug classes the most heavily advertised, angiotensin-converting enzyme inhibitors and calcium channel blockers, were also the most prescribed during the study period, while the drugs the least advertised, thiazide diuretics and beta-blockers, were the least used. In 5 of the 7 main antihypertensive classes, the product the most advertised was also the most prescribed. Other factors, such as the publication of large clinical trials, may have also influenced prescribing patterns.

CONCLUSION

Prescription sales of antihypertensives in Australia are correlated with promotional advertising. The newest and most expensive medicines may be chosen over older effective drugs by prescribers. New policies on drug promotion control need to be developed.

Using direct nanoimprinting to study extraordinary transmission in textured metal films

In this paper, we describe a thermal embossing imprint method, which we name "nano-imprinting in metal" (NIM), for patterning metal films with a variety of profiles. Metal films exhibiting either perforated hole-arrays or corrugated structures with various surface morphologies can be fabricated rapidly. The SPR phenomenon allowed energy coupling to the other side of the textured metal film, causing a dramatic increase in the transmission. As a technique for readily controlling the working wavelength and transmittance, the NIM method has great potential for application in various optoelectronic devices.

Modulation effects on Landau levels in a monolayer graphene

Magnetoelectronic properties of a single-layer graphene are studied by the Peierls tight-binding model. A new numerical technique is developed to obtain a band-like Hamiltonian matrix. A spatially modulated magnetic field B' could drastically alter the Landau levels due to a uniform magnetic field B. The modulation effects include enhancement in dimensionality, change of energy dispersions, destruction of state degeneracy and creation of band-edge states. The dispersionless Landau levels, those at the Fermi levels excepted, become the 1D parabolic bands. The density of states thus exhibits many pairs of asymmetric prominent peaks. The height, frequency and number of pronounced peaks strongly depend on the modulation strength. These characteristics are hardly affected by the period and direction when B' is much weaker than B. The predicted results could be verified by experimental measurements on magneto-optical absorption spectra.

Predicting postoperative nausea and vomiting with the application of an artificial neural network

BACKGROUND

Several medications have proved to be useful in preventing postoperative nausea and vomiting (PONV). However, routine antiemetic prophylaxis is not cost-effective. We evaluated the accuracy and discriminating power of an artificial neural network (ANN) to predict PONV.

METHODS

We analysed data from 1086 in-patients who underwent various surgical procedures under general anaesthesia without antiemetic prophylaxis. Predictors used for ANN training were selected by computing the value of chi(2) statistic and information gain with respect to PONV. The configuration of the ANN was chosen by using a software tool. Then the training of the ANN was performed based on data from a training set (n=656). Testing validation was performed with the remaining patients (n=430) whose outcome regarding PONV was unknown to the ANN. Area under the receiver operating characteristic (ROC) curves were used to quantify predictive performance. ANN performance was compared with those of the Naïve Bayesian classifier model, logistic regression model, simplified Apfel score and Koivuranta score.

RESULTS

ANN accuracy was 83.3%, sensitivity 77.9% and specificity 85.0% in predicting PONV. The areas under the ROC curve follow: ANN, 0.814 (0.774-0.850); Naïve Bayesian classifier, 0.570 (0.522-0.617); logistic regression, 0.669 (0.623-0.714); Koivuranta score, 0.626 (0.578-0.672); simplified Apfel score, 0.624 (0.576-0.670). ANN discriminatory power was superior to those of the other predicting models (P<0.05).

CONCLUSIONS

The ANN provided the best predictive performance among all tested models.

Endothelin-1 regulates parathyroid hormone expression of human parathyroid cells

OBJECTIVE

Parathyroid cells synthesize and release endothelin-1 (ET-1). ET-1 displays an in vitro inhibitory effect on basal parathyroid hormone (PTH) secretion and also counteracts PTH hypersecretion stimulated by low calcium. Such effects are further demonstrated in vivo, independent of the changes in calcitonin. We propose that ET-1 may regulate the pathogenesis of uremic hyperparathyroidism. However, this was not directly demonstrated in human parathyroid glands.

DESIGN

Hyperplastic parathyroid glands are obtained from the surgical operation for uremic hyperparathyroidism. Cells are isolated by enzyme digestion and treated with ET-1, and are assessed for PTH mRNA expression. PTH in the plasma and the medium is measured by a newly developed method to detect the whole PTH (1-84).

