CD133-Dependent Activation of Phosphoinositide 3-Kinase /AKT/Mammalian Target of Rapamycin Signaling in Melanoma Progression and Drug Resistance

Melanoma frequently harbors genetic alterations in key molecules leading to the aberrant activation of PI3K and its downstream pathways. Although the role of PI3K/AKT/mTOR in melanoma progression and drug resistance is well documented, targeting the PI3K/AKT/mTOR pathway showed less efficiency in clinical trials than might have been expected, since the suppression of the PI3K/mTOR signaling pathway-induced feedback loops is mostly associated with the activation of compensatory pathways such as MAPK/MEK/ERK. Consequently, the development of intrinsic and acquired resistance can occur. As a solid tumor, melanoma is notorious for its heterogeneity. This can be expressed in the form of genetically divergent subpopulations including a small fraction of cancer stem-like cells (CSCs) and non-cancer stem cells (non-CSCs) that make the most of the tumor mass. Like other CSCs, melanoma stem-like cells (MSCs) are characterized by their unique cell surface proteins/stemness markers and aberrant signaling pathways. In addition to its function as a robust marker for stemness properties, CD133 is crucial for the maintenance of stemness properties and drug resistance. Herein, the role of CD133-dependent activation of PI3K/mTOR in the regulation of melanoma progression, drug resistance, and recurrence is reviewed.

Mechanisms of Melanoma Progression and Treatment Resistance: Role of Cancer Stem-like Cells

Melanoma is the third most common type of skin cancer, characterized by its heterogeneity and propensity to metastasize to distant organs. Melanoma is a heterogeneous tumor, composed of genetically divergent subpopulations, including a small fraction of melanoma-initiating cancer stem-like cells (CSCs) and many non-cancer stem cells (non-CSCs). CSCs are characterized by their unique surface proteins associated with aberrant signaling pathways with a causal or consequential relationship with tumor progression, drug resistance, and recurrence. Melanomas also harbor significant alterations in functional genes (BRAF, CDKN2A, NRAS, TP53, and NF1). Of these, the most common are the BRAF and NRAS oncogenes, with 50% of melanomas demonstrating the BRAF mutation (BRAFV600E). While the successful targeting of BRAFV600E does improve overall survival, the long-term efficacy of available therapeutic options is limited due to adverse side effects and reduced clinical efficacy. Additionally, drug resistance develops rapidly via mechanisms involving fast feedback re-activation of MAPK signaling pathways. This article updates information relevant to the mechanisms of melanoma progression and resistance and particularly the mechanistic role of CSCs in melanoma progression, drug resistance, and recurrence.

Tumor Microenvironment as a Therapeutic Target in Melanoma Treatment

The role of the tumor microenvironment in tumor growth and therapy has recently attracted more attention in research and drug development. The ability of the microenvironment to trigger tumor maintenance, progression, and resistance is the main cause for treatment failure and tumor relapse. Accumulated evidence indicates that the maintenance and progression of tumor cells is determined by components of the microenvironment, which include stromal cells (endothelial cells, fibroblasts, mesenchymal stem cells, and immune cells), extracellular matrix (ECM), and soluble molecules (chemokines, cytokines, growth factors, and extracellular vesicles). As a solid tumor, melanoma is not only a tumor mass of monolithic tumor cells, but it also contains supporting stroma, ECM, and soluble molecules. Melanoma cells are continuously in interaction with the components of the microenvironment. In the present review, we focus on the role of the tumor microenvironment components in the modulation of tumor progression and treatment resistance as well as the impact of the tumor microenvironment as a therapeutic target in melanoma.

The Effect of Patient Positioning on Intraoperative Neuromonitoring During Thyroid and Parathyroid Surgery

BACKGROUND

Intraoperative neuromonitoring (IONM) has been accepted as a routine adjunct among surgeons who perform thyroid and parathyroid surgeries. Thyroid and parathyroid surgeries use various patient positioning strategies that have poorly understood effects on IONM. The aim of this study was to compare IONM signals between the transaxillary and transcervical approaches.

METHODS

In this retrospective cohort study, we evaluated 463 adult patients who underwent a total of 502 procedures. The procedures performed included total thyroidectomy, right or left hemithyroidectomy, and parathyroidectomy. Vagus nerve and recurrent laryngeal nerve (RLN) latency and amplitude measurements were analyzed intra-operatively. The distances between the vagus nerve and the trachea were measured via ultrasound during transaxillary procedures.

