Enhancing Cranio-Maxillofacial Fracture Care in Low- and Middle-Income Countries: A Systematic Review

Background: Cranio-maxillofacial (CMF) injuries represent a significant challenge in low- and middle-income countries (LMICs), exacerbated by inadequate infrastructure, resources, and training. This systematic review aims to evaluate the current strategies and solutions proposed in the literature to improve CMF fracture care in LMICs, focusing on education, patient transfer, and off-label solutions. Methods: A comprehensive literature search was conducted using PubMed/Medline from January 2000 to June 2023. Studies were selected based on the Preferred Reporting Items for Systematic Review and Meta-analysis Statement (PRISMA). Solutions were categorized into three main areas: education (digital and on-site teaching, fellowships abroad), patient transfer to specialized clinics, and off-label/non-operative solutions. Results: Twenty-three articles were included in the review, revealing a consensus on the necessity for enhanced education and training for local surgeons as the cornerstone for sustainable improvements in CMF care in LMICs. Digital platforms and on-site teaching were identified as key methods for delivering educational content. Furthermore, patient transfer to specialized national clinics and innovative off-label techniques were discussed as immediate solutions to provide quality care despite resource constraints. Conclusions: Effective CMF fracture care in LMICs requires a multifaceted approach, prioritizing the education and training of local healthcare professionals, facilitated patient transfer to specialized centers, and the adoption of off-label solutions to leverage available resources. Collaborative efforts between international organizations, local healthcare providers, and educational institutions are essential to implement these solutions effectively and improve patient outcomes in LMICs.

Off-Label Use of an External Hand Fixator for Craniomaxillofacial Fractures-An Anatomical Feasibility Study

BACKGROUND

The lack of resources limits the treatment of craniomaxillofacial fractures (CMF) in low-income countries (LIC). Therefore, Barton bandages and/or interdental wiring are considered in these regions. Fracture reduction is maintained by permanent occlusion for 6 weeks, which often leads to limited compliance and dissatisfying results. The aim of this cadaver-based study is to evaluate the feasibility of the use of an external face fixator (EFF) for the treatment of CMF, its biomechanical values and to define the optimal pin insertion points and angles.

MATERIALS AND METHODS

An AO hand fixator was used. CMF of types Le Fort 1-3 with split fractures of the hard palate were treated with EFF on 13 anatomical specimens. Fractures were created using a chisel, and pins were placed in specific anatomical regions. The maximal pull-out force [N] of pins was analysed by a tensile force gauge, and Fmax of the mandibular pins was evaluated. Computer tomography scans were performed on the healthy, fractured and EFF-treated skulls.

RESULTS

The pull-out forces for the single pins were mandibular pins (n = 15, median 488.0 N), supraorbital pins (n = 15, median 455.0 N), zygomatic pins (n = 14, median 269.1 N), medial hard palate pins (n = 12, median 208.4 N) and lateral hard palate pins (n = 8, median 49.6 N).

CONCLUSIONS

The results indicate that the operation technique is feasible, and the stability of the EFF is sufficient for maintaining the reduction. The required pins can safely be inserted into the described areas with good reduction results. Using EFF offers a feasible alternative to the non-surgical treatment of CMF in LIC.

Supplementary orthopaedic screening for children and adolescents to prevent permanent skeletal deformities - protocol for the "OrthoKids" study

BACKGROUND

Skeletal deformities (SD) in children and adolescents can lead to arthritic conditions, impairment of quality of life, and high treatment costs in the long term. However, comprehensive data on the prevalence of SDs in children and adolescents are limited and it remains therefore unclear whether there is a healthcare gap. "OrthoKids" is a project that addresses this evidence gap by implementing an orthopaedic screening for children and adolescents that supplements existing detection examinations within statutory standard care in Germany.

OBJECTIVE

To detect SDs so that they can be treated as needed at an early stage.

METHODS

The implementation of the supplementary orthopaedic screening will be evaluated through an exploratory cohort study that is set up in the German state Baden-Wuerttemberg. 20,000 children and adolescents aged 10 to 14 years will be recruited as a prospective cohort. A retrospective control cohort will be formed based on claims data provided by two cooperating statutory health insurances (SHIs). Participating children and adolescents receive a one-time orthopaedic screening. If at least one SD is diagnosed, treatment will be provided as part of the statutory standard care. Within the scope of the project, a follow-up examination will be performed after one year. An IT-platform will complement the study. The primary outcome measure is the point prevalence of scoliosis, genu varum/valgum, hip dysplasia, and flat feet. Secondary outcome measures are (i) the point prevalence of further less common SDs, (ii) health-related quality of life (HRQoL), (iii) sports ability based on activity (physical/athletic), physical constraints, and (sports) injuries, as well as (iv) monetary consequences of the orthopaedic screenings' implementation. Implementation determinants will be evaluated, too.

DISCUSSION

If the supplementary orthopaedic screening proves to be viable, it could be considered as a supplementary examination for children and adolescents within the frame of SHI in Germany. This could relieve the burden of disease among children and adolescents with SDs. In addition, it could disburden SHIs in the medium to long term.

TRIAL REGISTRATION

The OrthoKids study was registered in the German Clinical Trials Registry (Deutsches Register Klinischer Studien (DRKS)) on 26th July 2022 under the number 00029057.

Effects of COVID-19 Infection on Spermatogenesis, Oxidative Stress and Erectile Function

BACKGROUND

Our aim was to evaluate the effect of COVID-19 infection on male fertility and sexual function.

METHODS

Thirty-one patients were investigated over a mean follow-up of 90 days (22-527) after a COVID-19 infection. Erectile dysfunction (ED), blood tests for sexual hormones, semen analysis including analysis of oxidative stress (OS), as well as COVID-19 antibody titer and the nasal COVID-19 PCR test were evaluated pre- and post-infection.

RESULTS

Five patients reported a mild de novo ED (16.13%). One patient had a de novo positive mixed antiglobulin reaction test after the infection. We found no significant difference between pre-COVID-19 and post-COVID-19 spermiogram parameters (p = 0.815). OS showed no significant association with COVID-19 infection, but with pathological spermiogram categories, sperm concentration, total sperm count, testis volume, FSH and testosterone.

CONCLUSION

COVID-19 infection does not appear to affect sperm quality and OS negatively in the intermediate term. Further investigations will be needed to assess the potential long-term effects of the infection and vaccination on male sexual function and fertility.

Renal Arteriovenous (AV) Fistula after High-Grade Blunt Renal Trauma Caused by Traffic Accidents

PURPOSE

To report a series of three patients with traumatic renal AV fistulas after blunt renal laceration.

METHODS

We retrospectively analyzed the renal trauma cases treated in the Department of Urology of Salzburg University Clinic during a time period of 10 years concerning traumatic AV fistula formation and other clinical parameters.

RESULTS

In total, 3 cases of traumatic AV fistula formation were identified in 106 blunt renal trauma patients (2.8%), with a mean age of 39 (17-56) years. All renal traumas were classified as American Association for the Surgery of Trauma (AAST) grade IV. Two patients were primarily treated with ureteral stent; one was managed conservatively. All AV fistulas were diagnosed after a mean time of 7 (1-13) days. Two patients were symptomatic with gross hematuria, and the mean time between trauma and onset of symptoms was 11 (9-13) days. All cases were managed via coil embolization after a mean of 10 (8-13) days. Two patients received a second intervention after a mean of 18 (11-25) days. The mean AV fistula size was 18.7 (12-24) mm. Mean hemoglobin loss was 3.6 g/dL. One patient received one erythrocyte concentrate. Discharge was after a mean time of 13.3 (7-12) days, with the mean time of intensive care treatment being 2.3 (1-3) days.

