A Collagen10a1 mutation disrupts cell polarity in a medaka model for metaphyseal chondrodysplasia type Schmid

Heterozygous mutations in COL10A1 lead to metaphyseal chondrodysplasia type Schmid (MCDS), a skeletal disorder characterized by epiphyseal abnormalities. Prior analysis revealed impaired trimerization and intracellular retention of mutant collagen type X alpha 1 chains as cause for elevated endoplasmic reticulum (ER) stress. However, how ER stress translates into structural defects remained unclear. We generated a medaka (Oryzias latipes) MCDS model harboring a 5 base pair deletion in col10a1, which led to a frameshift and disruption of 11 amino acids in the conserved trimerization domain. col10a1Δ633a heterozygotes recapitulated key features of MCDS and revealed early cell polarity defects as cause for dysregulated matrix secretion and deformed skeletal structures. Carbamazepine, an ER stress-reducing drug, rescued this polarity impairment and alleviated skeletal defects in col10a1Δ633a heterozygotes. Our data imply cell polarity dysregulation as a potential contributor to MCDS and suggest the col10a1Δ633a medaka mutant as an attractive MCDS animal model for drug screening.

Bariatric Surgeon Ergonomics: A Comparison of Laparoscopy and Robotics

INTRODUCTION

Bariatric surgery is routinely performed using laparoscopic and robotic approaches. Musculoskeletal injuries are prevalent among both robotic and laparoscopic bariatric surgeons. Studies evaluating ergonomic differences between laparoscopic and robotic bariatric surgery are limited. This study aims to analyze the ergonomic, physical, and mental workload differences among surgeons performing robotic and laparoscopic bariatric surgery.

MATERIALS AND METHODS

All primary laparoscopic and robotic bariatric surgeries, Roux-en-Y gastric bypass, and sleeve gastrectomy between May and August 2022 were included in this study. Objective ergonomic analysis was performed by an observer evaluating each surgeon intraoperatively according to the validated Rapid Entire Body Assessment tool, with a higher score indicating more ergonomic strain. After each operation, surgeons subjectively evaluated their physical workload using the body part discomfort scale, and their mental workload using the surgery task load index.

RESULTS

Five bariatric surgeons participated in this study. In total, 50 operative cases were observed, 37 laparoscopic and 13 robotic. The median total Rapid Entire Body Assessmentscore as a primary surgeon was significantly higher in laparoscopic (6.0) compared to robotic (3.0) cases (P < 0.01). The laparoscopic and robotic approaches had no significant differences in the surgeons' physical (body part discomfort scale) or mental workload (surgery task load index).

CONCLUSIONS

This study identified low-risk ergonomic stress in surgeons performing bariatric surgery robotically compared to medium-risk stress laparoscopically. Since ergonomic stress can exist even without the perception of physical or mental stress, this highlights the importance of external observations to optimize ergonomics for surgeons in the operating room.

Inpatient opioid use and pain control after robotic versus laparoscopic sleeve gastrectomy

BACKGROUND

During the past decade, the proportion of bariatric surgery performed robotically has been rising. However, the clinical benefits of the robotic approach over laparoscopy are uncertain. One area in need of further investigation is pain control after robotic versus laparoscopic bariatric surgery.

METHODS

A retrospective cohort study was conducted of bariatric surgery patients undergoing laparoscopic or robotic sleeve gastrectomy at a single institution from October 2019 to August 2022. Inpatient opioid use was measured in morphine milliequivalents. Pain scores were collected by the nursing staff.

RESULTS

A total of 368 patients were included: 286 laparoscopic and 82 robotic surgery patients. The groups shared similar demographics. For the entire cohort, the mean age was 42 years, the body mass index was 50 kg/m2, and 79% were female. Mean operative time was significantly lower for laparoscopic surgeries (87.5 ± 47.3 minutes vs 109.3 ± 30.3 minutes; P < .01). The median total inpatient morphine milligram equivalents used was similar for both groups: 52.3 (31.5-77.0) for the laparoscopic group versus 40 (24-74.5) for robotic (P = .13). Mean postoperative pain scores (scale out of 10) were not significantly different between groups: 5.2 ± 1.7 (postoperative day 0) and 4.5 ± 1.7 (day 1) for laparoscopic patients versus 5.1 ± 2.0 (day 0) and 4.4 ± 1.8 (day 1) for robotic. The proportion of patients prescribed opioids at discharge was significantly higher for the laparoscopic group (75.2% vs 62.2%; P = .02). Other clinical outcomes, including duration of stay, 30-day readmissions, and visits to the emergency department, were not significantly different.