RESULTS

Compared to the transcervical approach, the right vagus nerve latency was significantly decreased in the transaxillary approach. Transaxillary surgery was not associated with increased latency or decreased amplitude on IONM. The distance between the vagus nerve and trachea was significantly decreased post-positioning during transaxillary approaches.

DISCUSSION

Despite differences in patient positioning, a transaxillary approach was not associated with increased stress on the vagus nerve or RLN, according to IONM data. The decreased right vagus nerve latency associated with a transaxillary approach highlights the importance of considering patient positioning and laterality while interpreting IONM data.

Effects of Parathyroidectomy on Normocalcemic Primary Hyperparathyroidism and the Role of Intraoperative PTH Measurement

BACKGROUND

Normocalcemic primary hyperparathyroidism (NCpHPT) and normohormonal primary hyperparathyroidism (NHpHPT) are recently recognized variants of primary hyperparathyroidism. Current guidelines for the management hyperparathyroidism recognize NCpHPT as one of the areas that are recommended for more research due to limited available data.

METHODS

A retrospective review of patients who had parathyroidectomy between 2014 and 2019. We excluded patients with multiple endocrine neoplasia syndromes and secondary and tertiary hyperparathyroidism. Included patients were classified based on the biochemical profile into classic or normocalcemic hyperparathyroidism group. Collected data included demographics, preoperative localizing imaging, intraoperative parathyroid hormone levels, and postoperative cure rates.

RESULTS

261 patients were included: 160 patients in the classic and 101 patients in the normocalcemic group. Patients in the normocalcemic group had significantly more negative sestamibi scans (n = 58 [8.2%] vs 78 [51.3%], P = <.01), smaller parathyroid glands (mean weight 436.0 ± 593.0 vs 742.4 ± 1109.0 mg, P = .02), higher parathyroid hyperplasia rates (n = 51 [50.5%] vs 69 [43.1%]), and significantly higher intraoperative parathyroid hormone at 10 minutes (78.1 ± 194.6 vs 43.9 ± 62.4 1, P = .04). Positive predictive value of both intraoperative parathyroid hormone and cure rate was lower in the normocalcemic group (84.2% vs 95.7%) and (80.5% vs 95%), respectively.

CONCLUSION

Normocalcemic hyperparathyroidism is a challenging disease. Surgeons should be aware of the lower cure rate in this group, interpret intraoperative parathyroid hormone with caution, and have a lower threshold for bilateral neck exploration and 4 glands visualization.

A Single Surgeon's 10-Year Experience in Remote-Access Thyroid and Parathyroid Surgery

BACKGROUND

Remote-access thyroid and parathyroid surgery has gained popularity recently due to its benefit of avoiding visible neck scars. Most of these techniques were described and performed in Asia, on patients with different body habitus compared to American patients. We aim to analyze the learning curve in performing these operations in North America. .

METHODS

This is a retrospective cohort study of a 10-year experience by a single surgeon at a North American institute. Patients who underwent thyroid or parathyroid procedures by a transaxillary, retroauricular, or transoral endoscopic thyroidectomy vestibular approach (TOETVA) were included. Cumulative sum (CUSUM) was used to analyze learning curves based on intraoperative blood loss and total operative times and learning phases were divided accordingly.

RESULTS

Three hundred seventy-two remote-access thyroid and parathyroid procedures were performed during the study period. Total operative time for transaxillary procedures was initially reduced after the 69th procedure and then again after the 134th case. For retroauricular procedures, marked reduction in the operative time was observed after 21 procedures. Most patients (57.02%) were discharged home on the same day during the mastering phase. In the transaxillary procedures, only 1 case of brachial plexus injury occurred prior to the routine use of somatosensory evoked potential (SSEP) monitoring.

DISCUSSION

Remote-access thyroid and parathyroid surgeries can be performed safely with minimal complications in a select group of patients. Analysis of the learning curve in performing these operations aids in structuring a safe and effective learning period for endocrine surgeons seeking to venture into this modality of treatment.

Robotic and Laparoscopic Approaches for Adrenal Surgery in Obese Patients

OBJECTIVE

Minimally invasive adrenalectomy is a challenging procedure in obese patients. Few recent studies have advocated against robot-assisted adrenalectomy, particularly in obese patients. This study aims to compare operative outcomes between the robotic and laparoscopic adrenalectomy, particularly in obese patients.

