Cardiac arrhythmias induced by chloral hydrate in rhesus monkeys

Chloral hydrate has been long used as a safe sedative and hypnotic drug in humans. However, reports on its cardiovascular adverse effects have been published from time to time. The present study was undertaken to use Rhesus monkeys as a model to define the dose regiment of chloral hydrate at which cardiac arrhythmias can be induced and the consequences of the cardiac events. Male Rhesus monkeys of 2-3 years old were intravenously infused with chloral hydrate starting at 50 mg/kg with an increasing increment of 25 mg/kg until the occurrence of cardiac arrhythmias. In addition, a traditional up-and-down dosing procedure was applied to define a single dose level at which cardiac arrhythmias can be induced. The data obtained showed that when the sequentially escaladed dose reached 125 mg/kg, cardiac arrhythmias occurred in all monkeys tested. The single effective dose to cause cardiac arrhythmias calculated from the crossover analysis was 143 ± 4 mg/kg. This value would be equivalent to 68.6 ± 1.9 mg/kg for children and 46.4 ± 1.3 mg/kg for adults in humans. Under either multiple or single dose condition, cardiac arrhythmias did not occur before 40 min after the onset of anesthesia induced by chloral hydrate. Cardiac arrhythmias were recovered without help at the end of the anesthesia in most cases, but also continued after the regain of consciousness in some cases. The cardiac arrhythmias were accompanied with compromised cardiac function including suppressed fractional shortening and ejection fraction. This study thus suggests that cautions need to be taken when chloral hydrate is used above certain levels and beyond a certain period of anesthesia, and cardiac arrhythmias induced by chloral hydrate need to be closely monitored because compromised cardiac function may occur simultaneously. In addition, patients with cardiac arrhythmias induced by chloral hydrate should be monitored even after they are recovered from the anesthesia.

Lipoic acid: an immunomodulator that attenuates glycinin-induced anaphylactic reactions in a rat model

The purpose of this study was to evaluate the attenuation effects of consuming a small dose of lipoic acid on soybean glycinin-induced hypersensitivity using a rat model. Sensitized by gavage with glycinin, weaned rats were orally supplemented with the diet containing 12.5 mug of lipoic acid/g (per diet). Results showed that untreated, sensitized rats demonstrated an increase in the level of serum IgE, the level of histamine release, and incidence of diarrhea and reduced growth performance compared with the controls (P < 0.05). Lipoic acid significantly (P < 0.05) improved growth performance while reducing mast cell numbers, the level of serum IgE, and the level of histamine release. Lipoic acid supplementation altered the balance of cytokines, attenuated the Th2-type immune response, and amended the ratio of CD4(+) to CD8(+) T cells (P < 0.05). Our results suggest that a small dose of lipoic acid has the potential to be an immunomodulator to prevent soybean-induced allergies.

Overall survival using local excision techniques with and without radiation compared with APR for stage I rectal cancer: A SEER based analysis

4032

Background: The standard of care for Stage I rectal cancer is radical resection. Increasingly, local therapies have been used to decrease morbidity and preserve sphincter control. Due to increased risk of local recurrence with less radical surgery, patients often receive adjuvant radiation. This analysis compares the outcomes of sphincter sparing treatment with radical surgery in Stage I rectal cancer. Methods: Using the Surveillance, Epidemiology and End-Results (SEER) registry, we performed a query of patients with Stage T1–2N0 (T=4 cm or less) rectal adenocarcinoma between 1988 and 2003 who were treated with either local excision alone (LE), local excision followed by radiotherapy (LE+RT) or abdominoperineal resection (APR). APR was selected as comparison group to select for a similar cohort of patients with distal tumors that would be eligible for LE. Kaplan-Meier analysis was performed to compare overall survival for patients receiving radical surgery versus local therapy. Subgroup survival analysis was performed by T-stage (T1 vs T2). Results: 2,144 patients were identified: 744 were treated with LE alone, 197 underwent LE+RT, and 1203 underwent APR. Patients undergoing LE ± RT had a median survival (MS) of 131 vs 121 months in the APR group (p=0.574). When comparing LE vs LE+RT, there was no difference in MS for the whole cohort (134 vs 108 months, p=0.39). However, on subgroup analysis there was a significant survival benefit in favor of LE+RT for T2N0 only (104 vs 74 months, p=0.048). For T1N0, the MS for LE+RT was 161 vs 147 months for LE (p=0.621). Comparing with APR, patients undergoing LE+RT had a MS of 108 vs 121 months in the APR group (p=0.684). For T1N0, the MS for LE+RT was 161 vs 153 months for APR (p=0.62). For T2N0 patients, the MS for LE+RT was 104 vs 114 months for APR (p=0.726). Conclusions: According to this analysis, there was no statistical difference in survival for patients with Stage I rectal carcinoma undergoing APR versus LE+RT. Selected patients with T1N0 may undergo local excision alone. However, patients with T2N0 disease should undergo adjuvant radiation after local excision. The risks and benefits of these treatment strategies should be weighed and treatment should be individualized.

