A Co-Designed Neuromorphic Chip With Compact (17.9K F2) and Weak Neuron Number-Dependent Neuron/Synapse Modules

Many efforts have been made to improve the neuron integration efficiency on neuromorphic chips, such as using emerging memory devices and shrinking CMOS technology nodes. However, in the fully connected (FC) neuromorphic core, increasing the number of neurons will lead to a square increase in synapse & dendrite costs and a high-slope linear increase in soma costs, resulting in an explosive growth of core hardware costs. We propose a co-designed neuromorphic core (SRCcore) based on the quantized spiking neural network (SNN) technology and compact chip design methodology. The cost of the neuron/synapse module in SRCcore weakly depends on the neuron number, which effectively relieves the growth pressure of the core area caused by increasing the neuron number. In the proposed BICS chip based on SRCcore, although the neuron/synapse module implements 1∼16 times of neurons and 1∼66 times of synapses, it only costs an area of 1.79 × 10⁷ F², which is 7.9%∼38.6% of that in previous works. Based on the weight quantization strategy matched with SRCcore, quantized SNNs achieve 0.05%∼2.19% higher accuracy than previous works, thus supporting the design and application of SRCcore. Finally, a cross-modeling application is demonstrated based on the chip. We hope this work will accelerate the development of cortical-scale neuromorphic systems.

[Association between high-density lipoprotein cholesterol level and cardiovascular disease and all-cause mortality in the elderly population]

Objective: To investigate the relationship between high density lipoprotein cholesterol (HDL-C) and cardiovascular disease (CVD) and all-cause mortality in the elderly population. Methods: A total of 14 355 elderly persons aged ≥65 years, who participated in the annual physical examination in Kailuan Group in 2006 were included in this prospective cohort study. According to HDL-C level, the participants were divided into 4 groups: low-level group (HDL-C<1.30 mmol/L), intermediate-level group (1.30 mmol/L ≤HDL-C≤1.54 mmol/L), medium-high-level group (1.55 mmol/L ≤HDL-C≤1.80 mmol/L), high-level group (HDL-C≥1.81 mmol/L). Baseline data such as age, sex and blood lipid levels were collected and compared. Inpatient medical records and death information were obtained through the social security system, and CVD and all-cause mortality were analyzed. After adjusting for confounding factors, the medium-high-level group was used as the reference group. Cox proportional risk regression model was used to evaluate the impact of HDL-C on CVD and all-cause mortality events. The linear or nonlinear relationship between HDL-C level and CVD and all-cause mortality events was evaluated by restricted cubic spline regression model. Death competitive risk analysis was conducted, and sensitivity analysis was performed after excluding subjects with CVD or all-cause mortality within 1 year of follow-up and female participants. Results: The average age of this cohort was (71.5±5.5) years and follow-up time was (10.9±3.3) years. Compared with medium-high-level group, Cox proportional risk regression analysis showed that the HR (95%CI) of CVD and all-cause mortality in low-level group were 1.21 (1.06-1.38) (P<0.05) and 1.02 (0.95-1.11) (P>0.05), respectively; the HR (95%CI) of CVD events in high-level group was 1.17 (1.03-1.33) (P<0.05), and there was a marginal significant association with all-cause mortality, the HR (95%CI) was 1.07 (1.00-1.16) (0.05<P<0.1). The restricted cubic spline regression analysis showed that HDL-C was nonlinearly correlated with CVD (nonlinear correlation P<0.1), and presented a U-shaped curve trend, while HDL-C was linearly correlated with all-cause mortality (nonlinear correlation P>0.1). Conclusions: In the elderly population, the risk of CVD is lowest when the HDL-C level is 1.55-1.80 mmol/L, either high or low HDL-C is a risk factor for CVD. High HDL-C tends to be related to increased risk of all-cause mortality and low HDL-C is not related to increased risk of all-cause mortality.

[Morvan syndrome with positive anti LGI1/CASPR2 antibodies in serum/cerebrospinal fluid:a case report and literature review]

To report a typical case of Morvan syndrome with positive anti-leucine rich glioma-inactivated 1(LGI1) and contactin-associated protein 2 (CASPR2) antibodies in serum and cerebrospinal fluid. A 39-years-old female initially presented weakness of extremeties. The main symptoms included paroxysmal limb pain, wheezing, itching, muscle twitching, epilepsy, hypomnesia, dysphoria, apathy, intractable insomnia, salivation and sweating. Tests of electrolytes found hypokalemia (2.7-3.1 mmol/L) and hyponatremia (130-136 mmol/L). Arterial blood gas analysis showed hypoxemia (oxygen saturation 50%-70%). Total thyroxine (TT4) was elevated to 207 nmol/L with positive thyroid peroxidase antibody (TPO-Ab) and thyroglobulin antibody (TG-Ab). LGI1and CASPR2 antibodies (CBA method) were positive in both serum and cerebrospinal fluid, and the remaining antibodies related to autoimmune encephalitis and paraneoplastic syndrome were negative. Head MRI was almost normal, while mild abnormalities were found in electroencephalogram. Electromyography showed slightly increased voltage of left quadriceps motor unit potential. After treated with corticosteroids, IVIG and mycophenolate mofetil, the patient completely improved. Cognitive function scores recovered from MoCA/MMSE (16/24) to MoCA/MMSE (26/29). Positivity of LGI1/CASPR2 antibodies both in serum/cerebrospinal fluid are rarely seen in patients with Morvan syndrome. Steroids and immunosuppressants are suggested for treatment as early as possible.

[C-reactive protein is associated with impaired working capacity in Chinese patients with ankylosing spondylitis in paid employment: the real-world evidence from Smart-phone SpondyloArthritis Management System]

To investigate the relationship between serum C-reactive protein (CRP) levels and work impairment in patients with ankylosing spondylitis (AS) based on real-world evidence. Outpatients with confirmed AS at Chinese PLA General Hospital were recruited consecutively by Smart-phone SpondyloArthritis Management System (SpAMS) from April 2016 to April 2018. The relationship between CRP and work productivity and activity impairment questionnaire (WPAI) were evaluated. Five hundred and fifty-one outpatients with AS in paid employment were recruited. The presenteeism, overall work impairment, and activity impairment rates increased by 1.4% (1.1%, 1.8%), 1.1% (0.5%, 1.6%), and 1.7% (1.3%, 2.1%), respectively, for every 10 mg/L increase in the CRP level (all P value<0.01). However, the CRP level was not associated with absenteeism after adjusting for covariates [0.5%(-0.4%, 1.0%),P>0.05]. There is a significant association between increased serum CRP levels at baseline and the previous 7-day work impairment in patients with AS. Higher CRP levels contribute to worse presenteeism, overall work impairment, and activity impairment rates, which suggests the necessity of monitoring CRP on treatment, and also indicates that anti-inflammatory therapy may be effective for improving work productivity.