MATERIALS AND METHODS

A retrospective analysis was performed on all consecutive patients undergoing adrenalectomy for benign disease by a single surgeon using either a laparoscopic or robotic approach. Adrenal surgeries for adrenal cancer were excluded. Demographics, operative time, length of hospital stays, estimated blood loss (EBL), and intraoperative and postoperative complications were evaluated. Patients were divided into 2 groups; obese and nonobese. A sub-analysis was performed comparing robotic and laparoscopic approaches in obese and nonobese patients.

RESULTS

Out of 120, 55 (45.83%) were obese (body mass index ≥ 30 kg/m²). 14 (25.45%) of the obese patients underwent a laparoscopic approach, and 41 (74.55%) underwent a robotic approach. Operative times were longer in the obese vs. nonobese groups (173.30 ± 72.90 minutes and 148.20 ± 61.68 minutes, P = .04) and were associated with less EBL (53.77 ± 82.48 vs. 101.30 ± 122, P = .01). The robotic approach required a longer operative time when compared to the laparoscopic approach (187 ± 72.42 minutes vs. 126.60 ± 54.55 minutes, P = .0102) in the obese but was associated with less blood loss (29.02 ± 51.05 mL vs. 138.30 ± 112.20 mL, P < .01) and shorter hospital stay (1.73 ± 1.23 days vs. 3.17 ± 1.27 days, P < .001).

CONCLUSION

Robot-assisted adrenal surgery is safe in obese patients and appears to be longer; however, it provides improvements in postoperative outcomes, including EBL and shorter hospital stay.

Ultrasound Elastography Predicts Thyroid Nodule Volume Reduction Rate After Percutaneous Ethanol Ablation

OBJECTIVES

To evaluate the safety and efficacy of percutaneous ethanol ablation (PEA) on indeterminate thyroid nodules (Bethesda III and IV) based on ultrasound (US) elastography by assessing the volume reduction rate (VRR), relative reduction in size, resolution of compressive symptoms, and post-procedural complications.

MATERIALS AND METHODS

This is a retrospective cohort study of all thyroid nodules treated with PEA by a single surgeon at a North American tertiary referral center. Study variables included demographics, nodule characteristics, Bethesda classification, US elastography, presence of compressive symptoms, thyroid function, and post-procedural complications. Relative volume reductions and VRR were calculated at 3- and 6-month follow-ups.

RESULTS

Thirty-four thyroid nodules were evaluated in 22 patients. All thyroid nodules underwent a fine needle aspiration prior to PEA. After 6 months, 45% of all thyroid nodules exhibited a VRR of ≥50%. A significant VRR was achieved in the soft thyroid nodules at 6 months (42.15% ± 31), compared to the stiff nodules with 30.92% ± 91.53, P < .05. Post-PEA thyroid stimulating hormone levels did not significantly change after the procedure. Compressive symptoms resolved in all 5 patients who reported it. One patient developed transient vocal cord paresis that resolved in 3 months.

DISCUSSION

To the best of our knowledge, this is the largest series of PEA for thyroid nodules in North America. Ultrasound elastography is a useful adjunct in predicting the success of PEA for nonmalignant thyroid nodules. Percutaneous ethanol ablation is both a safe and effective alternative to surgery for relief of compressive symptoms in select patients.

MIS Distal Metatarsal Metaphyseal Osteotomy in the treatment of metatarsalgia: MOXFQ patient reported outcomes

INTRODUCTION

The aim of this paper is to present validated patient reported outcomes for MIS Distal Metatarsal Metaphyseal Osteotomy (DMMO) in the treatment of metatarsalgia. The study aims to evaluate the DMMO procedure, report patient satisfaction with the operated foot and report any complications of this procedure.

PATIENTS AND METHODS

Between 2014 and 2016, patients who had failed conservative treatment for metatarsalgia were identified in the orthopaedic outpatient clinic. Twenty four consecutive patients requiring DMMO plus/minus toe straightening were prospectively studied. Patients requiring additional procedures at the time of surgery were excluded. Patients completed the validated Manchester-Oxford Foot Questionnaire (MOXFQ) three weeks pre-operatively and 1 year postoperatively. The MOXFQ results were analysed using Paired t-tests. A supplementary question was asked regarding patient satisfaction with the operated foot.