CONCLUSION

There is no difference in inpatient opioid use or pain scores between patients undergoing laparoscopic and robotic sleeve gastrectomy.

Lineage Tracing of Bone Cells in the Regenerating Fin and During Repair of Bone Lesions

Small teleost fishes such as zebrafish and medaka show remarkable regeneration capabilities upon tissue injury or amputation. To elucidate cellular mechanisms of teleost tissue repair and regeneration processes, the Cre/LoxP recombination system for cell lineage tracing is a widely used technique. In this chapter, we describe protocols used for inducible Cre/LoxP recombination-mediated lineage tracing of osteoblast progenitors during medaka fin regeneration as well as during the repair of osteoporosis-like bone lesions in the medaka vertebral column. Our approach can be adapted for lineage tracing of other cell populations in the regenerating teleost fin or in other tissues undergoing repair.

Characterization of Fibrodysplasia Ossificans Progessiva relevant Acvr1/Acvr2 Activin receptors in medaka (Oryzias latipes)

Activin and Bone Morphogenetic Protein (BMP) signaling plays crucial roles in vertebrate organ formation, including osteo- and angiogenesis, and tissue homeostasis, such as neuronal maintenance. Activin and BMP signaling needs to be precisely controlled by restricted expression of shared receptors, stoichiometric composition of receptor-complexes and presence of regulatory proteins. A R206H mutation in the human (hs) BMP type I receptor hsACVR1, on the other hand, leads to excessive phosphorylation of Sons of mothers against decapentaplegic (SMAD) 1/5/8. This in turn causes increased inflammation and heterotopic ossification in soft tissues of patients suffering from Fibrodysplasia Ossificans Progressiva (FOP). Several animal models have been established to understand the spontaneous and progressive nature of FOP, but often have inherent limitations. The Japanese medaka (Oryzias latipes, ola) has recently emerged as popular model for bone research. To assess whether medaka is suitable as a potential FOP animal model, we determined the expression of Activin receptor type I (ACVR1) orthologs olaAcvr1 and olaAcvr1l with that of Activin type II receptors olaAcvr2ab, olaAcvr2ba and olaAcvr2bb in embryonic and adult medaka tissues by in situ hybridization. Further, we showed that Activin A binding properties are conserved in olaAcvr2, as are the mechanistic features in the GS-Box of both olaAcvr1 and olaAcvr1l. This consequently leads to FOP-typical elevated SMAD signaling when the medaka type I receptors carry the R206H equivalent FOP mutation. Together, this study therefore provides experimental groundwork needed to establish a unique medaka model to investigate mechanisms underlying FOP.

[Genetic diagnosis of microcephaly]

Objective: To explore the diagnostic value of chromosome karyotype analysis, chromosomal microarray analysis (CMA) and whole exome sequencing (WES) in microcephaly. Methods: A total of 9 cases of microcephaly fetuses diagnosed by prenatal ultrasound or children with microcephaly diagnosed after birth were selected from the Sixth Affiliated Hospital of Guangzhou Medical University from January 2014 to August 2022.Karyotype analysis and/or CMA were used to detect. The cases with negative karyotype analysis and CMA results were further sequenced by trio-based WES (Trio-WES). Then the coding genes contained in the pathogenic copy number variation (CNV) fragments were analyzed by gene ontology (GO) enrichment. The genes related to the development of the central nervous system contained in the pathogenic CNV and the pathogenic genes found by Trio-WES were combined for gene interaction network analysis. Results: In this study, 9 cases of microcephaly were recruited, with the time of diagnosis ranged from 23 weeks of gestation to 7 years after birth, and the head circumference of fetus or children ranged from 18.3 to 42.5 cm (-7SD to -2SD). Karyotype analysis was detected in all 9 cases and no abnormality result was found. Eight cases were detected by CMA, and one abnormal was found. Five cases were detected by Trio-WES, and two cases were detected with likely pathogenic genes. The GO enrichment analysis of the coding gene in the 4p16.3 microdeletion (pathogenic CNV) region showed that: in biological process, it was mainly concentrated in phototransduction, visible light; in terms of molecular function, it was mainly concentrated in fibroblast growth factor binding; in terms of cell components, it was mainly concentrated in rough endoplasmic reticulum. Gene interaction network analysis suggested that CDC42 gene could interact with CTBP1, HTT and ASPM gene. Conclusions: CMA could be used as a first-line detection technique for microcephaly. When the results of chromosome karyotype analysis and/or CMA are negative, Trio-WES could improve the detection rate of pathogenicity of microcephaly.