[Necessity of repeated renal arteriography in the treatment of severe hemorrhage after percutaneous nephrolithotomy]

In order to discuss the necessity of repeated renal arteriography in the treatment of severe bleeding after percutaneous nephrolithotomy, this study retrospectively analyzed the clinical data of patients with severe bleeding after percutaneous nephrolithotomy in the Department of Urology Surgery of the First Hospital of China Medical University from August 2010 to July 2020, summarily analyzing treatments, outcomes and follow-up results of 27 patients who were treated by renal arteriography more than twice. Of these 27 patients who underwent repeated renal arteriography, 23 of them were treated by two times, 4 by three times, all of whom were diagnosed as renal vascular injury. And 15 of them were diagnosed as pseudoaneurysm, 4 of them renal arteriovenous fistula, and 8 of them pseudoaneurysm combined with renal arteriovenous fistula. After clear diagnosis, all these patients were performed with renal artery embolization, after which the symptoms of hematuria and lumbar discomfort were relieved or disappeared immediately. These patients were followed up from 6 months to 5 years, without corresponding symptoms recurring and with the renal function equivalent to that before embolization. The results showed that repeated renal arteriography was of great significance in the treatment of patients with severe bleeding after percutaneous nephrolithotomy, helping to clarify the cause of bleeding and giving appropriate and timely treatment.

Pancreatic Fat is not significantly correlated with β-cell Dysfunction in Patients with new-onset Type 2 Diabetes Mellitus using quantitative Computed Tomography

Objective: Type 2 diabetes mellitus (T2DM) is a chronic condition resulting from insulin resistance and insufficient β-cell secretion, leading to improper glycaemic regulation. Previous studies have found that excessive fat deposits in organs such as the liver and muscle can cause insulin resistance through lipotoxicity that affects β-cell function. The relationships between fat deposits in pancreatic tissue, the function of β-cells, the method of visceral fat evaluation and T2DM have been sought by researchers. This study aims to elucidate the role of pancreatic fat deposits in the development of T2DM using quantitative computed tomography (QCT), especially their effects on islet β-cell function. Methods: We examined 106 subjects at the onset of T2DM who had undergone abdominal QCT. Estimated pancreatic fat and liver fat were quantified using QCT and calculated. We analysed the correlations with Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) scores and other oral glucose tolerance test-derived parameters that reflect islet function. Furthermore, correlations of estimated pancreatic fat and liver fat with the area under the curve for insulin (AUC_INS) and HOMA-IR were assessed with partial correlation analysis and demonstrated by scatter plots. Results: Associations were found between estimated liver fat and HOMA-IR, AUC_INS, the modified β-cell function index (MBCI) and Homeostatic Model Assessment β (HOMA-β). However, no significant differences existed between estimated pancreas fat and those parameters. Similarly, after adjustment for sex, age and body mass index, only estimated liver fat was correlated with HOMA-IR and AUC_INS. Conclusions: This study suggests no significant correlation between pancreatic fat deposition and β-cell dysfunction in the early stages of T2DM using QCT as a screening tool. The deposits of fat in the pancreas and the resulting lipotoxicity may play an important role in the late stage of islet cell function dysfunction as the course of T2DM progresses.

Effects of SGLT2 inhibitors on cardiovascular outcomes and mortality in type 2 diabetes: A meta-analysis

BACKGROUND

Optimal glycemic control is required to restrain the increase of cardiovascular events in patients with type 2 diabetes. The effects of sodium-glucose cotransporter-2 (SGLT-2) inhibitors on cardiovascular events and mortality in those patients are not well established. This meta-analysis was conducted to assess the effects of SGLT2 inhibitors on cardiovascular events and mortality in patients with type 2 diabetes.

METHODS

We conducted a systematic literature search of Medline, Embase and Cochrane Library and included randomized controlled trials (RCTs) of 3 different SGLT2 inhibitors (canagliflozin, dapagliflozin and empagliflozin) that evaluated the effects on cardiovascular outcomes and mortality in the final meta-analysis. The intervention arm was defined either as SGLT2 inhibitor monotherapy or as SGLT2 inhibitor add-on to other non-SGLT2 inhibitor antidiabetic agents (ADAs).

RESULTS

Forty-two trials with a total of 61,076 patients with type 2 diabetes were included in the meta-analysis. Compared with the control, SGLT2 inhibitor treatment was associated with a reduction in the incidence of major adverse cardiovascular events (MACEs) (OR = 0.86, 95% CI 0.80-0.93, P < .0001), myocardial infarction (OR = 0.86, 95% CI 0.79-0.94, P = .001), cardiovascular mortality (OR = 0.74, 95% CI 0.67-0.81, P < .0001) and all cause mortality (OR = 0.85, 95% CI 0.79-0.92, P < .0001). However, the risk of ischemic stroke was not reduced after SGLT2 inhibitor treatment in patients with type 2 diabetes (OR = 0.95, 95% CI 0.85-1.07, P = .42).

CONCLUSION

These data suggest a decreased risk of harm with SGLT2 inhibitor as a class with respect to cardiovascular events and mortality.

Anatomic extent of lymph node metastases as an independent prognosticator in node-positive major salivary gland carcinoma: A study of the US SEER database and a Chinese multicenter cohort

BACKGROUND

We aimed to explore whether the anatomic extent of lymph node metastases (AE-LNM) could independently predict prognosis of node-positive major salivary gland carcinoma (MaSGC).

METHODS

A total of 376 pathologically node-positive MaSGC patients were identified from the Surveillance, Epidemiology and End Results database and constituted the training cohort. Using the X-Tile program, these patients were divided into three groups based on AE-LNM degrees. Discrimination of overall survival (OS) and disease-specific survival (DSS) was evaluated and compared with the 8th American Joint Committee on Cancer (AJCC) pN classification. The results were externally validated by 220 patients in a Chinese multicenter cohort (Validation cohort).

RESULTS

Using the training cohort, AE-LNM was divided into Extent 1 (spread to parotid LNs or level I), Extent 2 (spread to level II-IV) and Extent 3 (spread to level V or bilateral LNs or rare LNs). Regarding both OS and DSS, the AE-LNM model revealed clear separation of survival curves, while the pN classification failed to discriminate the prognosis of pN1 and pN2 patients. When we incorporated both the AE-LNM model and AJCC pN classification into the same multivariate Cox analyses, AE-LNM was still an independent prognostic factor, while the AJCC pN classification lost its significance. These results were externally validated by the validation cohort.

CONCLUSION

AE-LNM is an independent nodal prognosticator for node-positive MaSGC and may have improved discriminative ability over the current AJCC pN classification. Integration of anatomic extent of LNM into the current AJCC N classification could be considered.

The Nedd8-activating enzyme inhibitor MLN4924 (TAK-924/Pevonedistat) induces apoptosis via c-Myc-Noxa axis in head and neck squamous cell carcinoma

Objectives

The present study aimed to reveal expression status of the neddylation enzymes in HNSCC and to elucidate the anticancer efficacy and the underlying mechanisms of inhibiting neddylation pathway.

Materials and methods

The expression levels of neddylation enzymes were estimated by Western blotting in human HNSCC specimens and bioinformatics analysis of the cancer genome atlas (TCGA) database. Cell apoptosis was evaluated by Annexin V fluorescein isothiocyanate/propidium iodide (Annexin V‐FITC/PI) stain and fluorescence‐activated cell sorting (FACS). Small interfering RNA (siRNA) and the CRISPR‐Cas9 system were used to elucidate the underlying molecular mechanism of MLN4924‐induced HNSCC apoptosis.