RESULTS

There were 20 women and 4 men with a mean age of 64 years (sd 8.6). Statistically significant differences were found between the pre and postoperative MOXFQ. The postoperative MOXFQ score demonstrated a poorer result for two patients, no change for two patients and improvement in 20 patients, with four of these patients recording the lowest possible score. There was a 29.5 point improvement in mean metric MOXFQ Index score. Seventy-nine percent (n = 19) of patients were satisfied or very satisfied with the operated foot. The average recoil of the metatarsal heads following DMMO was M2 4.01 mm, M3 4.55 mm, M4 4.16 mm. There was one delayed union and no non-unions. Further reported complications were a gastric bleed, pulmonary embolism (VTE), and one intra operative broken burr.

CONCLUSION

Our study demonstrates a clinically important and statistically significant improvement in patient reported outcomes following DMMO, with 79% of patients satisfied or very satisfied with this procedure. The average recoil of the metatarsal heads following DMMO was M2 4.01 mm, M3 4.55 mm, M4 4.16 mm with one delayed union and no non-unions.

Impact of surgery versus medical management on cardiovascular manifestations in Graves disease

BACKGROUND

Graves disease is well known to have multiple adverse effects on the cardiovascular system. We compared the cardiovascular outcomes after surgical intervention versus medical treatment in patients with Graves disease.

METHODS

We performed a retrospective study of all Graves disease patients with a cardiovascular comorbidity who underwent either surgical or medical management (N = 151). Perioperative biochemical and cardiovascular outcomes from the surgical versus the medical groups were analyzed.

RESULTS

Of 151 patients, 69 (45.6%) patients underwent total thyroidectomy and 82 (54.3%) patients received medical treatment. Hypertension resolved in 44.7% of the patients from the surgical group vs 18% in the medical group (P = .03). Tachyarrhythmias, including atrial fibrillation and tachycardia, improved in 85.9% of patients in the surgical group vs 66% in the medical group (P = .01). All cardiovascular manifestations examined, hypertension, tachyarrhythmias, and heart failure, improved in 69% of patients in the surgical group and 42.6% of patients in the medical group during the follow-up period (P < .01).

CONCLUSION

Surgical treatment offers a significant and rapid clinical improvement of cardiovascular manifestations in Graves disease patients, such as hypertension, tachyarrhythmias, and heart failure. Surgery should be considered and recommended in Graves disease patients with known cardiovascular manifestations.

Nuclear morphometry in indeterminate thyroid nodules

Background

Up to 30% of thyroid nodules undergoing fine needle aspiration (FNA) yield an indeterminate result. Recent research efforts have suggested that nuclear morphometry and morphology may enhance the diagnostic accuracy of FNA as an objective adjunct. We applied nuclear morphometric analysis on a diverse cohort of patients to evaluate the association between nuclear morphometry and malignancy.

Methods

Forty-five randomly selected patients, who underwent thyroid surgery after an indeterminate FNA result (Bethesda III & IV) between 2012-2015, were reviewed. One hundred representative nuclei per FNA of a thyroid nodule were analyzed using ImageJ. Seven validated morphometric parameters were collected: nuclear area, perimeter, circularity, aspect ratio, roundness, and maximum/minimum Feret's diameter. L/S ratio was subsequently calculated. All 8 nuclear parameters were reported as averages with standard errors of the mean (SEM). A Student's t-test was used to assess the association of nuclear parameters with final surgical pathology.

Results

The mean age of all patients was 56.31±15.39 years, with female patients comprising 68.9% of the cohort. Twenty-two patients had malignant thyroid nodules. The mean perimeter of nuclei for the cohort was 18.48±0.45 µm, the mean area was 22.19±0.93 µm, and the mean maximum Feret's diameter was 6.67±0.13 µm. No significant differences in the 8 nuclear parameters were observed between the malignant and non-malignant groups.

Conclusions

In the population examined, our results suggest that nuclear morphometry is not yet a tool of reliable diagnostic value in accessing malignant and non-malignant thyroid nodules. Further investigation is necessary to identify objective parameters that will enhance diagnostic accuracy of indeterminate FNA cytology to minimize the number of diagnostic thyroid surgery.

Efficacy of indocyanine green fluorescence in predicting parathyroid vascularization during thyroid surgery

BACKGROUND

We examined the value of indocyanine green (ICG) fluorescence angiography in predicting parathyroid vascularization following thyroid and central compartment surgeries.

