Clinical emergence of entecavir-resistant hepatitis B virus requires additional substitutions in virus already resistant to Lamivudine

Entecavir (ETV) exhibits potent antiviral activity in patients chronically infected with wild-type or lamivudine (3TC)-resistant (3TC(r)) hepatitis B virus (HBV). Among the patients treated in phase II ETV clinical trials, two patients for whom previous therapies had failed exhibited virologic breakthrough while on ETV. Isolates from these patients (arbitrarily designated patients A and B) were analyzed genotypically for emergent substitutions in HBV reverse transcriptase (RT) and phenotypically for reduced susceptibility in cultures and in HBV polymerase assays. After 54 weeks of 3TC therapy, patient A (AI463901-A) received 0.5 mg of ETV for 52 weeks followed by a combination of ETV and 100 mg of 3TC for 89 weeks. Viral rebound occurred at 133 weeks after ETV was started. The 3TC(r) RT substitutions rtV173L, rtL180M, and rtM204V were present at study entry, and the additional substitutions rtI169T and rtM250V emerged during ETV-3TC combination treatment. Reduced ETV susceptibility in vitro required the rtM250V substitution in addition to the 3TC(r) substitutions. For liver transplant patient B (AI463015-B), previous famciclovir, ganciclovir, foscarnet, and 3TC therapies had failed, and RT changes rtS78S/T, rtV173L, rtL180M, rtT184S, and rtM204V were present at study entry. Viral rebound occurred after 76 weeks of therapy with ETV at 1.0 mg, with the emergence of rtT184G, rtI169T, and rtS202I substitutions within the preexisting 3TC(r) background. Reduced susceptibility in vitro was highest when both the rtT184G and the rtS202I changes were combined with the 3TC(r) substitutions. In summary, infrequent ETV resistance can emerge during prolonged therapy, with selection of additional RT substitutions within a 3TC(r) HBV background, leading to reduced ETV susceptibility and treatment failure.

Complications of growing-rod treatment for early-onset scoliosis: analysis of one hundred and forty patients

BACKGROUND

Previous reports have indicated high complication rates associated with non-fusion surgery in patients with early-onset scoliosis. This study was performed to evaluate the clinical and radiographic complications associated with growing-rod treatment.

METHODS

Data from the multicenter Growing Spine Study Group database were evaluated. Inclusion criteria were growing-rod treatment for early-onset scoliosis and a minimum of two years of follow-up. Patients were divided into treatment groups according to rod type (single or dual) and rod location (subcutaneous or submuscular). Complications were categorized as wound, implant, alignment, and general (surgical or medical). Surgical procedures were classified as planned and unplanned.

RESULTS

Between 1987 and 2005, 140 patients met the inclusion criteria and underwent a total of 897 growing-rod procedures. The mean age at the initial surgery was six years, and the mean duration of follow-up was five years. Eighty-one (58%) of the 140 patients had a minimum of one complication. Nineteen (27%) of the seventy-one patients with a single rod had unplanned procedures because of implant complications, compared with seven (10%) of the sixty-nine patients with dual rods (p ≤ 0.05). Thirteen (26%) of the fifty-one patients with subcutaneous rod placement had wound complications compared with nine of the eighty-eight patients (10%) with submuscular rod placement (p ≤ 0.05). The patients with subcutaneous dual rods had more wound complications, more prominent implants, and more unplanned surgical procedures than did those with submuscular dual rods (p ≤ 0.05). The risk of complications occurring during the treatment period decreased by 13% for each year of increased patient age at the initiation of treatment. The complication risk increased by 24% for each additional surgical procedure performed.

CONCLUSIONS

Regardless of treatment modality, the management of early-onset scoliosis is prolonged; therefore, complications are frequent and should be expected. Complications can be reduced by delaying initial implantation of the growing rods if possible, using dual rods, and limiting the number of lengthening procedures. Submuscular placement reduces wound and implant-prominence complications and reduces the number of unplanned operations.

Standardization of criteria for adolescent idiopathic scoliosis brace studies: SRS Committee on Bracing and Nonoperative Management

STUDY DESIGN

Literature review.

OBJECTIVE

To establish consistent parameters for future adolescent idiopathic scoliosis bracing studies so that valid and reliable comparisons can be made.

SUMMARY OF BACKGROUND DATA

Current bracing literature lacks consistency for both inclusion criteria and the definitions of brace effectiveness.

METHODS

A total of 32 brace treatment studies and the current bracing in adolescent idiopathic scoliosis proposal were analyzed to: (1) determine inclusion criteria that will best identify those patients most at risk for progression, (2) determine the most appropriate definitions for bracing effectiveness, and (3) identify additional variables that would provide valuable information.

RESULTS

Early brace studies lacked clarity in their inclusion criteria. In more recent studies, inclusion criteria have narrowed considerably to include primarily those patients most at risk for curve progression who may benefit from the use of a brace. Brace effectiveness was usually defined by various degrees of curve progression at maturity. Less frequently, it was defined by the resultant curve magnitude at maturity, whether or not surgical intervention was needed, or if there was change to another brace.