CONCLUSIONS

Traumatic renal AV fistula is a rare but severe complication associated with higher-grade renal trauma. It can become evident through hematuria or blood loss several days after the initial trauma. The availability of coil embolization in a trauma center can help kidney preservation management.

The Antimicrobial Resistance (AMR) Rates of Uropathogens in a Rural Western African Area-A Retrospective Single-Center Study from Kpando, Ghana

Little is known about the antimicrobial resistance (AMR) status of uropathogens in Western Africa. We performed a retrospective evaluation of urine cultures collected from the rural Margret Marquart Catholic Hospital, Kpando, Ghana during the time period from October 2019−December 2021. Urine samples from 348 patients (median age 40 years, 52.6% male) were examined. Of these, 125 (35.9%) showed either fungal or bacterial growth, including Escherichia coli in 48 (38.4%), Candida species (spp.) in 29 (23.2%), Klebsiella spp. in 27 (21.6%), Proteus spp. in 12 (9.6%), Citrobacter spp. in 10 (8.0%), Salmonella spp. in 4 (3.2%), Staphylococcus spp. in 3 (2.4%), and Pseudomonas spp. in 2 (1.6%) cases. Two bacterial spp. were detected in 7 samples (5.6%). Antibiotic susceptibility testing showed resistance to a mean 8.6 out of 11 tested antibiotics per patient. Significant predictors (p < 0.05) of bacterial growth were age (OR 1.03), female sex (OR 3.84), and the number of pus cells (OR 1.05) and epithelial cells (OR 1.07) in urine microscopy. We observed an alarmingly high AMR rate among the uropathogens detected, even to reserve antibiotics. A similar resistance profile can be expected in West African patients living in high-income countries. These observations warrant the implementation of restrictive antibiotic protocols, together with the expansion of urine culture testing capacities, improvement of documentation and reporting of AMR rates, and continued research and development of new antibiotic therapies in order to stem the progression of AMR in this West African region.

Follow-Up Chest X-rays in Minor Chest Trauma with Fewer Than Three Rib Fractures: A Justifiable, Habitual Re-Imaging Industry?

Objective: We evaluated the necessity of follow-up chest X-rays (CXRs) to exclude a pneumothorax after 1 week of initial hospital presentation in patients with no signs of respiratory distress and fewer than three rib fractures. Materials and Methods: Adult patients with fewer than three fractured ribs who presented at our Level I trauma center between 2015 and 2017 were evaluated retrospectively. Patients with sternal fractures, who had suffered a polytrauma, or were primarily treated with a chest tube were excluded. The patients' and fractures' characteristics, trauma mechanism, median follow-up time, and the number of required secondary interventions were recorded. Results: This study included 249 patients, 137 (55.0%) of whom were male, with a median age of 64.34 years. In 150 patients (60.2%) one rib was affected, in 99 patients (39.8%) two ribs were affected, with the fractured ribs being true ribs (1-7) in 72 cases (28.9%), false ribs (8-12) in 151 cases (60.6%), and both in 26 cases (10.4%). The affected thorax half was the left side in 124 cases (49.8%) and both thorax halves in 4 cases (1.6%). The median follow-up time was 9 ± 4 days. In the follow-up CXRs, six patients (1.6%) required delayed intervention (tube thoracostomy): one case of hemopneumothorax and five cases of pneumothorax. All of the patients fully recovered. Conclusions: Planned CXR follow-ups revealed only a small number of complications that needed intervention and therefore seem not to be necessary. Symptom-triggered reappearance seems to be more sufficient and economical compared to habitual reimaging.

Neoadjuvant Chemotherapy before Nephroureterectomy in High-Risk Upper Tract Urothelial Cancer: A Systematic Review and Meta-Analysis

Simple Summary

In muscle-invasive bladder cancer, platinum-based neoadjuvant chemotherapy is a well-established concept, since it contributes to pathological downstaging and improves overall survival. Immunotherapy has become increasingly important in adjuvant and palliative treatment for metastatic urothelial carcinoma, and phase II studies have shown assuring data in neoadjuvant treatment before cystectomy. Although upper urinary tract urothelial cancer usually presents as more invasive at diagnosis than bladder cancer, there is no recommendation for neoadjuvant therapy before nephroureterectomy. This meta-analysis comprises eleven comparative trials on neoadjuvant chemotherapy in this setting and analyzes pathological downstaging as well as oncological outcomes. However, no comparative studies investigating immunotherapy in upper tract urothelial cancer were found. The pathological downstaging and complete response were significantly improved in patients who received neoadjuvant chemotherapy. The data also suggested a benefit in overall survival and progression-free survival in these patients. Prospective studies are needed to confirm these findings and assess the role of immunotherapy in this setting.

Abstract

Neoadjuvant chemotherapy is a well-established concept in muscle-invasive bladder cancer with known advantages in overall survival. Phase II trials show encouraging response rates for neoadjuvant immunotherapy before radical surgery in urothelial cancer. There is no recommendation for neoadjuvant therapy in upper tract urothelial carcinoma before nephroureterectomy. Our aim was to assess the available data on neoadjuvant chemotherapy and immunotherapy before nephroureterectomy in patients with high-risk upper tract urothelial carcinoma in terms of pathological downstaging and oncological outcomes. Two investigators screened PubMed/Medline for comparative trials in the English language. We identified 368 studies and included eleven investigations in a systematic review and meta-analysis for neoadjuvant chemotherapy and control groups. There were no comparative trials investigating immunotherapy in this setting. All 11 studies reported on overall pathological downstaging with a significant effect in favor of neoadjuvant chemotherapy (OR 5.17; 95%CI 3.82; 7.00). Pathological complete response and non-muscle invasive disease were significantly higher in patients receiving neoadjuvant chemotherapy (OR 12.07; 95%CI 4.16; 35.03 and OR 1.62; 95%CI 1.05; 2.49). Overall survival and progression-free survival data analysis showed a slight benefit for neoadjuvant chemotherapy. Our results show that neoadjuvant chemotherapy is effective in downstaging in upper urinary tract urothelial carcinoma. The selection of patients and chemotherapy regimens are unclear.

[Safety and efficacy of en bloc vs. conventional transurethral resection of bladder tumors: a meta-analysis and systematic review]

BACKGROUND

En bloc tumor resection of bladder tumors (ERBT) is a novel alternative procedure to conventional resection of bladder tumor (cTURBT), which might help to address common problems of the standard method, such as inadequate detrusor muscle in specimens, high re-resection rates and high recurrence rates.

OBJECTIVE

To analyze current data on ERBT in efficacy and safety compared to cTURBT.

DATA SOURCES

PubMed.

STUDY SELECTION

Two independent authors identified trials based on keywords and inclusion criteria. A third author was consulted in case of discrepancies. Screening keywords: ERBT, en bloc transurethral resection of bladder tumor, TURBT en bloc. A meta-analysis of 13 studies was performed. The effect size was estimated based on odds ratios and mean differences including their corresponding two-sided 95% confidence intervals.

DATA SYNTHESIS

The analyzed studies comprised a homogenous collective in terms of tumor size, tumor multiplicity and tumor stage. Operation time did not significantly differ between the methods. Differences were observed in hospitalization and catheterization time in favor of ERBT. Reported complications did not show clear differences. There was significantly more detrusor muscle in the specimens in the ERBT group. No significant differences were found in recurrence up to 2 years of follow-up.