METHODS

Data were prospectively collected on adult patients undergoing thyroid and/or central compartment surgeries. Outcomes were compared in surgeries performed with and without ICG use. ICG scoring was used to quantify the vascularity of parathyroid glands.

RESULTS

One hundred eleven patients were included; 43 (38.7%) patients underwent ICG injections. There was no significant difference in mean parathyroid hormone (PTH) changes at the end of surgery (29.24 vs 23.48 pg/mL, P = .38), symptomatic hypocalcemia (7.9% vs 3.9%, P = .37), or length of stay (1.095 ± 0.22 vs 0.912 ± 0.07 days, P = .51) between surgeries performed with and without ICG. The average vascularization score among individuals undergoing ICG angiography was 2.89 out of a maximum of 8 points.

CONCLUSION

Low-flow ICG patterns are not associated with postoperative PTH changes or transient hypocalcemia and may lead to unnecessary parathyroid autotransplantation.

Thyroid surgery and obesity: Cohort study of surgical outcomes and local specific complications

INTRODUCTION

Obesity is associated with numerous complications after elective general surgeries. The aim is to compare surgical outcomes and local specific complications in obese and non-obese patients after thyroid surgery.

METHODS

Retrospective study over a 3-year period at a North American academic institution. Outcome measures were operative time, estimated blood loss, hospital length of stay, and local specific complications (hypocalcemia, recurrent laryngeal nerve injury, wound hematoma, wound seroma, and chyle leakage).

RESULTS

A total of 469 patients were included (mean [SD] age, 50.11 [15.01] years; mean [SD] BMI, 30.5 [8.3] kg/m²; 207 [44.14%] obese). There was no difference in operative time (125.7 vs. 129.6, p = 0.52), estimated blood loss (16.88 vs. 14.56, p = 0.28), or hospital length of stay (0.95 vs. 0.95, p = 0.96). Overall, there was no difference in the rates of local specific complications between the two groups.

CONCLUSIONS

Obesity is not associated with adverse outcomes in patients undergoing thyroid surgery.

Well-differentiated thyroid cancer and robotic transaxillary surgery at a North American institution

BACKGROUND

Recent studies from Asia have reported the safety and feasibility of robotic-assisted thyroid surgery. In the United States, several small series and case reports have been published, mostly regarding treatment of benign disease. The aim of our study is to report the safety and feasibility of robotic surgery for well-differentiated thyroid cancer patients at a North American institution.

MATERIALS AND METHODS

We performed a retrospective cohort study using a prospectively collected single-center clinical database at Tulane University Medical Center. We included all well-differentiated thyroid cancer patients who underwent robotic-assisted or conventional cervical approach thyroid surgery with or without lymph node dissections at our institution from January 2015 to June 2017. Patient demographics and perioperative data were collected and analyzed.

RESULTS

A total of 144 surgeries for thyroid cancer were performed; 35 (24.3%) were robotic-assisted. There were no significant differences in estimated blood loss, operative times, complication rates, specimen sizes, positive microscopic margins, number of lymph nodes removed with associated lymph node dissections, patient follow-up duration, or clinical recurrence rates between the two groups. Overall length of stay was shorter for robotic-assisted surgery, at 0.6 ± 0.9 d, versus 1.1 ± 1.2 d for conventional open surgery (P = 0.009). For robotic-assisted surgery, 19 patients (54.3%) were discharged on the day of procedure, and only one patient was admitted as inpatient to the hospital (2.9%).

CONCLUSIONS

Robot-assisted thyroid surgery is a safe, feasible, and oncologically sound approach for a select group of well-differentiated thyroid cancer patients. However, long-term studies are needed.

Outcomes following excision of Morton's interdigital neuroma: a prospective study

AIMS

This is the first prospective study to report the pre- and post-operative patient reported outcomes and satisfaction scores following excision of interdigital Morton's neuroma.

PATIENTS AND METHODS

Between May 2006 and April 2013, we prospectively studied 99 consecutive patients (111 feet) who were to undergo excision of a Morton's neuroma. There were 78 women and 21 men with a mean age at the time of surgery of 56 years (22 to 78). Patients completed the Manchester-Oxford Foot Questionnaire (MOXFQ), Short Form-12 (SF-12) and a supplementary patient satisfaction survey three months pre-operatively and six months post-operatively.