CONCLUSIONS

Optimal inclusion criteria for future adolescent idiopathic scoliosis brace studies consist of: age is 10 years or older when brace is prescribed, Risser 0-2, primary curve angles 25 degrees -40 degrees , no prior treatment, and, if female, either premenarchal or less than 1 year postmenarchal. Assessment of brace effectiveness should include: (1) the percentage of patients who have < or =5 degrees curve progression and the percentage of patients who have > or =6 degrees progression at maturity, (2) the percentage of patients with curves exceeding 45 degrees at maturity and the percentage who have had surgery recommended/undertaken, and (3) 2-year follow-up beyond maturity to determine the percentage of patients who subsequently undergo surgery. All patients, regardless of subjective reports on compliance, should be included in the results (intent to treat). Every study should provide results stratified by curve type and size grouping.

Birthweight and adult health outcomes in a biethnic population in the USA

Recent data indicate that low-birthweight adults are at a higher risk than their high-birthweight peers of developing ischemic heart disease or a cluster of conditions known as the IRS, which includes dyslipidaemias, hypertension, unfavorable body fat distribution and NIDDM. Thus far these observations have been limited to Caucasians from the United Kingdom. we extended these observations to a broader segment of the general population by studying the association of birthweight and adult health outcomes in a biethnic population of the United States. We divided a group of 564 young adult Mexican-American and non-Hispanic white men and women participants of the San Antonio Heart Study into tertiles of birthweight and compared metabolic, anthropometric, haemodynamic, and demographic characteristics across these tertile categories. Additionally, we studied birthweight as a predictor of the clustering of diseases associated with the IRS, defined as any two or more of the following conditions: hypertension, NIDDM or impaired glucose tolerance, dyslipidaemia. Normotensive, non-diabetic individuals whose birthweight was in the lowest tertile had significantly higher levels of fasting serum insulin and a more truncal fat deposition pattern than individuals whose birthweight was in the highest tertile, independently of sex, ethnicity, and current socioeconomic status. Also, the odds of expressing the IRS increased 1.72 times (95% confidence interval: 1.16-2.55) for each tertile decrease in birthweight. These findings were independent of sex, ethnicity, and current levels of socioeconomic status or obesity. In conclusion, low birthweight could be a major independent risk factor for the development of adult chronic conditions commonly associated with insulin resistance in the general population.

The treatment of pulp and paper mill effluent: a review

The manufacture of paper generates significant quantities of wastewater; as high as 60 m3/tonne of paper produced. The raw wastewaters from paper and board mills can be potentially very polluting. Indeed, a recent survey within the UK industry has found that their chemical oxygen demands can be as high as 11000 mg/l. This paper reviews the processes involved in paper making and examines the effects which they could have on the environment. It also evaluates the treatment processes which are used to minimise these effects. In line with the majority of UK practice, it focuses mainly on aerobic biological treatment and, in particular, on the activated sludge process. This means that there is an in-depth discussion about the problems associated with filamentous bacteria and sludge "bulking". The paper also discusses the way in which anaerobic digestion can be applied to the treatment of liquid wastes from the manufacture of paper.

Comparison of single and dual growing rod techniques followed through definitive surgery: a preliminary study

STUDY DESIGN

Retrospective analysis of patients treated with single and dual growing rods who had completed their course of treatment, had definitive fusion, and had a minimum of 2 years follow-up.

OBJECTIVES

To determine which technique was the most effective in the management of severe spinal deformity in young children: control of the spinal deformity, spinal growth, and the incidence of complications.

SUMMARY OF BACKGROUND DATA

Growing rod techniques provide proximal and distal segmental "claw" foundations, but their overall results through definitive fusion have not been clearly determined.

METHODS

A total of 28 consecutive patients who had growing rod procedures followed through definitive spinal fusions were analyzed. There were three patient groups: Group 1 (N = 5), single submuscular rod and short apical fusion; Group 2 (N = 16), single growing rod alone; and Group 3 (N = 7), dual growing rods.

RESULTS

The interval between initial rod insertion and definitive spinal fusion was similar in all three groups. The best overall results occurred in Group 3, whereas the patients in Group 1 had the worse results. Both Groups 2 and 3 provided good initial correction of the spinal deformity and allowed spinal growth. Group 2 had better frontal and sagittal plane balance and the lowest complication rate.

CONCLUSION

The use of growing rods is effective in controlling severe spinal deformities and allowing spinal growth. Dual rods are stronger than single rods and, therefore, provide better initial correction and maintenance of correction. The use of an apical fusion does not appear to be effective over the course of treatment.