Results

Expression levels of NAE1 and UBC12 were prominently higher in HNSCC tissues than that in normal tissues. Inactivation of the neddylation pathway significantly inhibited malignant phenotypes of HNSCC cells. Mechanistic studies revealed that MLN4924 induced the accumulation of CRL ligase substrate c‐Myc that transcriptionally activated pro‐apoptotic protein Noxa, which triggered apoptosis in HNSCC.

Conclusions

These findings determined the over‐expression levels of neddylation enzymes in HNSCC and revealed novel mechanisms underlying neddylation inhibition induced growth suppression in HNSCC cells, which provided preclinical evidence for further clinical evaluation of neddylation inhibitors (eg, MLN4924) for the treatment of HNSCC.

Trends in clinical features and survival of oral cavity cancer: fifty years of experience with 3,362 consecutive cases from a single institution

Background

Global data demonstrate minimal improvement in the survival rate for oral cavity cancer (OCC) patients. We wished to know whether or not clinical features and survival rate have changed over time for OCC patients receiving initial treatment and follow-up at a large cancer center in China.

Methods

Clinical features and survival data were collected on patients diagnosed during the successive decades of 1960-1969 (n=253), 1970-1979 (n=497), 1980-1989 (n= 659), 1990-1999 (n=793), and 2000-2009 (n=1,160) at the Sun Yat-sen University Cancer Center.

Results

Over time, the overall 5-year survival rate for OCC patients was 52.0%. According to tumor localization, this rate was 71.4% for lip cancer, 56.3% for oral tongue cancer, and 42.7% for other parts of the oral cavity. From the 1960s to the 2000s, the 5-year survival rate steadily improved from 47.8% to 55.6% (P<0.001). Survival steadily decreased with age and was higher for women than for men in the 3 most recent decades. The survival rate for male patients was constant over time, while the rate for female patients improved dramatically. Obvious trends in clinical features over time included the following: increasing age of patients, increasing proportions of localized disease at diagnosis, decreasing proportions of diagnoses of lip cancer, decreasing proportions of diagnoses of squamous cell carcinoma, and decreasing proportions of non-surgical treatment approaches.

Conclusion

The survival rate has steadily improved for OCC patients at this cancer center.

Radiation-induced osteosarcoma of the maxilla and mandible after radiotherapy for nasopharyngeal carcinoma

Background

The increasing incidence of radiation-induced osteosarcoma of the maxilla and mandible (RIOSM) has become a significant problem that can limit long-term survival. The purpose of this study was to analyze the association of clinicopathologic characteristics with treatment outcomes and prognostic factors of patients who developed RIOSM after undergoing radiotherapy for nasopharyngeal carcinoma (NPC).

Methods

We reviewed the medical records of 53,760 NPC patients admitted to Sun Yat-sen University Cancer Center during the period August 1964 to August 2012. Of these patients, 47 who developed RISOM and met inclusion criteria were included in this study. Two of these 47 patients refused treatment and were then excluded.

Results

For all patients treated for NPC at Sun Yat-sen University Cancer Center during the study period, the total incidence of RIOSM after radiotherapy was 0.084% (47/53,760). Two patients (4.4%) had metastases at the diagnosis of RIOSM. Thirty-nine of the 45 (86.7%) patients underwent surgery for RIOSM; most patients (24/39; 61.5%) who underwent resection had gross clear margins, with 15 patients (38.5%) having either a gross or microscopic positive margin. All patients died. The 1-, 2-, and 3-year overall survival (OS) rates for the entire cohort of 45 patients were 53.3%, 35.6% and 13.5%, respectively. The independent prognostic factors associated with high OS rate were tumor size and treatment type.

Conclusions

RISOM after radiotherapy for NPC is aggressive and often eludes early detection and timely intervention. Surgery combined with postoperative chemotherapy might be an effective treatment to improve patient survival.

Serum gamma-glutamyltransferase is associated with impaired fasting glucose in Chinese adults: the Cardiometabolic Risk in Chinese (CRC) study

Recently, several studies found raised serum γ-glutamyltransferase (GGT), and traditional marker of liver damage was associated with the risk of type 2 diabetes. The purpose of this study was to investigate the relationship between GGT and impaired fasting glucose (IFG), and evaluate the modification effects of age, BMI, prehypertension, and lipids in a large sample of Chinese adults. The study samples are from a community-based health examination survey in China. The sample for our analysis included 7,309 participants. IFG was defined as FBG from 6.1 to 7.0 mmol/L. Serum GGT, lipids, blood pressure, and glucose were measured. The odds ratios (ORs, 95 % CI) of IFG across increasing quintiles of GGT were 1.00, 0.91 (0.49-1.72), 1.27 (0.68-2.38), 2.31 (1.29-4.15), and 2.42 (1.32-4.42) (P for trend < 0.0001), adjusting for age, sex, BMI, blood pressure, glucose, and lipids. We found significant interactions between age, BMI, and GGT on IFG risk. When the joint effects were examined, we found an additional effect of triglycerides (TG) and GGT levels on IFG. Our data indicate that serum GGT concentration was associated with the risk of IFG, and the association was modified by TG level.

Biodegradable poly-lactic acid based-composite reinforced unidirectionally with high-strength magnesium alloy wires

Biodegradable poly-lactic acid (PLA)--based composites reinforced unidirectionally with high-strength magnesium alloy wires (MAWs) are fabricated by a heat-compressing process and the mechanical properties and degradation behavior are studied experimentally and theoretically. The composites possess improved strengthening and toughening properties. The bending strength and impact strength of the composites with 40 vol% MAWs are 190 MPa and 150 kJ/m(2), respectively, although PLA has a low viscosity and an average molecular weight of 60,000 g/mol. The mechanical properties of the composites can be further improved by internal structure modification and interface strengthening and a numerical model incorporating the equivalent section method (ESM) is proposed for the bending strength. Micro arc oxidization (MAO) of the MAWs is an effective interfacial strengthening method. The composites exhibit high strength retention during degradation and the PLA in the composite shows a smaller degradation rate than pure PLA. The novel biodegradable composites have large potential in bone fracture fixation under load-bearing conditions.

The operation experience of endoscopic thyroidectomy by areola and axilla approach

To explore the feasibility of endoscopic thyroidectomy via breast areola and axilla approach. The clinical data of 36 cases that underwent endoscopic thyroidectomy via breast areola and axilla approach from February 2012 to December 2013 were reviewed. All cases were completed, the mean operation time was 136.3 min (95-183 min), intraoperative blood loss was 15.8 ml (5-60 ml). The average hospitalization time was 5 days (4-6 days). There were no conversions to open surgery, no permanent nerve injuries, and no cases of hypoparathyroidism. Three patients had postoperative subcutaneous ecchymosis who were cured spontaneously after 1 month. Endoscopic thyroidectomy is safe and feasible for patients with thyroid diseases with good cosmetic results, and is worthy of being widely applied for patients who have cosmetic demand.

