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Background: Gross total resection of neuroblastoma is associated with lymphatic leaks that can delay postoperative resumption of treatment. To prevent postoperative lymphatic leak, we introduced systematic lymphatic repair (SLR), which involved oversewing the entire edge of the disrupted lymphatic plane after neuroblastoma resection. We sought to study the impact of SLR on postoperative lymphatic leak and time to return to treatment., Methods: We reviewed 60 neuroblastoma patients who underwent gross total resection at KK Women's and Children's Hospital. Patient, disease, and operative factors were correlated with surgical drainage, treatment delay and length of stay (LOS). Among patients with sufficient records, the interaction between variables associated with drainage, delay and LOS outcomes were compared in 14 patients who had SLR versus 35 historical controls who had targeted lymphatic repair (TLR)., Results: Postoperative drain duration and volume were significantly higher in tumors with ≥2 image-derived risk factors (IDRFs, P = 0.005 and P = 0.013, respectively) or vessel encasement (P = 0.031 and P = 0.024, respectively). Longer LOS was significantly associated with ≥2 IDRFs (P = 0.006). All forms of suture repair of lymphatics and use of Tachosil™ were associated with significantly longer postoperative drain duration (P < 0.05); the former was also associated with significantly higher total drain volume (P < 0.05) - indicating appropriate use of these adjuncts in patients at risk of chyle leak. In patients who had suture repair of lymphatics, SLR was significantly associated with reduced postoperative interval to chemotherapy resumption (P = 0.014, two-way ANOVA)., Conclusion: A systematic approach to repair of lymphatic channels following neuroblastoma resection can significantly reduce time to postoperative resumption of treatment., Type of Study: Clinical Research., Level of Evidence: III., Competing Interests: Conflicts of interest None., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: The natural history of DCIS may not be progression to invasive breast cancer (IBC). Accelerated partial breast irradiation (APBI) has emerged as an alternative to whole breast radiotherapy (WBRT). The purpose of this study was to assess the impact of APBI on DCIS patients., Materials and Methods: Eligible studies from 2012 to 2022 were identified in PubMed, Cochrane Library, ClinicalTrials, and ICTRP. A meta-analysis was done comparing recurrence rates, breast-related mortality rates, and adverse events of APBI versus WBRT. A subgroup analysis of 2017 ASTRO Guidelines "Suitable" and "Unsuitable" groups was performed. Forest plots and quantitative analysis were done., Results: Six studies were eligible (3 on APBI versus WBRT, 3 on APBI suitability). All had a low risk of bias and publication bias. The cumulative incidence was the following for APBI and WBRT respectively: IBTR was 5.7% and 6.3% with odds ratio of 1.09, 95% CI [0.84, 1.42], mortality rate was 4.9% and 5.05%, and adverse events was 48.87% and 69.63%. All had no statistical significance between groups. Adverse events were found to favor the APBI arm. Recurrence rate was significantly less in the Suitable group with an odds ratio 2.69, 95% CI [1.56, 4.67], favoring it over the Unsuitable group., Conclusion: APBI was comparable to WBRT in terms of recurrence rate, breast cancer-related mortality rate, and adverse events. APBI was not inferior to WBRT and showed better safety in terms of skin toxicity. Patients classified as suitable for APBI had significantly lesser recurrence rate., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Aims: This review aims to examine the prevalence estimate of low resilience among health care professionals and identify the factors affecting the prevalence., Background: Health care professionals experience high levels of stress. Understanding the health care professionals' resilience may provide an insight into how they perform in a highly stressed environment., Evaluation: A comprehensive search of 11 databases was conducted. Studies that provided prevalence rates for low resilience among health care professionals working in a health care setting were included. Meta-analyses, sensitivity, subgroup analyses and meta-regression were conducted., Key Issues: Among 27,720 studies, 41 studies (N = 17,073) across 16 countries were included. The prevalence of low resilience was 26% (95% CI: 20-32). Subgroup analyses indicated that types of resilience measures affect resilience prevalence significantly. A higher prevalence of low resilience was observed among allied health professions during the COVID-19 pandemic in the Middle East., Conclusions: This review indicated the prevalence of low resilience and type of resilience measurement instruments that affected the prevalence., Implications for Nursing Management: This review provides a roadmap to design tailored, discipline-specific and sustainable resilience training for nurses. Nursing managers should monitor the working hours and workload of nursing staffing in order to provide a protective working environment. This is a systematic review, and the PROSPERO registration number is CRD42021235350., (© 2022 John Wiley & Sons Ltd.)