CONCLUSION

ERBT is a safe alternative to conventional TURBT with promising features regarding effective resection of detrusor muscle. More standardized data on recurrence rates, different resection modalities and resection margin results are needed.

[Transurethral resection of bladder tumors (TURBT)]

Transurethral resection of bladder tumors (TURBT) is the standard of care for the diagnostics and primary treatment of bladder tumors. These are removed by fragmentation using loop diathermy. The resection area is coagulated for hemostasis. An important aspect is always a complete resection with an adequate amount of detrusor muscle in the specimen. Postoperative intravesical instillation of single-shot chemotherapy has been proven to reduce recurrence rates. Methods for improved tumor visualization (particularly photodynamic diagnostics) are used to enhance tumor detection rates particularly in multifocal tumors or carcinoma in situ (CIS). Thus, recurrence and progression rates can be reduced. Depending on the histological examination of the TURBT specimen, follow-up treatment for non-muscle invasive bladder tumors are adjuvant instillation treatment using chemotherapy or Bacillus Calmette-Guérin (BCG), second look TURBT and early cystectomy or for muscle invasive bladder tumors, radical cystectomy or (oncologically subordinate) trimodal treatment with renewed TURBT, radiotherapy and chemotherapy are indicated. Possible complications of TURBT include bleeding with bladder tamponade, extraperitoneal or intraperitoneal bladder perforation and infections of the urogenital tract.

On the black slope: analysis of the course of a blunt renal trauma collective in a winter sports region

Purpose

The aim of this study was to analyze the injury patterns and clinical course of a winter sport dominated by blunt renal trauma collective.

Methods

Blunt renal trauma cases (N = 106) treated in a Level 1 Trauma Center in Austria were analyzed.

Results

We encountered 12.3% grade 1, 10.4% grade 2, 32.1% grade 3, 38.7% grade 4 and 6.6% grade 5 renal traumata classified according to the American Association for the Surgery of Trauma (AAST). The mechanisms of injury (MOI) did not have an influence on the frequency of HG trauma (i.e., grade 4 and 5). No concomitant injuries (CIs) were found in 57.9% of patients. The number of patients without CIs was significantly higher in the sports associated trauma group compared to other MOIs (p < 0.01). In 94.3% the primary treatment was a non-operative management (NOM) including 56.6% conservative, 34.0% endourological, and 3.8% interventional therapies. A follow-up computed tomography (FU-CT) was performed in 81.1%, 3.3 days after trauma. After FU-CT, the primary therapy was changed in 11.4% of cases (grade ≥ 3). Comparing the Hb loss between the patients with grade 3 and 4 kidney trauma with and without revision surgery, we find a significantly increased Hb loss within the first 96 h after the trauma in the group with a needed change of therapy (p < 0.0001). The overall rate of nephrectomy (primary or secondary) was 9.4%. Independent predictors of nephrectomy were HG trauma (p < 0.01), age (p < 0.05), and sex (p < 0.05). The probability of nephrectomy was lower with (winter) sports-associated trauma (p < 0.1).

Conclusions

Sports-associated blunt renal trauma is more likely to occur isolated, and has a lower risk of severe outcomes, compared to other trauma mechanisms. NOM can successfully be performed in over 90% of all trauma grades.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-021-01830-w.

Electrosurgery or laser for benign prostatic enlargement: trumpcard or pitfalls

PURPOSE OF REVIEW

To summarize and comment on publications of the last 2 years in the field of endoscopic surgery for benign prostatic enlargement, focusing on similarities and differences of laser and electrosurgery.

RECENT FINDINGS

Because of good hemostasis and safety, invasive endoscopic surgery has evolved to a choice of treatment for vulnerable patients with ongoing antithrombotic medication and in same-day surgery. Recent publications show a good perioperative course and no deterioration in the postoperative outcome. Furthermore, alterations to the original surgical techniques of resection, enucleation, and vaporization have increased the preservation rate for antegrade ejaculation, advancing them to an appealing choice of treatment for sexually active men. Favorable outcomes can be achieved in both laser and electrosurgery. Only the choice of the surgical technique determines the outcome.

SUMMARY

Various invasive endoscopic surgical techniques are available, offering different advantages and disadvantages for the patient. All of them can be performed with laser and electrosurgery. Therefore, focusing on the proper choice of surgical technique instead of the energy source will guarantee the patient to benefit most.

Current Systemic Treatment Options in Metastatic Urothelial Carcinoma after Progression on Checkpoint Inhibition Therapy-A Systemic Review Combined with Single-Group Meta-Analysis of Three Studies Testing Enfortumab Vedotin

BACKGROUND

In the first and second-line therapy of metastatic urothelial carcinoma (mUC), checkpoint inhibitors (CPI) such as Pembrolizumab and Atezolizumab have been widely implemented. Little is currently known about what therapeutic options are effective after therapy with CPI. This article presents a systemic review of current treatment options in this setting.

METHODS

From August 2020 to 15 April 2021, a literature search was performed through the PubMed/Medline. Subsequently, a single-group meta-analysis of three studies testing Enfortumab vedotin (EV) was conducted.

RESULTS

Five therapy regimens tested in the post-CPI setting with adequate data were identified: Chemotherapy (CT), Ramucirumab plus Docetaxel, Erdafitinib (Erd), EV, and Sacituzumab govitecan (SG). In n = 74 + 125 + 288 patients, the single-group meta-analysis showed an objective response rate of 42.1% for EV compared to 17.9% for CT in a similar setting. EV was also ahead in progression free survival (5.9 months with EV vs. 3.7 months with CT) and overall survival (12.8 months with EV vs. 9.0 months with CT).

CONCLUSION

Most data are currently available for EV. Further research is needed on the question of which patients' subcollectives particularly benefit from which therapeutic approach.

Endoscopic enucleation of the prostate (EEP). The same but different-a systematic review

Purpose

Various techniques for EEP exist. They differ by surgical steps and the source of energy. It is assumed that the latter is of minor importance, whereas adherence to the anatomical enucleation template determines the postoperative result. So far, no systematic review highlights the differences between the energy sources in use for anatomical EEP. This study will address selfsame topic.

Methods

A systematic review of the literature was completed on September 1st, 2020. Studies comparing HoLEP, ThuLEP, DiLEP, or BipolEP with TUR-P providing 12 months of postoperative follow-up were included. Two frequentist network meta-analyses were created to compare the techniques of EEP indirectly.

Results

31 studies, including 4466 patients, were found eligible for our meta-analysis. Indirect pairwise comparison showed differences in surgery time between BipolEP and HolEP (MD − 16.72 min., 95% CI − 27.75 to − 5.69) and DiLEP and HoLEP (MD − 22.41 min., 95% CI − 39.43 to − 5.39). No differences in the amount of resected prostatic tissue, major and minor complications and postoperative catheterization time were found. The odds for blood transfusions were threefold higher for BipolEP than for HoLEP (OR 3.27, 95% CI 1.02–10.5). The difference was not statistically significant when comparing prospective trials and matched-pair analysis only (OR 3.25, 95% CI 0.94–11.18). The Qmax 12 months after surgery was 2 ml/sec. higher for BipolEP than for DiLEP (MD  2.00, 95% CI 0.17–3.84) and 1.94 ml/sec. lower for DiLEP than for HoLEP (MD − 1.94, 95% CI − 3.65 to − 0.22).