TGF-beta induced RBL2 expression in renal cancer cells by down-regulating miR-93

PURPOSE

TGF-beta can induce G1 arrest via many mechanisms including up-regulating p21, p27, and Rb. However, as the member of Rb family, whether RBL2 is induced by TGF-beta treatment remains exclusive.

METHODS

The expression of RBL2 and miR-93 after TGF-beta treatment was determined by quantitative real-time PCR and western blot. The growth of renal cancer cells was determined by CCK-8 assays and cell cycle was determined by PI staining. The binding of miR-93 on RBL2 3'-UTR was determined by double luciferase system.

RESULTS

In renal cancer cells, TGF-beta treatment induced expression of RBL2 in a time- and concentration-dependent manner, and RBL2 mediated TGF-beta induced growth inhibition and cell cycle arrest in renal cancer cells. Furthermore, we found that miR-93 directly targeted RBL2 by binding to its 3'-UTR in renal cancer cells. Over-expression of miR-93 significantly reduced the expression of RBL2, whereas knock down of miR-93 up-regulated the expression of RBL2. More importantly, TGF-beta treatment inhibited miR-93 expression, which resulted in up-regulation of RBL2 after TGF-beta treatment.

CONCLUSION

TGF-beta induced RBL2 expression through down-regulating miR-93 in renal cancer cells. The newly identified TGF-beta/miR-93/RBL2 signal pathway reveals a new mechanism of TGF-beta induced growth arrest in renal cancer.

Relationship between serum gamma-glutamyltransferase levels and prehypertension in Chinese adults: the cardiometabolic risk in Chinese study

The authors aimed to investigate the relationship between serum gamma-glutamyltransferase (GGT) and prehypertension, as well as the modification of other metabolic risk factors in a large cohort of Chinese individuals. The data were collected via a community-based health examination survey in central China. Blood pressure, body mass index (BMI), and levels of GGT, fasting blood glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lipid indicators were measured. In total, data from 18,302 patients with available biomarkers were included in the present study. Elevated blood pressure was associated with increased GGT concentration (P<.001). After adjusting for age, sex, BMI, fasting blood glucose, lipid indicators, AST, and family history of hypertension, the association between GGT levels and prehypertension remained significant (P=.021). The adjusted odds ratios (95% confidence interval) for prehypertension across quintiles of GGT level were 1.00, 1.057 (1.012-1.334), 1.068 (0.916-1.254), 1.024 (0.851-1.368), and 1.272 (1.027-1.593), respectively. In stratified analyses, the association between GGT levels and prehypertension was significant in women but was not significant in men. Moreover, additive effect of BMI and age on the effect of GGT levels on prehypertension (both P for interaction <.001) was observed. In summary, GGT levels were positively associated with prehypertension in women, independent of other metabolic factors. Furthermore, BMI and age may amplify the effects of GGT levels on prehypertension. These findings suggest that monitoring the levels of GGT could help in the diagnosis and monitoring of prehypertension.

Low expression of PTK6/Brk predicts poor prognosis in patients with laryngeal squamous cell carcinoma

Background

Protein tyrosine kinase 6 (PTK6), also known as breast tumor kinase (Brk), was a nonreceptor tyrosine kinase containing SH3, SH2, and tyrosine kinase catalytic domains. The deregulated expression of PTK6 was observed in various human cancers. However, little was known about PTK6 expression and its clinicopathological significance in human laryngeal squamous cell carcinoma (LSCC).

Materials

PTK6 expression was evaluated in 7 pairs of surgically resectable laryngeal tissues by Western blotting and in 13 pairs of surgically resectable laryngeal tissues by reverse transcription-PCR (RT-PCR). Using immunohistochemistry, we performed a retrospective study of the PTK6 expression levels on 134 archival LSCC paraffin-embedded samples. Prognostic outcomes correlated with PTK6 were examined using Kaplan–Meier analysis and Cox proportional hazards model.

Results

The PTK6 expression level was lower in LSCC tissues than in the adjacent noncancerous epithelial laryngeal tissues by Western blots and RT-PCR. By immunohistochemical analysis, we observed high expression of PTK6 in 25 of 76 (32.9%) adjacent noncancerous epithelial laryngeal tissues and in 39 of 134 (29.1%) of LSCC, respectively. Multivariate analysis demonstrated that pN status and the expression level of PTK6 (P < 0.05) were independent and significant prognostic factors. In the primary LSCC category, median DFS (disease free survival) of high, medium and low PTK6 expression patients were 88.5 months ,74.5 months and 49.0 months (log-rank test, P = 0.002); median OS (overall survival) of high, medium and low PTK6 expression patients were 88.5 months ,76.3 months and 65.7 months (log-rank test, P = 0.002). Reduced cytoplasmic PTK6 expression in LSCC was significantly associated with late pN status (P =0.005, r = 0.27), advanced pTNM stages (III and IV) (P =0.027, r = 0.147), and poor differentiated LSCC (P <0.0001, r = 0.486). In adjacent paracancerous laryngeal epithelial samples, median DFS of high, medium and low PTK6 expression patients were 92.6 months ,75.6 months and 48.5 months (log-rank test, P = 0.020); median OS of high, medium and low PTK6 expression patients were 92.9 months ,78.9 months and 74.6 months (log-rank test, P = 0.042).

Conclusion

The present findings indicated that cytoplasmic PTK6 expression is a potential prognostic factor for survival in LSCC patients. High expression of PTK6 was associated with favorable OS and DFS in LSCC patients.

Expression and clinical significance of SIAH in laryngeal squamous cell carcinoma

SIAH is widely expressed in lot of kinds of tumors. It plays a significant role in human cancer, but its clinicopathologic and prognostic significance in laryngeal squamous cell carcinoma (LSCC) has not yet been elucidated. The SIAH expression was examined at mRNA and protein levels by real-time quantitative polymerase chain reaction (RT-PCR), Western blotting, and immunohistochemistry in LSCC tissues and adjacent normal larynx tissues. Statistical analyses were applied to test the associations between SIAH expression, clinicopathologic factors, and prognosis. Western blots and RT-PCR showed that the expression level of SIAH was lower in LSCC tissues than in adjacent normal larynx tissues. By immunohistochemical analysis, reduced expression of SIAH was found in 71.67 % LSCCs. After multivariate analysis, along with pathologic differentiation, the protein expression level of SIAH was an independent and significant predictive factor (P = 0.04). Furthermore, patients with SIAH-low tumors had a shorter disease-free survival and overall survival (P = 0.002 and P = 0.045, respectively). Our study suggests that SIAH protein expression is a valuable biomarker for LSCC. Low expression of SIAH is associated with poor disease-free survival and overall survival in LSCC patients.

Bandwidth improvement for slow light using amplification characteristics of cascaded vertical-cavity surface-emitting lasers

A scheme to improve the bandwidth of slow light using cascaded vertical-cavity surface-emitting lasers (VCSELs) is proposed and experimentally demonstrated. In the scheme, a proper adjustment on the gain peaks of two cascaded VCSELs enables the generation of the desired composite gain spectrum, which has flat-top gain and delay profiles with enhanced peak values. By employing the improved gain and delay profiles in a slow light system, a large delay can be achieved within a wider bandwidth. In the experiment, by using two cascaded VCSELs, a tunable slow light up to 135 ps for a 5 Gbits/s pseudorandom binary sequence is demonstrated with relatively low signal distortion.