Development and initial validation of the Classification of Early-Onset Scoliosis (C-EOS)

BACKGROUND

Early-onset scoliosis is a heterogeneous condition, with highly variable manifestations and natural history. No standardized classification system exists to describe and group patients, to guide optimal care, or to prognosticate outcomes within this population. A classification system for early-onset scoliosis is thus a necessary prerequisite to the timely evolution of care of these patients.

METHODS

Fifteen experienced surgeons participated in a nominal group technique designed to achieve a consensus-based classification system for early-onset scoliosis. A comprehensive list of factors important in managing early-onset scoliosis was generated using a standardized literature review, semi-structured interviews, and open forum discussion. Three group meetings and two rounds of surveying guided the selection of classification components, subgroupings, and cut-points. Initial validation of the system was conducted using an interobserver reliability assessment based on the classification of a series of thirty cases.

RESULTS

Nominal group technique was used to identify three core variables (major curve angle, etiology, and kyphosis) with high group content validity scores. Age and curve progression ranked slightly lower. Participants evaluated the cases of thirty patients with early-onset scoliosis for reliability testing. The mean kappa value for etiology (0.64) was substantial, while the mean kappa values for major curve angle (0.95) and kyphosis (0.93) indicated almost perfect agreement. The final classification consisted of a continuous age prefix, etiology (congenital or structural, neuromuscular, syndromic, and idiopathic), major curve angle (1, 2, 3, or 4), and kyphosis (-, N, or +) variables, and an optional progression modifier (P0, P1, or P2).

CONCLUSIONS

Utilizing formal consensus-building methods in a large group of surgeons experienced in treating early-onset scoliosis, a novel classification system for early-onset scoliosis was developed with all core components demonstrating substantial to excellent interobserver reliability. This classification system will serve as a foundation to guide ongoing research efforts and standardize communication in the clinical setting.

Growing rod techniques in early-onset scoliosis

BACKGROUND

The surgical treatment of severe early-onset scoliosis (EOS) is controversial. Obtaining and maintaining deformity correction, achieving adequate spinal growth, allowing lung development, and the high complication rate make surgical treatment very challenging. Growing rods are the most common method of management.

METHODS

Currently, there are 3 systems being used for the surgical treatment of EOS: single growing rod, dual growing rods, and the vertical expandable titanium prosthetic rib implant. Each system has its advantages and disadvantages. These are presented and discussed in this review.

RESULTS

The current clinical and radiographic results indicate that all 3 techniques can be effective in the surgical management of EOS. Vertical expandable prosthetic titanium rib (VEPTR), which is not considered a true growing rod system, is particularly effective in congenital scoliosis with fused ribs.

CONCLUSIONS

The current expandable spinal implant systems appear effective in controlling progressive EOS, allowing for spinal growth and improving lung development. All have a moderate complication rate, especially rod breakage and hook displacement.

Defects in the low density lipoprotein receptor gene affect lipoprotein (a) levels: multiplicative interaction of two gene loci associated with premature atherosclerosis

The lipoprotein (a) [Lp(a)] contains two nonidentical protein species, apolipoprotein (apo) B-100 and a specific high molecular weight glycoprotein, apo(a). Lp(a) represents a continuous quantitative genetic trait, the genetics of which are only poorly understood. Genetic variation at the apo(a) locus affects plasma Lp(a) levels and explains at least 40% of the variability of this trait. Lp(a) levels were found to be elevated 3-fold in the plasma from patients with the heterozygous form of familial hypercholesterolemia who have one mutant low density lipoprotein receptor gene. This elevation was not due to a higher frequency of those apo(a) types that are associated with high Lp(a) levels in familial hypercholesterolemia patients. Rather Lp(a) levels were elevated for each of the apo(a) phenotypes examined. The effects of the apo(a) and low density lipoprotein receptor genes on Lp(a) levels are not additive but multiplicative. This is a situation not commonly considered in quantitative human genetics. We conclude that Lp(a) levels in plasma may be determined by variation at more than one gene locus.

Dynamic contrast-enhanced imaging techniques: CT and MRI

Over the last few decades there has been considerable research into quantifying the cerebral microvasculature with imaging, for use in studies of the human brain and various pathologies including cerebral tumours. This review highlights key issues in dynamic contrast-enhanced CT, dynamic contrast-enhanced MRI and arterial spin labelling, the various applications of which are considered elsewhere in this special issue of the British Journal of Radiology.

Traditional Growing Rods Versus Magnetically Controlled Growing Rods for the Surgical Treatment of Early-Onset Scoliosis: A Case-Matched 2-Year Study

INTRODUCTION

Traditional growing rod (TGR) surgery is a treatment technique commonly used for progressive early-onset scoliosis. Studies have shown that repeated TGR lengthenings can significantly increase the risk of complications. Magnetically controlled growing rods (MCGR) are currently available outside of the United States and early results have been promising. The purpose of this study was to compare the effectiveness of MCGR versus TGR for the treatment of early-onset scoliosis.