Conclusion

The energy source used for EEP has an impact on the intervention itself. BipolEP promotes surgical efficiency; laser techniques lower the risk of bleeding.

Registry

This meta-analysis is registered in the PROSPERO international prospective register registry with the registration number CRD42020205836.

Sperm banking before gonadotoxic treatment: is it worth the effort?

We aimed to compare the sperm quality in different cancer types and benign diseases before gonadotoxic treatment, and assess the usage rate of cryopreserved sperm for assisted reproductive treatment (ART). This retrospective study was conducted at two university clinics between January 2008 and July 2018. A total of 545 patients suffering from cancer or benign diseases were included in the study. The pretreatment sperm analyses were based on the World Health Organization (WHO) guidelines. Patients with testicular malignancy (TM) showed a significantly lower sperm count (median [interquartile range]: 18.7 × 10⁶ [5.3 × 10⁶–43.0 × 10⁶] ml⁻¹; P = 0.03) as well as total sperm count (42.4 × 10⁶ [13.3 × 10⁶–108.5 × 10⁶] per ejaculate; P = 0.007) compared to other malignant and benign diseases. In addition, patients with nonseminomatous TM showed the lowest sperm count (14.3 × 10⁶ [6.0 × 10⁶–29.9 × 10⁶] ml⁻¹, vs seminomas: 16.5 × 10⁶ [4.6 × 10⁶–20.3 × 10⁶] ml⁻¹; P = 0.001). With reference to the WHO 2010 guidelines, approximately 48.0% of the patients with TM and 23.0% with hematological malignancies (HM) had oligozoospermia. During the observation period, only 29 patients (5.3%) used their frozen sperms for 48 ART cycles, resulting in 15 clinical pregnancies and 10 live births. The sperm quality varies with the type of underlying disease, with TM and HM patients showing the lowest sperm counts. Due to the observed low usage rate of cryopreserved sperm, further patient interviews and sperm analyses should be included in the routine oncologic protocols to avoid unnecessary storage expenses. However, sperm banking is worth the effort as it provides hope for men who cannot reproduce naturally after gonadotoxic treatment.

Minimal-invasive management of urological complications after kidney transplantation

Kidney transplantation represents the gold standard treatment option for patients with end-stage renal disease. Improvements in surgical technique and pharmacologic treatment have continuously prolonged allograft survival in recent years. However, urological complications are frequently observed, leading to both postoperative morbidity and putative deterioration of allograft function. While open redo surgery in these patients is often accompanied by elevated surgical risk, endoscopic management of urological complications is an alternative, minimal-invasive option. In the present article, we reviewed the literature on relevant urological postoperative complications after kidney transplantation and describe preventive approaches during the pre-transplantation assessment and their management using minimal-invasive approaches.

Comparative study of a new commercial recombinant line assay and two immunoassays for detection of SARS-CoV-2 IgG antibodies in PCR-confirmed outpatients

Objectives

Commercially available immunoassays have been developed for detection of antibodies against SARS-CoV-2. However, equivocal and discrepant results between different immunoassay can occur requiring further assessment by confirmatory tests.

Methods

We investigated the new commercial line assay recomLine SARS-CoV-2 IgG (Mikrogen, containing the antigens S1, receptor-binding domain of the spike protein, and nucleocapsid protein (NP) of SARS-CoV-2) within a collection of well characterized serum samples from COVID-19 outpatients (n=49) and SARS-CoV-2-PCR-positive asymptomatic contact persons (n=6) in comparison to two commercial immunoassays, the S1 antigen based Anti-SARS-CoV-2-ELISA IgG by Euroimmun and the NP based Elecsys® Anti-SARS-CoV-2 by Roche.

Results

The recomLine assay was positive in all samples which had an equivocal or positive result for SARS-CoV-2 antibodies in at least one of the two immunoassays. It showed high agreement with the overall results of the immunoassays (94.5% [Cohen’s kappa = 0.85] and 92.7% [Cohen’s kappa 0.81] to the ELISA by Euroimmun and the assay by Roche, respectively). In addition, high agreement of the reactivity to the specific antigens S1 and NP in the recomLine assays compared to the results of the S1 based ELISA and NP based Elecsys® assay, was found (90.9% [Cohen’s kappa 0.78] and 96.4% [Cohen’s kappa 0.91] for S1 and NP, respectively).

Conclusions

The new recomLine SARS-CoV-2 IgG assay may be used as an additional tool for investigation of equivocal or discrepant results of Anti-SARS-CoV-2 immunoassays and for antigen-specific detection of SARS-CoV-2 IgG antibodies.

Evaluation of the SARS-CoV-2-IgG response in outpatients by five commercial immunoassays

Commercially available immunoassays have been developed for sensitive and specific detection of antibodies against SARS-CoV-2. While high sensitivity has been reported in hospitalized COVID-19 patients, little is known about the performance of the assays in ambulatory patients. Therefore, we evaluated the SARS-CoV-2-IgG response in 51 SASR-CoV-2-PCR-confirmed outpatients with five commercial immunoassays. The sensitivity in serum samples, collected at a median of 24 days after onset of symptoms, detected by the Anti-SARS-CoV-2-ELISA IgG (Euroimmun), EDI™ Novel Coronavirus COVID-19 IgG ELISA (Epitope Diagnostics), Liaison® SARS-CoV-2 S1/S2 IgG (Diasorin), SARS-CoV-2 IgG on the Architect™ i2000 (Abbott), and Elecsys® Anti-SARS-CoV-2 (IgM/IgA/IgG) on the cobas™ e801 (Roche) was 84.3%, 78.4%, 74.5%, 86.3%, and 88.2%, respectively. The sensitivity in serum samples, collected >20 days after onset of symptoms, varied between 75.0% and 90.0%, and in samples, collected at least 28 days after onset of symptoms, did not increase, except in the Anti-SARS-CoV-2-ELISA IgG by Euroimmun (90.0%). There was not an obvious association between the type of the antigen (N versus S protein) and the overall sensitivity of the assays. Our results show significant individual differences of the IgG response against SARS-CoV-2, additionally confirmed in three patients with follow-up serum samples and seven asymptomatic but PCR-positive contact persons. In conclusion, our study shows that commercially available immunoassays detect SARS-CoV-2-IgG or total antibodies in outpatients with a satisfying sensitivity, but lower than that reported for hospitalized patients. In asymptomatic persons the SARS-CoV-2-IgG response may even be absent in a relevant percentage of persons.

SARS-CoV-2-IgG response is different in COVID-19 outpatients and asymptomatic contact persons

Commercially available immunoassays have been developed for sensitive and specific detection of antibodies against SARS-CoV-2. While a fast and reliable IgG response has been reported for samples from hospitalized COVID-19 patients, less is known about ambulatory patients. We evaluated the SARS-CoV-2-IgG response by the Anti-SARS-CoV-2-ELISA IgG (Euroimmun) in a defined cohort of SARS-CoV-2-PCR-confirmed outpatients and asymptomatic contact persons including 137 serum samples from PCR-confirmed outpatients (n = 111) and asymptomatic but PCR-positive contact persons (n = 26) sent to our laboratory as part of routine diagnostics for determination of SARS-CoV-2-IgG. Overall positivity rate for SARS-CoV-2-IgG was 81.1 % in outpatients (irrespective of sampling before or after day 21 after onset of symptoms) but significantly lower in asymptomatic contact persons (15.4 %, p < 0.0001). In contact persons without symptoms the ct values of the PCR assays were significantly higher (5-7 threshold cycles) than in outpatients, and ct values were significantly negative correlated to the SARS-CoV-2-IgG ratio, suggesting a lower viral load as a possible explanation for lower rate of seropositivity. In summary, our study shows that serological response to SARS-CoV-2 in outpatients including asymptomatic persons is less pronounced than in hospitalized patients. Further controlled studies are urgently needed to determine serological response in outpatients and asymptomatic persons since this is the main target population for seroepidemiological investigations.