[Prenatal genetic diagnosis of the fetuses with isolated corpus callosum abnormality]

Objective: To explore the application value of chromosome karyotype analysis, chromosomal microarray analysis (CMA) and whole exome sequencing (WES) in prenatal diagnosis of isolated corpus callosum abnormality (CCA) fetus. Methods: Fetuses diagnosed with isolated CCA by ultrasound and MRI and receiving invasive prenatal diagnosis in Guangzhou Women and Children's Medical Center and Qingyuan People's Hospital from January 2010 to April 2021 were selected. Karyotype analysis and/or CMA [or copy number variation sequencing (CNV-seq)] were performed on all fetal samples, and WES was performed on fetal samples and their parents whose karyotype analysis and/or CMA (or CNV-seq) results were not abnormal. Results: Among 65 fetuses with isolated CCA, 38 cases underwent karyotype analysis, and 3 cases were detected with abnormal karyotypes, with a detection rate of 8% (3/38). A total of 49 fetuses with isolated CCA underwent CMA (or CNV-seq) detection, and 6 cases of pathogenic CNV were detected, the detection rate was 12% (6/49). Among them, the karyotype analysis results were abnormal, and the detection rate of further CMA detection was 1/1. The karyotype results were normal, and the detection rate of further CMA (or CNV-seq) detection was 14% (3/21). The detection rate of CMA as the first-line detection technique was 7% (2/27). A total of 25 fetuses with isolated CCA with negative results of karyotyping and/or CMA were tested by WES, and 9 cases (36%, 9/25) were detected with pathogenic genes. The gradient genetic diagnosis of chromosomal karyotyping, CMA and WES resulted in a definite genetic diagnosis of 26% (17/65) of isolated CCA fetuses. Conclusions: Prenatal genetic diagnosis of isolated CCA fetuses is of great clinical significance. The detection rate of CMA is higher than that of traditional karyotyping. CMA detection could be used as a first-line detection technique for fetuses with isolated CCA. WES could increase the pathogenicity detection rate of fetuses with isolated CCA when karyotype analysis and/or CMA test results are negative.

A non-disruptive and efficient knock-in approach allows fate tracing of resident osteoblast progenitors during repair of vertebral lesions in medaka

During bone development and repair, osteoblasts are recruited to bone deposition sites. To identify the origin of recruited osteoblasts, cell lineage tracing using Cre/loxP recombination is commonly used. However, a confounding factor is the use of transgenic Cre drivers that do not accurately recapitulate endogenous gene expression or the use of knock-in Cre drivers that alter endogenous protein activity or levels. Here, we describe a CRISPR/Cas9 homology-directed repair knock-in approach that allows efficient generation of Cre drivers controlled by the endogenous gene promoter. In addition, a self-cleaving peptide preserves the reading frame of the endogenous protein. Using this approach, we generated col10a1p2a-CreERT2 knock-in medaka and show that tamoxifen-inducible CreERT2 efficiently recombined loxP sites in col10a1 cells. Similar knock-in efficiencies were obtained when two unrelated loci (osr1 and col2a1a) were targeted. Using live imaging, we traced the fate of col10a1 osteoblast progenitors during bone lesion repair in the medaka vertebral column. We show that col10a1 cells at neural arches represent a mobilizable cellular source for bone repair. Together, our study describes a previously unreported strategy for precise cell lineage tracing via efficient and non-disruptive knock-in of Cre.

In-vitro anti-diabetic activity and in-silico studies of binding energies of palmatine with alpha-amylase, alpha-glucosidase and DPP-IV enzymes

Palmatine a protoberberine alkaloid has been previously reported to possess in vivo antidiabetic and antioxidant property. The aim of the experiment is to evaluate the in vitro antidiabetic activity and in-silico studies of the binding energies of Palmatine, acarbose, and Sitagliptin with the three enzymes of alpha-amylase, alpha-glucosidase, and dipeptidyl peptidase-IV (DPP-IV). The in vitro antidiabetic study was done by evaluating the inhibitory effect of palmatine on the activities of alpha-amylase, alpha-glucosidase, and DPP-IV. Acarbose, and sitagliptin was used as standard drug. The molecular docking study was performed to study the binding interactions of palmatine with alpha-glucosidase, a-amylase, and DPP-IV. The binding interactions were compared with the standard compounds Sitagliptin and acarbose. Palmatine with IC50 (1.31 ± 0.27 µM) showed significant difference of (&lt; 0.0001) higher inhibiting effect on alpha-amylase and weak inhibiting effect on alpha-glucosidase enzyme with IC50 (9.39 ± 0.27 µM) and DPP-IV with IC50 (8.7 ± 1.82 µM). Palmatine possess inhibition effect on the three enzymes.