METHODS

Magnetically controlled growing rod patients were selected based on the following criteria: aged less than 10 years, major curve greater than 30°, thoracic height less than 22 cm, no previous spine surgery, and minimum 2-year follow-up. A total of 17 MCGR patients met the inclusion criteria, 12 of whom had complete data available for analysis. Each MCGR patient was matched with a TGR patient by etiology, gender, single versus dual rods, preoperative age, and preoperative major curve.

RESULTS

Magnetically controlled growing rod patients had a mean age of 6.8 years and mean follow-up of 2.5 years. Mean follow-up was greater for TGR patients by 1.6 years. Major curve correction was similar between MCGR and TGR patients throughout treatment. The MCGR patients experienced an average of 8.1 mm/year increase in T1-S1 during the lengthening period, compared with 9.7 mm/year for TGR patients (p = .73). There was a mean increase in T1-T12 of 1.5 mm/year for MCGR patients and 2.3 mm/year for TGR patients (p = .83). The TGR patients had 73 open surgeries, 56 of which were lengthenings. The MCGR patients had 16 open surgeries and 137 noninvasive lengthenings. Three TGR patients underwent 5 unplanned revision surgeries whereas 3 MCGR patients underwent 4 unplanned revisions.

CONCLUSIONS

Major curve correction was similar between MCGR and TGR patients throughout treatment. Annual T1-S1 and T1-12 growth was also similar between groups. The MCGR patients had 57 fewer surgical procedures than TGR patients. Incidence of unplanned surgical revisions as a result of complications was similar between groups.

Long-term biomedical and psychosocial outcomes following DAFNE (Dose Adjustment For Normal Eating) structured education to promote intensive insulin therapy in adults with sub-optimally controlled Type 1 diabetes

AIMS

To explore long-term outcomes of participation in a Dose Adjustment For Normal Eating (DAFNE) training course, which provided one-off exposure to structured education in intensive insulin therapy to people with established Type 1 diabetes.

METHODS

A cohort design follow-up of original trial participants at a mean of 44 months (range: 37-51 months) in hospital diabetes clinics in three English health districts. 104 (74%) original participants provided biomedical data; 88 (63%) completed questionnaires including the ADDQoL, measuring impact of diabetes on quality of life (QoL).

RESULTS

At 44 months, mean improvement in HbA(1c) from baseline was 0.36% (9.32+/-1.1% to 8.96+/-1.2%, p<0.01) remaining significant but deteriorated from 12 months (p<0.05). Improvements in QoL seen at 12 months were sustained at 44 (e.g. impact of diabetes on dietary freedom: -1.78+/-2.33 at 44 months versus -4.27+/-2.94, baseline, p<0.0001; versus 1.80+/-2.32 at 12 months, ns). Similar results were obtained using last observation carried forward for patients not supplying follow-up data.

CONCLUSIONS

The impact of a single DAFNE course on glycaemic control remains apparent in the long term, although further interventions will be required to achieve recommended HbA(1c). In contrast, improvements in QoL and other patient-reported outcomes are well maintained over approximately 4 years.

Delineation of the Cdc42/Rac-binding domain of p21-activated kinase

p21-activated kinases (PAKs) serve as effector proteins for the GTP-binding proteins Cdc42 and Rac. They are serine/threonine kinases containing the Cdc42/Rac interactive binding (CRIB) motif. The main aim of this study was to define the minimal domain of alphaPAK required for Cdc42/Rac binding. Eight stable PAK fragments of varying lengths, each containing the CRIB motif (residues 75-88), were expressed in Escherichia coli, and their ability to interact with Cdc42 and Rac was assessed using scintillation proximity assays, isothermal titration calorimetry, and fluorescence techniques. The shortest fragments examined (residues 70-94 and 75-94) bound only weakly to either Cdc42 or Rac. A longer fragment starting at residue 75 and ending at residue 105 showed binding to Q61L Rac.GTP with Kd = 1.9 microM. Highest affinity binding (Kd approximately 0.05 microM) was seen with longer fragments ending at residue 118 or 132. A small increase in affinity was seen with those fragments starting at residue 70 rather than residue 75. PAK fragments bound with approximately 3-10-fold higher affinity to Cdc42 than to Rac and bound Q61L variants with 5-10-fold higher affinity than wild type. The dissociation rates of Q61L Rac.mant-GTP and of Q61L Cdc42. mant-GTP from PAK fragment residues 70-132 were measured to be 0.66 and 0.25 min-1, respectively, which are 100-fold lower than dissociation rates for Ras:Ras-effector domains, although their affinities are similar. Calorimetric measurements revealed that binding was associated with a relatively slow heat change. It is suggested that these PAK fragments (in the absence of Cdc42 or Rac) might exist predominantly in an inactive conformation that slowly interconverts with an active conformation and/or a slow conformational change may occur upon binding to Cdc42/Rac. In conclusion, the PAK CRIB motif itself is insufficient for high-affinity binding to Cdc42/Rac, but a 30 amino acid region of PAK (residues 75-105), containing this motif, is sufficient.