PATIENTS

Uremic patients with severe secondary hyperparathyroidism and ultrasonography-proved hypertrophy of parathyroid glands received elective surgical approaches under general anesthesia. The resected glands were immediately taken to the laboratory for fresh isolation.

MEASUREMENTS

Following ET-1 treatment, PTH mRNA expression is evaluated by RT-PCR method. ET-1 is detected with radioimmunoassay kit and PTH is measured by a new commercially available Duo PTH kit.

RESULTS

ET-1 exhibited a dose-dependent inhibitory effect (from 10(-12) - 10(-7) M) on PTH mRNA expression of parathyroid cells, either in the basal or in the low-calcium-stimulated states. Release of PTH into the medium is also gradually inhibited by the increase in ET-1 concentrations.

CONCLUSIONS

Our results demonstrate that ET-1 attenuates PTH mRNA expression in freshly isolated human parathyroid cells, and PTH release is also decreased. This result is consistent with our previously reported in vitro and in vivo experiments.

Decreased B cells and IgA-secreting B cells partially explain the high prevalence of IgA deficiency in dialysis patients

AIMS

We previously reported 2 hemodialysis (HD) patients with recurrent infections and selective immunoglobulin A deficiency (IgAD). We further demonstrated that serum IgA levels were lower and the prevalence of IgAD was higher in uremic patients. The exact mechanisms of IgAD in uremic patients largely remained unclear. In some patients, it was caused by anti-IgA antibody neutralization and subsequent destruction. We performed the present study to survey if there is any defect in IgA production.

MATERIALS AND METHODS

288 patients were initially included for examination of serum immunoglobulins. 16 normal persons, 16 dialysis patients without IgAD, and 12 dialysis patients with IgAD were enrolled after the initial examination. Blood was drawn into heparinized tubes. WBC counts and lymphocyte percentage were examined by a CBC counter. Lymphocytes were separated by the Ficoll-Paque method. Flow cytometry was utilized to isolate the B cell and IgA-secreting B cell after staining with CD 19 phycoerythrin and FITC-conjugated rabbit anti-human IgA antibody.

RESULTS

There is no significant difference between WBC counts or total lymphocyte counts of these 3 groups. However, we found a lower percentage of total lymphocyte counts in dialysis patients, either with or without IgAD. The total B cell numbers were lower in dialysis patients with IgAD. In addition, there were fewer IgA-secreting B cells in dialysis patients with IgAD.

CONCLUSION

Decreased B cell and IgA-secreting B cell counts are seen in uremic patients with IgAD. This, in turn, indicates that there might be a defect of IgA production in some patients, rather than IgA destruction by anti-IgA antibodies as seen in some other patients. Further study is needed to investigate the mechanisms of decreased B cells and IgA-secreting B cells.

San-Huang-Xie-Xin-Tang attenuates inflammatory responses in lipopolysaccharide-exposed rat lungs

In this study, the potential anti-inflammatory effect of San-Huang-Xie-Xin-Tang (SHXT) and its main component baicalin on LPS-induced lung injury were investigated and compared to the profile of dexamethasone (DEXA) in a pre-clinical animal model. Post-treatment with SHXT (75 mg/kg), baicalin (1.5 mg/kg) and DEXA (0.5 mg/kg), significantly inhibited LPS-induced hypotension, lung edema and acute survival rates. Western blotting analysis results indicated that all of them significantly inhibited LPS-induced iNOS, TGF-beta, p38MAPK, and ICAM-1 expressions in the lung tissues. Results from ELISA analysis showed that SHXT, baicalin and DEXA all decreased plasma levels of IL-1beta, TNF-alpha, and MCP-1 caused by LPS. Based on these findings, SHXT and baicalin decreased plasma concentrations of IL-1beta, TNF-alpha, MCP-1, and expressions of TGF-beta, ICAM-1, phosphorylated p38 MAPK, and iNOS, which were associated with lung injury and lethality. These evidences indicated that SHXT and baicalin showed strong anti-inflammatory activity, similar to that observed for DEXA, and therefore implicated that herbal SHXT might be therapeutically useful for the treatment of endotoxic lung injury.