On-site CAD templates reduce surgery time for complex craniostenosis repair in infants: a new method

INTRODUCTION

The surgical correction of craniostenosis in children is a time-consuming and taxing procedure. To facilitate this procedure, especially in infants with complex craniostenosis, we refined the computer-aided design and manufacturing technique (CAD/CAM) based on computed tomography (CT)-generated DICOM data. We used cutting guides and molding templates, which allowed the surgeon to reshape and fixate the supraorbital bar extracorporeally on a side table and to control the intracorporal fit without removing the template.

METHOD AND PATIENTS

To compare our traditional concept with the possibility of preoperative virtual planning (PVP) technique, the surgical treatment and courses of 16 infants with complex craniostenosis following fronto-orbital advancement (FOA) (age range 8-15 months) were analyzed in two groups (group 1: traditional, control group n = 8, group 2: CAD/CAM planned, n = 8).

RESULTS

While in both groups, the head accurately reshaped postoperatively during the follow-up; the CAD group 2 showed a significantly shorter operating time with a mean of 4 h 25 min compared with group 1 with a mean of 5 h 37 min (p = 0.038). Additionally, the CAD group 2 had a significantly lower volume of blood loss (380 ml vs. 575 ml mean, p = 0.047), lower blood transfusion volume (285 ml vs. 400 ml mean, p = 0.108), lower fresh frozen plasma (FFP) volume (140 ml vs. 275 ml mean, p = 0.019), shorter stay in the pediatric intensive care unit (PICU) (3 vs. 5 days mean (p = 0.002), and shorter total length of hospital stay (6 days vs. 8 days mean, p = 0.002).

CONCLUSION

CAD/CAM cutting guides and templates offer optimizing operative efficiency, precision, and accuracy in craniostenosis surgery in infants. As shown in this single-center observational study, the use of on-site templates significantly accelerates the reconstruction of the bandeau. The virtual 3D planning technique increases surgical precision without discernible detrimental effects.

Evaluation of a new combined Western and line blot assay (EUROLINE-WB) for diagnosis and species identification of Echinococcus infection in humans

Serological detection of echinococcosis is crucial for diagnosis and management. We evaluated the new blot assay Euroline-WB (ELB, Euroimmun) which consists of a Western blot with Echinococcus multilocularis (E.m.) vesicle antigens and a line blot part with recombinant antigens from E. granulosus (E.g., genus-specific EgAgB) and E.m. (species-specific Em18 and Em95), in comparison to a commercial Western Blot (EWB, LDBio) for detection and species differentiation of echinococcosis within routine laboratory diagnostics. Thirty-five serum samples from 35 patients classified according to a standardized classification were included in the analysis. Out of 24 cases of proven and probable infection with E.m. or E.g. 16 (66.7%) and 15 (62.5%) were correctly identified on species level by EWB and ELB, respectively. False Echinococcus species were assigned in two cases by EWB but none by ELB. Negative blot results in patients with proven infections were noticed in 8.3% (ELB) compared to 4.2% (EWB), but were limited to patients with antiparasitic therapy or post-surgery indicating a treatment-induced loss of antibody activity. Thus, identification of Echinococcus infection at least on the genus level was possible in 23/24 (95.8%) and 19/24 (79.2%) of patients by EWB and ELB (or 22/24 patients (91.7%) including borderline results of ELB), respectively. Recombinant Em18 and Em95 were highly specific for detection of E.m. infection but differed in sensitivity (Em18 56% and 80 %, and Em95 22% and 20% in proven and probable infections, respectively). Advantages of ELB are the standardized analysis of the banding pattern by EUROLineScan software and a faster turn-around-time.

Single-use versus reusable ureterorenoscopes for retrograde intrarenal surgery (RIRS): systematic comparative analysis of physical and optical properties in three different devices

INTRODUCTION

Retrograde intrarenal surgery (RIRS) represents a standard option for kidney stone removal. However, RIRS is considered a cost-intensive procedure. Single-use flexible ureterorenoscopes have been introduced to improve budget predictability in RIRS. We assessed differences in physical and optical properties of single-use devices compared to standard reusable endoscopes.

METHODS

In two single-use (LithoVue™, Boston Scientific; Pusen Uscope UE3011™), and one reusable ureterorenoscope (Flex-Xc™, Karl Storz), we investigated flow rates, deflection, illuminance, and intrapelvic pressure in a porcine kidney model. Subjective image quality was assessed using a standardized questionnaire. Common insertable devices were applied to investigate additional influence on physical properties.

RESULTS

Significant variability in maximum flow rates was observed (Flex-Xc™: 25.8 ml/min, LithoVue™: 30.3 ml/min, Pusen™: 33.4 ml/min, p < 0.05). Insertion of a guide wire resulted in the highest reduction of flow rates in all endoscopes. Flection led to a reduction of absolute flow rates up to 9.4% (Flex-Xc™). Light intensity at 20/50 mm distance was 9090 lx/1857 lx (Flex-Xc™) and 5733 lx/1032 lx (LithoVue™) and 2160 lx/428 lx (Pusen™), respectively (p < 0.05). Subjective image quality score was highest using the Flex-Xc™ endoscope. During manipulation, maximum intrarenal pressure up to 66 mmHg (Pusen™) was measured.

CONCLUSIONS

Significant differences in physical and optical properties of single-use or reusable flexible ureterorenoscopes are present, with putative influence on surgical efficacy and complications. Further comparative evaluation of single-use and reusable endoscopes in a clinical scenario is useful. Moreover, utilization of ureteral access sheaths may be considered to avoid renal damage.

Transurethral Resection of Bladder Tumors: Next-generation Virtual Reality Training for Surgeons

BACKGROUND

The number of virtual reality (VR) simulators is increasing. The aim of this prospective trial was to determine the benefit of VR cystoscopy (UC) and transurethral bladder tumor resection (TURBT) training in students.

DESIGN, SETTING, AND PARTICIPANTS

Medical students without endoscopic experience (n=51, median age=25 yr, median 4th academic year) were prospectively randomized into groups A and B. After an initial VR-UC and VR-TURBT task, group A (n=25) underwent a video-based tutorial by a skilled expert. Group B (n=26) was trained using a VR training program (Uro-Trainer). Following the training, every participant performed a final VR-UC and VR-TURBT task. Performance indicators were recorded via the simulator. Data was analyzed by Mann-Whitney U test.

INTERVENTION

VR cystoscopy and TURBT.

RESULTS AND LIMITATIONS

No baseline and post-training differences were found for VR-UC between groups. During baseline, VR-TURBT group A showed higher inspected bladder surface than group B (56% vs 73%, p=0.03). Subgroup analysis detected differences related to sex before training (male: 31.2% decreased procedure time; 38.1% decreased resectoscope movement; p=0.02). After training, significant differences in procedure time (3.9min vs 2.7min, p=0.007), resectoscope movement (857mm vs 529mm, p=0.005), and accidental bladder injury (n=3.0 vs n=0.88, p=0.003) were found. Male participants showed reduced blood loss (males: 3.92ml vs females: 10.12ml; p=0.03) after training.