Submandibular salivary gland transfer for the prevention of radiation-induced xerostomia in patients with nasopharyngeal carcinoma: 5-Year outcomes

BACKGROUND

Our aim in this study was to investigate the value of the submandibular salivary gland transfer procedure in prevention of radiation-induced xerostomia in patients with nasopharyngeal carcinoma (NPC).

METHODS

In all, there were 70 patients, consisting of a test group (36 patients) and a control group (34 patients) in a nonrandomized fashion. In the test group, the submandibular salivary gland was transferred to submental space before radiotherapy (XRT) and shielded. Salivary gland functions were evaluated by the amount of saliva and a quality of life questionnaire before and after XRT and 3 and 60 months after XRT.

RESULTS

At 5 years, the trapping and excretion functions of salivary gland were significantly better in the test group (p = .000 and p = .000). The mean weight of saliva after XRT was heavier (1.65 g vs 0.73 g, p = .000), and the incidence of xerostomia was lower in the test group, with no difference in 5-year survival and neck nodal recurrence between the 2 groups.

CONCLUSIONS

Salivary gland transfer procedure prevents XRT-induced xerostomia and improves quality of life of patients with NPC.

Reconstruction of soft-tissue defects of the head and neck: radial forearm flap or anterolateral thigh flap?

This study compared the reliability, practicability and impact to donor site functionality of radial forearm (RF) and anterolateral thigh (ALT) flaps used for the reconstruction of head and neck soft-tissue defects. The clinical data of patients who underwent reconstruction using RF flaps (n = 53) and ALT flaps (n = 21) after tumour ablation were reviewed. Pedicle length, skin area harvested and flap survival rate were compared between the two flap types. A questionnaire was used to compare the patients' perceptions of donor site functionality. Pedicle length did not significantly differ between RF and ALT flaps (7.5 vs. 9 cm, p = 0.733). A significantly larger mean area of skin was harvested in the ALT group than in the RF group (65 vs. 38 cm(2), p = 0.001). Flap survival rates did not differ between the two groups (p = 0.554). Patients in the ALT group were more satisfied with the appearance of the donor sites than were those in the RF group (p = 0.029). Significantly more patients in the RF group complained of donor site numbness than in the ALT group (p = 0.014). No ALT group patients complained of movement impairment or weakness at the donor sites, but 10% of RF group patients experienced impairment (p = 0.014) and 35% felt weakness (p = 0.001). The ALT and RF flaps showed similar practicability and reliability for the reconstruction of soft-tissue defects, but ALT flaps had fewer impacts to donor site functionality than RF flaps.

Laryngeal framework reconstruction using titanium mesh in glottic cancer after frontolateral vertical partial laryngectomy

OBJECTIVES

To investigate the feasibility and efficacy of laryngeal framework reconstruction using titanium mesh in patients with glottic cancer after frontolateral vertical partial laryngectomy.

STUDY DESIGN

Prospective study.

METHODS

Defect of laryngeal framework, caused by frontolateral vertical partial laryngectomy in nine patients with T2 or T3 squamous cell carcinoma of glottic, were reconstructed with titanium mesh from 2007 to 2009. Computed tomography (CT) and fiberscopic examinations were performed at two weeks and three months postoperatively.

RESULTS

No aspiration and laryngeal stenosis was observed in the nine patients. CT scanning showed that titanium mesh was fastened well without displacement and deformity and that there was no laryngeal stenosis. Fiberscopic inspection showed that the larynx lumen was maintained well without stricture, shrinkage, and necrosis. No titanium mesh was exposed to the larynx lumen.

CONCLUSIONS

Titanium mesh was a good alternative for reconstruction of the laryngeal framework. It provided adequate structural support to maintain airway patency.

[Application of anterolateral thigh free flap to reconstruct head and neck soft tissue defects]

BACKGROUND AND OBJECTIVE

Although anterolateral thigh (ALT) flap has the advantage of limited damage to the donor site, its clinical application is not common. This study was to study the clinical value of ALT flap in the reconstruction of head and neck soft tissue defects.

METHODS

Twenty patients receiving reconstruction of head and neck soft tissue defects using ALT flap at Sun Yat-sen University Cancer Center between November 2004 and May 2008 were retrospectively reviewed. Surgical procedures in the harvest of ALT flap were described. The surgical anatomy and successful rate were reported.

RESULTS

Twenty patients were all alive. The vessel pedicle length of ALT flap ranged from 5 cm to 14 cm, with an average of 9.9 cm. The harvested ALT flap was (4-9) cm X (6-16) cm. The skin perforator was classified into four cases of intermuscular septal branch (20%) and 16 cases of musculocutaneous branch (80%). The head and neck soft tissue defects included 14 cases (nine cases of tongue and oral floor, three cases of buccal mucosas, one case of hard palate, and one case of retromolar trigone mucosa) intraoral mucosa and six cases of facial-cervical skin defects. Except for one case, the donor sites were primarily sutured.

CONCLUSION

ALT flap is one of valuable and potential donor site for the reconstruction of head and neck soft tissue defects. It could achieve a high successful rate and causes little influence to the donor sites.

Expression and clinical significance of SPARC in clinical stage II tongue squamous cell carcinoma

BACKGROUND AND OBJECTIVE

Secreted protein acidic and rich in cysteine (SPARC) is expressed widely in malignant tumors. It is related to prognosis and biological behaviors of tumors. This study was to detect the expression of SPARC in stage II tongue squamous cell carcinoma and analyze its relationship with prognosis.

METHODS

Tongue carcinoma samples (T2N0M0) were obtained from 55 patients treated in Sun Yat-sen University Cancer Center from January 1999 to December 2003. Twenty-five squamous epithelium samples with tongue inflammation nearby were taken as control. Immunohistochemistry was used to detect the expression of SPARC. Its relationships with survival, occult lymph node metastasis and recurrence were analyzed.

RESULTS

The positive rate of SPARC was 49.1% in tongue cancer tissues and 0 in normal tissues (p < 0.001). The accumulative 5-year survival rate was significantly lower in SPARC-positive patients than in SPARC-negative patients (30.0% vs. 85.3%, p = 0.005). The positive rate of SPARC was significantly higher in tissues with occult lymph node metastasis than in those without metastasis (86.7% vs. 35.0%, p = 0.001), and higher in tissues with recurrence than in those without recurrence (100% vs. 31.5%, p < 0.001). The expression of SPARC was positively correlated to occult lymph node metastasis (r = 0.46, p < 0.001) and recurrence (r < 0.595, p < 0.001).

CONCLUSION

SPARC is highly expressed in stage II tongue squamous cell carcinoma, and positively correlated to survival, occult lymph node metastasis and recurrence.