Adsorption and Thermal Reactions of Alkanethiols on Pt(111): Dependence on the Length of the Alkyl Chain

The adsorption and thermal decomposition of alkanethiols (R-SH, where R = CH3, C2H5, and C4H9) on Pt(111) were studied with temperature-programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS) with synchrotron radiation. Dissociation of sulfhydryl hydrogen (RS-H) of alkanethiol results in the formation of alkanethiolate; the extent of dissociation at an adsorption temperature of 110 K depends on the length of the alkyl chain. At small exposure, all chemisorbed CH3SH, C2H5SH, and C4H9SH decompose to desorb hydrogen below 370 K and yield carbon and sulfur on the surface. Desorption of products containing carbon is observed only at large exposure. In thermal decomposition, alkanethiolate is proposed to undergo a stepwise dehydrogenation: R'-CH2S --> R'-CHS --> R'-CS, R' = H, CH3, and C3H7. Further decomposition of the R'-CS intermediate results in desorption of H2 at 400-500 K and leaves carbon and sulfur on the surface. On the basis of TPD and XPS data, we conclude that the density of adsorption of alkanethiol decreases with increasing length of the alkyl chain. C4H9SH is proposed to adsorb mainly with a configuration in which its alkyl group interacts with the surface; this interaction diminishes the density of adsorption of alkanethiols but facilitates dehydrogenation of the alkyl group.

7-84 parathyroid hormone fragments are proportionally increased with the severity of uremic hyperparathyroidism

AIMS

Recent progress in PTH assay has revealed that the intact PTH assay kit in current use does not differentiate between the truncated 7-84 PTH molecule and the 1-84 PTH molecule. In our series, we examined the effectiveness of a new PTH assay as a noninvasive method of evaluating severity of uremic hyperparathyroidism.

METHODS AND MATERIALS

Two hundred and seventy hemodialysis (HD) patients recruited from three HD centers were included and divided into subgroups according to the conventional iPTH assay results. Pre-dialysis blood samples were collected and subjected to two different PTH assays: "intact" PTH assay (iPTH) and "whole" PTH (wPTH) assay. Two biochemical markers of bone remodeling were also examined.

RESULTS

In all cases, PTH levels determined by the wPTH assay were in the average 32.3% lower than those determined by the iPTH assay. The difference of the results of the two PTH assay methods, which indicated the portion of 7-84 PTH fragments of the total PTH molecules measured with the iPTH assay, was gradually increased while the severity of uremic hyperparathyroidism increased. Biochemical markers of bone formation/resorption showed a similar change.

CONCLUSION

The portion of the 7-84 PTH fragments and markers of increased bone turnover increased in proportion to the severity of uremic hyperparathyroidism. This finding disproves the hypothetical role of 7-84 PTH fragments alone as the noninvasive marker of low-turnover bone disease in HD patients.

Edema due to protein-losing enteropathy--a disorder rarely considered by nephrologists

In the differential diagnosis, protein-losing enteropathy (PLE) is a rarely considered explanation of edema. Three such cases are reported in this article. Clinical presentations varied from severe generalized anasarca and respiratory distress to mild pitting edema on the pretibial surface. Hypoalbuminemia (< 35 g/l) was another common finding in addition to edema. The patients were carefully examined to exclude other causes of hypoalbuminemia. Two patients experienced diarrhea. Endoscopic studies (plus biopsies) for any mucosal lesion in the stomach and colon were also performed. PLE was confirmed by the positive radionuclide scanning results after infusing intravenous 99mTc human serum albumin (USA). Investigation for the etiologies showed intestinal lymphangiectasia in 1 patient, Menetrier's disease in another, and no recognizable cause in the third. The severe anasarca of the patient with intestinal lymphangiectasia didn't respond to corticosteroids and albumin supplement plus large doses of furosemide. She died of overwhelming pulmonary infection despite the use of powerful antibiotics (ceftriaxone and amikacin). We planned to treat the Menetrier's disease patient with somatostatin to decrease the exocrine activities of the intestinal tract. The patient with presumable idiopathic PLE had the least severe edema and was not treated with any medication. In addition to the above patients, another 3 patients with hypoalbuminemia and edema were also noted to have positive HSA scan results. However, 2 of these patients had systemic lupus erythromatosus and the third pulmonary tuberculosis and biopsy-proven membranous nephropathy. Treatment of their underlying diseases showed satisfactory remission of edema.