DCE-MRI biomarkers of tumour heterogeneity predict CRC liver metastasis shrinkage following bevacizumab and FOLFOX-6

BACKGROUND

There is limited evidence that imaging biomarkers can predict subsequent response to therapy. Such prognostic and/or predictive biomarkers would facilitate development of personalised medicine. We hypothesised that pre-treatment measurement of the heterogeneity of tumour vascular enhancement could predict clinical outcome following combination anti-angiogenic and cytotoxic chemotherapy in colorectal cancer (CRC) liver metastases.

METHODS

Ten patients with 26 CRC liver metastases had two dynamic contrast-enhanced MRI (DCE-MRI) examinations before starting first-line bevacizumab and FOLFOX-6. Pre-treatment biomarkers of tumour microvasculature were computed and a regression analysis was performed against the post-treatment change in tumour volume after five cycles of therapy. The ability of the resulting linear model to predict tumour shrinkage was evaluated using leave-one-out validation. Robustness to inter-visit variation was investigated using data from a second baseline scan.

RESULTS

In all, 86% of the variance in post-treatment tumour shrinkage was explained by the median extravascular extracellular volume (v(e)), tumour enhancing fraction (E(F)), and microvascular uniformity (assessed with the fractal measure box dimension, d(0)) (R(2)=0.86, P<0.00005). Other variables, including baseline volume were not statistically significant. Median prediction error was 12%. Equivalent results were obtained from the second scan.

CONCLUSION

Traditional image analyses may over-simplify tumour biology. Measuring microvascular heterogeneity may yield important prognostic and/or predictive biomarkers.

The effect of amicar on perioperative blood loss in idiopathic scoliosis: the results of a prospective, randomized double-blind study

STUDY DESIGN

A prospective, randomized, double-blind Institutional Review Board-approved study evaluating the efficacy of Amicar (epsilon aminocaproic acid), an antifibrinolytic agent, in decreasing perioperative blood loss in idiopathic scoliosis.

OBJECTIVES

To compare the perioperative (intraoperative and postoperative) blood loss and the need for autologous and homologous blood replacement in two groups of essentially identical patients undergoing a posterior spinal fusion for idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Reducing perioperative blood loss and the need for transfusion in patients undergoing spinal surgery is important to orthopedic surgeons. Recently, there has been interest in pharmacologic agents, particularly Amicar and Aprotinin, to assist in decreasing perioperative blood loss. In 2001, in a preliminary study, we demonstrated that Amicar appeared to be effective in reducing perioperative blood loss in patients with idiopathic scoliosis undergoing a posterior spinal fusion and segmental spinal instrumentation. This was a study of 28 consecutive patients receiving Amicar compared to a historical control group of the 31 previous consecutive patients with the same study criteria. The current study was performed to confirm our preliminary findings.

METHODS

We analyzed the perioperative blood loss of 36 patients with idiopathic scoliosis who were blindly randomized by the operating room pharmacy into an Amicar and control group. The criteria to be included in the study was the same as the preliminary study: diagnosis of idiopathic scoliosis, age at surgery 11 to 18 years, posterior spinal fusion and segmental spinal instrumentation only, autogenous iliac crest bone graft or homologous cancellous bone graft, and a signed agreement to participate in the study. The patients in both groups had the same anesthetic technique, intraoperative procedure, instrumentation, postoperative management, and standardized indications for transfusions.

RESULTS

Before surgery, the patients in both groups were essentially identical. The distribution of patients and their results was not known until the completion of the study. Patients in the Amicar group demonstrated a statistically significant decrease in perioperative blood loss and the need for autologous blood transfusion. Interestingly, this decrease was predominantly in the postoperative suction drainage. This may be due to elevated fibrinogen levels induced by Amicar. The patients taking Amicar had no intraoperative or postoperative thromboembolic complications.

CONCLUSIONS

The results of this study confirmed that the use of intraoperative Amicar is a safe, effective, and inexpensive method to significantly reduce perioperative blood loss in patients with idiopathic scoliosis undergoing posterior spinal fusion and segmental spinal instrumentation. The results have allowed us to reduce our recommendation for perioperative autologous blood donation, thereby further decreasing costs.

Growing-rod graduates: lessons learned from ninety-nine patients who completed lengthening

BACKGROUND

Growing-rod spinal instrumentation systems are a valuable tool for managing severe early-onset scoliosis. There is little information about the end point of treatment.

METHODS

A multicenter early-onset-scoliosis database was searched to identify patients who had undergone treatment with growing rods and either had had a final operative procedure or were still being treated with the growing rods after reaching skeletal maturity (defined as fourteen years of age or older). Clinical, radiographic, and operative data were analyzed.