[Correlation of cervical lymphatic metastasis to prognosis of T3-T4 glottic cancer]

BACKGROUND & OBJECTIVE

The cervical lymphatic metastasis rate of glottic cancer is low, and has seldom been reported. This study was to explore the factors related to cervical lymphatic metastasis of T3-T4 glottic cancer, and analyze its correlation to prognosis.

METHODS

Clinical data of 83 patients with T3-T4 glottic cancer, treated in Cancer Center of Sun Yat-sen University from 1992 to 2000, were reviewed retrospectively. The lymphatic metastasis rate, distribution of metastatic lymph nodes, influence factors of neck recurrence of cN0 glottic cancer, and correlation of cervical lymphatic metastasis to prognosis of T3-T4 glottic cancer were analyzed.

RESULTS

Overall lymphatic metastasis rate was 20.5%. The neck recurrence rate of cN0 patients was 14.3%. Most metastatic lymph nodes located at the ipsilateral levels II, III, and IV, while only 1 located at the contralateral level II. For cN0 patients, there was no difference in the neck recurrence rate between observation group and prophylactic cervical radiation group (P=0.772). Histopathologic differentiation affected the neck recurrence of cN0 patients (P=0.028); while T stage did not relate to the neck recurrence (P=0.217). The prognosis of cN+ patients was poorer than that of cN0 patients (P<0.001). The neck recurrence of CN0 patients did not affect the prognosis (P=0.460).

CONCLUSION

Most metastatic lymph nodes of T3-T4 glottic cancer locate at the ipsilateral levels II, III, and IV. Poor differentiation is significantly correlated to high risk of neck recurrence among cN0 patients. However, the recurrence does not affect the prognosis. Close observation should be done to the cervix of cN0 patients; while neck dissection should be done to cN+ patients.

Genetic diversity and variation of saponin contents in Panax notoginseng roots from a single farm

Radix notoginseng, the root of Panax notoginseng (Burk.) F. H. Chen, has been widely used in traditional Chinese medicine. Its main components, saponins, have been reported to have many pharmacological activities. To test the general assumption that herbs of a single species planted and harvested from a single location are uniform in chemical and genetic makeup, chemical analysis and DNA fingerprinting were carried out. High-performance TLC together with HPLC analysis were used to analyze 17 randomly sampled 3-year-old roots from a single farm for the presence of six saponins. Five roots showed distinct chemical profiles with changed ratios of ginsenosides Rd/Rg1, Re/Rg1, or Rb1/Rg1. The same samples, together with some 1- and 2-year-old samples, were also subjected to fluorescent amplified fragment length polymorphism (AFLP) analysis, and their internal transcribed spacer 2 (ITS 2) regions were sequenced. Fluorescent AFLP analysis was found to be much more polymorphic than the ITS 2 sequence and showed clear evidence of genetic diversity within the tested population. In conclusion, genetic diversity and variation of saponin contents between individual P. notoginseng roots have been detected. We suggest that genetic diversity affects the contents of the six saponins. The saponin contents variation and genetic diversity were also found among P. notoginseng root samples collected from China and Singapore markets. Since variable saponin contents may affect therapeutic efficacy, combining the use of genetic profiling with chemical profiling will help ensure greater uniformity in the quality of P. notoginseng roots. The genetic and chemical diversity within a population also provides the opportunity for breeding new cultivars with more desirable chemical constituents.

[Primary effect of submandibular salivary gland transfer in preventing radiation-induced xerostomia of nasopharyngeal carcinoma]

BACKGROUND & OBJECTIVE

Xerostomia, an ubiquitous sequelae in nasopharyngeal carcinoma (NPC) patients after radiotherapy, seriously affects life quality of the patients. This study was to investigate clinical value of submandibular salivary gland transfer in preventing radiation-induced xerostomia of NPC patients.

METHODS

A total of 70 eligible patients with NPC were recruited, and divided into test group (36 patients) and control group (34 patients). In test group, the submandibular glands were transferred to the submental spaces before conventional radiotherapy. The submental spaces were shielded during radiotherapy. Oral cavity mucous membrane reaction during radiotherapy, submandibular gland function and salivary fluid before and after radiotherapy, and questionnaire of xerostomia 3 months after radiotherapy were compared between test group and control group.

RESULTS

Acute oral cavity mucous membrane reaction was severer in control group than in test group; the incidence of stage III reaction was significantly higher in control group than in test group ( 8/34 vs. 3/36, P = 0.007). Three months after radiotherapy, trapping and excretion functions of the transferred submandibular glands were significantly better than those of the untransferred submandibular glands in test group (P = 0.001 and P = 0.000); trapping and excretion functions of the submandibular glands were significantly better in test group than in control group (P = 0.004 and P = 0.000). The mean weight of salivary fluid after radiotherapy was heavier in test group than in control group (1.41 g vs. 0.71 g). Incidence of moderate to severe degree of xerostomia was significantly higher in test group than in control group (76.5% vs. 13.9%, P = 0.000).

CONCLUSION

Submandibular gland transfer may be used to prevent radiation-induced xerostomia of NPC patients, and may improve life quality of the patients.

[Clinical analysis of xerostomia in patients with nasopharyngeal carcinoma after radiation therapy]

BACKGROUND & OBJECTIVE

There is few report on the xerostomia of the patients with nasopharyngeal carcinoma after conventional radiation therapy. Xerostomia is a serious, permanent, and ubiquitous sequelae in the patients with nasopharyngeal carcinoma after conventional radiation therapy. It has a significant impact on the patient's quality of life. This study was designed to investigate the severity of xerostomia and its impact on the quality of life in patients with nasopharyngeal carcinoma after conventional radiation therapy.

METHODS

One hundred and thirty-six patients with nasopharyngeal carcinoma, treated by conventional radiation therapy in Cancer Center, Sun Yat-sen University, were surveyed by interview at the outpatient. A questionnaire and a visual analog scale (VAS) were used in analysis of xerostomia and xerostomia-related problems.

RESULTS

Of 136 patents, 73.5% of the patients experienced a moderate to severe degree of xerostomia. 82.4% of the patients had to sip water to facilitate speech; 92.6% of the patients had to sip water to facilitate chewing and swallowing; 91.2% of the patients changed their feeding pattern (can eat only mashed food); 61.3% of the patients had to wake up to drink water because of dry mouth; 75.0% of the patients had teeth deteriorated.

CONCLUSION

73.5% of the patients with nasopharyngeal carcinoma after conventional radiation therapy experienced a moderate to severe degree of xerostomia. Xerostomia has a significant impact on the patient's speech, deglutition, sleep, and increases the morbidity rate of the tooth.

[Effectiveness evaluation and prognostic factor analysis in patients with minor salivary gland carcinoma of the hard palate]

BACKGROUND & OBJECTIVE

Minor salivary gland carcinoma of the hard palate is rare, and its long-term survival rate is high, making it difficult to evaluate the prognostic factors and the efficacy of treatment. This study was designed to evaluate the efficacy of treatment and investigate the prognostic factors of minor salivary gland carcinoma of the hard palate.