Objective: The purpose of this study was to examine the acute effects of pacing at different ventricular sites on hemodynamics and left ventricular (LV) rotational mechanics using speckle-tracking echocardiography (STE) in a porcine model., Design: A prospective laboratory investigation., Setting: University research laboratory., Participants: Yorkshire pigs., Interventions: In 9 pigs, after midline sternotomy, epicardial pacing was performed from the right ventricular outflow tract (RVOT), right ventricular apex (RVA), and LV free wall., Measurements and Main Results: Two-dimensional STE and conductance catheter-derived LV pressure-volume measurements were made to determine the impact of pacing from various sites on LV rotational parameters (twist/untwist) and hemodynamics. RVOT pacing caused the least decrease in end-systolic pressure from baseline (-9.5%), when compared with RVA (-19.1%) and LV (-23.4%). Systolic and diastolic parameters (Emax, Tau) also were different among RVOT (4.7±0.8 mmHg/mL, 32±4 ms), RVA (3.9±0.7 mmHg/mL, 37±6 ms), and LV sites (3.6±0.8 mmHg/mL, 42±7 ms). Similar to the effects of pacing on hemodynamics, RVOT pacing better preserved LV twist (11.1±1.8 v 8.6±1.7, 5.9±0.7 °) and untwisting rate (64.6±8.5 v 56.2±5.3, 48.2±8.5 °/s) when compared with RV apical pacing and LV pacing. Furthermore, prolongation of conduction from LV lateral to anteroseptal at LV base (26.5±3.8 v 13.8±3.3 ms, p<0.05) and LV midpapillary muscle level (35.6±5.6 v 14.1±2.4 ms, p<0.05) was observed with LV pacing compared with RVOT pacing., Conclusions: The present data showed that the LV twist/untwist and cardiac systolic and diastolic function were least affected by RVOT pacing. This finding may be explained by the proximity of this location to the native ventricular conduction system., (Copyright © 2015 Elsevier Inc. All rights reserved.)

The number of patients with heart failure presenting for surgery continues to rise, and anesthesiologists are increasingly being called upon to provide quality, safe care in the operating room for patients with low ejection fraction (EF). Perioperative goals in the management of these patients include maintaining forward flow, promoting inotropy without inducing or exacerbating ischemia, and returning patients to their preoperative level of function after surgery. Oftentimes, these goals can be met with pharmacologic support, including the use of calcium channel blockers, phosphodiesterase inhibitors, and novel agents, such as nesiritide and levosimendan. Many patients with diminished EF have implantable cardioverter-defibrillators (ICDs) in place. These devices can be complex to manage, and concern often arises regarding electromagnetic interference from monopolar cautery. Although simply placing a magnet on the device will often disable the antitachycardia interventions of an ICD, this is not always the case. The safest way to manage an ICD in the perioperative period is to interrogate and reprogram the device before and after surgery. Another helpful device in dealing with patients with low EF, particularly those in acute cardiogenic shock, is the intra-aortic balloon pump. These devices can serve a critical role in managing patients who have inadequate responses to pharmacologic therapy or in whom vasopressor and inotropic support are suboptimal because of concerns for increasing myocardial work. With full understanding of available pharmacologic agents, and an appreciation of the capabilities of ICDs and intra-aortic balloon pumps, anesthesiologists will be better equipped to meet the perioperative needs of the patient with low EF.

Superior mesenteric artery (SMA) syndrome is a rare but potentially fatal complication following spinal fusion for scoliosis. The aims of our study were to identify clinical features and evaluate their importance in SMA syndrome following posterior spinal fusion (PSF) in adolescent idiopathic scoliosis (AIS) patients and to recommend a simple approach for the recognition and management of SMA syndrome. This is an IRB-approved study. Three patients in our series and 11 patients from other published case reports who underwent PSF for adolescent idiopathic scoliosis were included in our study. Patient demographics, clinical presentation, investigations, and management were recorded and analyzed. In this combined series of 14 patients (mean age 14.8 years), the main presenting clinical features included vomiting of any kind (92.9%), abdominal pain/tenderness (57.1%), abdominal distension (42.9%), bilious vomiting (35.7%), and hypoactive bowel sounds (28.6%). Most patients presented within 2 weeks of surgery (71.4%). In total, 50% of patients presented with both vomiting (of any kind) and abdominal tenderness. The number of presenting symptoms appeared to be directly related to the severity of SMA syndrome. Our second patient had intermittent vomiting on postoperative day (POD) 3, which was initially considered as insignificant; she was discharged on POD 9 and readmitted for recurrent vomiting, during which SMA syndrome was diagnosed. Our first patient presented in the classical manner. Our third patient had bilious vomiting after discharge that started on POD 13 and increased in frequency until readmission on POD 27. Vomiting and abdominal pain are nonspecific symptoms following PSF; differentiating between SMA syndrome and postoperative ileus can be challenging. The highest index of suspicion applies to patients who present within the first week with symptoms of vomiting and abdominal pain. We propose an algorithm for the management of SMA syndrome, which includes a focused clinical assessment to evaluate for intestinal obstruction, followed by an abdominal radiography and barium contrast study if clinical assessment is positive. An early referral to general surgery should be considered especially for high-risk patients (BMI<5% percentile, sagittal kyphosis). Early diagnosis of SMA syndrome allows for early intervention, reducing the likelihood of future complications and need for surgery.