CONCLUSIONS

Measuring endoscopic skills within a virtual environment can be done easily. Short training improved efficacy and safety of VR-TURBT. Nevertheless, transfer of improved VR performance into real world surgery needs further clarification.

PATIENT SUMMARY

We investigated how students without endoscopic experience profit from simulation-based training. The safe environment and repeated simulations can improve the surgical training. It may be possible to enhance patient's safety and the training of surgeons in long term.

Impact of variant microscopic interpretation of the uCyt+ immunocytological urine test for the detection of bladder cancer

BACKGROUND

Urinary marker tests for bladder cancer (BC) detection and surveillance represent a desirable approach to diagnosis and follow-up. The SCIMEDX uCyt+ assay detects antigens expressed by BC cells (mucin glycoprotein and carcinoembryonic antigen) using green and red fluorescence and is interpreted according to specific manufacturer's recommendations. In the present study, we evaluated divergent approaches of numeric and morphological analysis of uCyt+ to generate a rationale for alternative test interpretation strategies.

METHODS

A total of 444 patients with hematuria and without history of BC underwent uCyt+ analysis, cystoscopy and histological examination of tissue biopsies. Beside positive cells according to the manufacturer's definition (definitely positive cells, DPC), (i) cells showing borderline character (borderline cells, BLC), and (ii) cells with staining present below defined border (subliminal cells, SLC) were included into the analytical algorithm. Different cut-off levels for cell counts (>0, ≥3, ≥5) were evaluated separately with regard to their diagnostic accuracy. Moreover, the influence of clinical factors on test results were evaluated.

RESULTS

Adding BLC at a cut-off of ≥3 cells resulted in Area Under the Curve (AUC) of 0.70 for green and 0.77 for red fluorescence, respectively. Adding SLC led to reduced AUC (0.62 and 0.73, respectively). Male gender was significantly associated with false positive results in the "best AUC" groups (P = .0101). No further correlations to clinical influencing factors were observed.

CONCLUSIONS

Adding microscopic BLC as test-positive and adjusting cut-off level for the interpretation of uCyt+ may improve assay performance independent of clinical factors.

Anticoagulation management during multivessel coronary artery bypass grafting: a randomized trial comparing individualized heparin management and conventional hemostasis management

BACKGROUND

Individualized heparin management (IHM) uses heparin dose-response curves to improve hemostasis management during cardiac surgery as compared with activated clotting time-based methods.

OBJECTIVES

IHM was compared with conventional hemostasis management (CHM) in a randomized, prospective study (ID DRKS00007580).

METHODS

One-hundred and twenty patients undergoing multivessel coronary artery bypass grafting (CABG) were enrolled. Heparin and protamine consumption, blood losses, blood transfusions and administration of hemostatic agents were recorded. Time courses of platelet counts and of coagulation parameters were determined. Coagulation was analyzed at intensive care unit (ICU) arrival by thromboelastometry.

RESULTS

IHM patients received significantly lower initial heparin doses (289.3IU kg(-1) [interquartile range (IQR) 221.5-376.2 IU kg(-1) ] versus 350.5 IU kg(-1) [IQR 346.8-353.7 IU kg(-1) ], P < 0.0001) but similar total heparin doses (418.5 IU kg(-1) [IQR 346.9-590.5 IU kg(-1) ] versus 435.8 IU kg(-1) [IQR 411.7-505.1 IU kg(-1) ]). IHM patients received significantly less protamine, resulting in protamine/total heparin ratios of 0.546 [IQR 0.469-0.597] versus 0.854 [IQR 0.760-0.911] in CHM patients (P < 0.0001). Activated partial thromboplastin time (50.5 s [IQR 40.0-60.0 s] versus 37.0 s [IQR 33.0-40.0 s], P < 0.0001), activated clotting time (136 s [IQR 129.0-150.5 s] versus 126.5 s [IQR 120.3-134.0 s], P = 0.0002) and INTEM clotting times (215 s [IQR 192-237] versus 201 s [IQR 191-216 s], P = 0.0397) were significantly longer in IHM patients than in CHM patients at ICU arrival, with no difference in prothrombin time (P = 0.538). IHM patients lost significantly more blood within 12 h postoperatively (420 mL [IQR 337.5-605.0 mL] versus 345 mL [IQR 230.0-482.5 mL], P = 0.0041), and required significantly more hemostatic agents to control bleeding. Red blood cell transfusion requirements and time courses of platelet counts did not differ between groups.

CONCLUSIONS

Multivessel CABG patients did not benefit from IHM in comparison with our established protocol based on activated clotting time.

Apolipoprotein B100 is a suppressor of Staphylococcus aureus-induced innate immune responses in humans and mice

Plasma lipoproteins such as LDL (low-density lipoprotein) are important therapeutic targets as they play a crucial role in macrophage biology and metabolic disorders. The impact of lipoprotein profiles on host defense pathways against Gram-positive bacteria is poorly understood. In this report, we discovered that human serum lipoproteins bind to lipoteichoic acid (LTA) from Staphylococcus aureus and thereby alter the immune response to these bacteria. Size-exclusion chromatography and solid-phase-binding analysis of serum revealed the direct interaction of LTA with apolipoproteins (Apo) B100, ApoA1, and ApoA2. Only ApoB100 and the corresponding LDL exerted biological effects as this binding significantly inhibited LTA-induced cytokine releases from human and murine immune cells. Serum from hypercholesterolemic mice or humans significantly diminished cytokine induction in response to S. aureus or its LTA. Sera taken from the patients with familial hypercholesterolemia before and after ApoB100-directed immuno-apheresis confirmed that ApoB100 inhibited LTA-induced inflammation in humans. In addition, mice in which LDL secretion was pharmacologically inhibited, displayed significantly increased serum cytokine levels upon infection with S. aureus in vivo. The present study identifies ApoB100 as an important suppressor of innate immune activation in response to S. aureus and its LTA.

Elevated adaptive immune responses are associated with latent infections of Wuchereria bancrofti

In order to guarantee the fulfillment of their complex lifecycle, adult filarial nematodes release millions of microfilariae (MF), which are taken up by mosquito vectors. The current strategy to eliminate lymphatic filariasis as a public health problem focuses upon interrupting this transmission through annual mass drug administration (MDA). It remains unclear however, how many rounds of MDA are required to achieve low enough levels of MF to cease transmission. Interestingly, with the development of further diagnostic tools a relatively neglected cohort of asymptomatic (non-lymphedema) amicrofilaremic (latent) individuals has become apparent. Indeed, epidemiological studies have suggested that there are equal numbers of patent (MF⁺) and latent individuals. Since the latter represent a roadblock for transmission, we studied differences in immune responses of infected asymptomatic male individuals (n = 159) presenting either patent (n = 92 MF⁺) or latent (n = 67 MF⁻) manifestations of Wuchereria bancrofti. These individuals were selected on the basis of MF, circulating filarial antigen in plasma and detectable worm nests. Immunological profiles of either Th1/Th17, Th2, regulatory or innate responses were determined after stimulation of freshly isolated PBMCs with either filarial-specific extract or bystander stimuli. In addition, levels of total and filarial-specific antibodies, both IgG subclasses and IgE, were ascertained from plasma. Results from these individuals were compared with those from 22 healthy volunteers from the same endemic area. Interestingly, we observed that in contrast to MF⁺ patients, latent infected individuals had lower numbers of worm nests and increased adaptive immune responses including antigen-specific IL-5. These data highlight the immunosuppressive status of MF⁺ individuals, regardless of age or clinical hydrocele and reveal immunological profiles associated with latency and immune-mediated suppression of parasite transmission.