Macrophages Switch to an Osteo-Modulatory Profile Upon RANKL Induction in a Medaka (Oryzias latipes) Osteoporosis Model

In mammals, osteoclasts differentiate from macrophages in the monocyte lineage. Although many factors driving osteoclast formation are known, the detailed processes underlying precursor recruitment, differentiation, and interaction of macrophages with other cell types involved in bone remodeling are poorly understood. Using live imaging in a transgenic medaka osteoporosis model, where ectopic osteoclasts are induced by RANKL expression, we show that a subset of macrophages is recruited to bone matrix to physically interact with bone-forming osteoblast progenitors. These macrophages subsequently differentiate into cathepsin K- (ctsk-) positive osteoclasts. One day later, other macrophages are recruited to clear dying osteoclasts from resorbed bone by phagocytosis. To better understand the molecular changes underlying these dynamic processes, we performed transcriptome profiling of activated macrophages upon RANKL induction. This revealed an upregulation of several bone-related transcripts. Besides osteoclast markers, we unexpectedly also found expression of osteoblast-promoting signals in activated macrophages, suggesting a possible non-cell autonomous role in osteogenesis. Finally, we show that macrophage differentiation into osteoclasts is dependent on inflammatory signals. Medaka deficient for TNFα or treated with the TNFα-inhibitor pentoxifylline exhibited impaired macrophage recruitment and osteoclast differentiation. These results show the involvement of inflammatory signals and the dynamics of a distinct subset of macrophages during osteoclast formation. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Assessment of postoperative opioid stewardship using a novel electronic-based automated text and phone messaging platform

BACKGROUND

Practices of opioid prescribing vary widely across general surgery providers. The goal of this study was to use a text-based platform to assess postdischarge opioid utilization.

METHODS

A prospective, cohort study enrolled adult patients undergoing operations across the following 3 general surgery sections: minimally invasive surgery, colorectal, and surgical oncology. Using Epharmix, an electronic text-based platform, short message service text messages were sent to enrolled patients on postdischarge days 1 to 7, 14, 2, and 28 inquiring about the number of opioid pills taken since discharge and pain medication refills.

RESULTS

A total of 253 patients enrolled and completed the intervention. Patient participation was robust, with 80% of patients responded to >50% of all text-based questions, and 64% responded to >80% of all questions. Patients undergoing bariatric surgery were prescribed the most narcotic pain medications (average milligram of morphine equivalents: 250.8), and those undergoing endocrine neck surgery the least (average milligram of morphine equivalent: 53.5). All surgical categories studied consumed ≤25% of their total prescribed milligram of morphine equivalents. Only 8 patients (3.2%) requested an opioid refill by postdischarge days 28.

CONCLUSION

A text-based platform can track reliably patients' opioid usage postdischarge. Such platforms may facilitate the development of data-driven, standardized practices of opioid prescribing matched to patients' anticipated opioid usage postdischarge.

Bioequivalence and pharmacokinetic comparison of two fixed dose combination of Metformin/ Glibenclamide formulations in healthy subjects under fed condition

AIM

This study is conducted to compare the pharmacokinetic profiles of two fixed dose combination of metformin/glibenclamide tablets (500mg/5 mg per tablet).

MATERIALS AND METHODS

This is a single-center, single-dose, open-label, randomized, 2-treatment, 2-sequence and 2- period crossover study with a washout period of 7 days. All 28 adult male subjects were required to fast for at least 10 hours prior to drug administration and they were given access to water ad libitum during this period. Thirty minutes prior to dosing, all subjects were served with a standardized high-fat and high-calorie breakfast with a total calorie of 1000 kcal which was in accordance to the EMA Guideline on the Investigation of Bioequivalence. Subsequently, subjects were administered either the test or reference preparation with 240mL of plain water in the first trial period. During the second trial period, they received the alternate preparation. Plasma levels of glibenclamide and metformin were analysed separately using two different high performance liquid chromatography methods.

RESULTS

The 90% confidence interval (CI) for the ratio of the AUC0-t, AUC0-∞, and Cmax of the test preparation over those of the reference preparation were 0.9693-1.0739, 0.9598- 1.0561 and 0.9220 - 1.0642 respectively. Throughout the study period, no serious drug reaction was observed. However, a total of 26 adverse events (AE)/side effects were reported, including 24 that were definitely related to the study drugs, namely giddiness (n=17), while diarrheoa (n=3), headache (n=2) and excessive hunger (n=2) were less commonly reported by the subjects.