RESULTS

Statistically significant differences were found between the mean pre- and post-operative MOXFQ and the physical component of the SF-12 scores (p = 0.00081 and p = 0.00092 respectively). Most patients reported their overall satisfaction as excellent (n = 49, 49.5%) or good (n = 29, 29.3%), but ten patients were dissatisfied, reporting poor (n = 8, 8.1%) or very poor (n = 2, 2.0%) results. Only 63 patients (63%) were pain-free at follow-up: in eight patients (8.1%), the MOXFQ score worsened. There was no statistically significant difference in outcome between surgery on single or multiple sites. However, the MOXFQ scores were significantly worse after revision surgery (p = 0.004).

CONCLUSIONS

The patient-reported outcomes after resection of a symptomatic Morton's neuroma are acceptable but may not be as good as earlier studies suggest. Surgery at several sites can be undertaken safely but caution should be exercised when considering revision surgery. Cite this article: Bone Joint J 2016;98-B:1376-81.

Effect of immune-enhancing diets on the outcomes of patients after major burns

The use of immune-enhancing diets (IEDs) has been shown to be beneficial in some categories of critically ill patients. This study aimed to evaluate the effect of early enteral feeding supplemented with glutamine and omega-3 fatty acids, as immune-enhancing diets, on the outcomes of patients after major burns. Forty thermally injured adult patients with 30-50% total body surface area (TBSA) burns, including deep areas ranging from 5-20%, were randomized into a prospective, double-blind, controlled clinical trial. They were placed into two equal groups: group A (IED group), in which patients received early enteral feeding supplemented with glutamine and omega-3 fatty acids as immune-enhancing diets; and group B (control group), in which patients received early enteral feeding not supplemented with immune-enhancing diets. Laboratory assessment of serum albumin, serum C-reactive protein, total lymphocytic count and serum immunoglobulins (IgA, IgG and IgM) was performed at admission, and on days 4, 7 and 14. Finally, outcomes were assessed by monitoring the survival rate, the length of hospital stay and the incidence of infection. There were no significant differences between the IED and control group regarding age (28.7±5.32 versus 29.85±5.94), sex, weight, %TBSA (37.75±4.4 versus 38.3±4.84) and %burn depth (11.7±2.36 versus 10.7±2.036). The incidence of infection (2 versus 8) and the length of hospital stay (16.3±0.92 days versus 17.95±2.96 days) were decreased significantly in the IED group versus the control group. There was no significant difference between the survival rates in both groups as there was only one death in the control group. Thanks to IEDs, patient outcome was improved and infectious morbidity and length of hospital stay were reduced, but there was no effect on the survival rates following major burns.

Identification of mealybug pest species (Hemiptera: Pseudococcidae) in Egypt and France, using a DNA barcoding approach

Pseudococcidae (mealybugs) is a large taxonomic group, including a number of agronomic pests. Taxonomic identification of mealybug species is a recurrent problem and represents a major barrier to the establishment of adequate pest management strategies. We combined molecular analysis of three DNA markers (28S-D2, cytochrome oxidase I and internal transcribed spacer 2) with morphological examination, for the identification of 176 specimens collected from 40 mealybug populations infesting various crops and ornamental plants in Egypt and France. This combination of DNA and morphological analyses led to the identification of 17 species: seven in Egypt (Planococcus citri (Risso), Planococcus ficus (Signoret), Maconellicoccus hirsutus (Green), Ferrisia virgata (Cockerell), Phenacoccus solenopsis Tinsley, Phenacoccus parvus Morrison and Saccharicoccus sacchari (Cockerell)) and 11 in France (Planococcus citri, Pseudococcus viburni Signoret, Pseudococcus longispinus (Targioni-Tozzetti), Pseudococcus comstocki (Kuwana), Rhizoecus amorphophalli Betrem, Trionymus bambusae (Green), Balanococcus diminutus (Leonardi), Phenacoccus madeirensis Green, Planococcus vovae (Nasonov), Dysmicoccus brevipes (Cockerell) and Phenacoccus aceris Signoret), Pl. citri being found in both countries. We also found genetic variation between populations considered to belong to the same species, justifying further investigation of the possible occurrence of complexes of cryptic taxa.