The tropical helminth infection lymphatic filariasis affects more than 120 million people worldwide and is considered a major public health concern. Over 90% of infections are elicited by Wucheria bancrofti and adult worms reside in the lymphatic system releasing millions of microfilariae (MF), which periodically circulate in the blood. New diagnostic tools have provided a method to determine asymptomatic patients that are amicrofilaremic: a subset of individuals that have so far been neglected but are of special interest since these patients represent a dead end in terms of parasite transmission. Therefore, we were interested in determining whether the absence of MF was associated with distinct immunological profiles and observed that indeed responses in MF⁺ patients were dampened. From the viewpoint of the helminth such overall suppression of immune responses may facilitate MF transmission. Latent individuals however, presented elevated filarial specific responses and extrapolating these findings to the host provides novel insight into possible protective mechanisms which either actively hinders the release of MF from worms or their travel to the periphery. Further research into these aspects may broaden the range of strategies currently employed to reduce transmission and in turn eliminate bancroftian filariasis.

HMOX1 gene promoter alleles and high HO-1 levels are associated with severe malaria in Gambian children

Heme oxygenase 1 (HO-1) is an essential enzyme induced by heme and multiple stimuli associated with critical illness. In humans, polymorphisms in the HMOX1 gene promoter may influence the magnitude of HO-1 expression. In many diseases including murine malaria, HO-1 induction produces protective anti-inflammatory effects, but observations from patients suggest these may be limited to a narrow range of HO-1 induction, prompting us to investigate the role of HO-1 in malaria infection. In 307 Gambian children with either severe or uncomplicated P. falciparum malaria, we characterized the associations of HMOX1 promoter polymorphisms, HMOX1 mRNA inducibility, HO-1 protein levels in leucocytes (flow cytometry), and plasma (ELISA) with disease severity. The (GT)(n) repeat polymorphism in the HMOX1 promoter was associated with HMOX1 mRNA expression in white blood cells in vitro, and with severe disease and death, while high HO-1 levels were associated with severe disease. Neutrophils were the main HO-1-expressing cells in peripheral blood, and HMOX1 mRNA expression was upregulated by heme-moieties of lysed erythrocytes. We provide mechanistic evidence that induction of HMOX1 expression in neutrophils potentiates the respiratory burst, and propose this may be part of the causal pathway explaining the association between short (GT)(n) repeats and increased disease severity in malaria and other critical illnesses. Our findings suggest a genetic predisposition to higher levels of HO-1 is associated with severe illness, and enhances the neutrophil burst leading to oxidative damage of endothelial cells. These add important information to the discussion about possible therapeutic manipulation of HO-1 in critically ill patients.

Down-regulation of hypusine biosynthesis in Plasmodium by inhibition of S-adenosyl-methionine-decarboxylase

An important issue facing global health today is the need for new, effective and affordable drugs against malaria, particularly in resource-poor countries. Moreover, the currently available antimalarials are limited by factors ranging from parasite resistance to safety, compliance, cost and the current lack of innovations in medicinal chemistry. Depletion of polyamines in the intraerythrocytic phase of P. falciparum is a promising strategy for the development of new antimalarials since intracellular levels of putrescine, spermidine and spermine are increased during cell proliferation. S-adenosyl-methionine-decarboxylase (AdoMETDC) is a key enzyme in the biosynthesis of spermidine. The AdoMETDC inhibitor CGP 48664A, known as SAM486A, inhibited the separately expressed plasmodial AdoMETDC domain with a Km( i ) of 3 microM resulting in depletion of spermidine. Spermidine is an important precursor in the biosynthesis of hypusine. This prompted us to investigate a downstream effect on hypusine biosynthesis after inhibition of AdoMETDC. Extracts from P. falciparum in vitro cultures that were treated with 10 microM SAM 486A showed suppression of eukaryotic initiation factor 5A (eIF-5A) in comparison to the untreated control in two-dimensional gel electrophoresis. Depletion of eIF-5A was also observed in Western blot analysis with crude protein extracts from the parasite after treatment with 10 microM SAM486A. A determination of the intracellular polyamine levels revealed an approximately 27% reduction of spemidine and a 75% decrease of spermine while putrescine levels increased to 36%. These data suggest that inhibition of AdoMetDc provides a novel strategy for eIF-5A suppression and the design of new antimalarials.

Distinct roles for FOXP3 and FOXP3 CD4 T cells in regulating cellular immunity to uncomplicated and severe Plasmodium falciparum malaria

Failure to establish an appropriate balance between pro- and anti-inflammatory immune responses is believed to contribute to pathogenesis of severe malaria. To determine whether this balance is maintained by classical regulatory T cells (CD4(+) FOXP3(+) CD127(-/low); Tregs) we compared cellular responses between Gambian children (n = 124) with severe Plasmodium falciparum malaria or uncomplicated malaria infections. Although no significant differences in Treg numbers or function were observed between the groups, Treg activity during acute disease was inversely correlated with malaria-specific memory responses detectable 28 days later. Thus, while Tregs may not regulate acute malarial inflammation, they may limit memory responses to levels that subsequently facilitate parasite clearance without causing immunopathology. Importantly, we identified a population of FOXP3(-), CD45RO(+) CD4(+) T cells which coproduce IL-10 and IFN-gamma. These cells are more prevalent in children with uncomplicated malaria than in those with severe disease, suggesting that they may be the regulators of acute malarial inflammation.

Filarial infection induces protection against P. berghei liver stages in mice

Chronic helminth infections such as filariasis in human hosts can be life long, since parasites are equipped with a repertoire of immune evasion strategies. In many areas where helminths are prevalent, other infections such as malaria are co-endemic. It is still an ongoing debate, how one parasite alters immune responses against another. To dissect the relationships between two different parasites residing in the same host, we established a murine model of co-infection with the filarial nematode Litomosoides sigmodontis and the malaria parasite Plasmodium berghei (ANKA strain). We found that filarial infection of BALB/c mice leads to protection against a subsequent P. berghei sporozoite infection in one-third of co-infected mice, which did not develop blood-stage malaria. This finding did not correlate with adult worm loads, however it did correlate with the presence of microfilariae in blood. Interestingly, protection was abrogated in IL-10-deficient mice. Thus, murine filariasis, in particular when it is a patent infection, is able to modify the immunological balance to induce protection against an otherwise deadly Plasmodium infection and is therefore able to influence the course of malaria in favour of the host.