CONCLUSION

It can be concluded that the test preparation is bioequivalent to the reference preparation.

Efficacy of robotic versus open transversus abdominis release in a porcine model

PURPOSE

Transversus abdominis muscle release (TAR) combines retromuscular mesh placement with posterior component separation and muscle release. TAR is usually an open technique for abdominal wall reconstruction; however, several centers have performed this operation robotically and claim better clinical outcomes when compared to open surgery. We sought to compare robotic versus open TAR utilizing a porcine model.

METHODS

Animals were randomized to open versus robotic TAR with mesh placement, survived for 4 weeks, then underwent diagnostic laparoscopy to assess adhesive burden and adhesion tenacity. T-peel testing was utilized to assess mesh ingrowth. The primary outcome was adhesive burden; secondary outcomes included mesh incorporation, contraction, and operative time.

RESULTS

Nine robotic and eight open TARs were performed. Mean operative time was significantly shorter for the open cases compared to robotic cases (88.6 ± 12.9 min versus 228.3 ± 46.2, p < 0.01). Operative time in the robotic arm of the study decreased over time, from 300 to 165 min. No difference was seen in the mean adhesion area between the two groups. Adhesion tenacity and mesh flatness were similar. The work required to peel the mesh off surrounding tissue was significantly higher in the open TAR than in the robotic TAR group: 52.6 ± 15.5 and 32.9 ± 10.6 mJ/cm2, respectively (p < 0.01).

CONCLUSIONS

There were no differences in adhesions between the robotic and open approaches, but greater mesh contraction and ingrowth was observed in the open TAR group. Though operative time was longer in the robotic group, time dropped by about 40% from the first case to the last.

Telomerase Expression in Medaka ( Oryzias melastigma) Pharyngeal Teeth

Nonmammalian vertebrates have the capacity of lifelong tooth replacement. In all vertebrates, tooth formation requires contact and interaction between the oral or pharyngeal epithelium and the underlying mesenchyme. To secure lifelong replacement, the presence of odontogenic stem cells has been postulated, particularly in the epithelial compartment. This study uses an advanced teleost fish species, the marine medaka Oryzias melastigma, a close relative to Oryzias latipes, to examine the expression and distribution of telomerase reverse transcriptase (Tert), the catalytic unit of telomerase, in developing pharyngeal teeth and to relate these data to the proliferative activity of the cells. The data are complemented by expression analysis of the pluripotency marker oct4 and bona fide stem cell marker lgr5. Tert distribution and tert expression in developing tooth germs show a dynamic spatiotemporal pattern. Tert is present first in the mesenchyme but is downregulated as the odontoblasts differentiate. In contrast, in the epithelial enamel organ, Tert is absent during early stages of tooth formation and upregulated first in ameloblasts. Later, Tert is expressed and immunolocalized throughout the entire inner enamel epithelium. The pattern of Tert distribution is largely mutually exclusive with that of proliferating cell nuclear antigen (PCNA) immunoreactivity: highly proliferative cells, as revealed by PCNA staining, are negative for Tert; conversely, PCNA-negative cells are Tert-positive. Only the early condensed mesenchyme is both Tert- and PCNA-positive. The absence of tert-positive cells in the epithelial compartment of early tooth germs is underscored by the absence of oct4- and lgr5-positive cells, suggesting ways other than stem cell involvement to secure continuous renewal.

Synthetic versus Biologic Mesh in Single-Stage Repair of Complex Abdominal Wall Defects in a Contaminated Field

BACKGROUND

Synthetic meshes have been used with varying rates of success in a contaminated setting, although their use is not widely accepted because of concerns for infection. A biologic mesh (BM) is assumed to be more resistant to infection than a synthetic mesh; however, sparse clinical data support this theory. The hypothesis for this study: Uncoated polypropylene synthetic mesh (USM) can be used to obtain a durable repair in the setting of a contaminated abdominal wall reconstruction (AWR) in a single-stage procedure with comparable infectious outcomes to a biologic mesh repair.

PATIENTS AND METHODS

We performed a retrospective chart review on contaminated AWR, comparing 34 BM with 24 USM with infection as the primary outcome of interest. Secondary outcomes were re-admission and re-operation. We also investigated the microbial isolates that were cultured.