RESULTS

Ninety-nine patients met the inclusion criteria, and ninety-two (93%) of them had had a final operative procedure. The remaining seven patients (7%) were older than fourteen years but had not undergone a final procedure. Of the ninety-two patients who had a final procedure, seventy-nine (86%) had an instrumented fusion, nine (10%) had growing-rod exchanges and fusion in situ, three (3%) had the growing rods left in place and fusion in situ, and one (1%) had only growing-rod removal. The mean age (and standard deviation) at the final fusion was 12.4 ± 1.9 years. In forty-four (55%) of eighty patients for whom the information was available, the number of vertebral levels fused was the same as the number of vertebral levels spanned by the growing rods. The percent correction of the curve after final fusion was none or minimal (≤ 20 %) in eleven (18%) of the sixty-two patients for whom sufficient-quality radiographs were available, moderate (21% to 50%) in thirty (48%), and substantial (≥ 51 %) in nine (15%); the curve had worsened in twelve patients (19%). The mean duration of growing-rod treatment was 5.0 ± 2.6 years. Of fifty-eight operative reports made at final fusion that contained comments on spinal flexibility, eleven (19%) described the spine as being mobile, eleven (19%) described decreased flexibility, and thirty-six (62%) described the spine as being completely stiff. At final fusion, twenty-two patients (24%) had osteotomies and seven patients (8%) had a thoracoplasty.

CONCLUSIONS

Most patients underwent growing-rod removal and final instrumented fusion. The final fusion often included the same levels spanned by the growing rods and usually achieved <50% additional correction of the deformity remaining at the end of the growing-rod management.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Effect of epsilon-aminocaproic acid on perioperative blood loss in patients with idiopathic scoliosis undergoing posterior spinal fusion: a preliminary prospective study

STUDY DESIGN

A prospective study evaluating the efficacy of epsilon-aminocaproic acid (EACA) in decreasing perioperative blood loss in idiopathic scoliosis.

OBJECTIVES

To compare the perioperative blood loss and need for blood replacement in two groups of patients undergoing surgery for idiopathic scoliosis. One group received intraoperative EACA; the other did not and served as controls.

SUMMARY OF BACKGROUND DATA

Excessive blood loss increases the operative time, risk for blood product disease transmission, postoperative complications, and costs associated with posterior spinal fusion and instrumentation. EACA is an antifibrinolytic agent that has been shown to be effective in reducing perioperative blood loss during pediatric cardiothoracic surgical procedures. We hypothesized that it would also be effective in lowering blood loss during posterior spinal fusion for idiopathic scoliosis.

METHODS

We compared the perioperative blood loss of 28 consecutive pediatric patients with idiopathic scoliosis who underwent posterior spinal fusion and received intraoperative EACA with 31 consecutive patients who did not receive this medication and served as a control group.

RESULTS

The patients in both groups were similar. Patients in the EACA group demonstrated statistically significant decreases in total estimated perioperative blood loss and the need for autologous blood transfusion. The patients in the EACA group had no intraoperative or postoperative complications related to the use of this medication.

CONCLUSIONS

Based on these preliminary findings, we believe that EACA is helpful in decreasing blood loss in patients undergoing posterior spinal fusion and instrumentation, and may decrease the number of autologous units needed to maintain safe perioperative hemoglobin levels, thereby improving safety and lowering cost associated with scoliosis surgery.

Cerebrospinal fluid flow abnormalities in patients with neoplastic meningitis. An evaluation using 111indium-DTPA ventriculography

Cerebrospinal fluid flow dynamics were evaluated by 111Indium-diethylenetriamine pentaacetic acid (111In-DTPA) ventriculography in 27 patients with neoplastic meningitis. Nineteen patients (70 percent) had evidence of cerebrospinal fluid flow disturbances. These occurred as ventricular outlet obstructions, abnormalities of flow in the spinal canal, or flow distrubances over the cortical convexities. Tumor histology, physical examination, cerebrospinal fluid analysis, myelograms, and computerized axial tomographic scans were not sufficient to predict cerebrospinal fluid flow patterns. These data indicate that cerebrospinal fluid flow abnormalities are common in patients with neoplastic meningitis and that 111In-DTPA cerebrospinal fluid flow imaging is useful in characterizing these abnormalities. This technique provides insight into the distribution of intraventricularly administered chemotherapy and may provide explanations for treatment failure and drug-induced neurotoxicity in patients with neoplastic meningitis.