Femoral lengthening with the Intramedullary Skeletal Kinetic Distractor

Femoral lengthening using the Intramedullary Skeletal Kinetic Distractor is a new technique. However, with intramedullary distraction the surgeon has less control over the lengthening process. Therefore, 33 femora lengthened with this device were assessed to evaluate the effect of operative variables under the surgeon’s control on the course of lengthening. The desired lengthening was achieved in 32 of 33 limbs. Problems encountered included difficulty in achieving length in eight femora (24%) and uncontrolled lengthening in seven (21%). Uncontrolled lengthening was more likely if the osteotomy was placed with less than 80 mm of the thick portion of the nail in the distal fragment (p = 0.052), and a failure to lengthen was more likely if there was over 125 mm in the distal fragment (p = 0.008). The latter problem was reduced with over-reaming by 2.5 mm to 3 mm. Previous intramedullary nailing also predisposed to uncontrolled lengthening (p = 0.042), and these patients required less reaming.

Using the Intramedullary Skeletal Kinetic Distractor, good outcomes were obtained; problems were minimised by optimising the position of the osteotomy and the amount of over-reaming performed.

Limb salvage for osteosarcoma of the distal tibia with resection arthrodesis, autogenous fibular graft and Ilizarov external fixator

We report the results of limb salvage for non-metastatic osteosarcoma of the distal tibia using resection arthrodesis, autogenous fibular graft and fixation by an Ilizarov external fixator.

In six patients with primary osteosarcoma of the distal tibia who refused amputation, treatment with wide en bloc resection and tibiotalar arthrodesis was undertaken. The defect was reconstructed using non-vascularised free autogenous fibular strut graft in three patients and a vascularised pedicular fibular graft in three, all supplemented with iliac cancellous graft at the graft-host junction. An Ilizarov external fixator was used for stabilisation of the reconstruction.

In five patients sound fusion occurred at a mean of 13.2 months (8 to 20) with no evidence of local recurrence or deep infection at final follow-up. The mean post-operative functional score was 70% (63% to 73%) according to the Musculoskeletal Tumour Society scoring system. All five patients showed graft hypertrophy.

Union of the graft was faster in cases reconstructed by vascularised fibular grafts. One patient who had a poor response to pre-operative chemotherapy developed local tumour recurrence at one year post-operatively and required subsequent amputation.

Microcurrent skin patches for postoperative pain control in total knee arthroplasty: a pilot study

Pain control following painful orthopaedic procedures such as total knee arthroplasty (TKA) is an ongoing challenge, as current pain management techniques often result in under-medication and/or complications. In a study designed to test the effect of the micro-current skin patch (MCT) on pain relief in patients following TKA, we followed 24 patients, randomly divided into two groups, one group receiving MCT plus tramadol hydrochloride (tramadol) for pain relief and a control group receiving only tramadol, for 10 days postoperatively. Tramadol was given intramuscularly in increment doses of 100 mg, as needed, for the duration of the study period. Pain was assessed daily using a visual analogue score (VAS). Other parameters, including the effect of MCT on the dose of tramadol needed for pain relief, the degree of wound healing measured at the end of the follow-up period, category of the wound 10 days postoperatively (1, 2 or 3) and total drain fluid volume, were also assessed. During the 10-day postoperative period there was a progressive decrease in pain in patients of both groups, however the patients of the MCT group showed a consistently lower VAS throughout the observation period, most markedly on those follow-up days with the highest pain scores in patients of the control group. This effect was monitored on the basis of the average dose of tramadol administered per day: 200.0+/-7.0 mg/day in the control group and 63.3+/-15.8 mg/day in the MCT group. Wound healing was better with the application of the MCT patch: grade 1 wounds were observed in 50% of the patients of the MCT group as compared to 8.3% in control group. The total drain volume was lower in patients of the MCT group compared to the controls (1020.8+/-211.6 and 1170.8+/-243.5 ml, respectively). None of the patients indicated that they wished to discontinue MCT therapy. This pilot study shows that MCT therapy led to better pain control with a markedly lower need for tramadol as compared to the control group. This better pain control was accompanied by a better healing of the wound and a lower drain volume.

Hepatitis C virus-specific B cell activation: IgG and IgM detection in acute and chronic hepatitis C

BACKGROUND/AIMS/METHODS

Immunological responses to hepatitis C virus infection have not been fully studied. In an attempt to clarify some immunopathogenetic aspects of B cell activation during acute and chronic hepatitis C virus infection and to identify markers of chronicity or of recovery, the humoral response in hepatitis C virus-infected patients was studied.