RESULTS

Mesh groups were similar in their demographics, duration of surgery, previous mesh, surgical site class, and source of contamination. Length of stay was 4 d longer in BM, p = 0.01. Overall infection rate was 50% for BM vs. 29.2% for USM, p = 0.18. Treatment in case of infection was similar across both groups. Gram positive bacteria comprised 39% of BM microbiology vs. 63% for USM. Re-admission rate was 52.9% for BM versus 45.8% for USM, p > 0.5. The BMs re-admitted for surgical site infection/abdominal abscess were 38.9% versus 55.6% for USM. No USM were re-admitted for seroma versus 33.3% of BM, p = 0.06. Re-operation rate was 26.5% for BM versus 33.3% for USM, p > 0.5. Procedures performed at re-operation were similar between groups. Regression analysis did not demonstrate an association between mesh type and our outcomes.

CONCLUSION

Our results show that synthetic meshes are not inferior to biologic meshes in contaminated AWR. This is important in view of the tremendous cost disparity between these two products and the questionable ability of biologic mesh to offer a durable hernia repair.

Perioperative risk and complications of revisional bariatric surgery compared to primary Roux-en-Y gastric bypass

INTRODUCTION

Growing number of patients requires revisional bariatric surgery. This study compares perioperative course and outcomes of revisional versus primary bariatric surgery.

METHODS

Patients who underwent revisional bariatric surgery from Jan 1997 to Sept 2012 were reviewed retrospectively. Every revisional patient with BMI >35 and age <70 was matched with a primary Roux-en-Y gastric bypass control patient based on preoperative BMI, age, sex, and year of surgery. Patients' preoperative indications, intraoperative/postoperative course, and complications were analyzed.

RESULTS

Two hundred and fifty five patients underwent revisional bariatric surgery with resulting Roux-en-Y gastric bypass anatomy while 1,674 patients underwent primary gastric bypass in the same time interval. Of 255 patients, 172 patients were paired with 172 primary gastric bypass patients. Revisional bariatric group had preoperative BMI 48 ± 9, age 52 ± 9 years, 93 % female, 44 % laparoscopic, 30 % diabetic, 60 % hypertensive. Primary bypass patients had preoperative BMI 49 ± 8, age 52 ± 9 years, 93 % female, 97 % laparoscopic, 49 % diabetic, 67 % hypertensive. Compared to primary bypass patients, revisional patients had significantly higher estimated blood loss (463.7 vs. 113.3 mL), longer operative time (272.5 vs. 175.5 min), greater risk for ICU stay (N = 24, 14 % vs. N = 2, 1 %), and longer hospital stay (5.6 vs. 2.5 days). There were significantly more intraoperative liver (N = 13, 8 % vs. N = 1, 1 %) and spleen (N = 18, 10 % vs. N = 0) injuries, and more enterotomies (N = 9, 5 % vs. N = 0) in the revisional group. There were also significantly more postoperative complications (N = 94, 55 % vs. N = 48, 28 %), readmissions (N = 27, 16 % vs. N = 12, 7 %), and reoperations (N = 16, 9 % vs. N = 3, 2 %) within 30 days of surgery. Mean percentage weight loss at 1 year was significantly less for revisional patients (27 vs. 37 %). There was no significant difference in 30 day mortality between the two groups (N = 6 vs. 0).

CONCLUSION

Even in experienced hands, complex revisional bariatric surgery should be approached with significant caution, especially given that weight loss is less substantial.

Minimal clinically important differences of 3 patient-rated outcomes instruments

PURPOSE

Patient-rated instruments are increasingly used to measure orthopedic outcomes. However, the clinical relevance of modest score changes on such instruments is often unclear. This study was designed to define the minimal clinically important differences (MCIDs) of the Disabilities of the Arm, Shoulder, and Hand (DASH), QuickDASH (subset of DASH), and Patient-Rated Wrist Evaluation (PRWE) questionnaires for atraumatic conditions of the hand, wrist, and forearm.

METHODS

We prospectively analyzed 102 patients undergoing nonoperative treatment for isolated tendinitis, arthritis, or nerve compression syndromes from the forearm to the hand. By phone, patients completed the DASH, QuickDASH, and PRWE at enrollment and at 2 weeks (n = 78 used in the analysis) and 4 weeks (n = 24 used in the analysis) after initiating treatment. Patients reporting clinical improvement each contributed a single data point categorized as no change (n = 41), minimal improvement (n = 30), or marked improvement (n = 31) via a validated anchor-based approach. We calculated the MCID as the mean change score for each outcome measure in the minimal improvement group.