Androgenic control of the harderian gland in the male golden hamster

In the golden hamster, there are marked sex differences in the Harderian gland. Male glands (which are heavier than female glands) possess two cell forms (Type I and Type II cells); female glands only exhibit the former. Female (but not male) glands contain large amounts of porphyrin, which are readily visible as solid depositions within the lumina. The weight, histology and porphyrin content of the Harderian gland was examined in intact adult male hamsters and in male hamsters castrated for 1,2 or 8 months. Castration resulted in a significant reduction in the weight of the gland, the disappearance of Type II cells, and the presence in the gland of solid porphyrin accretions. The levels of copro- and (especially) protoporphyrin were greatly increased. These changes were more marked with time after castration. When the ability of diverse androgens (testosterone, 5alpha-dihydrotestosterone, androst-4-ene-3,17-dione (androstenedione), dehydroepiandrosterone and androsterone) to prevent these changes was tested, testosterone and androstenedione maintained glandular weight. All the androgens maintained normal frequencies of Type II cells and all except dehydroepiandrosterone prevented deposition of porphyrin. The potencies of the various androgens in maintaining normal Harderian gland morphology and activity are compared with their effects on other somatic variables and sexual behaviour.

Deep Surgical Site Infection Following 2344 Growing-Rod Procedures for Early-Onset Scoliosis: Risk Factors and Clinical Consequences

BACKGROUND

Deep surgical site infection may change the course of growing-rod treatment of early-onset scoliosis. Our goal was to assess the effect of this complication on subsequent treatment.

METHODS

A multicenter international database was retrospectively reviewed; 379 patients treated with growing-rod surgery and followed for a minimum of two years were identified. Deep surgical site infection was defined as any infection requiring surgical intervention.

RESULTS

Forty-two patients (11.1%; twenty-five males and seventeen females) developed at least one deep surgical site infection. The mean age at the initial growing-rod surgery was 6.3 years (range, 0.6 to 13.2 years) and the mean duration of follow-up was 5.3 years (range, 2.2 to 14.3 years). The mean interval between the initial surgery and the first deep surgical site infection was 2.8 years (range, 0.02 to 7.9 years). Ten (2.6%) of the 379 patients developed deep surgical site infection before the first lengthening. Twenty-nine patients (7.7%) developed the infection during the course of the lengthening procedures, and three patients (0.8%) developed it after final fusion surgery. Thirty (13.6%) of 221 patients with stainless-steel implants had at least one deep surgical site infection compared with twelve (8%) of 150 patients with titanium implants (p < 0.05). (The remaining patients were treated with chromium-cobalt implants.) Twenty-two (52.4%) of the forty-two patients with deep surgical site infection underwent implant removal, which was complete in thirteen and partial in nine. Growing-rod treatment was terminated in two patients with partial removal and six patients with complete removal. An increased risk of deep surgical site infection was associated with stainless-steel implants (odds ratio [OR] = 5.7), non-ambulatory status (OR = 2.9), and the number of revisions before the development of deep surgical site infection (OR = 3.3). Neuromuscular etiology and non-ambulatory status increased the possibility of implant removal to treat infection (p < 0.05).

CONCLUSIONS

The prevalence of deep surgical site infection associated with growing-rod surgery is higher than that associated with standard pediatric spinal fusion (historical data). Non-ambulatory status, more revisions, and stainless-steel implants increased the risk of deep surgical site infection. After eight surgical procedures, the risk of deep surgical site infection increased to approximately 50%. When patients have implant removal, efforts should be made to retain one longitudinal implant to continue treatment.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

A comparison of the thoracolumbosacral orthoses and providence orthosis in the treatment of adolescent idiopathic scoliosis: results using the new SRS inclusion and assessment criteria for bracing studies

This is a retrospective cohort study comparing the effectiveness of the thoracolumbosacral orthosis (TLSO) and the Providence orthosis in the treatment of adolescent idiopathic scoliosis (AIS) using the new Scoliosis Research Society (SRS) Committee on Bracing and Nonoperative Management inclusion and assessment criteria for bracing studies. These new criteria will make future studies comparable and more valid and accurate.

METHODS

We have used a custom TLSO (duration, 22 hours/day) and the Providence orthosis (duration, 8-10 hours/night) to control progressive AIS curves. Only 83 of 160 patients met the new SRS inclusion criteria: age of 10 years and older at initiation of bracing; initial curve of 25 to 40 degrees; Risser sign 0 to 2; female; premenarcheal or less than 1 year past menarche; and no previous treatment. There were 48 patients in the TLSO group and 35 in the Providence group. The new SRS assessment criteria of effectiveness included the percentage of patients who had 5 degrees or less and 6 degrees or more of curve progression at maturity, the percentage of patients whose curve progressed beyond 45 degrees, the percentage of patients who had surgery recommended or undertaken, and a minimum of 2 years of follow-up beyond maturity in those patients who were thought to have been successfully treated. All patients are evaluated regardless of compliance (intent to treat).

RESULTS

There were no significant differences in age at brace initiation, initial primary curve magnitude, sex, or initial Risser sign between the 2 groups. In the TLSO group, only 7 patients (15%) did not progress (<or=5 degrees), whereas 41 patients (85%) progressed by 6 degrees or more, including the 30 patients whose curves exceeded 45 degrees. Thirty-eight patients (79%) required surgery. In the Providence group, 11 patients (31%) did not progress, whereas 24 patients (69%) progressed by 6 degrees or more, including 15 patients whose curves exceeded 45 degrees. Twenty-one patients (60%) required surgery. However, when the initial curve at initiation of bracing was 25 to 35 degrees, the results improved. Five (15%) of 34 patients in the TLSO group and 10 (42%) of 24 patients in the Providence group did not progress, whereas 29 patients (85%) and 14 patients (58%), respectively, progressed by 6 degrees or more, and 26 patients (76%) and 11 patients (46%), respectively, required surgery.