No significant financial relationships to disclose.

Radical prostatectomy in clinically localized prostate cancer—The risk of extraprostatic spread by NCCN risk group and its implications for adjuvant therapy: An analysis of 23,988 patients

5125

Background: Swanson et al recently reported an update of SWOG 8794 (ASTRO 2008, oral presentation) revealing a 10% absolute overall survival benefit at 15 years with adjuvant radiation therapy for patients with extraprostatic extension (EPE) or positive margins after radical prostatectomy (RP). In this population based analysis, we analyze and report on the pathologic rates of EPE or positive margins in clinically localized prostate cancer as well as how often these patients have received adjuvant radiation therapy. Methods: The Surveillance, Epidemiology and End Results (SEER) registry was used to identify patients between 2004–2005 with clinically staged T1-T2c prostate cancer who underwent RP. Patients were stratified using NCCN risk groups into low (T1c- T2a, PSA less than 10ng/ml, Gleason 2–6), intermediate (T2b, PSA 10–20ng/ml, Gleason 7), and high (T2c, PSA greater than 20ng/ml, Gleason 8–10). Results: 23,988 patients were identified: 6,314 in the NCCN low risk group (LR), 12,052 in the NCCN intermediate risk group (IR), and 5,622 in the NCCN high risk group (HR). Overall, 68.2% of patients had organ-confined disease with negative margins. However, the risk of EPE or positive margins increased with the NCCN risk group, PSA value, and Gleason score (see table ). Of those who met criteria for adjuvant radiation, 11.9% received the treatment: 4.7% of the LR group, 9.2% of the IR group and 18.9% of the HR group. Conclusions: This is, to our knowledge, the largest reported multi-institutional surgical series of clinically localized prostate cancer. Patients can use this data to be counseled on their risk of requiring adjuvant radiation based on their pre-treatment parameters. This data also reveals that nearly one third of all patients met the indications for adjuvant radiation, but only a small percentage of them received this treatment.

[Table: see text]

No significant financial relationships to disclose.

Utilization of radiation therapy in early-stage Hodgkin disease and its impact on survival

8511

Background: Despite numerous randomized trials confirming the benefit of consolidation radiation therapy (RT) in the management of early stage Hodgkin disease (HD), utilization of RT in this setting remains variable. We performed a population-based analysis to assess the utilization of RT and its impact on overall and cause specific survival. Methods: The surveillance, epidemiology and end results (SEER) registry was used to identify patients aged 15–75 years diagnosed between 1990–2004 with early stage (stage I-IIA/B) HD, excluding nodular lymphocyte predominant HD. Kaplan-Meier analysis was performed to evaluate the effect of RT on overall survival (OS) and cause-specific survival (CSS). Subgroup survival analyses were also performed by era of treatment (1990–1997 and 1998–2004), sex, and patient age (<30, 30–50, and >50 years). Results: A total of 9729 patients met inclusion criteria. Median age of all patients was 34 years. The majority (71.3%) had nodular sclerosis (NS) type HD. By clinical stage, 3399 (34.9%) were stage I, and 6330 (65.1%) were stage II. 5352 patients (55%) received RT. RT was more likely to be employed during the early era of treatment, in younger patients, females, non-Blacks, and in NS, mixed cellularity and lymphocyte-rich HD. For the entire cohort, RT was associated with a significant (p<0.001) improvement in OS and CSS (hazard ratio of 0.537 and 0.437, respectively). The benefit of RT for OS and CSS remained significant for all subgroups analyzed including the era of treatment, sex, and age (p≤0.001). Conclusions: In this large population-based series of early stage HD patients, the use of RT is associated with a significant OS and CSS benefit across all subgroups. Current efforts in clinical trials have aimed at decreasing the utilization of RT among this patient population. This shift in practice is reflected in the data presented here. The omission of RT from the treatment paradigm, however, appears to be related with diminished survival.