RESULTS

The MCID (95% confidence interval) for the DASH was 10 (5-15). The MCID for the QuickDASH was 14 (9-20). The MCID was 14 (8-20) for the PRWE. The MCID values were significantly different from changes in these outcome measures at times of either no change or marked improvement. The MCID values positively correlated with baseline outcome measure scores to a greater degree than final outcome measure scores.

CONCLUSIONS

Longitudinal changes on the DASH of 10 points, on the QuickDASH of 14 points, and on the PRWE of 14 points represent minimal clinically important changes. We recommend application of these MCID values for group-level analysis when conducting research and interpreting data examining groups of patients as opposed to assessing individual patients. These MCID values may provide a basis for sample size calculations for future investigation using these common patient-rated outcome measures.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

Pneumocystis carinii (jirovecii) pneumonia (PCP): the most common opportunistic infection observed in HIV/AIDS cases at the University Malaya Medical Centre, Kuala Lumpur, Malaysia

This retrospective study was conducted among 59 HIV/AIDS patients with opportunistic infections admitted to the University Malaya Medical Centre between 2000 and 2009. Fifty-five point nine percent of cases were Chinese, 25.4% were Malays, 11.9% were Indians and 6.8% were of unknown ethnic origin. The male:female ratio was 2.9:1 (44 males and 15 females). The highest prevalence (38.9%) occurred in the 30-39 year old age group. Men comprised 47.7% and women 53.3%; the majority of both were married. The majority of cases were Malaysians (89.8%) and the rest (10.2%) were immigrants. Most of the patients (18.6%) were non-laborers, followed by laborers (11.9%), the unemployed (5.1%) and housewives (3.4%). The most common risk factor was unprotected sexual activity (20.3%). The two most common HIV/AIDS related opportunistic infections were Pneumocystis carinii (jirovecii) pneumonia (PCP) (62.7%) and toxoplasmosis (28.8%). Seventy-two point nine percent of patients had a CD4 count <200 cells/microl and 5.1% had a CD4 count >500 cells/microl. Eleven point nine percent of cases died during study period. A low CD4 count had a greater association with opportunistic infections. Most of the patients presented with fever (44.1%), cough (42.4%) and shortness of breath (28.8%). Detection of the etiologic pathogens aids clinicians in choosing appropriate management strategies.

Application of tissue-engineered cartilage with BMP-7 gene to repair knee joint cartilage injury in rabbits

Injured articular cartilage has a poor capacity for spontaneous healing. So far, satisfactory solution to this subsistent problem has not been found, but transgenic therapy may be a promising way. This study aims to evaluate the effectiveness of a tissue-engineered cartilage that was transfected with morphogenetic protein 7 (BMP 7) in repairing the cartilaginous defects of rabbit knee joints. Chondrocytes were transfected with BMP-7 gene (5 x 10(6) cells/ml), inoculated into the collagen-fibrin gel scaffolds, and cultured for 14 days. Then, the scaffolds were implanted onto the created defects (5.0 mm in diameter) in rabbits' knee joints. After 12 weeks, the rabbits were sacrificed and histological sections were evaluated using modified O'Driscoll cartilage scores; In situ hybridization and immunohistochemistry were performed to detect the expression of BMP-7 mRNA and BMP-7 at the implanted site while the content of DNA and GAG was determined as well. A better quality of repairs was observed at the 12th week after implantation when compared to the control group using histological analyses. The content of DNA and specific secretion of GAG in the treatment group is statistically significant different compared with the control group. Gene therapy may be a promising treatment method, but the novel therapy approach needs further studies with respect to a longer follow-up period.

Molecular recognition of acute myeloid leukemia using aptamers

Cell surface proteins can play important roles in cancer pathogenesis. Comprehensive understanding of the surface protein expression patterns of tumor cells and, consequently, the pathogenesis of tumor cells, depends on molecular probes against these proteins. To be effectively used for tumor diagnosis, classification and therapy, such probes would be capable of specific binding to targeted tumor cells. Molecular aptamers, designer DNA/RNA probes, can address this challenge by recognizing proteins, peptides and other small molecules with high affinity and specificity. Through a process known as cell-SELEX, we used live acute myeloid leukemia (AML) cells to select a group of DNA aptamers that can recognize acute myeloid leukemia cells with dissociation constants (Kds) in the nanomolar range. Interestingly, one aptamer (KH1C12), compared with two control cell lines (K562 and NB4), showed significant selectivity to the target AML cell line (HL60) and could recognize the target cells within a complex mixture of normal bone marrow aspirates. The other two aptamers KK1B10 and KK1D04 recognize targets associated with monocytic differentiation. Our studies demonstrate that the selected aptamers can be used as a molecular tool for further understanding surface protein expression patterns on tumor cells and thus providing a foundation for effective molecular analysis of leukemia and its subcategories.