CONCLUSIONS

Using the new SRS bracing criteria, the Providence orthosis was more effective for avoiding surgery and preventing curve progression when the primary initial curves at bracing was 35 degrees or less. However, the overall success of orthotic management for AIS in both groups was inferior to previous studies. Our results raise the question of the effectiveness of orthotic management in AIS and support the need for a multicenter, randomized study using these new criteria.

Submuscular Isola rod with or without limited apical fusion in the management of severe spinal deformities in young children: preliminary report

STUDY DESIGN

Retrospective review of the results of submuscular rod placement with and without limited apical fusion for the treatment of severe spinal deformities in young children.

OBJECTIVES

To determine the success of this method for controlling severe deformities while allowing for spinal growth and to compare this method with previously reported results.

SUMMARY OF BACKGROUND DATA

A variety of methods for controlling scoliosis in young children have been reported, but complications including spontaneous fusion, loss of correction, instrumentation failure, and limited spinal growth are common.

METHODS

The cases of 29 young children with progressive scoliosis or kyphoscoliosis as a result of a variety of diagnoses treated with a submuscular Isola rod and a postoperative orthosis were retrospectively reviewed. Eleven patients also had a short anterior and posterior apical fusion or convex hemiepiphysiodesis to aid in correction and stabilization of their deformity. The remaining 18 patients had a submuscular rod only.

RESULTS

The mean age at surgery was 6.7 years (range, 1-11 years). The initial preoperative mean magnitude of the major curve was 66 degrees (range, 42-112 degrees ). After surgery this decreased to a mean of 38 degrees (range, 16-70 degrees ). The most recent radiographs demonstrated a mean 47 degrees curve (range, 28-79 degrees ). The mean number of lengthenings per patient has been two (range, 0-5). Nine patients have reached a suitable age and have been converted to a posterior spinal fusion and segmental spinal instrumentation. Nine complications have occurred in seven patients (24%). These included five hook displacements and three rod breakages. These were treated by hook reinsertion and rod exchange or sleeve and a repeat lengthening. There was one superficial infection treated medically.

CONCLUSION

This technique is useful in the management of severe spinal deformities in young children who have either failed, or have a contraindication to, orthotic management. Complications are relatively frequent but well tolerated.

Assessment of non-mydriatic fundus photography in detection of diabetic retinopathy

Non-mydriatic retinal photography with later interpretation of the photographs was assessed as a screening method for the detection of diabetic retinopathy; when compared with an ophthalmologist's clinical assessment in a random group of 62 diabetic patients it was accurate (false negative 6.8%, false positive 2%) and sensitive (sensitivity 96%, specificity 98%). The assessment of further management required based on analysis of the photographs was 96.5% in agreement with the further management suggested by the ophthalmologist after direct clinical assessment of the patient. If this technique were used to screen patients in a typical diabetic clinic the predicted positive accuracy rate would be 84% and the predicted negative accuracy rate 99.5%.

Sequences flanking the centromere of human chromosome 10 are a complex patchwork of arm-specific sequences, stable duplications and unstable sequences with homologies to telomeric and other centromeric locations

Little is known about sequence organization close to human centromeres, despite empirical and theoretical data which suggest that it may be unusual. Here we present maps which physically define large sequence duplications flanking the centromeric satellites of human chromosome 10, together with a fluorescence in situ hybridization (FISH) analysis of pericentromeric sequence stability. Our results indicate that the duplications on each chromosome arm are organized into two blocks of approximately 250 and 150 kb separated by approximately 300 kb of non-duplicated DNA. The larger proximal blocks, containing ZNF11A, ZNF33A and ZNF37A (10p11) and ZNF11B, ZNF33B and ZNF37B (10q11), are inverted. However, the smaller distal blocks, containing D10S141A (10p11) and D10S141B (10q11), are not. A primate FISH analysis indicates that these loci were duplicated before the divergence of orang-utans from other Great Apes, that a cytogenetically cryptic pericentric inversion may have been involved in the formation of the flanking duplications and that they have undergone further rearrangement in other primate species. More surprising is the fact that sequences across the entire pericentromeric region appear to have undergone unprecedented levels of duplication, transposition, inversion and either deletion or sequence divergence in all primate species analysed. Extrapolating our data to the whole genome suggests that a minimum of 50 Mb of DNA in centromere-proximal regions is subject to an elevated level of mechanistically diverse sequence rearrangements compared with the bulk of genomic DNA.