A direct and facile method for micro-landscaping of Ag nanoparticles on reduced graphene oxide (rGO) is presented. This method employs a focused laser beam to achieve local reduction of Ag(+) ions to Ag NPs by laser irradiation on a GO film that is submerged in AgNO3 solution. Using this method, the Ag nanoparticles can be directly anchored on a rGO film, creating a microlandscape of Ag nanoparticles on the rGO film. In addition, varying the intensity of the laser beam can control the shapes, sizes and distributions of Ag nanoparticles. The resulting hybrid materials exhibit surface enhanced Raman scattering of up to 16 times depending on the size and number density of silver nanoparticles. In addition, the hybrid Ag-rGO material shows superior photoresponse when compared to rGO.

Objective: The aim of this study was to determine the pertinent anesthetic considerations for patients undergoing surgical sympathectomy for electrical storm (incessant ventricular tachycardia (VT) refractory to traditional therapies)., Design: This is a retrospective review of a prospective database., Setting: This single-center study took place in a university hospital setting., Participants: Twenty-six patients were enrolled., Interventions: Fifteen patients underwent left-sided sympathectomy, whereas 11 patients underwent bilateral sympathectomy., Measurements and Main Results: Anesthetic management of these patients was quite complex, requiring invasive monitoring, transesophageal echocardiography, one-lung ventilation, programming of cardiac rhythm management devices, and titration of vasoactive medications. Paired t test of hemodynamic data before, during, and after surgery showed no significant difference between preoperative and postoperative blood pressure values, regardless of whether the patient underwent unilateral or bilateral sympathectomy. Eight patients remained free of VT, three patients responded well to titration of oral medications, and one patient required 2 radiofrequency ablations after sympathectomy to control his VT. Three patients continued to have VT episodes, although reduced in frequency compared with before the procedure. Four patients were lost to followup. Overall, five patients within the cohort died within 30 days of the procedure. No patients developed any anesthetic complications or Horner's syndrome. The overall perioperative mortality (within the first 7 days of the procedure) was 2 of 26, or 7.7%., Conclusions: The anesthetic management of patients undergoing surgical sympathectomy for electrical storm can be quite complex, because these patients often present in a moribund and emergent state and cannot be optimized using current ACC/AHA guidelines. Expertise in invasive monitoring, transesophageal echocardiography, one-lung ventilation, cardiac rhythm device management, and pressor management is crucial for optimal anesthetic care., (© 2013 Elsevier Inc. All rights reserved.)

Aim: To evaluate the clinicopathological features and treatment outcomes of cap polyposis in the pediatric population., Methods: All pediatric patients with histologically proven diagnosis of cap polyposis were identified from our endoscopy and histology database over a 12 year period from 2000-2012 at our tertiary pediatric center, KK Women's and Children's Hospital in Singapore. The case records of these patients were retrospectively reviewed. The demographics, clinical course, laboratory results, endoscopic and histopathological features, treatments, and outcomes were analyzed. The study protocol was approved by the hospital institutional review board. The histological slides were reviewed by a pediatric histopathologist to confirm the diagnosis of cap polyposis., Results: Eleven patients were diagnosed with cap polyposis. The median patient age was 13 years (range 5-17 years); the sample included 7 males and 4 females. All of the patients presented with bloody stools. Seven patients (63%) had constipation, while 4 patients (36%) had diarrhea. All of the patients underwent colonoscopy and polypectomies (excluding 1 patient who refused polypectomy). The macroscopic findings were of polypoid lesions covered by fibrinopurulent exudates with normal intervening mucosa. The rectum was the most common involvement site (n = 9, 82%), followed by the rectosigmoid colon (n = 3, 18%). Five (45%) patients had fewer than 5 polyps, and 6 patients (65%) had multiple polyps. Histological examination of these polyps showed surface ulcerations with a cap of fibrin inflammatory exudate. Four (80%) patients with fewer than 5 polyps had complete resolution of symptoms following the polypectomy. One patient who did not consent to the polypectomy had resolution of symptoms after being treated with sulphasalazine. All 6 patients with multiple polyps experienced recurrence of bloody stools on follow-up (mean = 28 mo)., Conclusion: Cap polyposis is a rare and under-recognised cause of rectal bleeding in children. Our study has characterized the disease phenotype and treatment outcomes in a pediatric cohort.