No significant financial relationships to disclose.

Cement oscillation increases interlock strength at the cement-bone interface, with commentary

Modern cementing techniques aim to improve the interlock between bone and cement and to establish a durable interface. Cement penetration is generally believed to influence interface failure, but current methods for improving the cement-bone interface are inadequate. Oscillation is the reciprocated movement of an object through its balanced position, or the quantum physics of systematic fluctuation back and forth near an average value (or trimmed value). To increase the interlock strength at the cement-bone interface, we designed a cement oscillator according to the principles of vibrational mechanics. To evaluate the effect of oscillation on the quality of interlock strength at the cement-bone interface, we randomly divided 156 femoral bones of adult pigs into 2 groups, oscillated and control, and performed mechanical tests to assess interlock strength at the cement-bone interface. The filling effect of bone cement was observed and analyzed under a stereomicroscope, and then each oscillated femur was compared with a control femur. The interlock strength at the cement-bone interface in the oscillated group was significantly greater than in the control group (P<.05), and the filling effect in the oscillated group was also better than that in the control group (P<.05). Our findings show that oscillation of bone cement significantly increases interlock strength at the cement-bone interface, point the way for clinicians to develop a high-performance and pragmatic fixation technique for prostheses to increase interlock strength, and will be of considerable practical importance in helping to prevent aseptic loosening of cemented prostheses.

Predicting disordered regions in proteins using the profiles of amino acid indices

BACKGROUND

Intrinsically unstructured or disordered proteins are common and functionally important. Prediction of disordered regions in proteins can provide useful information for understanding protein function and for high-throughput determination of protein structures.

RESULTS

In this paper, algorithms are presented to predict long and short disordered regions in proteins, namely the long disordered region prediction algorithm DRaai-L and the short disordered region prediction algorithm DRaai-S. These algorithms are developed based on the Random Forest machine learning model and the profiles of amino acid indices representing various physiochemical and biochemical properties of the 20 amino acids.

CONCLUSION

Experiments on DisProt3.6 and CASP7 demonstrate that some sets of the amino acid indices have strong association with the ordered and disordered status of residues. Our algorithms based on the profiles of these amino acid indices as input features to predict disordered regions in proteins outperform that based on amino acid composition and reduced amino acid composition, and also outperform many existing algorithms. Our studies suggest that the profiles of amino acid indices combined with the Random Forest learning model is an important complementary method for pinpointing disordered regions in proteins.

Large-scale prediction of long disordered regions in proteins using random forests

Background

Many proteins contain disordered regions that lack fixed three-dimensional (3D) structure under physiological conditions but have important biological functions. Prediction of disordered regions in protein sequences is important for understanding protein function and in high-throughput determination of protein structures. Machine learning techniques, including neural networks and support vector machines have been widely used in such predictions. Predictors designed for long disordered regions are usually less successful in predicting short disordered regions. Combining prediction of short and long disordered regions will dramatically increase the complexity of the prediction algorithm and make the predictor unsuitable for large-scale applications. Efficient batch prediction of long disordered regions alone is of greater interest in large-scale proteome studies.

Results

A new algorithm, IUPforest-L, for predicting long disordered regions using the random forest learning model is proposed in this paper. IUPforest-L is based on the Moreau-Broto auto-correlation function of amino acid indices (AAIs) and other physicochemical features of the primary sequences. In 10-fold cross validation tests, IUPforest-L can achieve an area of 89.5% under the receiver operating characteristic (ROC) curve. Compared with existing disorder predictors, IUPforest-L has high prediction accuracy and is efficient for predicting long disordered regions in large-scale proteomes.

Conclusion

The random forest model based on the auto-correlation functions of the AAIs within a protein fragment and other physicochemical features could effectively detect long disordered regions in proteins. A new predictor, IUPforest-L, was developed to batch predict long disordered regions in proteins, and the server can be accessed from

Platelet-associated immunoproteins (PAIg): specificity of measurement

Platelet-associated Ig (PAIg) is raised in patients with idiopathic thrombocytopenic purpura. However, it is also raised in conditions not traditionally considered to be immune mediated. The latter finding suggests that raised PAIg may be an epiphenomenon of thrombocytopenia. The assays currently available do not distinguish between PAIg present due to a specific Fab binding or present due to non-specific binding of Ig via Fc or complement receptors. In this paper we show that by prior incubation with normal rabbit serum, an assay for PAIg can be made specific for Fab binding.