METHODS

Ninety-six cases of minor salivary gland carcinoma of the hard palate hospitalized in Cancer Center, Sun Yat-sen University, from 1964 to 2001 were reviewed retrospectively. The cumulative survival rate was analyzed by Kaplan-Meier method. The factors were compared using the log-rank test. The influencing factors were screened by Cox proportional hazards model.

RESULTS

The 5- and 10-year overall survival rates were 65.60% and 47.90%, respectively. The 5- and 10-year disease-specific survival rates for the patients treated with surgery (53 cases) and surgery + radiotherapy (35 cases) were 73.14%, 67.40% and 66.58%,46.60%,respectively. Multivariate analysis showed that age >or=50 years old,tumor size >or=3 cm,surgical margin status,and recurrence were independently associated with decreased survival rates (P< 0.05).

CONCLUSION

Surgery or surgery dominated multi-modality therapy was the principal treatment modality for minor salivary gland carcinoma of the hard palate. Age >or=50 years old, tumor size >or=3 cm, surgical margin status, and recurrence are independent factors affecting the prognosis.

The biological behaviour of human adenoid cystic carcinoma cells transduced with interleukin-2-gene

Adenoid cystic carcinoma (ACC) of the salivary glands is a highly infiltrative malignant tumour with a tendency for lung metastasis. Gene therapy could be a potentially effective therapy for ACC and its metastasis. The aims of the study were: To transduce interleukin-2 (IL-2) gene into an ACC cell line with predisposition for lung metastasis (ACC-M); to compare the bioactivity of the gene-transduced cells and the parent cell line in vitro and in vivo. The IL-2 gene was transduced via a bicistronic retroviral vector into the ACC-M cells. The growth rate and DNA cell cycles of the parent ACC-M, the control viral vector AmGCEN, and the gene transduced AmIL-2 cell cultures were compared quantitatively and by flow cytometry, respectively. The tumourigenic ability of the three cell lines was verified by inoculation in athymic nude mice. The tumours developed were extracted and compared quantitatively and histologically. There was no difference in the growth rate and the DNA count between the ACC-M, AmGCEN, and AmIL-2 cell cultures. In the animal experiment, both the ACC-M and AmGCEN cells stimulated lung metastasis in all the mice, whereas there was no tumour found in the 1 x 10(6) AmIL-2 cells inoculation. On 3 x 10(6) AmIL-2 cells stimulation, three out of six mice developed tumours but the mass and volume of the tumours were smaller than the other two groups. Under light microscopy, the ACC-M tumours were mainly poorly differentiated with minimal cellular matrix, whereas the AmIL-2 tumours were well differentiated with ample matrix. The transduction of IL-2 gene can reduce the tumourigenicity of ACC-M cells and induces tumour cell differentiation in mice. The IL-2 gene can be a potential effective gene for the treatment of adenoid cystic carcinoma of salivary glands and its lung metastasis.

[A study of the magnification of mandible pantomography image]

OBJECTIVE

To study the degree of magnification of mandible pantomography image.

METHODS

The pantomography of 50 mandible specimens marked with lead pellets were taken by TROPHY XL-90C. The distances between each markers on film and in specimen were measured.

RESULTS

The mean magnification(MM) of mandible pantomography image with TROPHY XL-90C was 1.22. MM of horizontal axle was 1.14. MM of vertical axle was 1.29. MM of horizontal axle was greatest (1.24) in the body of mandible,and lest (1.08) in genion. MM of vertical axle is similar among each regions. MM of vertical axle was greater than that of horizontal axle in all regions.

CONCLUSION

The MM parameters of mandible pantomography image were useful to estimate the size of mandible lesions and provided a basis for dental implant more exactly.

Drug-induced QT prolongation in women during the menstrual cycle

CONTEXT

Women have a higher incidence of torsades de pointes than men, but it is not known if the risk of drug-induced torsades de pointes varies during the menstrual cycle.

OBJECTIVES

To determine if the degree of QT prolongation in response to ibutilide varies with the menstrual cycle phase and to compare QT prolongation between women and men.

DESIGN AND SETTING

Cohort study of men and women who received the same intervention conducted between November 1998 and November 2000 at a general clinical research center of a university hospital.

PARTICIPANTS

A volunteer sample of 58 healthy adults (38 men and 20 women) aged 21 to 40 years.

INTERVENTION

A low dose of ibutilide (0.003 mg/kg), infused intravenously for 10 minutes. Subjects were monitored for 120 minutes. Women received the intervention on 3 separate occasions to correspond with menstrual cycle phases, which were verified by using hormonal assays.

MAIN OUTCOME MEASURE

QT interval, recorded from electrocardiogram at timed intervals during and after ibutilide infusion and standardized for variations in heart rate (QTc).

RESULTS

Maximum (mean [SD]) millisecond increase in QTc after ibutilide infusion was greater for women during menses (63 [13]) and the ovulatory phase (59 [17]) compared with women during the luteal phase (53 [14]) and compared with men (46 [16]; P =.002 vs menses and P =.007 vs ovulation). Progesterone (r = -0.40) and progesterone-to-estradiol ratio (r = -0.41), but not estradiol (r = 0.14) or testosterone (r = 0.09), were inversely correlated with ibutilide-induced QT prolongation.

CONCLUSIONS

Menstrual cycle and sex differences exist in QTc responses to ibutilide, with the greatest increase in QTc corresponding to the first half of the menstrual cycle.

[Ultramicrostructural observation on epithelial cell disdifferentiation in rat tongue carcinogenesis induced by 4NQO]

OBJECTIVE

To clarify epithelial cell ultramicrostructure changes in oral carcinogenesis.

METHODS

The epithelial cell ultramicrostructures in tongue carcinogenesis induced by 4-nitroquinoline-1-oxide (4NQO) were observed by transmission electron microscope.

RESULTS

With the progress of oral carcinogenesis, regular changes of epithelial cell were showed: decrease in tonofibril, keratohyaline granules, desmosome; and increase in mitochondria. The basement membrane was broken in some severe dysplasia (sDP) and was broken through by parts of cell processes in in situ carcinoma (ISC).

CONCLUSION

Oral carcinogenesis is a multistep process. Epithelial cell aberrant differentiation is showed by a decrease in the synthetic products of epithelium cell.

[Epidemiology of dental caries and periodontal diseases in middle school students in Suzhou City]

OBJECTIVE

To assess the prevalence of dental caries and periodontal diseases in middle school students at the ages of 11 to 13 and 15 to 17.

METHODS

Dental caries and periodontal diseases were assessed strictly by "national survey table of dental caries and periodontal diseases for school students".

RESULTS

The study group consisted of 20 581 students. The percentage of dental caries, DMFT and DMFS in students 11 to 13 years of age were 23.6%,0.40 and 0.54, respectively. The corresponding results were 29.76%, 0.64 and 0.87 for students 15 to 17 years of age, respectively. The percentage of gingivitis and dental calculus in students 11 to 13 years were 75.33% and 35.86%, respectively. The corresponding values in students 15 to 17 years of age were 73.1% and 44.91%, respectively. Female students have significantly few gingivitis and dental calculus than male students in both groups.

CONCLUSION

Compared with the students at the same ages in other cities, students in Suzhou city have low percentage of dental caries and periodontal diseases.