Purpose: To evaluate the diagnostic accuracy of preoperative serum alpha-fetoprotein (AFP) levels in predicting malignancy risk in children and adolescents presenting with ovarian neoplasms., Methods: In 110 girls aged 18 and below diagnosed with ovarian neoplasms, we retrospectively correlated preoperative serum AFP levels with histological diagnosis of germ cell tumor or immature teratoma (GCT/IT) versus non-GCT/IT, and benign versus non-benign. We determined area under receiver-operating characteristic curves (AUC), sensitivity, specificity, and likelihood ratios., Results: Twenty patients (18.2 %) had non-benign ovarian neoplasms, of which 12 had GCT/IT (10.9 %). In diagnosing GCT/IT versus non-GCT/IT, specificity of preoperative serum AFP was 87.8 %, sensitivity 66.7 %, and AUC 0.853. Excluding infants to remove the effects of increased variance in AFP in this group, specificity improved (92.0 %), but not sensitivity (66.7 %); AUC was 0.926. Increasing AFP cutoff to two times upper normal limit improved specificity (94.9 %), but not sensitivity (66.7 %). For benign versus non-benign tumors, AFP specificity was only 88.9 % and sensitivity 50.0 %., Conclusion: The diagnostic accuracy of preoperative serum AFP for detecting GCT/IT in girls was limited by poor sensitivity and positive predictive value. Excluding infants and raising cutoff levels improved specificity marginally. Clinicians should be aware of these limitations when using AFP in the preoperative evaluation of childhood ovarian neoplasms.

Aim: Transanal endorectal pull-through (TERPT) has become popular for single-stage treatment of Hirschsprung's disease. The benefits of TERPT over the conventional transabdominal approach (TAB) are still unclear. We performed a comprehensive meta-analysis comparing the clinical outcomes of TERPT and TAB., Methods: Original articles published from 1998 to 2012 were searched from Medline, Embase, and Cochrane databases. Randomized controlled trials (RCT) and observational clinical studies (OCS) comparing TERPT and TAB were included. Outcomes evaluated included operative time, hospital stay and incidence of postoperative incontinence/soiling, constipation and enterocolitis. Pooled odds ratios (OR) were calculated for dichotomous variables; pooled mean differences (MD) were measured for continuous variables., Results: Of 93 studies, 1 RCT and 11 OCS were included, comprising 444 cases of TERPT and 348 cases of TAB (215 Soave, 94 Duhamel, 24 Swenson, 15 Rehbein procedures). TERPT had shorter operative time (MD=-57.85 min; 95% confidence interval [CI], -83.11 to -32.60; P<0.00001) and hospital stay (MD=-7.06 days; 95% CI, -10.95 to -3.16; P=0.0004). TERPT had less postoperative incontinence/soiling (OR=0.58; 95% CI 0.37-0.90; P=0.01) and constipation (OR=0.49; 95% CI 0.30-0.81; P=0.005). There was no difference in incidence of postoperative enterocolitis., Conclusion: TERPT is superior to TAB in operative time, hospital stay, postoperative incontinence and constipation. However, more randomized controlled trials are necessary to verify the benefit of TERPT for Hirschsprung's disease., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: The clinical utility of focused transthoracic echocardiography (TTE) is increasingly recognized in perioperative medicine. However its use is limited among anesthesiologists because of a lack of training. The most efficient training methods have not been determined. We hypothesized that simulation-based TTE training would be more effective than traditional lecture-based methods for teaching basic TTE skills to the anesthesiology residents., Methods: In this prospective randomized study, 61 anesthesiology residents (in anesthesia clinical training years 1 to 3) were randomized to either control (n = 30) or simulation groups (n = 31) for TTE training. A standardized pretest was administered before TTE training sessions of 45 minutes each. The first training session used a lecture-based video didactic in the control group or a TTE simulator in the simulation group. Comprehension in both groups was then assessed using a written posttest and by performing a TTE examination on a volunteer subject. TTE examinations were graded on the ability to acquire the correct image, image quality, anatomy identification, and time required to attain proper imaging by 2 blinded experts. A second training session incorporating "hands-on" training with a volunteer subject was conducted in a subset of 21 residents (n = 11 control, n = 10 simulation). The simulation group included additional simulator training. After the second session, another posttest on a volunteer subject was administered., Results: Pretest scores revealed similar preintervention knowledge among residents (56.0% ± 11.9% vs 59.3% ± 11.0%, P = 0.25; control versus simulator group, respectively). The simulation group scored higher on all criteria after the first training session: written posttest (57.9% ± 8.8% vs 68.2% ± 10.1%; P < 0.001), volunteer subject posttest image quality scores (0 to 25 scale) (6.4 ± 3.5 vs 12.4 ± 4.2; P = 0.003), anatomy identification scores (0 to 25 scale) (8.3 ± 6.6 vs 17.8 ± 6.6; P = 0.003), and percentage correct views (50 ± 19 vs 78 ± 21; P < 0.001). After the second session, all scores were again improved in the simulation group: volunteer subject posttest image quality scores (9.6 ± 3.3 vs 15.6 ± 2.8; P = 0.002), anatomy identification scores: (17.6 ± 3.8 vs 22.8 2.4; P = 0.003), and percentage correct views (80 ± 16 vs 96 ± 8; P = 0.007)., Discussion: This prospective randomized study demonstrated that anesthesiology residents trained with simulation acquired better skills in TTE image acquisition and anatomy identification on volunteer subjects. The educational benefit of simulation persisted even with introduction of hands-on instruction with volunteer subjects in both groups. The impact of these short-term educational approaches on longer-term retention and actual clinical application warrants further investigation.