RESULTS

In children with acute jaundice, with negative markers of acute hepatitis A, B and E, six of 87 (6.9%) had detectable anti-HCV IgM, and only one (1.1%) had detectable anti-HCV IgG. In adults with acute jaundice, with negative markers of acute hepatitis A, B and E, ten of 23 (43.5%) had detectable anti-HCV IgM associated in eight patients with detectable anti-HCV IgG. In chronic hepatitis C virus-infected adult patients, all anti-HCV IgG seropositive, four of 14 (28%) patients had detectable HCV-IgM in serum. In vitro specific antibody production was inducible in a minority of patients. In acute and chronic hepatitis C virus-infection, IgM-HCV serology did not correlate with viremia as detected by polymerase chain reaction.

CONCLUSIONS

Therefore, the polymerase chain reaction remains at the moment the only direct marker to demonstrate hepatitis C virus viral replication in patients with acute and chronic hepatitis while anti-HCV IgM analysis alone has only a limited diagnostic value in hepatitis C virus-infection.

Comparison of Directigen FLU-A with viral isolation and direct immunofluorescence for the rapid detection and identification of influenza A virus

Directigen FLU-A, an enzyme immunoassay membrane test, was compared prospectively to isolation in cell culture and direct immunofluorescence (IF) for the detection of influenza A virus. One hundred ninety specimens were evaluated by Directigen FLU-A and cell culture; 184 of these specimens were also tested by direct IF. The sensitivity of Directigen FLU-A compared to isolation in cell culture and direct IF was 100%. The specificities of Directigen FLU-A compared to isolation and direct IF were identical, 91.6%. Fourteen specimens that were positive by Directigen FLU-A did not yield virus in culture; two of the specimens, however, were positive by direct IF, and four other specimens were not specimens of choice for the test. A positive Directigen result had positive predictive values of 62.6 and 75.0% compared to isolation and direct IF, respectively; a positive Directigen result with an intensity reading of 2+ or greater, however, had positive predictive values of 85 and 100% compared to isolation and direct IF, respectively. In all comparisons, the negative predictive value was 100%. There was no evidence that cross-reactivity occurred with non-influenza A antigens. Directigen FLU-A should serve as a convenient screening test for influenza A and as a rapid test supported by isolation in cell culture during an influenza outbreak.

Comparison of directigen RSV with viral isolation and direct immunofluorescence for the identification of respiratory syncytial virus

An enzyme immunoassay membrane test (Directigen RSV) for the detection of respiratory syncytial virus in clinical specimens was compared prospectively with isolation in cell culture and direct immunofluorescence (IF). A total of 315 nasopharyngeal wash specimens from pediatric patients were examined. Directigen RSV was 86.1% sensitive and 91.3% specific for specimens positive by isolation in cell culture and/or IF, with 88.6% agreement. The false-positive rate was 16%; 2 of 20 specimens giving false-positive reactions by Directigen RSV were true-positives by blocking assay. Twenty-seven specimens (8.5%) whose results were initially uninterpretable by Directigen RSV due to filtration difficulties were diluted and upon retesting produced acceptable results. Sixty-three viral isolates and/or IF identifications of virus antigens representing seven virus groups other than respiratory syncytial virus were also found; cross-reactions between Directigen RSV and other viruses were not observed. Directigen RSV will be useful as an immediate procedure and in facilities lacking a comprehensive virology laboratory.

Detection of Chlamydia trachomatis in adolescent females using direct immunofluorescence

Direct immunofluorescent slide tests for the detection of genital Chlamydia trachomatis have attracted considerable attention because of their speed and economy, but most evaluation trials have concentrated on adult, high-risk populations. Using 152 paired specimens, we compared the Syva Micro Trak direct specimen test with culture in a population of adolescent females attending a general adolescent medicine clinic. The direct slide test was 90 percent sensitive and 95 percent specific overall, with positive and negative predictive values of 74 percent and 98 percent, respectively. Prevalence by culture was 13 percent. Six of our 23 positive slide tests could not be confirmed by culture. A positive chlamydia culture was significantly associated with nonwhite race, a positive Gram's stain, and the presence of mucopurulent endocervical discharge, but not with oral contraceptive pill use, obstetrical history, Pap smear results, multiple sexual partners, coexisting vaginitis or gonorrhea, or a history of prior sexually transmitted diseases. The direct test appears to be an acceptable substitute for culture in higher prevalence adolescent settings and a useful screening adjunct in lower prevalence groups.