Attitudes towards cancer survivors: a small survey

INTRODUCTION

The National Cancer Survivors Day Foundation defines a cancer "survivor" as anyone living with a history of cancer--from the moment of diagnosis through the remainder of life. Little is known about the size and make-up of this population or about the medical care experience of and social implications for patients who have had a diagnosis of cancer in Singapore. An opportunistic survey was undertaken to understand how members of the public believe about this population.

METHODS

A sample of the general public was undertaken during the "CancerVive" event in 2004. Questionnaires regarding employment as well as attitudes towards cancer and cancer survivorship were distributed.

RESULTS

Members of the public held certain misconceptions about cancer survivors. They also have certain negative attitudes toward cancer survivors. Beliefs and attitudes about cancer are similar for cancer survivors and the general public. Although members of the public had positive attitudes towards working with cancer survivors, the majority felt that cancer survivors should not be given equal opportunities at work, by not employing cancer survivors if they were in the position to hire.

CONCLUSION

Further research with larger and more representative samples needs to be undertaken to extend the understanding into cancer survivorship issues.

Selenium supplementation of children in a selenium-deficient area in China: blood selenium levels and glutathione peroxidase activities

Keshan disease is a cardiomyopathy restricted to the endemic areas of China and seen in residents having an extremely low selenium (Se) status. Prophylactic administration of sodium selenite has been shown to decrease significantly the incidence of acute and subacute cases. The aim offthe study was to assess the relative bioavailability of selenite versus organic Se-yeast in a Se-deficient area in China with a randomized double-blind double-dummy design. Healthy children (n=30) between 14 and 16 yr of age were randomized into three equal groups receiving either 200 microg/d selenite Se or 200 microg/d Se-yeast or placebo for 12 wk. Blood was drawn at baseline, 4, 8, and 12 wk and 4 wk postsupplementation. The plasma Se concentration (mean +/- SD) was 0.16+/-0.03 micromol/L at baseline. Selenite and Se-yeast supplementation increased plasma Se to plateau values, 1.0+/-0.2 and 1.3+/-0.2 micromol/L, respectively. In red cells, Se-yeast increased the selenium level sixfold and selenite threefold compared to placebo. The relative bioavailability of Se-yeast versus selenite measured as glutathione peroxidase (GSHPx) activity was similar in plasma, red blood cells, and platelets. GSHPx activity reached maximal levels in plasma and platelets of 300% and 200%, respectively, after 8 wk compared to the placebo group, but continued to increase in red cells for 16 wk. Our study showed that although both forms of Se were equally effective in raising GSHPx activity, Se-yeast provided a longer lasting body pool of Se. Se-yeast may be a better alternative to selenite in the prophylaxis of Keshan disease with respect to building up of body stores.

Enzyme-linked immunosorbent assay (ELISA) for IgA and IgG antibodies to Epstein-Barr-virus ribonucleotide reductase in patients with nasopharyngeal carcinoma

661 bp coding for the carboxyl end of the large sub-unit of EBV ribonucleotide reductase was cloned into the pMal plasmid vector. Purified recombinant protein was tested in IgG and IgA ELISAs. For the IgG assay, 81 out of 100 NPC patients tested positive, whereas for the IgA assay, 60 tested positive. Among 100 normal individuals, I tested positive for the IgG assay and 9 tested positive for the IgA assay. The IgG assay picked up 6 out of 19 NPC sera which were IFA-VCA- and IFA-EA-negative for IgA antibodies. Hence the recombinant ribonucleotide reductase could have good potential as a diagnostic test for NPC or could serve as a complementary test to IFA.

Molecular cloning and expression of Epstein-Barr virus antigens in the lambda gt11 expression vector: antibodies towards proteins from the BORF2 and BKRF4 reading frames in nasopharyngeal carcinoma patients

An easy way to clone and screen for Epstein-Barr virus antigens significant in the diagnosis of nasopharyngeal carcinoma (NPC) has been developed. Two proteins cloned and expressed as fusion proteins in lambda gt11 have been identified to be expressed from 661 bp of the BORF2 and from 500 bp of the BNKRF4 reading frames. Western blotting studies on these proteins using serum from 16 NPC and 16 normal healthy individuals showed that 15 NPC patients have either IgG or IgA antibodies towards either protein whereas only 2 normal individuals were positive. Hence, IgG and IgA antibodies towards these antigens are of diagnostic value for NPC.