Purpose: This study aimed to develop and provisionally validate a novel scoring index for preoperative cancer-risk prediction in childhood ovarian tumors., Methods: Fifty-five girls aged 18 and below underwent surgery for ovarian masses between 2004 and 2009. Benign or non-benign histological diagnoses (the latter including all malignant and borderline tumors and tumors containing immature components) were correlated with clinical and biochemical parameters, and blinded scores of ultrasound and computed-tomography using multivariate logistic regression. Regression coefficients were used as weighting factors to create an additive index. This index was validated prospectively against 23 consecutive adnexal masses operated in 2010., Results: In total, 67 tumors were benign and 11 non-benign. Non-benign diagnosis was independently associated with the maximum diameter of the largest solid component (score = value in cm), the presence of sex hormone-related symptoms (score = +6), and enhancement or flow in a septum or solid papillary projection (score = +4). The novel scoring index was calculated as the total score of these three parameters. A cutoff score of 7 gave a specificity of 97.9% and sensitivity of 87.5% for the training data set, and specificity and sensitivity of 100% for the pilot testing set., Conclusion: The novel pediatric risk-of-malignancy index is able to accurately discriminate between benign and non-benign ovarian tumors in children and adolescents. Its preoperative application may guide surgical management decisions before the availability of histological confirmation.

The clinical hallmark of neuroblastoma is heterogeneity. Biologically, ploidy and N-Myc amplification are currently the only 2 features used to define risk group and to determine therapy. Tyrosine kinase neurotrophin receptors (Trks, including TrkA, TrkB, and TrkC) are important in the clinical and biological behavior of neuroblastomas. The authors aim to study Trks gene expression in their local population of advanced neuroblastoma patients. Multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) assay on the expression of TrkA, TrkB, TrkB-truncated, and TrkC was performed on a total of 19 advanced neuroblastoma archival tumors, diagnosed in KK Women's and Children's Hospital between 2003 and 2007. Of the 19 tumors investigated, Trks expression was present in 14 (73.6%) cases. Of these cases, 8 (42.1%), 10 (52.6%), 7 (36.8%), and 6 (31.6%) expressed TrkA, TrkB, TrkB-truncated, and TrkC receptor mRNAs, respectively. Subsequently, the authors compared Trks expression with N-Myc amplification status of the 19 patients. N-Myc was amplified in 5 (26.3%) of the cases. Within the non-N-Myc-amplified group, Trks expression was present in 9 (64%) of the 14 cases. The significant expression of Trk isoforms among advanced neuroblastoma cases as evident from this study support their role as possible risk assessment tools alongside N-Myc amplification status.