[Experimental study of abnormal cell proliferation and differentiation in rat tongue carcinogenesis induced by 4NQO]

OBJECTIVE

To clarify the phenotypic characteristics of abnormal cell proliferation and differentiation in oral carcinogenesis.

METHODS

The expressions of gp230, a marker of epithelium cell differentiation, and proliferating cell nuclear antigen (PCNA) in rat tongue carcinogenesis induced by 4-nitroquinoline-1-oxide (4NQO) were detected by LSAB immunohistochemical staining.

RESULTS

With the progress of oral carcinogenesis abnormal proliferation and differentiation patterns were indicated by reduced expression of gp230 and increased expression of PCNA.

CONCLUSION

Oral carcinogenesis is the result of mucosa epithelium cell aberrant proliferation and differentiation.

Effects of all-trans retinoic acid and interferon-gamma on expression of RAR beta gene in Tca8113 cells

OBJECTIVE

All-trans-retinoic acid (ATRA) and interferons (IFNs) have been proven to synergistically amplify growth inhibition and apoptosis in the tongue squamous carcinoma cell line (Tca8113). Nuclear retinoic acid receptor-beta (RAR beta) was the key gene that mediated retinoid activity for squamous carcinoma cells. In order to understand the mechanism of ATRA combined with IFN gamma inhibiting growth of Tca8113 cells, this investigation focused on RAR beta mRNA expression.

MATERIALS AND METHODS

In this experiment, RT-PCR method was used to analyze the RAR beta expression level, and viable cell count assay was carried out for growth inhibition studies.

RESULTS

All-trans-retinoic acid (1 microM) and IFN gamma (1000 u/mL) inhibited cell growth by 39.2% and 44.4%, respectively. Synergistic inhibition of cell proliferation by 86.7% was found under combined treatment. The combination of suboptimal concentrations of ATRA (0.1 microM) with IFN gamma (1000 u/mL) showed a much stronger additive inhibitory effect on cell proliferation. ATRA (1 microM) and IFN gamma (1000 u/mL) increased RAR beta expression to 4 times and 3 times, respectively. The expression of RAR beta increased 12 times after treatment with combined ATRA and IFN gamma treatment.

CONCLUSIONS

These observations indicated that the use of combined ATRA and IFN may lead to enhanced antitumor effects. These results also suggested that ATRA and IFN mediated upregulating expression of RAR beta may play an important role in synergistic inhibition of proliferation in Tca8113 cells.

Female gender is a risk factor for torsades de pointes in an in vitro animal model

Recent clinical observations indicate that female gender is associated with a higher risk of developing torsades de pointes (TdP) cardiac arrhythmia. In this study, we used the Langendorff technique in isolated perfused rabbit hearts and the whole-cell patch-clamp technique in ventricular myocytes to examine the gender difference in TdP incidence and gain insight into the underlying mechanisms. Isolated rabbit hearts were perfused by using the Langendorff technique. TdP was induced by abrupt changes of cycle length (deltaCL) in the presence of Tyrode's solution containing 1 mM 4-aminopyridine (4AP) and 50% reduced Mg2+ and K+ (low K/Mg). The effects of 1 mM 4AP on cardiac potassium currents were characterized by using the patch-clamp technique. Results demonstrated that (a) no significant gender difference was observed in the absolute QT interval before or after 4AP perfusion in the presence of low K/Mg; (b) 4AP caused marked QT prolongation in the ECG; (c) a significantly higher TdP incidence (nine of 12) was found in female hearts compared with male hearts (three of 12; p < 0.05); (d) 1 mM 4AP primarily inhibited Ito, although a slight inhibition of IKr also occurred in low-K/Mg Tyrode's solution. (e) No inhibition of IK1 was observed. (f) No gender difference was found in the potassium current block produced by 4AP. Female gender is associated with a higher incidence of TdP in an experimental isolated heart model and mechanisms subsequent to QT prolongation may contribute to such a gender difference.

Comparison of tegaserod (HTF 919) and its main human metabolite with cisapride and erythromycin on cardiac repolarization in the isolated rabbit heart

Tegaserod (HTF 919) is a new drug being developed for gastrointestinal motility disorders. Because other gastrointestinal prokinetic agents, such as cisapride and erythromycin, cause slowing of cardiac repolarization and have been implicated in the development of the potentially fatal ventricular arrhythmia, torsades de pointes, a study was initiated to determine whether tegaserod and its main human metabolite adversely influence cardiac repolarization. By using isolated Langendorff-perfused rabbit hearts, we show that QT intervals remain unchanged at concentrations of tegaserod from 0.5 to 10 microM. It was not until the tegaserod concentration was increased to 50 microM (roughly 500-5,000 times more concentrated than those typically found in human plasma after administration of recommended clinical dosages), that a small, but significant increase in the QT interval (12+/-4%; p < 0.05; n = 4) was observed. No significant changes in QT occurred in the presence of the tegaserod metabolite at any of the concentrations tested (0.5-50 microM). In contrast, cisapride caused QT lengthening at concentrations as low as 0.1 microM, with significant QT increases occurring when 5-50 microM cisapride was used (22+/-4% to >70%, respectively; p < 0.01; n = 4). Erythromycin also caused significant lengthening of QT intervals (11+/-2%; p < 0.001; n = 4), although 100 microM concentrations of this drug were required to achieve this effect. These results demonstrate that both cisapride and erythromycin can slow cardiac repolarization at therapeutic doses and that tegaserod's lack of QT prolongation at therapeutic doses suggests that it has the potential to be a safer alternative to cisapride as a gastrointestinal prokinetic agent.

Prolongation of QT interval in isolated feline hearts by antipsychotic drugs

Some antipsychotic drugs have been found to prolong the QT interval on electrocardiographic (ECG) recordings, a phenomenon which, when severe, may facilitate the occurrence of complex ventricular arrhythmias such as torsade de pointes. However, the effects of these drugs on the cardiac repolarization process have not been evaluated extensively. This study was designed to examine the potency of five antipsychotic drugs in lengthening the QT interval of the perfused feline heart: haloperidol, risperidone, sertindole, clozapine, and olanzapine. The hearts were infused with increasing concentrations of drugs (0.1-20 micromol/L) for 40-minute intervals at each concentration. ECG recordings were made, with signals amplified and data recorded on a strip chart recorder. Four representative beats from each set of three signal recordings were chosen for QT interval measurement. Our data indicated that all tested drugs prolonged the QT interval in a concentration-dependent manner (p < 0.01). Haloperidol and risperidone were significantly more potent than sertindole, clozapine, and olanzapine (p < 0.001). At a concentration of 0.5 micromol/L over a 40-minute infusion interval, haloperidol lengthened the interval by 26.2+/-0.7%, risperidone by 19.4+/-2.2%, and sertindole by 8.9+/-3.5% (p < 0.05 compared with baseline); clozapine and olanzapine were less potent. Although species differences may limit extrapolation of our findings to humans, the cardiac potassium channels of felines clearly resemble those of humans. This model may serve as the basis for further studies of drug-induced prolongation of the QT interval and precipitation of ventricular arrhythmias.