Cellular trafficking of lipoteichoic acid and Toll-like receptor 2 in relation to signaling: role of CD14 and CD36

Lipoteichoic acid (LTA) is a central inducer of inflammatory responses caused by Gram-positive bacteria, such as Staphylococcus aureus, via activation of TLR2. Localization of TLR2 in relation to its coreceptors may be important for function. This study explores the signaling, uptake, and trafficking pattern of LTA in relation to expression of TLR2 and its coreceptors CD36 and CD14 in human monocytes. We found TLR2 expressed in early endosomes, late endosomes/lysosomes, and in Rab-11-positive compartments but not in the Golgi apparatus or endoplasmic reticulum (ER). Rapid internalization of fluorescently labeled LTA was observed in human monocytes, colocalizing with markers for early and late endosomes, lysosomes, ER, and Golgi network. Blocking CD14 and CD36 with antibodies inhibited LTA binding and LTA-induced TNF release from monocytes, emphasizing an important role for both molecules as coreceptors for TLR2. Importantly, blocking CD36 did not affect TNF release induced by N-palmitoyl-S-[2,3-bis(palmitoyloxy)-(2R,S)-propyl]-(R)-cysteinyl-seryl-(lysyl)3-lysine or LPS. Expression of CD14 markedly enhanced LTA binding to the plasma membrane and also enhanced NF-kappaB activation. LTA internalization, but not NF-kappaB activation, was inhibited in Dynamin-I K44A dominant-negative transfectants, suggesting that LTA is internalized by receptor-mediated endocytosis but that internalization is not required for signaling. In fact, immobilizing LTA and thereby inhibiting internalization resulted in enhanced TNF release from monocytes. Our results suggest that LTA signaling preferentially occurs at the plasma membrane, is independent of internalization, and is facilitated by CD36 and CD14 as coreceptors for TLR2.

Cytokine induction by Gram-positive bacteria

Despite similar clinical relevance of Gram-positive and Gram-negative infections, immune activation by Gram-positive bacteria is by far less well understood than immune activation by Gram-negative bacteria. Our group has made available highly purified lipoteichoic acids (LTA) as a key Gram-positive immunostimulatory component. We have characterized the reasons for lower potency of LTA compared to Gram-negative lipopolysaccharide (LPS), identifying lack of IL-12/IFNgamma induction as a general characteristic of TLR2 agonists, and need for presentation of LTA on surfaces for enhanced immunostimulatory potency, as major aspects. Aspects of chemokine induction, where LTA is more potent than LPS, have been addressed. Furthermore, novel complement and plant defence activation, as well as CD36 as a new LTA receptor, were identified. The bacterial costimuli and modulators of LTA inducible responses are being investigated: LTA isolated from so far 16 bacterial species, although different in structure, behave remarkably similar while whole live and killed bacteria differ with regard to the pattern of induced responses. The purification and characterization of the respective components of the bacterial cell wall has begun.

Gender difference in cytokine secretion on immune stimulation with LPS and LTA

Immune defense capacity differs between men and women. Whereas men are more prone to infection and sepsis, women more commonly develop autoimmune diseases. We investigated the difference in cytokine secretion between males and females in response to different immune stimuli. Whole blood from 154 healthy volunteers (age 24 +/- 5.2; 82 females, 72 males) was collected within 2 h on 2 consecutive days. Blood from males produced significantly more tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6, and IL-8 than blood from females in response to a high concentration of either lipopolysaccharide (LPS) or lipoteichoic acid (LTA), whereas IL-10 and interferon-gamma (IFN-gamma) secretion did not differ. Normalization of cytokine measurement to individual monocyte counts cancelled these differences for all parameters except TNF-alpha. Stimulation with a lower concentration of LPS (100 pg/mL) produced even stronger differences in cytokine release, which were not cancelled by normalization to the producing cells. The coefficients of variation (CV) of the LPS-induced and LTA-induced cytokine responses were higher in blood from women than men for all parameters and stimuli measured. Thus, the stronger innate immune response of males in comparison to females appears to stem not only from a difference in monocyte counts but also from the steepness of the response curve.

Synthesis of Staphylococcus aureus lipoteichoic acid derivatives for determining the minimal structural requirements for cytokine induction

For the investigation of the minimal structural requirements for cytokine induction, Staphylococcus aureus lipoteichoic acid derivatives with two, three, four, and five glycerophosphate backbone moieties, carrying each a d-alanyl residue, were needed. Based on two different glycerophosphate building blocks and 6b-O-phosphitylated gentiobiosyl diacylglycerol the desired target molecules (compounds 1-4) could be readily obtained and provided for biological studies.

A Staphylococcus aureus lipoteichoic acid (LTA) derived structural variant with two diacylglycerol residues

Based on 1,2-O-isopropylidene-sn-glycerol five chiral building blocks containing differently modified glycerol residues were required for the synthesis of the target molecule 2. One of these building blocks is diacylglyceryl beta-gentiobioside carrying a phosphite residue at 6b-O position. Ligation of these five building blocks led to the desired glycerol phosphate backbone to which d-alanyl residues were attached, thus generating after O-deprotection the target molecule 2, a bisamphiphilic structural variant of Staphylococcus aureus LTA. This compound displayed higher potency in terms of cytokine release by human blood leukocytes than the monoamphiphilic variant LTA.

Inflammatory neurodegeneration induced by lipoteichoic acid from Staphylococcus aureus is mediated by glia activation, nitrosative and oxidative stress, and caspase activation

In this study we investigated the mechanisms of neuronal cell death induced by lipoteichoic acid (LTA) and muramyl dipeptide (MDP) from Gram-positive bacterial cell walls using primary cultures of rat cerebellum granule cells (CGCs) and rat cortical glial cells (astrocytes and microglia). LTA (+/- MDP) from Staphylococcus aureus induced a strong inflammatory response of both types of glial cells (release of interleukin-1beta, tumour necrosis factor-alpha and nitric oxide). The death of CGCs was caused by activated glia because in the absence of glia (treatment with 7.5 microm cytosine-d-arabinoside to inhibit non-neuronal cell proliferation) LTA + MDP did not cause significant cell death (less than 20%). In addition, staining with rhodamine-labelled LTA confirmed that LTA was bound only to microglia and astrocytes (not neurones). Neuronal cell death induced by LTA (+/- MDP)-activated glia was partially blocked by an inducible nitric oxide synthase inhibitor (1400 W; 100 microm), and completely blocked by a superoxide dismutase mimetic [manganese (III) tetrakis (4-benzoic acid)porphyrin chloride; 50 microm] and a peroxynitrite scavenger [5,10,15,20-tetrakis (4-sulfonatophenyl) porphyrinato iron (III); 100 microm] suggesting that nitric oxide and peroxynitrite contributed to LTA-induced cell death. Moreover, neuronal cell death was inhibited by selective inhibitors of caspase-3 (z-DEVD-fmk; 50 microm) and caspase-8 (z-Ile-Glu(O-Me)-Thr-Asp(O-Me) fluoromethyl ketone; 50 microm) indicating that they were involved in LTA-induced neuronal cell death.

Definition of structural prerequisites for lipoteichoic acid-inducible cytokine induction by synthetic derivatives

The controversy about the immune stimulatory properties of lipoteichoic acid (LTA) from Staphylococcus aureus was solved recently by showing decomposition and inactivation of LTA obtained by conventional purification strategies, as well as pronounced LPS contamination of commercial preparations. By introducing a novel preparation method, the structure of bioactive LTA was elucidated. This structure was confirmed by chemical synthesis. In this work, synthetic LTA derivatives were employed to study the structure-function relationship of cytokine induction in human monocytes. Synthetic LTA induced the same cytokine pattern as highly purified natural LTA. The gentiobiose core could be omitted without affecting bioactivity. The polyglycerophosphate backbone amplified the response to the lipid anchor ( approximately 100-fold) only when substituted with D-alanine, whereas alpha-D-N-acetylglucosamine substituents could be omitted. Replacing D-alanine substituents with L-alanine reduced the activity of the molecule at least 10-fold, indicating stereoselectivity. These results define for the first time the crucial patterns required for the immune recognition of LTA.