Pathogenesis of cerebral ischemia has so far been described in the context of proteins and the pathways that they regulate. The discovery of biomarkers has also been focussed mainly on proteins and to some extent on the mRNAs that encode them. The knowledge on the role of microRNAs in understanding the pathogenesis of cerebral ischemia is still at its infancy. In this study, using rat models subjected to middle cerebral artery occlusion, we have profiled the microRNAs at different reperfusion times (0 to 48 h) to understand the progression of cerebral ischemia. We have also attempted to correlate the expression of microRNAs to treatment with an NMDA antagonist (MK801) and to protein expression with the hope of demonstrating the potential use of microRNAs as early biomarkers of stroke.

In recent years, increased interest has been directed towards hydrogen sulfide (H2S) as the third gasotransmitter and its role in various diseases. Cystathionine-gamma-lyase (CSE) is one of the enzymes responsible for the endogenous production of H2S in mammals. With the aid of the crystal structures of human CSE and site-directed mutagenesis studies, we have identified several amino acid residues in CSE that are actively involved in the catalysis of H2S production. Contrary to reports suggesting that Tyr114 is required for substrate binding, our results reveal a significant increase in the production of H2S upon mutation of Tyr114 to phenylalanine. This is attributed to an increased rate of pyridoxal 5'-phosphate (PLP) regeneration due to weakened pi-stacking interactions between Phe114 and PLP. Thr189 is also identified as a crucial residue where hydrogen bonding to Asp187 keeps the latter in an optimal position for hydrogen bonding to the pyridoxal nitrogen of PLP. Furthermore, mutation of Glu339 to lysine, alanine or tyrosine reveals the importance of the hydrophobicity of the 339th amino acid in determining the specificity of the enzyme for the catalysis of alpha,gamma-elimination or alpha,beta-elimination reaction. Our study also shows that the rate of H2S production is increased with increasing exogenous PLP concentration, hence supporting our hypothesis that apo-CSE is formed during the catalysis of H2S production. Taken together, these findings suggest novel routes towards the design of activators or inhibitors that modulate the production of H2S; these modulators may also serve as lead compounds in the development of drugs or mechanistic probes in the study of various H2S-related diseases., (Copyright (c) 2009. Elsevier Ltd. All rights reserved.)

Objective: To investigate social, clinical, and disease-related factors associated with diagnostic delay., Materials and Methods: Two-hundred and 9 solid tumor cases reported to the Singapore Childhood Cancer Registry at KK Hospital between 1997 and 2007 were reviewed retrospectively. The natural logarithms of total delay times were correlated with social, clinical, and disease factors using univariate and multivariate analysis. Subanalysis was performed for the periods before and after first healthcare contact, which were defined as parental and physician delay, respectively., Results: Mean total delay was 11.6 weeks. Mean parental and physician delay was 7.7 and 4.0 weeks, respectively. Shorter delay was associated with younger age (P<0.05), incidental detection by healthcare workers (P<0.001), and first presentations to pediatricians and nonpediatric emergency departments (P=0.01). Tumor type (P<0.01) and site (P=0.001) were also significantly related. After adjustment for other factors, extracranial germ cell tumors, abdominal tumors and first presentation to nonpediatric emergency departments were significantly associated with shorter total delay. Disease stage remained constant over time, with 30% presenting in stage 4., Conclusions: Patient age, first healthcare contact, tumor type, and site were significantly related to diagnostic delay in pediatric solid tumors. Our findings reflect factors related to delay in an urban island-state with minimized confounding by healthcare access and geographic factors.

Arrays of highly ordered silicon nanowire (SiNW) clusters are fabricated using complementary metal-oxide semiconductor (CMOS) field effect transistor-compatible technology, and the ultrasensitive, label-free, electrical detection of cardiac biomarker in real time using the array sensor is presented. The successful detection of human cardiac troponin-T (cTnT) has been demonstrated in an assay buffer solution of concentration down to 1 fg/mL, as well as in an undiluted human serum environment of concentration as low as 30 fg/mL. The high specificity, selectivity, and swift response time of the SiNWs to the presence of ultralow concentrations of a target protein in a biological analyte solution, even in the presence of a high total protein concentration, paves the way for the development of a medical diagnostic system for point-of-care application that is able to provide an early and accurate indication of cardiac cellular necrosis.

MicroRNA (miRNA), an 18-24-nucleotide (nt) noncoding RNA molecule in the genes of humans, plants and animals, is emerging as a key player in gene regulation. As a result, label-free, rapid, and sensitive detection for miRNA is of great significance. In this work, a label-free and direct hybridization assay for ultrasensitive detection of miRNA using silicon nanowires (SiNWs) device has been developed. Peptide nucleic acids (PNAs), which serve as a receptor to recognize miRNA directly without labeling the target miRNA, are immobilized on the surface of the SiNW device. Resistance change measured before and after hybridization correlates directly to concentrations of the hybridized target miRNA. Concentration-dependent measurements indicate that a detection limit of 1 fM was obtained using the optimized assay. The technique enables identification of fully matched versus mismatched miRNA sequences. Furthermore, the SiNW device is capable of detecting miRNA in total RNA extracted from Hela cells. This approach paves a way for label-free, early detection of miRNA as a biomarker in cancer diagnostics with very high sensitivity and good specificity.

MicroRNAs (miRNAs) belong to the group of non-coding, small RNAs (19 to 21 nucleotide-long oligonucleotides) that are endogenously produced from their own genes. miRNAs interfere with or affect the transcription or translation of other genes, resulting in gene silencing or activation by a process known as RNAi or RNA activation, respectively. The discovery of miRNAs and related small RNAs within the last 10 years has opened up a new field in biology, called RNomics, which investigates differences in RNA populations and offers great potential in correcting the regulation of abnormally expressed and disease-causing genes, as well as in the development of novel therapeutic agents. This review focuses on the developments in miRNAs and their potential therapeutic applications.

The highly sensitive and sequence-specific detection of single-stranded oligonucleotides using nonoxidized silicon nanowires (SiNWs) is demonstrated. To maximize device sensitivity, the surface of the SiNWs was functionalized with a densely packed organic monolayer via hydrosilylation, subsequently immobilized with peptide nucleic acid (PNA) capable of recognizing the label-free complementary target DNA. Because of the selective functionalization of the SiNWs, binding competition between the nanowire and the underlying oxide is avoided. Transmission electron microscopy was conducted to clearly differentiate the SiNW surface before and after removal of SiO(2). Fluorescence microscopy was used to further realize the selectivity of the oxide-etched chemistry on the SiNWs and sequence specificity of PNA-DNA hybridization. The concentration-dependent resistance change measurements upon hybridization of PNA-DNA show that detection limit down to 10fM can be obtained. The SiNW devices also reveal the capability of an obvious discrimination against mismatched sequences. Among several efforts being made to improve detection sensitivity, this work addresses one significant issue regarding surface functionalization which enables highly sensitive biomolecular sensing with SiNWs.

To provide a comprehensive understanding of the field effect in silicon nanowire (SiNW) sensors, we take a systematic approach to fine tune the distance of a charge layer by controlling the hybridization sites of DNA to the SiNW preimmobilized with peptide nucleic acid (PNA) capture probes. Six target DNAs of the same length, but differentiated successively by three bases in the complementary segment, are hybridized to the PNA. Fluorescent images show that the hybridization occurs exclusively on the SiNW surface between the target DNAs and the PNA. However, the field-effect response of the SiNW sensor decreases as the DNA (charge layer) moves away from the SiNW surface. Theoretical analysis shows that the field effect of the SiNW sensor relies primarily on the location of the charge layer. A maximum of 102% change in resistance is estimated based on the shortest distance of the DNA charge layer (4.7 A) to the SiNW surface.

Objective: The "Chinese Fan Spread" (CFS) distraction technique for laparoscopic reduction of intussusception is herein described and its outcome and benefits are evaluated., Methods: A retrospective review was performed of all patients who underwent attempts at laparoscopic reduction of intussusception at our center. The CFS distraction technique was consistently applied in all cases., Results: Fourteen patients were identified. Median age was 2.4 years (range, 4 months to 10.3 years). Indications for surgery included (1) failed pneumatic reduction (n=11), (2) need to evaluate for lead point in a patient with 4 recurrences (n=1), (3) need to biopsy the lead point in a patient with suspected lymphoma (n=1), and (4) diagnostic laparoscopy for evaluation of hematochezia (n=1). Two patients who failed laparoscopic reduction by the CFS distraction technique also failed open manual reduction, requiring right hemicolectomy. Of the 12 (86%) who were successfully reduced laparoscopically, pathologic lead points were identified in 5 (2 acute appendicitis, 1 Meckel's diverticulum, 1 harmatomatous polyp, and 1 Burkitt's lymphoma). Lead points were excised laparoscopically or via a vertical transumbilical incision. There were no complications., Conclusion: Laparoscopic reduction of intussusception by the CFS distraction technique is effective and safe. Lead points may be dealt with together either laparoscopically or via a transumbilical incision.

Background: Despite routine use of air enema reduction in childhood intussusceptions, some still require operative management. This study evaluated the role of surgery and identified factors associated with failed air enema reduction and bowel resection., Methods: We reviewed 24 patients who underwent laparotomies for intussusception between 1 July 1999 and 31 July 2002. Demographic data, clinical presentations, investigations, surgical interventions and their outcomes were reviewed., Results: Twenty-four (14.5%) of 166 patients treated for intussusceptions between 1 July 1999 and 31 July 2002 underwent laparotomies. A significant proportion (45.8%) was younger than 3 months and older than 36 months of age. Intussusception was diagnosed on ultrasonography in 21 patients. Eighteen underwent attempted air enema reduction. Ileocolic intussusceptions occurred in 54.2% of patients. Five patients had small bowel intussusceptions, all of whom required bowel resection. Seven patients (29.2%) had pathological lead points. Presence of pathological lead points and intussusceptions occurring outside the ileocolic region strongly predicted the need for bowel resection., Conclusion: Air enema reductions are less likely to succeed in patients less than 3 months old and those more than 3 years old. Bowel resection is most likely required when pathological lead points are present and when intussusceptions occur outside the ileocolic region. Early surgical intervention may obviate the need for bowel resection in selected patients, thereby reducing surgical morbidity.

Background/purpose: We aim to justify the need for surgical intervention in our patients with childhood small bowel intussusceptions (SBIs) and review the current concepts in childhood SBI., Materials and Methods: We retrospectively reviewed the clinical charts of all patients with surgically confirmed SBI between July 1999 and October 2002. Demographic data, clinical presentation and investigations, operative and pathologic findings, and outcome were analyzed., Results: Of 173 patients with intussusception, 6 (3.5%) were diagnosed with SBI. Median age was 11 months. Ultrasonography revealed intussusceptions in all patients, but only 1 was diagnosed with SBI. Air enema reductions were attempted in 4 of 6 patients with all ending up in failure and surgery. Surgery revealed ileoileal intussusceptions in 4 patients and jejunojejunal intussusceptions in 2 patients. Two patients had long intussusceptions measuring between 30 and 50 cm in length. Five patients had pathologic lead points, and bowel complications occurred in 2 patients. All underwent bowel resection and primary anastomosis., Conclusion: Despite reports on spontaneous reduction of SBI, surgery was unavoidable in all our patients with SBI because of the presence of pathologic lead points and/or bowel complications. Air enema reduction was ineffective in SBI. Due caution should be exercised when selecting patients for expectant management.

Introduction: Fetus-in-fetu is an extremely rare condition in which a malformed fetus is found in the body of its twin. To our knowledge, fewer than 100 cases have been reported. Wide variations of presentation have been described, although its embryo-pathogenesis and differentiation from a teratoma have not been well established., Clinical Picture: We describe a male neonate with a fetoid-like mass in his pelvis associated with bilateral undescended testes. The mass was detected on prenatal ultrasound scans. The diagnosis of fetus-in-fetu was considered prenatally and confirmed on a computed tomography scan after birth., Outcome: The mass was successfully excised. Histological examination, accompanied by a review of the literature, confirmed that the mass had features consistent with a fetus-in-fetu., Conclusions: Although an extremely rare clinical entity, fetus-in-fetu can be diagnosed prior to surgery with current imaging modalities. When it arises in the retroperitoneum of a male infant, it can hinder the descent of the testes. Complete excision is curative.

Silica-incorporated aluminum (RHA-Al) was synthesized from rice husk ash (RHA) using the sol-gel technique. RHA-Al was calcined at 500 degrees C for 5 h to yield RHA-Al(C). The ratio of silica to alumina was found to be 4:1. The BET analysis of RHA-Al(C) showed an increase in total pore volume and specific surface area compared to RHA-Al. SEM and XRD showed that RHA-Al and RHA-Al(C) were composed of microcrystals and the surface of both samples had a porous structure. Adsorption studies of palmytic acid on RHA-Al and RHA-Al(C) at 30, 40, and 50 degrees C conformed to the Langmuir isotherm. The equilibrium parameter, R, revealed that both are good adsorbents for palmytic acid. The Gibbs free energy of adsorption, DeltaG(ads)(0), was determined to be between -21.0 and -26.0 kJ mol(-1). DeltaH(ads)(0) and DeltaS(ads)(0) for RHA-Al were found to be 26.2 kJ mol(-1) and 158 J mol(-1), respectively. Corresponding values for RHA-Al(C) were 31.7 kJ mol(-1) and 178 J mol(-1). The adsorption of fatty acid on RHA-Al and RHA-Al(C) was an endothermic process, which occurred spontaneously. An FTIR study on the adsorbed material was used to determine the possible adsorbed complex on the surface of the adsorbent.